* {
  box-sizing: border-box;
}
body {
  margin: 0;
  background: #f8fafc;
  color: #172c3c;
  font-family: Arial, Helvetica, sans-serif;
}
header {
  padding: 25px 36px;
  display: flex;
  justify-content: space-between;
  align-items: center;
  border-bottom: 1px solid #dce3ea;
}
.brand {
  font-size: 25px;
  font-weight: 800;
  text-decoration: none;
  color: inherit;
  letter-spacing: 1px;
}
.brand span {
  font-size: 15px;
  font-weight: 400;
  letter-spacing: 0;
  color: #607586;
}
header p {
  font-size: 12px;
  margin: 8px 0 0;
  color: #607586;
}
.badge {
  font-size: 10px;
  letter-spacing: 1.6px;
  border: 1px solid #bdccda;
  border-radius: 30px;
  padding: 9px 13px;
  white-space: nowrap;
}
main {
  display: grid;
  grid-template-columns: minmax(0, 1fr) 320px;
  max-width: 1700px;
  margin: auto;
  min-height: calc(100vh - 154px);
}
.viewport {
  position: relative;
  min-height: 620px;
  overflow: hidden;
  background: #edf1f5;
}
#scene {
  display: block;
  width: 100%;
  height: 100%;
  position: absolute;
  inset: 0;
}
.overlay {
  position: absolute;
  top: 24px;
  left: 24px;
  max-width: 85%;
  font-size: 12px;
  padding: 12px 16px;
  border-radius: 6px;
  background: #ffffffed;
  display: flex;
  align-items: center;
  gap: 9px;
}
.dot {
  height: 7px;
  width: 7px;
  border-radius: 50%;
  background: #398383;
}
.hint {
  position: absolute;
  bottom: 24px;
  left: 24px;
  font-size: 12px;
  color: #496172;
}
aside {
  padding: 30px 26px;
  background: #fff;
  border-left: 1px solid #dce3ea;
}
.eyebrow {
  font-size: 10px;
  letter-spacing: 1.5px;
  font-weight: bold;
  color: #63808e;
}
h1 {
  font-size: 29px;
  line-height: 1.18;
  letter-spacing: -0.8px;
  margin: 13px 0;
}
.intro {
  font-size: 13px;
  line-height: 1.65;
  color: #607586;
  margin-bottom: 25px;
}
fieldset {
  padding: 0;
  border: 0;
  margin: 0;
}
label {
  display: block;
  font-size: 12px;
  font-weight: bold;
  margin: 16px 0 8px;
}
select {
  width: 100%;
  padding: 11px 10px;
  border: 1px solid #ccd6df;
  border-radius: 5px;
  background: #fff;
  font-size: 13px;
  color: #213c4b;
}
.note {
  font-size: 11px;
  line-height: 1.6;
  color: #708491;
}
.buttons {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 6px;
  margin-top: 17px;
}
.buttons + .buttons {
  grid-template-columns: 0.8fr 1.2fr 1fr;
  margin-top: 8px;
}
.buttons > button {
  min-width: 0;
  padding: 11px 4px;
  white-space: nowrap;
}
button {
  cursor: pointer;
  border: 1px solid #ccd6df;
  border-radius: 5px;
  padding: 11px 13px;
  background: #fff;
  color: #244453;
  font-size: 12px;
}
button.primary {
  background: #204d60;
  border-color: #204d60;
  color: #fff;
  flex: 1;
}
button:disabled,
fieldset:disabled {
  opacity: 0.55;
  cursor: wait;
}
.check {
  font-weight: 400;
  display: flex;
  gap: 8px;
  align-items: center;
}
.check input {
  accent-color: #204d60;
}
.text-button {
  border: 0;
  padding: 0;
  color: #587685;
}
.divider {
  border-top: 1px solid #e2e8ee;
  margin: 23px 0;
}
#depth {
  width: 100%;
  height: auto;
  aspect-ratio: 32/18;
  image-rendering: pixelated;
  background: #1e313f;
  border-radius: 5px;
  margin-top: 12px;
}
dl {
  font-size: 11px;
  margin: 18px 0;
}
dl div {
  display: flex;
  justify-content: space-between;
  margin: 9px 0;
}
dt {
  color: #708491;
}
dd {
  margin: 0;
  font-variant-numeric: tabular-nums;
}
footer {
  font-size: 11px;
  color: #708491;
  padding: 17px 36px;
  border-top: 1px solid #dce3ea;
}
#error {
  position: absolute;
  bottom: 60px;
  left: 24px;
  right: 24px;
  background: #fff0ed;
  color: #9b392b;
  padding: 18px;
  border-radius: 6px;
  font-size: 13px;
  white-space: pre-wrap;
}
:focus-visible {
  outline: 3px solid #60a5ca;
  outline-offset: 3px;
}
@media (max-width: 800px) {
  header {
    padding: 18px;
  }
  header p {
    max-width: 260px;
  }
  main {
    grid-template-columns: 1fr;
  }
  .viewport {
    min-height: 55vh;
  }
  aside {
    border-left: 0;
    border-top: 1px solid #dce3ea;
    padding: 24px;
  }
  #depth {
    max-width: 280px;
  }
  footer {
    padding: 16px;
  }
  .badge {
    font-size: 8px;
    padding: 7px;
  }
  .brand span {
    font-size: 12px;
  }
}

