/* roulang page: index */
:root {
            --neon-cyan: #00f0ff;
            --neon-cyan-dim: #00b8cc;
            --neon-pink: #ff00e5;
            --neon-pink-dim: #cc00b8;
            --neon-purple: #7b2fff;
            --neon-purple-dim: #5e1fd9;
            --dark-bg: #0a0a0f;
            --dark-panel: #12121a;
            --dark-card: #16161f;
            --dark-border: #1e1e2d;
            --text-primary: #f0f0f5;
            --text-secondary: #c0c0d0;
            --text-weak: #8888aa;
            --radius-sm: 8px;
            --radius-md: 14px;
            --radius-lg: 20px;
            --radius-xl: 28px;
            --shadow-glow-cyan: 0 0 18px rgba(0, 240, 255, 0.35), 0 0 40px rgba(0, 240, 255, 0.12);
            --shadow-glow-pink: 0 0 18px rgba(255, 0, 229, 0.35), 0 0 40px rgba(255, 0, 229, 0.12);
            --shadow-glow-purple: 0 0 18px rgba(123, 47, 255, 0.35), 0 0 40px rgba(123, 47, 255, 0.12);
            --shadow-card: 0 4px 24px rgba(0, 0, 0, 0.4), 0 1px 4px rgba(0, 0, 0, 0.3);
            --shadow-card-hover: 0 12px 40px rgba(0, 0, 0, 0.55), 0 0 30px rgba(0, 240, 255, 0.08);
            --transition-fast: 0.2s cubic-bezier(0.4, 0, 0.2, 1);
            --transition-smooth: 0.35s cubic-bezier(0.4, 0, 0.2, 1);
            --transition-bounce: 0.4s cubic-bezier(0.34, 1.56, 0.64, 1);
        }

        *,
        *::before,
        *::after {
            box-sizing: border-box;
        }

        html {
            scroll-behavior: smooth;
            scroll-padding-top: 80px;
        }

        body {
            margin: 0;
            padding: 0;
            font-family: "PingFang SC", "Microsoft YaHei", "Helvetica Neue", Arial, sans-serif;
            line-height: 1.7;
            background-color: var(--dark-bg);
            color: var(--text-primary);
            -webkit-font-smoothing: antialiased;
            -moz-osx-font-smoothing: grayscale;
            overflow-x: hidden;
            min-height: 100vh;
        }

        a {
            text-decoration: none;
            color: inherit;
            transition: color var(--transition-fast);
        }
        img {
            max-width: 100%;
            height: auto;
            display: block;
        }
        button {
            cursor: pointer;
            font-family: inherit;
            border: none;
            outline: none;
        }
        button:focus-visible,
        a:focus-visible {
            outline: 3px solid var(--neon-cyan);
            outline-offset: 3px;
            border-radius: 4px;
        }
        input {
            font-family: inherit;
            outline: none;
        }

        /* ============ 容器 ============ */
        .container-custom {
            max-width: 1240px;
            margin: 0 auto;
            padding-left: 24px;
            padding-right: 24px;
        }
        @media (max-width: 768px) {
            .container-custom {
                padding-left: 16px;
                padding-right: 16px;
            }
        }

