:root {
  --bg: #120e18;
  --panel: #1b1624;
  --panel-2: #231c2f;
  --panel-3: #2c2439;
  --border: #342a45;
  --text: #ece6f5;
  --muted: #a397b8;
  --faint: #6f6485;
  --accent: #ffb454;
  --accent-ink: #1c140a;
  --good: #6cd06a;
  --bad: #ff5c7a;
  --info: #7cc7ff;
  --code-bg: #15111c;
  --mono: ui-monospace, "SF Mono", "JetBrains Mono", Menlo, Consolas, "Liberation Mono", monospace;
  --sans: system-ui, -apple-system, "Segoe UI", Roboto, "Helvetica Neue", sans-serif;
  --guide-width: 40%;
  --run-height: 45%;
  --game-width: 60%;
  color-scheme: dark;
}

* {
  box-sizing: border-box;
}

html,
body {
  margin: 0;
  height: 100%;
  background: var(--bg);
  color: var(--text);
  font-family: var(--sans);
  font-size: 15px;
}

body.loading #app {
  opacity: 0.4;
}

body.dragging {
  user-select: none;
}

body.dragging-col {
  cursor: col-resize;
}

body.dragging-row {
  cursor: row-resize;
}

body.dragging iframe {
  pointer-events: none;
}

button {
  font: inherit;
  color: inherit;
  cursor: pointer;
}

button:disabled {
  cursor: default;
}

code,
kbd,
pre {
  font-family: var(--mono);
}

#app {
  display: grid;
  grid-template-columns: var(--guide-width) 6px 1fr;
  /* Rows must be capped at the viewport, or panes grow instead of scrolling. */
  grid-template-rows: minmax(0, 1fr);
  height: 100vh;
  overflow: hidden;
}

/* ------------------------------------------------------------ splitters */

.splitter {
  touch-action: none;
  background: var(--bg);
  position: relative;
  z-index: 2;
}

.splitter:hover,
.splitter:active {
  background: var(--accent);
}

.splitter-v {
  cursor: col-resize;
  width: 6px;
}

.splitter-h {
  cursor: row-resize;
  height: 6px;
  flex: none;
}

/* ------------------------------------------------------------ buttons */

.primary,
.secondary,
.small,
.play {
  border-radius: 8px;
  border: 1px solid var(--border);
  padding: 8px 16px;
  font-weight: 600;
  transition: background 0.15s, transform 0.05s, opacity 0.15s;
}

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

.primary:not(:disabled):hover {
  background: #ffc57a;
}

.primary:disabled {
  background: var(--panel-3);
  border-color: var(--border);
  color: var(--faint);
}

.primary:not(:disabled):active,
.secondary:not(:disabled):active,
.play:not(:disabled):active {
  transform: translateY(1px);
}

.secondary,
.small {
  background: var(--panel-2);
}

.secondary:not(:disabled):hover,
.small:hover {
  background: var(--panel-3);
}

.secondary:disabled {
  opacity: 0.4;
}

.small {
  padding: 4px 10px;
  font-size: 12.5px;
  border-radius: 6px;
}

.icon {
  background: none;
  border: 0;
  color: var(--muted);
  padding: 2px 6px;
  border-radius: 4px;
  font-size: 14px;
}

.icon:hover {
  color: var(--text);
  background: var(--panel-3);
}

.link {
  background: none;
  border: 0;
  padding: 0;
  color: var(--info);
  text-decoration: underline;
  font-weight: 600;
}

/* ------------------------------------------------------------ guide */

#guide {
  display: flex;
  flex-direction: column;
  min-width: 0;
  min-height: 0;
  background: var(--panel);
  position: relative;
}

.guide-header {
  display: flex;
  align-items: center;
  gap: 14px;
  padding: 12px 18px;
  border-bottom: 1px solid var(--border);
}

.menu-button {
  background: var(--panel-2);
  border: 1px solid var(--border);
  border-radius: 8px;
  padding: 7px 12px;
  font-weight: 600;
  font-size: 13.5px;
  white-space: nowrap;
}

