:root {
  --editor-font-size-xs: 16px;
  --editor-font-size-sm: 16px;
  --editor-font-size-md: 18px;
  --editor-font-size-lg: 18px;
  --editor-font-size-xl: 20px;
  --editor-max-width: 40em;
  --editor-padding-pane: 1rem;
  --editor-transition: 250ms ease-in-out;
  --editor-transition-fast: 150ms ease-out;
  --sidebar-width: 320px;
  --preview-width: 1fr;
  --editor-font-size: var(--editor-font-size-xs);
  --editor-border-color: var(--surface-4);
  --editor-header-height: 60px;
  --editor-radius: 8px;
  --editor-shadow: 0 2px 8px rgba(0, 0, 0, 0.1);
  --editor-shadow-hover: 0 4px 12px rgba(0, 0, 0, 0.15);

  @media (prefers-color-scheme:dark) {
    --editor-border-color: var(--surface-1);
    --editor-shadow: 0 2px 8px rgba(0, 0, 0, 0.3);
    --editor-shadow-hover: 0 4px 12px rgba(0, 0, 0, 0.4);
  }

}

body.layout-editor {
  display: grid;
  grid-template-columns: 0fr 1fr 0fr;
  grid-template-areas:
    "header header header"
    "sidebar main preview"
    "footer footer footer";
  grid-template-rows: auto 1fr auto;/*  transition: grid-template-columns var(--editor-transition);*/
  margin: 0;
  height: 100dvh;
  overflow-x: hidden;
  color: var(--text-1);

  #sidebar {
    display: flex;
    visibility: hidden;
    width: 0;
    overflow: hidden;
  }

  /* State 1: Sidebar is open, Preview is closed */
  &.sidebar-open:not(.preview-open) {
    grid-template-columns: var(--sidebar-width) 1fr 0fr;

    #sidebar {
      visibility: visible;
      width: var(--sidebar-width);
    }

  }

  /* State 2: Preview is open, Sidebar is closed */
  &.preview-open:not(.sidebar-open) {
    /* Editor + Preview */
    grid-template-columns: 0fr 1fr var(--preview-width);
  }

  /* State 3: Both Sidebar and Preview are open */
  &.sidebar-open.preview-open {

    /* Sidebar + Editor + Preview */
    grid-template-columns: var(--sidebar-width) 1fr var(--preview-width);

    #sidebar {
      visibility: visible;
      width: var(--sidebar-width);
    }
  }

  :where(#header) {
    grid-area: header;
    display: grid;
    grid-template-columns: auto auto 1fr;
    grid-template-areas: "navigation title actions";
    grid-template-rows: auto;
    align-items: center;
    font-size: var(--font-size-sm);
    font-weight: 500;
    gap: var(--space-md);
    height: var(--editor-header-height);
    background: var(--surface-1);
    backdrop-filter: blur(10px);
    -webkit-backdrop-filter: blur(10px);
    box-shadow: 0 1px 0 var(--editor-border-color);
    padding: 0 var(--space-lg);
    position: relative;
    z-index: 100;

    @media (min-width:60em) {
      grid-template-columns: 1fr 1fr 1fr;
    }

    .navigation {
      grid-area: navigation;
      display: flex;
      justify-content: flex-start;
      align-items: center;
    }

    .title {
      grid-area: title;
      display: flex;
      justify-content: center;
      align-items: center;
      gap: var(--space-md);
      font-weight: 600;
      color: var(--text-1);
    }

    .actions {
      grid-area: actions;
      display: flex;
      justify-content: flex-end;
      align-items: center;
      gap: var(--space-sm);
    }

    .editor-toggles {
      display: flex;
      gap: var(--space-xs);
      
      .btn, label {
        &.active {
          background: var(--surface-4);
        }
      }
    }

  }

  :where(#sidebar) {
    grid-area: sidebar;
    font-size: 14px;
    background: var(--surface-3);
    border-right: 1px solid var(--editor-border-color);
    flex-direction: column;
    overflow: hidden;

    /* Tab Navigation */
    .sidebar-tabs {
      display: flex;
      gap: var(--space-xs);
      padding: var(--space-md);
      border-bottom: 1px solid var(--editor-border-color);
      background: var(--surface-2);
    }

    .sidebar-tab {
      flex: 1;
      padding: var(--space-sm);
      background: transparent;
      border: 1px solid transparent;
      border-radius: var(--radius-1);
      cursor: pointer;
      transition: background-color var(--editor-transition-fast), border-color var(--editor-transition-fast);
      display: flex;
      align-items: center;
      justify-content: center;

      img {
        opacity: 0.6;
        transition: opacity var(--editor-transition-fast);
        
        @media (prefers-color-scheme: dark) {
          filter: invert(1);
        }
      }

