/* roulang page: index */
/* ===== Design Variables ===== */
        :root {
            --color-primary: #0b1a2e;
            --color-primary-light: #0f2240;
            --color-brand: #1a6bff;
            --color-brand-hover: #3a85ff;
            --color-accent1: #00d4ff;
            --color-accent2: #7b61ff;
            --color-bg: #060e1a;
            --color-card-bg: rgba(255, 255, 255, 0.04);
            --color-card-bg-hover: rgba(255, 255, 255, 0.08);
            --color-text: #e8edf5;
            --color-text-secondary: #8a9bb5;
            --color-text-emphasis: #ffffff;
            --color-border: rgba(255, 255, 255, 0.06);
            --color-border-hover: rgba(255, 255, 255, 0.12);
            --font-family: 'PingFang SC', 'Microsoft YaHei', 'Helvetica Neue', Arial, sans-serif;
            --radius-card: 12px;
            --radius-inner: 8px;
            --radius-button: 6px;
            --shadow-card: 0 8px 32px rgba(0, 0, 0, 0.3);
            --shadow-card-hover: 0 12px 48px rgba(0, 0, 0, 0.5);
            --transition-base: 0.3s ease;
            --max-width: 1280px;
            --padding-container: 24px;
            --gap-section: 6rem;
            --gap-section-inner: 3rem;
        }

        /* ===== Reset & Base ===== */
        *,
        *::before,
        *::after {
            box-sizing: border-box;
            margin: 0;
            padding: 0;
        }

        html {
            scroll-behavior: smooth;
            -webkit-font-smoothing: antialiased;
            -moz-osx-font-smoothing: grayscale;
        }

        body {
            font-family: var(--font-family);
            font-size: 1rem;
            line-height: 1.7;
            color: var(--color-text);
            background-color: var(--color-bg);
            min-height: 100vh;
        }

        a {
            color: var(--color-brand);
            text-decoration: none;
            transition: color var(--transition-base);
        }
        a:hover {
            color: var(--color-brand-hover);
        }
        a:focus-visible {
            outline: 2px solid var(--color-brand);
            outline-offset: 2px;
            border-radius: 2px;
        }

        img {
            max-width: 100%;
            height: auto;
            display: block;
            border-radius: var(--radius-inner);
        }

        button,
        input,
        select,
        textarea {
            font-family: inherit;
            font-size: inherit;
            line-height: inherit;
        }

        button {
            cursor: pointer;
            border: none;
            background: none;
            color: inherit;
        }
        button:focus-visible {
            outline: 2px solid var(--color-brand);
            outline-offset: 2px;
        }

        ul,
        ol {
            list-style: none;
        }

        /* ===== Container ===== */
        .container {
            max-width: var(--max-width);
            margin: 0 auto;
            padding-left: var(--padding-container);
            padding-right: var(--padding-container);
            width: 100%;
        }

        /* ===== Glass Morphism ===== */
        .glass {
            background: var(--color-card-bg);
            backdrop-filter: blur(16px);
            -webkit-backdrop-filter: blur(16px);
            border: 1px solid var(--color-border);
            border-radius: var(--radius-card);
            box-shadow: var(--shadow-card);
            transition: all var(--transition-base);
        }
        .glass:hover {
            background: var(--color-card-bg-hover);
            border-color: var(--color-border-hover);
            box-shadow: var(--shadow-card-hover);
            transform: translateY(-2px);
        }

        /* ===== Glow Button ===== */
        .btn-glow {
            display: inline-flex;
            align-items: center;
            justify-content: center;
            padding: 12px 32px;
            border-radius: var(--radius-button);
            font-weight: 600;
            font-size: 1rem;
            line-height: 1.4;
            color: #fff;
            background: linear-gradient(135deg, var(--color-brand), #0f4dcc);
            box-shadow: 0 4px 20px rgba(26, 107, 255, 0.3);
            transition: all var(--transition-base);
            border: none;
            text-align: center;
            gap: 8px;
        }
        .btn-glow:hover {
            box-shadow: 0 6px 30px rgba(26, 107, 255, 0.5);
            transform: scale(1.02);
            color: #fff;
        }
        .btn-glow:active {
            transform: scale(0.98);
        }
        .btn-glow:focus-visible {
            outline: 2px solid var(--color-accent1);
            outline-offset: 2px;
        }

        .btn-glow-outline {
            background: transparent;
            border: 1.5px solid rgba(26, 107, 255, 0.6);
            box-shadow: 0 4px 20px rgba(26, 107, 255, 0.15);
            color: var(--color-text);
        }
        .btn-glow-outline:hover {
            background: rgba(26, 107, 255, 0.08);
            border-color: var(--color-brand);
            box-shadow: 0 6px 30px rgba(26, 107, 255, 0.3);
            color: var(--color-text-emphasis);
        }

        .btn-glow-large {
            padding: 16px 48px;
            font-size: 1.125rem;
            border-radius: var(--radius-button);
        }

        .btn-glow-accent2 {
            background: linear-gradient(135deg, var(--color-accent2), #5a3fd9);
            box-shadow: 0 4px 20px rgba(123, 97, 255, 0.3);
        }
        .btn-glow-accent2:hover {
            box-shadow: 0 6px 30px rgba(123, 97, 255, 0.5);
        }

        /* ===== Badge / Tag ===== */
        .badge {
            display: inline-block;
            padding: 4px 14px;
            border-radius: 999px;
            font-size: 0.75rem;
            font-weight: 500;
            line-height: 1.4;
            background: rgba(123, 97, 255, 0.2);
            color: var(--color-accent2);
            border: 1px solid rgba(123, 97, 255, 0.3);
        }
        .badge-brand {
            background: rgba(26, 107, 255, 0.2);
            color: var(--color-brand);
            border-color: rgba(26, 107, 255, 0.3);
        }
        .badge-accent {
            background: rgba(0, 212, 255, 0.15);
            color: var(--color-accent1);
            border-color: rgba(0, 212, 255, 0.25);
        }

        /* ===== Section ===== */
        .section {
            padding: var(--gap-section) 0;
        }
        .section-title {
            font-size: 2.25rem;
            font-weight: 600;
            line-height: 1.25;
            letter-spacing: -0.01em;
            margin-bottom: 1rem;
            color: var(--color-text-emphasis);
        }
        .section-subtitle {
            font-size: 1.125rem;
            color: var(--color-text-secondary);
            max-width: 680px;
            margin-bottom: var(--gap-section-inner);
        }
        .section-header {
            text-align: center;
            margin-bottom: var(--gap-section-inner);
        }
        .section-header .section-subtitle {
            margin-left: auto;
            margin-right: auto;
        }

        /* ===== Grid System ===== */
        .grid-12 {
            display: grid;
            grid-template-columns: repeat(12, 1fr);
            gap: 24px;
        }
        .grid-3 {
            display: grid;
            grid-template-columns: repeat(3, 1fr);
            gap: 24px;
        }
        .grid-2 {
            display: grid;
            grid-template-columns: repeat(2, 1fr);
            gap: 24px;
        }
        .grid-4 {
            display: grid;
            grid-template-columns: repeat(4, 1fr);
            gap: 24px;
        }

        /* ===== Header / Nav ===== */
        .site-header {
            position: fixed;
            top: 0;
            left: 0;
            right: 0;
            z-index: 1000;
            background: rgba(6, 14, 26, 0.92);
            backdrop-filter: blur(20px);
            -webkit-backdrop-filter: blur(20px);
            border-bottom: 1px solid rgba(255, 255, 255, 0.05);
            height: 72px;
            transition: background var(--transition-base);
        }
        .site-header .container {
            display: flex;
            align-items: center;
            justify-content: space-between;
            height: 100%;
        }

        .nav-logo {
            display: flex;
            align-items: center;
            gap: 10px;
            font-size: 1.4rem;
            font-weight: 600;
            color: var(--color-text-emphasis);
            letter-spacing: -0.02em;
        }
        .nav-logo svg {
            width: 32px;
            height: 32px;
            flex-shrink: 0;
        }
        .nav-logo span {
            background: linear-gradient(135deg, #e8edf5, var(--color-brand));
            -webkit-background-clip: text;
            -webkit-text-fill-color: transparent;
            background-clip: text;
        }
        .nav-logo:hover {
            color: var(--color-text-emphasis);
        }

        .nav-center {
            display: flex;
            align-items: center;
            gap: 2rem;
        }
        .nav-center a {
            color: var(--color-text-secondary);
            font-size: 0.95rem;
            font-weight: 500;
            position: relative;
            padding: 4px 0;
            transition: color var(--transition-base);
        }
        .nav-center a::after {
            content: '';
            position: absolute;
            bottom: -2px;
            left: 0;
            width: 0;
            height: 2px;
            background: var(--color-brand);
            border-radius: 2px;
            transition: width var(--transition-base);
            box-shadow: 0 0 8px rgba(26, 107, 255, 0.5);
        }
        .nav-center a:hover {
            color: var(--color-text-emphasis);
        }
        .nav-center a:hover::after {
            width: 100%;
        }
        .nav-center a.active {
            color: var(--color-brand);
        }
        .nav-center a.active::after {
            width: 100%;
        }

