:root {
  --bg:           #f8f8f8;
  --bg-raised:    #ffffff;
  --bg-active:    #ebebeb;
  --border:       #e0e0e0;
  --border-sub:   #e8e8e8;
  --border-hover: #999;
  --text:         #1e1e1e;
  --text-dim:     #555;
  --text-dimmer:  #888;
  --text-btn:     #555;
  --text-btn-hover: #111;
  --text-strong:  #222;
  --error:        #c0392b;
  --shadow-active: rgba(0,0,0,0.12);
}

[data-theme="dark"] {
  --bg:           #1a1a1a;
  --bg-raised:    #111;
  --bg-active:    #2a2a2a;
  --border:       #333;
  --border-sub:   #222;
  --border-hover: #555;
  --text:         #d4d4d4;
  --text-dim:     #666;
  --text-dimmer:  #888;
  --text-btn:     #888;
  --text-btn-hover: #ccc;
  --text-strong:  #ccc;
  --error:        #f48771;
  --shadow-active: rgba(0,0,0,0.6);
}

* { box-sizing: border-box; margin: 0; padding: 0; }

body {
  font-family: monospace;
  background: var(--bg);
  color: var(--text);
  height: 100vh;
  display: flex;
  flex-direction: column;
}

header {
  padding: 0.75rem 1.25rem;
  background: var(--bg-raised);
  border-bottom: 1px solid var(--border);
  font-size: 0.85rem;
  color: var(--text-dimmer);
  display: flex;
  align-items: center;
  justify-content: space-between;
}

header strong { color: var(--text-strong); }

.header-left {
  display: flex;
  align-items: center;
  gap: 1rem;
}

.menubar {
  display: flex;
  align-items: center;
  gap: 0.1rem;
}

.menu {
  position: relative;
}

.menu-trigger {
  font-family: monospace;
  font-size: 0.85rem;
  color: var(--text-btn);
  background: none;
  border: none;
  padding: 0.2rem 0.5rem;
  cursor: pointer;
  border-radius: 2px;
}

a.menu-trigger {
  text-decoration: none;
  display: inline-block;
}

.menu-trigger:hover,
.menu-trigger.open {
  color: var(--text-btn-hover);
  background: var(--bg-active);
}

.menu-dropdown {
  display: none;
  position: absolute;
  top: 100%;
  left: 0;
  z-index: 100;
  background: var(--bg-raised);
  border: 1px solid var(--border);
  box-shadow: 0 4px 12px var(--shadow-active);
  min-width: 130px;
  list-style: none;
  padding: 0.25rem 0;
  margin-top: 2px;
}

.menu-dropdown.open {
  display: block;
}

.menu-dropdown li button {
  display: block;
  width: 100%;
  text-align: left;
  font-family: monospace;
  font-size: 0.85rem;
  color: var(--text-btn);
  background: none;
  border: none;
  padding: 0.3rem 1rem;
  cursor: pointer;
}

.menu-dropdown li button:hover {
  color: var(--text-btn-hover);
  background: var(--bg-active);
}

.menu-sub {
  position: relative;
}

.menu-submenu {
  display: none;
  position: absolute;
  left: 100%;
  top: -0.25rem;
  z-index: 101;
  background: var(--bg-raised);
  border: 1px solid var(--border);
  box-shadow: 0 4px 12px var(--shadow-active);
  min-width: 110px;
  list-style: none;
  padding: 0.25rem 0;
}

.menu-submenu.open {
  display: block;
}

.menu-submenu li button {
  display: block;
  width: 100%;
  text-align: left;
  font-family: monospace;
  font-size: 0.85rem;
  color: var(--text-btn);
  background: none;
  border: none;
  padding: 0.3rem 1rem;
  cursor: pointer;
}

.menu-submenu li button:hover:not(:disabled) {
  color: var(--text-btn-hover);
  background: var(--bg-active);
}

.menu-submenu li button:disabled {
  color: var(--text-dimmer);
  cursor: default;
  opacity: 0.5;
}

.menu-separator {
  height: 1px;
  background: var(--border-sub);
  margin: 0.25rem 0;
}

