:root {
  color-scheme: light;
  --page: #f2f5f8;
  --surface: #ffffff;
  --ink: #172033;
  --muted: #5f6b7c;
  --line: #d9e0e8;
  --board: #1769d2;
  --board-dark: #0d4fa8;
  --red: #db3146;
  --red-dark: #a8152a;
  --yellow: #f6c945;
  --yellow-dark: #9a6f00;
  --focus: #6b3df5;
  --shadow: 0 16px 40px rgba(23, 32, 51, 0.12);
}

* {
  box-sizing: border-box;
}

body {
  min-width: 0;
  min-height: 100vh;
  margin: 0;
  overflow-x: hidden;
  color: var(--ink);
  background: var(--page);
  font-family: Inter, ui-sans-serif, system-ui, -apple-system, BlinkMacSystemFont, "Segoe UI", sans-serif;
  line-height: 1.5;
}

button,
input {
  font: inherit;
}

button {
  touch-action: manipulation;
}

[hidden] {
  display: none !important;
}

.game-shell {
  width: min(100% - 2rem, 48rem);
  margin-inline: auto;
  padding-block: clamp(1.5rem, 4vw, 3.5rem);
}

.game-header {
  margin-bottom: 1.5rem;
  text-align: center;
}

.eyebrow {
  margin: 0 0 0.35rem;
  color: var(--board-dark);
  font-size: 0.78rem;
  font-weight: 800;
  letter-spacing: 0.12em;
  text-transform: uppercase;
}

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

h1 {
  margin-bottom: 0.55rem;
  font-size: clamp(2.25rem, 8vw, 4rem);
  line-height: 1;
  letter-spacing: -0.045em;
}

h2 {
  margin-bottom: 1rem;
  font-size: clamp(1.25rem, 4vw, 1.6rem);
}

.instructions {
  max-width: 42rem;
  margin: 0 auto;
  color: var(--muted);
  font-size: 0.98rem;
}

.setup-card,
.game-area {
  border: 1px solid var(--line);
  border-radius: 1.25rem;
  background: var(--surface);
  box-shadow: var(--shadow);
}

.setup-card {
  padding: clamp(1.1rem, 4vw, 2rem);
}

.form-grid {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 1rem;
  margin-bottom: 1.25rem;
}

.field-group {
  min-width: 0;
}

.field-group label {
  display: block;
  margin-bottom: 0.4rem;
  font-weight: 750;
}

.field-group input {
  width: 100%;
  min-height: 2.85rem;
  padding: 0.65rem 0.75rem;
  border: 1px solid #aeb9c7;
  border-radius: 0.65rem;
  color: var(--ink);
  background: #fff;
}

.field-group input::placeholder {
  color: #788496;
}

.player-color {
  display: inline-flex;
  align-items: center;
  gap: 0.4rem;
  margin-top: 0.5rem;
  color: var(--muted);
  font-size: 0.82rem;
  font-weight: 700;
}

.color-swatch {
  width: 0.8rem;
  height: 0.8rem;
  border: 1px solid rgba(23, 32, 51, 0.25);
  border-radius: 50%;
}

.color-swatch.red {
  background: var(--red);
}

.color-swatch.yellow {
  background: var(--yellow);
}

.form-error {
  margin-bottom: 0.8rem;
  color: #a8152a;
  font-weight: 700;
}

.primary-button,
.secondary-button {
  min-height: 2.75rem;
  padding: 0.65rem 1rem;
  border-radius: 0.7rem;
  font-weight: 800;
  cursor: pointer;
}

.primary-button {
  border: 1px solid var(--board-dark);
  color: #fff;
  background: var(--board-dark);
}

.primary-button:hover {
  background: #083f88;
}

.secondary-button {
  border: 1px solid #aeb9c7;
  color: var(--ink);
  background: #fff;
}

.secondary-button:hover {
  background: #f5f7fa;
}

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

.game-area {
  padding: clamp(0.75rem, 3vw, 1.5rem);
}

.players {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 0.75rem;
}

.player-card {
  min-width: 0;
  padding: 0.8rem;
  border: 2px solid transparent;
  border-radius: 0.85rem;
  background: #f5f7fa;
}

.player-card.active {
  border-color: var(--ink);
  background: #fff;
}

.player-card .player-label {
  display: block;
  color: var(--muted);
  font-size: 0.72rem;
  font-weight: 800;
  letter-spacing: 0.08em;
  text-transform: uppercase;
}

