顶栏

<nav class="nav nav--sticky" data-scroll-reactive>
  <div class="nav-left">
    <span class="demo-logo">◆ ICEN</span>
  </div>
  <div class="nav-center">
    <button class="nav-btn motion pressable focus-ring is-active">概览</button>
    <button class="nav-btn motion pressable focus-ring">文档</button>
    <button class="nav-btn motion pressable focus-ring">社区</button>
  </div>
  <div class="nav-right">
    <button class="nav-btn nav-btn--icon motion pressable focus-ring" aria-label="搜索">
      <svg viewBox="0 0 24 24" fill="none" stroke="currentColor" stroke-width="2" stroke-linecap="round"><circle cx="11" cy="11" r="7"/><path d="m20 20-3.5-3.5"/></svg>
    </button>
    <span class="nav-divider"></span>
    <button class="nav-btn motion pressable focus-ring">登录</button>
  </div>
</nav>