:root {
  --bg: #0d0d0d;
  --surface: #1a1a19;
  --surface-2: #202020;
  --border: #2c2c2a;
  --text: #ffffff;
  --text-2: #c3c2b7;
  --muted: #898781;
  --gold: #f5c243;
  --good: #0ca30c;
  --bad: #d03b3b;
  --radius: 12px;
  --shadow: 0 10px 30px rgba(0, 0, 0, 0.45);
}

* { margin: 0; padding: 0; box-sizing: border-box; }

html, body { height: 100%; }

body {
  background:
    radial-gradient(1100px 600px at 50% -10%, #16160f 0%, transparent 60%),
    var(--bg);
  color: var(--text);
  font-family: system-ui, -apple-system, "Segoe UI", sans-serif;
  min-height: 100%;
  display: flex;
  flex-direction: column;
  align-items: center;
  padding: 18px 12px 40px;
  -webkit-font-smoothing: antialiased;
}

.tabnum { font-variant-numeric: tabular-nums; }

/* Header */
header.top {
  width: 100%;
  max-width: 520px;
  display: flex;
  align-items: baseline;
  justify-content: space-between;
  gap: 12px;
  margin-bottom: 12px;
}
.brand {
  display: flex;
  align-items: baseline;
  gap: 10px;
}
.brand h1 {
  font-size: 22px;
  font-weight: 700;
  letter-spacing: 0.02em;
}
.brand h1 .a { color: var(--gold); }
.brand .tag {
  font-size: 12px;
  color: var(--muted);
  letter-spacing: 0.04em;
}

/* HUD */
.hud {
  width: 100%;
  max-width: 520px;
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 8px;
  margin-bottom: 12px;
}
.stat {
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: 10px;
  padding: 8px 10px;
  text-align: center;
  min-width: 0;
}
.stat .k {
  display: block;
  font-size: 10px;
  letter-spacing: 0.08em;
  text-transform: uppercase;
  color: var(--muted);
  margin-bottom: 3px;
}
.stat .v {
  display: block;
  font-size: 19px;
  font-weight: 700;
  color: var(--text);
  line-height: 1.1;
}
.stat.combo .v { color: var(--gold); }
.stat.hot { animation: pop 0.28s ease; }
@keyframes pop { 0% { transform: scale(1); } 40% { transform: scale(1.12); } 100% { transform: scale(1); } }

/* Toolbar */
.toolbar {
  width: 100%;
  max-width: 520px;
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
  margin-bottom: 12px;
  align-items: center;
}
button, .seg {
  font-family: inherit;
}
.btn {
  background: var(--surface);
  color: var(--text-2);
  border: 1px solid var(--border);
  border-radius: 9px;
  padding: 8px 12px;
  font-size: 13px;
  font-weight: 600;
  cursor: pointer;
  transition: background 0.12s ease, color 0.12s ease, border-color 0.12s ease;
  touch-action: manipulation;
}
.btn:hover { background: var(--surface-2); color: var(--text); }
.btn:active { transform: translateY(1px); }
.btn.primary {
  background: var(--gold);
  color: #1a1400;
  border-color: var(--gold);
}
.btn.primary:hover { filter: brightness(1.06); background: var(--gold); color: #1a1400; }
.btn.ghost { background: transparent; }
.spacer { flex: 1 1 auto; }

.seg {
  display: inline-flex;
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: 9px;
  overflow: hidden;
}
.seg button {
  background: transparent;
  color: var(--muted);
  border: 0;
  padding: 8px 12px;
  font-size: 13px;
  font-weight: 600;
  cursor: pointer;
}
.seg button.on {
  background: var(--surface-2);
  color: var(--gold);
}

.iconbtn {
  width: 38px;
  height: 38px;
  display: inline-flex;
  align-items: center;
  justify-content: center;
  font-size: 17px;
  padding: 0;
}

/* Board */
.board-wrap {
  position: relative;
  width: 100%;
  max-width: 520px;
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  box-shadow: var(--shadow);
  padding: 10px;
}
#board {
  display: block;
  width: 100%;
  height: auto;
  border-radius: 8px;
  touch-action: none;
  cursor: pointer;
  background: #121211;
}

