@layer components {
  .schema-header {
    padding: 0;
    font-weight: 600;
    font-size: var(--size-fluid-1);
    text-transform: uppercase;
    letter-spacing: 0.05em;
    color: var(--color-text-muted);
    border-bottom: 1px solid var(--color-border-light);
    display: flex;
    align-items: center;
    justify-content: space-between;
  }

  .panel-section-header {
    display: flex;
    align-items: center;
    justify-content: space-between;
    padding: var(--space-2) var(--space-3);
    font-size: var(--size-fluid-1);
    font-weight: 600;
    text-transform: uppercase;
    letter-spacing: 0.05em;
    color: var(--color-text-muted);
    border-bottom: 1px solid var(--color-border-light);
    flex-shrink: 0;
  }

  .section-node {
    display: flex;
    flex-direction: column;
    min-height: 0;
    flex: 1;
    overflow: hidden;
  }

  .section-node-fixed {
    flex: 0 0 auto;
    border-top: 1px solid var(--color-border);
  }


  .section-header {
    display: flex;
    align-items: center;
    gap: var(--space-1);
    padding: 3px var(--space-2);
    font-size: 11px;
    font-weight: 600;
    text-transform: uppercase;
    letter-spacing: 0.05em;
    color: var(--color-text-muted);
    border-top: 1px solid var(--color-border-light);
    border-bottom: 1px solid var(--color-border-light);
    cursor: pointer;
    user-select: none;
    flex-shrink: 0;
  }

  .section-header:hover {
    color: var(--color-text);
  }

  .section-arrow {
    font-size: 10px;
    width: 16px;
    text-align: center;
    flex-shrink: 0;
  }

  .section-label {
    flex: 1;
  }

  .section-add-btn {
    font-size: 14px;
    line-height: 1;
    padding: 0 6px;
    height: 22px;
    border-radius: var(--radius-sm);
    border: 1px solid var(--color-border);
    background: var(--color-bg-hover);
    color: var(--color-text-muted);
    cursor: pointer;
  }

  .section-add-btn:hover {
    background: var(--color-accent);
    color: var(--color-accent-text);
    border-color: var(--color-accent);
  }

  .section-body {
    overflow: hidden;
    min-height: 0;
    flex: 1;
  }

  .section-body.collapsed {
    display: none;
    flex: 0 0 0 !important;
  }

  .ops-bar {
    display: flex;
    flex-wrap: wrap;
    gap: var(--space-1);
    padding: var(--space-1) var(--space-2);
    border-bottom: 1px solid var(--color-border-light);
  }

  .ops-bar .btn {
    font-size: 14px;
    padding: 3px 8px;
  }
 

  .ops-footer {
    display: flex;
    align-items: center;
    justify-content: space-between;
    padding: var(--space-2) var(--space-3);
    border-top: 1px solid var(--color-border-light);
    font-size: 10px;
  }

  .ops-logo {
    font-weight: 700;
    color: var(--color-accent);
    cursor: pointer;
    display: flex;
    align-items: center;
    line-height: 1;
    text-decoration: underline;
    text-decoration-color: #3b82f6;
  }

  .ops-logo img {
    height: 22px;
    width: auto;
    display: block;
    border-radius: 3px;
  }

  [data-theme="dark"] .ops-logo img {
    filter: brightness(1.4) contrast(0.9);
  }

  .ops-logo:hover {
    text-decoration: underline;
  }

  .ops-link {
    color: var(--color-text-muted);
    text-decoration: none;
  }

  .ops-link:hover {
    color: var(--color-accent);
  }

  .files-tree {
    padding: var(--space-1) 0;
    overflow-y: auto;
    flex: 1;
    min-height: 60px;
  }

  #section-files {
    flex: 1;
    display: flex;
    flex-direction: column;
    overflow: hidden;
    min-height: 0;
  }

  #section-schema {
    flex: 1;
    display: flex;
    flex-direction: column;
    overflow: hidden;
    min-height: 0;
  }

  #section-tutorial {
    flex: 1;
    display: flex;
    flex-direction: column;
    overflow: hidden;
    min-height: 0;
  }

