/* ── Sudoku Styles ─────────────────────────────────────────────── */
:root {
  --bg: #0f0f1a;
  --bg-2: #1a1a2e;
  --ink: #0a0a1a;
  --cream: #e8e6f0;
  --dim: #8888aa;
  --accent: #7c6df0;
  --accent-glow: rgba(124,109,240,0.3);
  --gold: #ffe46b;
  --green: #7cf0c0;
  --rose: #ff5d5d;
  --cell-bg: #1a1a2e;
  --cell-bg-hover: #22223e;
  --cell-bg-selected: #2e2a5a;
  --cell-bg-peer: #20203a;
  --cell-bg-same-num: #2a2050;
  --grid-line: rgba(120,120,200,0.15);
  --grid-line-bold: rgba(200,200,255,0.45);
}

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

html, body { height: 100%; }

body {
  min-height: 100vh;
  min-height: 100dvh;
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: clamp(6px, 1.2vh, 14px);
  padding: clamp(8px, 1.5vh, 18px) 10px;
  background-color: var(--bg);
  background-image:
    radial-gradient(circle at 40% 30%, rgba(124,109,240,0.07) 0%, transparent 50%),
    radial-gradient(circle at 60% 70%, rgba(124,240,192,0.04) 0%, transparent 50%);
  font-family: 'Press Start 2P', monospace;
  color: var(--cream);
  user-select: none;
  -webkit-user-select: none;
  -webkit-tap-highlight-color: transparent;
  overflow-x: hidden;
}

/* ── HUD ─────────────────────────────────────────────────────── */
.hud {
  width: 100%;
  max-width: 480px;
  display: flex;
  justify-content: space-between;
  align-items: center;
  padding: 0 4px;
  z-index: 5;
}

.hud-mistakes {
  display: flex;
  align-items: center;
  gap: 6px;
  font-size: 0.5em;
  color: var(--dim);
}

.mistake-dot {
  width: 12px;
  height: 12px;
  border-radius: 50%;
  background: rgba(255,93,93,0.2);
  border: 1px solid rgba(255,93,93,0.3);
  transition: background 0.3s, border-color 0.3s, transform 0.3s;
}

.mistake-dot.used {
  background: var(--rose);
  border-color: var(--rose);
  box-shadow: 0 0 8px rgba(255,93,93,0.5);
  animation: mistakePop 0.4s ease-out;
}

@keyframes mistakePop {
  0% { transform: scale(0.5); }
  50% { transform: scale(1.3); }
  100% { transform: scale(1); }
}

.hud-label {
  font-size: 0.45em;
  letter-spacing: 0.2em;
  color: var(--dim);
}

/* ── Game Area ───────────────────────────────────────────────── */
#game-area {
  width: 100%;
  max-width: 480px;
  flex: 1 1 auto;
  min-height: 0;
  display: flex;
  flex-direction: column;
  gap: 10px;
}

/* ── Sudoku HUD (combo / progress / timer) ───────────────────── */
.sudoku-hud {
  display: flex;
  gap: 8px;
  align-items: stretch;
  font-size: 0.42em;
}

.hud-chip {
  flex: 1;
  background: rgba(26,26,46,0.7);
  border: 1px solid rgba(124,109,240,0.25);
  border-radius: 8px;
  padding: 6px 8px;
  display: flex;
  flex-direction: column;
  gap: 3px;
  align-items: center;
  justify-content: center;
  transition: border-color 0.25s, box-shadow 0.25s, transform 0.15s;
}

.hud-chip-label {
  font-size: 0.8em;
  letter-spacing: 0.15em;
  color: var(--dim);
}

.hud-chip-val {
  font-size: 1.4em;
  color: var(--cream);
}

.hud-combo {
  position: relative;
  overflow: hidden;
}

.hud-combo.hot {
  border-color: var(--gold);
  box-shadow: 0 0 12px rgba(255,228,107,0.3);
}