/* Toast */
.toast {
  position: absolute;
  left: 50%;
  bottom: 16px;
  transform: translateX(-50%) translateY(10px);
  background: rgba(20, 20, 18, 0.92);
  border: 1px solid var(--border);
  color: var(--text);
  font-size: 13px;
  font-weight: 600;
  padding: 8px 14px;
  border-radius: 999px;
  opacity: 0;
  pointer-events: none;
  transition: opacity 0.25s ease, transform 0.25s ease;
  z-index: 5;
}
.toast.show { opacity: 1; transform: translateX(-50%) translateY(0); }

/* Help */
.help {
  width: 100%;
  max-width: 520px;
  margin-top: 14px;
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  overflow: hidden;
}
.help > summary {
  list-style: none;
  cursor: pointer;
  padding: 12px 14px;
  font-size: 14px;
  font-weight: 600;
  color: var(--text-2);
  display: flex;
  align-items: center;
  justify-content: space-between;
}
.help > summary::-webkit-details-marker { display: none; }
.help > summary .chev { color: var(--muted); transition: transform 0.2s ease; }
.help[open] > summary .chev { transform: rotate(180deg); }
.help .body {
  padding: 0 16px 16px;
  color: var(--text-2);
  font-size: 13.5px;
  line-height: 1.65;
}
.help .body h3 {
  color: var(--text);
  font-size: 13px;
  text-transform: uppercase;
  letter-spacing: 0.06em;
  margin: 12px 0 6px;
}
.help .body ul { padding-left: 18px; }
.help .legend { display: grid; grid-template-columns: repeat(auto-fill, minmax(150px, 1fr)); gap: 8px; margin-top: 8px; }
.help .legend .row { display: flex; align-items: center; gap: 9px; }
.help .legend canvas { flex: 0 0 auto; }
.help kbd {
  background: var(--surface-2);
  border: 1px solid var(--border);
  border-bottom-width: 2px;
  border-radius: 5px;
  padding: 1px 6px;
  font-size: 12px;
  font-family: inherit;
  color: var(--text);
}

footer.credit {
  margin-top: 22px;
  color: var(--muted);
  font-size: 12px;
  text-align: center;
}

/* Overlays */
.overlay {
  position: fixed;
  inset: 0;
  display: none;
  align-items: center;
  justify-content: center;
  padding: 20px;
  background: rgba(6, 6, 6, 0.72);
  backdrop-filter: blur(6px);
  -webkit-backdrop-filter: blur(6px);
  z-index: 30;
}
.overlay.show { display: flex; }
.card {
  width: 100%;
  max-width: 420px;
  background: linear-gradient(180deg, #1c1c1a 0%, var(--surface) 100%);
  border: 1px solid var(--border);
  border-radius: 16px;
  box-shadow: var(--shadow);
  padding: 26px 24px;
  text-align: center;
}
.card h2 {
  font-size: 26px;
  font-weight: 800;
  letter-spacing: 0.01em;
  margin-bottom: 6px;
}
.card h2 .a { color: var(--gold); }
.card p { color: var(--text-2); font-size: 14px; line-height: 1.6; margin-bottom: 8px; }
.card .big {
  font-size: 40px;
  font-weight: 800;
  color: var(--gold);
  margin: 10px 0 2px;
}
.card .sub { color: var(--muted); font-size: 13px; margin-bottom: 16px; }
.card .modepick {
  display: flex;
  gap: 8px;
  justify-content: center;
  margin: 16px 0 18px;
}
.card .modepick .opt {
  flex: 1 1 0;
  background: var(--surface-2);
  border: 1px solid var(--border);
  border-radius: 11px;
  padding: 12px 10px;
  cursor: pointer;
  text-align: center;
}
.card .modepick .opt.on { border-color: var(--gold); box-shadow: inset 0 0 0 1px var(--gold); }
.card .modepick .opt .t { font-weight: 700; font-size: 14px; color: var(--text); }
.card .modepick .opt .d { font-size: 11.5px; color: var(--muted); margin-top: 3px; }
.card .actions { display: flex; gap: 10px; justify-content: center; }
.card .actions .btn { padding: 11px 20px; font-size: 14px; }

@media (max-width: 430px) {
  .hud { grid-template-columns: repeat(2, 1fr); }
  .brand .tag { display: none; }
}