:root {
  color-scheme: dark;
  --bg: #101820;
  --surface: #16222d;
  --surface-2: #1f3040;
  --text: #f7fbff;
  --muted: #aac0cf;
  --line: rgba(255, 255, 255, 0.12);
  --primary: #2fbf71;
  --primary-strong: #19a45a;
  --secondary: #ffb703;
  --ink: #101820;
  --danger: #ef476f;
  --radius: 8px;
  --shadow: 0 24px 80px rgba(0, 0, 0, 0.28);
  font-family: Inter, system-ui, -apple-system, BlinkMacSystemFont, "Segoe UI", sans-serif;
}

:root[data-theme="light"] {
  color-scheme: light;
  --bg: #f6f8f5;
  --surface: #ffffff;
  --surface-2: #edf2ec;
  --text: #17212b;
  --muted: #526371;
  --line: rgba(16, 24, 32, 0.12);
  --shadow: 0 20px 60px rgba(26, 42, 54, 0.12);
}

* {
  box-sizing: border-box;
}

html {
  scroll-behavior: smooth;
}

body {
  margin: 0;
  background:
    linear-gradient(140deg, rgba(47, 191, 113, 0.18), transparent 28rem),
    linear-gradient(40deg, rgba(255, 183, 3, 0.16), transparent 22rem),
    var(--bg);
  color: var(--text);
}

a {
  color: inherit;
  text-decoration: none;
}

button,
input {
  font: inherit;
}

button {
  cursor: pointer;
}

.app-shell {
  min-height: 100vh;
}

.topbar {
  position: sticky;
  top: 0;
  z-index: 20;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 1rem;
  width: min(1180px, calc(100% - 2rem));
  min-height: 72px;
  margin: 0 auto;
  padding: 0.8rem 0;
  backdrop-filter: blur(16px);
}

.brand,
.nav-links,
.topbar-actions,
.hero-actions,
.challenge-meta,
.mini-game-actions,
.game-meta,
.game-card-footer,
.footer nav {
  display: flex;
  align-items: center;
}

.brand {
  gap: 0.7rem;
  font-weight: 800;
  letter-spacing: 0;
}

.brand-mark {
  display: grid;
  place-items: center;
  width: 38px;
  height: 38px;
  border-radius: var(--radius);
  background: var(--primary);
  color: var(--ink);
  box-shadow: 0 10px 30px rgba(47, 191, 113, 0.25);
}

.nav-links {
  gap: 1.25rem;
  color: var(--muted);
  font-weight: 600;
}

.nav-links a:hover {
  color: var(--text);
}

.topbar-actions {
  gap: 0.6rem;
}

.button,
.icon-button,
.category-tab {
  border: 1px solid var(--line);
  border-radius: var(--radius);
  transition: transform 160ms ease, border-color 160ms ease, background 160ms ease;
}

.button {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  min-height: 42px;
  padding: 0 1rem;
  font-weight: 800;
}

.button:hover,
.icon-button:hover,
.category-tab:hover {
  transform: translateY(-1px);
}

.button-primary {
  border-color: transparent;
  background: var(--primary);
  color: var(--ink);
}

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

.button-secondary,
.button-ghost {
  background: rgba(255, 255, 255, 0.06);
}

.button-card {
  width: 100%;
  margin-top: 1rem;
  background: var(--text);
  color: var(--bg);
}

.icon-button {
  display: grid;
  place-items: center;
  width: 42px;
  height: 42px;
  background: rgba(255, 255, 255, 0.06);
  color: var(--text);
}

.section {
  width: min(1180px, calc(100% - 2rem));
  margin: 0 auto;
  padding: 4.5rem 0;
}

.hero {
  display: flex;
  flex-direction: column;
  justify-content: center;
  align-items: center;
  text-align: center;
  min-height: calc(100vh - 72px);
  padding-top: 2.5rem;
}

.game-hero {
  display: grid;
  grid-template-columns: minmax(0, 1fr) minmax(220px, 0.28fr);
  gap: 1rem;
  align-items: end;
  padding-top: 3rem;
  padding-bottom: 2rem;
  border-bottom: 1px solid var(--line);
}

