/* roulang page: index */
:root {
            --primary-black: #0D0F12;
            --surface-card: #161920;
            --neon-accent: #00FF88;
            --text-main: #F1F5F9;
            --text-sub: #94A3B8;
            --border-line: #222630;
        }
        body {
            font-family: -apple-system, BlinkMacSystemFont, "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei", "Segoe UI", Roboto, sans-serif;
            background-color: var(--primary-black);
            color: var(--text-main);
            overflow-x: hidden;
            scroll-behavior: smooth;
        }
        .container-custom {
            max-width: 1280px;
            margin-left: auto;
            margin-right: auto;
            padding-left: 24px;
            padding-right: 24px;
        }
        .glass-header {
            background: rgba(13, 15, 18, 0.85);
            backdrop-filter: blur(16px);
            -webkit-backdrop-filter: blur(16px);
            border-bottom: 1px solid var(--border-line);
        }
        .neon-btn {
            background-color: var(--neon-accent);
            color: #050608;
            font-weight: 700;
            transition: all 0.3s cubic-bezier(0.16, 1, 0.3, 1);
        }
        .neon-btn:hover {
            box-shadow: 0 0 25px rgba(0, 255, 136, 0.45);
            transform: translateY(-2px);
        }
        .neon-outline-btn {
            border: 1px solid var(--neon-accent);
            color: var(--neon-accent);
            transition: all 0.3s cubic-bezier(0.16, 1, 0.3, 1);
        }
        .neon-outline-btn:hover {
            background: rgba(0, 255, 136, 0.1);
            color: #FFFFFF;
        }
        .feature-card {
            background: #14171E;
            border: 1px solid var(--border-line);
            border-radius: 16px;
            transition: all 0.3s ease;
        }
        .feature-card:hover {
            border-color: rgba(0, 255, 136, 0.3);
            transform: translateY(-4px);
            box-shadow: 0 16px 36px rgba(0, 0, 0, 0.4);
        }
        .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);
        }