        .nav-right {
            display: flex;
            align-items: center;
            gap: 16px;
        }
        .nav-search {
            display: flex;
            align-items: center;
            background: rgba(255, 255, 255, 0.06);
            border: 1px solid rgba(255, 255, 255, 0.08);
            border-radius: 20px;
            padding: 6px 16px 6px 14px;
            transition: all var(--transition-base);
            min-width: 180px;
        }
        .nav-search:focus-within {
            border-color: var(--color-brand);
            background: rgba(255, 255, 255, 0.1);
            box-shadow: 0 0 16px rgba(26, 107, 255, 0.15);
        }
        .nav-search input {
            background: none;
            border: none;
            color: var(--color-text);
            font-size: 0.875rem;
            padding: 4px 0;
            width: 100%;
            outline: none;
        }
        .nav-search input::placeholder {
            color: var(--color-text-secondary);
        }
        .nav-search i {
            color: var(--color-text-secondary);
            font-size: 0.875rem;
            margin-right: 8px;
        }

        .nav-btn-login {
            padding: 8px 20px;
            border-radius: var(--radius-button);
            border: 1px solid rgba(255, 255, 255, 0.15);
            color: var(--color-text);
            font-weight: 500;
            font-size: 0.9rem;
            background: transparent;
            transition: all var(--transition-base);
        }
        .nav-btn-login:hover {
            border-color: var(--color-brand);
            color: var(--color-brand);
            background: rgba(26, 107, 255, 0.06);
        }

        .nav-btn-cta {
            padding: 8px 22px;
            border-radius: var(--radius-button);
            background: linear-gradient(135deg, var(--color-accent2), #5a3fd9);
            color: #fff;
            font-weight: 600;
            font-size: 0.9rem;
            box-shadow: 0 4px 16px rgba(123, 97, 255, 0.25);
            transition: all var(--transition-base);
        }
        .nav-btn-cta:hover {
            box-shadow: 0 6px 24px rgba(123, 97, 255, 0.4);
            transform: scale(1.02);
            color: #fff;
        }

        /* Hamburger */
        .nav-hamburger {
            display: none;
            flex-direction: column;
            gap: 5px;
            cursor: pointer;
            padding: 4px;
            background: none;
            border: none;
        }
        .nav-hamburger span {
            display: block;
            width: 26px;
            height: 2px;
            background: var(--color-text);
            border-radius: 2px;
            transition: all var(--transition-base);
        }
        .nav-hamburger.active span:nth-child(1) {
            transform: rotate(45deg) translate(5px, 5px);
        }
        .nav-hamburger.active span:nth-child(2) {
            opacity: 0;
        }
        .nav-hamburger.active span:nth-child(3) {
            transform: rotate(-45deg) translate(5px, -5px);
        }

        /* Mobile Nav */
        .mobile-nav {
            display: none;
            position: fixed;
            top: 72px;
            left: 0;
            right: 0;
            background: rgba(6, 14, 26, 0.98);
            backdrop-filter: blur(24px);
            -webkit-backdrop-filter: blur(24px);
            border-bottom: 1px solid var(--color-border);
            padding: 24px var(--padding-container);
            z-index: 999;
            flex-direction: column;
            gap: 16px;
        }
        .mobile-nav.open {
            display: flex;
        }
        .mobile-nav a {
            color: var(--color-text-secondary);
            font-size: 1.1rem;
            font-weight: 500;
            padding: 8px 0;
            border-bottom: 1px solid rgba(255, 255, 255, 0.04);
        }
        .mobile-nav a.active {
            color: var(--color-brand);
        }
        .mobile-nav a:last-child {
            border-bottom: none;
        }
        .mobile-nav .mobile-cta {
            margin-top: 8px;
        }
        .mobile-nav .mobile-cta .btn-glow {
            width: 100%;
            justify-content: center;
        }

        /* ===== Hero ===== */
        .hero {
            padding: 160px 0 100px;
            background: linear-gradient(135deg, #060e1a 0%, #0b1a2e 60%, #0f2240 100%);
            position: relative;
            overflow: hidden;
            min-height: 85vh;
            display: flex;
            align-items: center;
        }
        .hero::before {
            content: '';
            position: absolute;
            top: -30%;
            right: -10%;
            width: 70%;
            height: 140%;
            background: radial-gradient(ellipse at center, rgba(26, 107, 255, 0.08) 0%, transparent 70%);
            pointer-events: none;
        }
        .hero::after {
            content: '';
            position: absolute;
            bottom: -20%;
            left: -10%;
            width: 60%;
            height: 120%;
            background: radial-gradient(ellipse at center, rgba(123, 97, 255, 0.06) 0%, transparent 70%);
            pointer-events: none;
        }
        .hero .hero-bg-img {
            position: absolute;
            top: 0;
            left: 0;
            width: 100%;
            height: 100%;
            object-fit: cover;
            opacity: 0.15;
            pointer-events: none;
        }
        .hero .container {
            position: relative;
            z-index: 2;
        }
        .hero-content {
            max-width: 820px;
        }
        .hero h1 {
            font-size: 3.5rem;
            font-weight: 700;
            line-height: 1.2;
            letter-spacing: -0.02em;
            background: linear-gradient(135deg, #e8edf5 30%, var(--color-brand) 100%);
            -webkit-background-clip: text;
            -webkit-text-fill-color: transparent;
            background-clip: text;
            margin-bottom: 1.2rem;
        }
        .hero-sub {
            font-size: 1.25rem;
            font-weight: 300;
            letter-spacing: 0.05em;
            color: var(--color-text-secondary);
            margin-bottom: 2.5rem;
            max-width: 640px;
            line-height: 1.6;
        }
        .hero-actions {
            display: flex;
            gap: 16px;
            flex-wrap: wrap;
        }
        .hero-actions .btn-glow {
            padding: 16px 40px;
        }

        /* ===== Comparison Table ===== */
        .comparison {
            background: var(--color-bg);
        }
        .comparison-grid {
            display: grid;
            grid-template-columns: 1fr 1fr 1fr;
            gap: 20px;
        }
        .comparison-card {
            padding: 2rem 1.8rem;
            border-radius: var(--radius-card);
            background: var(--color-card-bg);
            backdrop-filter: blur(12px);
            -webkit-backdrop-filter: blur(12px);
            border: 1px solid var(--color-border);
            transition: all var(--transition-base);
            text-align: center;
        }
        .comparison-card:hover {
            border-color: var(--color-border-hover);
            transform: translateY(-4px);
            box-shadow: var(--shadow-card-hover);
        }
        .comparison-card.highlight {
            border-color: rgba(26, 107, 255, 0.3);
            background: rgba(26, 107, 255, 0.06);
            box-shadow: 0 0 30px rgba(26, 107, 255, 0.08);
            position: relative;
        }
        .comparison-card.highlight::before {
            content: '推荐';
            position: absolute;
            top: 14px;
            right: 14px;
            background: var(--color-brand);
            color: #fff;
            font-size: 0.7rem;
            font-weight: 600;
            padding: 2px 12px;
            border-radius: 999px;
            letter-spacing: 0.02em;
        }
        .comparison-card .plan-name {
            font-size: 1.4rem;
            font-weight: 600;
            margin-bottom: 4px;
            color: var(--color-text-emphasis);
        }
        .comparison-card .plan-price {
            font-size: 2.5rem;
            font-weight: 700;
            color: var(--color-text-emphasis);
            margin: 12px 0 4px;
        }
        .comparison-card .plan-price span {
            font-size: 1rem;
            font-weight: 400;
            color: var(--color-text-secondary);
        }
        .comparison-card .plan-desc {
            font-size: 0.9rem;
            color: var(--color-text-secondary);
            margin-bottom: 20px;
        }
        .comparison-card ul {
            text-align: left;
            margin: 16px 0 24px;
            padding: 0;
        }
        .comparison-card ul li {
            padding: 8px 0;
            border-bottom: 1px solid rgba(255, 255, 255, 0.04);
            display: flex;
            align-items: center;
            gap: 10px;
            font-size: 0.9rem;
            color: var(--color-text-secondary);
        }
        .comparison-card ul li i {
            color: var(--color-brand);
            font-size: 0.85rem;
            width: 18px;
            text-align: center;
        }
        .comparison-card ul li .no-check {
            color: rgba(255, 255, 255, 0.15);
        }
        .comparison-card .btn-glow {
            width: 100%;
            justify-content: center;
        }

        /* ===== Tier Highlights ===== */
        .tiers {
            background: var(--color-bg);
        }
        .tier-grid {
            display: grid;
            grid-template-columns: repeat(3, 1fr);
            gap: 24px;
        }
        .tier-card {
            padding: 2rem 1.8rem;
            border-radius: var(--radius-card);
            background: var(--color-card-bg);
            backdrop-filter: blur(14px);
            -webkit-backdrop-filter: blur(14px);
            border: 1px solid var(--color-border);
            transition: all var(--transition-base);
            text-align: center;
            position: relative;
        }
        .tier-card:hover {
            border-color: var(--color-border-hover);
            transform: translateY(-4px);
            box-shadow: var(--shadow-card-hover);
        }
        .tier-card.highlight-tier {
            border-color: rgba(123, 97, 255, 0.3);
            background: rgba(123, 97, 255, 0.06);
        }
        .tier-card .tier-icon {
            width: 56px;
            height: 56px;
            border-radius: 50%;
            background: linear-gradient(135deg, rgba(26, 107, 255, 0.2), rgba(123, 97, 255, 0.2));
            display: flex;
            align-items: center;
            justify-content: center;
            margin: 0 auto 16px;
            font-size: 1.6rem;
            color: var(--color-accent1);
        }
        .tier-card .tier-name {
            font-size: 1.3rem;
            font-weight: 600;
            color: var(--color-text-emphasis);
            margin-bottom: 6px;
        }
        .tier-card .tier-summary {
            font-size: 0.9rem;
            color: var(--color-text-secondary);
            margin-bottom: 16px;
        }
        .tier-card .tier-progress {
            height: 6px;
            background: rgba(255, 255, 255, 0.08);
            border-radius: 3px;
            overflow: hidden;
            margin-top: 12px;
        }
        .tier-card .tier-progress .fill {
            height: 100%;
            border-radius: 3px;
            background: linear-gradient(90deg, var(--color-brand), var(--color-accent1));
            transition: width 0.8s ease;
        }
        .tier-card .tier-progress .fill.accent2 {
            background: linear-gradient(90deg, var(--color-accent2), var(--color-brand));
        }

