:root {
  color-scheme: dark;
  --water: #061c2d;
  --panel: #0b2e43;
  --line: #2a5369;
  --ink: #effaff;
  --muted: #bed2df;
  --aqua: #86ede1;
  --gold: #ffd383;
  --body: "Instrument Sans", system-ui, sans-serif;
  font: 1rem/1.55 var(--body);
  color: var(--ink);
  background: var(--water);
}
*, *::before, *::after { box-sizing: border-box; }
body { margin: 0; background: radial-gradient(ellipse at 70% 15%, #103b51, transparent 45rem); }
h1, h2, h3, p { margin: 0; }
h1, h2, h3 { line-height: 1.12; letter-spacing: -.035em; }
a { color: var(--aqua); text-underline-offset: .23em; }
button, input { font: inherit; }
button { cursor: pointer; }
[hidden] { display: none !important; }
:focus-visible { outline: 2px solid var(--gold); outline-offset: 4px; }
.shell { width: min(70rem, calc(100% - 3rem)); margin-inline: auto; }
.skip { position: absolute; top: .5rem; left: .5rem; transform: translateY(-180%); z-index: 2; background: var(--water); padding: .65rem; }
.skip:focus { transform: none; }
.site-header { border-bottom: 1px solid var(--line); background: #071e30; }
.header-inner { min-height: 4.25rem; display: flex; align-items: center; justify-content: space-between; gap: .75rem; }
.brand { display: flex; align-items: center; gap: .65rem; font-weight: 780; color: var(--ink); text-decoration: none; }
.brand-icon { display: grid; place-items: center; width: 2.1rem; height: 2.1rem; border: 1px solid #417584; border-radius: 50%; color: var(--aqua); font-size: 1.55rem; line-height: 1; }
nav { display: flex; gap: clamp(.65rem, 2.5vw, 1.7rem); }
nav a { color: var(--muted); text-decoration: none; }
nav a:hover, nav .nav-play { color: var(--aqua); }
.hero {
  margin-top: 1.4rem; min-height: clamp(13rem, 26vw, 18.5rem); display: flex; align-items: center; padding: clamp(1.2rem, 5vw, 3.5rem);
  background: linear-gradient(90deg, #06273bed 6%, #06273bbc 48%, #06273b00 83%), url("./ocean-hero.webp") center right / cover;
  border: 1px solid #2c637d; border-radius: 1.2rem; overflow: hidden;
}
.hero h1 { font-size: clamp(2.35rem, 5vw, 4.65rem); font-weight: 810; max-width: 12ch; }
.hero h1 span { color: var(--aqua); }
.hero p { margin-top: .85rem; color: #e0edf7; max-width: 43ch; }
.play-grid { display: grid; grid-template-columns: minmax(0, 2fr) minmax(15rem, 1fr); gap: 1rem; margin-block: 1rem 2.5rem; align-items: start; }
.panel { background: var(--panel); border: 1px solid var(--line); border-radius: 1rem; padding: clamp(1rem, 3vw, 1.7rem); }
.game-panel { min-height: 15rem; }
.game-heading { display: flex; align-items: center; justify-content: space-between; gap: .7rem; flex-wrap: wrap; padding-bottom: 1rem; margin-bottom: 1.1rem; border-bottom: 1px solid var(--line); }
.game-heading h2 { font-size: clamp(1.25rem, 3vw, 1.8rem); }
.game-stats { display: flex; flex-wrap: wrap; gap: .5rem; font-size: .83rem; font-variant-numeric: tabular-nums; }
.game-stats span { background: #082436; color: var(--muted); border: 1px solid var(--line); border-radius: 1rem; padding: .19rem .56rem; }
#depth { color: var(--aqua); font-weight: 750; }
#timer[data-low="true"] { color: var(--gold); }
.game-panel p, .score-intro, .guide p { color: var(--muted); }
.start-actions, .round-actions { display: flex; align-items: center; gap: .7rem 1rem; flex-wrap: wrap; margin-top: 1rem; }
.primary, .secondary, .text-button { min-height: 2.65rem; padding: .53rem .9rem; border-radius: .58rem; font-weight: 700; }
.primary { background: var(--aqua); color: #062735; border: 1px solid transparent; }
.primary:hover { background: #b0fff1; }
.secondary { background: #103e52; color: var(--aqua); border: 1px solid #397084; }
.secondary:hover { background: #194b5f; }
.text-button { color: var(--muted); background: transparent; border: 1px solid transparent; padding-inline: .3rem; text-decoration: underline; text-underline-offset: .2em; }
.text-button:hover { color: var(--ink); }
button:disabled { opacity: .55; cursor: default; }
.toggle { display: inline-flex; align-items: center; gap: .4rem; color: var(--muted); cursor: pointer; min-height: 2.65rem; }
.toggle input { width: 1.2rem; height: 1.2rem; accent-color: var(--aqua); }
.category { color: var(--aqua) !important; font-size: .85rem; margin-bottom: .45rem; }
#prompt, #result-heading { font-size: clamp(1.4rem, 4vw, 2rem); }
#answer-form { margin-top: 1rem; }
#answer-form label { display: block; margin-bottom: .35rem; color: var(--muted); }
.answer-row { display: flex; gap: .6rem; }
.answer-row input { flex: 1; min-width: 4rem; width: 100%; padding: .6rem .65rem; border: 1px solid #4b7388; border-radius: .58rem; background: #071f30; color: var(--ink); }
.feedback:not(:empty), .hint { margin-top: 1rem; border-left: 2px solid var(--aqua); padding: .55rem .75rem; background: #082436; }
.hint { border-color: var(--gold); }
#next-button, #again, #result-summary { margin-top: 1rem; }
.score-panel h2 { font-size: 1.28rem; }
.score-intro { margin-block: .6rem .85rem; font-size: .9rem; }
.empty { border-top: 1px solid var(--line); padding-top: .8rem; font-size: .9rem; color: var(--muted); }
.score-panel ol { margin: 0; padding-left: 1.5rem; color: var(--aqua); font-variant-numeric: tabular-nums; }
.score-panel li { padding: .32rem .2rem; }
.score-panel li small { margin-left: .45rem; color: var(--muted); }
.guide { margin-block: 2rem; }
.section-header { border-bottom: 1px solid var(--line); padding-bottom: .7rem; margin-bottom: .9rem; }
.section-header h2 { font-size: clamp(1.45rem, 3vw, 2rem); }
.guide-grid, .comparison { display: grid; grid-template-columns: repeat(3, minmax(0, 1fr)); gap: .85rem; }
.guide article, .faq details { border: 1px solid var(--line); background: #0a283b; border-radius: .8rem; padding: 1rem; }
.guide h3 { font-size: 1.14rem; margin-bottom: .55rem; }
.comparison a { display: inline-block; margin-top: .65rem; }
.faq details + details { margin-top: .6rem; }
.faq summary { cursor: pointer; font-weight: 680; }
.faq details p { margin-top: .65rem; }
.site-footer { border-top: 1px solid var(--line); color: var(--muted); padding: 1.2rem 0; font-size: .88rem; }
.site-footer .shell { display: flex; justify-content: space-between; flex-wrap: wrap; gap: .5rem; }
@media (max-width: 700px) {
  .shell { width: calc(100% - 1.5rem); }
  .play-grid { grid-template-columns: 1fr; }
  .guide-grid, .comparison { grid-template-columns: 1fr; }
  .hero { background-position: center, 64% center; }
  .hero p { max-width: 33ch; }
}
@media (max-width: 360px) {
  .header-inner { flex-wrap: wrap; padding-block: .7rem; }
}