        /* ============ 导航栏 ============ */
        .site-header {
            position: fixed;
            top: 0;
            left: 0;
            right: 0;
            z-index: 1000;
            background: rgba(10, 10, 15, 0.88);
            backdrop-filter: blur(18px);
            -webkit-backdrop-filter: blur(18px);
            border-bottom: 1px solid rgba(255, 255, 255, 0.06);
            transition: all var(--transition-smooth);
            height: 68px;
        }
        .site-header.scrolled {
            background: rgba(10, 10, 15, 0.95);
            border-bottom: 1px solid rgba(0, 240, 255, 0.15);
            box-shadow: 0 2px 30px rgba(0, 0, 0, 0.5);
            height: 62px;
        }
        .header-inner {
            display: flex;
            align-items: center;
            justify-content: space-between;
            height: 100%;
            max-width: 1240px;
            margin: 0 auto;
            padding: 0 24px;
        }
        .logo-link {
            display: flex;
            align-items: center;
            gap: 10px;
            font-size: 1.5rem;
            font-weight: 800;
            letter-spacing: 0.03em;
            color: #fff;
            position: relative;
            transition: all var(--transition-fast);
            white-space: nowrap;
        }
        .logo-link .logo-icon {
            width: 38px;
            height: 38px;
            border-radius: var(--radius-sm);
            background: linear-gradient(135deg, var(--neon-cyan), var(--neon-purple));
            display: flex;
            align-items: center;
            justify-content: center;
            font-size: 1.1rem;
            color: #fff;
            box-shadow: var(--shadow-glow-cyan);
            flex-shrink: 0;
        }
        .logo-link .logo-text {
            background: linear-gradient(135deg, #fff, #d0f0ff);
            -webkit-background-clip: text;
            background-clip: text;
            -webkit-text-fill-color: transparent;
            text-shadow: none;
        }
        .logo-link:hover .logo-icon {
            box-shadow: var(--shadow-glow-pink);
            transform: scale(1.05);
        }
        .nav-list {
            display: flex;
            align-items: center;
            gap: 6px;
            list-style: none;
            margin: 0;
            padding: 0;
        }
        .nav-list li a {
            display: inline-block;
            padding: 9px 16px;
            border-radius: 20px;
            font-size: 0.93rem;
            font-weight: 500;
            color: var(--text-secondary);
            transition: all var(--transition-fast);
            position: relative;
            white-space: nowrap;
        }
        .nav-list li a:hover {
            color: #fff;
            background: rgba(255, 255, 255, 0.05);
        }
        .nav-list li a.nav-active {
            color: var(--neon-cyan);
            background: rgba(0, 240, 255, 0.08);
            font-weight: 600;
        }
        .nav-cta-btn {
            display: inline-block;
            padding: 10px 22px;
            border-radius: 22px;
            font-size: 0.9rem;
            font-weight: 600;
            background: linear-gradient(135deg, var(--neon-cyan), var(--neon-purple));
            color: #fff !important;
            box-shadow: var(--shadow-glow-cyan);
            transition: all var(--transition-bounce);
            white-space: nowrap;
        }
        .nav-cta-btn:hover {
            box-shadow: var(--shadow-glow-pink);
            transform: translateY(-2px);
            background: linear-gradient(135deg, var(--neon-pink), var(--neon-purple));
        }
        /* 移动端菜单按钮 */
        .mobile-toggle {
            display: none;
            background: transparent;
            border: none;
            color: #fff;
            font-size: 1.6rem;
            padding: 8px;
            cursor: pointer;
            transition: color var(--transition-fast);
            z-index: 1001;
        }
        .mobile-toggle:hover {
            color: var(--neon-cyan);
        }
        @media (max-width: 920px) {
            .mobile-toggle {
                display: block;
            }
            .nav-list {
                position: fixed;
                top: 0;
                right: -100%;
                width: 280px;
                height: 100vh;
                background: rgba(16, 16, 26, 0.98);
                backdrop-filter: blur(20px);
                -webkit-backdrop-filter: blur(20px);
                flex-direction: column;
                padding: 90px 28px 40px;
                gap: 8px;
                transition: right var(--transition-smooth);
                border-left: 1px solid rgba(255, 255, 255, 0.06);
                box-shadow: -8px 0 40px rgba(0, 0, 0, 0.6);
                z-index: 1000;
            }
            .nav-list.open {
                right: 0;
            }
            .nav-list li {
                width: 100%;
            }
            .nav-list li a {
                display: block;
                padding: 13px 18px;
                border-radius: var(--radius-sm);
                font-size: 1rem;
                width: 100%;
            }
            .nav-cta-btn {
                text-align: center;
                margin-top: 8px;
                width: 100%;
                display: block;
            }
            .mobile-overlay {
                display: none;
                position: fixed;
                inset: 0;
                background: rgba(0, 0, 0, 0.5);
                z-index: 999;
                cursor: pointer;
            }
            .mobile-overlay.show {
                display: block;
            }
        }

