:root {
  --color-canvas: #F7F6F2;
  --color-surface: #FFFFFF;
  --color-surface-alt: #EFEDE6;
  --color-border: #DDD9CE;
  --color-text: #262420;
  --color-text-muted: #6B6558;
  --color-accent: #8A5A44;
  --color-accent-hover: #714936;
  --color-accent-contrast: #FFFFFF;
  --color-danger: #B3452E;
  --color-danger-hover: #943A27;
  --color-focus: #8A5A44;
  --font-sans: "Inter", "Segoe UI", system-ui, sans-serif;
  --font-mono: "JetBrains Mono", "Fira Code", monospace;
  --radius-sm: 4px;
  --radius-md: 8px;
  --radius-lg: 14px;
  --shadow-sm: 0 1px 2px rgba(38,36,32,0.08);
  --shadow-md: 0 4px 12px rgba(38,36,32,0.12);
  --transition-fast: 120ms ease;
  --transition-med: 220ms ease;
}

[data-theme="dark"] {
  --color-canvas: #1C1B18;
  --color-surface: #252320;
  --color-surface-alt: #2E2B27;
  --color-border: #3C3832;
  --color-text: #ECE8DE;
  --color-text-muted: #A69E8D;
  --color-accent: #D2926F;
  --color-accent-hover: #E3A581;
  --color-accent-contrast: #1C1B18;
  --color-danger: #E2725A;
  --color-danger-hover: #EF8468;
  --color-focus: #D2926F;
  --shadow-sm: 0 1px 2px rgba(0,0,0,0.3);
  --shadow-md: 0 4px 12px rgba(0,0,0,0.4);
}

* {
  box-sizing: border-box;
}

html, body {
  margin: 0;
  padding: 0;
  height: 100%;
}

body {
  background: var(--color-canvas);
  color: var(--color-text);
  font-family: var(--font-sans);
  font-size: 15px;
  line-height: 1.5;
  transition: background var(--transition-med), color var(--transition-med);
}

button, input, textarea {
  font-family: inherit;
  font-size: inherit;
  color: inherit;
}

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

.app-shell {
  min-height: 100vh;
  display: flex;
  flex-direction: column;
}

/* Header */
.app-header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 0.9rem 1.5rem;
  background: var(--color-surface);
  border-bottom: 1px solid var(--color-border);
}

.app-header__brand {
  display: flex;
  align-items: center;
  gap: 0.6rem;
}

.app-header__logo {
  font-weight: 700;
  font-size: 1.3rem;
  color: var(--color-accent);
}

.app-header__title {
  font-size: 1.1rem;
  font-weight: 600;
  margin: 0;
}

.app-header__actions {
  display: flex;
  gap: 0.5rem;
}

/* Buttons */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 0.4rem;
  padding: 0.5rem 0.9rem;
  border-radius: var(--radius-md);
  border: 1px solid transparent;
  cursor: pointer;
  font-weight: 500;
  transition: background var(--transition-fast), border-color var(--transition-fast), transform var(--transition-fast);
}

.btn:active {
  transform: translateY(1px);
}

.btn--primary {
  background: var(--color-accent);
  color: var(--color-accent-contrast);
  border-color: var(--color-accent);
}

.btn--primary:hover {
  background: var(--color-accent-hover);
  border-color: var(--color-accent-hover);
}

.btn--ghost {
  background: transparent;
  color: var(--color-text);
  border-color: var(--color-border);
}

.btn--ghost:hover {
  background: var(--color-surface-alt);
}

.btn--danger {
  background: var(--color-danger);
  color: #fff;
  border-color: var(--color-danger);
}

.btn--danger:hover {
  background: var(--color-danger-hover);
  border-color: var(--color-danger-hover);
}

/* File tabs bar */
.file-tabs-bar {
  display: flex;
  align-items: center;
  gap: 0.4rem;
  padding: 0.5rem 1rem;
  background: var(--color-surface-alt);
  border-bottom: 1px solid var(--color-border);
  overflow-x: auto;
  min-height: 2.6rem;
}

.file-tabs-bar:empty::after {
  content: "No open files yet";
  color: var(--color-text-muted);
  font-size: 0.85rem;
  padding: 0.3rem 0.4rem;
}

.file-tab {
  display: inline-flex;
  align-items: center;
  gap: 0.5rem;
  padding: 0.4rem 0.7rem;
  background: var(--color-surface);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-sm);
  cursor: pointer;
  color: var(--color-text);
  white-space: nowrap;
  transition: background var(--transition-fast), border-color var(--transition-fast);
}

.file-tab:hover {
  background: var(--color-canvas);
}

.file-tab--active {
  border-color: var(--color-accent);
  background: var(--color-canvas);
  box-shadow: inset 0 -2px 0 var(--color-accent);
  font-weight: 600;
}

.file-tab__name {
  max-width: 11rem;
  overflow: hidden;
  text-overflow: ellipsis;
}

.file-tab__close {
  background: none;
  border: none;
  color: var(--color-text-muted);
  cursor: pointer;
  font-size: 0.9rem;
  line-height: 1;
  padding: 0.1rem 0.25rem;
  border-radius: var(--radius-sm);
}

