/* roulang page: index */
:root {
            --brand-50: #eff6ff;
            --brand-100: #dbeafe;
            --brand-200: #bfdbfe;
            --brand-300: #93c5fd;
            --brand-400: #60a5fa;
            --brand-500: #3b82f6;
            --brand-600: #2563eb;
            --brand-700: #1d4ed8;
            --brand-800: #1e40af;
            --brand-900: #1e3a8a;
            --ink-50: #f8fafc;
            --ink-100: #f1f5f9;
            --ink-200: #e2e8f0;
            --ink-300: #cbd5e1;
            --ink-400: #94a3b8;
            --ink-500: #64748b;
            --ink-600: #475569;
            --ink-700: #334155;
            --ink-800: #1e293b;
            --ink-900: #0f172a;
            --ink-950: #020617;
            --radius-sm: 0.375rem;
            --radius-md: 0.625rem;
            --radius-lg: 0.875rem;
            --radius-xl: 1.25rem;
            --radius-2xl: 1.5rem;
            --radius-3xl: 2rem;
            --shadow-card: 0 1px 3px rgba(15, 23, 42, 0.06), 0 8px 24px rgba(15, 23, 42, 0.08);
            --shadow-card-hover: 0 2px 6px rgba(15, 23, 42, 0.08), 0 16px 40px rgba(15, 23, 42, 0.14);
            --transition-fast: 150ms cubic-bezier(0.4, 0, 0.2, 1);
            --transition-base: 250ms cubic-bezier(0.4, 0, 0.2, 1);
            --transition-slow: 400ms cubic-bezier(0.4, 0, 0.2, 1);
            --sidebar-width: 240px;
        }

        *,
        *::before,
        *::after {
            box-sizing: border-box;
            margin: 0;
            padding: 0;
        }

        html {
            scroll-behavior: smooth;
            -webkit-text-size-adjust: 100%;
        }

        body {
            font-family: 'Inter', 'PingFang SC', 'Hiragino Sans GB', 'Microsoft YaHei', 'Noto Sans SC', -apple-system, BlinkMacSystemFont, 'Segoe UI', sans-serif;
            background-color: var(--ink-50);
            color: var(--ink-800);
            line-height: 1.6;
            -webkit-font-smoothing: antialiased;
            -moz-osx-font-smoothing: grayscale;
            min-height: 100vh;
        }

        a {
            color: inherit;
            text-decoration: none;
            transition: color var(--transition-fast);
        }

        a:focus-visible,
        button:focus-visible,
        input:focus-visible,
        select:focus-visible,
        textarea:focus-visible {
            outline: 2px solid var(--brand-500);
            outline-offset: 2px;
            border-radius: 4px;
        }

        img {
            display: block;
            max-width: 100%;
            height: auto;
        }

        button {
            cursor: pointer;
            border: none;
            background: none;
            font-family: inherit;
        }

        input,
        select,
        textarea {
            font-family: inherit;
            font-size: 1rem;
        }

        ::selection {
            background-color: var(--brand-200);
            color: var(--brand-900);
        }

        /* 左侧导航 - 桌面端 */
        .sidebar-nav {
            position: fixed;
            top: 0;
            left: 0;
            bottom: 0;
            width: var(--sidebar-width);
            background: #ffffff;
            border-right: 1px solid var(--ink-200);
            display: flex;
            flex-direction: column;
            z-index: 50;
            transition: transform var(--transition-slow), box-shadow var(--transition-base);
        }

        .sidebar-nav .logo-area {
            padding: 1.5rem 1.25rem;
            border-bottom: 1px solid var(--ink-100);
        }

        .sidebar-nav .nav-list {
            padding: 1rem 0.75rem;
            flex: 1;
            overflow-y: auto;
        }

        .sidebar-nav .nav-link {
            display: flex;
            align-items: center;
            gap: 0.625rem;
            padding: 0.625rem 0.875rem;
            border-radius: var(--radius-md);
            font-size: 0.9rem;
            font-weight: 500;
            color: var(--ink-600);
            transition: background-color var(--transition-fast), color var(--transition-fast);
            position: relative;
        }

        .sidebar-nav .nav-link:hover {
            background-color: var(--brand-50);
            color: var(--brand-700);
        }

        .sidebar-nav .nav-link.active {
            background-color: var(--brand-50);
            color: var(--brand-700);
            font-weight: 600;
        }