  .tutorial-panel {
    display: flex;
    flex-direction: column;
    gap: var(--space-1);
    padding: var(--space-2) var(--space-3);
    min-height: 0;
    height: 100%;
  }

  .tutorial-toolbar {
    display: flex;
    gap: var(--space-1);
    align-items: center;
  }

  .tutorial-xp-bar {
    display: flex;
    align-items: center;
    gap: var(--space-2);
    font-size: 10px;
    padding: 2px 0;
  }

  .tutorial-font-slider-wrap {
    margin-left: auto;
    display: flex;
    align-items: center;
    gap: 4px;
    flex-shrink: 0;
  }

  .tutorial-font-label {
    font-size: 9px;
    font-weight: 700;
    color: var(--color-text-muted);
    line-height: 1;
  }

  .tutorial-font-label:last-child {
    font-size: 12px;
  }

  .tutorial-font-slider {
    width: 48px;
    height: 4px;
    -webkit-appearance: none;
    appearance: none;
    background: var(--color-border-light);
    border-radius: 2px;
    cursor: pointer;
    margin: 0;
    padding: 0;
    vertical-align: middle;
  }

  .tutorial-font-slider::-webkit-slider-thumb {
    -webkit-appearance: none;
    width: 12px;
    height: 12px;
    border-radius: 50%;
    background: var(--color-accent);
    border: none;
    cursor: pointer;
  }

  .tutorial-font-slider::-moz-range-thumb {
    width: 12px;
    height: 12px;
    border-radius: 50%;
    background: var(--color-accent);
    border: none;
    cursor: pointer;
  }

  .btn-tutorial-fs {
    background: none;
    border: none;
    color: var(--color-text-muted);
    cursor: pointer;
    font-size: 18px;
    line-height: 1;
    padding: 2px 6px;
    border-radius: 3px;
    display: flex;
    align-items: center;
    transition: background 0.15s;
  }

  .btn-tutorial-fs:hover {
    background: color-mix(in srgb, var(--color-text-muted) 15%, transparent);
  }

  /* Tutorial fullscreen mode */
  .tutorial-fullscreen #section-tutorial {
    position: fixed;
    inset: 0;
    z-index: 9999;
    background: var(--color-bg);
    padding: var(--space-4);
  }

  .tutorial-fullscreen .tutorial-panel {
    max-width: 800px;
    margin: 0 auto;
    height: 100%;
  }

  .tutorial-fullscreen .tutorial-content {
    font-size: calc(var(--tutorial-font-size, 13px) + 4px);
  }

  .tutorial-xp-text {
    color: #f59e0b;
    font-weight: 700;
    letter-spacing: 0.03em;
  }

  .tutorial-streak-text {
    color: var(--color-error);
    font-weight: 600;
    font-size: 10px;
  }

  .tutorial-progress {
    display: flex;
    align-items: center;
    gap: var(--space-1);
    font-size: 11px;
    color: var(--color-text-muted);
    text-transform: uppercase;
    letter-spacing: 0.04em;
    min-width: 0;
  }

  .tutorial-module-select {
    font-size: 11px;
    font-family: var(--font-ui);
    background: var(--color-bg);
    color: var(--color-text);
    border: 1px solid var(--color-border);
    border-radius: var(--radius-sm);
    padding: 1px 4px;
    max-width: 110px;
    flex-shrink: 0;
    text-transform: uppercase;
    letter-spacing: 0.04em;
    overflow: hidden;
    text-overflow: ellipsis;
    white-space: nowrap;
  }

  #tutorial-lesson-progress {
    overflow: hidden;
    text-overflow: ellipsis;
    white-space: nowrap;
  }

  .tutorial-progress-bar {
    display: flex;
    align-items: center;
    gap: var(--space-1);
    height: 4px;
    background: var(--color-border-light);
    border-radius: 2px;
    overflow: hidden;
  }

  .tutorial-progress-fill {
    height: 100%;
    background: var(--color-accent);
    border-radius: 2px;
    transition: width 0.3s;
  }

  .tutorial-progress-label {
    font-size: 9px;
    color: var(--color-text-muted);
    white-space: nowrap;
  }

  .tutorial-status {
    font-size: 11px;
    color: var(--color-text-muted);
    min-height: 16px;
  }

