.prep-body {
  min-height: 100vh;
  overflow: hidden;
  background: var(--bg-0);
  color: var(--tx-1);
}

.prep-workspace[hidden],
.prep-empty-state[hidden],
.prep-compact-form[hidden],
.prep-editor-form[hidden],
.prep-editor-empty[hidden] {
  display: none;
}

.prep-header {
  height: 64px;
  padding: 0 22px;
  border-bottom: 1px solid var(--line);
  background: var(--bg-1);
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 20px;
}

.prep-header-brand,
.prep-header-actions,
.prep-button-row {
  display: flex;
  align-items: center;
  gap: 10px;
}

.prep-header-brand > span,
.prep-user {
  color: var(--tx-3);
  font-size: 12px;
}

.prep-workspace {
  height: calc(100vh - 64px);
  display: grid;
  grid-template-columns: 300px minmax(440px, 1fr) minmax(360px, .9fr);
  background: var(--bg-0);
}

.prep-library,
.prep-editor-pane,
.prep-preview-pane {
  min-width: 0;
  overflow-y: auto;
}

.prep-library {
  padding: 20px;
  border-right: 1px solid var(--line);
  background: var(--bg-1);
}

.prep-editor-pane {
  border-right: 1px solid var(--line);
}

.prep-preview-pane {
  padding: 20px;
  background: var(--bg-1);
}

.prep-panel-heading,
.prep-editor-toolbar {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 12px;
}

.prep-panel-heading h2 {
  margin-top: 5px;
  font: 600 17px/1.2 var(--font-display);
}

.prep-kicker {
  color: var(--accent);
  font: 600 9px/1 var(--font-mono);
  letter-spacing: .13em;
}

.prep-subheading {
  margin-top: 28px;
  padding-top: 20px;
  border-top: 1px solid var(--line);
}

.prep-list,
.prep-outline,
.prep-versions {
  display: grid;
  gap: 7px;
  margin-top: 12px;
}

.prep-list-item,
.prep-outline-item,
.prep-version-item {
  width: 100%;
  padding: 11px 12px;
  border: 1px solid var(--line);
  background: var(--bg-2);
  color: var(--tx-2);
  text-align: left;
  cursor: pointer;
}

.prep-list-item:hover,
.prep-outline-item:hover,
.prep-list-item.selected,
.prep-outline-item.selected {
  border-color: var(--accent);
  color: var(--tx-1);
  background: var(--accent-dim);
}

.prep-list-item strong,
.prep-outline-item strong {
  display: block;
  margin-bottom: 4px;
  color: inherit;
}

.prep-item-meta {
  color: var(--tx-3);
  font: 500 10px/1.5 var(--font-mono);
}

.prep-outline-block {
  margin-left: 16px;
}

.prep-outline-block strong {
  font-weight: 400;
}

.prep-compact-form,
.prep-editor-form {
  display: grid;
  gap: 14px;
}

.prep-compact-form {
  margin-top: 12px;
  padding: 14px;
  border: 1px solid var(--accent-line);
  background: var(--accent-dim);
}

.prep-compact-form label,
.prep-editor-form label,
.prep-field {
  display: grid;
  gap: 7px;
  color: var(--tx-2);
  font-size: 11px;
}

.prep-compact-form input,
.prep-compact-form textarea,
.prep-editor-form input,
.prep-editor-form textarea,
.prep-editor-form select,
.prep-field input,
.prep-field textarea,
.prep-field select {
  width: 100%;
  box-sizing: border-box;
  padding: 11px 12px;
  border: 1px solid var(--line-strong);
  background: var(--bg-0);
  color: var(--tx-1);
  outline: 0;
  font: 13px/1.6 var(--font-body);
  resize: vertical;
}

.prep-editor-toolbar {
  position: sticky;
  top: 0;
  z-index: 5;
  min-height: 64px;
  padding: 12px 20px;
  border-bottom: 1px solid var(--line);
  background: var(--bg-1);
}

.prep-status-badge {
  display: inline-block;
  padding: 5px 8px;
  border: 1px solid var(--accent-line);
  color: var(--accent);
  font: 600 10px/1 var(--font-mono);
}

.prep-save-status {
  margin-left: 8px;
  color: var(--tx-3);
  font-size: 11px;
}

.prep-editor-form {
  padding: 24px;
}

.prep-editor-empty,
.prep-empty-state {
  padding: 70px 30px;
  color: var(--tx-2);
  text-align: center;
}

.prep-empty-state {
  width: min(560px, calc(100% - 32px));
  margin: 80px auto;
  border: 1px solid var(--line);
  background: var(--bg-1);
}

.prep-empty-state h1,
.prep-editor-empty h1 {
  margin: 12px 0;
  color: var(--tx-1);
}

