/* ============================================================================
 * platform-pc/css/app.css — PC 端布局（侧边导航 + 顶栏 + 内容区）
 * ========================================================================== */
#lesu-app { display: flex; min-height: 100vh; }

/* 侧边导航 */
.lesu-nav {
  width: 208px; flex: none; background: var(--panel); border-right: 1px solid var(--border);
  display: flex; flex-direction: column; padding: 14px 10px; gap: 2px; position: sticky; top: 0; height: 100vh; overflow: auto;
}
.lesu-nav__brand { display: flex; align-items: center; gap: 8px; font-weight: 700; font-size: 14px; padding: 6px 10px 16px; }
.lesu-nav__brand .dot { width: 9px; height: 9px; border-radius: 50%; background: var(--primary); flex: none; }
.lesu-nav a { display: block; padding: 8px 12px; border-radius: 6px; color: var(--text-2); font-size: 13px; }
.lesu-nav a:hover { background: var(--panel-2); color: var(--text); }
.lesu-nav a.active { background: var(--primary); color: #fff; }
.lesu-nav__foot { margin-top: auto; padding: 10px 12px 0; font-size: 11px; color: var(--text-2); border-top: 1px solid var(--border); }

/* 主区 */
.lesu-main { flex: 1; min-width: 0; display: flex; flex-direction: column; }
.lesu-topbar {
  height: 54px; flex: none; border-bottom: 1px solid var(--border); background: var(--panel);
  display: flex; align-items: center; justify-content: space-between; padding: 0 18px; gap: 14px;
  position: sticky; top: 0; z-index: 100;
}
.lesu-topbar__left, .lesu-topbar__right { display: flex; align-items: center; gap: 10px; }
.lesu-switcher { display: flex; align-items: center; gap: 8px; }
.lesu-switcher > span { font-size: 12px; color: var(--text-2); }
.lesu-switcher select {
  padding: 6px 10px; border: 1px solid var(--primary); border-radius: 6px;
  background: var(--panel-2); color: var(--text); font-size: 13px; min-width: 240px; max-width: 340px;
}
.lesu-badge { font-size: 11px; color: var(--text-2); border: 1px solid var(--border); border-radius: 20px; padding: 3px 9px; }
.lesu-user { font-size: 13px; display: flex; align-items: center; gap: 6px; }
.lesu-user i { font-style: normal; font-size: 11px; color: var(--text-2); border: 1px solid var(--border); border-radius: 20px; padding: 2px 7px; }
.lesu-content { flex: 1; padding: 20px; overflow: auto; }

@media (max-width: 1080px) {
  .lesu-split { grid-template-columns: 1fr; }
  .lesu-nav { width: 168px; }
  .lesu-switcher select { min-width: 160px; }
}