  .tutorial-status.is-success {
    color: var(--color-accent);
  }

  .tutorial-status.is-error {
    color: var(--color-error);
  }

  .tutorial-content {
    flex: 1;
    min-height: 80px;
    overflow-y: auto;
    font-size: var(--tutorial-font-size, 13px);
    line-height: 1.55;
    padding-right: 4px;
  }

  .tutorial-content h1,
  .tutorial-content h2,
  .tutorial-content h3 {
    margin: 0 0 var(--space-2);
    line-height: 1.2;
  }

  .tutorial-content p,
  .tutorial-content ul {
    margin: 0 0 var(--space-2);
  }

  .tutorial-content pre {
    margin: var(--space-2) 0;
    padding: var(--space-2);
    background: var(--color-bg);
    border: 1px solid var(--color-border-light);
    border-radius: var(--radius-sm);
    overflow-x: auto;
    white-space: pre-wrap;
  }

  .tutorial-content code {
    font-family: var(--font-mono);
    font-size: var(--tutorial-code-font-size, var(--tutorial-font-size, 13px));
    background: color-mix(in srgb, #f59e0b 15%, var(--color-bg));
    padding: 1px 4px;
    border-radius: 3px;
  }

  .tutorial-content pre {
    margin: var(--space-2) 0;
    padding: var(--space-2);
    background: color-mix(in srgb, #f59e0b 8%, var(--color-bg));
    border: 1px solid color-mix(in srgb, #f59e0b 20%, var(--color-border-light));
    border-radius: var(--radius-sm);
    overflow-x: auto;
    white-space: pre-wrap;
    font-size: var(--tutorial-code-font-size, var(--tutorial-font-size, 13px));
  }

  .tutorial-content pre code {
    font-size: var(--tutorial-code-font-size, var(--tutorial-font-size, 13px));
    background: none;
  }

  .tutorial-content table {
    width: 100%;
    border-collapse: collapse;
    margin: var(--space-2) 0;
    font-size: var(--tutorial-table-font-size, 11px);
  }

  .tutorial-content th,
  .tutorial-content td {
    padding: 4px 8px;
    border: 1px solid var(--color-border-light);
    text-align: left;
    font-size: var(--tutorial-table-font-size, 11px);
  }

  .tutorial-content th {
    background: var(--color-bg);
    font-weight: 600;
  }

  .tutorial-files {
    font-size: 11px;
    color: var(--color-text-muted);
    border-top: 1px solid var(--color-border-light);
    padding-top: var(--space-2);
  }

  .schema-tree {
    padding: var(--space-1) 0;
    flex: 1;
    overflow-y: auto;
    min-height: 60px;
  }

  .sidebar-resize-handle {
    height: 4px;
    cursor: row-resize;
    background: transparent;
    transition: background 0.15s;
    flex-shrink: 0;
  }

  .sidebar-resize-handle:hover,
  .sidebar-resize-handle:active {
    background: var(--color-accent);
  }

  .file-tree-item {
    display: flex;
    align-items: center;
    gap: 2px;
    padding: 1px var(--space-2);
    cursor: pointer;
    font-size: 12px;
    font-family: var(--font-mono);
    color: var(--color-text);
    border: none;
    background: none;
    text-align: left;
    width: 100%;
    line-height: 1.6;
    content-visibility: auto;
    contain-intrinsic-size: 25px;
  }

  .file-tree-item.drag-over {
    outline: 2px dashed var(--color-accent);
    outline-offset: -2px;
    background: color-mix(in srgb, var(--color-accent) 15%, transparent);
  }
  .file-tree-item:hover {
    background: var(--color-bg-hover);
  }

  .file-tree-item.active {
    background: var(--color-bg-active);
    color: var(--color-accent);
  }

  .file-tree-item.selected {
    outline: 1px dashed var(--color-accent);
    outline-offset: -1px;
  }

  .file-tree-item .file-icon {
    flex-shrink: 0;
    font-size: 12px;
    width: 16px;
    text-align: center;
  }

  .file-tree-item .file-name {
    flex: 1;
    overflow: hidden;
    text-overflow: ellipsis;
    white-space: nowrap;
  }