.prep-empty-state p {
  margin-bottom: 22px;
}

.prep-readonly {
  padding: 11px 12px;
  border: 1px solid var(--line);
  color: var(--tx-3);
  font-family: var(--font-mono);
}

.prep-block-adder {
  display: grid;
  grid-template-columns: minmax(0, 1fr) auto auto;
  align-items: end;
  gap: 10px;
  padding: 16px;
  border: 1px solid var(--accent-line);
  background: var(--accent-dim);
}

.question-picker-dialog {
  width: min(980px, calc(100% - 32px));
  max-height: min(820px, calc(100vh - 48px));
  padding: 0;
  border: 1px solid var(--accent-line);
  background: var(--bg-1);
  color: var(--tx-1);
}

.question-picker-dialog::backdrop {
  background: rgba(5, 5, 10, .82);
  backdrop-filter: blur(4px);
}

.question-picker-shell {
  padding: 22px;
}

.question-picker-header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 16px;
  padding-bottom: 16px;
  border-bottom: 1px solid var(--line);
}

.question-picker-header h2 {
  margin-top: 6px;
  font: 600 22px/1.2 var(--font-display);
}

.question-picker-filters {
  display: grid;
  grid-template-columns: minmax(220px, 1.6fr) repeat(3, minmax(120px, .7fr)) auto;
  gap: 8px;
  margin: 18px 0 10px;
}

.question-picker-filters input,
.question-picker-filters select {
  width: 100%;
  box-sizing: border-box;
  padding: 10px;
  border: 1px solid var(--line-strong);
  background: var(--bg-0);
  color: var(--tx-1);
}

.question-picker-results {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 10px;
  max-height: 550px;
  overflow-y: auto;
  padding: 4px 2px;
}

.question-picker-item {
  padding: 16px;
  border: 1px solid var(--line);
  background: var(--bg-2);
}

.question-picker-item:hover {
  border-color: var(--accent);
  background: var(--accent-dim);
}

.question-picker-item h3 {
  margin-bottom: 8px;
  font-size: 15px;
}

.question-picker-item p {
  color: var(--tx-2);
  line-height: 1.65;
}

.question-picker-item-meta {
  margin: 10px 0;
  color: var(--tx-3);
  font: 500 10px/1.5 var(--font-mono);
}

.prep-block-editor {
  display: grid;
  gap: 14px;
  padding: 18px;
  border: 1px solid var(--line);
  background: var(--bg-1);
}

.prep-block-editor h3 {
  font-size: 17px;
}

.prep-editor-actions {
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
  padding-top: 8px;
  border-top: 1px solid var(--line);
}

.prep-muted,
.prep-preview-header p {
  color: var(--tx-3);
  line-height: 1.7;
}

.prep-preview-paper {
  margin-top: 14px;
  padding: 26px;
  border: 1px solid var(--line);
  background: var(--bg-0);
}

.prep-preview-header {
  padding-bottom: 24px;
  margin-bottom: 26px;
  border-bottom: 1px solid var(--line);
}

.prep-preview-header h1 {
  margin: 8px 0 12px;
  font: 600 28px/1.2 var(--font-display);
}

.prep-preview-paper .lecture-section-heading {
  grid-template-columns: 34px minmax(0, 1fr);
}

.prep-preview-paper .lecture-section-heading h2 {
  font-size: 19px;
}

.prep-preview-paper .lecture-block {
  padding: 16px;
}

.prep-version-item {
  display: flex;
  justify-content: space-between;
  align-items: center;
  gap: 8px;
  cursor: default;
  font-size: 11px;
}

.prep-version-item button {
  padding: 5px 7px;
}

@media (max-width: 1180px) {
  .prep-body { overflow: auto; }
  .prep-workspace {
    height: auto;
    grid-template-columns: 280px minmax(0, 1fr);
  }
  .prep-preview-pane {
    grid-column: 1 / -1;
    border-top: 1px solid var(--line);
  }
}

@media (max-width: 760px) {
  .prep-header { height: auto; padding: 14px 16px; align-items: flex-start; }
  .prep-header-actions { flex-wrap: wrap; justify-content: flex-end; }
  .prep-workspace { grid-template-columns: 1fr; }
  .prep-library,
  .prep-editor-pane { border-right: 0; border-bottom: 1px solid var(--line); }
  .prep-editor-toolbar { position: static; align-items: flex-start; }
  .prep-editor-toolbar,
  .prep-panel-heading { flex-wrap: wrap; }
  .prep-block-adder { grid-template-columns: 1fr; }
  .question-picker-filters { grid-template-columns: 1fr 1fr; }
  .question-picker-results { grid-template-columns: 1fr; }
}