:root {
  --bg-top: #e8eef7;
  --bg-bottom: #d4dfec;
  --card-bg: rgba(251, 253, 255, 0.9);
  --card-border: rgba(255, 255, 255, 0.72);
  --surface: rgba(255, 255, 255, 0.72);
  --surface-strong: rgba(255, 255, 255, 0.92);
  --surface-soft: rgba(255, 255, 255, 0.58);
  --text-main: #18202c;
  --text-muted: #627081;
  --board-frame-top: #303a48;
  --board-frame-bottom: #19232d;
  --cell-light: #fcfeff;
  --cell-dark: #101821;
  --cell-line: rgba(12, 19, 29, 0.18);
  --accent: #256de0;
  --accent-strong: #174f9e;
  --accent-soft: rgba(37, 109, 224, 0.12);
  --success-bg: rgba(88, 181, 122, 0.16);
  --success-text: #1b6338;
  --daily-soft: rgba(255, 199, 86, 0.18);
  --daily-text: #8d640d;
  --shadow-soft: 0 32px 80px rgba(26, 38, 55, 0.18);
  --shadow-button: 0 14px 28px rgba(37, 109, 224, 0.2);
}

* {
  box-sizing: border-box;
}

html {
  -webkit-tap-highlight-color: transparent;
}

body {
  margin: 0;
  min-height: 100vh;
  font-family: "Noto Sans JP", "Hiragino Sans", "Yu Gothic UI", sans-serif;
  color: var(--text-main);
  overscroll-behavior-y: contain;
  background:
    radial-gradient(circle at top, rgba(255, 255, 255, 0.84), transparent 32%),
    linear-gradient(160deg, var(--bg-top), var(--bg-bottom));
}

body::before {
  content: "";
  position: fixed;
  inset: 0;
  background:
    linear-gradient(rgba(255, 255, 255, 0.18) 1px, transparent 1px),
    linear-gradient(90deg, rgba(255, 255, 255, 0.18) 1px, transparent 1px);
  background-size: 34px 34px;
  mask-image: linear-gradient(to bottom, rgba(0, 0, 0, 0.34), transparent 92%);
  pointer-events: none;
}

.app-shell {
  min-height: 100vh;
  display: grid;
  place-items: center;
  padding:
    max(20px, env(safe-area-inset-top))
    max(16px, env(safe-area-inset-right))
    max(24px, env(safe-area-inset-bottom))
    max(16px, env(safe-area-inset-left));
}

.game-card {
  width: min(100%, 980px);
  padding: clamp(20px, 4vw, 36px);
  border: 1px solid var(--card-border);
  border-radius: 30px;
  background: var(--card-bg);
  box-shadow: var(--shadow-soft);
  backdrop-filter: blur(20px);
}

.hero,
.hero-main,
.control-group,
.overview-item,
.selection-card-body,
.status-tile {
  display: grid;
}

.hero {
  gap: 18px;
}

.hero-main {
  gap: 14px;
}

.hero-topline {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 12px;
}

.lang-switcher {
  display: inline-grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 6px;
  min-width: 170px;
}

.eyebrow,
.section-kicker,
.notice-kicker,
.difficulty-pill,
.control-label {
  margin: 0;
  color: var(--accent-strong);
  font-size: 0.78rem;
  font-weight: 700;
  letter-spacing: 0.12em;
  text-transform: uppercase;
}

h1,
.section-title,
.notice-title,
.difficulty-title {
  margin: 0;
}

h1 {
  font-size: clamp(2rem, 4.8vw, 3rem);
  line-height: 1.04;
}

.brand-heading,
.footer-brand {
  display: inline-flex;
  align-items: center;
}

.brand-logo {
  display: block;
  width: min(100%, 320px);
  height: auto;
}

.footer-logo {
  display: block;
  width: clamp(124px, 18vw, 180px);
  height: auto;
}

.description,
.selection-note,
.notice-text,
.status-subtext,
.selection-card-meta,
.difficulty-text,
.overview-label,
.control-help,
.records-copy,
.achievement-meta,
.metric-label,
.metric-note,
.result-copy-preview {
  color: var(--text-muted);
}

.description,
.selection-note,
.notice-text,
.control-help {
  line-height: 1.72;
}

