/* roulang page: index */
:root {
            --primary: #0f766e;
            --primary-light: #14b8a6;
            --primary-dark: #042f2e;
            --surface-bg: #f8fafc;
            --text-main: #0f172a;
            --text-body: #334155;
            --text-sub: #64748b;
            --border-color: #e2e8f0;
        }
        body {
            font-family: -apple-system, BlinkMacSystemFont, "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei", sans-serif;
            background-color: var(--surface-bg);
            color: var(--text-body);
            -webkit-font-smoothing: antialiased;
        }
        .header-glass {
            background-color: rgba(255, 255, 255, 0.95);
            backdrop-filter: blur(10px);
        }
        .hero-banner {
            background: linear-gradient(135deg, rgba(4, 47, 46, 0.92) 0%, rgba(15, 23, 42, 0.88) 100%), url('/assets/images/d3d347fa3f9bdaa6.webp') center/cover no-repeat;
        }
        .section-dark {
            background: linear-gradient(180deg, #042f2e 0%, #0f172a 100%);
        }
        .card-custom {
            transition: all 0.3s cubic-bezier(0.4, 0, 0.2, 1);
        }
        .card-custom:hover {
            transform: translateY(-4px);
            box-shadow: 0 12px 24px -10px rgba(15, 118, 110, 0.18);
        }
        .faq-chevron {
            transition: transform 0.3s ease;
        }
        .faq-item.active .faq-chevron {
            transform: rotate(180deg);
        }
        .faq-item.active .faq-content {
            display: block;
        }
        .tab-btn.active {
            background-color: #0f766e;
            color: #ffffff;
            border-color: #0f766e;
        }
        .slide-item {
            display: none;
            opacity: 0;
            transition: opacity 0.6s ease-in-out;
        }
        .slide-item.active {
            display: block;
            opacity: 1;
        }