:root {
  --navy: #102744;
  --cream: #fff6da;
  --copper: #b76b3a;
  --cyan: #49c9db;
  --ink: #102744;
}

* {
  box-sizing: border-box;
}
body {
  margin: 0;
  min-width: 320px;
  background: radial-gradient(circle at 75% 10%, #25486b, #08172c 60%);
  color: var(--cream);
  font:
    18px/1.45 system-ui,
    sans-serif;
}
button,
.link-button {
  min-height: 48px;
  padding: 10px 16px;
  border: 3px solid var(--navy);
  border-radius: 12px;
  font: inherit;
  font-weight: 800;
  cursor: pointer;
}
button:focus-visible,
a:focus-visible {
  outline: 4px solid #ffbc45;
  outline-offset: 3px;
}
.primary {
  background: #ffbc45;
  color: var(--navy);
}
.secondary {
  background: var(--cream);
  color: var(--navy);
}
button[aria-pressed="true"] {
  outline: 5px solid #ffbc45;
  background: #9e8cff;
}
.skip-link {
  position: absolute;
  left: 10px;
  top: -70px;
  z-index: 4;
  padding: 10px;
  color: var(--ink);
  background: #fff;
}
.skip-link:focus {
  top: 10px;
}
.game-header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 10px;
  padding: 10px 4vw;
  background: #08172c;
  border-bottom: 2px solid #557896;
}
.home-link {
  color: var(--cream);
  font-weight: 800;
}
.game-header p {
  font-size: 0.8rem;
  letter-spacing: 0.1em;
}
.game-header button {
  min-height: 44px;
}
.card,
.model-card {
  width: min(760px, 100%);
  margin: 20px auto;
  padding: clamp(18px, 4vw, 38px);
  border: 5px solid var(--copper);
  border-radius: 24px;
  background: var(--cream);
  color: var(--ink);
  box-shadow: 0 9px #07162a;
}
main {
  padding: 10px 16px 42px;
}
.welcome {
  text-align: center;
  margin-top: 8vh;
}
.eyebrow {
  font-weight: 900;
  letter-spacing: 0.08em;
  font-size: 0.82rem;
}
.boundary,
.fixed-caption {
  font-size: 0.9rem;
}
.topline {
  width: min(760px, 100%);
  margin: auto;
  display: flex;
  justify-content: space-between;
  align-items: center;
}
.topline p {
  font-weight: 900;
}
.topline ol {
  display: flex;
  gap: 5px;
  padding: 0;
  list-style: none;
}
.topline li {
  display: grid;
  width: 28px;
  height: 28px;
  border: 2px solid var(--cream);
  border-radius: 50%;
  place-items: center;
}
.topline li.done {
  background: #ffbc45;
  color: var(--navy);
}
.model-card {
  position: relative;
  text-align: center;
  background: var(--navy);
  color: var(--cream);
}
.rays {
  color: #ffbc45;
  font-weight: 900;
  letter-spacing: 0.08em;
  text-align: right;
}
.step-stops circle {
  fill: #ffbc45;
  stroke: var(--navy);
  stroke-width: 2px;
}
.model-status {
  margin: 8px 0 0;
  font-size: 0.85rem;
  text-align: left;
}
.model-boundary {
  margin: 8px 0 0;
  font-size: 0.8rem;
  text-align: left;
}
.model-card.model-reminder {
  box-shadow:
    0 0 0 5px #ffbc45,
    0 9px #07162a;
}
.model-card.model-reminder .rays {
  text-decoration: underline;
}
.model-card.model-reminder .fixed-light-boundary {
  stroke: #ffbc45;
  stroke-width: 7px;
}
.model-card svg {
  display: block;
  width: min(100%, 430px);
  margin: auto;
}
.svg-label,
.marker-text,
.axis-inset text {
  font: 700 12px system-ui;
  fill: #fff6da;
}
.marker-text {
  fill: #102744;
}
.card h1 {
  line-height: 1.1;
}
.actions,
.tiles {
  display: flex;
  flex-wrap: wrap;
  gap: 10px;
}
.actions {
  margin-top: 12px;
}
.tiles h2 {
  width: 100%;
  margin: 0;
  font-size: 1rem;
}
.tiles button,
fieldset button {
  min-height: 48px;
  flex: 1 1 220px;
  background: #d9f7f7;
}
fieldset {
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
  margin: 12px 0;
  border: 2px solid #557896;
  border-radius: 12px;
}
fieldset legend {
  font-weight: 800;
}
#hint,
#selected-explanation {
  margin-top: 12px;
  padding: 12px;
  border-left: 6px solid var(--copper);
  background: #d9f7f7;
}
#selected-explanation {
  font-weight: 700;
}
dialog {
  border: 5px solid var(--copper);
  border-radius: 20px;
  background: var(--cream);
  color: var(--ink);
}
.link-button {
  display: inline-flex;
  align-items: center;
  text-decoration: none;
}