.overview-panel,
.control-panel,
.home-panel,
.status-tile,
.notice-panel,
.difficulty-block,
.selection-card,
.records-section,
.metric-card,
.achievement-card {
  border: 1px solid rgba(18, 25, 36, 0.08);
}

.overview-panel {
  display: grid;
  grid-template-columns: repeat(3, minmax(0, 1fr));
  gap: 12px;
  padding: 14px;
  border-radius: 22px;
  background: var(--surface);
}

.overview-item {
  gap: 5px;
  padding: 10px 12px;
  border-radius: 16px;
  background: var(--surface-soft);
}

.overview-item strong {
  font-size: 1.16rem;
}

.control-panel {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr)) auto;
  gap: 14px;
  align-items: end;
  margin-top: 24px;
  padding: 14px;
  border-radius: 22px;
  background: var(--surface);
}

.home-panel {
  display: grid;
  gap: 18px;
  padding: 20px;
  border-radius: 24px;
  background: var(--surface);
}

.home-copy {
  display: grid;
  gap: 12px;
}

.home-support {
  margin: 0;
  color: var(--text-muted);
  font-size: 0.94rem;
  line-height: 1.7;
}

.home-actions {
  display: flex;
  gap: 10px;
  flex-wrap: wrap;
}

.control-group {
  gap: 10px;
}

.segmented {
  display: flex;
  gap: 8px;
  flex-wrap: wrap;
}

#size-switcher {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 8px;
}

.segment-button {
  appearance: none;
  border: 1px solid rgba(18, 25, 36, 0.08);
  border-radius: 999px;
  min-height: 48px;
  padding: 11px 14px;
  background: rgba(255, 255, 255, 0.88);
  color: var(--text-main);
  font: inherit;
  font-weight: 700;
  cursor: pointer;
  touch-action: manipulation;
  transition: transform 140ms ease, border-color 140ms ease, background-color 140ms ease, box-shadow 140ms ease;
}

.segment-button.is-active {
  color: white;
  background: linear-gradient(180deg, var(--accent), var(--accent-strong));
  border-color: transparent;
  box-shadow: var(--shadow-button);
}

.segment-button:hover {
  transform: translateY(-1px);
}

.top-actions {
  display: flex;
  gap: 10px;
  flex-wrap: wrap;
  justify-content: end;
}

.view-panel {
  margin-top: 26px;
}

.section-head,
.difficulty-head,
.selection-meta,
.selection-card-head,
.notice-actions,
.dashboard {
  display: flex;
}

.section-head,
.difficulty-head,
.selection-card-head {
  justify-content: space-between;
  align-items: start;
  gap: 16px;
}

.selection-meta {
  gap: 10px;
  flex-wrap: wrap;
}

.selection-badge,
.selection-card-badge {
  display: inline-flex;
  align-items: center;
  min-height: 30px;
  padding: 5px 12px;
  border-radius: 999px;
  font-size: 0.84rem;
  font-weight: 700;
}

.selection-badge {
  color: var(--accent-strong);
  background: var(--accent-soft);
}

.selection-note {
  margin: 14px 0 0;
}

#selection-content {
  margin-top: 22px;
}

.difficulty-stack {
  display: grid;
  gap: 18px;
}

.difficulty-block {
  padding: 18px;
  border-radius: 24px;
  background: rgba(255, 255, 255, 0.54);
}

.difficulty-title {
  font-size: 1.16rem;
}

.difficulty-text {
  margin: 8px 0 0;
}

.selection-grid {
  display: grid;
  grid-template-columns: repeat(3, minmax(0, 1fr));
  gap: 12px;
  margin-top: 16px;
}

.records-layout,
.records-metrics,
.achievement-grid {
  display: grid;
}

.records-layout {
  gap: 16px;
  margin-top: 22px;
}

.records-section {
  padding: 18px;
  border-radius: 24px;
  background: rgba(255, 255, 255, 0.56);
}

.records-copy {
  margin: 8px 0 0;
  line-height: 1.65;
}

.records-metrics {
  grid-template-columns: repeat(4, minmax(0, 1fr));
  gap: 12px;
  margin-top: 16px;
}

.metric-card {
  display: grid;
  gap: 6px;
  padding: 14px;
  border-radius: 18px;
  background: var(--surface-strong);
}

