* {
  box-sizing: border-box;
}

body {
  margin: 0;
  font-family: system-ui, -apple-system, sans-serif;
  background: #1e1e1e;
  color: #cccccc;
  height: 100vh;
  height: 100dvh;
  display: flex;
  flex-direction: column;
}

body.modal-open {
  overflow: hidden;
}

header {
  padding: 0.6rem 1rem;
  border-bottom: 1px solid #333;
  display: flex;
  flex-direction: column;
  gap: 0.5rem;
  flex-shrink: 0;
}

.header-brand {
  display: flex;
  align-items: center;
  gap: 0.75rem;
  flex-wrap: wrap;
}

.title-block h1 {
  margin: 0;
  font-size: 1.05rem;
  font-weight: 600;
}

.title-block p {
  margin: 0.1rem 0 0;
  font-size: 0.7rem;
  color: #666;
}

/* ── Primary mode switch (segmented control) ── */
.mode-switch {
  display: flex;
  border: 1px solid #444;
  border-radius: 5px;
  overflow: hidden;
  flex-shrink: 0;
}

.mode-btn {
  background: #2d2d2d;
  border: none;
  color: #999;
  padding: 0.28rem 0.75rem;
  font-size: 0.8rem;
  font-weight: 500;
  cursor: pointer;
  transition: background 0.12s, color 0.12s;
  white-space: nowrap;
}

.mode-btn + .mode-btn {
  border-left: 1px solid #444;
}

.mode-btn:hover:not(.active) {
  background: #383838;
  color: #bbb;
}

.mode-btn.active {
  background: #007acc;
  color: #fff;
}

.mode-btn:focus-visible {
  outline: 2px solid #007acc;
  outline-offset: 2px;
}

/* ─────────────────────────────── */

.header-toolbar {
  display: flex;
  align-items: center;
  gap: 0.65rem;
  flex-wrap: wrap;
}

.header-toolbar label {
  display: flex;
  align-items: center;
  gap: 0.35rem;
  font-size: 0.8125rem;
  color: #aaa;
  cursor: pointer;
}

.header-toolbar select,
.header-toolbar input[type="text"] {
  background: #2d2d2d;
  border: 1px solid #444;
  color: #cccccc;
  padding: 0.25rem 0.5rem;
  border-radius: 4px;
  font-size: 0.8125rem;
}

.header-toolbar input[type="text"] {
  font-family: ui-monospace, monospace;
  width: 8rem;
}

.header-toolbar select {
  min-width: 11rem;
}

.entry-rule-wrap {
  display: flex;
  flex-direction: row;
  align-items: center;
  gap: 0.35rem;
}

.entry-rule-wrap > label {
  font-size: 0.8125rem;
  color: #aaa;
}

.entry-rule-wrap code {
  font-size: 0.65rem;
}

#entry-rule-hint {
  font-size: 0.7rem;
  color: #f48771;
}

.field-hint {
  font-size: 0.68rem;
  color: #555;
  font-weight: 400;
  line-height: 1.3;
}

.btn {
  background: #2d2d2d;
  border: 1px solid #444;
  color: #cccccc;
  padding: 0.3rem 0.6rem;
  border-radius: 4px;
  font-size: 0.8125rem;
  cursor: pointer;
}

.btn:hover:not(:disabled) {
  background: #3a3a3a;
  border-color: #555;
}

.btn:disabled {
  opacity: 0.45;
  cursor: not-allowed;
}

.btn-sm {
  padding: 0.2rem 0.45rem;
  font-size: 0.7rem;
}

.btn:focus-visible {
  outline: 2px solid #007acc;
  outline-offset: 2px;
}

.toolbar-sep {
  width: 1px;
  height: 1.25rem;
  background: #3a3a3a;
  flex-shrink: 0;
  align-self: center;
}

.header-links {
  display: flex;
  align-items: center;
  gap: 0.75rem;
  font-size: 0.75rem;
  margin-left: auto;
}

.header-links a {
  color: #6cb6ff;
  text-decoration: none;
}

.header-links a:hover {
  text-decoration: underline;
}

.header-links-sep {
  width: 1px;
  height: 0.9rem;
  background: #3a3a3a;
  flex-shrink: 0;
  align-self: center;
}

.header-tour-btn {
  background: none;
  border: 1px solid #444;
  border-radius: 4px;
  color: #aaa;
  font-size: 0.75rem;
  padding: 0.18rem 0.55rem;
  cursor: pointer;
  line-height: 1;
}

.header-tour-btn:hover {
  color: #ccc;
  border-color: #666;
  background: #2d2d2d;
}