        /* ============ 首屏 Hero ============ */
        .hero-section {
            position: relative;
            min-height: 100vh;
            display: flex;
            align-items: center;
            justify-content: center;
            text-align: center;
            padding: 120px 24px 80px;
            overflow: hidden;
            background-color: #06060d;
        }
        .hero-bg {
            position: absolute;
            inset: 0;
            background-image: url('/assets/images/backpic/back-1.webp');
            background-size: cover;
            background-position: center;
            background-repeat: no-repeat;
            z-index: 0;
            opacity: 0.55;
        }
        .hero-overlay {
            position: absolute;
            inset: 0;
            background: linear-gradient(180deg, rgba(6, 6, 13, 0.75) 0%, rgba(10, 10, 20, 0.85) 40%, rgba(10, 10, 15, 0.95) 100%);
            z-index: 1;
        }
        .hero-grid-lines {
            position: absolute;
            inset: 0;
            z-index: 1;
            background-image:
                linear-gradient(rgba(0, 240, 255, 0.04) 1px, transparent 1px),
                linear-gradient(90deg, rgba(0, 240, 255, 0.04) 1px, transparent 1px);
            background-size: 60px 60px;
            mask-image: radial-gradient(ellipse at center, black 30%, transparent 70%);
            -webkit-mask-image: radial-gradient(ellipse at center, black 30%, transparent 70%);
        }
        .hero-content {
            position: relative;
            z-index: 2;
            max-width: 800px;
            margin: 0 auto;
        }
        .hero-badge {
            display: inline-block;
            padding: 7px 18px;
            border-radius: 20px;
            font-size: 0.85rem;
            font-weight: 600;
            letter-spacing: 0.06em;
            background: rgba(0, 240, 255, 0.1);
            border: 1px solid rgba(0, 240, 255, 0.3);
            color: var(--neon-cyan);
            margin-bottom: 24px;
            animation: pulse-badge 3s ease-in-out infinite;
        }
        @keyframes pulse-badge {
            0%,
            100% {
                box-shadow: 0 0 8px rgba(0, 240, 255, 0.2);
            }
            50% {
                box-shadow: 0 0 22px rgba(0, 240, 255, 0.45);
            }
        }
        .hero-title {
            font-size: 3.6rem;
            font-weight: 900;
            letter-spacing: 0.02em;
            line-height: 1.2;
            margin: 0 0 20px;
            color: #fff;
            text-shadow: 0 0 60px rgba(0, 240, 255, 0.25), 0 0 120px rgba(123, 47, 255, 0.2);
        }
        .hero-title .highlight {
            background: linear-gradient(135deg, var(--neon-cyan), var(--neon-pink));
            -webkit-background-clip: text;
            background-clip: text;
            -webkit-text-fill-color: transparent;
            text-shadow: none;
        }
        .hero-subtitle {
            font-size: 1.2rem;
            color: var(--text-secondary);
            margin: 0 0 36px;
            line-height: 1.6;
            max-width: 600px;
            margin-left: auto;
            margin-right: auto;
        }
        .hero-btn-group {
            display: flex;
            gap: 16px;
            flex-wrap: wrap;
            justify-content: center;
        }
        .btn-primary {
            display: inline-flex;
            align-items: center;
            gap: 8px;
            padding: 14px 32px;
            border-radius: 28px;
            font-size: 1rem;
            font-weight: 700;
            background: linear-gradient(135deg, var(--neon-cyan), var(--neon-purple));
            color: #fff;
            box-shadow: var(--shadow-glow-cyan);
            transition: all var(--transition-bounce);
            letter-spacing: 0.03em;
        }
        .btn-primary:hover {
            box-shadow: var(--shadow-glow-pink);
            transform: translateY(-3px);
            background: linear-gradient(135deg, var(--neon-pink), var(--neon-purple));
        }
        .btn-outline {
            display: inline-flex;
            align-items: center;
            gap: 8px;
            padding: 14px 32px;
            border-radius: 28px;
            font-size: 1rem;
            font-weight: 600;
            background: transparent;
            color: #fff;
            border: 2px solid rgba(255, 255, 255, 0.25);
            transition: all var(--transition-bounce);
            letter-spacing: 0.03em;
        }
        .btn-outline:hover {
            border-color: var(--neon-cyan);
            box-shadow: var(--shadow-glow-cyan);
            transform: translateY(-3px);
            background: rgba(0, 240, 255, 0.05);
        }
        @media (max-width: 768px) {
            .hero-title {
                font-size: 2.2rem;
            }
            .hero-subtitle {
                font-size: 1rem;
            }
            .hero-btn-group {
                flex-direction: column;
                align-items: center;
            }
            .btn-primary,
            .btn-outline {
                width: 100%;
                max-width: 320px;
                justify-content: center;
                padding: 13px 24px;
                font-size: 0.95rem;
            }
        }
        @media (max-width: 520px) {
            .hero-title {
                font-size: 1.7rem;
            }
            .hero-subtitle {
                font-size: 0.9rem;
            }
            .hero-badge {
                font-size: 0.75rem;
                padding: 5px 14px;
            }
        }