        .sidebar-nav .nav-link.active::before {
            content: '';
            position: absolute;
            left: -0.75rem;
            top: 50%;
            transform: translateY(-50%);
            width: 3px;
            height: 1.5rem;
            background-color: var(--brand-600);
            border-radius: 0 3px 3px 0;
        }

        .sidebar-nav .nav-link i {
            width: 1.125rem;
            text-align: center;
            font-size: 0.95rem;
        }

        .sidebar-nav .sidebar-footer {
            padding: 1rem 1.25rem;
            border-top: 1px solid var(--ink-100);
            font-size: 0.75rem;
            color: var(--ink-400);
        }

        /* 主内容区域 */
        .main-wrapper {
            margin-left: var(--sidebar-width);
            min-height: 100vh;
            transition: margin-left var(--transition-slow);
        }

        /* 移动端顶部栏 */
        .mobile-topbar {
            display: none;
            position: fixed;
            top: 0;
            left: 0;
            right: 0;
            height: 56px;
            background: #ffffff;
            border-bottom: 1px solid var(--ink-200);
            z-index: 40;
            align-items: center;
            padding: 0 1rem;
            gap: 0.75rem;
        }

        .mobile-topbar .hamburger {
            display: flex;
            align-items: center;
            justify-content: center;
            width: 40px;
            height: 40px;
            border-radius: var(--radius-sm);
            background: var(--ink-50);
            color: var(--ink-700);
            font-size: 1.1rem;
            transition: background-color var(--transition-fast);
        }

        .mobile-topbar .hamburger:hover {
            background: var(--brand-50);
            color: var(--brand-700);
        }

        /* 移动端抽屉 */
        .mobile-drawer {
            position: fixed;
            top: 0;
            left: 0;
            bottom: 0;
            width: 280px;
            max-width: 85vw;
            background: #ffffff;
            z-index: 60;
            transform: translateX(-100%);
            transition: transform var(--transition-slow);
            box-shadow: 0 0 40px rgba(15, 23, 42, 0.18);
            display: flex;
            flex-direction: column;
        }

        .mobile-drawer.open {
            transform: translateX(0);
        }

        .mobile-drawer-overlay {
            position: fixed;
            inset: 0;
            background: rgba(15, 23, 42, 0.5);
            z-index: 55;
            opacity: 0;
            pointer-events: none;
            transition: opacity var(--transition-base);
        }

        .mobile-drawer-overlay.show {
            opacity: 1;
            pointer-events: auto;
        }

        .mobile-drawer .drawer-header {
            padding: 1.25rem;
            border-bottom: 1px solid var(--ink-100);
            display: flex;
            align-items: center;
            justify-content: space-between;
        }

        .mobile-drawer .close-btn {
            width: 36px;
            height: 36px;
            border-radius: var(--radius-sm);
            background: var(--ink-50);
            color: var(--ink-600);
            display: flex;
            align-items: center;
            justify-content: center;
            transition: background-color var(--transition-fast);
        }

        .mobile-drawer .close-btn:hover {
            background: var(--brand-50);
            color: var(--brand-700);
        }

        .mobile-drawer .drawer-nav {
            padding: 0.75rem;
            flex: 1;
            overflow-y: auto;
        }

        .mobile-drawer .drawer-nav .nav-link {
            display: flex;
            align-items: center;
            gap: 0.625rem;
            padding: 0.75rem 0.875rem;
            border-radius: var(--radius-md);
            font-size: 0.925rem;
            font-weight: 500;
            color: var(--ink-600);
            transition: background-color var(--transition-fast), color var(--transition-fast);
        }

        .mobile-drawer .drawer-nav .nav-link:hover,
        .mobile-drawer .drawer-nav .nav-link.active {
            background-color: var(--brand-50);
            color: var(--brand-700);
        }

        /* 通用容器和标题 */
        .page-container {
            max-width: var(--max-content, 1120px);
            margin: 0 auto;
            padding-left: 2rem;
            padding-right: 2rem;
        }

        .section-title {
            font-size: 1.75rem;
            font-weight: 700;
            color: var(--ink-900);
            letter-spacing: -0.02em;
            line-height: 1.3;
        }

        .section-subtitle {
            font-size: 1rem;
            color: var(--ink-500);
            line-height: 1.8;
            margin-top: 0.625rem;
            max-width: 720px;
        }

        /* 卡片 */
        .card {
            background: #ffffff;
            border-radius: var(--radius-lg);
            box-shadow: var(--shadow-card);
            border: 1px solid var(--ink-100);
            transition: box-shadow var(--transition-base), transform var(--transition-base), border-color var(--transition-base);
        }

