/* roulang page: index */
:root {
            --primary: #0F52BA;
            --primary-hover: #0b4194;
            --secondary: #0D9488;
            --accent: #F59E0B;
            --darkbase: #0F172A;
            --light-bg: #F8FAFC;
            --border-color: #E2E8F0;
        }
        body {
            font-family: -apple-system, BlinkMacSystemFont, "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei", sans-serif;
            background-color: #FFFFFF;
            color: #1E293B;
            overflow-x: hidden;
        }
        html {
            scroll-behavior: smooth;
        }
        .hero-video-mask {
            background: linear-gradient(180deg, rgba(15, 23, 42, 0.85) 0%, rgba(15, 23, 42, 0.95) 100%);
        }
        .card-hover {
            transition: all 0.25s cubic-bezier(0.4, 0, 0.2, 1);
        }
        .card-hover:hover {
            transform: translateY(-4px);
            box-shadow: 0 12px 24px -10px rgba(15, 82, 186, 0.15);
        }
        .tab-btn.active {
            background-color: #0F52BA;
            color: #FFFFFF;
            border-color: #0F52BA;
        }
        .accordion-content {
            transition: max-height 0.3s ease-out, opacity 0.3s ease-out;
            max-height: 0;
            opacity: 0;
            overflow: hidden;
        }
        .accordion-content.open {
            max-height: 500px;
            opacity: 1;
        }