        /* ============ 板块通用 ============ */
        .section-block {
            padding: 80px 0;
            position: relative;
        }
        .section-block.section-alt {
            background-color: var(--dark-panel);
        }
        .section-label {
            display: inline-block;
            font-size: 0.82rem;
            font-weight: 700;
            letter-spacing: 0.08em;
            text-transform: uppercase;
            color: var(--neon-cyan);
            margin-bottom: 10px;
        }
        .section-title {
            font-size: 2.2rem;
            font-weight: 800;
            color: #fff;
            margin: 0 0 14px;
            letter-spacing: 0.02em;
        }
        .section-desc {
            font-size: 1.05rem;
            color: var(--text-weak);
            max-width: 640px;
            margin: 0 auto 40px;
            line-height: 1.7;
        }
        .text-center {
            text-align: center;
        }
        @media (max-width: 768px) {
            .section-block {
                padding: 52px 0;
            }
            .section-title {
                font-size: 1.6rem;
            }
            .section-desc {
                font-size: 0.95rem;
                margin-bottom: 28px;
            }
        }

        /* ============ 核心优势卡片 ============ */
        .features-grid {
            display: grid;
            grid-template-columns: repeat(4, 1fr);
            gap: 20px;
        }
        .feature-card {
            background: var(--dark-card);
            border: 1px solid var(--dark-border);
            border-radius: var(--radius-lg);
            padding: 32px 24px;
            text-align: center;
            transition: all var(--transition-smooth);
            position: relative;
            overflow: hidden;
            box-shadow: var(--shadow-card);
        }
        .feature-card::before {
            content: '';
            position: absolute;
            top: 0;
            left: 50%;
            transform: translateX(-50%);
            width: 60px;
            height: 3px;
            border-radius: 0 0 3px 3px;
            background: linear-gradient(90deg, var(--neon-cyan), var(--neon-purple));
            opacity: 0;
            transition: opacity var(--transition-smooth);
        }
        .feature-card:hover {
            border-color: rgba(0, 240, 255, 0.35);
            box-shadow: var(--shadow-card-hover);
            transform: translateY(-6px);
        }
        .feature-card:hover::before {
            opacity: 1;
        }
        .feature-icon {
            width: 56px;
            height: 56px;
            border-radius: var(--radius-md);
            display: flex;
            align-items: center;
            justify-content: center;
            margin: 0 auto 18px;
            font-size: 1.5rem;
            background: rgba(0, 240, 255, 0.08);
            color: var(--neon-cyan);
            transition: all var(--transition-smooth);
        }
        .feature-card:hover .feature-icon {
            background: rgba(255, 0, 229, 0.12);
            color: var(--neon-pink);
            box-shadow: var(--shadow-glow-pink);
        }
        .feature-card h3 {
            font-size: 1.1rem;
            font-weight: 700;
            color: #fff;
            margin: 0 0 8px;
        }
        .feature-card p {
            font-size: 0.9rem;
            color: var(--text-weak);
            margin: 0;
            line-height: 1.5;
        }
        @media (max-width: 1024px) {
            .features-grid {
                grid-template-columns: repeat(2, 1fr);
                gap: 16px;
            }
        }
        @media (max-width: 520px) {
            .features-grid {
                grid-template-columns: 1fr;
                gap: 14px;
            }
            .feature-card {
                padding: 24px 18px;
            }
        }