  .file-tree-item .file-del {
    font-size: 12px;
    color: var(--color-text-muted);
    padding: 2px 6px;
    border-radius: var(--radius-sm);
    border: none;
    background: none;
    cursor: pointer;
    opacity: 0;
  }

  .file-tree-item:hover .file-del {
    opacity: 1;
  }

  .file-tree-item .file-del:hover {
    color: var(--color-error);
    background: color-mix(in srgb, var(--color-error) 15%, transparent);
  }

  .folder-toggle {
    flex-shrink: 0;
    width: 24px;
    text-align: center;
    font-size: 16px;
    color: var(--color-text-muted);
    cursor: pointer;
    user-select: none;
  }

  .folder-toggle:hover {
    color: var(--color-accent);
  }

  .folder-children {
    overflow: hidden;
  }

  .schema-header-title {
    color: var(--color-accent);
  }

  .schema-header-file {
    display: none;
    color: var(--color-text-muted);
  }

  .schema-toolbar {
    display: none;
    flex-wrap: wrap;
    gap: var(--space-1);
    padding: var(--space-2) var(--space-3);
    border-bottom: 1px solid var(--color-border-light);
  }

  .schema-toolbar-btn {
    font-size: var(--size-fluid-1);
  }

  @media (max-width: 768px) {
    .schema-toolbar {
      display: flex;
    }
  }

  .schema-tree {
    padding: var(--space-1) 0;
    flex: 1;
    overflow-y: auto;
  }
  

 

  .schema-empty {
    padding: var(--space-4) var(--space-3);
    color: var(--color-text-muted);
    font-size: var(--size-fluid-1);
    font-style: italic;
  }

  .schema-table {
    user-select: none;
  }

  .schema-section-label {
    font-size: 10px;
    font-weight: 600;
    text-transform: uppercase;
    letter-spacing: 0.06em;
    color: var(--color-text-muted);
    padding: var(--space-2) var(--space-2) 2px;
    margin-top: var(--space-1);
  }

  .schema-table-name {
    display: flex;
    align-items: center;
    gap: var(--space-1);
    padding: 1px var(--space-2);
    cursor: pointer;
    font-size: var(--size-fluid-2);
    font-weight: 500;
    border-left: 3px solid transparent;
  }

  .schema-table-name:hover {
    background: var(--color-bg-hover);
  }

  .schema-table-name.active {
    background: var(--color-bg-active);
    border-left-color: var(--color-accent);
  }

  .schema-table-name.active .schema-table-label {
    color: var(--color-accent);
  }

  .schema-table-actions {
    margin-left: auto;
    display: flex;
    gap: 2px;
    opacity: 0;
    transition: opacity 0.1s;
  }

  .schema-table-name:hover .schema-table-actions {
    opacity: 1;
  }

  .btn-schema-ddl,
  .btn-schema-drop {
    font-family: var(--font-mono);
    font-size: var(--size-fluid-0);
    padding: 0 5px;
    border-radius: var(--radius-sm);
    border: 1px solid var(--color-border);
    background: var(--color-bg-hover);
    color: var(--color-text-muted);
    cursor: pointer;
    line-height: 1.4;
  }

  .btn-schema-ddl:hover {
    background: var(--color-accent);
    color: var(--color-accent-text);
    border-color: var(--color-accent);
  }

  .btn-schema-drop:hover {
    background: var(--color-error);
    color: var(--color-text-inverse);
    border-color: var(--color-error);
  }

  @media (max-width: 768px) {
    .btn-schema-ddl,
    .btn-schema-drop {
      font-size: 14px;
      padding: 4px 10px;
    }
    .schema-table-actions {
      opacity: 1;
    }
  }

  .schema-table-name .expand-icon {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    width: 32px;
    height: 32px;
    min-width: 32px;
    font-size: 16px;
    color: var(--color-text-muted);
    border-radius: var(--radius-sm);
    user-select: none;
    -webkit-tap-highlight-color: transparent;
    cursor: pointer;
  }

  .schema-table-name .expand-icon:hover {
    background: var(--color-bg-active);
  }

  @media (max-width: 768px) {
    .schema-table-name .expand-icon {
      width: 40px;
      height: 40px;
      min-width: 40px;
      font-size: 20px;
    }
  }