        .tier-connector {
            display: none;
        }

        /* ===== Exclusive Content ===== */
        .exclusive {
            background: var(--color-bg);
        }
        .exclusive-grid {
            display: grid;
            grid-template-columns: repeat(3, 1fr);
            gap: 24px;
        }
        .exclusive-card {
            border-radius: var(--radius-card);
            overflow: hidden;
            background: var(--color-card-bg);
            backdrop-filter: blur(12px);
            -webkit-backdrop-filter: blur(12px);
            border: 1px solid var(--color-border);
            transition: all var(--transition-base);
            position: relative;
        }
        .exclusive-card:hover {
            border-color: var(--color-border-hover);
            transform: translateY(-4px);
            box-shadow: var(--shadow-card-hover);
        }
        .exclusive-card .card-img {
            position: relative;
            overflow: hidden;
            aspect-ratio: 16 / 9;
        }
        .exclusive-card .card-img img {
            width: 100%;
            height: 100%;
            object-fit: cover;
            transition: transform 0.5s ease;
        }
        .exclusive-card:hover .card-img img {
            transform: scale(1.05);
        }
        .exclusive-card .card-img .lock-overlay {
            position: absolute;
            inset: 0;
            background: rgba(6, 14, 26, 0.55);
            display: flex;
            align-items: center;
            justify-content: center;
            font-size: 2.2rem;
            color: rgba(255, 255, 255, 0.8);
            backdrop-filter: blur(2px);
            -webkit-backdrop-filter: blur(2px);
        }
        .exclusive-card .card-img .member-tag {
            position: absolute;
            top: 12px;
            left: 12px;
            background: var(--color-accent2);
            color: #fff;
            font-size: 0.7rem;
            font-weight: 600;
            padding: 3px 12px;
            border-radius: 999px;
            letter-spacing: 0.02em;
            box-shadow: 0 2px 12px rgba(123, 97, 255, 0.3);
        }
        .exclusive-card .card-body {
            padding: 1.2rem 1.5rem 1.5rem;
        }
        .exclusive-card .card-body h3 {
            font-size: 1.15rem;
            font-weight: 600;
            color: var(--color-text-emphasis);
            margin-bottom: 6px;
        }
        .exclusive-card .card-body p {
            font-size: 0.875rem;
            color: var(--color-text-secondary);
            line-height: 1.5;
        }

        /* ===== FAQ ===== */
        .faq {
            background: var(--color-bg);
        }
        .faq-list {
            max-width: 800px;
            margin: 0 auto;
            display: flex;
            flex-direction: column;
            gap: 12px;
        }
        .faq-item {
            border-radius: var(--radius-card);
            background: var(--color-card-bg);
            backdrop-filter: blur(12px);
            -webkit-backdrop-filter: blur(12px);
            border: 1px solid var(--color-border);
            overflow: hidden;
            transition: all var(--transition-base);
        }
        .faq-item:hover {
            border-color: var(--color-border-hover);
        }
        .faq-item.open {
            border-color: rgba(26, 107, 255, 0.2);
        }
        .faq-question {
            display: flex;
            align-items: center;
            justify-content: space-between;
            padding: 1.2rem 1.5rem;
            cursor: pointer;
            font-size: 1rem;
            font-weight: 500;
            color: var(--color-text);
            background: none;
            border: none;
            width: 100%;
            text-align: left;
            gap: 12px;
            transition: color var(--transition-base);
        }
        .faq-question:hover {
            color: var(--color-text-emphasis);
        }
        .faq-question i {
            font-size: 1rem;
            color: var(--color-text-secondary);
            transition: transform var(--transition-base);
            flex-shrink: 0;
        }
        .faq-item.open .faq-question i {
            transform: rotate(180deg);
            color: var(--color-brand);
        }
        .faq-answer {
            max-height: 0;
            overflow: hidden;
            transition: max-height 0.4s ease, padding 0.3s ease;
            padding: 0 1.5rem;
            color: var(--color-text-secondary);
            font-size: 0.95rem;
            line-height: 1.7;
        }
        .faq-item.open .faq-answer {
            max-height: 400px;
            padding: 0 1.5rem 1.2rem;
        }

        /* ===== CTA Section ===== */
        .cta-section {
            background: linear-gradient(135deg, #060e1a 0%, #0b1a2e 50%, #0f2240 100%);
            text-align: center;
            padding: 5rem 0;
            position: relative;
            overflow: hidden;
        }
        .cta-section::before {
            content: '';
            position: absolute;
            top: 50%;
            left: 50%;
            transform: translate(-50%, -50%);
            width: 80%;
            height: 80%;
            background: radial-gradient(ellipse at center, rgba(26, 107, 255, 0.06) 0%, transparent 70%);
            pointer-events: none;
        }
        .cta-section .container {
            position: relative;
            z-index: 2;
        }
        .cta-section h2 {
            font-size: 2.4rem;
            font-weight: 600;
            color: var(--color-text-emphasis);
            margin-bottom: 0.8rem;
        }
        .cta-section p {
            font-size: 1.1rem;
            color: var(--color-text-secondary);
            max-width: 600px;
            margin: 0 auto 2rem;
        }

        /* ===== Latest News (CMS) ===== */
        .latest-news {
            background: var(--color-bg);
        }
        .news-list {
            display: flex;
            flex-direction: column;
            gap: 16px;
        }
        .news-card {
            display: flex;
            align-items: stretch;
            gap: 20px;
            padding: 1.2rem 1.5rem;
            border-radius: var(--radius-card);
            background: var(--color-card-bg);
            backdrop-filter: blur(12px);
            -webkit-backdrop-filter: blur(12px);
            border: 1px solid var(--color-border);
            transition: all var(--transition-base);
        }
        .news-card:hover {
            border-color: var(--color-border-hover);
            transform: translateX(4px);
            box-shadow: var(--shadow-card-hover);
        }
        .news-card .news-img {
            width: 160px;
            min-height: 100px;
            border-radius: var(--radius-inner);
            overflow: hidden;
            flex-shrink: 0;
            background: var(--color-primary-light);
        }
        .news-card .news-img img {
            width: 100%;
            height: 100%;
            object-fit: cover;
        }
        .news-card .news-body {
            flex: 1;
            display: flex;
            flex-direction: column;
            justify-content: center;
            min-width: 0;
        }
        .news-card .news-body h3 {
            font-size: 1.1rem;
            font-weight: 600;
            color: var(--color-text-emphasis);
            margin-bottom: 4px;
            line-height: 1.4;
            display: -webkit-box;
            -webkit-line-clamp: 2;
            -webkit-box-orient: vertical;
            overflow: hidden;
        }
        .news-card .news-body .news-meta {
            display: flex;
            align-items: center;
            gap: 12px;
            font-size: 0.8rem;
            color: var(--color-text-secondary);
            margin-bottom: 6px;
        }
        .news-card .news-body .news-meta .badge {
            font-size: 0.65rem;
            padding: 2px 10px;
        }
        .news-card .news-body .news-excerpt {
            font-size: 0.875rem;
            color: var(--color-text-secondary);
            display: -webkit-box;
            -webkit-line-clamp: 2;
            -webkit-box-orient: vertical;
            overflow: hidden;
            line-height: 1.5;
        }
        .news-card .news-link {
            color: var(--color-brand);
            font-size: 0.85rem;
            font-weight: 500;
            display: inline-flex;
            align-items: center;
            gap: 6px;
            margin-top: 8px;
            transition: gap var(--transition-base);
        }
        .news-card .news-link:hover {
            gap: 10px;
        }

        .news-empty {
            text-align: center;
            padding: 3rem 1rem;
            color: var(--color-text-secondary);
        }
        .news-empty i {
            font-size: 2.5rem;
            margin-bottom: 12px;
            opacity: 0.4;
        }
        .news-empty p {
            font-size: 1rem;
        }

        /* ===== Footer ===== */
        .site-footer {
            background: #060e1a;
            border-top: 2px solid transparent;
            border-image: linear-gradient(90deg, #0b1a2e, var(--color-brand)) 1;
            padding: 4rem 0 2rem;
        }
        .footer-grid {
            display: grid;
            grid-template-columns: 2fr 1fr 1fr 1fr;
            gap: 32px;
            margin-bottom: 2.5rem;
        }
        .footer-brand .nav-logo {
            font-size: 1.3rem;
            margin-bottom: 12px;
        }
        .footer-brand p {
            font-size: 0.875rem;
            color: var(--color-text-secondary);
            max-width: 320px;
            line-height: 1.6;
        }
        .footer-col h4 {
            font-size: 0.95rem;
            font-weight: 600;
            color: var(--color-text-emphasis);
            margin-bottom: 16px;
        }
        .footer-col a {
            display: block;
            font-size: 0.875rem;
            color: var(--color-text-secondary);
            padding: 4px 0;
            transition: color var(--transition-base);
        }
        .footer-col a:hover {
            color: var(--color-brand);
        }
        .footer-col .social-links {
            display: flex;
            gap: 12px;
            margin-top: 8px;
        }
        .footer-col .social-links a {
            width: 36px;
            height: 36px;
            border-radius: 50%;
            background: rgba(255, 255, 255, 0.05);
            display: flex;
            align-items: center;
            justify-content: center;
            color: var(--color-text-secondary);
            font-size: 1rem;
            transition: all var(--transition-base);
            padding: 0;
        }
        .footer-col .social-links a:hover {
            background: var(--color-brand);
            color: #fff;
            transform: scale(1.1);
        }
        .footer-bottom {
            border-top: 1px solid rgba(255, 255, 255, 0.05);
            padding-top: 1.5rem;
            display: flex;
            justify-content: space-between;
            align-items: center;
            flex-wrap: wrap;
            gap: 12px;
            font-size: 0.8rem;
            color: var(--color-text-secondary);
        }
        .footer-bottom a {
            color: var(--color-text-secondary);
        }
        .footer-bottom a:hover {
            color: var(--color-brand);
        }

