/* roulang page: index */
:root {
            --primary: #0F52BA;
            --primary-dark: #0A387E;
            --secondary: #059669;
            --accent: #D97706;
            --dark: #0B132B;
            --slate: #0F172A;
            --body-text: #334155;
            --muted-text: #64748B;
            --bg-light: #F8FAFC;
        }
        html {
            scroll-behavior: smooth;
            font-family: system-ui, -apple-system, "PingFang SC", "Microsoft YaHei", sans-serif;
        }
        body {
            color: var(--body-text);
            background-color: var(--bg-light);
            line-height: 1.75;
        }
        .container-custom {
            max-width: 1200px;
            margin-left: auto;
            margin-right: auto;
            padding-left: 1.25rem;
            padding-right: 1.25rem;
        }
        .hero-bg {
            background: linear-gradient(135deg, rgba(11, 19, 43, 0.95) 0%, rgba(15, 82, 186, 0.88) 100%), url('/assets/images/d09ff729d750a282.webp') center/cover no-repeat;
        }
        .dark-tech-bg {
            background: linear-gradient(180deg, #0B132B 0%, #111C44 100%), url('/assets/images/4d95c066df8d20d1.webp') center/cover no-repeat;
        }
        .card-shadow {
            box-shadow: 0 4px 6px -1px rgba(0, 0, 0, 0.05), 0 2px 4px -2px rgba(0, 0, 0, 0.05);
            transition: all 0.3s cubic-bezier(0.4, 0, 0.2, 1);
        }
        .card-shadow:hover {
            transform: translateY(-4px);
            box-shadow: 0 16px 25px -5px rgba(15, 82, 186, 0.1), 0 8px 10px -6px rgba(15, 82, 186, 0.08);
        }
        .tab-btn.active {
            color: #0F52BA;
            border-bottom: 2px solid #0F52BA;
            background-color: rgba(15, 82, 186, 0.04);
            font-weight: 600;
        }
        .tab-content {
            display: none;
        }
        .tab-content.active {
            display: grid;
        }
        .accordion-content {
            max-height: 0;
            overflow: hidden;
            transition: max-height 0.35s ease-out;
        }
        .accordion-item.open .accordion-content {
            max-height: 280px;
        }
        .accordion-item.open .accordion-icon {
            transform: rotate(180deg);
        }