  .schema-columns {
    overflow: hidden;
  }

  .schema-column {
    display: flex;
    align-items: center;
    gap: var(--space-1);
    padding: 1px var(--space-3) 1px var(--space-6);
    font-size: var(--size-fluid-1);
    color: var(--color-text-muted);
  }

  .schema-column:hover {
    background: var(--color-bg-hover);
  }

  .schema-column .col-type {
    font-size: 10px;
    color: var(--color-accent);
    opacity: 0.7;
    margin-left: auto;
  }

  .col-badge {
    font-size: 9px;
    font-weight: 700;
    padding: 0 4px;
    border-radius: 2px;
    line-height: 1.4;
    margin-left: 2px;
  }

  .col-pk { color: #eab308; }
  .col-fk { color: #a855f7; }
  .col-uq { color: #22c55e; }
  .col-ai { color: #f97316; }
  .col-nn { color: #ef4444; }
  .col-idx { color: #06b6d4; }

  .schema-indexes {
    padding: var(--space-1) var(--space-4) var(--space-1);
    border-top: 1px solid var(--color-border-light);
    margin-top: var(--space-1);
  }
  .schema-index {
    display: flex;
    align-items: center;
    gap: var(--space-2);
    padding: 2px 0;
    font-size: var(--size-fluid-1);
  }
  .schema-index .col-type {
    color: var(--color-text-muted);
    font-family: var(--font-mono);
    font-size: var(--size-fluid-1);
  }

  .context-menu {
    position: fixed;
    z-index: 1000;
    min-width: 200px;
    background: var(--color-bg-surface);
    border: 1px solid var(--color-border);
    border-radius: var(--radius-md);
    box-shadow: 0 4px 16px rgba(0,0,0,0.2);
    padding: var(--space-1) 0;
  }

  .context-menu-item {
    display: block;
    width: 100%;
    text-align: left;
    padding: var(--space-1) var(--space-3);
    font-size: var(--size-fluid-1);
    border: none;
    background: none;
    cursor: pointer;
    color: var(--color-text);
  }

  .context-menu-item:hover {
    background: var(--color-accent);
    color: var(--color-accent-text);
  }

  .context-menu-item.danger:hover {
    background: var(--color-error);
    color: #fff;
  }

  /* ── Toast Notifications ── */
  .toast-container {
    position: fixed;
    top: 12px;
    right: 12px;
    z-index: 10000;
    display: flex;
    flex-direction: column;
    gap: 8px;
    pointer-events: none;
    max-width: 360px;
  }

  .toast {
    display: flex;
    align-items: center;
    gap: 8px;
    padding: 10px 14px;
    border-radius: 8px;
    font-size: 13px;
    font-weight: 500;
    line-height: 1.3;
    background: var(--color-bg-surface);
    border: 1px solid var(--color-border);
    box-shadow: 0 4px 16px rgba(0,0,0,0.18);
    pointer-events: auto;
    transform: translateX(120%);
    transition: transform 0.35s cubic-bezier(0.16, 1, 0.3, 1), opacity 0.35s;
    opacity: 0;
  }

  .toast-visible {
    transform: translateX(0);
    opacity: 1;
  }

  .toast-icon {
    font-size: 18px;
    flex-shrink: 0;
  }

  .toast-msg {
    flex: 1;
    color: var(--color-text);
  }

  .toast-success { border-left: 4px solid #22c55e; }
  .toast-error { border-left: 4px solid #ef4444; }
  .toast-info { border-left: 4px solid #3b82f6; }
  .toast-xp { border-left: 4px solid #f59e0b; }
  .toast-warning { border-left: 4px solid #f97316; }
  .toast-celebration { border-left: 4px solid #a855f7; }

  /* ── Checklist Styles ── */
  .tutorial-checklist {
    margin: var(--space-2) 0;
    padding: 0;
    list-style: none;
  }

  .tutorial-checklist-item {
    display: flex;
    align-items: flex-start;
    gap: 8px;
    padding: 4px 0;
    font-size: 12px;
    line-height: 1.4;
    color: var(--color-text-muted);
    transition: color 0.3s;
  }

  .tutorial-checklist-item.is-done {
    color: var(--color-accent);
    text-decoration: none;
  }