.game-hero h1 {
  max-width: 900px;
  margin-bottom: 1rem;
  font-size: clamp(3rem, 7vw, 6rem);
}

.game-summary {
  display: grid;
  justify-items: center;
  gap: 0.45rem;
  border: 1px solid var(--line);
  border-top: 5px solid var(--accent, var(--primary));
  border-radius: var(--radius);
  background: var(--surface);
  padding: 1.2rem;
  box-shadow: var(--shadow);
}

.game-summary span {
  display: grid;
  place-items: center;
  width: 92px;
  height: 92px;
  border-radius: 18px;
  background: var(--accent, var(--primary));
  color: var(--ink);
  font-size: 1.8rem;
  font-weight: 900;
}

.game-summary strong {
  font-size: 2rem;
}

.game-summary small {
  color: var(--muted);
  font-weight: 800;
}

.eyebrow {
  margin: 0 0 0.8rem;
  color: var(--secondary);
  font-size: 0.78rem;
  font-weight: 800;
  letter-spacing: 0.08em;
  text-transform: uppercase;
}

h1,
h2,
h3,
p {
  margin-top: 0;
}

h1 {
  max-width: 780px;
  margin-bottom: 1.2rem;
  font-size: clamp(3rem, 8vw, 6.9rem);
  line-height: 0.9;
  letter-spacing: 0;
}

h2 {
  margin-bottom: 0.8rem;
  font-size: clamp(2rem, 4vw, 3.7rem);
  line-height: 1;
}

h3 {
  margin-bottom: 0.5rem;
  font-size: 1.25rem;
}

.hero-copy,
.section-heading p,
.daily-card p,
.game-card p,
.teacher-copy p,
.insight-grid p {
  color: var(--muted);
  line-height: 1.65;
}

.hero-copy {
  max-width: 670px;
  margin: 0 auto;
  font-size: 1.15rem;
}

.hero-actions {
  justify-content: center;
  flex-wrap: wrap;
  gap: 0.75rem;
  margin: 2rem 0;
}

.hero-stats {
  display: grid;
  grid-template-columns: repeat(3, minmax(0, 1fr));
  gap: 0.8rem;
  max-width: 560px;
  margin: 0 auto;
}

.hero-stats div,
.daily-card,
.leaderboard-preview,
.game-card,
.insight-grid article,
.teacher-panel {
  border: 1px solid var(--line);
  border-radius: var(--radius);
  background: rgba(255, 255, 255, 0.055);
  box-shadow: var(--shadow);
}

.hero-stats div {
  padding: 1rem;
}

.hero-stats dt {
  font-size: 1.7rem;
  font-weight: 800;
}

.hero-stats dd {
  margin: 0.2rem 0 0;
  color: var(--muted);
}

.hero-board {
  overflow: hidden;
  border: 1px solid var(--line);
  border-radius: 18px;
  background: linear-gradient(180deg, var(--surface), var(--surface-2));
  box-shadow: var(--shadow);
}

.board-header,
.board-footer {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 1.2rem;
}

.board-header strong {
  display: grid;
  place-items: center;
  width: 58px;
  height: 58px;
  border-radius: 50%;
  background: var(--secondary);
  color: var(--ink);
  font-size: 1.35rem;
}

.number-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 0.75rem;
  padding: 1.2rem;
}

.number-grid button {
  aspect-ratio: 1;
  border: 0;
  border-radius: var(--radius);
  background: var(--primary);
  color: var(--ink);
  font-size: 1.55rem;
  font-weight: 900;
  animation: pop 640ms ease both;
  animation-delay: var(--delay);
}

@keyframes pop {
  from {
    opacity: 0;
    transform: scale(0.9);
  }
}

.daily-band {
  width: 100%;
  padding-right: max(1rem, calc((100vw - 1180px) / 2));
  padding-left: max(1rem, calc((100vw - 1180px) / 2));
  background: rgba(255, 255, 255, 0.04);
}