.menu-button:hover {
  background: var(--panel-3);
}

.guide-titles {
  flex: 1;
  min-width: 0;
}

.eyebrow {
  color: var(--accent);
  font-size: 11.5px;
  font-weight: 700;
  letter-spacing: 0.08em;
  text-transform: uppercase;
}

.guide-title {
  font-size: 17px;
  font-weight: 700;
  white-space: nowrap;
  overflow: hidden;
  text-overflow: ellipsis;
}

.guide-mascot {
  width: 40px;
  height: 40px;
  image-rendering: pixelated;
  animation: bob 1.6s ease-in-out infinite;
}

@keyframes bob {
  50% {
    transform: translateY(-3px);
  }
}

.step-dots {
  display: flex;
  flex-wrap: wrap;
  gap: 5px;
  padding: 10px 18px;
  border-bottom: 1px solid var(--border);
  min-height: 12px;
}

.step-dots:empty {
  display: none;
}

.dot {
  width: 22px;
  height: 7px;
  border-radius: 4px;
  border: 0;
  padding: 0;
  background: var(--panel-3);
}

.dot:not(:disabled):hover {
  background: var(--faint);
}

.dot-done {
  background: #4d8f4c;
}

.dot-current {
  background: var(--accent);
}

.chapter-menu {
  position: absolute;
  top: 62px;
  left: 14px;
  right: 14px;
  max-height: calc(100% - 80px);
  overflow: auto;
  z-index: 20;
  background: var(--panel-2);
  border: 1px solid var(--border);
  border-radius: 12px;
  box-shadow: 0 18px 50px rgba(0, 0, 0, 0.55);
  padding: 8px;
}

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

.chapter-list button {
  display: flex;
  align-items: center;
  gap: 12px;
  width: 100%;
  text-align: left;
  background: none;
  border: 0;
  border-radius: 8px;
  padding: 8px 10px;
}

.chapter-list button:hover {
  background: var(--panel-3);
}

.chapter-list li.current button {
  background: rgba(255, 180, 84, 0.12);
}

.chapter-list b {
  display: block;
  font-size: 14px;
}

.chapter-list small {
  display: block;
  color: var(--muted);
  font-size: 12.5px;
}

.chapter-check {
  flex: none;
  width: 28px;
  height: 28px;
  border-radius: 50%;
  display: grid;
  place-items: center;
  background: var(--panel-3);
  font-weight: 700;
  font-size: 13px;
}

.chapter-list li.current .chapter-check {
  background: var(--accent);
  color: var(--accent-ink);
}

.menu-actions {
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
  padding: 10px 10px 4px;
  margin-top: 6px;
  border-top: 1px solid var(--border);
}

.menu-actions button {
  background: var(--panel);
  border: 1px solid var(--border);
  border-radius: 8px;
  padding: 7px 12px;
  font-size: 13px;
  font-weight: 600;
}

.menu-actions button:hover {
  background: var(--panel-3);
}

.menu-actions .danger {
  color: #ffa0b2;
}

.guide-scroll {
  flex: 1;
  min-height: 0;
  overflow-y: auto;
  padding: 8px 26px 30px;
}

.step-content {
  max-width: 720px;
  line-height: 1.65;
  font-size: 15.5px;
}

.step-content h1,
.step-content h2 {
  line-height: 1.25;
}

.step-content h2 {
  font-size: 24px;
  margin: 4px 0 14px;
}

.step-content h3 {
  font-size: 17px;
  margin: 26px 0 8px;
  color: var(--accent);
}

.step-label {
  margin-top: 16px;
  color: var(--muted);
  font-size: 12.5px;
  font-weight: 700;
  letter-spacing: 0.06em;
  text-transform: uppercase;
}

.chapter-intro {
  padding: 26px 0 8px;
}

.chapter-number {
  color: var(--accent);
  font-weight: 800;
  letter-spacing: 0.1em;
  text-transform: uppercase;
  font-size: 13px;
}