.hud-combo.fire {
  border-color: var(--rose);
  box-shadow: 0 0 18px rgba(255,93,93,0.4);
  animation: comboFire 0.6s ease-in-out infinite alternate;
}

@keyframes comboFire {
  from { box-shadow: 0 0 12px rgba(255,93,93,0.3); }
  to { box-shadow: 0 0 22px rgba(255,228,107,0.5); }
}

.hud-combo-flame {
  position: absolute;
  top: 2px;
  right: 4px;
  font-size: 0.9em;
  filter: drop-shadow(0 0 4px var(--gold));
}

.hud-progress {
  flex: 1.5;
}

.hud-progress-bar {
  width: 100%;
  height: 8px;
  background: rgba(124,109,240,0.15);
  border-radius: 4px;
  overflow: hidden;
  margin-top: 2px;
}

.hud-progress-fill {
  height: 100%;
  width: 0%;
  background: linear-gradient(90deg, var(--accent), var(--green));
  border-radius: 4px;
  transition: width 0.4s cubic-bezier(0.34, 1.56, 0.64, 1);
  box-shadow: 0 0 8px rgba(124,240,192,0.4);
}

/* ── Board ───────────────────────────────────────────────────── */
.sudoku-board-wrap {
  display: flex;
  justify-content: center;
}

.sudoku-board {
  display: grid;
  grid-template-columns: repeat(9, 1fr);
  gap: 0;
  background: var(--grid-line-bold);
  border: 3px solid var(--grid-line-bold);
  border-radius: 8px;
  overflow: hidden;
  width: min(92vw, 420px);
  aspect-ratio: 1 / 1;
}

.sudoku-cell {
  font-family: 'Press Start 2P', monospace;
  font-size: clamp(0.6em, 3.5vw, 1.1em);
  color: var(--cream);
  background: var(--cell-bg);
  border: 1px solid var(--grid-line);
  cursor: pointer;
  appearance: none;
  -webkit-appearance: none;
  text-align: center;
  display: flex;
  align-items: center;
  justify-content: center;
  position: relative;
  transition: background 0.12s, color 0.12s, transform 0.12s, box-shadow 0.15s;
  padding: 0;
  line-height: 1;
}

.sudoku-cell:hover { background: var(--cell-bg-hover); }
.sudoku-cell:active { transform: scale(0.95); }

.sudoku-cell.peer { background: var(--cell-bg-peer); }
.sudoku-cell.same-num {
  background: var(--cell-bg-same-num);
  color: var(--gold);
}
.sudoku-cell.selected {
  background: var(--cell-bg-selected);
  box-shadow: inset 0 0 0 2px var(--accent), 0 0 12px var(--accent-glow);
  z-index: 2;
}

.sudoku-cell.given { color: var(--cream); font-weight: bold; }
.sudoku-cell.placed { color: var(--green); }
.sudoku-cell.wrong { color: var(--rose); }

.sudoku-cell.border-l-bold { border-left: 2px solid var(--grid-line-bold); }
.sudoku-cell.border-t-bold { border-top: 2px solid var(--grid-line-bold); }

/* Notes mini-grid */
.notes-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  grid-template-rows: repeat(3, 1fr);
  width: 100%;
  height: 100%;
  padding: 2px;
  gap: 0;
}

.note {
  font-size: 0.32em;
  color: transparent;
  display: flex;
  align-items: center;
  justify-content: center;
  line-height: 1;
}

.note.on { color: var(--dim); }

/* ── Animations ──────────────────────────────────────────────── */
@keyframes stampIn {
  0% { transform: scale(0.3); opacity: 0; }
  60% { transform: scale(1.25); opacity: 1; }
  100% { transform: scale(1); opacity: 1; }
}

.sudoku-cell.stamp-in {
  animation: stampIn 0.28s cubic-bezier(0.34, 1.56, 0.64, 1);
}

@keyframes cellShake {
  0%, 100% { transform: translateX(0); }
  15% { transform: translateX(-5px); }
  30% { transform: translateX(5px); }
  45% { transform: translateX(-3px); }
  60% { transform: translateX(3px); }
  75% { transform: translateX(-2px); }
  90% { transform: translateX(2px); }
}

