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

/* ===== Design tokens ===== */

:root {
  /* Layout */
  --hdr:  60px;
  --ad:   0px;
  --cell: 36px;
  --gap:  2px;
  --r:    4px;

  /* Adaptive monochrome tile — dark theme default: white tile */
  --mono-bg: #e8e8e8;
  --mono-fg: #1a1a1a;

  /* Game tile palette (JS overwrites in newGame) */
  --c0: #e74c3c; --c0f: #fff;
  --c1: #e67e22; --c1f: #fff;
  --c2: #f0c30f; --c2f: #333;
  --c3: #8bc34a; --c3f: #fff;
  --c4: #2ecc71; --c4f: #fff;
  --c5: #1abc9c; --c5f: #fff;
  --c6: #3498db; --c6f: #fff;
  --c7: #5c6bc0; --c7f: #fff;
  --c8: #9b59b6; --c8f: #fff;
  --c9: #e91e8c; --c9f: #fff;

  /* UI tokens — dark theme (default) */
  --page-bg:     #0d0d1a;
  --surface-bg:  #16162a;
  --sunken-bg:   #0a0a18;
  --cell-bg:     #111128;
  --cell-hover:  #1e1e44;
  --ui-bg:       #2d2d4e;
  --ui-hover:    #3d3d5e;
  --ghost-hover: #1e1e3a;
  --brd-soft:    #2d2d4e;
  --brd-faint:   #1a1a36;
  --brd-mid:     #3a3a66;
  --brd-hard:    #444466;
  --txt-hi:      #ffffff;
  --txt-mid:     #cccccc;
  --txt-lo:      #888888;
  --txt-hint:    #6666aa;
  --txt-dim:     #aaaaaa;
  --track-bg:    #333355;
  --board-glow:  rgba(129, 140, 248, 0.10);
}

/* Light theme overrides */
:root[data-theme="light"] {
  --page-bg:     #eef0fa;
  --surface-bg:  #f8f9ff;
  --sunken-bg:   #e2e6f4;
  --cell-bg:     #d2d6ec;
  --cell-hover:  #c6cadd;
  --ui-bg:       #e2e6f2;
  --ui-hover:    #d4d8e8;
  --ghost-hover: #eaecf6;
  --brd-soft:    #cdd0e6;
  --brd-faint:   #d6daea;
  --brd-mid:     #b0b4cc;
  --brd-hard:    #b6bacc;
  --txt-hi:      #1a1a2e;
  --txt-mid:     #3a3a58;
  --txt-lo:      #5a5a78;
  --txt-hint:    #6666aa;
  --txt-dim:     #7a7a98;
  --track-bg:    #c0c4da;
  --board-glow:  rgba(100, 110, 180, 0.18);
  --mono-bg:     #1a1a1a;
  --mono-fg:     #e8e8e8;
}

body {
  font-family: system-ui, -apple-system, sans-serif;
  background: var(--page-bg);
  color: var(--txt-hi);
  height: 100dvh;
  display: flex;
  flex-direction: column;
  overflow: hidden;
}

/* ---- Header ---- */

.game-header {
  height: var(--hdr);
  display: flex;
  align-items: center;
  gap: 12px;
  padding: 0 16px;
  background: var(--surface-bg);
  border-bottom: 1px solid var(--brd-soft);
  flex-shrink: 0;
}

.game-title {
  font-size: 1.1rem;
  font-weight: 800;
  letter-spacing: 0.05em;
  background: linear-gradient(135deg, #818cf8, #a78bfa);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
  white-space: nowrap;
}

.game-stats {
  display: flex;
  gap: 20px;
  margin-left: auto;
}

.stat {
  display: flex;
  flex-direction: column;
  align-items: center;
}

.stat-label {
  font-size: 0.6rem;
  letter-spacing: 0.08em;
  color: var(--txt-hint);
  text-transform: uppercase;
}

