:root {
  --uml-text: #000000;
  --uml-line: #181818;
  --uml-canvas: transparent;
  --uml-node: #f1f1f1;
  --uml-note: #feffdd;
  --uml-partition: transparent;
  --uml-participant: #e2e2f0;
  --uml-activation: #ffffff;
  --uml-lifeline: #777777;
  --uml-divider: #777777;
  --uml-divider-title: #f6f6f6;
  --uml-delay: #777777;
  --uml-reference-tab: #eeeeee;
  --uml-page-break: #555555;
  --uml-transparent: none;
  --uml-spot-abstract: #a9dcdf;
  --uml-spot-interface: #b4a7e5;
  --uml-spot-enum: #eb937f;
  --uml-spot-annotation: #e3664a;
  --uml-spot-class: #add1b2;
  --uml-visibility-public-stroke: #038048;
  --uml-visibility-public-fill: #84be84;
  --uml-visibility-private-stroke: #c82930;
  --uml-visibility-private-fill: #f24d5c;
  --uml-visibility-protected-stroke: #b38d22;
  --uml-visibility-protected-fill: #ffff44;
  --uml-visibility-package-stroke: #1963a0;
  --uml-visibility-package-fill: #4177af;

  --app-bg: #f8fafc;
  --editor-bg: #ffffff;
  --preview-bg: #ffffff;
  --text: #1f2937;
  --text-strong: #0f172a;
  --title-color: #475569;
  --border: #cbd5e1;
  --item-placeholder: #94a3b8;
  --active-bg: #2563eb;
  --active-text: #ffffff;
  --rui-border: #d1d5db;
}

[data-theme="dark"] {
  --uml-text: #e2e8f0;
  --uml-line: #94a3b8;
  --uml-canvas: transparent;
  --uml-node: #1e293b;
  --uml-note: #3b341a;
  --uml-partition: transparent;
  --uml-participant: #334155;
  --uml-activation: #1e293b;
  --uml-lifeline: #64748b;
  --uml-divider: #94a3b8;
  --uml-divider-title: #1e293b;
  --uml-delay: #94a3b8;
  --uml-reference-tab: #334155;
  --uml-page-break: #64748b;
  --uml-transparent: none;
  --uml-spot-abstract: #155e75;
  --uml-spot-interface: #4338ca;
  --uml-spot-enum: #9a3412;
  --uml-spot-annotation: #9f1239;
  --uml-spot-class: #166534;
  --uml-visibility-public-stroke: #4ade80;
  --uml-visibility-public-fill: #14532d;
  --uml-visibility-private-stroke: #f87171;
  --uml-visibility-private-fill: #7f1d1d;
  --uml-visibility-protected-stroke: #facc15;
  --uml-visibility-protected-fill: #713f12;
  --uml-visibility-package-stroke: #60a5fa;
  --uml-visibility-package-fill: #1e3a8a;

  --app-bg: #0f172a;
  --editor-bg: #0f172a;
  --preview-bg: #0f172a;
  --text: #e2e8f0;
  --text-strong: #f1f5f9;
  --title-color: #94a3b8;
  --border: #334155;
  --item-placeholder: #64748b;
  --active-bg: #3b82f6;
  --active-text: #ffffff;
  --rui-border: #334155;
}

* {
  box-sizing: border-box;
}

body {
  margin: 0;
  min-height: 100vh;
  color: var(--text);
  font-family: ui-monospace, SFMono-Regular, Menlo, Monaco, Consolas, monospace;
  background: var(--app-bg);
}

#app {
  height: 100vh;
}

.file-panel,
.editor-panel,
.preview-panel {
  min-width: 0;
  min-height: 0;
  height: 100%;
  padding: 16px;
}

.editor-panel {
  display: flex;
  flex-direction: column;
  background: var(--editor-bg);
}

.preview-panel {
  display: flex;
  flex-direction: column;
  background: var(--app-bg);
}

.panel-header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  margin-bottom: 12px;
}

.panel-header .panel-title {
  margin: 0;
}

.panel-title {
  margin: 0 0 12px;
  color: var(--title-color);
  font-family: system-ui, sans-serif;
  font-size: 0.75rem;
  font-weight: 700;
  letter-spacing: 0;
  text-transform: uppercase;
}

.theme-toggle {
  padding: 4px 10px;
  border: 1px solid var(--border);
  border-radius: 4px;
  color: var(--title-color);
  background: transparent;
  font-family: system-ui, sans-serif;
  font-size: 0.75rem;
  font-weight: 700;
  text-transform: uppercase;
  cursor: pointer;
}

.theme-toggle:hover {
  color: var(--text-strong);
  border-color: var(--text-strong);
}

.file-list {
  margin: 0;
  padding: 0;
  list-style: none;
}

.file-item {
  padding: 8px 10px;
  border-radius: 4px;
  font-size: 0.875rem;
}

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

.file-category {
  margin-top: 12px;
  margin-bottom: 4px;
  color: var(--title-color);
  font-family: system-ui, sans-serif;
  font-size: 0.75rem;
  font-weight: 700;
  text-transform: uppercase;
}

.file-placeholder {
  padding: 8px 10px;
  color: var(--item-placeholder);
  font-size: 0.875rem;
}

.editor,
.preview {
  flex: 1;
  width: 100%;
  min-height: 0;
  margin: 0;
  padding: 12px;
  border: 1px solid var(--border);
  border-radius: 4px;
  font-family: ui-monospace, SFMono-Regular, Menlo, Monaco, Consolas, monospace;
  font-size: 0.875rem;
  line-height: 1.6;
}

.editor {
  resize: none;
  color: var(--text-strong);
  background: var(--editor-bg);
}

.editor:focus {
  outline: 2px solid var(--active-bg);
  outline-offset: -1px;
}

.preview {
  overflow: auto;
  white-space: pre-wrap;
  color: var(--text-strong);
  background: var(--preview-bg);
}

.preview-message {
  padding: 8px;
  color: var(--item-placeholder);
  font-size: 0.875rem;
}