.section-heading {
  max-width: 760px;
  margin-bottom: 2rem;
}

.section-heading.compact {
  margin-bottom: 1.2rem;
}

.section-heading.compact h2 {
  font-size: 1.6rem;
}

.daily-layout {
  display: grid;
  grid-template-columns: minmax(0, 1.2fr) minmax(300px, 0.8fr);
  gap: 1rem;
}

.daily-card,
.leaderboard-preview,
.teacher-panel {
  padding: 1.2rem;
  background: var(--surface);
}

.play-section {
  border-top: 1px solid var(--line);
}

.dedicated-play {
  padding-top: 2rem;
}

.play-layout {
  display: grid;
  grid-template-columns: minmax(0, 1fr) minmax(240px, 0.32fr);
  gap: 1rem;
}

.game-shell,
.player-panel {
  border: 1px solid var(--line);
  border-radius: var(--radius);
  background: var(--surface);
  box-shadow: var(--shadow);
}

.game-shell {
  min-height: 520px;
  padding: 1rem;
  border-top: 5px solid var(--accent, var(--primary));
}

.player-panel {
  display: grid;
  align-content: start;
  gap: 0.8rem;
  padding: 1rem;
}

.player-panel div {
  display: flex;
  justify-content: space-between;
  gap: 1rem;
  padding: 0.9rem;
  border-radius: var(--radius);
  background: var(--surface-2);
}

.player-panel span {
  color: var(--muted);
  font-weight: 700;
}

.play-card {
  display: grid;
  gap: 1rem;
  min-height: 480px;
  align-content: center;
  border-radius: var(--radius);
  background:
    linear-gradient(135deg, color-mix(in srgb, var(--accent, var(--primary)), transparent 84%), transparent),
    var(--surface-2);
  padding: clamp(1rem, 3vw, 2rem);
}

.play-card-top {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 1rem;
  margin-bottom: 0.25rem;
  padding-bottom: 1rem;
  border-bottom: 1px solid var(--line);
}

.play-card-top div {
  display: grid;
  gap: 0.25rem;
}

.play-card-top span {
  color: var(--secondary);
  font-size: 0.76rem;
  font-weight: 900;
  letter-spacing: 0.08em;
  text-transform: uppercase;
}

.play-card-top strong {
  font-size: 1.15rem;
}

.play-card-top a {
  min-height: 38px;
  border: 1px solid var(--line);
  border-radius: var(--radius);
  padding: 0.55rem 0.75rem;
  background: var(--surface);
  color: var(--text);
  font-weight: 800;
  white-space: nowrap;
}

.play-prompt {
  font-size: clamp(2.3rem, 8vw, 5.6rem);
  font-weight: 900;
  line-height: 1;
  letter-spacing: 0;
}

.play-actions,
.tile-row,
.slot-row,
.direction-pad {
  display: flex;
  align-items: center;
  flex-wrap: wrap;
  gap: 0.7rem;
}

.play-actions {
  justify-content: space-between;
}

.game-action,
.number-tile,
.operator-tile,
.slot-row span,
.prime-grid button,
.maze-grid button,
.memory-grid button,
.direction-pad button {
  border: 1px solid var(--line);
  border-radius: var(--radius);
  background: var(--surface);
  color: var(--text);
  font-weight: 900;
}

.game-action,
.number-tile,
.operator-tile {
  min-height: 48px;
  padding: 0 1rem;
}

.game-action.primary {
  border-color: transparent;
  background: var(--primary);
  color: var(--ink);
}

.number-tile,
.operator-tile {
  min-width: 58px;
  font-size: 1.2rem;
}

.number-tile:disabled {
  opacity: 0.35;
  cursor: not-allowed;
}

.target-line {
  display: flex;
  align-items: center;
  flex-wrap: wrap;
  gap: 0.75rem;
  color: var(--muted);
  font-weight: 800;
}

.target-line strong {
  display: inline-grid;
  place-items: center;
  min-width: 58px;
  min-height: 44px;
  border-radius: var(--radius);
  background: var(--secondary);
  color: var(--ink);
  padding: 0 0.7rem;
  font-size: 1.35rem;
}

