.sidebar {
      width: var(--sidebar-width);
      flex-shrink: 0;
      background: var(--settings-bg);
      backdrop-filter: blur(20px);
      -webkit-backdrop-filter: blur(20px);
      border-radius: var(--border-radius);
      border: 1px solid rgba(255, 255, 255, 0.08);
      box-shadow: var(--shadow-light);
      display: flex;
      flex-direction: column;
      overflow: hidden;
      min-width: 0;
      position: relative;
      clip-path: inset(0 round var(--border-radius));
      transition: width 0.3s cubic-bezier(0.4, 0, 0.2, 1);
      will-change: width;
    }

    .sidebar.collapsed {
      width: 0;
      border: none;
      padding: 0;
      opacity: 0;
      visibility: hidden;
      backdrop-filter: none;
      -webkit-backdrop-filter: none;
    }

    .collapse-sidebar-btn {
      width: 28px; height: 28px; display: flex; align-items: center; justify-content: center;
      background: none; border: none; color: var(--text-secondary); cursor: pointer;
      border-radius: 6px; transition: all 0.2s; flex-shrink: 0;
    }
    .collapse-sidebar-btn:hover { background: rgba(255,255,255,0.08); color: var(--text-primary); }
    .expand-sidebar-btn {
      width: 36px; height: 36px; display: flex; align-items: center; justify-content: center;
      background: rgba(255,255,255,0.06); border: 1px solid rgba(255,255,255,0.1);
      border-radius: 8px; color: var(--text-primary); cursor: pointer; transition: background 0.2s;
      margin-right: auto;
    }
    .expand-sidebar-btn:hover { background: rgba(255,255,255,0.12); }

    /* 折叠按钮样式 */
    .sidebar-collapse-btn {
      width: 24px;
      height: 24px;
      display: flex;
      align-items: center;
      justify-content: center;
      border-radius: 4px;
      background: transparent;
      border: none;
      color: var(--text-secondary);
      cursor: pointer;
      transition: all 0.2s ease;
      font-size: 0.8rem;
    }

    .sidebar-collapse-btn:hover {
      background: rgba(255,255,255,0.1);
      color: var(--text-primary);
    }

    /* 汉堡按钮（在 chat-header 中） */
    .hamburger-btn {
      width: 40px;
      height: 40px;
      display: flex;
      align-items: center;
      justify-content: center;
      background: rgba(255,255,255,0.06);
      border: 1px solid rgba(255,255,255,0.1);
      border-radius: 10px;
      color: var(--text-primary);
      cursor: pointer;
      transition: background 0.2s;
      flex-shrink: 0;
    }
    .hamburger-btn:hover { background: rgba(255,255,255,0.12); }

    .sidebar-header {
      padding: 16px;
      background: rgba(var(--glass-color-rgb), 0.6);
      border-bottom: 1px solid rgba(255,255,255,0.06);
      display: flex;
      justify-content: space-between;
      align-items: center;
    }

    .sidebar-search {
      display: flex; align-items: center; gap: 8px;
      margin: 10px 10px 6px; padding: 9px 14px;
      background: rgba(255,255,255,0.06); border-radius: 20px;
      color: var(--text-secondary); font-size: 0.82rem; cursor: pointer;
      transition: background 0.2s;
    }
    .sidebar-search:hover { background: rgba(255,255,255,0.1); }

    .sidebar-title {
      font-size: 1rem;
      font-weight: 600;
      color: var(--accent-color);
      letter-spacing: 1px;
    }

    .sidebar-actions {
      display: flex;
      gap: 8px;
    }

    .sidebar-btn {
      width: 28px;
      height: 28px;
      display: flex;
      align-items: center;
      justify-content: center;
      border-radius: 6px;
      background: rgba(255,255,255,0.1);
      border: 1px solid rgba(255,255,255,0.2);
      color: #ffffff;
      cursor: pointer;
      font-size: 0.9rem;
      transition: all 0.2s ease;
    }

    .sidebar-btn:hover {
      background: rgba(162,155,254,0.2);
      border-color: rgba(162,155,254,0.4);
    }

    .sidebar-section {
      flex: 1;
      overflow-y: auto;
      overflow-x: hidden;
      padding: 8px;
    }

    .section-label {
      font-size: 0.7rem;
      font-weight: 600;
      color: var(--text-secondary);
      text-transform: uppercase;
      letter-spacing: 1px;
      padding: 8px 8px 4px;
    }

    .chat-list {
      display: flex;
      flex-direction: column;
      gap: 4px;
    }

    .chat-list-item {
      display: flex;
      align-items: center;
      gap: 10px;
      padding: 10px;
      border-radius: 8px;
      cursor: pointer;
      transition: all 0.2s ease;
      background: transparent;
      overflow: visible;
      min-width: 0;
      position: relative;
    }