#btn-theme {
  font-size: 1rem;
  color: var(--text-dimmer);
  background: none;
  border: none;
  padding: 0;
  cursor: pointer;
  line-height: 1;
}

#btn-theme:hover {
  color: var(--text-strong);
}

.panes {
  flex: 1;
  display: grid;
  grid-template-columns: 1fr 1fr;
  overflow: hidden;
}

.pane {
  display: flex;
  flex-direction: column;
  overflow: hidden;
}

.pane + .pane {
  border-left: 1px solid var(--border);
}

#editor {
  flex: 1;
  overflow: auto;
  min-height: 0;
}

#editor .cm-editor {
  height: 100%;
  font-size: 0.9rem;
}

#editor .cm-scroller {
  font-family: monospace;
  line-height: 1.6;
}

#right {
  display: flex;
  flex-direction: column;
  overflow: hidden;
}

#viewer-pane {
  flex: 1;
  overflow: hidden;
  position: relative;
}

/* render.mjs mounts into .viewport — override its 100vh to fill our container */
#viewer-pane .viewport {
  position: absolute;
  inset: 0;
}

#console-pane {
  border-top: 1px solid var(--border);
  background: var(--bg-raised);
  flex-shrink: 0;
  max-height: 30vh;
  overflow: auto;
  display: flex;
  flex-direction: column;
}

.console-header {
  padding: 0.3rem 1rem;
  font-size: 0.75rem;
  color: var(--text-dim);
  border-bottom: 1px solid var(--border-sub);
  flex-shrink: 0;
}

pre {
  padding: 0 1rem 0.75rem;
  font-size: 0.85rem;
  line-height: 1.6;
  white-space: pre;
}

pre.error { color: var(--error); }

#editor-footer {
  display: flex;
  align-items: center;
  justify-content: flex-end;
  gap: 0.4rem;
  padding: 0.4rem 1rem;
  font-size: 0.75rem;
  background: var(--bg-raised);
  border-top: 1px solid var(--border-sub);
  flex-shrink: 0;
}

#editor-footer button {
  font-family: monospace;
  font-size: 0.75rem;
  color: var(--text-btn);
  background: none;
  border: 1px solid var(--border);
  padding: 0.15rem 0.5rem;
  cursor: pointer;
  border-radius: 2px;
}

#editor-footer button:hover {
  color: var(--text-btn-hover);
  border-color: var(--border-hover);
}

#view-mode-controls {
  display: flex;
  align-items: center;
  gap: 0.4rem;
  border-right: 1px solid var(--border);
  padding-right: 0.6rem;
  margin-right: 0.2rem;
}

#editor-footer button:disabled {
  color: var(--text-dimmer);
  border-color: var(--border-sub);
  cursor: default;
  opacity: 0.5;
}

#run-controls {
  display: flex;
  align-items: center;
  gap: 0.4rem;
  border-right: 1px solid var(--border);
  padding-right: 0.6rem;
  margin-right: 0.2rem;
}

#editor-footer button.active {
  color: var(--text-btn-hover);
  border-color: var(--border-hover);
  background: var(--bg-active);
  box-shadow: inset 0 1px 3px var(--shadow-active);
}

#tab-bar {
  display: none;
  align-items: stretch;
  background: var(--bg);
  border-bottom: 1px solid var(--border);
  overflow-x: auto;
  flex-shrink: 0;
  font-family: monospace;
  font-size: 0.75rem;
}

.tab {
  display: flex;
  align-items: center;
  gap: 0.3rem;
  padding: 0.4rem 0.6rem 0.4rem 1rem;
  border-right: 1px solid var(--border);
  cursor: default;
  color: var(--text-dim);
  white-space: nowrap;
  min-width: 0;
  user-select: none;
}

.tab:hover { background: var(--bg-active); color: var(--text); }

.tab.active {
  background: var(--bg-raised);
  color: var(--text);
  box-shadow: inset 0 2px 0 var(--border-hover);
}

.tab-label {
  max-width: 140px;
  overflow: hidden;
  text-overflow: ellipsis;
  cursor: pointer;
}