        /* ============ 服务卡片 ============ */
        .services-grid {
            display: grid;
            grid-template-columns: repeat(3, 1fr);
            gap: 24px;
        }
        .service-card {
            background: var(--dark-card);
            border: 1px solid var(--dark-border);
            border-radius: var(--radius-lg);
            overflow: hidden;
            transition: all var(--transition-smooth);
            box-shadow: var(--shadow-card);
            display: flex;
            flex-direction: column;
        }
        .service-card:hover {
            border-color: rgba(0, 240, 255, 0.3);
            box-shadow: var(--shadow-card-hover);
            transform: translateY(-5px);
        }
        .service-card-img {
            width: 100%;
            height: 200px;
            object-fit: cover;
            display: block;
        }
        .service-card-body {
            padding: 22px 20px;
            flex: 1;
            display: flex;
            flex-direction: column;
        }
        .service-card-body h3 {
            font-size: 1.08rem;
            font-weight: 700;
            color: #fff;
            margin: 0 0 8px;
        }
        .service-card-body p {
            font-size: 0.9rem;
            color: var(--text-weak);
            margin: 0 0 16px;
            line-height: 1.5;
            flex: 1;
        }
        .service-tag {
            display: inline-block;
            padding: 5px 12px;
            border-radius: 14px;
            font-size: 0.78rem;
            font-weight: 600;
            background: rgba(0, 240, 255, 0.08);
            color: var(--neon-cyan);
            align-self: flex-start;
            transition: all var(--transition-fast);
        }
        .service-card:hover .service-tag {
            background: rgba(255, 0, 229, 0.1);
            color: var(--neon-pink);
        }
        @media (max-width: 1024px) {
            .services-grid {
                grid-template-columns: repeat(2, 1fr);
                gap: 18px;
            }
        }
        @media (max-width: 600px) {
            .services-grid {
                grid-template-columns: 1fr;
                gap: 16px;
            }
            .service-card-img {
                height: 180px;
            }
        }

        /* ============ 数据统计 ============ */
        .stats-section {
            position: relative;
            background-color: #0d0d17;
            overflow: hidden;
        }
        .stats-bg {
            position: absolute;
            inset: 0;
            background-image: url('/assets/images/backpic/back-2.webp');
            background-size: cover;
            background-position: center;
            background-repeat: no-repeat;
            opacity: 0.18;
            z-index: 0;
        }
        .stats-overlay {
            position: absolute;
            inset: 0;
            background: rgba(10, 10, 20, 0.85);
            z-index: 1;
        }
        .stats-content {
            position: relative;
            z-index: 2;
        }
        .stats-grid {
            display: grid;
            grid-template-columns: repeat(4, 1fr);
            gap: 24px;
            text-align: center;
        }
        .stat-item {
            padding: 28px 16px;
            border-radius: var(--radius-lg);
            background: rgba(22, 22, 31, 0.7);
            border: 1px solid rgba(255, 255, 255, 0.06);
            transition: all var(--transition-smooth);
        }
        .stat-item:hover {
            border-color: rgba(0, 240, 255, 0.25);
            box-shadow: var(--shadow-glow-cyan);
            transform: translateY(-4px);
        }
        .stat-number {
            font-size: 3rem;
            font-weight: 900;
            letter-spacing: 0.02em;
            background: linear-gradient(135deg, var(--neon-cyan), var(--neon-pink));
            -webkit-background-clip: text;
            background-clip: text;
            -webkit-text-fill-color: transparent;
            line-height: 1.1;
        }
        .stat-label {
            font-size: 0.9rem;
            color: var(--text-weak);
            margin-top: 6px;
            font-weight: 500;
        }
        @media (max-width: 768px) {
            .stats-grid {
                grid-template-columns: repeat(2, 1fr);
                gap: 16px;
            }
            .stat-number {
                font-size: 2.2rem;
            }
        }
        @media (max-width: 520px) {
            .stats-grid {
                grid-template-columns: 1fr 1fr;
                gap: 12px;
            }
            .stat-number {
                font-size: 1.8rem;
            }
            .stat-item {
                padding: 20px 10px;
            }
        }

