/* roulang page: index */
:root {
            --primary: #2563eb;
            --primary-dark: #1d4ed8;
            --text-main: #0f172a;
            --text-muted: #475569;
            --bg-light: #f8fafc;
            --border-light: #e2e8f0;
            --radius-md: 0.75rem;
            --shadow-card: 0 4px 20px -2px rgba(15, 23, 42, 0.06);
        }
        body {
            font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei", sans-serif;
            color: var(--text-main);
            background-color: var(--bg-light);
            overflow-x: hidden;
            scroll-behavior: smooth;
        }
        .custom-card-shadow {
            box-shadow: var(--shadow-card);
            transition: transform 0.25s ease, box-shadow 0.25s ease;
        }
        .custom-card-shadow:hover {
            transform: translateY(-4px);
            box-shadow: 0 12px 28px -4px rgba(37, 99, 235, 0.12);
        }
        details summary::-webkit-details-marker {
            display: none;
        }
        .video-tag-pulse {
            animation: pulse-ring 2s cubic-bezier(0.4, 0, 0.6, 1) infinite;
        }
        @keyframes pulse-ring {
            0%, 100% { opacity: 1; transform: scale(1); }
            50% { opacity: 0.85; transform: scale(1.05); }
        }