.chapter-intro h1 {
  font-size: 34px;
  margin: 6px 0 6px;
}

.chapter-subtitle {
  font-size: 18px;
  color: var(--muted);
  margin: 0;
}

.chapter-time {
  color: var(--faint);
  font-size: 13.5px;
  margin: 8px 0 0;
}

.step-content p,
.step-content ul,
.step-content ol {
  margin: 0 0 14px;
}

.step-content li {
  margin-bottom: 6px;
}

.step-content a {
  color: var(--info);
}

.step-content :not(pre) > code {
  background: var(--panel-3);
  border: 1px solid var(--border);
  padding: 0.05em 0.35em;
  border-radius: 5px;
  font-size: 0.9em;
  white-space: nowrap;
}

kbd {
  display: inline-block;
  padding: 0 0.45em;
  border: 1px solid var(--border);
  border-bottom-width: 3px;
  border-radius: 5px;
  background: var(--panel-2);
  font-size: 0.85em;
  line-height: 1.5;
}

pre.code {
  background: var(--code-bg);
  border: 1px solid var(--border);
  border-radius: 10px;
  padding: 12px 14px;
  margin: 0 0 14px;
  overflow-x: auto;
  font-size: 13.5px;
  line-height: 1.55;
  tab-size: 2;
}

/* A step's instructions for what to type */
.op {
  border-left: 3px solid var(--accent);
  padding: 2px 0 2px 16px;
  margin: 18px 0 20px;
}

.op-where {
  margin: 0 0 8px !important;
  color: var(--text);
}

.op .filename {
  color: var(--accent);
  font-family: var(--mono);
  font-weight: 600;
}

.op .legend {
  color: var(--muted);
  font-size: 13px;
}

.show-me {
  background: none;
  border: 1px solid var(--border);
  color: var(--muted);
  border-radius: 999px;
  padding: 1px 10px;
  font-size: 12px;
  margin-left: 4px;
  vertical-align: 1px;
}

.show-me:hover {
  color: var(--text);
  border-color: var(--muted);
}

pre.code.anchor {
  opacity: 0.8;
  border-style: dashed;
}

pre.code.type-this {
  position: relative;
  border-color: rgba(255, 180, 84, 0.45);
  box-shadow: 0 0 0 3px rgba(255, 180, 84, 0.07);
  user-select: none;
  -webkit-user-select: none;
  padding-top: 26px;
}

pre.code.type-this::before {
  content: "TYPE THIS";
  position: absolute;
  top: 7px;
  right: 12px;
  color: var(--accent);
  font: 700 10px var(--sans);
  letter-spacing: 0.12em;
  opacity: 0.8;
}

.line-added {
  display: inline-block;
  min-width: 100%;
  background: rgba(108, 208, 106, 0.14);
  box-shadow: -14px 0 0 rgba(108, 208, 106, 0.14), 14px 0 0 rgba(108, 208, 106, 0.14);
}

.line-removed {
  display: inline-block;
  min-width: 100%;
  background: rgba(255, 92, 122, 0.14);
  text-decoration: line-through;
  text-decoration-color: rgba(255, 92, 122, 0.6);
}

.callout {
  border-radius: 10px;
  padding: 12px 16px 2px;
  margin: 0 0 16px;
  background: var(--panel-2);
  border: 1px solid var(--border);
  border-left: 4px solid var(--info);
}

.callout p:last-child {
  margin-bottom: 10px;
}

.callout pre.code {
  margin-bottom: 10px;
}

.callout-tip {
  border-left-color: var(--good);
}

.callout-try-it {
  border-left-color: var(--accent);
  background: rgba(255, 180, 84, 0.06);
}

.callout-heads-up {
  border-left-color: var(--bad);
}

.callout-new-word,
.callout-concept {
  border-left-color: #c89bff;
}

.callout-fun-fact,
.callout-why {
  border-left-color: var(--info);
}

.callout-challenge {
  border-left-color: #ffd23f;
}

.callout-fresh {
  border-left-color: var(--faint);
  font-size: 14px;
  color: var(--muted);
}

.guide-footer {
  border-top: 1px solid var(--border);
  padding: 12px 18px 14px;
  background: var(--panel);
}

.status {
  font-size: 14px;
  line-height: 1.5;
  margin-bottom: 10px;
  padding: 10px 12px;
  border-radius: 8px;
  background: var(--panel-2);
  max-height: 45vh;
  overflow: auto;
}