        /* ===== Responsive ===== */
        @media (max-width: 1024px) {
            :root {
                --padding-container: 20px;
                --gap-section: 4rem;
                --gap-section-inner: 2rem;
            }
            .hero h1 {
                font-size: 2.5rem;
            }
            .hero {
                padding: 130px 0 80px;
                min-height: auto;
            }
            .comparison-grid {
                grid-template-columns: 1fr 1fr 1fr;
                gap: 16px;
            }
            .tier-grid {
                grid-template-columns: repeat(3, 1fr);
                gap: 16px;
            }
            .exclusive-grid {
                grid-template-columns: repeat(3, 1fr);
                gap: 16px;
            }
            .footer-grid {
                grid-template-columns: 1fr 1fr;
                gap: 24px;
            }
            .nav-center {
                gap: 1.2rem;
            }
            .nav-search {
                min-width: 120px;
            }
            .section-title {
                font-size: 1.8rem;
            }
        }

        @media (max-width: 768px) {
            :root {
                --padding-container: 16px;
                --gap-section: 3rem;
                --gap-section-inner: 1.5rem;
            }
            .site-header {
                height: 64px;
            }
            .nav-center {
                display: none;
            }
            .nav-right .nav-search,
            .nav-right .nav-btn-login,
            .nav-right .nav-btn-cta {
                display: none;
            }
            .nav-hamburger {
                display: flex;
            }
            .mobile-nav.open {
                display: flex;
            }

            .hero {
                padding: 100px 0 60px;
                min-height: auto;
            }
            .hero h1 {
                font-size: 1.8rem;
            }
            .hero-sub {
                font-size: 1rem;
            }
            .hero-actions {
                flex-direction: column;
                width: 100%;
            }
            .hero-actions .btn-glow {
                width: 100%;
                justify-content: center;
            }

            .comparison-grid {
                grid-template-columns: 1fr;
                gap: 16px;
                max-width: 480px;
                margin: 0 auto;
            }
            .comparison-card {
                padding: 1.5rem 1.2rem;
            }
            .comparison-card .plan-price {
                font-size: 2rem;
            }

            .tier-grid {
                grid-template-columns: 1fr;
                gap: 16px;
                max-width: 420px;
                margin: 0 auto;
            }

            .exclusive-grid {
                grid-template-columns: 1fr;
                gap: 16px;
                max-width: 480px;
                margin: 0 auto;
            }

            .faq-list {
                max-width: 100%;
            }
            .faq-question {
                font-size: 0.95rem;
                padding: 1rem 1.2rem;
            }
            .faq-answer {
                font-size: 0.9rem;
            }
            .faq-item.open .faq-answer {
                padding: 0 1.2rem 1rem;
            }

            .cta-section h2 {
                font-size: 1.6rem;
            }
            .cta-section p {
                font-size: 1rem;
            }
            .cta-section .btn-glow-large {
                padding: 14px 36px;
                font-size: 1rem;
                width: 100%;
                max-width: 320px;
                margin: 0 auto;
            }

            .news-card {
                flex-direction: column;
                padding: 1rem 1.2rem;
            }
            .news-card .news-img {
                width: 100%;
                height: 120px;
            }
            .news-card .news-body h3 {
                font-size: 1rem;
            }

            .footer-grid {
                grid-template-columns: 1fr;
                gap: 24px;
                text-align: center;
            }
            .footer-brand p {
                margin: 0 auto;
            }
            .footer-col .social-links {
                justify-content: center;
            }
            .footer-bottom {
                flex-direction: column;
                text-align: center;
            }

            .section-title {
                font-size: 1.5rem;
            }
            .section-subtitle {
                font-size: 1rem;
            }
            .grid-3,
            .grid-4,
            .grid-2 {
                grid-template-columns: 1fr;
            }
        }

        @media (max-width: 520px) {
            .hero h1 {
                font-size: 1.5rem;
            }
            .hero-sub {
                font-size: 0.9rem;
            }
            .hero-actions .btn-glow {
                padding: 14px 24px;
                font-size: 0.95rem;
            }
            .comparison-card .plan-price {
                font-size: 1.6rem;
            }
            .tier-card .tier-name {
                font-size: 1.1rem;
            }
            .exclusive-card .card-body h3 {
                font-size: 1rem;
            }
            .cta-section h2 {
                font-size: 1.3rem;
            }
        }

        /* ===== Animations ===== */
        @keyframes fadeInUp {
            from {
                opacity: 0;
                transform: translateY(30px);
            }
            to {
                opacity: 1;
                transform: translateY(0);
            }
        }
        .animate-in {
            animation: fadeInUp 0.6s ease forwards;
        }
        .animate-in-delay-1 {
            animation-delay: 0.1s;
        }
        .animate-in-delay-2 {
            animation-delay: 0.2s;
        }
        .animate-in-delay-3 {
            animation-delay: 0.3s;
        }

        /* ===== Misc ===== */
        .text-center {
            text-align: center;
        }
        .mt-1 {
            margin-top: 1rem;
        }
        .mt-2 {
            margin-top: 2rem;
        }
        .mb-1 {
            margin-bottom: 1rem;
        }
        .mb-2 {
            margin-bottom: 2rem;
        }
        .gap-1 {
            gap: 1rem;
        }

        /* Back to top (optional) */
        .back-top {
            position: fixed;
            bottom: 32px;
            right: 32px;
            width: 44px;
            height: 44px;
            border-radius: 50%;
            background: var(--color-brand);
            color: #fff;
            display: flex;
            align-items: center;
            justify-content: center;
            font-size: 1.2rem;
            box-shadow: 0 4px 20px rgba(26, 107, 255, 0.3);
            z-index: 900;
            transition: all var(--transition-base);
            opacity: 0;
            pointer-events: none;
        }
        .back-top.visible {
            opacity: 1;
            pointer-events: auto;
        }
        .back-top:hover {
            transform: translateY(-4px);
            box-shadow: 0 6px 30px rgba(26, 107, 255, 0.5);
            color: #fff;
        }

/* roulang page: article */
/* ===== Design Variables ===== */
        :root {
            --primary: #0b1a2e;
            --primary-light: #0f2240;
            --brand: #1a6bff;
            --brand-dark: #0f4dcc;
            --accent1: #00d4ff;
            --accent2: #7b61ff;
            --bg-main: #060e1a;
            --text-main: #e8edf5;
            --text-muted: #8a9bb5;
            --text-strong: #ffffff;
            --border-subtle: rgba(255,255,255,0.06);
            --border-hover: rgba(255,255,255,0.12);
            --card-bg: rgba(255,255,255,0.04);
            --card-bg-hover: rgba(255,255,255,0.08);
            --glow-brand: rgba(26,107,255,0.3);
            --glow-brand-strong: rgba(26,107,255,0.5);
            --glow-accent2: rgba(123,97,255,0.3);
            --radius-card: 12px;
            --radius-inner: 8px;
            --radius-sm: 6px;
            --shadow-card: 0 8px 32px rgba(0,0,0,0.3);
            --shadow-card-hover: 0 12px 48px rgba(0,0,0,0.5);
            --transition: 0.3s cubic-bezier(0.4,0,0.2,1);
            --max-width: 1280px;
            --font-family: 'PingFang SC','Microsoft YaHei','Helvetica Neue',Arial,sans-serif;
        }

        /* ===== Reset & Base ===== */
        *, *::before, *::after { box-sizing: border-box; margin: 0; padding: 0; }
        html { scroll-behavior: smooth; -webkit-font-smoothing: antialiased; }
        body {
            font-family: var(--font-family);
            font-size: 1rem;
            line-height: 1.7;
            color: var(--text-main);
            background: var(--bg-main);
            min-height: 100vh;
            display: flex;
            flex-direction: column;
        }
        a { color: var(--brand); text-decoration: none; transition: color var(--transition); }
        a:hover { color: var(--accent1); }
        img { max-width: 100%; height: auto; display: block; border-radius: var(--radius-inner); }
        button, input, textarea { font-family: inherit; font-size: inherit; }
        ul, ol { list-style: none; }
        h1, h2, h3, h4, h5, h6 { font-weight: 600; line-height: 1.3; color: var(--text-strong); }

        /* ===== Container ===== */
        .container {
            max-width: var(--max-width);
            margin: 0 auto;
            padding: 0 24px;
        }

