/* roulang page: index */
:root {
            --primary: #1E40AF;
            --accent: #F97316;
            --secondary: #10B981;
            --dark: #0F172A;
            --text-main: #0F172A;
            --text-sub: #475569;
            --bg-light: #F8FAFC;
            --border-light: #E2E8F0;
        }
        * {
            box-sizing: border-box;
            margin: 0;
            padding: 0;
        }
        html {
            scroll-behavior: smooth;
            font-family: -apple-system, BlinkMacSystemFont, "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei", sans-serif;
            color: var(--text-main);
            background-color: #FFFFFF;
        }
        .code-container {
            font-family: ui-monospace, SFMono-Regular, Menlo, Monaco, Consolas, "Liberation Mono", "Courier New", monospace;
        }
        .bg-mesh-dark {
            background-color: #0F172A;
            background-image: radial-gradient(at 0% 0%, rgba(30, 64, 175, 0.4) 0px, transparent 50%),
                              radial-gradient(at 100% 100%, rgba(249, 115, 22, 0.25) 0px, transparent 50%);
        }
        .transition-all-200 {
            transition: all 0.2s cubic-bezier(0.4, 0, 0.2, 1);
        }