.expression {
  min-height: 68px;
  border: 1px dashed var(--line);
  border-radius: var(--radius);
  padding: 1rem;
  color: var(--muted);
  font-size: 1.5rem;
  font-weight: 900;
}

.slot-row span {
  display: grid;
  place-items: center;
  width: 70px;
  height: 64px;
  background: var(--bg);
  font-size: 1.5rem;
}

.memory-grid,
.prime-grid,
.maze-grid,
.grid-2048,
.sudoku-grid {
  display: grid;
  gap: 0.6rem;
}

.memory-grid,
.grid-2048,
.sudoku-grid {
  grid-template-columns: repeat(4, minmax(0, 1fr));
}

.prime-grid,
.maze-grid {
  grid-template-columns: repeat(3, minmax(0, 1fr));
}

.memory-grid button,
.prime-grid button,
.maze-grid button,
.grid-2048 div,
.sudoku-grid input {
  display: grid;
  place-items: center;
  aspect-ratio: 1;
  min-height: 58px;
  font-size: 1.3rem;
}

.sudoku-grid input {
  border: 1px solid var(--line);
  border-radius: var(--radius);
  background: var(--bg);
  color: var(--text);
  text-align: center;
  font-weight: 900;
  -moz-appearance: textfield;
}

.sudoku-grid input::-webkit-outer-spin-button,
.sudoku-grid input::-webkit-inner-spin-button {
  -webkit-appearance: none;
  margin: 0;
}

.sudoku-grid input[readonly] {
  background: var(--surface-2);
  color: var(--primary);
  border-color: transparent;
}

.memory-grid button.is-revealed,
.memory-grid button.is-selected,
.prime-grid button.is-selected,
.maze-grid button.is-selected,
.grid-2048 div.filled {
  border-color: transparent;
  background: var(--primary);
  color: var(--ink);
}

.grid-2048 div {
  border-radius: var(--radius);
  background: var(--bg);
  font-size: 1.5rem;
  font-weight: 900;
}

.direction-pad {
  justify-content: center;
}

.clues {
  display: grid;
  gap: 0.45rem;
  margin: 0;
  color: var(--muted);
  line-height: 1.5;
}

.logic-grid {
  display: grid;
  gap: 0.75rem;
}

.logic-grid label {
  display: grid;
  grid-template-columns: 90px minmax(0, 1fr);
  align-items: center;
  gap: 0.75rem;
}

.logic-grid select {
  min-height: 46px;
  border: 1px solid var(--line);
  border-radius: var(--radius);
  background: var(--bg);
  color: var(--text);
  padding: 0 0.75rem;
  font: inherit;
}

.card-kicker {
  color: var(--secondary);
  font-weight: 800;
}

.challenge-meta {
  flex-wrap: wrap;
  gap: 0.6rem;
  margin: 1rem 0;
}

.challenge-meta span,
.game-meta span,
.game-card-footer span {
  border-radius: 999px;
  background: var(--surface-2);
  color: var(--muted);
  padding: 0.42rem 0.62rem;
  font-size: 0.82rem;
  font-weight: 700;
}

.mini-game {
  display: grid;
  gap: 0.9rem;
  margin-top: 1rem;
  padding: 1rem;
  border-radius: var(--radius);
  background: var(--surface-2);
}

.prompt {
  font-size: clamp(2.2rem, 8vw, 4.2rem);
  font-weight: 900;
  letter-spacing: 0;
}

.answer-row {
  display: grid;
  gap: 0.4rem;
  color: var(--muted);
  font-weight: 700;
}

.answer-row input {
  min-height: 48px;
  border: 1px solid var(--line);
  border-radius: var(--radius);
  background: var(--bg);
  color: var(--text);
  padding: 0 0.8rem;
  font-size: 1.1rem;
}

.mini-game-actions {
  justify-content: space-between;
  gap: 1rem;
  flex-wrap: wrap;
}

.leaderboard-list {
  display: grid;
  gap: 0.7rem;
  padding: 0;
  margin: 0;
  list-style: none;
}