  .tutorial-checklist-item .check-box {
    flex-shrink: 0;
    width: 16px;
    height: 16px;
    border: 1.5px solid var(--color-border);
    border-radius: 3px;
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 10px;
    margin-top: 1px;
    transition: all 0.25s;
  }

  .tutorial-checklist-item.is-done .check-box {
    background: var(--color-accent);
    border-color: var(--color-accent);
    color: var(--color-accent-text);
  }

  .tutorial-checklist-counter {
    font-size: 10px;
    color: var(--color-text-muted);
    margin: var(--space-1) 0;
  }

  /* ── Solution View ── */
  .solution-banner {
    display: flex;
    align-items: center;
    gap: 8px;
    padding: 8px 12px;
    background: color-mix(in srgb, #f59e0b 12%, var(--color-bg));
    border: 1px solid color-mix(in srgb, #f59e0b 30%, var(--color-border));
    border-radius: 6px;
    font-size: 11px;
    color: #f59e0b;
    margin-bottom: var(--space-2);
  }

  .cm-editor.cm-readonly .cm-content {
    opacity: 0.7;
  }
  #editor-container-1 .cm-editor.cm-readonly .cm-scroller {
    align-items: center;
  }

  /* ── XP Float Animation ── */
  .xp-float {
    position: fixed;
    pointer-events: none;
    font-size: 20px;
    font-weight: 800;
    color: #f59e0b;
    z-index: 10001;
    animation: xpFloatUp 1.2s ease-out forwards;
  }

  @keyframes xpFloatUp {
    0% { opacity: 1; transform: translateY(0) scale(1); }
    60% { opacity: 1; transform: translateY(-40px) scale(1.2); }
    100% { opacity: 0; transform: translateY(-80px) scale(0.8); }
  }

  .tutorial-status.has-checklist {
    margin-bottom: 4px;
  }

  /* ── Challenge Section ── */

  #section-challenges {
    flex: 1;
    display: flex;
    flex-direction: column;
    overflow: hidden;
    min-height: 0;
  }

  .challenge-list {
    padding: var(--space-1) 0;
    overflow-y: auto;
    flex: 1;
    min-height: 60px;
  }

  .ch-item {
    display: flex;
    flex-direction: column;
    gap: 2px;
    padding: 6px var(--space-2);
    cursor: pointer;
    border-bottom: 1px solid var(--color-border-light);
  }

  .ch-item:hover {
    background: var(--color-bg-hover);
  }

  .ch-item-title {
    display: flex;
    align-items: center;
    gap: 4px;
    font-size: 12px;
  }

  .ch-item-icon {
    flex-shrink: 0;
  }

  .ch-item-name {
    flex: 1;
    overflow: hidden;
    text-overflow: ellipsis;
    white-space: nowrap;
    font-weight: 500;
  }

  .ch-item-progress {
    font-size: 10px;
    color: var(--color-text-muted);
  }

  .ch-item-bar {
    height: 3px;
    background: var(--color-border-light);
    border-radius: 2px;
    overflow: hidden;
  }

  .ch-item-fill {
    height: 100%;
    background: var(--color-accent);
    border-radius: 2px;
    transition: width 0.3s;
  }

  .ch-badge {
    font-size: 9px;
    font-weight: 700;
    padding: 1px 5px;
    border-radius: 3px;
    text-transform: uppercase;
    letter-spacing: 0.03em;
    flex-shrink: 0;
  }

  .ch-badge-easy {
    background: color-mix(in srgb, #22c55e 20%, transparent);
    color: #22c55e;
  }

  .ch-badge-medium {
    background: color-mix(in srgb, #f59e0b 20%, transparent);
    color: #f59e0b;
  }

  .ch-badge-hard {
    background: color-mix(in srgb, #ef4444 20%, transparent);
    color: #ef4444;
  }

  .ch-tag {
    display: inline-block;
    font-size: 9px;
    padding: 1px 5px;
    border-radius: 3px;
    background: var(--color-bg);
    border: 1px solid var(--color-border-light);
    color: var(--color-text-muted);
    margin: 1px;
  }

  /* ── Challenge Detail ── */

  .ch-detail {
    display: flex;
    flex-direction: column;
    gap: var(--space-1);
    padding: var(--space-2);
  }

