/* ══════════════════════════════════════
   左侧导航栏 (nav-sidebar)
   样式仅作用于 .nav-sidebar 内，不污染全局
   ══════════════════════════════════════ */

.nav-sidebar {
  background: var(--side-bg);
  border-right: 1px solid var(--border-color);
  display: flex;
  flex-direction: column;
  overflow: hidden;
}

/* 可滚动区域 */
.nav-scroll {
  flex: 1;
  overflow-y: auto;
  padding: 12px 10px 16px;
  display: flex;
  flex-direction: column;
  gap: 4px;
}

/* ── Section 标题 ── */
.nav-section-label {
  padding: 8px 10px 4px;
  font-size: 10px;
  font-weight: 700;
  color: var(--text-secondary);
  text-transform: uppercase;
  letter-spacing: 0.08em;
}

/* ── 一级导航按钮 ── */
.nav-item {
  display: flex;
  align-items: center;
  gap: 9px;
  padding: 9px 10px;
  border-radius: 8px;
  border: none;
  background: transparent;
  color: var(--text-secondary);
  font-size: 13px;
  font-weight: 500;
  cursor: pointer;
  width: 100%;
  text-align: left;
  transition: background 0.15s, color 0.15s;
  position: relative;
}

.nav-item .material-symbols-rounded {
  font-size: 18px;
  flex-shrink: 0;
}

.nav-item:hover {
  background: var(--hover-bg);
  color: var(--text-primary);
}

.nav-item.active {
  background: rgba(83,155,245,0.12);
  color: var(--accent-blue);
}

/* 下拉箭头 */
.nav-item .nav-arrow {
  margin-left: auto;
  font-size: 16px !important;
  transition: transform 0.2s;
  flex-shrink: 0;
}

.nav-item.open .nav-arrow {
  transform: rotate(180deg);
}

/* ── 二级子菜单 ── */
.nav-sub {
  overflow: hidden;
  max-height: 0;
  transition: max-height 0.25s ease;
}

.nav-sub.open {
  max-height: 400px;
}

/* History 下拉展开时支持滚动 */
#nav-sub-history.open {
  overflow-y: auto;
  max-height: 320px;
}

.nav-sub-item {
  display: flex;
  align-items: center;
  gap: 8px;
  padding: 7px 10px 7px 34px;
  border-radius: 8px;
  border: none;
  background: transparent;
  color: var(--text-secondary);
  font-size: 13px;
  cursor: pointer;
  width: 100%;
  text-align: left;
  transition: background 0.15s, color 0.15s;
}

.nav-sub-item .material-symbols-rounded {
  font-size: 16px;
  flex-shrink: 0;
}

.nav-sub-item:hover {
  background: var(--hover-bg);
  color: var(--text-primary);
}

.nav-sub-item.active {
  background: rgba(83,155,245,0.12);
  color: var(--accent-blue);
}

/* ── History 历史记录列表（左侧展开）── */
/* 样式参考 前端参考.html */
.nav-history-list {
  display: flex;
  flex-direction: column;
  gap: 8px;
  padding: 4px 4px 4px 8px;
}

.nav-history-empty {
  padding: 8px 10px 8px 34px;
  font-size: 12px;
  color: var(--text-secondary);
}

/* 参考 前端参考.html .history-item */
.history-item {
  display: flex;
  justify-content: space-between;
  align-items: center;
  padding: 10px 10px;
  border-radius: 8px;
  border: 1px solid var(--border-color);
  background: rgba(255,255,255,0.02);
  font-size: 12px;
  gap: 8px;
  transition: border-color 0.15s;
}

.history-item:hover {
  border-color: rgba(83,155,245,0.4);
}

.history-item-info {
  flex: 1;
  min-width: 0;
  display: flex;
  flex-direction: column;
  gap: 3px;
}

.history-item-title {
  font-size: 12px;
  font-weight: 600;
  color: var(--text-primary);
  white-space: nowrap;
  overflow: hidden;
  text-overflow: ellipsis;
}

/* 参考 前端参考.html .history-meta */
.history-meta {
  display: flex;
  align-items: center;
  gap: 6px;
  color: var(--text-secondary);
  font-size: 11px;
  flex-wrap: wrap;
}

/* 参考 前端参考.html .pill */
.hist-pill {
  padding: 2px 6px;
  border-radius: 5px;
  border: 1px solid var(--border-color);
  font-size: 10px;
  font-weight: 600;
  white-space: nowrap;
}

.history-item-actions {
  display: flex;
  gap: 4px;
  flex-shrink: 0;
}

.hist-btn {
  display: flex;
  align-items: center;
  justify-content: center;
  width: 26px;
  height: 26px;
  border-radius: 6px;
  border: 1px solid var(--border-color);
  background: transparent;
  color: var(--text-secondary);
  cursor: pointer;
  transition: background 0.15s, color 0.15s, border-color 0.15s;
}

.hist-btn .material-symbols-rounded { font-size: 14px; }

.hist-btn.view:hover {
  background: rgba(83,155,245,0.12);
  color: var(--accent-blue);
  border-color: var(--accent-blue);
}

.hist-btn.del:hover {
  background: rgba(248,81,73,0.1);
  color: var(--danger);
  border-color: var(--danger);
}

/* ── 底部分隔 ── */
.nav-divider {
  height: 1px;
  background: var(--border-color);
  margin: 6px 10px;
}