.sudoku-cell.shake { animation: cellShake 0.4s ease-in-out; }

.sudoku-cell.wrong-flash {
  background: rgba(255,93,93,0.3) !important;
  box-shadow: 0 0 14px rgba(255,93,93,0.5);
}

@keyframes unitFlash {
  0% { background: var(--cell-bg); }
  35% { background: rgba(124,240,192,0.35); box-shadow: 0 0 12px rgba(124,240,192,0.5); }
  100% { background: var(--cell-bg); }
}

.sudoku-cell.unit-flash { animation: unitFlash 0.5s ease-out; }

@keyframes hintGlow {
  0% { box-shadow: 0 0 0 0 rgba(255,228,107,0.7); }
  50% { box-shadow: 0 0 20px 8px rgba(255,228,107,0.6); background: rgba(255,228,107,0.15); }
  100% { box-shadow: 0 0 0 0 rgba(255,228,107,0); }
}

.sudoku-cell.hint-glow { animation: hintGlow 0.8s ease-out; }

/* ── Number Pad ──────────────────────────────────────────────── */
.sudoku-pad {
  display: grid;
  grid-template-columns: repeat(9, 1fr);
  gap: 4px;
}

.pad-num {
  font-family: 'Press Start 2P', monospace;
  font-size: clamp(0.5em, 2.4vw, 0.8em);
  color: var(--cream);
  background: rgba(124,109,240,0.12);
  border: 1px solid rgba(124,109,240,0.3);
  border-radius: 8px;
  padding: 10px 0;
  cursor: pointer;
  appearance: none;
  -webkit-appearance: none;
  text-align: center;
  position: relative;
  transition: background 0.12s, border-color 0.12s, transform 0.08s, opacity 0.15s;
}

.pad-num:hover:not(.done) {
  background: rgba(124,109,240,0.3);
  border-color: rgba(124,109,240,0.6);
  transform: translateY(-2px);
}

.pad-num:active:not(.done) { transform: translateY(0) scale(0.95); }

.pad-num.done {
  opacity: 0.3;
  cursor: default;
  text-decoration: line-through;
}

.pad-num.count-low {
  border-color: rgba(255,228,107,0.5);
  color: var(--gold);
}

.pad-remaining {
  font-size: 0.5em;
  vertical-align: sub;
  color: var(--dim);
  margin-left: 1px;
}

/* ── Tools ───────────────────────────────────────────────────── */
.sudoku-tools {
  display: flex;
  gap: 6px;
  flex-wrap: wrap;
  justify-content: center;
}

.pad-tool {
  font-family: 'Press Start 2P', monospace;
  font-size: 0.4em;
  color: var(--cream);
  background: rgba(124,109,240,0.1);
  border: 1px solid rgba(124,109,240,0.25);
  border-radius: 8px;
  padding: 8px 10px;
  cursor: pointer;
  appearance: none;
  -webkit-appearance: none;
  transition: background 0.12s, border-color 0.12s, transform 0.08s, opacity 0.15s;
  white-space: nowrap;
}

.pad-tool:hover:not(:disabled) {
  background: rgba(124,109,240,0.25);
  border-color: rgba(124,109,240,0.5);
}

.pad-tool:active:not(:disabled) { transform: translateY(1px); }

.pad-tool:disabled { opacity: 0.35; cursor: default; }

.pad-tool.active {
  background: rgba(124,240,192,0.2);
  border-color: rgba(124,240,192,0.6);
  color: var(--green);
  box-shadow: 0 0 10px rgba(124,240,192,0.3);
}

/* ── Footer ──────────────────────────────────────────────────── */
.footer {
  display: flex;
  align-items: center;
  gap: 12px;
  font-size: 0.5em;
  color: var(--dim);
  z-index: 5;
}