        /* ===== Header / Nav ===== */
        .site-header {
            position: sticky;
            top: 0;
            z-index: 1000;
            background: rgba(6,14,26,0.92);
            backdrop-filter: blur(16px);
            border-bottom: 1px solid var(--border-subtle);
        }
        .nav-inner {
            display: flex;
            align-items: center;
            justify-content: space-between;
            height: 72px;
            gap: 24px;
        }
        .nav-logo {
            display: flex;
            align-items: center;
            gap: 10px;
            font-size: 1.25rem;
            font-weight: 600;
            color: var(--text-strong);
            white-space: nowrap;
        }
        .nav-logo:hover { color: var(--text-strong); opacity: 0.9; }
        .nav-logo svg { flex-shrink: 0; }
        .nav-center {
            display: flex;
            align-items: center;
            gap: 2rem;
        }
        .nav-center a {
            position: relative;
            font-size: 0.95rem;
            font-weight: 500;
            color: var(--text-muted);
            padding: 4px 0;
            transition: color var(--transition);
        }
        .nav-center a::after {
            content: '';
            position: absolute;
            bottom: -2px;
            left: 0;
            width: 0;
            height: 2px;
            background: var(--brand);
            border-radius: 2px;
            transition: width var(--transition);
            box-shadow: 0 0 8px var(--glow-brand);
        }
        .nav-center a:hover { color: var(--text-main); }
        .nav-center a:hover::after { width: 100%; }
        .nav-center a.active { color: var(--text-strong); }
        .nav-center a.active::after { width: 100%; background: var(--accent1); box-shadow: 0 0 12px rgba(0,212,255,0.4); }
        .nav-right {
            display: flex;
            align-items: center;
            gap: 16px;
            flex-shrink: 0;
        }
        .nav-search {
            display: flex;
            align-items: center;
            background: rgba(255,255,255,0.06);
            border: 1px solid var(--border-subtle);
            border-radius: 20px;
            padding: 6px 16px;
            gap: 8px;
            transition: border var(--transition), background var(--transition);
        }
        .nav-search:focus-within {
            border-color: var(--brand);
            background: rgba(255,255,255,0.08);
            box-shadow: 0 0 12px var(--glow-brand);
        }
        .nav-search i { color: var(--text-muted); font-size: 0.9rem; }
        .nav-search input {
            background: none;
            border: none;
            outline: none;
            color: var(--text-main);
            font-size: 0.9rem;
            width: 140px;
            transition: width var(--transition);
        }
        .nav-search input::placeholder { color: var(--text-muted); }
        .nav-search input:focus { width: 180px; }
        .nav-btn {
            display: inline-flex;
            align-items: center;
            justify-content: center;
            padding: 8px 20px;
            border-radius: var(--radius-sm);
            font-weight: 600;
            font-size: 0.9rem;
            cursor: pointer;
            transition: all var(--transition);
            border: none;
            white-space: nowrap;
        }
        .nav-btn-outline {
            background: transparent;
            border: 1.5px solid rgba(255,255,255,0.15);
            color: var(--text-main);
        }
        .nav-btn-outline:hover { border-color: var(--brand); color: var(--text-strong); box-shadow: 0 0 16px var(--glow-brand); }
        .nav-btn-ghost {
            background: transparent;
            color: var(--text-muted);
            padding: 8px 12px;
        }
        .nav-btn-ghost:hover { color: var(--text-main); }
        .nav-btn-primary {
            background: linear-gradient(135deg, var(--accent2), #5a3fd4);
            color: var(--text-strong);
            box-shadow: 0 4px 20px var(--glow-accent2);
        }
        .nav-btn-primary:hover { box-shadow: 0 6px 30px rgba(123,97,255,0.5); transform: scale(1.02); }
        .nav-btn-primary:active { transform: scale(0.98); }
        .hamburger { display: none; flex-direction: column; gap: 5px; cursor: pointer; padding: 4px; background: none; border: none; }
        .hamburger span { display: block; width: 24px; height: 2px; background: var(--text-main); border-radius: 2px; transition: var(--transition); }

        /* ===== Breadcrumb ===== */
        .breadcrumb {
            padding: 24px 0 8px;
            font-size: 0.875rem;
            color: var(--text-muted);
        }
        .breadcrumb a { color: var(--text-muted); }
        .breadcrumb a:hover { color: var(--brand); }
        .breadcrumb span { color: var(--text-muted); margin: 0 6px; }

        /* ===== Article Header ===== */
        .article-header {
            padding: 32px 0 24px;
            border-bottom: 1px solid var(--border-subtle);
        }
        .article-header .article-meta {
            display: flex;
            flex-wrap: wrap;
            gap: 16px 24px;
            align-items: center;
            margin-top: 16px;
            font-size: 0.9rem;
            color: var(--text-muted);
        }
        .article-header .article-meta i { margin-right: 6px; }
        .article-header .article-meta .cat-tag {
            display: inline-block;
            padding: 2px 12px;
            background: rgba(123,97,255,0.15);
            color: var(--accent2);
            border-radius: 20px;
            font-size: 0.8rem;
            font-weight: 500;
        }
        .article-header h1 {
            font-size: 2.5rem;
            font-weight: 700;
            line-height: 1.25;
            letter-spacing: -0.01em;
            background: linear-gradient(135deg, #e8edf5 0%, #1a6bff 100%);
            -webkit-background-clip: text;
            -webkit-text-fill-color: transparent;
            background-clip: text;
        }

        /* ===== Article Body ===== */
        .article-body-wrap {
            max-width: 800px;
            margin: 0 auto;
            padding: 40px 0 48px;
        }
        .article-body {
            font-size: 1.05rem;
            line-height: 1.8;
            color: var(--text-main);
        }
        .article-body p { margin-bottom: 1.5rem; }
        .article-body h2 { font-size: 1.75rem; margin: 2.5rem 0 1rem; color: var(--text-strong); }
        .article-body h3 { font-size: 1.35rem; margin: 2rem 0 0.75rem; color: var(--text-strong); }
        .article-body blockquote {
            border-left: 4px solid var(--brand);
            background: rgba(255,255,255,0.04);
            backdrop-filter: blur(12px);
            padding: 1.25rem 1.75rem;
            margin: 1.5rem 0;
            border-radius: 0 var(--radius-inner) var(--radius-inner) 0;
            color: var(--text-muted);
            font-style: italic;
        }
        .article-body code {
            background: rgba(0,0,0,0.4);
            padding: 2px 8px;
            border-radius: 4px;
            font-family: 'SF Mono','Fira Code','Consolas',monospace;
            font-size: 0.9em;
            color: var(--accent1);
        }
        .article-body pre {
            background: rgba(0,0,0,0.5);
            border-radius: var(--radius-inner);
            padding: 1.25rem 1.5rem;
            overflow-x: auto;
            margin: 1.5rem 0;
            border: 1px solid var(--border-subtle);
        }
        .article-body pre code { background: none; padding: 0; color: inherit; font-size: 0.9rem; }
        .article-body img {
            border-radius: var(--radius-card);
            margin: 2rem auto;
            box-shadow: var(--shadow-card);
        }
        .article-body ul, .article-body ol {
            margin: 1.25rem 0;
            padding-left: 1.5rem;
        }
        .article-body ul li { list-style: disc; margin-bottom: 0.5rem; }
        .article-body ol li { list-style: decimal; margin-bottom: 0.5rem; }
        .article-body a { color: var(--brand); text-decoration: underline; text-underline-offset: 2px; }
        .article-body a:hover { color: var(--accent1); }

        /* ===== Not Found ===== */
        .not-found-box {
            text-align: center;
            padding: 80px 24px;
            max-width: 600px;
            margin: 0 auto;
        }
        .not-found-box i { font-size: 4rem; color: var(--text-muted); margin-bottom: 24px; opacity: 0.5; }
        .not-found-box h2 { font-size: 1.75rem; margin-bottom: 12px; }
        .not-found-box p { color: var(--text-muted); margin-bottom: 24px; }
        .not-found-box a { color: var(--brand); font-weight: 500; }

        /* ===== Related Posts ===== */
        .related-section {
            padding: 48px 0 32px;
            border-top: 1px solid var(--border-subtle);
        }
        .related-section h2 {
            font-size: 1.75rem;
            margin-bottom: 28px;
            color: var(--text-strong);
        }
        .related-grid {
            display: grid;
            grid-template-columns: repeat(3, 1fr);
            gap: 24px;
        }
        .related-card {
            background: var(--card-bg);
            backdrop-filter: blur(12px);
            border: 1px solid var(--border-subtle);
            border-radius: var(--radius-card);
            overflow: hidden;
            transition: all var(--transition);
            box-shadow: var(--shadow-card);
        }
        .related-card:hover { border-color: var(--border-hover); box-shadow: var(--shadow-card-hover); transform: translateY(-3px); }
        .related-card img { width: 100%; height: 160px; object-fit: cover; border-radius: 0; }
        .related-card .card-body { padding: 16px 20px 20px; }
        .related-card .card-body h3 { font-size: 1.05rem; font-weight: 600; margin-bottom: 8px; color: var(--text-strong); line-height: 1.4; }
        .related-card .card-body p { font-size: 0.875rem; color: var(--text-muted); display: -webkit-box; -webkit-line-clamp: 2; -webkit-box-orient: vertical; overflow: hidden; }
        .related-card .card-body .meta { font-size: 0.8rem; color: var(--text-muted); margin-top: 12px; display: flex; gap: 12px; align-items: center; }

        /* ===== Back Link ===== */
        .back-link-wrap { padding: 16px 0 48px; }
        .back-link-wrap a { color: var(--text-muted); font-size: 0.95rem; }
        .back-link-wrap a:hover { color: var(--brand); }
        .back-link-wrap a i { margin-right: 6px; }