@media (min-width: 900px) {
  #observatory {
    display: grid;
    grid-template-columns: minmax(340px, 1fr) minmax(360px, 1fr);
    gap: 20px;
    max-width: 1200px;
    margin: auto;
  }
  .topline,
  #completion,
  #explanations {
    grid-column: 1 / -1;
  }
  .model-card {
    height: max-content;
    margin: 0;
  }
  .card {
    width: 100%;
    margin: 0;
  }
  .welcome {
    width: min(760px, 100%);
  }
}

@media (prefers-reduced-motion: reduce) {
  *,
  *::before,
  *::after {
    animation: none !important;
    transition: none !important;
  }
}
@media (max-width: 380px) {
  body {
    font-size: 16px;
  }
  .game-header p {
    display: none;
  }
  .topline {
    align-items: flex-start;
    flex-direction: column;
  }
  .topline ol {
    margin-top: 0;
  }
  .axis-inset {
    display: none;
  }
}

[hidden] {
  display: none !important;
}

.home-link {
  display: inline-flex;
  align-items: center;
  min-height: 44px;
}
.stop-legend summary {
  display: list-item;
  min-height: 44px;
  padding: 10px 0;
  cursor: pointer;
  text-align: left;
}
.game-header > div {
  display: flex;
  gap: 8px;
  align-items: center;
}
@media (min-width: 700px) and (max-width: 899px) {
  #observatory {
    display: grid;
    grid-template-columns: minmax(0, 1fr) minmax(0, 1fr);
    gap: 14px;
  }
  .topline,
  #completion,
  #explanations {
    grid-column: 1 / -1;
  }
  .model-card,
  .card {
    margin: 0;
    padding: 16px;
  }
  .model-card svg {
    width: min(100%, 280px);
  }
  .model-card {
    height: max-content;
  }
}
@media (max-width: 699px) {
  body {
    font-size: 16px;
  }
  main {
    padding: 10px 12px 24px;
  }
  .game-header {
    padding: 6px 12px;
  }
  .game-header p {
    display: none;
  }
  .topline {
    flex-direction: row;
    align-items: center;
    gap: 6px;
  }
  .topline p {
    font-size: 0.75rem;
  }
  .topline ol {
    gap: 3px;
  }
  .topline li {
    width: 22px;
    height: 22px;
    font-size: 0.7rem;
  }
  .card,
  .model-card {
    padding: 12px;
    margin: 8px auto;
    border-width: 3px;
  }
  .model-card svg {
    width: min(100%, 210px);
  }
  .fixed-caption,
  .model-boundary {
    font-size: 0.75rem;
    margin: 6px 0;
  }
  .rays {
    font-size: 0.75rem;
  }
  .stop-legend {
    font-size: 0.8rem;
  }
  .card h1 {
    font-size: 1.35rem;
    margin: 8px 0;
  }
  .card p {
    margin: 8px 0;
  }
  .eyebrow {
    font-size: 0.7rem;
  }
  fieldset {
    margin: 8px 0;
    padding: 8px;
  }
  fieldset button {
    flex-basis: 100px;
    font-size: 0.85rem;
    padding: 8px;
  }
}
@media (max-height: 500px) and (min-width: 600px) {
  .game-header {
    padding: 4px 12px;
  }
  main {
    padding: 8px 12px;
  }
  .welcome {
    margin: 0 auto;
    padding: 12px 16px;
    display: grid;
    grid-template-columns: 1fr 220px;
    gap: 8px 14px;
    text-align: left;
  }
  .welcome .eyebrow {
    grid-column: 1 / -1;
    margin: 0;
  }
  .welcome h1 {
    font-size: 1.4rem;
    margin: 0;
  }
  .welcome p {
    font-size: 0.85rem;
    margin: 0;
  }
  .welcome #start-button {
    grid-column: 2;
    grid-row: 2 / span 2;
    align-self: center;
  }
  .welcome #example {
    grid-column: 1 / -1;
  }
}
@media (max-height: 500px) and (min-width: 600px) {
  .topline p {
    font-size: 0.8rem;
    margin: 6px 0;
  }
  .topline ol {
    margin: 6px 0;
  }
  .card {
    padding: 12px;
  }
  .card h1 {
    font-size: 1.2rem;
    line-height: 1.15;
    margin: 6px 0;
  }
  .card p {
    font-size: 0.8rem;
    margin: 6px 0;
  }
  fieldset {
    margin: 6px 0;
    padding: 6px;
  }
  fieldset legend,
  fieldset button {
    font-size: 0.8rem;
  }
  fieldset button {
    flex-basis: 100px;
    padding: 8px;
  }
}

.marker-text {
  fill: #fff6da;
  stroke: #102744;
  stroke-width: 3px;
  paint-order: stroke fill;
  stroke-linejoin: round;
}
.axis-inset text {
  fill: #102744;
}
.notebook-disclosure summary {
  min-height: 44px;
  padding-block: 10px;
  cursor: pointer;
}
.completion-actions {
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
}