.seed-display { letter-spacing: 0.05em; }

/* ── Buttons (shared) ────────────────────────────────────────── */
.btn {
  font-family: 'Press Start 2P', monospace;
  font-size: 0.45em;
  color: var(--cream);
  background: rgba(124,109,240,0.15);
  border: 1px solid rgba(124,109,240,0.3);
  border-radius: 8px;
  padding: 8px 12px;
  cursor: pointer;
  appearance: none;
  -webkit-appearance: none;
  text-decoration: none;
  transition: background 0.15s, border-color 0.15s, transform 0.08s, opacity 0.15s;
}

.btn:hover { background: rgba(124,109,240,0.3); border-color: rgba(124,109,240,0.5); }
.btn:active { transform: translateY(1px); }

/* ── Toast ───────────────────────────────────────────────────── */
.toast {
  position: fixed;
  bottom: 80px;
  left: 50%;
  transform: translateX(-50%) translateY(20px);
  background: rgba(26,26,46,0.95);
  border: 1px solid var(--accent);
  color: var(--cream);
  padding: 10px 18px;
  border-radius: 8px;
  font-size: 0.5em;
  opacity: 0;
  pointer-events: none;
  transition: opacity 0.25s, transform 0.25s;
  z-index: 200;
}

.toast.visible {
  opacity: 1;
  transform: translateX(-50%) translateY(0);
}

/* ── Overlays ────────────────────────────────────────────────── */
.overlay {
  position: fixed;
  inset: 0;
  background: rgba(10,10,26,0.85);
  display: none;
  align-items: center;
  justify-content: center;
  z-index: 100;
  padding: 16px;
  backdrop-filter: blur(4px);
  -webkit-backdrop-filter: blur(4px);
}

.overlay.visible { display: flex; }

.panel {
  background: var(--bg-2);
  border: 2px solid var(--accent);
  border-radius: 14px;
  padding: 22px 20px;
  max-width: 380px;
  width: 100%;
  text-align: center;
  box-shadow: 0 0 40px var(--accent-glow);
  animation: panelIn 0.3s ease-out;
}

@keyframes panelIn {
  from { transform: scale(0.85); opacity: 0; }
  to { transform: scale(1); opacity: 1; }
}

.panel-title {
  font-size: 1em;
  letter-spacing: 0.15em;
  color: var(--gold);
  margin-bottom: 10px;
  text-shadow: 0 0 10px rgba(255,228,107,0.4);
}

.go-msg {
  font-size: 0.55em;
  color: var(--green);
  margin-bottom: 14px;
  min-height: 1.2em;
}

.go-stats {
  display: flex;
  flex-direction: column;
  gap: 6px;
  margin-bottom: 16px;
  text-align: left;
}

.go-row {
  display: flex;
  justify-content: space-between;
  font-size: 0.4em;
  padding: 5px 8px;
  background: rgba(124,109,240,0.08);
  border-radius: 6px;
}

.go-label { color: var(--dim); }
.go-val { color: var(--cream); }

.go-actions {
  display: flex;
  flex-wrap: wrap;
  gap: 6px;
  justify-content: center;
}

.go-actions .btn { font-size: 0.42em; padding: 9px 11px; }

/* ── Start Screen ────────────────────────────────────────────── */
.start-overlay {
  display: flex;
  background: var(--bg);
  z-index: 90;
  cursor: pointer;
}

.start-content {
  text-align: center;
  animation: startIn 0.6s ease-out;
}

@keyframes startIn {
  from { opacity: 0; transform: translateY(20px); }
  to { opacity: 1; transform: translateY(0); }
}

.start-title {
  font-size: clamp(1.4em, 8vw, 2.6em);
  letter-spacing: 0.15em;
  color: var(--cream);
  text-shadow:
    0 0 20px var(--accent-glow),
    3px 3px 0 var(--accent);
  margin-bottom: 14px;
}