        /* ===== Footer ===== */
        .site-footer {
            background: #060e1a;
            border-top: 2px solid transparent;
            border-image: linear-gradient(90deg, #0b1a2e, #1a6bff) 1;
            padding: 64px 0 32px;
            margin-top: auto;
        }
        .footer-grid {
            display: grid;
            grid-template-columns: 2fr 1fr 1fr 1.5fr;
            gap: 40px;
        }
        .footer-brand p { font-size: 0.9rem; color: var(--text-muted); margin-top: 16px; line-height: 1.7; max-width: 360px; }
        .footer-col h4 { font-size: 1rem; font-weight: 600; color: var(--text-strong); margin-bottom: 16px; }
        .footer-col a { display: block; font-size: 0.9rem; color: var(--text-muted); margin-bottom: 10px; transition: color var(--transition); }
        .footer-col a:hover { color: var(--brand); }
        .social-links { display: flex; gap: 16px; margin-top: 16px; }
        .social-links a { font-size: 1.3rem; color: var(--text-muted); margin-bottom: 0; }
        .social-links a:hover { color: var(--brand); }
        .footer-bottom { border-top: 1px solid var(--border-subtle); margin-top: 40px; padding-top: 24px; text-align: center; font-size: 0.85rem; color: var(--text-muted); }
        .footer-bottom a { color: var(--text-muted); }
        .footer-bottom a:hover { color: var(--brand); }

        /* ===== Responsive ===== */
        @media (max-width: 1024px) {
            .related-grid { grid-template-columns: repeat(2, 1fr); }
            .footer-grid { grid-template-columns: 1fr 1fr; gap: 32px; }
            .article-header h1 { font-size: 2rem; }
        }
        @media (max-width: 768px) {
            .container { padding: 0 16px; }
            .nav-center { display: none; }
            .nav-right .nav-search { display: none; }
            .nav-right .nav-btn-outline { display: none; }
            .hamburger { display: flex; }
            .nav-inner { height: 64px; }
            .article-header h1 { font-size: 1.6rem; }
            .article-body-wrap { padding: 24px 0 32px; }
            .article-body { font-size: 1rem; }
            .related-grid { grid-template-columns: 1fr; gap: 16px; }
            .footer-grid { grid-template-columns: 1fr; gap: 24px; }
            .footer-brand p { max-width: 100%; }
            .breadcrumb { font-size: 0.8rem; }
            .article-header .article-meta { gap: 12px; font-size: 0.85rem; }
        }
        @media (max-width: 520px) {
            .article-header h1 { font-size: 1.35rem; }
            .article-body blockquote { padding: 1rem 1.25rem; }
            .related-card img { height: 140px; }
        }

        /* ===== Mobile Drawer ===== */
        .mobile-drawer {
            display: none;
            position: fixed;
            top: 0;
            left: 0;
            width: 100%;
            height: 100%;
            background: rgba(6,14,26,0.98);
            backdrop-filter: blur(24px);
            z-index: 2000;
            flex-direction: column;
            align-items: center;
            justify-content: center;
            gap: 32px;
            opacity: 0;
            pointer-events: none;
            transition: opacity 0.4s ease;
        }
        .mobile-drawer.open { display: flex; opacity: 1; pointer-events: auto; }
        .mobile-drawer a { font-size: 1.4rem; font-weight: 500; color: var(--text-muted); transition: color var(--transition); }
        .mobile-drawer a:hover, .mobile-drawer a.active { color: var(--text-strong); }
        .mobile-drawer .close-btn {
            position: absolute;
            top: 20px;
            right: 24px;
            background: none;
            border: none;
            font-size: 2rem;
            color: var(--text-main);
            cursor: pointer;
        }
        .mobile-drawer .drawer-search {
            display: flex;
            align-items: center;
            background: rgba(255,255,255,0.08);
            border: 1px solid var(--border-subtle);
            border-radius: 24px;
            padding: 10px 20px;
            width: 80%;
            max-width: 360px;
            gap: 10px;
        }
        .mobile-drawer .drawer-search i { color: var(--text-muted); }
        .mobile-drawer .drawer-search input { background: none; border: none; outline: none; color: var(--text-main); width: 100%; font-size: 1rem; }
        .mobile-drawer .drawer-search input::placeholder { color: var(--text-muted); }
        .mobile-drawer .drawer-btn {
            margin-top: 8px;
            padding: 12px 40px;
            border-radius: var(--radius-sm);
            background: linear-gradient(135deg, var(--accent2), #5a3fd4);
            color: var(--text-strong);
            font-weight: 600;
            font-size: 1.05rem;
            border: none;
            cursor: pointer;
            box-shadow: 0 4px 20px var(--glow-accent2);
            transition: all var(--transition);
        }
        .mobile-drawer .drawer-btn:hover { box-shadow: 0 6px 30px rgba(123,97,255,0.5); transform: scale(1.02); }

/* roulang page: category1 */
/* ===== Design Variables ===== */
        :root {
            --primary: #0b1a2e;
            --primary-light: #0f2240;
            --brand: #1a6bff;
            --accent1: #00d4ff;
            --accent2: #7b61ff;
            --bg: #060e1a;
            --card-bg: rgba(255, 255, 255, 0.04);
            --card-border: rgba(255, 255, 255, 0.06);
            --card-border-hover: rgba(255, 255, 255, 0.12);
            --text-primary: #e8edf5;
            --text-secondary: #8a9bb5;
            --text-emphasis: #ffffff;
            --radius-sm: 6px;
            --radius-md: 8px;
            --radius-lg: 12px;
            --shadow-card: 0 8px 32px rgba(0, 0, 0, 0.3);
            --shadow-card-hover: 0 12px 48px rgba(0, 0, 0, 0.5);
            --transition: all 0.3s ease;
            --container-max: 1280px;
            --container-padding: 24px;
            --font-family: 'PingFang SC', 'Microsoft YaHei', 'Helvetica Neue', Arial, sans-serif;
        }

        /* ===== Reset & Base ===== */
        *,
        *::before,
        *::after {
            box-sizing: border-box;
            margin: 0;
            padding: 0;
        }

        html {
            scroll-behavior: smooth;
        }

        body {
            font-family: var(--font-family);
            background: var(--bg);
            color: var(--text-primary);
            line-height: 1.7;
            font-size: 16px;
            -webkit-font-smoothing: antialiased;
            -moz-osx-font-smoothing: grayscale;
        }

        a {
            color: var(--text-primary);
            text-decoration: none;
            transition: var(--transition);
        }
        a:hover {
            color: var(--brand);
        }

        img {
            max-width: 100%;
            height: auto;
            display: block;
            border-radius: var(--radius-md);
        }

        button,
        input,
        textarea {
            font-family: inherit;
            font-size: inherit;
            outline: none;
            border: none;
        }

        ul,
        ol {
            list-style: none;
        }

        /* ===== Container ===== */
        .container {
            max-width: var(--container-max);
            margin: 0 auto;
            padding: 0 var(--container-padding);
        }

        /* ===== Header & Navigation ===== */
        .site-header {
            position: fixed;
            top: 0;
            left: 0;
            width: 100%;
            z-index: 1000;
            background: rgba(6, 14, 26, 0.92);
            backdrop-filter: blur(20px);
            -webkit-backdrop-filter: blur(20px);
            border-bottom: 1px solid rgba(255, 255, 255, 0.06);
            height: 72px;
            display: flex;
            align-items: center;
        }

        .site-header .container {
            display: flex;
            align-items: center;
            justify-content: space-between;
            width: 100%;
        }

        .nav-logo {
            display: flex;
            align-items: center;
            gap: 10px;
            font-size: 1.4rem;
            font-weight: 600;
            color: var(--text-emphasis);
            letter-spacing: -0.02em;
            flex-shrink: 0;
        }
        .nav-logo:hover {
            color: var(--text-emphasis);
        }
        .nav-logo svg {
            flex-shrink: 0;
        }

        .nav-center {
            display: flex;
            align-items: center;
            gap: 2rem;
        }
        .nav-center a {
            font-size: 0.95rem;
            font-weight: 500;
            color: var(--text-secondary);
            padding: 0.25rem 0;
            position: relative;
            transition: var(--transition);
        }
        .nav-center a::after {
            content: '';
            position: absolute;
            bottom: -2px;
            left: 0;
            width: 0;
            height: 2px;
            background: var(--brand);
            border-radius: 1px;
            transition: var(--transition);
            box-shadow: 0 0 10px rgba(26, 107, 255, 0.4);
        }
        .nav-center a:hover::after,
        .nav-center a.active::after {
            width: 100%;
        }
        .nav-center a:hover {
            color: var(--text-primary);
        }
        .nav-center a.active {
            color: var(--text-emphasis);
        }

        .nav-right {
            display: flex;
            align-items: center;
            gap: 1rem;
            flex-shrink: 0;
        }

        .search-box {
            display: flex;
            align-items: center;
            background: rgba(255, 255, 255, 0.06);
            border: 1px solid rgba(255, 255, 255, 0.1);
            border-radius: 20px;
            padding: 6px 16px;
            gap: 8px;
            transition: var(--transition);
        }
        .search-box:focus-within {
            border-color: var(--brand);
            box-shadow: 0 0 16px rgba(26, 107, 255, 0.15);
        }
        .search-box i {
            color: var(--text-secondary);
            font-size: 0.9rem;
        }
        .search-box input {
            background: transparent;
            border: none;
            color: var(--text-primary);
            font-size: 0.85rem;
            width: 120px;
            transition: var(--transition);
        }
        .search-box input::placeholder {
            color: var(--text-secondary);
        }
        .search-box input:focus {
            width: 160px;
        }