  .ch-detail-header {
    display: flex;
    align-items: center;
    gap: var(--space-1);
  }

  .ch-detail-title {
    font-weight: 600;
    font-size: 13px;
    flex: 1;
    overflow: hidden;
    text-overflow: ellipsis;
    white-space: nowrap;
  }

  .ch-detail-tags {
    display: flex;
    flex-wrap: wrap;
    gap: 2px;
  }

  .ch-detail-progress {
    font-size: 10px;
    color: var(--color-text-muted);
  }

  .ch-detail-tasks {
    display: flex;
    flex-direction: column;
    gap: 2px;
  }

  .ch-detail-task {
    display: flex;
    align-items: center;
    gap: 6px;
    padding: 4px 6px;
    cursor: pointer;
    font-size: 12px;
    border-radius: var(--radius-sm);
  }

  .ch-detail-task:hover {
    background: var(--color-bg-hover);
  }

  .ch-detail-task.ch-task-done {
    color: var(--color-accent);
  }

  .ch-task-check {
    flex-shrink: 0;
    width: 16px;
    text-align: center;
    font-weight: 700;
  }

  .ch-task-title {
    flex: 1;
    overflow: hidden;
    text-overflow: ellipsis;
    white-space: nowrap;
  }

  /* ── Challenge Panel (player) ── */

  .ch-panel {
    display: flex;
    flex-direction: column;
    gap: var(--space-1);
    padding: var(--space-2);
    height: 100%;
    overflow: hidden;
  }

  .ch-panel-top {
    display: flex;
    align-items: center;
    gap: var(--space-1);
    font-size: 11px;
  }

  .ch-panel-position {
    color: var(--color-text-muted);
    font-weight: 600;
    text-transform: uppercase;
    letter-spacing: 0.04em;
  }

  .ch-panel-progress {
    margin-left: auto;
    color: var(--color-accent);
    font-weight: 600;
    font-size: 10px;
  }

  .ch-panel-nav {
    display: flex;
    align-items: center;
    gap: var(--space-1);
    font-size: 12px;
  }

  .ch-panel-title {
    flex: 1;
    text-align: center;
    font-weight: 600;
    overflow: hidden;
    text-overflow: ellipsis;
    white-space: nowrap;
  }

  .ch-panel-content {
    flex: 1;
    min-height: 60px;
    overflow-y: auto;
    font-size: var(--challenge-font-size, 13px);
    line-height: 1.55;
    padding-right: 4px;
  }

  .ch-panel-content h1,
  .ch-panel-content h2,
  .ch-panel-content h3 {
    margin: 0 0 var(--space-1);
    line-height: 1.2;
    font-size: 13px;
  }

  .ch-panel-content p {
    margin: 0 0 var(--space-1);
  }

  .ch-panel-content ul,
  .ch-panel-content ol {
    margin: var(--space-1) 0;
    padding-left: 1.5em;
  }

  .ch-panel-content li {
    margin-bottom: 2px;
    line-height: 1.5;
  }

  .ch-panel-content li:last-child {
    margin-bottom: 0;
  }

  .ch-panel-content pre {
    margin: var(--space-1) 0;
    padding: var(--space-1) var(--space-2);
    background: var(--color-bg);
    border: 1px solid var(--color-border-light);
    border-radius: var(--radius-sm);
    overflow-x: auto;
    white-space: pre-wrap;
    font-size: var(--challenge-code-font-size, calc(var(--challenge-font-size, 13px) - 1px));
  }

  .ch-panel-content code {
    font-family: var(--font-mono);
    font-size: var(--challenge-code-font-size, calc(var(--challenge-font-size, 13px) - 1px));
    background: color-mix(in srgb, #f59e0b 15%, var(--color-bg));
    padding: 1px 4px;
    border-radius: 3px;
  }

  .ch-panel-content li code {
    font-size: inherit;
  }

  .ch-panel-content pre {
    font-size: var(--challenge-code-font-size, calc(var(--challenge-font-size, 13px) - 1px));
  }

  .ch-panel-content pre code {
    background: none;
    padding: 0;
  }

  .ch-panel-content strong {
    font-weight: 700;
  }

  .ch-panel-status {
    font-size: 11px;
    color: var(--color-text-muted);
    min-height: 16px;
  }

