/* roulang page: index */
:root {
            --primary: #2B303A;
            --accent: #E65F2B;
            --bg-light: #F8F9FA;
            --bg-mortar: #EEF0F2;
            --bg-dark: #1A1C20;
            --text-main: #1E2229;
            --text-muted: #5C6470;
            --border-line: #DCE0E5;
        }
        * { box-sizing: border-box; }
        html { scroll-behavior: smooth; }
        body {
            font-family: -apple-system, BlinkMacSystemFont, "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei", sans-serif;
            color: var(--text-main);
            background-color: var(--bg-light);
            line-height: 1.7;
            overflow-x: hidden;
        }
        .hero-pattern {
            background-image: linear-gradient(rgba(26, 28, 32, 0.88), rgba(26, 28, 32, 0.94)), url('/assets/images/498d86f12432fafd.webp');
            background-size: cover;
            background-position: center;
        }
        .blueprint-bg {
            background-image: radial-gradient(rgba(230, 95, 43, 0.12) 1px, transparent 1px);
            background-size: 24px 24px;
        }
        .accordion-content {
            max-height: 0;
            overflow: hidden;
            transition: max-height 0.35s ease-out, padding 0.35s ease;
        }
        .accordion-content.active {
            max-height: 280px;
        }