.app-shell{max-width:430px;min-height:100vh;margin:0 auto;position:relative;overflow:hidden}.bottom-nav{z-index:100;background:#fff;border-top:1px solid #e5e7eb;width:100%;max-width:430px;height:64px;display:flex;position:fixed;bottom:0;left:50%;transform:translate(-50%)}.bottom-nav button{cursor:pointer;background:0 0;border:none;flex-direction:column;flex:1;justify-content:center;align-items:center;gap:4px;display:flex}.bottom-nav button.active{color:#007aff}