:root {
  --bg: #ffffff;
  --bg-alt: #f5f5f7;
  --border: #e2e2e6;
  --text: #1c1c1e;
  --text-dim: #6e6e73;
  --accent: #3a6df0;
  --danger: #d64545;
}

@media (prefers-color-scheme: dark) {
  :root {
    --bg: #1e1e20;
    --bg-alt: #26262a;
    --border: #38383c;
    --text: #f0f0f2;
    --text-dim: #9a9a9f;
    --accent: #6a92ff;
    --danger: #ff6b6b;
  }
}

* { box-sizing: border-box; }

html, body {
  height: 100%;
  margin: 0;
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Helvetica, Arial, sans-serif;
  color: var(--text);
  background: var(--bg);
}

.app {
  display: flex;
  height: 100vh;
}

.sidebar {
  width: 280px;
  min-width: 280px;
  background: var(--bg-alt);
  border-right: 1px solid var(--border);
  display: flex;
  flex-direction: column;
  padding: 12px;
  overflow: hidden;
  transition: width 0.15s ease, min-width 0.15s ease, padding 0.15s ease, border-color 0.15s ease;
}

.app.sidebar-collapsed .sidebar {
  width: 0;
  min-width: 0;
  padding: 12px 0;
  border-right-color: transparent;
}

.app.sidebar-collapsed .sidebar > * {
  opacity: 0;
  pointer-events: none;
}

.sidebar-header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  margin-bottom: 10px;
}

.sidebar-header h1 {
  font-size: 16px;
  margin: 0;
  font-weight: 600;
}

#new-note {
  background: var(--accent);
  color: #fff;
  border: none;
  border-radius: 6px;
  padding: 6px 10px;
  font-size: 13px;
  cursor: pointer;
}

#search {
  width: 100%;
  padding: 7px 10px;
  margin-bottom: 8px;
  border-radius: 6px;
  border: 1px solid var(--border);
  background: var(--bg);
  color: var(--text);
  font-size: 13px;
}

.note-list {
  list-style: none;
  margin: 0;
  padding: 0;
  overflow-y: auto;
  flex: 1;
}

.note-item {
  padding: 10px 8px;
  border-radius: 6px;
  cursor: pointer;
  margin-bottom: 2px;
}

.note-item:hover {
  background: var(--border);
}

.note-item.active {
  background: var(--accent);
  color: #fff;
}

.note-item .note-title {
  font-size: 13.5px;
  font-weight: 600;
  white-space: nowrap;
  overflow: hidden;
  text-overflow: ellipsis;
}

.note-item .note-meta {
  font-size: 11.5px;
  opacity: 0.7;
  margin-top: 2px;
  white-space: nowrap;
  overflow: hidden;
  text-overflow: ellipsis;
}

.sidebar-footer {
  display: flex;
  gap: 6px;
  padding-top: 8px;
  border-top: 1px solid var(--border);
}

.sidebar-footer button,
.sidebar-footer label {
  flex: 1;
  text-align: center;
  font-size: 12px;
  padding: 6px 4px;
  border-radius: 6px;
  border: 1px solid var(--border);
  background: var(--bg);
  color: var(--text);
  cursor: pointer;
}

#delete-note {
  color: var(--danger);
}

.editor-pane {
  flex: 1;
  display: flex;
  flex-direction: column;
  min-width: 0;
}

.editor-topbar {
  display: flex;
  align-items: center;
  gap: 12px;
  padding: 14px 24px 6px;
}

#sidebar-toggle {
  border: 1px solid var(--border);
  background: var(--bg);
  color: var(--text);
  border-radius: 6px;
  width: 30px;
  height: 30px;
  font-size: 14px;
  line-height: 1;
  cursor: pointer;
  flex: none;
}

#title-input {
  flex: 1;
  border: none;
  outline: none;
  background: transparent;
  color: var(--text);
  font-size: 24px;
  font-weight: 700;
}

#history-btn,
#checkpoint-btn {
  border: 1px solid var(--border);
  background: var(--bg);
  color: var(--text);
  border-radius: 6px;
  padding: 6px 10px;
  font-size: 12.5px;
  cursor: pointer;
  flex: none;
  white-space: nowrap;
  position: relative;
}

#checkpoint-btn.dirty {
  border-color: var(--accent);
  color: var(--accent);
}

#checkpoint-btn.dirty::after {
  content: "";
  position: absolute;
  top: -3px;
  right: -3px;
  width: 8px;
  height: 8px;
  border-radius: 50%;
  background: var(--accent);
  border: 2px solid var(--bg);
}

.save-status {
  font-size: 12px;
  color: var(--text-dim);
  white-space: nowrap;
}

#editor {
  flex: 1;
  overflow-y: auto;
  border: none !important;
}

.ql-toolbar.ql-snow {
  border: none !important;
  border-bottom: 1px solid var(--border) !important;
  padding: 8px 24px !important;
}