.leaderboard-list li {
  display: grid;
  grid-template-columns: 38px 1fr auto;
  gap: 0.75rem;
  align-items: center;
  padding: 0.75rem;
  border-radius: var(--radius);
  background: var(--surface-2);
}

.rank {
  display: grid;
  place-items: center;
  width: 32px;
  height: 32px;
  border-radius: 50%;
  background: var(--secondary);
  color: var(--ink);
  font-weight: 900;
}

.leaderboard-list small {
  display: block;
  margin-top: 0.1rem;
  color: var(--muted);
}

.category-tabs {
  display: flex;
  flex-wrap: wrap;
  gap: 0.6rem;
  margin-bottom: 1.2rem;
}

.category-tab {
  min-height: 40px;
  background: var(--surface);
  color: var(--text);
  padding: 0 0.9rem;
  font-weight: 800;
}

.category-tab.is-active {
  border-color: transparent;
  background: var(--secondary);
  color: var(--ink);
}

.game-grid {
  display: grid;
  grid-template-columns: repeat(4, minmax(0, 1fr));
  gap: 1rem;
}

.game-card {
  overflow: hidden;
  background: var(--surface);
}

.game-art {
  display: grid;
  place-items: center;
  min-height: 150px;
  background:
    linear-gradient(135deg, color-mix(in srgb, var(--accent), transparent 18%), transparent),
    var(--surface-2);
}

.game-art span {
  display: grid;
  place-items: center;
  width: 86px;
  height: 86px;
  border-radius: 18px;
  background: var(--accent);
  color: var(--ink);
  font-size: 1.6rem;
  font-weight: 900;
}

.game-card-body {
  padding: 1rem;
}

.game-meta,
.game-card-footer {
  justify-content: space-between;
  gap: 0.5rem;
}

.game-meta {
  margin-bottom: 0.9rem;
}

.insights-section,
.teacher-section {
  border-top: 1px solid var(--line);
}

.insight-grid {
  display: grid;
  grid-template-columns: repeat(3, minmax(0, 1fr));
  gap: 1rem;
}

.insight-grid article {
  padding: 1.2rem;
  background: var(--surface);
}

.insight-icon {
  display: grid;
  place-items: center;
  width: 46px;
  height: 46px;
  margin-bottom: 1rem;
  border-radius: var(--radius);
  background: var(--primary);
  color: var(--ink);
  font-weight: 900;
}

.teacher-section {
  display: grid;
  grid-template-columns: minmax(0, 1fr) minmax(300px, 0.6fr);
  gap: 1rem;
  align-items: center;
}

.teacher-panel {
  display: grid;
  gap: 0.8rem;
}

.teacher-panel div {
  display: flex;
  justify-content: space-between;
  gap: 1rem;
  padding: 0.85rem;
  border-radius: var(--radius);
  background: var(--surface-2);
}

.teacher-panel span {
  color: var(--muted);
}

.footer {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 1rem;
  width: min(1180px, calc(100% - 2rem));
  margin: 0 auto;
  padding: 2rem 0;
  border-top: 1px solid var(--line);
  color: var(--muted);
}

.footer > span {
  color: var(--text);
  font-weight: 900;
}

.footer nav {
  gap: 1rem;
  flex-wrap: wrap;
}

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

@media (max-width: 980px) {
  .nav-links {
    display: none;
  }

  .hero,
  .game-hero,
  .daily-layout,
  .play-layout,
  .teacher-section {
    grid-template-columns: 1fr;
  }

  .hero {
    min-height: auto;
  }

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

@media (max-width: 640px) {
  .topbar {
    width: min(100% - 1rem, 1180px);
  }

  .button-ghost {
    display: none;
  }

  .section {
    width: min(100% - 1rem, 1180px);
    padding: 3rem 0;
  }

  .daily-band {
    width: 100%;
    padding-right: 0.5rem;
    padding-left: 0.5rem;
  }

  h1 {
    font-size: 3.1rem;
  }

  .hero-stats,
  .insight-grid,
  .game-grid {
    grid-template-columns: 1fr;
  }

  .footer {
    align-items: flex-start;
    flex-direction: column;
  }
}