:root {
      --sidebar-width: 320px;
    }

    body {
      margin: 0;
      display: flex;
      height: 100vh;
      overflow: hidden;
      background-color: var(--bs-body-bg);
      color: var(--bs-body-color);
      transition: background 0.3s;
      font-family: 'Segoe UI', Roboto, sans-serif;
    }

    #sidebar {
      width: var(--sidebar-width);
      background: rgba(0, 0, 0, 0.25);
      border-right: 1px solid rgba(255, 255, 255, 0.1);
      display: flex;
      flex-direction: column;
      flex-shrink: 0;
    }

    .sidebar-header {
      padding: 1.5rem 1rem;
      border-bottom: 1px solid rgba(255, 255, 255, 0.1);
      text-align: center;
      cursor: pointer;
      transition: background 0.2s;
    }

    .sidebar-header:hover {
      background: rgba(255, 255, 255, 0.05);
    }

    .sidebar-header h3 {
      font-size: 1.3rem;
      font-weight: 800;
      margin-bottom: 0;
      text-transform: uppercase;
      letter-spacing: 1px;
    }

    .sidebar-header p {
      font-size: 0.8rem;
      margin-bottom: 0;
      opacity: 0.7;
    }

    .sidebar-content {
      flex-grow: 1;
      overflow-y: auto;
      padding: 10px;
      scrollbar-width: thin;
    }

    .nav-group-title {
      font-size: 0.7rem;
      text-transform: uppercase;
      letter-spacing: 1.5px;
      margin: 20px 0 8px 10px;
      opacity: 0.9;
      font-weight: bold;
      border-left: 3px solid currentColor;
      padding-left: 8px;
    }

    .nav-item-card {
      display: flex;
      align-items: flex-start;
      padding: 10px 12px;
      margin-bottom: 4px;
      border-radius: 6px;
      cursor: pointer;
      transition: all 0.15s;
      text-decoration: none;
      color: inherit;
      border: 1px solid transparent;
    }

    .nav-item-card:hover {
      background: rgba(255, 255, 255, 0.1);
      border-color: rgba(255, 255, 255, 0.1);
      transform: translateX(3px);
    }

    .icon-container {
      width: 24px;
      margin-right: 12px;
      margin-top: 2px;
      text-align: center;
    }

    .text-container {
      flex-grow: 1;
      display: flex;
      flex-direction: column;
      min-width: 0;
    }

    .nav-item-name {
      font-size: 0.85rem;
      font-weight: 600;
      white-space: nowrap;
      overflow: hidden;
      text-overflow: ellipsis;
    }

    .nav-item-desc {
      font-size: 0.72rem;
      opacity: 0.8;
      line-height: 1.2;
      margin-top: 2px;
    }

    /* Farb-Klassen für die Rubriken */
    .color-1 {
      color: #FFD700 !important;
    }

    /* Gold */
    .color-2 {
      color: #9cd33d !important;
    }

    /* MGM-Grün */
    .color-3 {
      color: #5bc0de !important;
    }

    /* Blau */
    .color-4 {
      color: #ff6eb4 !important;
    }

    /* Pink */

    .ext-icon {
      font-size: 0.6rem;
      margin-left: 5px;
      opacity: 0.6;
    }

    #main-content {
      flex-grow: 1;
      display: flex;
      flex-direction: column;
      background: #1c1f22;
      position: relative;
    }

    iframe {
      width: 100%;
      flex-grow: 1;
      border: none;
    }

    footer {
      padding: 10px 15px;
      font-size: 0.75rem;
      border-top: 1px solid rgba(255, 255, 255, 0.1);
      display: flex;
      justify-content: space-between;
      align-items: center;
    }

    #theme-selector {
      font-size: 0.75rem;
      padding: 3px 8px;
      background: rgba(0, 0, 0, 0.4);
      color: inherit;
      border: 1px solid rgba(255, 255, 255, 0.2);
      border-radius: 4px;
      outline: none;
    }