        .card:hover {
            box-shadow: var(--shadow-card-hover);
            border-color: var(--brand-200);
        }

        .card-hover-lift {
            transition: box-shadow var(--transition-base), transform var(--transition-base), border-color var(--transition-base);
        }

        .card-hover-lift:hover {
            box-shadow: var(--shadow-card-hover);
            transform: translateY(-3px);
            border-color: var(--brand-200);
        }

        /* 按钮 */
        .btn {
            display: inline-flex;
            align-items: center;
            justify-content: center;
            gap: 0.5rem;
            padding: 0.625rem 1.25rem;
            border-radius: var(--radius-md);
            font-size: 0.925rem;
            font-weight: 600;
            letter-spacing: 0.01em;
            transition: all var(--transition-fast);
            white-space: nowrap;
            line-height: 1.4;
        }

        .btn-primary {
            background-color: var(--brand-600);
            color: #ffffff;
            box-shadow: 0 1px 2px rgba(37, 99, 235, 0.2);
        }

        .btn-primary:hover {
            background-color: var(--brand-700);
            box-shadow: 0 4px 12px rgba(37, 99, 235, 0.35);
            transform: translateY(-1px);
        }

        .btn-primary:active {
            background-color: var(--brand-800);
            transform: translateY(0);
        }

        .btn-secondary {
            background-color: #ffffff;
            color: var(--brand-700);
            border: 1px solid var(--brand-200);
        }

        .btn-secondary:hover {
            background-color: var(--brand-50);
            border-color: var(--brand-300);
        }

        .btn-ghost {
            background-color: transparent;
            color: var(--ink-600);
            border: 1px solid var(--ink-200);
        }

        .btn-ghost:hover {
            background-color: var(--ink-50);
            border-color: var(--ink-300);
            color: var(--ink-800);
        }

        .btn-lg {
            padding: 0.75rem 1.75rem;
            font-size: 1rem;
            border-radius: var(--radius-lg);
        }

        .btn-sm {
            padding: 0.4rem 0.875rem;
            font-size: 0.825rem;
            border-radius: var(--radius-md);
        }

        /* 标签 */
        .badge {
            display: inline-flex;
            align-items: center;
            gap: 0.25rem;
            padding: 0.25rem 0.625rem;
            border-radius: 9999px;
            font-size: 0.75rem;
            font-weight: 600;
            letter-spacing: 0.02em;
            line-height: 1.4;
        }

        .badge-blue {
            background-color: var(--brand-50);
            color: var(--brand-700);
            border: 1px solid var(--brand-100);
        }

        .badge-green {
            background-color: #f0fdf4;
            color: #16a34a;
            border: 1px solid #bbf7d0;
        }

        .badge-orange {
            background-color: #fff7ed;
            color: #ea580c;
            border: 1px solid #fed7aa;
        }

        /* 数据统计数字 */
        .stat-number {
            font-size: 1.75rem;
            font-weight: 700;
            letter-spacing: -0.02em;
            line-height: 1.2;
        }

        /* FAQ details */
        details.faq-item {
            background: #ffffff;
            border: 1px solid var(--ink-100);
            border-radius: var(--radius-lg);
            transition: border-color var(--transition-fast), box-shadow var(--transition-fast);
        }

        details.faq-item[open] {
            border-color: var(--brand-200);
            box-shadow: var(--shadow-card);
        }

        details.faq-item summary {
            cursor: pointer;
            padding: 1.125rem 1.375rem;
            font-weight: 600;
            font-size: 0.975rem;
            color: var(--ink-800);
            display: flex;
            align-items: center;
            justify-content: space-between;
            gap: 1rem;
            list-style: none;
            user-select: none;
            transition: color var(--transition-fast);
        }

        details.faq-item summary::-webkit-details-marker {
            display: none;
        }

        details.faq-item summary:hover {
            color: var(--brand-700);
        }

        details.faq-item summary .faq-icon {
            font-size: 0.875rem;
            color: var(--ink-400);
            transition: transform var(--transition-base);
            flex-shrink: 0;
        }

        details.faq-item[open] summary .faq-icon {
            transform: rotate(180deg);
            color: var(--brand-600);
        }

        details.faq-item .faq-body {
            padding: 0 1.375rem 1.25rem;
            color: var(--ink-500);
            font-size: 0.925rem;
            line-height: 1.8;
        }

        /* 倒计时 */
        .countdown-unit {
            background: rgba(255, 255, 255, 0.08);
            border: 1px solid rgba(255, 255, 255, 0.15);
            border-radius: var(--radius-md);
            padding: 0.75rem 0.875rem;
            min-width: 68px;
            text-align: center;
            backdrop-filter: blur(12px);
        }

