/* roulang page: index */
:root {
            --primary-navy: #0A2540;
            --accent-blue: #0969DA;
            --accent-cyan: #00D4B2;
            --text-dark: #0F172A;
            --text-muted: #475569;
            --border-light: #E2E8F0;
            --bg-canvas: #F8FAFC;
        }
        * {
            box-sizing: border-box;
            scroll-behavior: smooth;
        }
        body {
            font-family: system-ui, -apple-system, "Segoe UI", Roboto, "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei", sans-serif;
            background-color: var(--bg-canvas);
            color: var(--text-dark);
            overflow-x: hidden;
            line-height: 1.68;
        }
        .hero-banner-bg {
            background-image: linear-gradient(135deg, rgba(7, 22, 38, 0.94) 0%, rgba(10, 37, 64, 0.88) 100%), url('/assets/images/9cf885632537edc1.webp');
            background-size: cover;
            background-position: center;
        }
        .deep-space-bg {
            background-image: linear-gradient(180deg, rgba(7, 22, 38, 0.96) 0%, rgba(11, 19, 43, 0.98) 100%), url('/assets/images/ac10889dbe4795d5.webp');
            background-size: cover;
            background-position: center;
        }
        .card-hover-effect {
            transition: transform 0.25s cubic-bezier(0.16, 1, 0.3, 1), box-shadow 0.25s ease, border-color 0.25s ease;
        }
        .card-hover-effect:hover {
            transform: translateY(-4px);
            box-shadow: 0 12px 24px -6px rgba(10, 37, 64, 0.12);
            border-color: rgba(9, 105, 218, 0.4);
        }
        .accordion-content {
            transition: max-height 0.3s ease-out, opacity 0.3s ease;
            max-height: 0;
            overflow: hidden;
            opacity: 0;
        }
        .accordion-content.active {
            max-height: 500px;
            opacity: 1;
        }