        /* ============ 流程 Bracket ============ */
        .bracket-container {
            display: flex;
            align-items: stretch;
            justify-content: center;
            gap: 0;
            flex-wrap: nowrap;
            overflow-x: auto;
            padding: 20px 0;
            -webkit-overflow-scrolling: touch;
        }
        .bracket-round {
            display: flex;
            flex-direction: column;
            justify-content: space-around;
            gap: 30px;
            min-width: 140px;
            position: relative;
        }
        .bracket-round-label {
            text-align: center;
            font-size: 0.8rem;
            font-weight: 700;
            letter-spacing: 0.06em;
            color: var(--neon-cyan);
            margin-bottom: 6px;
            text-transform: uppercase;
        }
        .bracket-slot {
            background: var(--dark-card);
            border: 1px solid var(--dark-border);
            border-radius: var(--radius-md);
            padding: 14px 16px;
            text-align: center;
            font-weight: 600;
            font-size: 0.9rem;
            color: #fff;
            transition: all var(--transition-fast);
            min-width: 120px;
            position: relative;
        }
        .bracket-slot.winner {
            border-color: var(--neon-cyan);
            box-shadow: var(--shadow-glow-cyan);
            background: rgba(0, 240, 255, 0.06);
        }
        .bracket-connector {
            display: flex;
            align-items: center;
            justify-content: center;
            min-width: 50px;
            color: var(--neon-purple);
            font-size: 1.2rem;
            font-weight: 700;
            flex-shrink: 0;
        }
        @media (max-width: 768px) {
            .bracket-container {
                justify-content: flex-start;
                gap: 0;
            }
            .bracket-round {
                min-width: 110px;
                gap: 20px;
            }
            .bracket-slot {
                padding: 10px 12px;
                font-size: 0.8rem;
                min-width: 90px;
            }
            .bracket-connector {
                min-width: 30px;
                font-size: 1rem;
            }
        }

        /* ============ FAQ ============ */
        .faq-list {
            max-width: 780px;
            margin: 0 auto;
            display: flex;
            flex-direction: column;
            gap: 12px;
        }
        .faq-item {
            background: var(--dark-card);
            border: 1px solid var(--dark-border);
            border-radius: var(--radius-md);
            overflow: hidden;
            transition: all var(--transition-fast);
        }
        .faq-item:hover {
            border-color: rgba(0, 240, 255, 0.2);
        }
        .faq-item summary {
            padding: 18px 22px;
            font-weight: 700;
            font-size: 1rem;
            color: #fff;
            cursor: pointer;
            list-style: none;
            display: flex;
            align-items: center;
            justify-content: space-between;
            gap: 12px;
            user-select: none;
            transition: color var(--transition-fast);
        }
        .faq-item summary::-webkit-details-marker {
            display: none;
        }
        .faq-item summary::after {
            content: '\f107';
            font-family: 'Font Awesome 6 Free';
            font-weight: 900;
            font-size: 1rem;
            color: var(--text-weak);
            transition: transform var(--transition-fast);
            flex-shrink: 0;
        }
        .faq-item[open] summary::after {
            transform: rotate(180deg);
            color: var(--neon-cyan);
        }
        .faq-item[open] summary {
            color: var(--neon-cyan);
        }
        .faq-item[open] {
            border-color: rgba(0, 240, 255, 0.3);
            box-shadow: 0 0 20px rgba(0, 240, 255, 0.06);
        }
        .faq-answer {
            padding: 0 22px 20px;
            font-size: 0.93rem;
            color: var(--text-weak);
            line-height: 1.6;
        }
        @media (max-width: 520px) {
            .faq-item summary {
                padding: 15px 16px;
                font-size: 0.9rem;
            }
            .faq-answer {
                padding: 0 16px 16px;
                font-size: 0.85rem;
            }
        }

