:root{
  --nav-bg:#1e2a44;
  --nav-text:#e8eefc;
  --white:#ffffff;
  --muted:#c0c6d4;
  --btn:#2b8cff;
  --btn-hover:#1674ec;
  --shadow:rgba(0,0,0,.35);
}

*{box-sizing:border-box}
html,body{height:100%}
body{margin:0;font-family:-apple-system,BlinkMacSystemFont,"Segoe UI",Roboto,"PingFang SC","Microsoft YaHei",sans-serif;color:#0f172a;background:#0b0f1a}

/* 顶栏 */
.topbar{height:64px;background:var(--nav-bg);color:var(--nav-text);display:flex;align-items:center;justify-content:space-between;padding:0 24px}
.topbar__left{display:flex;align-items:center;gap:12px}
.logo{height:28px}
.brand{line-height:1.1}
.brand__title{font-size:14px;opacity:.9}
.brand__subtitle{font-size:12px;opacity:.8}
.btn{display:inline-flex;align-items:center;justify-content:center;height:32px;padding:0 14px;border-radius:16px;border:1px solid rgba(255,255,255,.35);color:var(--white);text-decoration:none}
.btn--ghost:hover{background:rgba(255,255,255,.1)}

/* 英雄区背景 */
.hero{position:relative;min-height:calc(100vh - 64px - 56px);}
.hero__bg{position:absolute;inset:0;background-image:var(--hero-url);background-size:cover;background-position:center center;filter:saturate(1.05)}
.hero__overlay{position:absolute;inset:0;background:rgba(10,16,30,.35)}

/* 搜索框 */
.search{position:relative;z-index:1;display:flex;flex-direction:column;align-items:center;gap:12px;padding-top:28vh}
.search__label{color:#fff;font-size:18px;text-shadow:0 2px 8px var(--shadow)}
.search__row{display:flex;width:min(680px,90%);height:44px;border-radius:24px;overflow:hidden;box-shadow:0 8px 24px var(--shadow)}
.search__input{flex:1;padding:0 16px;border:none;outline:none;font-size:14px}
.search__btn{width:56px;border:none;background:var(--btn);color:#fff;cursor:pointer}
.search__btn:hover{background:var(--btn-hover)}

/* 页脚 */
.footer{height:56px;display:flex;align-items:center;justify-content:center;background:#fff}
.footer__text{color:#6b7280;font-size:12px;text-align:center;padding:0 12px}

/* 响应式 */
@media (max-width:768px){
  .brand__title{font-size:13px}
  .brand__subtitle{font-size:11px}
  .search{padding-top:16vh}
  .search__row{height:42px}
  .search__btn{width:52px}
}