.tab-close {
  font-family: monospace;
  font-size: 0.9rem;
  color: var(--text-dimmer);
  background: none;
  border: none;
  cursor: pointer;
  padding: 0 2px;
  line-height: 1;
  flex-shrink: 0;
}

.tab-close:hover { color: var(--text); }

#rename-dialog-overlay {
  display: none;
  position: fixed;
  inset: 0;
  z-index: 200;
  background: rgba(0,0,0,0.35);
  align-items: center;
  justify-content: center;
}

#rename-dialog-overlay.open { display: flex; }

#rename-dialog {
  background: var(--bg-raised);
  border: 1px solid var(--border);
  box-shadow: 0 8px 24px var(--shadow-active);
  padding: 1.25rem 1.5rem;
  width: 320px;
  max-width: 90vw;
  font-family: monospace;
  font-size: 0.85rem;
}

#rename-dialog label {
  display: block;
  color: var(--text-dim);
  margin-bottom: 0.5rem;
}

#rename-dialog input[type="text"] {
  display: block;
  width: 100%;
  font-family: monospace;
  font-size: 0.85rem;
  color: var(--text);
  background: var(--bg);
  border: 1px solid var(--border);
  padding: 0.35rem 0.6rem;
  outline: none;
  box-sizing: border-box;
}

#rename-dialog input[type="text"]:focus { border-color: var(--border-hover); }

#rename-dialog-error {
  color: var(--error);
  font-size: 0.8rem;
  min-height: 1.2em;
  margin-top: 0.4rem;
}

#rename-dialog-actions {
  display: flex;
  justify-content: flex-end;
  gap: 0.5rem;
  margin-top: 1rem;
}

#rename-dialog-actions button {
  font-family: monospace;
  font-size: 0.8rem;
  color: var(--text-btn);
  background: none;
  border: 1px solid var(--border);
  padding: 0.2rem 0.75rem;
  cursor: pointer;
  border-radius: 2px;
}

#rename-dialog-actions button:hover {
  color: var(--text-btn-hover);
  border-color: var(--border-hover);
}

#help-dialog-overlay {
  display: none;
  position: fixed;
  inset: 0;
  z-index: 200;
  background: rgba(0,0,0,0.35);
  align-items: center;
  justify-content: center;
}

#help-dialog-overlay.open { display: flex; }

#help-dialog {
  background: var(--bg-raised);
  border: 1px solid var(--border);
  box-shadow: 0 8px 24px var(--shadow-active);
  width: 816px;
  max-width: 92vw;
  max-height: 82vh;
  display: flex;
  flex-direction: column;
  font-family: monospace;
  font-size: 0.85rem;
}

#help-dialog-header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 0.9rem 1.25rem 0.75rem;
  border-bottom: 1px solid var(--border);
  flex-shrink: 0;
}

#help-dialog-header h2 {
  font-size: 1rem;
  font-weight: bold;
  color: var(--text-strong);
  letter-spacing: 0.05em;
}

#help-dialog-close {
  font-family: monospace;
  font-size: 1.1rem;
  color: var(--text-dimmer);
  background: none;
  border: none;
  cursor: pointer;
  padding: 0 2px;
  line-height: 1;
}

#help-dialog-close:hover { color: var(--text); }

#help-dialog-body {
  overflow-y: auto;
  padding: 1rem 1.25rem 1.25rem;
}

.help-intro {
  color: var(--text-dim);
  line-height: 1.6;
  margin-bottom: 1.25rem;
}

.help-section {
  margin-bottom: 1.25rem;
}

.help-section h3 {
  font-size: 0.75rem;
  text-transform: uppercase;
  letter-spacing: 0.08em;
  color: var(--text-dimmer);
  margin-bottom: 0.5rem;
  padding-bottom: 0.25rem;
  border-bottom: 1px solid var(--border-sub);
}

.help-table {
  width: 100%;
  border-collapse: collapse;
}

.help-table tr + tr td { border-top: 1px solid var(--border-sub); }

.help-table td {
  padding: 0.3rem 0.5rem;
  vertical-align: top;
  line-height: 1.5;
}

.help-table td:first-child {
  color: var(--text-strong);
  white-space: nowrap;
  padding-right: 1.5rem;
  width: 1%;
}