.metric-value {
  font-size: 1.48rem;
  font-weight: 800;
}

.metric-label {
  font-size: 0.94rem;
}

.metric-note {
  font-size: 0.84rem;
}

.achievement-grid {
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 12px;
  margin-top: 16px;
}

.achievement-card {
  display: grid;
  gap: 6px;
  padding: 14px;
  border-radius: 18px;
  background: var(--surface-strong);
}

.achievement-card.is-unlocked {
  background: linear-gradient(180deg, rgba(255, 255, 255, 0.98), rgba(233, 247, 237, 0.92));
}

.achievement-title {
  font-weight: 700;
}

.achievement-meta {
  margin: 0;
  font-size: 0.9rem;
}

.records-actions {
  margin-top: 18px;
}

.selection-card {
  width: 100%;
  padding: 14px;
  border-radius: 20px;
  background: var(--surface-strong);
  text-align: left;
  cursor: pointer;
  touch-action: manipulation;
  transition: transform 160ms ease, border-color 180ms ease, box-shadow 180ms ease, background-color 180ms ease;
}

.selection-card.is-cleared {
  background: linear-gradient(180deg, rgba(255, 255, 255, 0.96), rgba(233, 247, 237, 0.92));
}

.selection-card.is-active {
  border-color: rgba(37, 109, 224, 0.22);
  box-shadow: 0 0 0 4px rgba(37, 109, 224, 0.08);
}

.selection-card.is-locked {
  cursor: not-allowed;
  opacity: 0.65;
}

.selection-card.is-special {
  background: linear-gradient(180deg, rgba(255, 255, 255, 0.98), rgba(255, 248, 225, 0.95));
}

.selection-card-body {
  gap: 8px;
  margin-top: 12px;
}

.selection-card-title {
  font-weight: 700;
}

.selection-card-meta {
  margin: 0;
  font-size: 0.92rem;
}

.selection-card-badge.is-clear {
  color: var(--success-text);
  background: var(--success-bg);
}

.selection-card-badge.is-open {
  color: var(--accent-strong);
  background: var(--accent-soft);
}

.selection-card-badge.is-locked {
  color: var(--text-muted);
  background: rgba(17, 24, 39, 0.08);
}

.selection-card-badge.is-daily {
  color: var(--daily-text);
  background: var(--daily-soft);
}

.dashboard {
  gap: 14px;
  flex-wrap: wrap;
}

.status-tile {
  gap: 6px;
  padding: 16px 18px;
  border-radius: 20px;
  background: var(--surface);
  flex: 1 1 0;
  min-width: 180px;
}

.status-tile strong {
  font-size: 1.32rem;
}

.status-tile-wide {
  min-width: 240px;
  flex: 1.4 1 0;
}

.status-tile-wide strong {
  font-size: 1.54rem;
}

.board-wrap {
  margin-top: 24px;
}

.board {
  --grid-size: 5;
  --board-max: 430px;
  --cell-gap: 10px;
  --board-pad: 14px;
  display: grid;
  grid-template-columns: repeat(var(--grid-size), 1fr);
  gap: var(--cell-gap);
  width: min(100%, var(--board-max));
  margin-inline: auto;
  padding: var(--board-pad);
  aspect-ratio: 1 / 1;
  border-radius: 26px;
  background: linear-gradient(180deg, var(--board-frame-top), var(--board-frame-bottom));
  box-shadow:
    inset 0 1px 0 rgba(255, 255, 255, 0.08),
    0 18px 36px rgba(18, 25, 36, 0.3);
  transition: box-shadow 220ms ease, transform 220ms ease, width 180ms ease;
  touch-action: manipulation;
}

.board.size-3 {
  --grid-size: 3;
  --board-max: 380px;
  --cell-gap: 12px;
  --board-pad: 16px;
}

.board.size-5 {
  --grid-size: 5;
  --board-max: 430px;
  --cell-gap: 10px;
  --board-pad: 14px;
}

.board.size-6 {
  --grid-size: 6;
  --board-max: 450px;
  --cell-gap: 8px;
  --board-pad: 12px;
}

.board.size-7 {
  --grid-size: 7;
  --board-max: 470px;
  --cell-gap: 6px;
  --board-pad: 11px;
}