        /* ============ CTA 板块 ============ */
        .cta-section {
            position: relative;
            background: linear-gradient(135deg, #0f0f1f 0%, #14142a 100%);
            overflow: hidden;
            text-align: center;
            padding: 70px 0;
        }
        .cta-glow {
            position: absolute;
            width: 400px;
            height: 400px;
            border-radius: 50%;
            filter: blur(120px);
            opacity: 0.3;
            z-index: 0;
            pointer-events: none;
        }
        .cta-glow.glow-cyan {
            background: var(--neon-cyan);
            top: -150px;
            left: -100px;
        }
        .cta-glow.glow-pink {
            background: var(--neon-pink);
            bottom: -150px;
            right: -100px;
        }
        .cta-content {
            position: relative;
            z-index: 2;
        }
        .cta-content h2 {
            font-size: 2rem;
            font-weight: 800;
            color: #fff;
            margin: 0 0 12px;
        }
        .cta-content p {
            font-size: 1.05rem;
            color: var(--text-weak);
            margin: 0 auto 28px;
            max-width: 500px;
        }
        @media (max-width: 520px) {
            .cta-content h2 {
                font-size: 1.4rem;
            }
            .cta-content p {
                font-size: 0.9rem;
            }
        }

        /* ============ 页脚 ============ */
        .site-footer {
            background: #08080f;
            border-top: 1px solid rgba(255, 255, 255, 0.05);
            padding: 48px 0 28px;
            text-align: center;
        }
        .footer-logo {
            font-size: 1.3rem;
            font-weight: 800;
            color: #fff;
            margin-bottom: 8px;
            letter-spacing: 0.03em;
        }
        .footer-desc {
            font-size: 0.88rem;
            color: var(--text-weak);
            margin: 0 auto 20px;
            max-width: 500px;
            line-height: 1.5;
        }
        .footer-links {
            display: flex;
            gap: 20px;
            flex-wrap: wrap;
            justify-content: center;
            margin-bottom: 20px;
        }
        .footer-links a {
            font-size: 0.88rem;
            color: var(--text-weak);
            transition: color var(--transition-fast);
        }
        .footer-links a:hover {
            color: var(--neon-cyan);
        }
        .footer-bottom {
            font-size: 0.8rem;
            color: rgba(255, 255, 255, 0.3);
            padding-top: 16px;
            border-top: 1px solid rgba(255, 255, 255, 0.04);
        }
        @media (max-width: 520px) {
            .site-footer {
                padding: 32px 0 20px;
            }
            .footer-links {
                gap: 12px;
            }
        }

        /* ============ 回到顶部按钮 ============ */
        .back-to-top {
            position: fixed;
            bottom: 28px;
            right: 28px;
            z-index: 900;
            width: 44px;
            height: 44px;
            border-radius: 50%;
            background: var(--dark-card);
            border: 1px solid var(--dark-border);
            color: #fff;
            font-size: 1.1rem;
            cursor: pointer;
            display: flex;
            align-items: center;
            justify-content: center;
            transition: all var(--transition-bounce);
            opacity: 0;
            pointer-events: none;
            box-shadow: var(--shadow-card);
        }
        .back-to-top.visible {
            opacity: 1;
            pointer-events: auto;
        }
        .back-to-top:hover {
            border-color: var(--neon-cyan);
            box-shadow: var(--shadow-glow-cyan);
            transform: translateY(-3px);
            background: rgba(0, 240, 255, 0.08);
        }
        @media (max-width: 520px) {
            .back-to-top {
                bottom: 16px;
                right: 16px;
                width: 38px;
                height: 38px;
                font-size: 0.9rem;
            }
        }