.header-tour-btn:focus-visible {
  outline: 2px solid #007acc;
  outline-offset: 2px;
}

#status {
  font-size: 0.75rem;
  color: #666;
  white-space: nowrap;
  display: flex;
  align-items: center;
  gap: 0.3em;
}

#status::before {
  content: "●";
  font-size: 0.6em;
  flex-shrink: 0;
}

.option-with-help {
  display: flex;
  align-items: center;
  gap: 0.2rem;
}

.option-help {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  width: 0.95rem;
  height: 0.95rem;
  border-radius: 50%;
  border: 1px solid #555;
  color: #888;
  font-size: 0.6rem;
  font-weight: 600;
  line-height: 1;
  text-decoration: none;
  flex-shrink: 0;
}

.option-help:hover {
  color: #ccc;
  border-color: #777;
  background: #333;
}

/* ── Modal overlays (onboarding + download dialog) ── */

#onboarding-modal,
#download-dialog,
#trace-popup {
  position: fixed;
  inset: 0;
  z-index: 200;
  display: flex;
  align-items: center;
  justify-content: center;
  padding: 1rem;
}

#onboarding-modal[hidden],
#download-dialog[hidden],
#trace-popup[hidden] {
  display: none;
}

.modal-backdrop {
  position: absolute;
  inset: 0;
  background: rgba(0, 0, 0, 0.65);
}

.modal-box {
  position: relative;
  background: #2d2d2d;
  border: 1px solid #444;
  border-top: 3px solid #007acc;
  border-radius: 6px;
  padding: 1.5rem;
  width: 100%;
  max-width: 480px;
  box-shadow: 0 8px 32px rgba(0, 0, 0, 0.55);
  animation: modal-in 0.14s ease-out;
}

@keyframes modal-in {
  from { opacity: 0; transform: translateY(-6px); }
  to   { opacity: 1; transform: none; }
}

@media (prefers-reduced-motion: reduce) {
  .modal-box { animation: none; }
}

/* ── Onboarding modal ── */

.onboarding-box h2 {
  margin: 0 0 0.75rem;
  font-size: 1rem;
  font-weight: 600;
  color: #eee;
}

.modal-tagline {
  margin: 0 0 0.5rem;
  font-size: 0.875rem;
  color: #ccc;
  line-height: 1.5;
}

.modal-tagline strong {
  color: #eee;
}

.modal-tagline a {
  color: #6cb6ff;
  text-decoration: none;
}

.modal-tagline a:hover {
  text-decoration: underline;
}

.modal-hint {
  margin: 0 0 1.1rem;
  font-size: 0.8rem;
  color: #999;
  line-height: 1.5;
}

.modal-list {
  margin: 0 0 1.1rem;
  padding-left: 1.1rem;
  color: #b8b8b8;
  font-size: 0.82rem;
  line-height: 1.5;
}

.modal-list li + li {
  margin-top: 0.35rem;
}

.modal-actions {
  display: flex;
  gap: 0.5rem;
  flex-wrap: wrap;
  margin-bottom: 1rem;
}

.btn-primary {
  background: #007acc;
  border-color: #007acc;
  color: #fff;
}

.btn-primary:hover:not(:disabled) {
  background: #1a8fe0;
  border-color: #1a8fe0;
}

.modal-footer {
  display: flex;
  align-items: center;
  justify-content: space-between;
  flex-wrap: wrap;
  gap: 0.5rem;
  border-top: 1px solid #3a3a3a;
  padding-top: 0.75rem;
}

.modal-skip-label {
  display: flex;
  align-items: center;
  gap: 0.35rem;
  font-size: 0.75rem;
  color: #999;
  cursor: pointer;
  user-select: none;
}

.modal-cli-hint {
  font-size: 0.7rem;
  color: #666;
}

.modal-cli-hint code {
  color: #9cdcfe;
}

/* ── Download dialog ── */

.download-box h3 {
  margin: 0 0 0.5rem;
  font-size: 0.9rem;
  font-weight: 600;
  color: #eee;
}

.modal-desc {
  margin: 0 0 1rem;
  font-size: 0.8rem;
  color: #999;
  line-height: 1.5;
}

.modal-desc code {
  color: #9cdcfe;
}

.download-name-row {
  display: flex;
  flex-direction: column;
  gap: 0.3rem;
  margin-bottom: 1rem;
}

.download-name-row label {
  font-size: 0.8rem;
  color: #aaa;
}

.download-name-row input[type="text"] {
  background: #1e1e1e;
  border: 1px solid #555;
  color: #ccc;
  padding: 0.35rem 0.5rem;
  border-radius: 4px;
  font-size: 0.875rem;
  font-family: ui-monospace, monospace;
  width: 100%;
}