.status-ok {
  background: rgba(108, 208, 106, 0.12);
  color: #b9f0b3;
}

.status-error {
  background: rgba(255, 92, 122, 0.1);
  color: #ffc2cd;
}

.hint {
  margin-top: 10px;
  padding-top: 10px;
  border-top: 1px solid var(--border);
}

.hint p {
  margin: 0 0 6px;
}

.hint pre.code {
  margin-bottom: 8px;
  font-size: 13px;
  padding: 8px 10px;
}

.hint-tips {
  color: var(--muted);
  font-size: 13px;
}

.hint-actions {
  display: flex;
  gap: 8px;
  margin-top: 8px;
}

.guide-buttons {
  display: flex;
  gap: 8px;
}

.guide-buttons #next-button {
  margin-left: auto;
  min-width: 130px;
}

/* ------------------------------------------------------------ workbench */

.workbench {
  display: grid;
  grid-template-columns: 190px 1fr;
  grid-template-rows: minmax(0, 1fr);
  min-width: 0;
  min-height: 0;
  background: var(--code-bg);
}

.files {
  background: var(--panel);
  border-right: 1px solid var(--border);
  display: flex;
  flex-direction: column;
  min-height: 0;
}

.files-header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 10px 10px 8px 14px;
  font-size: 12px;
  font-weight: 700;
  letter-spacing: 0.08em;
  text-transform: uppercase;
  color: var(--muted);
  border-bottom: 1px solid var(--border);
  height: 42px;
}

.files-header .small {
  text-transform: none;
  letter-spacing: 0;
  font-size: 12px;
  color: var(--text);
}

.file-list {
  flex: 1;
  min-height: 0;
  overflow-y: auto;
  padding: 6px 0 20px;
}

.file-group {
  font-size: 11px;
  font-weight: 700;
  letter-spacing: 0.06em;
  text-transform: uppercase;
  color: var(--faint);
  padding: 12px 14px 4px;
}

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

.file-list li {
  display: flex;
  align-items: center;
}

.file-list li.active {
  background: rgba(255, 180, 84, 0.12);
}

.file-item {
  flex: 1;
  display: flex;
  align-items: center;
  gap: 8px;
  min-width: 0;
  background: none;
  border: 0;
  text-align: left;
  padding: 4px 8px 4px 16px;
  font-size: 13px;
  font-family: var(--mono);
  white-space: nowrap;
  overflow: hidden;
  text-overflow: ellipsis;
}

.file-item:hover {
  background: var(--panel-2);
}

.file-icon {
  width: 16px;
  flex: none;
  text-align: center;
  font-size: 12px;
}

.file-icon img {
  width: 16px;
  height: 16px;
  image-rendering: pixelated;
  vertical-align: middle;
}

.file-delete {
  background: none;
  border: 0;
  color: var(--faint);
  padding: 0 10px;
  visibility: hidden;
}

.file-list li:hover .file-delete {
  visibility: visible;
}

.file-delete:hover {
  color: var(--bad);
}

.new-file-form {
  padding: 6px 10px;
}

.new-file-form input {
  width: 100%;
  background: var(--code-bg);
  border: 1px solid var(--accent);
  border-radius: 6px;
  color: var(--text);
  font: 13px var(--mono);
  padding: 5px 8px;
  outline: none;
}

.new-file-error {
  color: var(--bad);
  font-size: 12px;
  margin-top: 4px;
}

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

.toolbar {
  display: flex;
  align-items: stretch;
  height: 42px;
  flex: none;
  background: var(--panel);
  border-bottom: 1px solid var(--border);
}

.tabs {
  display: flex;
  flex: 1;
  min-width: 0;
  overflow-x: auto;
  scrollbar-width: thin;
}

.tab {
  display: flex;
  align-items: center;
  border-right: 1px solid var(--border);
  color: var(--muted);
  flex: none;
}

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

.tab-solution .tab-label {
  color: #b9f0b3;
}

.tab-label {
  background: none;
  border: 0;
  padding: 0 4px 0 14px;
  height: 100%;
  font: 13px var(--mono);
}

.tab-close {
  background: none;
  border: 0;
  color: var(--faint);
  padding: 0 10px 0 6px;
  height: 100%;
}