.help-table td:last-child {
  color: var(--text-dim);
}

#new-dialog-overlay {
  display: none;
  position: fixed;
  inset: 0;
  z-index: 200;
  background: rgba(0,0,0,0.35);
  align-items: center;
  justify-content: center;
}

#new-dialog-overlay.open { display: flex; }

#new-dialog {
  background: var(--bg-raised);
  border: 1px solid var(--border);
  box-shadow: 0 8px 24px var(--shadow-active);
  padding: 1.25rem 1.5rem;
  font-family: monospace;
  font-size: 0.85rem;
}

#new-dialog p {
  color: var(--text-dim);
  margin-bottom: 1rem;
}

#new-dialog-actions {
  display: flex;
  justify-content: flex-end;
  gap: 0.5rem;
}

#new-dialog-actions button {
  font-family: monospace;
  font-size: 0.8rem;
  color: var(--text-btn);
  background: none;
  border: 1px solid var(--border);
  padding: 0.2rem 0.75rem;
  cursor: pointer;
  border-radius: 2px;
}

#new-dialog-actions button:hover {
  color: var(--text-btn-hover);
  border-color: var(--border-hover);
}

#load-dialog-overlay {
  display: none;
  position: fixed;
  inset: 0;
  z-index: 200;
  background: rgba(0,0,0,0.35);
  align-items: center;
  justify-content: center;
}

#load-dialog-overlay.open {
  display: flex;
}

#load-dialog {
  background: var(--bg-raised);
  border: 1px solid var(--border);
  box-shadow: 0 8px 24px var(--shadow-active);
  padding: 1.25rem 1.5rem;
  width: 480px;
  max-width: 90vw;
  font-family: monospace;
  font-size: 0.85rem;
}

#load-dialog label {
  display: block;
  color: var(--text-dim);
  margin-bottom: 0.5rem;
}

#load-dialog input[type="url"] {
  display: block;
  width: 100%;
  font-family: monospace;
  font-size: 0.85rem;
  color: var(--text);
  background: var(--bg);
  border: 1px solid var(--border);
  padding: 0.35rem 0.6rem;
  outline: none;
  box-sizing: border-box;
}

#load-dialog input[type="url"]:focus {
  border-color: var(--border-hover);
}

#load-dialog-error {
  color: var(--error);
  font-size: 0.8rem;
  min-height: 1.2em;
  margin-top: 0.4rem;
}

#load-dialog-actions {
  display: flex;
  justify-content: flex-end;
  gap: 0.5rem;
  margin-top: 1rem;
}

#load-dialog-actions button {
  font-family: monospace;
  font-size: 0.8rem;
  color: var(--text-btn);
  background: none;
  border: 1px solid var(--border);
  padding: 0.2rem 0.75rem;
  cursor: pointer;
  border-radius: 2px;
}

#load-dialog-actions button:hover {
  color: var(--text-btn-hover);
  border-color: var(--border-hover);
}

#load-dialog-actions button#load-dialog-confirm {
  color: var(--text-strong);
  border-color: var(--border-hover);
}

/* Layout tab bar — hidden on wide screens */
#layout-tab-bar {
  display: none;
  flex-shrink: 0;
  border-bottom: 1px solid var(--border);
  background: var(--bg-raised);
}

#layout-tab-bar button {
  flex: 1;
  padding: 0.6rem 1rem;
  border: none;
  background: transparent;
  color: var(--text-btn);
  font-size: 0.9rem;
  cursor: pointer;
  border-bottom: 2px solid transparent;
}

#layout-tab-bar button.active {
  color: var(--text-strong);
  border-bottom-color: var(--text-strong);
}

#layout-tab-bar button:hover {
  color: var(--text-btn-hover);
}

@media (max-width: 768px) {
  #layout-tab-bar {
    display: flex;
  }

  .panes {
    grid-template-columns: 1fr;
  }

  .panes[data-active-pane="editor"] #right {
    display: none;
  }

  .panes[data-active-pane="viewer"] > .pane:first-child {
    display: none;
  }

  .pane + .pane {
    border-left: none;
  }
}