    .chat-list-item:hover {
      background: rgba(255,255,255,0.08);
    }

    .chat-list-item.active {
      background: rgba(162,155,254,0.15);
      border: 1px solid rgba(162,155,254,0.3);
    }

    .chat-list-item-avatar {
      width: 36px;
      height: 36px;
      border-radius: 50%;
      display: flex;
      align-items: center;
      justify-content: center;
      font-size: 1.2rem;
      background: rgba(0,0,0,0.3);
      flex-shrink: 0;
      overflow: hidden;
    }
    .chat-list-item-avatar img {
      width: 100%;
      height: 100%;
      object-fit: cover;
    }

    .chat-list-item-info {
      flex: 1;
      min-width: 0;
    }

    .chat-list-item-name {
      font-size: 0.85rem;
      font-weight: 500;
      color: var(--text-primary);
      white-space: nowrap;
      overflow: hidden;
      text-overflow: ellipsis;
    }

    .chat-list-item-preview {
      font-size: 0.7rem;
      color: var(--text-secondary);
      white-space: nowrap;
      overflow: hidden;
      text-overflow: ellipsis;
      margin-top: 2px;
    }
    /* 未读消息角标 */
    .unread-badge { position: absolute; top: 4px; right: 4px; min-width: 18px; height: 18px; border-radius: 9px; background: var(--accent-color); color: #fff; font-size: 0.6rem; font-weight: 600; display: flex; align-items: center; justify-content: center; padding: 0 5px; box-shadow: 0 2px 6px rgba(0,0,0,0.3); z-index: 2; }


    /* 侧边栏标题栏 */
    .sidebar-header-bar { display: flex; align-items: center; justify-content: flex-end; padding: 14px 12px 6px; position: relative; overflow: hidden; min-width: 0; }
    .sidebar-title { position: absolute; left: 50%; transform: translateX(-50%); font-size: 1.05rem; font-weight: 600; color: #ffffff; letter-spacing: 1px; white-space: nowrap; }
    .sidebar-search-row { display: flex; align-items: center; gap: 8px; padding: 4px 10px 8px; overflow: hidden; min-width: 0; }
    .sidebar-search-row .sidebar-search { flex: 1; margin: 0; }

    /* Telegram 风格汉堡菜单弹窗 */
    .nav-drawer-overlay { position: fixed; inset: 0; z-index: 250; pointer-events: none; }
    .nav-drawer-overlay.show { pointer-events: auto; }
    .nav-drawer { position: fixed; width: 260px; max-width: calc(100vw - 32px); max-height: calc(100vh - 80px); background: var(--settings-bg); backdrop-filter: blur(20px); -webkit-backdrop-filter: blur(20px); border: 1px solid rgba(255,255,255,0.08); border-radius: 10px; z-index: 300; flex-direction: column; box-shadow: 0 4px 20px rgba(0,0,0,0.4); overflow: hidden; transform-origin: top left; will-change: transform, opacity; visibility: hidden; opacity: 0; transform: scale(0.9); pointer-events: none; transition: opacity 0.15s ease, transform 0.15s ease, visibility 0s linear 0.15s; }
    .nav-drawer.open { visibility: visible; opacity: 1; transform: scale(1); pointer-events: auto; transition: opacity 0.15s ease, transform 0.15s cubic-bezier(0.2, 0, 0.13, 1.5), visibility 0s; }
    .nav-drawer-header { padding: 8px 16px; border-bottom: 1px solid rgba(255,255,255,0.06); display: flex; align-items: center; gap: 12px; }
    .nav-drawer-avatar { width: 42px; height: 42px; border-radius: 50%; background: linear-gradient(135deg, var(--accent-color), rgba(162,155,254,0.5)); display: flex; align-items: center; justify-content: center; font-size: 1.1rem; color: var(--accent-color); flex-shrink: 0; }
    .nav-drawer-info { min-width: 0; }
    .nav-drawer-title { font-size: 0.88rem; font-weight: 600; color: var(--text-primary); }
    .nav-drawer-subtitle { font-size: 0.7rem; color: var(--text-secondary); }
    .nav-drawer-items { padding: 6px 0; }
    .nav-drawer-item { display: flex; align-items: center; gap: 14px; padding: 0 16px; height: 44px; cursor: pointer; color: var(--text-primary); font-size: 0.85rem; transition: background 0.15s; }
    .nav-drawer-item:hover { background: rgba(255,255,255,0.08); }
    .nav-drawer-item svg { flex-shrink: 0; opacity: 0.55; width: 20px; height: 20px; }
    .nav-drawer-divider { height: 1px; background: rgba(255,255,255,0.06); margin: 4px 16px; }

    /* 移动端侧边栏抽屉 */
    @media (max-width: 768px) {
      .sidebar {
        position: fixed;
        top: 0;
        left: 0;
        bottom: 0;
        width: 280px;
        z-index: 200;
        transform: translateX(-100%);
        transition: transform 0.3s cubic-bezier(0.4, 0, 0.2, 1);
      }
    }