:root {
  color-scheme: light dark;
  --font-body: "Trebuchet MS", "Segoe UI", sans-serif;
  --font-display: Georgia, "Times New Roman", serif;
  --shadow-soft: 0 18px 45px rgba(15, 23, 42, 0.12);
  --shadow-card: 0 10px 24px rgba(15, 23, 42, 0.16);
  --radius-large: 1.5rem;
  --radius-medium: 1rem;
  --radius-small: 0.75rem;
  --duration-fast: 180ms;
  --duration-medium: 320ms;
  --bg: #f5f1e8;
  --bg-accent: rgba(181, 147, 87, 0.12);
  --surface: rgba(255, 251, 245, 0.88);
  --surface-strong: #fffdfa;
  --surface-muted: #ede5d6;
  --text: #1f1c19;
  --text-soft: #5e544a;
  --border: rgba(96, 72, 40, 0.2);
  --primary: #8c4f1f;
  --primary-strong: #673815;
  --secondary: #245c52;
  --secondary-soft: rgba(36, 92, 82, 0.14);
  --focus: #1e6ad6;
  --success: #256d46;
  --danger: #a23b30;
}

@media (prefers-color-scheme: dark) {
  :root {
    --bg: #14181c;
    --bg-accent: rgba(109, 153, 141, 0.14);
    --surface: rgba(23, 30, 35, 0.88);
    --surface-strong: #1c252b;
    --surface-muted: #243039;
    --text: #f2f0eb;
    --text-soft: #b7beb7;
    --border: rgba(219, 233, 230, 0.14);
    --primary: #f2a65a;
    --primary-strong: #f9c28b;
    --secondary: #8fd3c1;
    --secondary-soft: rgba(143, 211, 193, 0.16);
    --focus: #82b8ff;
    --success: #75cf9f;
    --danger: #f08c7f;
  }
}

:root[data-theme="light"] {
  color-scheme: light;
}

:root[data-theme="dark"] {
  color-scheme: dark;
  --bg: #14181c;
  --bg-accent: rgba(109, 153, 141, 0.14);
  --surface: rgba(23, 30, 35, 0.88);
  --surface-strong: #1c252b;
  --surface-muted: #243039;
  --text: #f2f0eb;
  --text-soft: #b7beb7;
  --border: rgba(219, 233, 230, 0.14);
  --primary: #f2a65a;
  --primary-strong: #f9c28b;
  --secondary: #8fd3c1;
  --secondary-soft: rgba(143, 211, 193, 0.16);
  --focus: #82b8ff;
  --success: #75cf9f;
  --danger: #f08c7f;
}

* {
  box-sizing: border-box;
}

html {
  font-size: 16px;
}

body {
  margin: 0;
  min-height: 100vh;
  font-family: var(--font-body);
  color: var(--text);
  background:
    radial-gradient(circle at top left, var(--bg-accent), transparent 30%),
    linear-gradient(180deg, var(--bg), color-mix(in srgb, var(--bg) 84%, #000 16%));
}

button,
select,
input {
  font: inherit;
}

button,
select {
  border-radius: var(--radius-small);
}

:focus-visible {
  outline: 3px solid var(--focus);
  outline-offset: 3px;
}

.skip-link,
.sr-only {
  position: absolute;
}

.skip-link {
  left: 1rem;
  top: 1rem;
  transform: translateY(-200%);
  padding: 0.75rem 1rem;
  background: var(--surface-strong);
  color: var(--text);
  z-index: 20;
}

.skip-link:focus {
  transform: translateY(0);
}

.sr-only {
  width: 1px;
  height: 1px;
  overflow: hidden;
  clip: rect(0 0 0 0);
  clip-path: inset(50%);
  white-space: nowrap;
}

.app-shell {
  width: min(1100px, calc(100% - 2rem));
  margin: 0 auto;
  padding: 1.25rem 0 2rem;
}

.hero,
.panel,
.metric-card,
.score-card {
  backdrop-filter: blur(14px);
}

.hero,
.panel {
  background: var(--surface);
  border: 1px solid var(--border);
  box-shadow: var(--shadow-soft);
}

.hero {
  display: flex;
  align-items: start;
  justify-content: space-between;
  gap: 1rem;
  padding: 1.5rem;
  border-radius: var(--radius-large);
}

.eyebrow {
  margin: 0 0 0.4rem;
  color: var(--secondary);
  font-size: 0.95rem;
  text-transform: uppercase;
  letter-spacing: 0.08em;
}

h1,
h2,
h3 {
  margin: 0;
  font-family: var(--font-display);
}

h1 {
  font-size: clamp(2rem, 5vw, 3.4rem);
  line-height: 0.95;
}

.intro,
.status-copy,
.board-help {
  color: var(--text-soft);
}

.intro {
  max-width: 60ch;
  margin: 0.85rem 0 0;
}

.panel {
  margin-top: 1rem;
  padding: 1.25rem;
  border-radius: var(--radius-large);
}

.panel-header,
.action-row,
.settings-actions {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 0.75rem;
  flex-wrap: wrap;
}

.settings-grid,
.status-grid,
.scoreboard {
  display: grid;
  gap: 1rem;
}

.settings-grid {
  grid-template-columns: repeat(auto-fit, minmax(180px, 1fr));
  margin-top: 1rem;
}

fieldset,
.stacked-label {
  padding: 1rem;
  border: 1px solid var(--border);
  border-radius: var(--radius-medium);
  background: var(--surface-strong);
}

fieldset {
  min-inline-size: 0;
}

legend {
  padding: 0 0.35rem;
  font-weight: 700;
}

fieldset label,
.stacked-label {
  display: grid;
  gap: 0.65rem;
}

select {
  width: 100%;
  min-height: 2.75rem;
  padding: 0.65rem 0.85rem;
  border: 1px solid var(--border);
  background: var(--surface-strong);
  color: var(--text);
}