#boundary-note {
  position: absolute;
  top: 76px;
  left: 24px;
  right: 24px;
  padding: 15px;
  background: #fff4dcef;
  color: #78520d;
  border: 1px solid #dfbd75;
  border-radius: 6px;
  font-size: 13px;
}

#terrain-editor {
  margin-top: 22px;
  border-top: 1px solid #dce3ea;
  padding-top: 16px;
}
summary {
  cursor: pointer;
  font-size: 13px;
  font-weight: bold;
}
#custom-fields input {
  width: 100%;
  padding: 9px 10px;
  border: 1px solid #ccd6df;
  border-radius: 5px;
  font: inherit;
  font-size: 13px;
}
#custom-error {
  color: #9b392b;
  font-size: 12px;
  line-height: 1.5;
}
#generate {
  margin-top: 8px;
}
#custom-inverted-label {
  line-height: 1.5;
}
@media (min-width: 801px) {
  .viewport {
    position: sticky;
    top: 0;
    height: calc(100vh - 24px);
    max-height: 1100px;
  }
}

[hidden] {
  display: none !important;
}

.brand {
  display: inline-flex;
  align-items: center;
  gap: 9px;
}
.brand img {
  display: block;
  flex-shrink: 0;
}
.intro strong {
  font-weight: 700;
  color: #233447;
}
aside > h1:first-child {
  margin-top: 0;
}
@media (max-width: 480px) {
  .brand {
    gap: 6px;
    font-size: 22px;
  }
  .brand img {
    width: 28px;
    height: 28px;
  }
  .brand span {
    font-size: 11px;
  }
}

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

main {
  grid-template-columns: minmax(0, 1fr) 390px;
}
h2 {
  font-size: 15px;
  margin: 0 0 8px;
}
.control-section {
  margin-bottom: 22px;
}
.control-section > .note {
  margin: 0 0 10px;
}
.choice-grid {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 7px;
}
.choice-grid button {
  text-align: left;
  display: flex;
  flex-direction: column;
  gap: 5px;
  min-height: 46px;
  padding: 11px 12px;
  line-height: 1.35;
}
.choice-grid button small {
  font-size: 10px;
  color: #708491;
}
.choice-grid button:hover {
  background: #edf4f7;
  border-color: #91aebb;
}
.choice-grid button[aria-pressed="true"] {
  background: #204d60;
  border-color: #204d60;
  color: white;
}
.choice-grid button[aria-pressed="true"] small {
  color: #d6e8ef;
}
.keyboard-guide {
  padding: 15px;
  background: #edf4f7;
  border-radius: 8px;
  margin-top: 8px;
}
.keyboard-guide strong {
  font-size: 13px;
}
.key-row {
  display: flex;
  align-items: center;
  gap: 6px;
  margin-top: 10px;
  font-size: 11px;
}
.key-row span {
  margin-left: 4px;
}
kbd {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  width: 27px;
  height: 27px;
  border: 1px solid #bdccda;
  border-bottom-width: 3px;
  border-radius: 5px;
  background: white;
  font: 14px Arial;
}
.keyboard-guide .note {
  margin-bottom: 0;
}
.buttons + .buttons.scene-tools {
  grid-template-columns: repeat(2, minmax(0, 1fr));
}
#custom-fields {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 0 12px;
}
#custom-fields label {
  line-height: 1.4;
  min-height: 34px;
}
#terrain-editor > h2 {
  margin: 0;
}
#terrain-editor > .note {
  margin-bottom: 0;
}
@media (max-width: 800px) {
  main {
    grid-template-columns: 1fr;
  }
  .choice-grid {
    grid-template-columns: repeat(3, minmax(0, 1fr));
  }
}
@media (max-width: 480px) {
  .choice-grid {
    grid-template-columns: repeat(2, minmax(0, 1fr));
  }
}

