/* ========== 移动端抽屉侧边栏 ========== */
.mobile-sidebar {
  position: fixed;
  top: 0;
  left: 0;
  bottom: 0;
  width: 280px;
  max-width: 80vw;
  z-index: 99999;
  background: var(--md-sys-color-surface);
  transform: translateX(-100%);
  transition: transform 0.25s cubic-bezier(0.2, 0, 0, 1);
  display: flex;
  flex-direction: column;
  border-radius: 0 24px 24px 0;
  box-shadow: 0 0 20px rgba(0,0,0,0.15);
  overflow: hidden;
  padding-bottom: max(20px, env(safe-area-inset-bottom));
  box-sizing: border-box;
}

.mobile-sidebar.show {
  transform: translateX(0);
}

.mobile-sidebar-header {
  padding: 20px 20px 12px;
  font-size: 16px;
  font-weight: 500;
  color: var(--md-sys-color-on-surface);
  display: flex;
  justify-content: space-between;
  align-items: center;
}

.mobile-sidebar-body {
  flex: 1;
  overflow-y: auto;
  padding: 8px 12px;
  padding-bottom: 16px;
}

.mobile-sidebar-footer {
  padding: 12px 16px;
  padding-bottom: calc(16px + env(safe-area-inset-bottom));
  border-top: 1px solid var(--md-sys-color-outline-variant);
}
.mobile-sidebar-item {
    display: flex;
    align-items: center;
    justify-content: space-between;
    padding: 12px 16px;
    border-radius: 16px;
    cursor: pointer;
    font-size: 15px;
    transition: background 0.15s ease;
}
.mobile-sidebar-item span {
    white-space: nowrap;
    overflow: hidden;
    text-overflow: ellipsis;
    flex: 1;
    margin-right: 8px;
}
.mobile-sidebar-item.active {
    background: var(--md-sys-color-primary-container);
    color: var(--md-sys-color-on-primary-container);
    font-weight: 500;
}
.mobile-sidebar-backdrop {
    position: fixed;
    inset: 0;
    background: rgba(0, 0, 0, 0.3);
    z-index: 99998;
    opacity: 0;
    pointer-events: none;
    transition: opacity 0.25s ease;
}
.mobile-sidebar-backdrop.show {
    opacity: 1;
    pointer-events: auto;
}

/* ========== 媒体查询 ========== */
/* 移动端 768px 以下 */
@media (max-width: 768px) {
    .sidebar { display: none; }
    .mobile-group-toggle { display: flex; }
    .action-bar { flex-direction: column; align-items: stretch; }
    .search-field { width: 100%; }
    .doc-grid { grid-template-columns: 1fr; }
    .tabs-container { flex-direction: column; align-items: stretch; }
    .tabs-wrapper { justify-content: space-between; }
    .group-dropdown {
        top: 180px;
        right: 16px;
        left: 16px;
        min-width: auto;
    }
}

/* PC 端隐藏移动端按钮 */
@media (min-width: 768px) {
    .mobile-group-toggle { display: none !important; }
}

/* 平板横屏优化 */
@media (max-width: 1024px) and (orientation: landscape) {
    .sidebar-item.active {
        background: var(--md-sys-color-primary-container) !important;
        color: var(--md-sys-color-on-primary-container) !important;
        font-weight: 600 !important;
        box-shadow: var(--md-sys-elevation-level1) !important;
    }
    .mobile-group-toggle { display: flex; }
}