.primary-button,
.ghost-button,
.memory-card {
  cursor: pointer;
}

.primary-button,
.ghost-button {
  min-height: 2.75rem;
  padding: 0.7rem 1rem;
  border: 1px solid transparent;
  transition: transform var(--duration-fast) ease, background var(--duration-fast) ease;
}

.primary-button {
  background: var(--primary);
  color: #fff;
}

.primary-button:hover,
.primary-button:focus-visible {
  background: var(--primary-strong);
}

.ghost-button {
  background: transparent;
  color: var(--text);
  border-color: var(--border);
}

.ghost-button:hover,
.ghost-button:focus-visible {
  background: var(--surface-muted);
}

.status-grid {
  grid-template-columns: repeat(auto-fit, minmax(140px, 1fr));
  margin-top: 1rem;
}

.metric-card,
.score-card {
  padding: 1rem;
  border-radius: var(--radius-medium);
  background: var(--surface-strong);
  border: 1px solid var(--border);
}

.metric-label {
  display: block;
  margin-bottom: 0.4rem;
  color: var(--text-soft);
}

.active-player-card {
  background:
    linear-gradient(135deg, var(--secondary-soft), transparent),
    var(--surface-strong);
}

.scoreboard {
  grid-template-columns: repeat(auto-fit, minmax(170px, 1fr));
  margin-top: 1rem;
}

.score-card.is-active {
  border-color: var(--secondary);
  box-shadow: inset 0 0 0 1px var(--secondary);
}

.turn-indicator {
  margin-bottom: 0;
  color: var(--text-soft);
}

.status-copy {
  margin: 1rem 0 0;
  min-height: 1.5rem;
}

.board-panel {
  overflow: hidden;
}

.game-board {
  --rows: 4;
  --columns: 4;
  display: grid;
  grid-template-columns: repeat(var(--columns), minmax(0, 1fr));
  gap: 0.75rem;
  margin-top: 1rem;
  width: min(100%, calc((100svh - 13rem) * (var(--columns) / var(--rows))));
  max-width: 100%;
  margin-inline: auto;
}

.memory-card {
  position: relative;
  width: 100%;
  aspect-ratio: 1 / 1;
  border: 1px solid var(--border);
  border-radius: var(--radius-medium);
  background: transparent;
  color: var(--text);
  box-shadow: var(--shadow-card);
  transform-style: preserve-3d;
  transition: transform var(--duration-medium) ease;
  -webkit-tap-highlight-color: transparent;
}

.memory-card[disabled] {
  cursor: default;
}

.memory-card.is-flipped,
.memory-card.is-matched {
  transform: rotateY(180deg);
}

.card-face {
  position: absolute;
  inset: 0;
  display: grid;
  place-items: center;
  padding: 0.5rem;
  border-radius: inherit;
  backface-visibility: hidden;
}

.card-front {
  background:
    linear-gradient(135deg, var(--secondary-soft), transparent 60%),
    var(--surface-strong);
  font-size: clamp(1.75rem, 6vw, 2.4rem);
  transform: rotateY(180deg);
}

.card-back {
  background:
    radial-gradient(circle at top, rgba(255, 255, 255, 0.16), transparent 55%),
    linear-gradient(145deg, var(--primary), var(--primary-strong));
  color: #fff;
  font-size: clamp(1.4rem, 5vw, 1.9rem);
}

.memory-card.is-matched .card-front {
  box-shadow: inset 0 0 0 2px var(--success);
}

@media (min-width: 900px) and (min-height: 700px) {
  .app-shell {
    display: grid;
    grid-template-columns: minmax(18rem, 22rem) minmax(0, 1fr);
    gap: 1rem;
    align-items: start;
  }

  .hero,
  .settings-panel,
  .status-panel,
  .board-panel {
    margin-top: 0;
  }

  .hero,
  .settings-panel,
  .status-panel {
    grid-column: 1;
  }

  .board-panel {
    grid-column: 2;
    grid-row: 1 / span 3;
    position: sticky;
    top: 1rem;
    max-height: calc(100svh - 2rem);
    display: flex;
    flex-direction: column;
  }

  .board-help {
    margin: 0;
  }

  .game-board {
    width: min(100%, calc((100svh - 10rem) * (var(--columns) / var(--rows))));
    gap: 0.6rem;
  }
}

@media (max-width: 640px) {
  .app-shell {
    width: min(100% - 1rem, 1100px);
    padding-top: 0.5rem;
  }

  .hero,
  .panel {
    padding: 1rem;
    border-radius: 1.2rem;
  }

  .game-board {
    gap: 0.55rem;
    width: 100%;
  }
}

@media (prefers-reduced-motion: reduce) {
  *,
  *::before,
  *::after {
    scroll-behavior: auto !important;
    transition-duration: 0.01ms !important;
    animation-duration: 0.01ms !important;
    animation-iteration-count: 1 !important;
  }
}

footer {
  text-align: center;
  padding: 1rem;
  margin-top: 2rem;
}

.footer-link {
  font-size: 0.875rem;
  color: var(--text-soft);
  text-decoration: none;
  transition: color var(--duration-fast);
}

.footer-link:hover {
  color: var(--text);
}

.footer-link:focus-visible {
  outline: 3px solid var(--focus);
  outline-offset: 3px;
}