.ql-container.ql-snow {
  border: none !important;
  font-size: 16px;
}

.ql-editor {
  padding: 16px 24px 60px !important;
  min-height: 100%;
}

.ql-editor.ql-blank::before {
  color: var(--text-dim);
  font-style: normal;
}

@media (prefers-color-scheme: dark) {
  .ql-snow .ql-stroke { stroke: var(--text); }
  .ql-snow .ql-fill { fill: var(--text); }
  .ql-snow .ql-picker { color: var(--text); }
  .ql-snow .ql-picker-options { background: var(--bg-alt); }
}

.empty-state {
  display: flex;
  align-items: center;
  justify-content: center;
  height: 100%;
  color: var(--text-dim);
  font-size: 14px;
}

/* Version history modal */

.modal-overlay {
  position: fixed;
  inset: 0;
  background: rgba(0, 0, 0, 0.4);
  display: flex;
  align-items: center;
  justify-content: center;
  z-index: 100;
}

.modal-overlay[hidden] {
  display: none;
}

.modal {
  width: 560px;
  max-width: 92vw;
  max-height: 82vh;
  background: var(--bg);
  border-radius: 10px;
  border: 1px solid var(--border);
  display: flex;
  flex-direction: column;
  overflow: hidden;
  box-shadow: 0 12px 40px rgba(0, 0, 0, 0.25);
}

.modal-header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 14px 18px;
  border-bottom: 1px solid var(--border);
}

.modal-header h2 {
  font-size: 16px;
  margin: 0;
}

#history-close {
  border: none;
  background: transparent;
  color: var(--text-dim);
  font-size: 20px;
  line-height: 1;
  cursor: pointer;
  padding: 2px 6px;
}

.modal-body {
  overflow-y: auto;
  padding: 12px 18px 18px;
}

.history-stats {
  display: flex;
  gap: 16px;
  font-size: 12.5px;
  color: var(--text-dim);
  margin-bottom: 12px;
  padding-bottom: 12px;
  border-bottom: 1px solid var(--border);
}

.history-stats b {
  color: var(--text);
}

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

.history-entry {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 10px;
  padding: 10px 8px;
  border-radius: 6px;
  cursor: pointer;
}

.history-entry:hover {
  background: var(--bg-alt);
}

.history-entry-main {
  min-width: 0;
}

.history-entry-time {
  font-size: 13px;
  font-weight: 600;
}

.history-entry-sub {
  font-size: 11.5px;
  color: var(--text-dim);
  white-space: nowrap;
  overflow: hidden;
  text-overflow: ellipsis;
}

.history-entry-delta {
  font-size: 11.5px;
  font-weight: 600;
  flex: none;
  padding: 2px 7px;
  border-radius: 10px;
  background: var(--bg-alt);
  color: var(--text-dim);
}

.history-entry-delta.positive {
  color: #1a8a4a;
}

.history-entry-delta.negative {
  color: var(--danger);
}

.history-empty {
  color: var(--text-dim);
  font-size: 13px;
  padding: 20px 8px;
  text-align: center;
}

.history-preview-wrap {
  border-top: 1px solid var(--border);
  display: flex;
  flex-direction: column;
  max-height: 60vh;
}

.history-preview-wrap[hidden] {
  display: none;
}

.history-preview-header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 10px;
  padding: 10px 18px;
  border-bottom: 1px solid var(--border);
}

#history-preview-meta {
  font-size: 12.5px;
  color: var(--text-dim);
}

.history-preview-actions {
  display: flex;
  gap: 8px;
  flex: none;
}

.history-preview-actions button {
  font-size: 12px;
  padding: 6px 10px;
  border-radius: 6px;
  border: 1px solid var(--border);
  background: var(--bg);
  color: var(--text);
  cursor: pointer;
}

.primary-btn {
  background: var(--accent) !important;
  color: #fff !important;
  border-color: var(--accent) !important;
}

#history-preview {
  overflow-y: auto;
  padding: 14px 18px;
}

#history-preview .ql-editor {
  padding: 0 !important;
}

.zen-toggle {
  position: fixed;
  bottom: 16px;
  right: 16px;
  z-index: 10;
  width: 32px;
  height: 32px;
  border-radius: 6px;
  border: 1px solid var(--border);
  background: var(--bg);
  color: var(--text);
  cursor: pointer;
  font-size: 16px;
  line-height: 1;
  opacity: 0.55;
}

.zen-toggle:hover {
  opacity: 1;
}

.app.zen .sidebar,
.app.zen .editor-topbar,
.app.zen .ql-toolbar.ql-snow {
  display: none;
}

.app.zen .editor-pane {
  align-items: center;
}

.app.zen #editor {
  max-width: 720px;
  width: 100%;
  margin: 0 auto;
  padding-top: 48px;
}