@media (min-width: 801px) {
  main {
    grid-template-columns: minmax(0, 1fr) 430px;
  }
  aside {
    padding: 24px;
  }
  aside h1 {
    font-size: 25px;
  }
  .intro {
    margin-bottom: 18px;
    line-height: 1.5;
  }
  .choice-grid {
    grid-template-columns: repeat(3, minmax(0, 1fr));
  }
  .choice-grid button {
    padding: 9px;
    font-size: 11px;
    min-height: 43px;
  }
  #motion button {
    min-height: 53px;
  }
  .keyboard-guide {
    margin: 0 0 20px;
    padding: 12px;
  }
  .key-row {
    margin-top: 7px;
  }
  .control-section {
    margin-bottom: 18px;
  }
}
.field-label {
  font-size: 12px;
  font-weight: bold;
  margin: 16px 0 8px;
}
/* Synchronized reference preview, kept separate from the physical rollout. */
#reference-panel {
  position: absolute;
  right: 18px;
  top: 18px;
  width: 236px;
  border: 1px solid #c6d5de;
  border-radius: 10px;
  background: #f8fafcf5;
  box-shadow: 0 5px 22px #18324616;
  overflow: hidden;
  z-index: 2;
}
.reference-heading {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 6px 8px 6px 11px;
  gap: 4px;
}
.reference-heading strong {
  font-size: 11px;
}
.reference-heading strong span {
  font-weight: 400;
  color: #607586;
}
.reference-heading > div {
  display: flex;
  gap: 3px;
}
.reference-heading button {
  border: 0;
  background: transparent;
  font-size: 16px;
  padding: 3px 7px;
  min-width: 28px;
}
#reference-body {
  position: relative;
}
#reference-scene {
  display: block;
  width: 100%;
  height: 182px;
  touch-action: none;
}
#reference-label {
  position: absolute;
  bottom: 0;
  left: 0;
  right: 0;
  margin: 0;
  padding: 6px 10px;
  font-size: 10px;
  color: #405a66;
  background: #edf3f6dd;
  overflow: hidden;
  text-overflow: ellipsis;
  white-space: nowrap;
  pointer-events: none;
}
#reference-panel.expanded {
  width: min(460px, calc(100% - 36px));
}
#reference-panel.expanded #reference-scene {
  height: 340px;
}
.motion-import {
  border-top: 1px solid #e2e8ee;
  margin-top: 18px;
  padding-top: 14px;
}
.motion-import input {
  width: 100%;
  font-size: 12px;
}
.motion-import input[type="number"] {
  padding: 9px;
  border: 1px solid #ccd6df;
  border-radius: 5px;
}
.motion-import a {
  color: #315e70;
}
#import-error {
  color: #9b392b;
  font-size: 12px;
  line-height: 1.5;
}
#import-result {
  overflow-wrap: anywhere;
}
#play-imported {
  width: 100%;
  border-color: #547d90;
}
#play-imported[hidden] {
  display: none;
}
@media (max-width: 800px) {
  #reference-panel {
    top: 12px;
    right: 12px;
    width: 150px;
  }
  .reference-heading {
    padding: 4px 5px 4px 8px;
  }
  .reference-heading strong span {
    display: none;
  }
  #reference-scene {
    height: 114px;
  }
  #reference-panel.expanded #reference-scene {
    height: 260px;
  }
  .overlay {
    max-width: calc(100% - 205px);
    left: 12px;
    top: 12px;
    padding: 9px;
    font-size: 10px;
  }
}

/* Compact macOS-style window controls; the hit area exceeds the visible dot. */
.reference-heading {
  justify-content: flex-start;
  gap: 7px;
  padding: 5px 9px;
  background: #f4f6f8;
  border-bottom: 1px solid #dce3e880;
}
.reference-heading > div {
  order: -1;
  gap: 0;
  flex: none;
}
.reference-heading strong {
  font-size: 10px;
  font-weight: 600;
  letter-spacing: 0.01em;
  white-space: nowrap;
}
.reference-heading strong span {
  font-size: 9px;
  color: #81909c;
}
.reference-heading button {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  position: relative;
  width: 22px;
  height: 24px;
  min-width: 22px;
  padding: 0;
  border: 0;
  border-radius: 50%;
  font-size: 12px;
  line-height: 1;
  transition: filter 0.15s ease;
}
#reference-toggle {
  order: -1;
  color: #805a10;
  background: radial-gradient(circle, #febc2e 0 5.3px, #dea123 5.3px 6px, transparent 6px);
}
#reference-expand {
  color: #10651e;
  background: radial-gradient(circle, #28c840 0 5.3px, #1eab34 5.3px 6px, transparent 6px);
}
#reference-expand svg {
  width: 10px;
  height: 10px;
}
.reference-heading button:hover {
  filter: brightness(0.94);
}
.reference-heading button:focus-visible {
  outline: 2px solid #65889a;
  outline-offset: 1px;
}
#reference-expand .shrink-symbol,
#reference-expand[aria-pressed="true"] .expand-symbol {
  display: none;
}
#reference-expand[aria-pressed="true"] .shrink-symbol {
  display: inline;
}
@media (max-width: 800px) {
  .reference-heading {
    padding: 4px 6px;
    gap: 4px;
  }
}

#force-note {
  position: absolute;
  bottom: 55px;
  left: 24px;
  max-width: calc(100% - 48px);
  padding: 9px 12px;
  border: 1px solid #dcb7a6;
  border-radius: 6px;
  background: #fff8f2ed;
  color: #875039;
  font-size: 11px;
  pointer-events: none;
}
.mouse-guide {
  border-top: 1px solid #d5e2e8;
  margin-top: 12px;
  padding-top: 10px;
}
.mouse-guide strong {
  display: block;
  font-size: 11px;
  margin-bottom: 3px;
}
.hint {
  max-width: calc(100% - 48px);
  line-height: 1.6;
  pointer-events: none;
}

.simulation-controls {
  margin-top: 20px;
  padding-top: 16px;
  border-top: 1px solid #dce3ea;
}
.simulation-controls > .buttons:first-of-type {
  margin-top: 10px;
}