:root {
  color-scheme: light;
  --bg: #f8fafc;
  --surface: #ffffff;
  --panel: #ffffff;
  --text: #0f172a;
  --muted: #64748b;
  --primary: #2563eb;
  --primary-dark: #1d4ed8;
  --accent: #a855f7;
  --border: #e2e8f0;
  --link: #1d4ed8;
  --button-bg: #2563eb;
  --button-text: #ffffff;
  --button-secondary-bg: transparent;
  --button-secondary-text: #0f172a;
  --shadow: 0 10px 30px rgba(15, 23, 42, 0.08);
  --radius-lg: 18px;
  --radius-md: 14px;
  --radius-sm: 10px;
  --space-1: 6px;
  --space-2: 10px;
  --space-3: 14px;
  --space-4: 18px;
  --space-5: 24px;
  --space-6: 32px;
  --space-7: 40px;
  --max-width: 1080px;
}

[data-theme="dark"] {
  color-scheme: dark;
  --bg: #0b1120;
  --surface: #0f172a;
  --panel: #0f172a;
  --text: #f8fafc;
  --muted: #94a3b8;
  --border: #1e293b;
  --link: #93c5fd;
  --button-bg: #3b82f6;
  --button-text: #0b1120;
  --button-secondary-bg: rgba(148, 163, 184, 0.08);
  --button-secondary-text: #e2e8f0;
  --shadow: 0 12px 30px rgba(2, 6, 23, 0.6);
}

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

@media (prefers-color-scheme: dark) {
  :root:not([data-theme]) {
    color-scheme: dark;
    --bg: #0b1120;
    --surface: #0f172a;
    --panel: #0f172a;
    --text: #f8fafc;
    --muted: #94a3b8;
    --border: #1e293b;
    --link: #93c5fd;
    --button-bg: #3b82f6;
    --button-text: #0b1120;
    --button-secondary-bg: rgba(148, 163, 184, 0.08);
    --button-secondary-text: #e2e8f0;
    --shadow: 0 12px 30px rgba(2, 6, 23, 0.6);
  }
}

* {
  box-sizing: border-box;
}

body {
  margin: 0;
  font-family: "Nunito", system-ui, -apple-system, sans-serif;
  background: var(--bg);
  color: var(--text);
}

main {
  padding: 72px 0 56px;
}

.container {
  width: min(var(--max-width), 92vw);
  margin: 0 auto;
}

.hero {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(260px, 1fr));
  gap: var(--space-6);
  align-items: center;
}

.hero-card {
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--radius-lg);
  padding: var(--space-6);
  box-shadow: var(--shadow);
}

.hero-card h2 {
  margin: 0 0 var(--space-2);
  font-family: "Poppins", sans-serif;
  font-size: 1.3rem;
}

.hero h1 {
  font-family: "Poppins", sans-serif;
  font-size: clamp(2rem, 2.8vw, 3rem);
  margin: 0 0 var(--space-2);
}

.eyebrow {
  text-transform: uppercase;
  letter-spacing: 0.2em;
  font-size: 0.75rem;
  color: var(--muted);
  margin: 0 0 var(--space-2);
  font-family: "Poppins", sans-serif;
}

.hero p {
  margin: 0 0 var(--space-4);
  color: var(--muted);
  line-height: 1.6;
}

.hero-actions {
  display: flex;
  flex-wrap: wrap;
  gap: var(--space-2);
}

.button,
button.button {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  padding: 12px 18px;
  border-radius: var(--radius-sm);
  border: 1px solid transparent;
  text-decoration: none;
  font-family: "Poppins", sans-serif;
  font-weight: 700;
  cursor: pointer;
  background: var(--button-bg);
  color: var(--button-text);
  transition: transform 0.15s ease, box-shadow 0.15s ease, background 0.15s ease;
}

.button.secondary {
  background: var(--button-secondary-bg);
  border-color: var(--border);
  color: var(--button-secondary-text);
}

.button.ghost {
  background: rgba(37, 99, 235, 0.12);
  color: var(--primary);
  border-color: transparent;
}

