/* 场景容器 */
.scene { display:none; position:absolute; top:0; left:0; right:0; bottom:60px; }
.scene.active { display:flex; flex-direction:column; }

/* 底部导航 */
.bottom-nav {
  position: absolute; bottom:0; left:0; right:0;
  height: 60px;
  background: rgba(10,10,26,0.95);
  border-top: 1px solid var(--border);
  display: flex;
  z-index: 100;
  backdrop-filter: blur(10px);
}
.nav-btn {
  flex:1;
  display:flex; flex-direction:column; align-items:center; justify-content:center;
  background:none; border:none; color:var(--text2);
  font-size:11px; cursor:pointer; transition:color 0.2s;
  gap: 2px;
}
.nav-btn .nav-icon { font-size:22px; }
.nav-btn.active { color:var(--accent); }
.nav-btn:active { opacity:0.7; }