:root {
  --bg: #f7f5ef;
  --panel: #fffdf8;
  --ink: #161616;
  --muted: #6b6860;
  --line: #d9d5ca;
  --good: #1f7a4a;
  --bad: #c2362b;
  --accent: #161616;
  --nodata: #b9b4a8;
}
@media (prefers-color-scheme: dark) {
  :root:not([data-theme="light"]) {
    --bg: #15151a; --panel: #1d1d23; --ink: #eceae4; --muted: #9a978f; --line: #34343c;
    --good: #4cc38a; --bad: #f0675b; --accent: #eceae4; --nodata: #55534e;
  }
}
* { box-sizing: border-box; }
html, body { margin: 0; }
body {
  background: var(--bg); color: var(--ink);
  font: 16px/1.5 system-ui, -apple-system, "Segoe UI", Roboto, sans-serif;
  min-height: 100vh; display: flex; flex-direction: column;
}
header {
  display: flex; justify-content: space-between; align-items: center; flex-wrap: wrap; gap: 8px;
  padding: 12px 16px; border-bottom: 1px solid var(--line);
}
.brand { font-weight: 800; font-size: 1.15rem; color: var(--ink); text-decoration: none; }
nav a { color: var(--muted); text-decoration: none; margin-left: 16px; }
nav a:hover { color: var(--ink); }
main { width: 100%; max-width: 760px; margin: 0 auto; padding: 24px 16px 40px; flex: 1; }
footer { text-align: center; padding: 12px 16px 20px; }
h1 { font-size: clamp(1.6rem, 4vw, 2.2rem); line-height: 1.2; margin: 0 0 12px; }
h2 { margin: 0 0 8px; }
h3 { margin: 28px 0 8px; font-size: 1rem; }
.lede { font-size: 1.05rem; }
.rules { padding-left: 20px; color: var(--muted); }
.small { font-size: .875rem; }
.muted { color: var(--muted); }
kbd {
  font: 600 .75em ui-monospace, monospace; border: 1px solid currentColor; border-radius: 4px;
  padding: 0 4px; opacity: .7;
}
label.name { display: block; margin: 20px 0 12px; font-weight: 600; }
label.name input {
  display: block; width: 100%; max-width: 320px; margin-top: 6px; padding: 10px 12px;
  font: inherit; color: var(--ink); background: var(--panel); border: 1px solid var(--line); border-radius: 8px;
}
button, .btn {
  font: inherit; font-weight: 600; cursor: pointer; border-radius: 10px; padding: 10px 18px;
  border: 1px solid var(--line); background: var(--panel); color: var(--ink); text-decoration: none;
  display: inline-block;
}
button.primary { background: var(--accent); color: var(--bg); border-color: var(--accent); }
button:disabled { opacity: .5; cursor: default; }
.row { display: flex; gap: 12px; flex-wrap: wrap; margin-top: 16px; }

/* play */
.hud { display: flex; justify-content: space-between; color: var(--muted); font-variant-numeric: tabular-nums; }
.coord {
  text-align: center; font: 800 clamp(2.4rem, 11vw, 4.6rem)/1.1 ui-monospace, "SF Mono", Menlo, monospace;
  margin: 48px 0 6px; letter-spacing: -.02em; font-variant-numeric: tabular-nums;
}
.coord-sub { text-align: center; color: var(--muted); font-variant-numeric: tabular-nums; min-height: 1.5em; }
.answers { display: grid; grid-template-columns: 1fr 1fr; gap: 14px; margin: 36px 0 16px; }
.ans { font-size: 1.35rem; padding: 26px 10px; border-radius: 14px; border-width: 2px; }
.ans.land { background: #fff; color: #111; border-color: #111; }
.ans.water { background: #111; color: #fff; border-color: #111; }
@media (prefers-color-scheme: dark) {
  :root:not([data-theme="light"]) .ans.land { border-color: #fff; }
  :root:not([data-theme="light"]) .ans.water { border-color: #555; }
}
.ans:active { transform: scale(.98); }
.feedback { text-align: center; min-height: 3.2em; font-weight: 600; }
.feedback .ok { color: var(--good); }
.feedback .no { color: var(--bad); }
.feedback .crowd { display: block; font-weight: 400; color: var(--muted); font-size: .9rem; }

/* summary */
.stats { display: grid; grid-template-columns: repeat(3, 1fr); gap: 12px; margin: 16px 0 8px; }
.stats > div {
  background: var(--panel); border: 1px solid var(--line); border-radius: 12px; padding: 12px; text-align: center;
}
.big { display: block; font-size: 1.8rem; font-weight: 800; font-variant-numeric: tabular-nums; }
.lbl { color: var(--muted); font-size: .85rem; }
canvas { width: 100%; height: auto; display: block; border-radius: 6px; margin-top: 12px; image-rendering: pixelated; }
.legend { display: flex; align-items: center; gap: 6px; flex-wrap: wrap; }
.sw { display: inline-block; width: 12px; height: 12px; border-radius: 50%; border: 1px solid #888; margin-left: 10px; }
.sw-land { background: #fff; } .sw-water { background: #111; } .sw-wrong { background: transparent; border: 2px solid var(--bad); }

/* tabs + tables */
.tabs { display: flex; gap: 6px; flex-wrap: wrap; margin: 12px 0 4px; }
.tab { padding: 6px 12px; font-size: .9rem; border-radius: 999px; }
.tab.active { background: var(--accent); color: var(--bg); border-color: var(--accent); }
table.board { width: 100%; border-collapse: collapse; margin-top: 8px; font-variant-numeric: tabular-nums; font-size: .95rem; }
.board th, .board td { padding: 6px 8px; border-bottom: 1px solid var(--line); text-align: right; }
.board th:nth-child(2), .board td:nth-child(2) { text-align: left; }
.board th { color: var(--muted); font-weight: 600; font-size: .8rem; }
@media (max-width: 520px) {
  .board th:nth-child(4), .board td:nth-child(4), .board th:nth-child(6), .board td:nth-child(6) { display: none; }
}
ol.hard { padding-left: 22px; font-variant-numeric: tabular-nums; }