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

.toolbar-buttons {
  display: flex;
  align-items: center;
  padding: 0 10px;
  gap: 8px;
}

.play {
  background: var(--good);
  border-color: var(--good);
  color: #0f2410;
  padding: 6px 18px;
}

.play:not(:disabled):hover {
  background: #86e284;
}

.play:disabled {
  opacity: 0.7;
}

.editor-area {
  flex: 1;
  min-height: 0;
  position: relative;
}

.editor-host,
.asset-preview {
  position: absolute;
  inset: 0;
}

.editor-host[hidden],
.asset-preview[hidden] {
  display: none;
}

.run-area {
  height: var(--run-height);
  flex: none;
  display: flex;
  min-height: 0;
  background: var(--panel);
}

.workbench:not(.show-run) #split-run,
.workbench:not(.show-run) .run-area {
  display: none;
}

.workbench.max-game .editor-area,
.workbench.max-game #split-run {
  display: none;
}

.workbench.max-game .run-area {
  flex: 1;
  height: auto;
}

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

.game-pane {
  width: var(--game-width);
  flex: none;
}

.console-pane {
  flex: 1;
}

.pane-header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 4px 8px 4px 14px;
  height: 32px;
  flex: none;
  font-size: 11.5px;
  font-weight: 700;
  letter-spacing: 0.08em;
  text-transform: uppercase;
  color: var(--muted);
  border-bottom: 1px solid var(--border);
}

.game-host {
  flex: 1;
  min-height: 0;
  background: #0c0911;
  position: relative;
}

.game-frame {
  width: 100%;
  height: 100%;
  border: 0;
  display: block;
}

.game-placeholder {
  position: absolute;
  inset: 0;
  display: grid;
  place-items: center;
  color: var(--faint);
  font-size: 14px;
}

.console-output {
  flex: 1;
  overflow-y: auto;
  font: 13px/1.5 var(--mono);
  padding: 6px 0;
  background: var(--code-bg);
}

.console-line {
  padding: 3px 12px;
  border-bottom: 1px solid rgba(52, 42, 69, 0.5);
  white-space: pre-wrap;
  word-break: break-word;
}

.console-info {
  color: var(--muted);
}

.console-warn {
  color: #ffd580;
  background: rgba(255, 213, 128, 0.06);
}

.console-error {
  color: #ffb3c1;
  background: rgba(255, 92, 122, 0.08);
  font-family: var(--sans);
}

.console-original {
  color: var(--faint);
  font: 12px var(--mono);
  margin-top: 2px;
}

.console-link {
  background: rgba(255, 92, 122, 0.18);
  border: 0;
  border-radius: 4px;
  color: #ffd1da;
  font: 600 12px var(--mono);
  padding: 1px 6px;
  margin-right: 4px;
}

.console-link:hover {
  background: rgba(255, 92, 122, 0.32);
}

/* ------------------------------------------------------------ editor */

.editor {
  display: flex;
  height: 100%;
  background: var(--code-bg);
  font: 14px/21px var(--mono);
  tab-size: 2;
}

.editor-gutter {
  width: 50px;
  flex: none;
  overflow: hidden;
  position: relative;
  color: var(--faint);
  text-align: right;
  user-select: none;
  border-right: 1px solid rgba(52, 42, 69, 0.6);
}

.editor-gutter-inner {
  padding: 12px 10px 0 0;
  will-change: transform;
}

.gutter-line {
  height: 21px;
}

.gutter-error {
  color: #fff;
  background: var(--bad);
  border-radius: 0 10px 10px 0;
  margin-right: -10px;
  padding-right: 10px;
  cursor: help;
}

.editor-code {
  position: relative;
  flex: 1;
  min-width: 0;
  overflow: hidden;
}

.editor-highlight,
.editor-input {
  margin: 0;
  padding: 12px 16px 40px;
  font: inherit;
  line-height: inherit;
  white-space: pre;
  tab-size: 2;
  letter-spacing: 0;
}

.editor-highlight {
  position: absolute;
  top: 0;
  left: 0;
  min-width: 100%;
  pointer-events: none;
  color: var(--text);
  will-change: transform;
}