.stat-value {
  font-size: 1.2rem;
  font-weight: 700;
  font-variant-numeric: tabular-nums;
  line-height: 1.2;
  color: var(--txt-hi);
}

#timer-stat .stat-value                       { color: #4ade80; }
#timer-stat[data-urgency="warn"] .stat-value   { color: #f59e0b; }
#timer-stat[data-urgency="danger"] .stat-value { color: #ef4444; }

.header-actions {
  display: flex;
  align-items: center;
  gap: 8px;
}

/* ---- Buttons ---- */

.btn {
  padding: 6px 14px;
  border: none;
  border-radius: 6px;
  cursor: pointer;
  font-size: 0.8rem;
  font-weight: 600;
  transition: opacity 0.15s, transform 0.1s;
}
.btn:active { transform: scale(0.95); }

.btn-sm {
  background: var(--ui-bg);
  color: var(--txt-mid);
}
.btn-sm:hover { background: var(--ui-hover); color: var(--txt-hi); }

.btn-primary {
  background: linear-gradient(135deg, #818cf8, #a78bfa);
  color: #fff;
}
.btn-primary:hover { opacity: 0.88; }

.btn-ghost {
  background: transparent;
  color: var(--txt-lo);
  border: 1px solid var(--brd-hard);
}
.btn-ghost:hover { background: var(--ghost-hover); color: var(--txt-mid); }

.btn-icon {
  background: none;
  border: 1px solid var(--brd-hard);
  color: var(--txt-dim);
  width: 32px;
  height: 32px;
  border-radius: 6px;
  cursor: pointer;
  font-size: 1rem;
  display: flex;
  align-items: center;
  justify-content: center;
  transition: background 0.15s, color 0.15s;
}
.btn-icon:hover { background: var(--ui-bg); color: var(--txt-hi); }
a.btn-icon      { text-decoration: none; }

/* ---- Main ---- */

.game-main {
  flex: 1;
  display: flex;
  align-items: center;
  justify-content: center;
  overflow: hidden;
}

/* ---- Board ---- */

.board {
  display: grid;
  grid-template-columns: repeat(15, var(--cell));
  grid-template-rows: repeat(23, var(--cell));
  gap: var(--gap);
  background: var(--sunken-bg);
  padding: var(--gap);
  border-radius: 8px;
  box-shadow: 0 0 40px var(--board-glow);
}

/* ---- Cells ---- */

.cell {
  width: var(--cell);
  height: var(--cell);
  border-radius: var(--r);
  background: var(--cell-bg);
  border: 1px solid var(--brd-faint);
  cursor: pointer;
  transition: background 0.12s, border-color 0.12s;
}

.cell:hover {
  background: var(--cell-hover);
  border-color: var(--brd-mid);
}

.cell.has-tile {
  background: transparent;
  border: none;
  cursor: default;
}

/* ---- Tiles ---- */

.tile {
  width: 100%;
  height: 100%;
  border-radius: var(--r);
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: calc(var(--cell) * 0.5);
  font-weight: 700;
  line-height: 1;
  user-select: none;
  opacity: 1;
  scale: 1;
  box-shadow: inset 0 -3px 0 rgba(0,0,0,0.25);
  transition: opacity 0.22s ease-out, scale 0.22s ease-out;
}

/* タイル出現アニメーション */
@starting-style {
  .tile {
    opacity: 0;
    scale: 0.4;
  }
}

.tile.removing {
  opacity: 0;
  scale: 0.15;
  transition-duration: 0.18s;
}

.tile[data-color="0"] { background: var(--c0); color: var(--c0f); }
.tile[data-color="1"] { background: var(--c1); color: var(--c1f); }
.tile[data-color="2"] { background: var(--c2); color: var(--c2f); }
.tile[data-color="3"] { background: var(--c3); color: var(--c3f); }
.tile[data-color="4"] { background: var(--c4); color: var(--c4f); }
.tile[data-color="5"] { background: var(--c5); color: var(--c5f); }
.tile[data-color="6"] { background: var(--c6); color: var(--c6f); }
.tile[data-color="7"] { background: var(--c7); color: var(--c7f); }
.tile[data-color="8"] { background: var(--c8); color: var(--c8f); }
.tile[data-color="9"] { background: var(--c9); color: var(--c9f); }

