:root {
  --bg: #0e1620;
  --bg-2: #16222e;
  --cell: #1d2c3a;
  --cell-given: #24384a;
  --ink: #e8f1f8;
  --ink-dim: #94a9ba;
  --accent: #4fc3a1;
  --accent-2: #7bd7ff;
  --bad: #ff7a7a;
  --sel: #ffd166;
}

* { box-sizing: border-box; }

html, body {
  margin: 0;
  height: 100%;
  background: var(--bg);
  color: var(--ink);
  font-family: ui-sans-serif, system-ui, -apple-system, "Segoe UI", Roboto, Arial, sans-serif;
  -webkit-text-size-adjust: 100%;
  overscroll-behavior: none;
}

#app {
  height: 100dvh;
  display: flex;
  flex-direction: column;
  gap: 4px;
  padding: 6px 8px max(6px, env(safe-area-inset-bottom));
  max-width: 720px;
  margin: 0 auto;
}

.topbar {
  display: flex;
  align-items: baseline;
  gap: 8px;
  font-size: 14px;
  flex: 0 0 auto;
}
.title { font-weight: 700; letter-spacing: 0.2px; }
.title small { font-weight: 400; color: var(--ink-dim); font-size: 11px; margin-left: 4px; }
.spacer { flex: 1 1 auto; }
.hud { font-size: 11px; color: var(--ink-dim); display: flex; gap: 4px; align-items: baseline; }
.hud b { color: var(--ink); font-size: 12px; }
.sep { opacity: 0.5; }

.tabs { display: flex; gap: 4px; flex: 0 0 auto; }
.tab {
  flex: 1 1 0;
  background: var(--bg-2);
  color: var(--ink-dim);
  border: 1px solid transparent;
  border-radius: 8px;
  padding: 4px 0;
  font-size: 11px;
  cursor: pointer;
}
.tab.active { color: var(--ink); border-color: var(--accent); background: #1b3140; }

#status {
  font-size: 11px;
  color: var(--ink-dim);
  line-height: 1.25;
  flex: 0 0 auto;
  min-height: 14px;
}

.stage {
  flex: 1 1 auto;
  min-height: 0;
  display: flex;
  align-items: center;
  justify-content: center;
}

#board {
  display: grid;
  grid-template-columns: 1fr 0.42fr 1fr 0.42fr 1fr;
  grid-template-rows: 1fr 0.42fr 1fr 0.42fr 1fr;
  gap: 3px;
  width: 100%;
  height: 100%;
  max-width: 100%;
  max-height: 100%;
}

.cell {
  appearance: none;
  touch-action: manipulation;
  border: 1px solid #2b3f52;
  background: var(--cell);
  color: var(--ink);
  border-radius: 8px;
  font-size: clamp(14px, 5.2vmin, 30px);
  font-weight: 700;
  display: flex;
  align-items: center;
  justify-content: center;
  padding: 0;
  cursor: pointer;
  line-height: 1;
  min-width: 0;
  min-height: 0;
}
.cell.given {
  background: var(--cell-given);
  border-color: #35506a;
  color: var(--accent-2);
  cursor: default;
}
.cell.sel { border-color: var(--sel); box-shadow: inset 0 0 0 1px var(--sel); }
.cell.hinted { color: var(--accent); }
.cell.bad { border-color: var(--bad); color: var(--bad); }
.cell.empty { color: transparent; }

.op, .eq {
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: clamp(11px, 3.4vmin, 20px);
  color: var(--ink-dim);
  user-select: none;
}
.op.bad { color: var(--bad); font-weight: 700; }
.op.good { color: var(--accent); }
.blank { visibility: hidden; }

.pad {
  flex: 0 0 auto;
  display: grid;
  grid-template-columns: repeat(10, 1fr);
  gap: 3px;
}
.key {
  appearance: none;
  touch-action: manipulation;
  border: 1px solid #2b3f52;
  background: var(--bg-2);
  color: var(--ink);
  border-radius: 8px;
  padding: 6px 0;
  font-size: clamp(12px, 3.6vmin, 18px);
  font-weight: 600;
  cursor: pointer;
  line-height: 1;
}
.key:active { background: #22384c; }
.key.dim { color: #6d8496; }

.actions { display: flex; gap: 4px; flex: 0 0 auto; }
.btn {
  appearance: none;
  touch-action: manipulation;
  flex: 1 1 0;
  border: 1px solid #2b3f52;
  background: var(--bg-2);
  color: var(--ink);
  border-radius: 8px;
  padding: 6px 4px;
  font-size: 12px;
  font-weight: 600;
  cursor: pointer;
}
.btn.primary { background: #1d4b40; border-color: var(--accent); }
.btn:active { transform: translateY(1px); }

#win {
  position: fixed;
  inset: 0;
  background: rgba(6, 12, 18, 0.72);
  display: flex;
  align-items: center;
  justify-content: center;
  padding: 16px;
}
#win.hidden { display: none; }
.win-card {
  background: #14222e;
  border: 1px solid var(--accent);
  border-radius: 12px;
  padding: 14px 16px;
  text-align: center;
  max-width: 320px;
  width: 100%;
}
.win-label { color: var(--accent); font-weight: 700; letter-spacing: 0.4px; text-transform: uppercase; font-size: 12px; }
.win-body { margin: 8px 0 12px; font-size: 13px; color: var(--ink); line-height: 1.4; }

@media (max-height: 300px) {
  .title small { display: none; }
  #status { display: none; }
  #app { gap: 3px; padding: 4px 6px; }
}