/* roulang page: index */
:root {
            --primary: #0A192F;
            --primary-teal: #0F2B3E;
            --accent: #0D9488;
            --accent-hover: #0F766E;
            --text-main: #0F172A;
            --text-sub: #334155;
            --text-light: #64748B;
            --bg-light: #F8FAFC;
            --card-shadow: 0 10px 25px -5px rgba(15, 23, 42, 0.05), 0 8px 10px -6px rgba(15, 23, 42, 0.04);
            --card-shadow-hover: 0 20px 30px -10px rgba(13, 148, 136, 0.15), 0 10px 15px -3px rgba(15, 23, 42, 0.08);
        }

        body {
            font-family: system-ui, -apple-system, "Segoe UI", Roboto, "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei", sans-serif;
            color: var(--text-main);
            background-color: #FFFFFF;
            overflow-x: hidden;
            letter-spacing: -0.01em;
            line-height: 1.75;
        }

        .hero-carousel-item {
            display: none;
            transition: opacity 0.6s ease-in-out;
        }
        .hero-carousel-item.active {
            display: block;
        }

        .feature-card {
            transition: all 0.3s cubic-bezier(0.4, 0, 0.2, 1);
            border: 1px solid #E2E8F0;
        }
        .feature-card:hover {
            transform: translateY(-4px);
            box-shadow: var(--card-shadow-hover);
            border-color: var(--accent);
        }

        .faq-content {
            max-height: 0;
            overflow: hidden;
            transition: max-height 0.35s ease-out, padding 0.35s ease;
        }
        .faq-item.active .faq-content {
            max-height: 240px;
            padding-bottom: 1.25rem;
        }
        .faq-item.active .faq-icon {
            transform: rotate(180deg);
        }

        .stat-glow {
            text-shadow: 0 2px 10px rgba(13, 148, 136, 0.25);
        }

        html {
            scroll-behavior: smooth;
        }