:root {
    --primary-color: #ff4d4f; /* 搜狗红的现代变体 */
    --secondary-color: #1890ff;
    --text-main: #333;
    --text-light: #666;
    --bg-gray: #f8f9fa;
}

* { margin: 0; padding: 0; box-sizing: border-box; }
body { font-family: "PingFang SC", "Microsoft YaHei", sans-serif; line-height: 1.6; color: var(--text-main); }

/* Header & Footer */
header { background: #fff; box-shadow: 0 2px 10px rgba(0,0,0,0.05); position: sticky; top: 0; z-index: 1000; }
.nav-container { max-width: 1200px; margin: 0 auto; display: flex; justify-content: space-between; align-items: center; padding: 15px 20px; }
.logo { font-size: 24px; font-weight: bold; color: var(--primary-color); text-decoration: none; display: flex; align-items: center; }
.nav-links a { margin-left: 30px; text-decoration: none; color: #444; font-weight: 500; transition: 0.3s; }
.nav-links a:hover { color: var(--primary-color); }

footer { background: #222; color: #fff; padding: 60px 20px; margin-top: 50px; }
.footer-content { max-width: 1200px; margin: 0 auto; display: grid; grid-template-columns: repeat(4, 1fr); gap: 40px; }
.footer-bottom { text-align: center; padding-top: 40px; border-top: 1px solid #444; margin-top: 40px; font-size: 14px; color: #888; }

/* Components */
.btn-primary { background: var(--primary-color); color: #fff; padding: 12px 35px; border-radius: 25px; text-decoration: none; display: inline-block; font-weight: bold; transition: 0.3s; box-shadow: 0 4px 15px rgba(255,77,79,0.3); }
.btn-primary:hover { transform: translateY(-2px); box-shadow: 0 6px 20px rgba(255,77,79,0.4); }

/* Grid Layouts */
.container { max-width: 1200px; margin: 0 auto; padding: 0 20px; }
.section-title { text-align: center; margin: 50px 0; font-size: 32px; }