.button:hover,
button.button:hover {
  transform: translateY(-1px);
  box-shadow: 0 6px 16px rgba(37, 99, 235, 0.2);
}

.button:focus-visible,
button.button:focus-visible,
select:focus-visible,
summary:focus-visible,
.theme-option:focus-visible {
  outline: 3px solid rgba(37, 99, 235, 0.6);
  outline-offset: 2px;
}

.section {
  margin-top: var(--space-7);
}

.section h2 {
  font-family: "Poppins", sans-serif;
  font-size: 1.4rem;
  margin: 0 0 var(--space-3);
}

.card-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(180px, 1fr));
  gap: var(--space-3);
}

.card {
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--radius-md);
  padding: var(--space-4);
  box-shadow: var(--shadow);
  display: grid;
  gap: var(--space-2);
}

.card h3 {
  margin: 0;
  font-family: "Poppins", sans-serif;
  font-size: 1.05rem;
}

.card p {
  margin: 0;
  color: var(--muted);
  font-size: 0.95rem;
}

.ad-slot {
  margin: var(--space-6) 0;
  padding: var(--space-4);
  border: 1px dashed var(--border);
  border-radius: var(--radius-md);
  text-align: center;
  font-family: "Poppins", sans-serif;
  font-size: 0.75rem;
  letter-spacing: 0.08em;
  text-transform: uppercase;
  color: var(--muted);
  background: rgba(148, 163, 184, 0.08);
}

.faq details {
  border-top: 1px solid var(--border);
  padding: var(--space-3) 0;
}

.faq details:first-of-type {
  border-top: none;
}

.faq summary {
  cursor: pointer;
  font-family: "Poppins", sans-serif;
  font-size: 0.95rem;
}

.faq p {
  margin: var(--space-2) 0 0;
  color: var(--muted);
}

.footer {
  padding: var(--space-5) 0 var(--space-6);
  text-align: center;
  color: var(--muted);
  font-size: 0.95rem;
}

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

/* Game page */
.game-hero {
  display: flex;
  flex-wrap: wrap;
  gap: var(--space-4);
  align-items: flex-start;
  justify-content: space-between;
  margin-bottom: var(--space-6);
}

.game-hero > div:first-child {
  flex: 1 1 320px;
}

.theme-toggle {
  display: grid;
  gap: var(--space-2);
  align-items: start;
  justify-items: start;
  padding: var(--space-3);
  border-radius: var(--radius-md);
  border: 1px solid var(--border);
  background: var(--surface);
  box-shadow: var(--shadow);
}

.theme-label {
  font-family: "Poppins", sans-serif;
  font-size: 0.9rem;
  color: var(--muted);
  text-transform: uppercase;
  letter-spacing: 0.18em;
}

.theme-options {
  display: inline-flex;
  gap: var(--space-1);
  background: rgba(148, 163, 184, 0.12);
  padding: 4px;
  border-radius: 999px;
}

.theme-option {
  border: 1px solid transparent;
  background: transparent;
  color: var(--text);
  font-family: "Poppins", sans-serif;
  font-size: 0.85rem;
  padding: 8px 14px;
  border-radius: 999px;
  cursor: pointer;
}

.theme-option[aria-pressed="true"] {
  background: var(--button-bg);
  color: var(--button-text);
  box-shadow: 0 6px 12px rgba(15, 23, 42, 0.2);
}

.how-to-card {
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--radius-lg);
  padding: var(--space-6);
  box-shadow: var(--shadow);
  display: grid;
  gap: var(--space-4);
  margin-bottom: var(--space-6);
}

.how-to-card h2 {
  font-family: "Poppins", sans-serif;
  font-size: clamp(1.6rem, 3vw, 2.2rem);
  margin: 0 0 var(--space-2);
}

.how-to-header p {
  margin: 0;
  color: var(--muted);
  line-height: 1.6;
}

.how-to-steps {
  margin: 0;
  padding-left: 1.2rem;
  display: grid;
  gap: var(--space-2);
}