.start-sub {
  font-size: 0.6em;
  color: var(--dim);
  margin-bottom: 24px;
}

.start-bar {
  width: 200px;
  height: 4px;
  background: rgba(124,109,240,0.2);
  border-radius: 2px;
  margin: 0 auto 24px;
  overflow: hidden;
}

.start-bar-fill {
  height: 100%;
  width: 100%;
  background: linear-gradient(90deg, var(--accent), var(--green));
  animation: barPulse 2s ease-in-out infinite;
}

@keyframes barPulse {
  0%, 100% { opacity: 0.5; transform: scaleX(0.6); }
  50% { opacity: 1; transform: scaleX(1); }
}

.diff-selector {
  display: flex;
  gap: 6px;
  margin-bottom: 24px;
  flex-wrap: wrap;
  justify-content: center;
}

.diff-btn {
  font-family: 'Press Start 2P', monospace;
  font-size: 0.45em;
  color: var(--dim);
  background: rgba(124,109,240,0.1);
  border: 1px solid rgba(124,109,240,0.25);
  border-radius: 8px;
  padding: 8px 10px;
  cursor: pointer;
  appearance: none;
  -webkit-appearance: none;
  transition: all 0.15s;
}

.diff-btn:hover { color: var(--cream); border-color: rgba(124,109,240,0.5); }

.diff-btn.active {
  color: var(--green);
  background: rgba(124,240,192,0.15);
  border-color: rgba(124,240,192,0.6);
  box-shadow: 0 0 12px rgba(124,240,192,0.3);
}

.start-prompt {
  font-size: 0.55em;
  color: var(--gold);
  animation: promptBlink 1.2s ease-in-out infinite;
}

@keyframes promptBlink {
  0%, 100% { opacity: 0.4; }
  50% { opacity: 1; }
}

.start-overlay.gone {
  animation: startOut 0.4s ease-in forwards;
}

@keyframes startOut {
  to { opacity: 0; transform: scale(1.1); }
}

/* ── Tutorial ────────────────────────────────────────────────── */
.tut-panel {
  max-width: 420px;
  max-height: 88vh;
  overflow-y: auto;
  position: relative;
}

.tut-close {
  position: absolute;
  top: 10px;
  right: 12px;
  background: none;
  border: none;
  color: var(--dim);
  font-size: 1.2em;
  cursor: pointer;
  line-height: 1;
}

.tut-cards {
  display: flex;
  flex-direction: column;
  gap: 12px;
  margin: 16px 0;
  text-align: left;
}

.tut-card {
  background: rgba(124,109,240,0.08);
  border: 1px solid rgba(124,109,240,0.2);
  border-radius: 10px;
  padding: 12px;
  display: flex;
  gap: 12px;
  align-items: flex-start;
}

.tut-icon { font-size: 1.4em; }

.tut-heading {
  font-size: 0.5em;
  color: var(--gold);
  margin-bottom: 6px;
}

.tut-body {
  font-family: system-ui, -apple-system, sans-serif;
  font-size: 0.62rem;
  line-height: 1.5;
  color: var(--cream);
}

.tut-close-btn {
  font-family: 'Press Start 2P', monospace;
  font-size: 0.5em;
  color: var(--green);
  background: rgba(124,240,192,0.15);
  border: 1px solid rgba(124,240,192,0.5);
  border-radius: 8px;
  padding: 10px 20px;
  cursor: pointer;
  margin-top: 8px;
  transition: all 0.15s;
}

.tut-close-btn:hover { background: rgba(124,240,192,0.3); }

/* ── Responsive ──────────────────────────────────────────────── */
@media (max-width: 380px) {
  .hud-chip { padding: 5px 4px; }
  .hud-chip-label { font-size: 0.7em; }
  .hud-chip-val { font-size: 1.2em; }
  .pad-tool { font-size: 0.36em; padding: 7px 8px; }
  .sudoku-tools { gap: 4px; }
}

@media (max-height: 680px) {
  .sudoku-hud { font-size: 0.38em; }
  .hud-chip { padding: 4px 6px; }
  .sudoku-board { width: min(85vw, 360px); }
}