        .countdown-unit .countdown-number {
            font-size: 1.625rem;
            font-weight: 700;
            color: #ffffff;
            line-height: 1.2;
            letter-spacing: -0.02em;
            font-variant-numeric: tabular-nums;
        }

        .countdown-unit .countdown-label {
            font-size: 0.7rem;
            color: rgba(255, 255, 255, 0.6);
            font-weight: 500;
            letter-spacing: 0.04em;
            text-transform: uppercase;
            margin-top: 0.125rem;
        }

        /* Hero 数据榜 */
        .hero-rank-item {
            display: flex;
            align-items: center;
            gap: 0.75rem;
            padding: 0.5rem 0.625rem;
            border-radius: var(--radius-md);
            background: rgba(255, 255, 255, 0.04);
            border: 1px solid rgba(255, 255, 255, 0.06);
            transition: background-color var(--transition-fast);
        }

        .hero-rank-item:hover {
            background: rgba(255, 255, 255, 0.08);
        }

        .rank-number {
            font-size: 0.8rem;
            font-weight: 700;
            color: rgba(255, 255, 255, 0.5);
            width: 1.75rem;
            text-align: center;
            flex-shrink: 0;
        }

        .rank-number.top-1 {
            color: #fbbf24;
        }
        .rank-number.top-2 {
            color: #e5e7eb;
        }
        .rank-number.top-3 {
            color: #d97706;
        }

        /* 表单项 */
        .form-input {
            width: 100%;
            padding: 0.625rem 0.875rem;
            border-radius: var(--radius-md);
            border: 1px solid var(--ink-200);
            background: #ffffff;
            font-size: 0.925rem;
            color: var(--ink-800);
            transition: border-color var(--transition-fast), box-shadow var(--transition-fast);
        }

        .form-input:focus {
            border-color: var(--brand-400);
            box-shadow: 0 0 0 3px rgba(59, 130, 246, 0.12);
            outline: none;
        }

        .form-input::placeholder {
            color: var(--ink-400);
        }

        select.form-input {
            appearance: none;
            background-image: url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' fill='none' viewBox='0 0 24 24' stroke='%2364748b' stroke-width='2'%3E%3Cpath stroke-linecap='round' stroke-linejoin='round' d='M19 9l-7 7-7-7'/%3E%3C/svg%3E");
            background-repeat: no-repeat;
            background-position: right 0.75rem center;
            background-size: 1rem;
            padding-right: 2.5rem;
        }

        /* 响应式 */
        @media (max-width: 1024px) {
            :root {
                --sidebar-width: 200px;
            }
            .page-container {
                padding-left: 1.5rem;
                padding-right: 1.5rem;
            }
        }

        @media (max-width: 768px) {
            .sidebar-nav {
                display: none;
            }
            .main-wrapper {
                margin-left: 0;
                padding-top: 56px;
            }
            .mobile-topbar {
                display: flex;
            }
            .page-container {
                padding-left: 1rem;
                padding-right: 1rem;
            }
            .section-title {
                font-size: 1.4rem;
            }
            .section-subtitle {
                font-size: 0.925rem;
            }
        }

        @media (max-width: 520px) {
            .page-container {
                padding-left: 0.75rem;
                padding-right: 0.75rem;
            }
            .section-title {
                font-size: 1.25rem;
            }
            .btn {
                padding: 0.5rem 1rem;
                font-size: 0.85rem;
            }
            .btn-lg {
                padding: 0.625rem 1.375rem;
                font-size: 0.925rem;
            }
            .countdown-unit {
                min-width: 52px;
                padding: 0.5rem 0.5rem;
            }
            .countdown-unit .countdown-number {
                font-size: 1.25rem;
            }
        }

        /* 底部固定转化条 */
        .floating-cta {
            position: fixed;
            bottom: 0;
            left: var(--sidebar-width);
            right: 0;
            background: #ffffff;
            border-top: 1px solid var(--ink-200);
            padding: 0.5rem 1.5rem;
            z-index: 35;
            display: flex;
            align-items: center;
            justify-content: space-between;
            gap: 1rem;
            box-shadow: 0 -4px 20px rgba(15, 23, 42, 0.08);
            transition: left var(--transition-slow);
        }

        @media (max-width: 768px) {
            .floating-cta {
                left: 0;
                padding: 0.5rem 0.75rem;
            }
        }