.how-to-steps li {
  color: var(--text);
}

.how-to-benefits {
  display: grid;
  gap: var(--space-2);
  color: var(--muted);
  line-height: 1.7;
}

.benefit-list {
  margin: 0;
  padding-left: 1.2rem;
  display: grid;
  gap: var(--space-1);
  color: var(--text);
}

.game-shell {
  display: grid;
  gap: var(--space-5);
}

.control-panel {
  display: grid;
  gap: var(--space-3);
  background: var(--surface);
  border-radius: var(--radius-lg);
  border: 1px solid var(--border);
  padding: var(--space-4);
  box-shadow: var(--shadow);
}

.controls {
  display: flex;
  flex-wrap: wrap;
  gap: var(--space-2);
  align-items: center;
}

.controls label {
  font-family: "Poppins", sans-serif;
  font-weight: 600;
}

.controls select {
  padding: 10px 12px;
  border-radius: var(--radius-sm);
  border: 1px solid var(--border);
  background: var(--surface);
  color: var(--text);
}

.stats {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(140px, 1fr));
  gap: var(--space-3);
}

.stat {
  background: rgba(37, 99, 235, 0.12);
  border-radius: var(--radius-md);
  padding: var(--space-3);
  border: 1px solid rgba(37, 99, 235, 0.18);
}

.stat span {
  font-size: 0.8rem;
  color: var(--muted);
  display: block;
}

.stat strong {
  font-family: "Poppins", sans-serif;
  font-size: 1.1rem;
}

.board-wrap {
  display: grid;
  place-items: center;
}

.board {
  width: min(92vw, 480px);
  aspect-ratio: 1;
  border-radius: var(--radius-lg);
  background: linear-gradient(160deg, rgba(37, 99, 235, 0.12), rgba(168, 85, 247, 0.12));
  position: relative;
  border: 1px solid var(--border);
  box-shadow: var(--shadow);
}

.tile {
  position: absolute;
  display: grid;
  place-items: center;
  border-radius: 16px;
  background: var(--surface);
  border: 2px solid rgba(37, 99, 235, 0.2);
  color: var(--text);
  font-family: "Poppins", sans-serif;
  font-size: clamp(1rem, 3vw, 1.6rem);
  font-weight: 700;
  box-shadow: 0 8px 18px rgba(15, 23, 42, 0.15);
  transition: transform 0.2s ease;
  cursor: pointer;
}

.tile:focus-visible {
  outline: 3px solid rgba(168, 85, 247, 0.5);
  outline-offset: 2px;
}

.best-time {
  margin-top: var(--space-2);
  font-size: 0.95rem;
  color: var(--muted);
}

.win-modal {
  position: fixed;
  inset: 0;
  background: rgba(15, 23, 42, 0.6);
  display: none;
  align-items: center;
  justify-content: center;
  z-index: 9999;
  padding: var(--space-4);
}

.win-modal.active {
  display: flex;
}

.win-card {
  background: var(--surface);
  border-radius: var(--radius-lg);
  padding: var(--space-6);
  border: 1px solid var(--border);
  max-width: 420px;
  width: 100%;
  text-align: center;
  box-shadow: var(--shadow);
}

.win-card h2 {
  margin: 0 0 var(--space-2);
  font-family: "Poppins", sans-serif;
  font-size: 1.6rem;
}

.win-stats {
  margin: var(--space-3) 0;
  display: grid;
  gap: var(--space-2);
  color: var(--muted);
}

.confetti {
  pointer-events: none;
  position: fixed;
  inset: 0;
  overflow: hidden;
  z-index: 9998;
}

.confetti span {
  position: absolute;
  width: 10px;
  height: 16px;
  background: var(--primary);
  animation: confetti-fall 1.8s ease-in-out forwards;
  border-radius: 4px;
}

@keyframes confetti-fall {
  0% {
    transform: translateY(-20px) rotate(0deg);
    opacity: 1;
  }
  100% {
    transform: translateY(120vh) rotate(360deg);
    opacity: 0;
  }
}

@media (prefers-reduced-motion: reduce) {
  .tile {
    transition: none;
  }
  .confetti span {
    animation: none;
  }
}