  .ch-panel-status.is-success {
    color: var(--color-accent);
  }

  .ch-panel-status.is-error {
    color: var(--color-error);
  }

  .ch-panel-toolbar {
    display: flex;
    gap: var(--space-1);
    align-items: center;
  }

  .ch-panel-top .ch-panel-font {
    margin-left: auto;
    display: flex;
    align-items: center;
    gap: 3px;
    flex-shrink: 0;
  }

  .ch-panel-font .ch-font-label {
    font-size: 9px;
    font-weight: 700;
    color: var(--color-text-muted);
    line-height: 1;
  }

  .ch-panel-font .ch-font-label-lg {
    font-size: 12px;
  }

  .ch-font-slider {
    width: 48px;
    height: 4px;
    -webkit-appearance: none;
    appearance: none;
    background: var(--color-border-light);
    border-radius: 2px;
    cursor: pointer;
    margin: 0;
    padding: 0;
    vertical-align: middle;
  }

  .ch-font-slider::-webkit-slider-thumb {
    -webkit-appearance: none;
    width: 12px;
    height: 12px;
    border-radius: 50%;
    background: var(--color-accent);
    border: none;
    cursor: pointer;
  }

  .ch-font-slider::-moz-range-thumb {
    width: 12px;
    height: 12px;
    border-radius: 50%;
    background: var(--color-accent);
    border: none;
    cursor: pointer;
  }

  /* ── Challenge Editor ── */

  .challenge-editor-body {
    max-height: 70vh;
    overflow-y: auto;
    padding: var(--space-2) var(--space-3);
  }

  .challenge-editor-section {
    margin-bottom: var(--space-3);
    padding-bottom: var(--space-2);
    border-bottom: 1px solid var(--color-border-light);
  }

  .challenge-editor-section:last-child {
    border-bottom: none;
    margin-bottom: 0;
  }

  .challenge-field {
    display: flex;
    flex-direction: column;
    gap: 3px;
    margin-bottom: var(--space-1);
  }

  .challenge-field label {
    font-size: 10px;
    font-weight: 600;
    text-transform: uppercase;
    letter-spacing: 0.04em;
    color: var(--color-text-muted);
  }

  .challenge-field-row {
    display: flex;
    gap: var(--space-2);
  }

  .challenge-field-header {
    display: flex;
    align-items: center;
    justify-content: space-between;
    margin-bottom: var(--space-1);
  }

  .challenge-field-header label {
    font-size: 11px;
    font-weight: 700;
    text-transform: uppercase;
    letter-spacing: 0.04em;
    color: var(--color-text);
  }

  .ce-input {
    font-size: 12px;
    font-family: var(--font-ui);
    padding: 4px 6px;
    border: 1px solid var(--color-border);
    border-radius: var(--radius-sm);
    background: var(--color-bg);
    color: var(--color-text);
    outline: none;
  }

  .ce-input:focus {
    border-color: var(--color-accent);
  }

  .ce-textarea {
    font-size: 12px;
    font-family: var(--font-ui);
    padding: 4px 6px;
    border: 1px solid var(--color-border);
    border-radius: var(--radius-sm);
    background: var(--color-bg);
    color: var(--color-text);
    outline: none;
    resize: vertical;
  }

  .ce-textarea:focus {
    border-color: var(--color-accent);
  }

  .ce-task {
    padding: var(--space-2);
    margin-bottom: var(--space-2);
    border: 1px solid var(--color-border-light);
    border-radius: var(--radius-md);
    background: var(--color-bg);
  }

  .ce-task-header {
    display: flex;
    align-items: center;
    justify-content: space-between;
    margin-bottom: var(--space-1);
    font-size: 12px;
  }

  .ce-task-fields {
    display: flex;
    flex-direction: column;
    gap: 2px;
  }

  .challenge-editor-footer {
    display: flex;
    gap: var(--space-1);
    justify-content: flex-end;
    padding: var(--space-2) var(--space-3);
    border-top: 1px solid var(--color-border-light);
  }

  .ce-check-params {
    padding-left: var(--space-3);
    border-left: 2px solid var(--color-border-light);
  }
}