        .btn-login {
            background: transparent;
            border: 1.5px solid rgba(255, 255, 255, 0.15);
            color: var(--text-primary);
            padding: 8px 20px;
            border-radius: var(--radius-sm);
            font-weight: 500;
            font-size: 0.9rem;
            cursor: pointer;
            transition: var(--transition);
        }
        .btn-login:hover {
            border-color: var(--brand);
            color: var(--brand);
            background: rgba(26, 107, 255, 0.06);
        }

        .btn-cta-nav {
            background: linear-gradient(135deg, var(--accent2), #5a3fd4);
            color: #fff;
            padding: 8px 22px;
            border-radius: var(--radius-sm);
            font-weight: 600;
            font-size: 0.9rem;
            cursor: pointer;
            border: none;
            transition: var(--transition);
            box-shadow: 0 4px 20px rgba(123, 97, 255, 0.3);
        }
        .btn-cta-nav:hover {
            transform: scale(1.02);
            box-shadow: 0 6px 30px rgba(123, 97, 255, 0.5);
        }

        /* Hamburger */
        .hamburger {
            display: none;
            flex-direction: column;
            gap: 5px;
            cursor: pointer;
            background: none;
            border: none;
            padding: 4px;
        }
        .hamburger span {
            display: block;
            width: 26px;
            height: 2px;
            background: var(--text-primary);
            border-radius: 2px;
            transition: var(--transition);
        }

        /* Mobile Nav */
        .mobile-nav {
            display: none;
            position: fixed;
            top: 72px;
            left: 0;
            width: 100%;
            background: rgba(6, 14, 26, 0.98);
            backdrop-filter: blur(20px);
            padding: 1.5rem 2rem;
            border-bottom: 1px solid rgba(255, 255, 255, 0.06);
            z-index: 999;
            flex-direction: column;
            gap: 1rem;
        }
        .mobile-nav.open {
            display: flex;
        }
        .mobile-nav a {
            font-size: 1.1rem;
            font-weight: 500;
            color: var(--text-secondary);
            padding: 0.5rem 0;
            border-bottom: 1px solid rgba(255, 255, 255, 0.04);
        }
        .mobile-nav a.active {
            color: var(--text-emphasis);
        }
        .mobile-nav a:last-child {
            border-bottom: none;
        }
        .mobile-nav .mobile-cta {
            margin-top: 0.5rem;
        }

        /* ===== Hero ===== */
        .category-hero {
            padding: 140px 0 80px;
            background: linear-gradient(135deg, #060e1a 0%, #0b1a2e 50%, #0f2240 100%);
            position: relative;
            overflow: hidden;
            min-height: 360px;
            display: flex;
            align-items: center;
        }
        .category-hero::before {
            content: '';
            position: absolute;
            inset: 0;
            background: url('/assets/images/backpic/back-1.png') center center / cover no-repeat;
            opacity: 0.12;
            pointer-events: none;
        }
        .category-hero::after {
            content: '';
            position: absolute;
            top: -40%;
            right: -10%;
            width: 500px;
            height: 500px;
            background: radial-gradient(circle, rgba(26, 107, 255, 0.08) 0%, transparent 70%);
            pointer-events: none;
        }
        .category-hero .container {
            position: relative;
            z-index: 1;
            text-align: center;
        }
        .category-hero h1 {
            font-size: 3.2rem;
            font-weight: 700;
            letter-spacing: -0.02em;
            background: linear-gradient(135deg, #e8edf5 0%, #1a6bff 100%);
            -webkit-background-clip: text;
            -webkit-text-fill-color: transparent;
            background-clip: text;
            margin-bottom: 1.2rem;
        }
        .category-hero .hero-desc {
            max-width: 800px;
            margin: 0 auto;
            font-size: 1.15rem;
            color: var(--text-secondary);
            line-height: 1.8;
            font-weight: 300;
            letter-spacing: 0.02em;
        }

        /* ===== Section Shared ===== */
        section {
            padding: 5rem 0;
        }
        .section-title {
            font-size: 2.25rem;
            font-weight: 600;
            letter-spacing: -0.01em;
            color: var(--text-primary);
            margin-bottom: 1rem;
            text-align: center;
        }
        .section-sub {
            text-align: center;
            color: var(--text-secondary);
            font-size: 1.05rem;
            max-width: 700px;
            margin: 0 auto 3rem;
        }

        /* ===== Card Base ===== */
        .glass-card {
            background: var(--card-bg);
            backdrop-filter: blur(12px);
            -webkit-backdrop-filter: blur(12px);
            border: 1px solid var(--card-border);
            border-radius: var(--radius-lg);
            padding: 1.5rem;
            box-shadow: var(--shadow-card);
            transition: var(--transition);
        }
        .glass-card:hover {
            border-color: var(--card-border-hover);
            box-shadow: var(--shadow-card-hover);
            transform: translateY(-2px);
        }

        /* ===== Value Cards ===== */
        .value-grid {
            display: grid;
            grid-template-columns: repeat(3, 1fr);
            gap: 1.5rem;
        }
        .value-card {
            text-align: center;
            padding: 2.5rem 1.5rem;
        }
        .value-card .icon-wrap {
            width: 64px;
            height: 64px;
            margin: 0 auto 1.2rem;
            border-radius: 50%;
            background: rgba(26, 107, 255, 0.1);
            display: flex;
            align-items: center;
            justify-content: center;
            font-size: 1.8rem;
            color: var(--brand);
            transition: var(--transition);
        }
        .value-card:hover .icon-wrap {
            background: rgba(26, 107, 255, 0.2);
            transform: scale(1.05);
        }
        .value-card h3 {
            font-size: 1.3rem;
            font-weight: 600;
            margin-bottom: 0.6rem;
        }
        .value-card p {
            font-size: 0.95rem;
            color: var(--text-secondary);
            line-height: 1.7;
        }

        /* ===== Content Preview ===== */
        .preview-grid {
            display: grid;
            grid-template-columns: repeat(3, 1fr);
            gap: 1.5rem;
        }
        .preview-card {
            overflow: hidden;
            padding: 0;
            background: var(--card-bg);
            backdrop-filter: blur(12px);
            -webkit-backdrop-filter: blur(12px);
            border: 1px solid var(--card-border);
            border-radius: var(--radius-lg);
            box-shadow: var(--shadow-card);
            transition: var(--transition);
        }
        .preview-card:hover {
            border-color: var(--card-border-hover);
            box-shadow: var(--shadow-card-hover);
            transform: translateY(-2px);
        }
        .preview-card .card-img {
            width: 100%;
            height: 180px;
            object-fit: cover;
            border-radius: var(--radius-lg) var(--radius-lg) 0 0;
            display: block;
        }
        .preview-card .card-body {
            padding: 1.2rem 1.5rem 1.5rem;
        }
        .preview-card .tag {
            display: inline-block;
            padding: 2px 12px;
            border-radius: 20px;
            background: rgba(123, 97, 255, 0.15);
            color: var(--accent2);
            font-size: 0.75rem;
            font-weight: 500;
            margin-bottom: 0.5rem;
        }
        .preview-card h3 {
            font-size: 1.15rem;
            font-weight: 600;
            margin-bottom: 0.4rem;
            color: var(--text-primary);
        }
        .preview-card p {
            font-size: 0.9rem;
            color: var(--text-secondary);
            line-height: 1.6;
            display: -webkit-box;
            -webkit-line-clamp: 2;
            -webkit-box-orient: vertical;
            overflow: hidden;
        }
        .preview-card .card-meta {
            display: flex;
            align-items: center;
            justify-content: space-between;
            margin-top: 0.8rem;
            font-size: 0.8rem;
            color: var(--text-secondary);
        }
        .preview-card .card-meta a {
            color: var(--brand);
            font-weight: 500;
            font-size: 0.85rem;
        }
        .preview-card .card-meta a i {
            margin-left: 4px;
            font-size: 0.75rem;
        }

        /* ===== Feature Tabs ===== */
        .feature-section {
            background: linear-gradient(180deg, #060e1a 0%, #0b1a2e 100%);
        }
        .feature-grid {
            display: grid;
            grid-template-columns: repeat(2, 1fr);
            gap: 2rem;
            align-items: center;
        }
        .feature-image {
            border-radius: var(--radius-lg);
            overflow: hidden;
            box-shadow: var(--shadow-card);
        }
        .feature-image img {
            width: 100%;
            display: block;
        }
        .feature-content h2 {
            font-size: 2rem;
            font-weight: 600;
            margin-bottom: 1rem;
            letter-spacing: -0.01em;
        }
        .feature-content ul {
            display: flex;
            flex-direction: column;
            gap: 0.8rem;
        }
        .feature-content ul li {
            display: flex;
            align-items: flex-start;
            gap: 0.8rem;
            font-size: 1rem;
            color: var(--text-secondary);
        }
        .feature-content ul li i {
            color: var(--brand);
            font-size: 1.1rem;
            margin-top: 0.2rem;
            flex-shrink: 0;
        }

        /* ===== Timeline / Process ===== */
        .timeline-section {
            background: #060e1a;
        }
        .timeline-grid {
            display: grid;
            grid-template-columns: repeat(4, 1fr);
            gap: 1.5rem;
            margin-top: 2rem;
        }
        .timeline-step {
            text-align: center;
            padding: 2rem 1rem;
            position: relative;
        }
        .timeline-step .step-num {
            width: 44px;
            height: 44px;
            border-radius: 50%;
            background: linear-gradient(135deg, var(--brand), var(--accent1));
            display: flex;
            align-items: center;
            justify-content: center;
            font-size: 1.2rem;
            font-weight: 700;
            color: #fff;
            margin: 0 auto 1rem;
            box-shadow: 0 0 24px rgba(26, 107, 255, 0.25);
        }
        .timeline-step h4 {
            font-size: 1.05rem;
            font-weight: 600;
            margin-bottom: 0.4rem;
        }
        .timeline-step p {
            font-size: 0.88rem;
            color: var(--text-secondary);
        }
        .timeline-step:not(:last-child)::after {
            content: '→';
            position: absolute;
            right: -1rem;
            top: 2.2rem;
            font-size: 1.4rem;
            color: var(--text-secondary);
            opacity: 0.3;
        }