/* ---- Dialog ---- */

dialog {
  background: var(--surface-bg);
  color: var(--txt-hi);
  border: 1px solid var(--brd-soft);
  border-radius: 16px;
  padding: 0;
  max-width: 340px;
  width: calc(100vw - 32px);
  margin: auto;
  box-shadow: 0 24px 64px rgba(0, 0, 0, 0.55);

  opacity: 0;
  translate: 0 -12px;
  scale: 0.97;
  transition:
    opacity 0.22s ease-out,
    translate 0.22s ease-out,
    scale 0.22s ease-out,
    overlay 0.22s allow-discrete,
    display 0.22s allow-discrete;
}

dialog[open] {
  opacity: 1;
  translate: 0;
  scale: 1;
}

@starting-style {
  dialog[open] {
    opacity: 0;
    translate: 0 -12px;
    scale: 0.97;
  }
  dialog[open]::backdrop {
    background: rgba(0, 0, 0, 0);
    backdrop-filter: blur(0);
  }
}

dialog::backdrop {
  background: rgba(0, 0, 0, 0);
  backdrop-filter: blur(0);
  transition:
    background 0.22s,
    backdrop-filter 0.22s,
    overlay 0.22s allow-discrete,
    display 0.22s allow-discrete;
}

dialog[open]::backdrop {
  background: rgba(0, 0, 0, 0.55);
  backdrop-filter: blur(4px);
}

.dialog-inner {
  padding: 24px;
  display: flex;
  flex-direction: column;
  gap: 20px;
}

.dialog-inner h2 {
  font-size: 1.2rem;
  font-weight: 700;
}

#dialog-gameover .dialog-inner h2 {
  text-align: center;
}

.field {
  display: flex;
  flex-direction: column;
  gap: 6px;
}

.field label {
  font-size: 0.8rem;
  color: var(--txt-lo);
}

/* ---- Range slider ---- */

.range-row {
  display: flex;
  align-items: center;
  gap: 12px;
}

.range-val {
  font-size: 1rem;
  font-weight: 700;
  color: #818cf8;
  min-width: 38px;
  text-align: right;
  font-variant-numeric: tabular-nums;
  flex-shrink: 0;
}

input[type="range"] {
  flex: 1;
  -webkit-appearance: none;
  appearance: none;
  height: 6px;
  border-radius: 3px;
  background: var(--track-bg);
  outline: none;
  cursor: pointer;
}

input[type="range"]::-webkit-slider-thumb {
  -webkit-appearance: none;
  appearance: none;
  width: 22px;
  height: 22px;
  border-radius: 50%;
  background: #818cf8;
  cursor: pointer;
  transition: background 0.15s, transform 0.1s;
}

input[type="range"]::-webkit-slider-thumb:hover {
  background: #a78bfa;
  transform: scale(1.15);
}

input[type="range"]::-moz-range-thumb {
  width: 22px;
  height: 22px;
  border: none;
  border-radius: 50%;
  background: #818cf8;
  cursor: pointer;
}

input[type="range"]:focus-visible::-webkit-slider-thumb {
  background: #a78bfa;
  box-shadow: 0 0 0 3px rgba(129, 140, 248, 0.35);
}

.dialog-actions {
  display: flex;
  flex-direction: column;
  gap: 8px;
}

/* ---- Result ---- */

.result {
  text-align: center;
}

.result-score {
  font-size: 3rem;
  font-weight: 800;
  line-height: 1;
  color: #818cf8;
  margin-bottom: 8px;
}

.result-unit {
  font-size: 1.2rem;
  color: var(--txt-lo);
  margin-left: 4px;
}

#result-message {
  font-size: 0.875rem;
  color: var(--txt-lo);
  margin-top: 4px;
}