.download-name-row input[type="text"]:focus {
  outline: none;
  border-color: #007acc;
}

.download-actions {
  justify-content: flex-end;
  margin-bottom: 0;
}

/* ── Trace markers popup ── */

.trace-popup-box {
  max-width: 400px;
}

.trace-popup-box h3 {
  margin: 0 0 0.6rem;
  font-size: 0.9rem;
  font-weight: 600;
  color: #eee;
}

.trace-keybinds {
  display: grid;
  grid-template-columns: repeat(5, auto);
  gap: 0.4rem 0.75rem;
  margin: 0.75rem 0 1rem;
  width: fit-content;
}

.trace-keybind-row {
  display: flex;
  align-items: center;
  gap: 0.3rem;
  font-size: 0.75rem;
  color: #999;
}

kbd {
  background: #1e1e1e;
  border: 1px solid #555;
  border-radius: 3px;
  padding: 0.1rem 0.35rem;
  font-family: ui-monospace, monospace;
  font-size: 0.7rem;
  color: #ccc;
  white-space: nowrap;
}

.trace-popup-footer {
  display: flex;
  align-items: center;
  gap: 0.6rem;
  flex-wrap: wrap;
  border-top: 1px solid #3a3a3a;
  padding-top: 0.75rem;
}

.modal-link {
  font-size: 0.75rem;
  color: #6cb6ff;
  text-decoration: none;
}

.modal-link:hover {
  text-decoration: underline;
}

/* ── Generated parser pane options bar ── */

.pane-options-bar {
  padding: 0.22rem 0.75rem;
  background: #252526;
  border-bottom: 1px solid #2a2a2a;
  display: flex;
  align-items: center;
  gap: 0.75rem;
  flex-shrink: 0;
}

.pane-options-bar label {
  display: flex;
  align-items: center;
  gap: 0.3rem;
  font-size: 0.75rem;
  color: #888;
  cursor: pointer;
  user-select: none;
}

.pane-options-bar label:hover {
  color: #aaa;
}

/* Allow .option-help to be used as a <button> too */
button.option-help {
  background: none;
  cursor: pointer;
  font-family: inherit;
}

/* ─────────────────────────── */

/* ── Grammar reference panel ── */

#grammar-panel {
  border-top: 1px solid #333;
  background: #1e1e1e;
  flex-shrink: 0;
  font-size: 0.75rem;
  color: #888;
}

#grammar-panel summary {
  padding: 0.4rem 1rem;
  cursor: pointer;
  color: #aaa;
  user-select: none;
}

#grammar-panel summary:hover {
  color: #ccc;
}

.grammar-panel-body {
  padding: 0 1rem 0.6rem;
}

#grammar-pest,
#grammar-peg {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 0.75rem 1.5rem;
  line-height: 1.45;
  padding-top: 0.1rem;
}

#grammar-pest[hidden],
#grammar-peg[hidden] {
  display: none;
}

#grammar-panel h3 {
  margin: 0 0 0.25rem;
  font-size: 0.7rem;
  font-weight: 600;
  text-transform: uppercase;
  letter-spacing: 0.04em;
  color: #4ec9b0;
}

#grammar-panel h3.grammar-not {
  color: #f48771;
}

#grammar-panel ul {
  margin: 0 0 0.3rem;
  padding-left: 1.1rem;
}

#grammar-panel li {
  margin: 0.1rem 0;
}

.grammar-ref-link {
  margin: 0.3rem 0 0;
}

.grammar-ref-link a,
.grammar-output-note a {
  color: #6cb6ff;
  text-decoration: none;
  font-size: 0.7rem;
}

.grammar-ref-link a:hover,
.grammar-output-note a:hover {
  text-decoration: underline;
}

.grammar-output-note {
  margin: 0.35rem 0 0;
  color: #666;
  line-height: 1.45;
}

#tour-bar {
  position: fixed;
  bottom: 1rem;
  left: 50%;
  transform: translateX(-50%);
  z-index: 100;
  background: #2d2d2d;
  border: 1px solid #555;
  border-radius: 4px;
  padding: 0.6rem 0.85rem;
  display: flex;
  align-items: center;
  gap: 0.75rem;
  font-size: 0.8125rem;
  color: #ccc;
  max-width: calc(100vw - 2rem);
}

#tour-bar[hidden] {
  display: none;
}

#tour-bar p {
  margin: 0;
}

#tour-bar .tour-actions {
  display: flex;
  gap: 0.35rem;
  flex-shrink: 0;
}

.tour-highlight {
  box-shadow: 0 0 0 2px #007acc, 0 0 0 5px rgba(0, 122, 204, 0.18);
  border-radius: 4px;
  animation: tour-pulse 1.2s ease-in-out infinite;
}