.editor-highlight .line {
  min-height: 21px;
  margin: 0 -16px;
  padding: 0 16px;
}

.line-error {
  background: rgba(255, 92, 122, 0.13);
}

.line-target {
  background: rgba(255, 180, 84, 0.16);
  box-shadow: inset 3px 0 0 var(--accent);
  animation: target-pulse 1.4s ease-in-out 2;
}

@keyframes target-pulse {
  50% {
    background: rgba(255, 180, 84, 0.34);
  }
}

.editor-input {
  position: absolute;
  inset: 0;
  width: 100%;
  height: 100%;
  border: 0;
  outline: none;
  resize: none;
  background: transparent;
  color: transparent;
  caret-color: var(--accent);
  overflow: auto;
}

.editor-input::selection {
  background: rgba(124, 199, 255, 0.28);
  color: transparent;
}

.editor.read-only {
  background: #121a14;
}

.editor.read-only .editor-input {
  caret-color: transparent;
}

/* syntax colors */
.t-kw {
  color: #ff8fb1;
}
.t-str {
  color: #b5e48c;
}
.t-num {
  color: #ffb454;
}
.t-com {
  color: #7d7196;
  font-style: italic;
}
.t-type {
  color: #7cc7ff;
}
.t-fn {
  color: #ffd866;
}
.t-const {
  color: #f7a26c;
}
.t-prop {
  color: #d9ccf2;
}
.t-br {
  color: #b8acd0;
}
.t-op {
  color: #ff9e64;
}

/* ------------------------------------------------------------ assets */

.asset-preview {
  overflow: auto;
  background: var(--code-bg);
}

.asset {
  max-width: 520px;
  margin: 40px auto;
  padding: 0 24px;
  text-align: center;
  line-height: 1.6;
  color: var(--muted);
}

.asset h3 {
  color: var(--text);
  font-family: var(--mono);
  margin: 20px 0 8px;
}

.asset code {
  color: var(--text);
  background: var(--panel-3);
  padding: 1px 6px;
  border-radius: 5px;
}

.asset-image {
  display: inline-block;
  padding: 24px;
  border-radius: 16px;
  background-color: #2b2336;
  background-image: linear-gradient(45deg, #33293f 25%, transparent 25%),
    linear-gradient(-45deg, #33293f 25%, transparent 25%), linear-gradient(45deg, transparent 75%, #33293f 75%),
    linear-gradient(-45deg, transparent 75%, #33293f 75%);
  background-size: 24px 24px;
  background-position: 0 0, 0 12px, 12px -12px, -12px 0;
}

.asset-image img {
  width: 256px;
  height: 256px;
  image-rendering: pixelated;
  display: block;
}

.asset-sound .play-sound {
  background: var(--panel-2);
  border: 1px solid var(--border);
  border-radius: 999px;
  padding: 18px 30px;
  font-size: 18px;
}

.asset-sound .play-sound:hover {
  background: var(--panel-3);
}

.empty {
  display: grid;
  place-items: center;
  height: 100%;
  color: var(--faint);
}

.toast {
  position: fixed;
  bottom: 24px;
  left: 50%;
  transform: translateX(-50%);
  background: var(--panel-3);
  border: 1px solid var(--border);
  padding: 8px 16px;
  border-radius: 999px;
  font-size: 14px;
  box-shadow: 0 8px 30px rgba(0, 0, 0, 0.5);
  z-index: 50;
}

.load-error {
  color: var(--bad);
  margin-top: 30px;
}

/* ------------------------------------------------------------ small screens */

@media (max-width: 900px) {
  #app {
    grid-template-columns: 1fr;
    grid-template-rows: 60vh 100vh;
    height: auto;
    overflow: visible;
  }

  #split-guide {
    display: none;
  }

  .workbench {
    grid-row: 2;
    grid-template-columns: 130px 1fr;
    height: 100vh;
  }

  .files-header {
    flex-direction: column;
    align-items: flex-start;
    height: auto;
    gap: 6px;
  }

  /* 16px stops iOS zooming in on the editor; the whole editor changes so the layers stay aligned. */
  .editor {
    font-size: 16px;
  }
}