/* roulang page: index */
:root {
            --primary: #0052D9;
            --primary-dark: #0A2540;
            --accent: #00D2FF;
            --cta: #FF6B00;
            --bg-light: #F8FAFC;
            --bg-night: #0B0F19;
            --text-main: #0F172A;
            --text-muted: #475569;
            --border-line: #E2E8F0;
        }
        html {
            scroll-behavior: smooth;
            font-family: -apple-system, BlinkMacSystemFont, "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei", "WenQuanYi Micro Hei", sans-serif;
        }
        .hero-bg {
            background-image: linear-gradient(135deg, rgba(10, 37, 64, 0.92) 0%, rgba(11, 15, 25, 0.96) 100%), url('/assets/images/a475cb9f29be4376.webp');
            background-size: cover;
            background-position: center;
        }
        .tech-dark-bg {
            background-image: linear-gradient(180deg, rgba(11, 15, 25, 0.97) 0%, rgba(10, 37, 64, 0.95) 100%), url('/assets/images/15d8a1699c8d4f88.webp');
            background-size: cover;
            background-position: center;
        }
        .glass-header {
            backdrop-filter: blur(12px);
            -webkit-backdrop-filter: blur(12px);
            background-color: rgba(255, 255, 255, 0.92);
        }
        .card-glow {
            transition: all 0.3s cubic-bezier(0.4, 0, 0.2, 1);
        }
        .card-glow:hover {
            transform: translateY(-4px);
            box-shadow: 0 12px 24px -10px rgba(0, 82, 217, 0.15), 0 0 0 1px rgba(0, 82, 217, 0.2);
        }
        .accordion-content {
            max-height: 0;
            overflow: hidden;
            transition: max-height 0.35s ease-out;
        }
        .accordion-item.active .accordion-content {
            max-height: 240px;
        }
        .accordion-item.active .accordion-icon {
            transform: rotate(180deg);
        }