        /* ===== FAQ ===== */
        .faq-section {
            background: #0b1a2e;
        }
        .faq-list {
            max-width: 800px;
            margin: 0 auto;
            display: flex;
            flex-direction: column;
            gap: 0.8rem;
        }
        .faq-item {
            background: var(--card-bg);
            backdrop-filter: blur(12px);
            -webkit-backdrop-filter: blur(12px);
            border: 1px solid var(--card-border);
            border-radius: var(--radius-md);
            padding: 0;
            overflow: hidden;
            transition: var(--transition);
        }
        .faq-item:hover {
            border-color: var(--card-border-hover);
        }
        .faq-question {
            display: flex;
            align-items: center;
            justify-content: space-between;
            padding: 1.2rem 1.5rem;
            cursor: pointer;
            font-size: 1.05rem;
            font-weight: 500;
            color: var(--text-primary);
            background: transparent;
            border: none;
            width: 100%;
            text-align: left;
            font-family: inherit;
            transition: var(--transition);
        }
        .faq-question i {
            font-size: 0.9rem;
            color: var(--text-secondary);
            transition: transform 0.3s ease;
        }
        .faq-item.open .faq-question i {
            transform: rotate(180deg);
        }
        .faq-answer {
            max-height: 0;
            overflow: hidden;
            transition: max-height 0.4s ease, padding 0.3s ease;
            padding: 0 1.5rem;
            color: var(--text-secondary);
            font-size: 0.95rem;
            line-height: 1.7;
        }
        .faq-item.open .faq-answer {
            max-height: 300px;
            padding: 0 1.5rem 1.2rem;
        }

        /* ===== CTA ===== */
        .cta-section {
            background: linear-gradient(135deg, #0b1a2e 0%, #060e1a 100%);
            padding: 5rem 0;
            text-align: center;
            position: relative;
            overflow: hidden;
        }
        .cta-section::before {
            content: '';
            position: absolute;
            top: -30%;
            left: -10%;
            width: 600px;
            height: 600px;
            background: radial-gradient(circle, rgba(26, 107, 255, 0.06) 0%, transparent 70%);
            pointer-events: none;
        }
        .cta-section .container {
            position: relative;
            z-index: 1;
        }
        .cta-section h2 {
            font-size: 2.2rem;
            font-weight: 700;
            margin-bottom: 0.8rem;
            letter-spacing: -0.01em;
        }
        .cta-section p {
            font-size: 1.1rem;
            color: var(--text-secondary);
            max-width: 600px;
            margin: 0 auto 2rem;
        }
        .cta-btn-group {
            display: flex;
            justify-content: center;
            gap: 1rem;
            flex-wrap: wrap;
        }
        .btn-primary {
            background: linear-gradient(135deg, var(--brand), #0f4dcc);
            color: #fff;
            padding: 14px 44px;
            border-radius: var(--radius-sm);
            font-weight: 600;
            font-size: 1.05rem;
            border: none;
            cursor: pointer;
            transition: var(--transition);
            box-shadow: 0 4px 20px rgba(26, 107, 255, 0.3);
            display: inline-flex;
            align-items: center;
            gap: 8px;
        }
        .btn-primary:hover {
            transform: scale(1.02);
            box-shadow: 0 6px 30px rgba(26, 107, 255, 0.5);
            color: #fff;
        }
        .btn-secondary {
            background: transparent;
            color: var(--text-primary);
            padding: 14px 44px;
            border-radius: var(--radius-sm);
            font-weight: 500;
            font-size: 1.05rem;
            border: 1.5px solid rgba(255, 255, 255, 0.15);
            cursor: pointer;
            transition: var(--transition);
            display: inline-flex;
            align-items: center;
            gap: 8px;
        }
        .btn-secondary:hover {
            border-color: var(--brand);
            color: var(--brand);
            background: rgba(26, 107, 255, 0.06);
        }

        /* ===== Footer ===== */
        .site-footer {
            background: #060e1a;
            border-top: 2px solid transparent;
            border-image: linear-gradient(90deg, #0b1a2e, #1a6bff) 1;
            padding: 4rem 0 2rem;
        }
        .footer-grid {
            display: grid;
            grid-template-columns: 2fr 1fr 1fr 1.2fr;
            gap: 2.5rem;
            margin-bottom: 2.5rem;
        }
        .footer-brand .nav-logo {
            margin-bottom: 1rem;
        }
        .footer-brand p {
            font-size: 0.9rem;
            color: var(--text-secondary);
            line-height: 1.7;
            max-width: 320px;
        }
        .footer-col h4 {
            font-size: 1rem;
            font-weight: 600;
            color: var(--text-primary);
            margin-bottom: 1.2rem;
        }
        .footer-col a {
            display: block;
            font-size: 0.9rem;
            color: var(--text-secondary);
            padding: 0.35rem 0;
            transition: var(--transition);
        }
        .footer-col a:hover {
            color: var(--brand);
        }
        .social-links {
            display: flex;
            gap: 0.8rem;
            margin-top: 0.8rem;
        }
        .social-links a {
            width: 36px;
            height: 36px;
            border-radius: 50%;
            background: rgba(255, 255, 255, 0.05);
            display: flex;
            align-items: center;
            justify-content: center;
            color: var(--text-secondary);
            font-size: 1rem;
            transition: var(--transition);
            padding: 0;
        }
        .social-links a:hover {
            background: rgba(26, 107, 255, 0.15);
            color: var(--brand);
        }
        .footer-bottom {
            border-top: 1px solid rgba(255, 255, 255, 0.05);
            padding-top: 1.5rem;
            text-align: center;
            font-size: 0.85rem;
            color: var(--text-secondary);
        }
        .footer-bottom a {
            color: var(--text-secondary);
        }
        .footer-bottom a:hover {
            color: var(--brand);
        }

        /* ===== Responsive ===== */
        @media (max-width: 1024px) {
            .nav-center {
                gap: 1.2rem;
            }
            .search-box input {
                width: 90px;
            }
            .search-box input:focus {
                width: 120px;
            }
            .category-hero h1 {
                font-size: 2.5rem;
            }
            .value-grid {
                grid-template-columns: repeat(2, 1fr);
            }
            .preview-grid {
                grid-template-columns: repeat(2, 1fr);
            }
            .timeline-grid {
                grid-template-columns: repeat(2, 1fr);
            }
            .timeline-step:nth-child(2)::after {
                display: none;
            }
            .footer-grid {
                grid-template-columns: 1fr 1fr;
            }
            .feature-grid {
                grid-template-columns: 1fr;
                gap: 1.5rem;
            }
            .feature-image {
                order: -1;
            }
        }

        @media (max-width: 768px) {
            :root {
                --container-padding: 16px;
            }
            .site-header {
                height: 64px;
            }
            .nav-center {
                display: none;
            }
            .nav-right .search-box,
            .nav-right .btn-login,
            .nav-right .btn-cta-nav {
                display: none;
            }
            .hamburger {
                display: flex;
            }
            .category-hero {
                padding: 110px 0 60px;
                min-height: 300px;
            }
            .category-hero h1 {
                font-size: 2rem;
            }
            .category-hero .hero-desc {
                font-size: 1rem;
            }
            section {
                padding: 3rem 0;
            }
            .section-title {
                font-size: 1.7rem;
            }
            .value-grid {
                grid-template-columns: 1fr;
            }
            .preview-grid {
                grid-template-columns: 1fr;
            }
            .timeline-grid {
                grid-template-columns: 1fr;
                gap: 1rem;
            }
            .timeline-step::after {
                display: none !important;
            }
            .footer-grid {
                grid-template-columns: 1fr;
                gap: 2rem;
            }
            .footer-brand p {
                max-width: 100%;
            }
            .cta-section h2 {
                font-size: 1.6rem;
            }
            .btn-primary,
            .btn-secondary {
                width: 100%;
                justify-content: center;
            }
            .faq-question {
                font-size: 0.95rem;
                padding: 1rem 1.2rem;
            }
            .faq-answer {
                font-size: 0.9rem;
            }
        }

        @media (max-width: 520px) {
            .category-hero h1 {
                font-size: 1.6rem;
            }
            .section-title {
                font-size: 1.4rem;
            }
            .preview-card .card-img {
                height: 140px;
            }
            .value-card {
                padding: 1.5rem 1rem;
            }
        }

        /* ===== Back to top ===== */
        .back-top {
            position: fixed;
            bottom: 30px;
            right: 30px;
            width: 44px;
            height: 44px;
            border-radius: 50%;
            background: rgba(26, 107, 255, 0.2);
            backdrop-filter: blur(12px);
            border: 1px solid rgba(255, 255, 255, 0.1);
            display: flex;
            align-items: center;
            justify-content: center;
            color: var(--text-primary);
            font-size: 1.2rem;
            cursor: pointer;
            transition: var(--transition);
            z-index: 99;
            opacity: 0;
            visibility: hidden;
        }
        .back-top.visible {
            opacity: 1;
            visibility: visible;
        }
        .back-top:hover {
            background: rgba(26, 107, 255, 0.35);
            transform: translateY(-2px);
        }