.file-tab__close:hover {
  background: var(--color-danger);
  color: #fff;
}

/* Workspace */
.workspace {
  flex: 1;
  display: flex;
  min-height: 0;
}

/* Empty state */
.empty-state {
  flex: 1;
  display: flex;
  align-items: center;
  justify-content: center;
  padding: 2rem;
}

.empty-state__card {
  text-align: center;
  background: var(--color-surface);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-lg);
  padding: 2.5rem 2rem;
  max-width: 26rem;
  box-shadow: var(--shadow-sm);
}

.empty-state__icon {
  font-size: 2.5rem;
  margin: 0 0 0.5rem;
}

.empty-state__title {
  margin: 0 0 0.5rem;
  font-size: 1.2rem;
}

.empty-state__hint {
  color: var(--color-text-muted);
  margin: 0 0 1.5rem;
}

/* Editor / preview split */
.editor-preview {
  flex: 1;
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 1px;
  background: var(--color-border);
  min-height: 0;
}

.pane {
  display: flex;
  flex-direction: column;
  background: var(--color-surface);
  min-height: 0;
}

.pane__header {
  padding: 0.6rem 1rem;
  border-bottom: 1px solid var(--color-border);
}

.pane__label {
  font-size: 0.8rem;
  text-transform: uppercase;
  letter-spacing: 0.04em;
  color: var(--color-text-muted);
  font-weight: 600;
}

.editor-textarea {
  flex: 1;
  resize: none;
  border: none;
  background: transparent;
  color: var(--color-text);
  padding: 1rem;
  font-family: var(--font-mono);
  font-size: 0.95rem;
  line-height: 1.6;
}

.editor-textarea:focus-visible {
  outline: none;
  box-shadow: inset 0 0 0 2px var(--color-focus);
}

.preview-pane {
  flex: 1;
  overflow-y: auto;
  padding: 1rem 1.25rem;
}

.preview-pane h1,
.preview-pane h2,
.preview-pane h3 {
  margin-top: 1.2em;
  margin-bottom: 0.4em;
}

.preview-pane h1:first-child,
.preview-pane h2:first-child,
.preview-pane h3:first-child {
  margin-top: 0;
}

.preview-pane p {
  margin: 0.5em 0;
}

.preview-pane code {
  background: var(--color-surface-alt);
  padding: 0.1em 0.35em;
  border-radius: 3px;
  font-family: var(--font-mono);
  font-size: 0.9em;
}

.preview-pane pre {
  background: var(--color-surface-alt);
  padding: 0.8em 1em;
  border-radius: var(--radius-sm);
  overflow-x: auto;
}

.preview-pane pre code {
  background: none;
  padding: 0;
}

.preview-pane blockquote {
  border-left: 3px solid var(--color-accent);
  margin: 0.6em 0;
  padding: 0.2em 1em;
  color: var(--color-text-muted);
}

.preview-pane ul, .preview-pane ol {
  padding-left: 1.4em;
}

.preview-pane a {
  color: var(--color-accent);
}

/* Footer */
.app-footer {
  padding: 0.5rem 1.5rem;
  background: var(--color-surface);
  border-top: 1px solid var(--color-border);
  color: var(--color-text-muted);
  font-size: 0.8rem;
}

/* Dialogs */
.confirm-dialog {
  border: 1px solid var(--color-border);
  border-radius: var(--radius-lg);
  padding: 0;
  background: var(--color-surface);
  color: var(--color-text);
  box-shadow: var(--shadow-md);
  max-width: 26rem;
  width: 90vw;
}

.confirm-dialog::backdrop {
  background: rgba(0, 0, 0, 0.4);
}

.confirm-dialog__form {
  display: flex;
  flex-direction: column;
  gap: 0.8rem;
  padding: 1.5rem;
}

.confirm-dialog__title {
  margin: 0;
  font-size: 1.1rem;
}

.confirm-dialog__message {
  color: var(--color-text-muted);
  margin: 0;
}

.confirm-dialog__actions {
  display: flex;
  justify-content: flex-end;
  gap: 0.6rem;
  margin-top: 0.5rem;
}

.text-input {
  padding: 0.5rem 0.7rem;
  border: 1px solid var(--color-border);
  border-radius: var(--radius-sm);
  background: var(--color-canvas);
  color: var(--color-text);
}

.text-input:focus-visible {
  outline: none;
  box-shadow: 0 0 0 2px var(--color-focus);
}

.inline-error {
  color: var(--color-danger);
  font-size: 0.85rem;
  margin: 0;
}

/* Responsive breakpoints */
@media (max-width: 900px) {
  .editor-preview {
    grid-template-columns: 1fr;
    grid-template-rows: 1fr 1fr;
  }
}

@media (max-width: 560px) {
  .app-header {
    flex-direction: column;
    align-items: flex-start;
    gap: 0.6rem;
  }

  .app-header__actions {
    width: 100%;
  }

  .app-header__actions .btn {
    width: 100%;
  }

  .file-tab__name {
    max-width: 7rem;
  }

  .empty-state__card {
    padding: 1.5rem 1.2rem;
  }
}

@media (prefers-reduced-motion: reduce) {
  * {
    transition: none !important;
    animation: none !important;
  }
}

/* generated: an element marked hidden stays hidden whatever its class sets */
[hidden] { display: none !important; }