/* roulang page: index */
:root {
            --primary: #D97706;
            --primary-glow: rgba(217, 119, 6, 0.25);
            --dark-base: #111215;
            --dark-card: #18191C;
            --text-title: #1F242D;
            --text-body: #4B5563;
            --bg-light: #F8F9FA;
            --border-ui: #E5E7EB;
        }
        html {
            scroll-behavior: smooth;
        }
        body {
            font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "Helvetica Neue", "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei", sans-serif;
            color: var(--text-body);
            background-color: #FFFFFF;
            overflow-x: hidden;
        }
        .text-glow {
            text-shadow: 0 0 20px rgba(245, 158, 11, 0.4);
        }
        .card-industrial {
            transition: transform 0.25s ease, box-shadow 0.25s ease, border-color 0.25s ease;
        }
        .card-industrial:hover {
            transform: translateY(-4px);
            box-shadow: 0 14px 30px rgba(0, 0, 0, 0.08);
            border-color: #F59E0B;
        }
        .dark-card-hover {
            transition: all 0.3s ease;
        }
        .dark-card-hover:hover {
            transform: translateY(-4px);
            box-shadow: 0 10px 30px rgba(217, 119, 6, 0.2);
            border-color: #D97706;
        }
        .hero-bg-overlay {
            background: linear-gradient(180deg, rgba(17, 18, 21, 0.88) 0%, rgba(17, 18, 21, 0.95) 100%);
        }
        /* 手风琴过渡 */
        .faq-content {
            max-height: 0;
            overflow: hidden;
            transition: max-height 0.35s ease-out;
        }
        .faq-content.open {
            max-height: 240px;
        }