      &:hover {
        background: var(--surface-3);
        
        img {
          opacity: 0.8;
        }
      }

      &:focus-visible {
        outline: 2px solid var(--brand);
        outline-offset: -2px;
      }

      &.active {
        background: var(--surface-4);
        border-color: var(--surface-4);

        img {
          opacity: 1;
        }
      }
    }

    /* Tab Panels */
    .sidebar-panels {
      flex: 1;
      overflow-y: auto;
      overflow-x: hidden;
    }

    .sidebar-panel {
      padding: var(--space-lg);
      display: none;

      &[aria-hidden="false"] {
        display: block;
      }
    }

    .panel-title {
      font-size: 0.875rem;
      font-weight: 600;
      text-transform: uppercase;
      letter-spacing: 0.05em;
      color: var(--text-2);
      margin-bottom: var(--space-md);
    }


    .btn--naked {
      width: 100%;
      text-align: left;
      align-items: center;
      justify-content: flex-start;
      gap: var(--space-md);
      overflow: hidden;
      text-overflow: ellipsis;
    }

  }

  :where(#main) {
    grid-area: main;
    overflow-y: auto;
    width: 100%;
    height: 100%;
    transition: font-size var(--editor-transition);
    font-size: var(--editor-font-size);


    #markdown-form {
      height: 100%;

      .editor {
        height: 100%;
        line-height: 1.5rem;
        
        /* Ace editor customizations */
        .ace_editor {
          font-family: var(--font-mono) !important;
          
          &.ace_focus {
            box-shadow: inset 0 0 0 2px var(--brand);
            border-radius: var(--radius-2);
          }
          
          .ace_placeholder {
            color: var(--text-3);
            font-style: italic;
            opacity: 0.5;
          }
          
          .ace_cursor {
            border-color: var(--brand);
            animation: blink 1s infinite;
          }
        }
      }
      
      @keyframes blink {
        0%, 50% { opacity: 1; }
        51%, 100% { opacity: 0; }
      }

      /* Drag and drop state */
      .editor--dragover {
        position: relative;
        
        &::after {
          content: '';
          position: absolute;
          inset: 0;
          background-color: var(--app-primary);
          opacity: 0.1;
          border: 2px dashed var(--app-primary);
          pointer-events: none;
          z-index: 10;
          border-radius: var(--radius-2);
        }
      }

    }

  }

  :where(#preview) {
    grid-area: preview;
    padding: 0;
    overflow: hidden;
    width: 100%;
    resize: inline;
    border-left: 8px solid var(--editor-border-color);
  }

  /* Save Indicator - Minimal Asterisk in Title */
  .save-indicator {
    display: inline-block;
    width: 3ch;
    text-align: center;
    transition: opacity var(--editor-transition-fast);
    
    /* Saved state - nothing shown */
    &[data-saved="true"]::after {
      content: "[S]";
    }
    
    /* Unsaved state - show asterisk */
    &[data-saved="false"]::after {
      content: "[*]";
    }
  }

  /* Uploads in sidebar */
  #tray img {
    cursor: pointer;
    transition: all var(--editor-transition);
    max-width: 100%;
  }

  #tray img:hover {
    opacity: 0.8;
  }

  /* Section list styling */
  .section-list {
    list-style: none;
    padding: 0;
    margin: 0;
    display: flex;
    flex-direction: column;
    gap: var(--space-xs);

    .section-item {
      padding: var(--space-md);
      border-radius: var(--radius-2);
      background: var(--surface-1);
      cursor: pointer;
      transition: background-color var(--editor-transition-fast);
      position: relative;
      overflow: hidden;
      border: 1px solid var(--surface-1);

      &:hover {
        background: var(--surface-2);
        border-color: var(--surface-2);

        .section-name {
          color: var(--brand);
        }
      }

      &:active {
        background: var(--surface-3);
        border-color: var(--surface-3);
      }
    }

    .section-name {
      font-weight: 600;
      margin-bottom: 2px;
      transition: color var(--editor-transition-fast);
    }

    .section-description {
      font-size: 0.8rem;
      color: var(--text-2);
      overflow: hidden;
      text-overflow: ellipsis;
      display: -webkit-box;
      -webkit-line-clamp: 2;
      -webkit-box-orient: vertical;
      line-height: 1.4;
    }

  }

  /* Markdown Actions styling */
  .markdown-actions {
    display: flex;
    flex-direction: column;
    gap: var(--space-xs);

    .btn--naked {
      justify-content: flex-start;
      text-align: left;
      padding: var(--space-md);
      border-radius: var(--radius-2);
      background: var(--surface-1);
      border: 1px solid var(--surface-1);
      transition: background-color var(--editor-transition-fast), border-color var(--editor-transition-fast);

      img {
        @media (prefers-color-scheme: dark) {
          filter: invert(1);
        }
      }

