/* roulang page: index */
:root {
            --primary: #1A3038;
            --primary-dark: #0F1F24;
            --accent: #D97736;
            --secondary: #1D4A44;
            --bg-canvas: #F4F6F5;
            --text-main: #212529;
            --text-muted: #64748B;
            --border-light: rgba(226, 232, 240, 0.85);
        }
        body {
            font-family: system-ui, -apple-system, "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei", sans-serif;
            background-color: #FFFFFF;
            color: var(--text-main);
            line-height: 1.75;
            overflow-x: hidden;
        }
        .text-balance { text-wrap: balance; }
        .hero-diagonal-clip {
            clip-path: polygon(0 0, 100% 0, 100% 88%, 0 100%);
        }
        @media (max-width: 768px) {
            .hero-diagonal-clip { clip-path: none; }
        }
        .tab-btn.active {
            background-color: #1A3038;
            color: #FFFFFF;
            border-color: #1A3038;
        }
        .accordion-content {
            transition: max-height 0.3s cubic-bezier(0.4, 0, 0.2, 1);
            max-height: 0;
            overflow: hidden;
        }
        .accordion-content.expanded {
            max-height: 280px;
        }