* { margin:0; padding:0; box-sizing:border-box; -webkit-tap-highlight-color:transparent; }
body { background-color: #221f1f; color: #fff; font-family: -apple-system, system-ui, BlinkMacSystemFont, "Segoe UI", Roboto, sans-serif; display: flex; justify-content: center; padding: 40px 20px; }
.wrapper { width: 100%; max-width: 500px; text-align: center; }

h1 { font-size: 50px; font-weight: bold; margin-bottom: 5px; letter-spacing: 2px; }
.sub1 { font-size: 17px; color: #bbb; margin-bottom: 5px; }
.sub2 { font-size: 18px; color: #fff; font-weight: 500; margin-bottom: 30px; word-spacing: 10px; }

/* 线路按钮样式 */
.main-item { background: #333; border-radius: 16px; padding: 18px; margin-bottom: 15px; display: block; text-decoration: none; border: 1px solid #3a3a3a; transition: 0.2s; }
.main-item:active { background: #444; transform: scale(0.98); }
.main-item .n { font-size: 18px; color: #fff; display: block; margin-bottom: 2px; }
.main-item .u { font-size: 16px; color: #ff4d6d; display: block; font-weight: bold; }

/* 并排按钮 */
.btn-group { display: flex; gap: 12px; margin-top: 5px; }
.btn-small { flex: 1; background: #333; padding: 22px 10px; border-radius: 16px; color: #fff; text-decoration: none; font-size: 16px; border: 1px solid #3a3a3a; font-weight: 500; }

/* 横幅广告位 */
.banner { margin-top: 20px; background: #000; border-radius: 16px; overflow: hidden; position: relative; padding: 25px 15px; border: 1px solid #3a3a3a; }
.banner-bg { position: absolute; top:0; left:0; width:100%; height:100%; object-fit: cover; opacity: 0.2; z-index: 1; }
.banner-content { position: relative; z-index: 2; font-size: 15px; line-height: 1.6; }
.banner-content a { color: #ff4d6d; text-decoration: underline; font-weight: bold; }

/* 底部图标导航 */
.social-grid { display: grid; grid-template-columns: repeat(5, 1fr); gap: 5px; margin-top: 35px; }
.social-item { text-decoration: none; color: #ccc; font-size: 11px; }
.icon-box { background: #3a3a3a; width: 46px; height: 46px; border-radius: 50%; margin: 0 auto 10px; display: flex; align-items: center; justify-content: center; transition: 0.2s; }
.social-item img { width: 22px; height: 22px; filter: invert(1); } /* 图标自动转为白色 */

/* 页脚 */
footer { margin-top: 60px; font-size: 12px; color: #777; line-height: 1.8; }
footer a { color: #ff4d6d; text-decoration: none; }

/* 电脑端优化 */
@media (min-width: 768px) {
    .wrapper { max-width: 550px; }
}