      &:hover {
        background: var(--surface-2);
        border-color: var(--surface-2);

        .action-label > span:first-child {
          color: var(--brand);
        }
      }

      &:active {
        background: var(--surface-3);
        border-color: var(--surface-3);
      }

      .action-label {
        display: flex;
        flex-direction: column;
        align-items: flex-start;
        gap: 2px;
        flex: 1;
      }

      .action-hint {
        font-size: 0.8rem;
        color: var(--text-2);
        font-family: var(--font-mono);
      }
    }

    .btn--upload {
      border-style: dashed;
      border-color: var(--surface-3);

      &:hover {
        border-style: dashed;
        border-color: var(--surface-4);
        background: var(--surface-2);
      }
    }
  }

  /* Upload tray styling */
  #tray {
    .file-input {
      position: absolute;
      width: 0.1px;
      height: 0.1px;
      opacity: 0;
      overflow: hidden;
      z-index: -1;
    }

    form {
      margin: 0;
    }

    .upload-label {
      display: flex;
      align-items: center;
      gap: var(--space-sm);
      width: 100%;
      padding: var(--space-md);
      border-radius: var(--radius-2);
      background: var(--surface-1);
      border: 1px dashed var(--surface-3);
      cursor: pointer;
      font-size: 0.875rem;
      font-weight: 600;
      justify-content: center;
      transition: background-color var(--editor-transition-fast), border-color var(--editor-transition-fast);
      margin-bottom: var(--space-md);
      box-sizing: border-box;

      &:hover {
        background: var(--surface-2);
        border-color: var(--surface-4);
        
        span {
          color: var(--brand);
        }
      }
    }

    .upload-grid {
      display: grid;
      grid-template-columns: repeat(auto-fill, minmax(60px, 1fr));
      gap: var(--space-xs);

      .upload-item {
        position: relative;
        aspect-ratio: 1;
        
        img {
          width: 100%;
          height: 100%;
          object-fit: cover;
          border-radius: var(--radius-1);
          cursor: pointer;
          transition: opacity var(--editor-transition-fast);

          &:hover {
            opacity: 0.8;
          }
        }

        .upload-actions {
          position: absolute;
          top: 2px;
          right: 2px;
          display: none;
          
          .btn--delete {
            background: rgba(0, 0, 0, 0.7);
            border: none;
            padding: 4px;
            border-radius: var(--radius-1);
            cursor: pointer;
            display: flex;
            align-items: center;
            justify-content: center;

            img {
              width: 12px;
              height: 12px;
              filter: invert(1);
            }

            &:hover {
              background: rgba(0, 0, 0, 0.9);
            }
          }
          
          .delete-form {
            margin: 0;
          }
        }

        &:hover .upload-actions {
          display: block;
        }
      }
    }

    .empty-state {
      text-align: center;
      padding: var(--space-lg);
      color: var(--text-3);
      font-size: 0.875rem;
    }
  }

  /* Settings Panel */
  .settings-content {
    display: flex;
    flex-direction: column;
    gap: var(--space-lg);
  }

  .setting-group {
    display: flex;
    flex-direction: column;
    gap: var(--space-sm);
  }

  .setting-label {
    font-weight: 600;
    font-size: 0.875rem;
    color: var(--text-1);
  }

  .setting-select {
    padding: var(--space-sm) var(--space-md);
    background: var(--surface-1);
    border: 1px solid var(--surface-4);
    border-radius: var(--radius-1);
    color: var(--text-1);
    font-size: 0.875rem;
    cursor: pointer;

    &:disabled {
      opacity: 0.5;
      cursor: not-allowed;
    }
  }

  .setting-hint {
    font-size: 0.75rem;
    color: var(--text-3);
    margin: 0;
  }

  .setting-options {
    display: flex;
    align-items: center;
    gap: var(--space-md);

    .btn img {
      @media (prefers-color-scheme: dark) {
        filter: invert(1);
      }
    }
  }

  .setting-value {
    font-family: var(--font-mono);
    font-size: 0.875rem;
    color: var(--text-2);
  }

  .setting-info {
    background: var(--surface-1);
    padding: var(--space-md);
    border-radius: var(--radius-2);
    font-size: 0.875rem;

    p {
      margin: 0 0 var(--space-xs) 0;
      
      &:last-child {
        margin-bottom: 0;
      }
    }

    strong {
      color: var(--text-2);
    }
  }

  .setting-actions {
    display: flex;
    flex-direction: column;
    gap: var(--space-sm);
    
    .btn {
      justify-content: flex-start;
      width: 100%;
      
      img {
        @media (prefers-color-scheme: dark) {
          filter: invert(1);
        }
      }
    }
  }

}