/* ---- Select ---- */

.field select {
  background: var(--page-bg);
  border: 1px solid var(--track-bg);
  border-radius: 8px;
  color: var(--txt-hi);
  padding: 8px 12px;
  font-size: 1rem;
  outline: none;
  width: 100%;
  transition: border-color 0.15s;
  cursor: pointer;
}
.field select:focus { border-color: #818cf8; }

/* ---- Checkbox row ---- */

.field-row {
  flex-direction: row;
  align-items: center;
  gap: 10px;
}
.field-row input[type="checkbox"] {
  width: 18px;
  height: 18px;
  accent-color: #818cf8;
  cursor: pointer;
  flex-shrink: 0;
}
.field-row label {
  font-size: 0.875rem;
  color: var(--txt-mid);
  cursor: pointer;
  line-height: 1.4;
}

.seg-toggle {
  display: flex;
  border: 1px solid var(--border);
  border-radius: 8px;
  overflow: hidden;
}

.seg-btn {
  flex: 1;
  padding: 7px 0;
  font-size: 0.875rem;
  font-weight: 600;
  background: transparent;
  color: var(--txt-mid);
  border: none;
  cursor: pointer;
  transition: background 0.15s, color 0.15s;
}

.seg-btn + .seg-btn {
  border-left: 1px solid var(--border);
}

.seg-btn--active {
  background: #818cf8;
  color: #fff;
}

/* body.large-tiles は JS が --cell と grid を設定するので CSS 計算は不要 */

/* ---- 広告バナー（モバイルのみ表示） ---- */

.ad-banner {
  display: none;
  height: var(--ad);
  background: var(--sunken-bg);
  border-top: 1px solid var(--brd-faint);
  flex-shrink: 0;
}

.ad-placeholder {
  height: 100%;
  display: flex;
  align-items: center;
  justify-content: center;
  color: var(--track-bg);
  font-size: 0.75rem;
  letter-spacing: 0.1em;
  border: 1px dashed var(--ghost-hover);
  margin: 4px 16px;
  border-radius: 4px;
}

@media (max-width: 768px) {
  :root {
    --ad: 60px;
  }

  .ad-banner {
    display: block;
  }
}

/* ---- TOP ペイン ---- */

#top-pane {
  position: fixed;
  inset: 0;
  z-index: 100;
  cursor: pointer;
  display: flex;
  align-items: center;
  justify-content: center;
  transition: opacity 0.5s ease;
  -webkit-tap-highlight-color: transparent;
}

#top-pane.top-pane--out {
  opacity: 0;
  pointer-events: none;
}

.top-bg {
  position: absolute;
  inset: 0;
}

.top-base {
  position: absolute;
  top: 0;
  left: 50%;
  transform: translateX(-50%);
  width: auto;
  height: auto;
  display: block;
}

.top-content {
  position: relative;
  z-index: 1;
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 48px;
  padding: 16px;
  width: min(340px, 94vw);
}

.top-rule-card {
  background: rgba(10, 10, 26, 0.82);
  backdrop-filter: blur(6px);
  -webkit-backdrop-filter: blur(6px);
  border: 1px solid rgba(124, 106, 247, 0.35);
  border-radius: 16px;
  padding: 14px 14px 10px;
  width: 100%;
}

.top-rule-title {
  text-align: center;
  color: #c4b5ff;
  font-size: 13px;
  font-weight: 700;
  margin-bottom: 10px;
  letter-spacing: 0.02em;
}

.top-rule-card svg {
  width: 100%;
  height: auto;
  display: block;
}

.top-play {
  font-size: clamp(3.5rem, 18vw, 7rem);
  font-weight: 900;
  color: #ffffff;
  letter-spacing: 0.06em;
  user-select: none;
  text-shadow:
    0 2px 24px rgba(0, 0, 0, 0.95),
    0 0  80px rgba(124, 106, 247, 0.7),
    0 0 160px rgba(124, 106, 247, 0.35);
}