.player-card strong {
  display: block;
  overflow-wrap: anywhere;
  font-size: clamp(1rem, 4vw, 1.25rem);
  line-height: 1.25;
}

.game-status {
  min-height: 3.1rem;
  margin: 1rem 0;
  padding: 0.75rem 1rem;
  border-left: 4px solid var(--board);
  border-radius: 0.5rem;
  background: #eef5ff;
  font-weight: 800;
  text-align: center;
}

.game-status.is-error {
  border-left-color: var(--red);
  background: #fff0f2;
}

.game-status.is-complete {
  border-left-color: #21845a;
  background: #edf9f3;
}

.game-stage {
  width: min(100%, 39rem);
  margin-inline: auto;
}

.column-controls {
  display: grid;
  grid-template-columns: repeat(7, minmax(0, 1fr));
  gap: clamp(0.15rem, 1vw, 0.45rem);
  margin-bottom: 0.55rem;
  padding-inline: clamp(0.45rem, 1.5vw, 0.85rem);
}

.column-controls button {
  min-width: 0;
  min-height: 2.75rem;
  border: 1px solid #9ca9b9;
  border-radius: 0.55rem;
  color: var(--board-dark);
  background: #fff;
  font-weight: 850;
  cursor: pointer;
}

.column-controls button:hover:not(:disabled) {
  border-color: var(--board-dark);
  color: #fff;
  background: var(--board-dark);
}

.column-controls button:disabled {
  cursor: not-allowed;
  opacity: 0.45;
}

.board {
  display: grid;
  grid-template-rows: repeat(6, minmax(0, 1fr));
  width: 100%;
  aspect-ratio: 7 / 6;
  padding: clamp(0.45rem, 1.5vw, 0.85rem);
  border: 2px solid var(--board-dark);
  border-radius: clamp(0.75rem, 3vw, 1.2rem);
  background: var(--board);
  box-shadow: inset 0 -0.45rem 0 var(--board-dark), 0 0.65rem 1.4rem rgba(13, 79, 168, 0.22);
  gap: clamp(0.22rem, 1vw, 0.55rem);
}

.board-row {
  display: grid;
  grid-template-columns: repeat(7, minmax(0, 1fr));
  gap: clamp(0.22rem, 1vw, 0.55rem);
  min-height: 0;
}

.cell {
  display: grid;
  min-width: 0;
  min-height: 0;
  aspect-ratio: 1;
  place-items: center;
  overflow: hidden;
  border: 2px solid rgba(13, 79, 168, 0.72);
  border-radius: 50%;
  background: #f7f9fc;
  box-shadow: inset 0 0.22rem 0.45rem rgba(23, 32, 51, 0.18);
}

.token {
  display: grid;
  width: 88%;
  aspect-ratio: 1;
  place-items: center;
  border: 2px solid rgba(23, 32, 51, 0.34);
  border-radius: 50%;
  font-size: clamp(0.56rem, 2.2vw, 0.9rem);
  font-weight: 900;
  letter-spacing: -0.04em;
}

.token.player-one {
  color: #fff;
  background: var(--red);
  box-shadow: inset 0 -0.35rem 0 var(--red-dark);
}

.token.player-two {
  color: #3f3100;
  background: var(--yellow);
  box-shadow: inset 0 -0.35rem 0 var(--yellow-dark);
}

.cell.winning {
  outline: 4px solid #fff;
  outline-offset: -5px;
  box-shadow: 0 0 0 3px var(--ink), inset 0 0.22rem 0.45rem rgba(23, 32, 51, 0.18);
}

.game-actions {
  display: flex;
  flex-wrap: wrap;
  justify-content: center;
  gap: 0.65rem;
  margin-top: 1.25rem;
}

@media (max-width: 34rem) {
  .game-shell {
    width: min(100% - 1rem, 48rem);
    padding-block: 1rem;
  }

  .game-header {
    margin-bottom: 1rem;
  }

  .instructions {
    font-size: 0.9rem;
  }

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

  .game-area {
    border-radius: 0.9rem;
  }

  .player-card {
    padding: 0.65rem;
  }

  .game-status {
    margin-block: 0.75rem;
    padding: 0.6rem 0.7rem;
    font-size: 0.92rem;
  }

  .column-controls button {
    min-height: 2.65rem;
    padding-inline: 0;
  }
}

@media (prefers-reduced-motion: reduce) {
  *,
  *::before,
  *::after {
    scroll-behavior: auto !important;
  }
}