@keyframes tour-pulse {
  0%, 100% {
    box-shadow: 0 0 0 2px #007acc, 0 0 0 5px rgba(0, 122, 204, 0.18);
  }
  50% {
    box-shadow: 0 0 0 2px #4ec9b0, 0 0 0 6px rgba(78, 201, 176, 0.22);
  }
}

@media (prefers-reduced-motion: reduce) {
  .tour-highlight {
    animation: none;
  }
}

.panes {
  flex: 1;
  display: flex;
  min-height: 0;
}

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

#pane-resizer {
  width: 5px;
  cursor: col-resize;
  background: #333;
  flex-shrink: 0;
  transition: background 0.15s;
}

#pane-resizer:hover,
#pane-resizer.dragging {
  background: #007acc;
}

#pane-resizer:focus-visible {
  outline: none;
  background: #007acc;
}

.pane-header {
  padding: 0.5rem 1rem;
  font-size: 0.75rem;
  font-weight: 600;
  text-transform: uppercase;
  letter-spacing: 0.05em;
  color: #888;
  background: #252526;
  border-bottom: 1px solid #333;
  flex-shrink: 0;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 0.5rem;
}

.pane-header-left {
  display: flex;
  align-items: center;
  gap: 0.5rem;
  min-width: 0;
  overflow: hidden;
}

.pane-actions {
  display: flex;
  align-items: center;
  gap: 0.5rem;
  flex-shrink: 0;
}

#grammar-filename {
  font-size: 0.7rem;
  font-weight: 400;
  text-transform: none;
  letter-spacing: normal;
  color: #6cb6ff;
  overflow: hidden;
  text-overflow: ellipsis;
  white-space: nowrap;
}

.example-description {
  font-size: 0.7rem;
  font-weight: 400;
  text-transform: none;
  letter-spacing: normal;
  color: #888;
  overflow: hidden;
  text-overflow: ellipsis;
  white-space: nowrap;
}

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

.editor-host.drag-over {
  outline: 2px dashed #007acc;
  outline-offset: -2px;
}

.editor-host .cm-editor {
  flex: 1 1 0;
  min-height: 0;
  font-family: ui-monospace, "Cascadia Code", "Fira Code", monospace;
  font-size: 0.875rem;
}

.editor-host .cm-scroller {
  overflow: auto;
}

#error-panel {
  border-top: 1px solid #5a2d2d;
  border-left: 3px solid #f48771;
  background: #2d1f1f;
  flex-shrink: 0;
}

#error-panel:has(#error-list[hidden]) {
  display: none;
}

.error-header {
  padding: 0.35rem 1rem;
  display: flex;
  align-items: center;
  justify-content: space-between;
  border-bottom: 1px solid #5a2d2d;
  font-size: 0.7rem;
  font-weight: 600;
  text-transform: uppercase;
  letter-spacing: 0.05em;
  color: #f48771;
}

#error-list {
  margin: 0;
  padding: 0.5rem 1rem 0.5rem 2rem;
  font-family: ui-monospace, monospace;
  font-size: 0.8125rem;
  color: #f48771;
  max-height: 8rem;
  overflow-y: auto;
}

#error-list li {
  margin: 0.25rem 0;
}

#error-list li[data-jumpable] {
  cursor: pointer;
}

#error-list li[data-jumpable]:hover {
  color: #ff9b87;
}

#error-list li[data-jumpable]:focus-visible {
  outline: 1px solid #f48771;
  outline-offset: 1px;
}

#file-input {
  display: none;
}

/* ── Mobile ── */
@media (max-width: 768px) {
  .header-brand {
    flex-direction: column;
    align-items: flex-start;
  }

  .header-links {
    margin-left: 0;
  }

  #grammar-pest,
  #grammar-peg {
    grid-template-columns: 1fr;
  }

  .panes {
    flex-direction: column;
  }

  #pane-resizer {
    display: none;
  }

  .pane {
    border-left: none !important;
    border-top: 1px solid #333;
  }

  #grammar-pane {
    flex: 0 0 min(40%, 12rem) !important;
    border-top: none;
  }

  #rust-pane {
    flex: 1 1 0 !important;
  }

}

/* Increase touch targets on coarse-pointer devices (mobile/tablet) */
@media (max-width: 768px) and (pointer: coarse) {
  .btn-sm {
    padding: 0.35rem 0.6rem;
    font-size: 0.75rem;
  }

  .mode-btn {
    padding: 0.4rem 0.9rem;
  }
}