.board.is-reacting {
  transform: scale(1.01);
}

.board.is-cleared {
  transform: translateY(-2px);
  box-shadow:
    0 0 0 5px rgba(88, 181, 122, 0.14),
    0 22px 40px rgba(29, 63, 42, 0.18),
    inset 0 1px 0 rgba(255, 255, 255, 0.08);
}

.board.is-special {
  box-shadow:
    0 0 0 5px rgba(255, 199, 86, 0.14),
    0 22px 44px rgba(141, 100, 13, 0.12),
    inset 0 1px 0 rgba(255, 255, 255, 0.08);
}

.cell {
  appearance: none;
  border: none;
  width: 100%;
  aspect-ratio: 1 / 1;
  min-width: 0;
  border-radius: 18px;
  background: var(--cell-dark);
  border: 1px solid var(--cell-line);
  cursor: pointer;
  touch-action: manipulation;
  transition:
    transform 140ms ease,
    background-color 200ms ease,
    box-shadow 200ms ease,
    border-color 200ms ease,
    opacity 180ms ease,
    filter 180ms ease;
  box-shadow:
    inset 0 1px 0 rgba(255, 255, 255, 0.04),
    inset 0 -8px 14px rgba(0, 0, 0, 0.2);
}

.board.size-3 .cell {
  border-radius: 22px;
}

.board.size-6 .cell,
.board.size-7 .cell {
  border-radius: 14px;
}

.cell:active {
  transform: scale(0.96);
}

.cell:disabled {
  cursor: default;
}

.cell:focus-visible,
.button:focus-visible,
.segment-button:focus-visible,
.selection-card:focus-visible {
  outline: 3px solid rgba(37, 109, 224, 0.24);
  outline-offset: 3px;
}

.cell.is-light {
  background: var(--cell-light);
  border-color: rgba(163, 184, 205, 0.72);
  box-shadow:
    inset 0 1px 0 rgba(255, 255, 255, 0.9),
    0 0 0 1px rgba(255, 255, 255, 0.65);
}

.cell.is-flipped {
  animation: pulse 220ms ease;
  filter: brightness(1.04);
}

.cell.is-clearing {
  animation: settle 340ms ease;
}

.notice-panel {
  margin-top: 24px;
  padding: 18px 18px 20px;
  border-radius: 22px;
  background: var(--surface);
  transition: background-color 220ms ease, border-color 220ms ease, transform 220ms ease, box-shadow 220ms ease;
}

.notice-panel.is-cleared {
  background: var(--success-bg);
  border-color: rgba(25, 95, 52, 0.14);
  transform: translateY(-1px);
  box-shadow: 0 12px 30px rgba(29, 63, 42, 0.08);
}

.notice-panel.is-special {
  background: var(--daily-soft);
  border-color: rgba(141, 100, 13, 0.14);
}

.notice-title {
  margin-top: 10px;
  font-size: clamp(1.3rem, 3vw, 1.8rem);
}

.notice-text {
  margin: 10px 0 0;
}

.result-copy-preview {
  margin: 0;
  line-height: 1.65;
}

.notice-panel.is-cleared .notice-kicker,
.notice-panel.is-cleared .notice-title {
  color: var(--success-text);
}

.notice-panel.is-special .notice-kicker,
.notice-panel.is-special .notice-title {
  color: var(--daily-text);
}

.notice-actions {
  gap: 10px;
  flex-wrap: wrap;
  margin-top: 18px;
}

.notice-actions .button[hidden] {
  display: none;
}

.button {
  appearance: none;
  border: none;
  border-radius: 999px;
  min-height: 48px;
  padding: 13px 18px;
  font: inherit;
  font-weight: 700;
  cursor: pointer;
  touch-action: manipulation;
  transition: transform 140ms ease, box-shadow 140ms ease, filter 140ms ease, background-color 140ms ease, border-color 140ms ease;
}

.button:active {
  transform: translateY(1px);
}

.app-footer {
  display: flex;
  justify-content: space-between;
  gap: 16px;
  align-items: center;
  margin-top: 26px;
  padding-top: 18px;
  border-top: 1px solid rgba(18, 25, 36, 0.08);
  color: var(--text-muted);
  font-size: 0.84rem;
}

.footer-copy,
.footer-links {
  display: flex;
  gap: 12px;
  flex-wrap: wrap;
  align-items: center;
}

