/* roulang page: index */
:root {
            --brand-primary: #581C87;
            --brand-cyber: #7E22CE;
            --brand-cyan: #06B6D4;
            --bg-deep: #0F0728;
            --text-heading: #0F172A;
            --text-body: #334155;
            --text-muted: #64748B;
            --border-light: #E2E8F0;
        }

        html {
            scroll-behavior: smooth;
            font-family: system-ui, -apple-system, "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei", sans-serif;
            color: var(--text-body);
            background-color: #F8FAFC;
        }

        body {
            line-height: 1.8;
            margin: 0;
            padding: 0;
        }

        h1, h2, h3, h4, h5, h6 {
            letter-spacing: -0.02em;
            color: var(--text-heading);
            font-weight: 700;
        }

        .hero-pattern {
            background-image: linear-gradient(135deg, rgba(15, 7, 40, 0.92) 0%, rgba(88, 28, 135, 0.88) 100%), url('/assets/images/2880f5d7354e9955.webp');
            background-size: cover;
            background-position: center;
        }

        .dark-section {
            background-color: var(--bg-deep);
            background-image: radial-gradient(circle at 50% 0%, #1e0d42 0%, #0F0728 75%);
        }

        .card-hover {
            transition: all 0.3s cubic-bezier(0.4, 0, 0.2, 1);
        }
        .card-hover:hover {
            transform: translateY(-6px);
            box-shadow: 0 20px 25px -5px rgba(0, 0, 0, 0.08), 0 10px 10px -5px rgba(0, 0, 0, 0.04);
        }

        .cyan-glow:hover {
            box-shadow: 0 0 25px rgba(6, 182, 212, 0.45);
        }

        .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);
        }