* { box-sizing: border-box; }
        body {
            max-width: 920px;
            margin: 0 auto;
            padding: 56px 40px 80px;
            color: #303B45;
            background: #fff;
            font-family: "Microsoft YaHei", Arial, sans-serif;
            font-size: 16px;
            line-height: 1.9;
        }
        h1 {
            margin: 0 0 24px;
            padding-bottom: 18px;
            border-bottom: 3px solid var(--primary-color);
            color: #25343D;
            font-size: 32px;
            line-height: 1.35;
        }
        h2, h3 { color: #25343D; }
        p { margin: 8px 0; }
        a { color: var(--secondary-color, var(--primary-color)); }
        img { max-width: 100%; height: auto; }
        table { max-width: 100%; border-collapse: collapse; }
        th, td { padding: 10px; border: 1px solid #E4EAEA; }
        @media (max-width: 640px) {
            body { padding: 32px 20px 56px; font-size: 15px; }
            h1 { font-size: 26px; }
        }