.footer-links a {
  color: var(--accent-strong);
  text-decoration: none;
}

.footer-links a[aria-disabled="true"] {
  opacity: 0.7;
  pointer-events: none;
}

.button-primary {
  color: white;
  background: linear-gradient(180deg, var(--accent), var(--accent-strong));
  box-shadow: var(--shadow-button);
}

.button-secondary {
  color: var(--text-main);
  background: rgba(255, 255, 255, 0.94);
  border: 1px solid rgba(17, 24, 39, 0.08);
}

.button-ghost {
  color: var(--accent-strong);
  background: rgba(37, 109, 224, 0.08);
}

@keyframes pulse {
  0% {
    transform: scale(1);
  }

  45% {
    transform: scale(0.9);
  }

  100% {
    transform: scale(1);
  }
}

@keyframes settle {
  0% {
    transform: scale(1);
    filter: brightness(1);
  }

  35% {
    transform: scale(0.94);
    filter: brightness(1.08);
  }

  100% {
    transform: scale(1);
    filter: brightness(1);
  }
}

@media (max-width: 900px) {
  .selection-grid {
    grid-template-columns: repeat(2, minmax(0, 1fr));
  }

  .records-metrics {
    grid-template-columns: repeat(2, minmax(0, 1fr));
  }

  .control-panel {
    grid-template-columns: 1fr;
  }

  .top-actions {
    justify-content: start;
  }
}

@media (max-width: 640px) {
  .app-shell {
    place-items: start stretch;
    padding:
      max(12px, env(safe-area-inset-top))
      max(12px, env(safe-area-inset-right))
      max(18px, env(safe-area-inset-bottom))
      max(12px, env(safe-area-inset-left));
  }

  .game-card {
    width: 100%;
    border-radius: 22px;
    padding: 16px 12px 18px;
  }

  .hero {
    gap: 14px;
  }

  .overview-panel {
    grid-template-columns: 1fr;
  }

  .hero-topline {
    display: grid;
    gap: 10px;
  }

  .lang-switcher {
    min-width: 0;
  }

  .section-head,
  .difficulty-head,
  .notice-actions {
    display: grid;
  }

  .section-head,
  .difficulty-head {
    gap: 12px;
  }

  .selection-grid {
    grid-template-columns: 1fr;
  }

  .records-metrics,
  .achievement-grid {
    grid-template-columns: 1fr;
  }

  .dashboard {
    display: grid;
    grid-template-columns: repeat(2, minmax(0, 1fr));
    gap: 10px;
  }

  .status-tile,
  .status-tile-wide {
    min-width: 0;
    padding: 14px;
  }

  .status-tile-wide {
    grid-column: 1 / -1;
  }

  .status-tile strong {
    font-size: 1.18rem;
  }

  .status-tile-wide strong {
    font-size: 1.32rem;
  }

  .board.size-3 {
    --board-max: min(86vw, 330px);
    --cell-gap: 10px;
  }

  .board.size-5 {
    --board-max: min(92vw, 380px);
    --cell-gap: 7px;
    --board-pad: 10px;
  }

  .board.size-6 {
    --board-max: min(92vw, 390px);
    --cell-gap: 6px;
    --board-pad: 9px;
  }

  .board.size-7 {
    --board-max: min(92vw, 396px);
    --cell-gap: 5px;
    --board-pad: 8px;
  }

  .cell {
    border-radius: 14px;
  }

  .board.size-3 .cell {
    border-radius: 18px;
  }

  .board.size-6 .cell,
  .board.size-7 .cell {
    border-radius: 10px;
  }

  .button,
  .segment-button {
    width: 100%;
  }

  .segmented,
  .top-actions,
  .home-actions {
    display: grid;
  }

  .app-footer {
    display: grid;
    justify-content: stretch;
    gap: 10px;
  }
}

@media (hover: hover) and (pointer: fine) {
  .segment-button:hover {
    transform: translateY(-1px);
  }

  .selection-card:hover {
    transform: translateY(-2px);
    border-color: rgba(37, 109, 224, 0.18);
    box-shadow: 0 14px 28px rgba(26, 38, 55, 0.08);
  }

  .cell:hover {
    transform: translateY(-1px);
  }

  .button:hover {
    transform: translateY(-1px);
  }
}