:root {
  color-scheme: light;
  --ink: #222;
  --muted: #6f7275;
  --line: #dedede;
  --soft: #f6f7f8;
  --blue: #267cb9;
  --blue-dark: #075f96;
  --good: #138a50;
  --bad: #c63d46;
  --red: #ed2134;
  --purple: #64369b;
  --green: #00a957;
  --shadow: 0 18px 50px rgb(24 31 38 / 12%);
}

* {
  box-sizing: border-box;
}

[hidden] {
  display: none !important;
}

body {
  margin: 0;
  min-width: 320px;
  background: #fff;
  color: var(--ink);
  font: 14px/1.5 "Noto Sans", "Helvetica Neue", Helvetica, Arial, sans-serif;
}

button {
  font: inherit;
}

button:focus-visible,
a:focus-visible {
  outline: 3px solid rgb(38 124 185 / 30%);
  outline-offset: 3px;
}

.page-shell {
  width: min(1280px, calc(100% - 48px));
  margin: 0 auto;
  padding: 40px 0 72px;
}

.site-header,
.game-heading-row,
.history-heading-row,
.modal-heading,
.result-actions {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 24px;
}

.site-header {
  padding-bottom: 24px;
}

.site-header h1 {
  margin: 6px 0 2px;
  font-size: clamp(2rem, 4vw, 3rem);
  line-height: 1;
  letter-spacing: -0.04em;
}

.site-header p,
.copy-status {
  margin: 0;
  color: var(--muted);
}

.home-link {
  color: var(--blue);
  text-decoration: none;
}

.home-link:hover {
  color: var(--blue-dark);
  text-decoration: underline;
}

.button {
  min-height: 42px;
  padding: 9px 16px;
  border: 1px solid var(--line);
  border-radius: 8px;
  cursor: pointer;
  font-weight: 700;
}

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

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

.button-secondary {
  background: #fff;
  color: #3d4246;
}

.button-secondary:hover {
  border-color: #acb0b3;
  background: var(--soft);
}

.setup-panel {
  display: flex;
  align-items: flex-end;
  flex-wrap: wrap;
  gap: 18px 28px;
  padding: 16px 18px;
  border: 0;
  border-radius: 0;
  background: #e9f7ee;
}

.control-group {
  min-width: 0;
  margin: 0;
  padding: 0;
  border: 0;
}

.control-group legend {
  margin-bottom: 7px;
  color: #4c5155;
  font-size: 12px;
  font-weight: 700;
  letter-spacing: 0.06em;
  text-transform: uppercase;
}

.segmented-control {
  display: inline-flex;
  max-width: 100%;
  gap: 2px;
  padding: 0;
  border: 0;
  border-radius: 0;
  background: transparent;
}

.segmented-control button {
  min-height: 34px;
  padding: 6px 12px;
  border: 0;
  border-radius: 5px;
  background: transparent;
  color: #555b60;
  cursor: pointer;
  white-space: nowrap;
}

.segmented-control button:hover {
  background: #edf3f7;
}

.segmented-control button[aria-pressed="true"] {
  background: #e4f0f8;
  color: #145f91;
  font-weight: 700;
  box-shadow: inset 0 0 0 1px rgb(38 124 185 / 18%);
}

.candidate-settings,
.difference-settings {
  position: relative;
  align-self: flex-end;
}

.slider-settings-card {
  position: absolute;
  z-index: 10;
  top: calc(100% + 10px);
  left: 0;
  width: 310px;
  padding: 16px;
  border: 0;
  border-radius: 9px;
  background: #fff;
  box-shadow: var(--shadow);
}

.slider-heading {
  display: flex;
  align-items: center;
  justify-content: space-between;
  margin-bottom: 13px;
  font-weight: 700;
}

.slider-heading output {
  color: var(--blue-dark);
}

.slider-settings-card input[type="range"] {
  --slider-progress: 100%;
  appearance: none;
  width: 100%;
  height: 14px;
  margin: 0;
  border-radius: 999px;
  background: linear-gradient(
    to right,
    #1688f8 0,
    #1688f8 var(--slider-progress),
    #eceeef var(--slider-progress),
    #eceeef 100%
  );
  cursor: pointer;
}

.slider-settings-card input[type="range"]::-webkit-slider-thumb {
  appearance: none;
  width: 24px;
  height: 24px;
  border: 0;
  border-radius: 50%;
  background: #fff;
  box-shadow: 0 1px 5px rgb(20 28 35 / 28%);
}

.slider-settings-card input[type="range"]::-moz-range-thumb {
  width: 24px;
  height: 24px;
  border: 0;
  border-radius: 50%;
  background: #fff;
  box-shadow: 0 1px 5px rgb(20 28 35 / 28%);
}

.slider-labels {
  display: flex;
  justify-content: space-between;
  margin-top: 3px;
  padding: 0 12px;
  color: var(--muted);
  font-size: 10px;
  text-align: center;
}

.slider-labels span {
  display: flex;
  width: 0;
  justify-content: center;
  white-space: nowrap;
}

.game-panel,
.history-panel {
  margin-top: 24px;
  padding: 24px;
  border: 1px solid var(--line);
  border-radius: 14px;
  background: #fff;
  box-shadow: 0 4px 20px rgb(20 28 35 / 5%);
}

.game-panel {
  padding: 16px 0 0;
  border: 0;
  border-radius: 0;
  box-shadow: none;
}

.setup-actions {
  display: flex;
  align-self: flex-end;
  align-items: center;
  gap: 18px;
  margin: 0 0 4px auto;
}

.toolbar-link {
  align-self: flex-end;
  min-height: 34px;
  margin: 0;
  padding: 5px 0;
  border: 0;
  border-bottom: 1px solid currentColor;
  background: transparent;
  color: var(--blue);
  cursor: pointer;
  font-weight: 700;
}

.toolbar-link:hover {
  color: var(--blue-dark);
}

.color-settings {
  position: relative;
}

.color-settings-card {
  position: absolute;
  z-index: 10;
  top: calc(100% + 10px);
  right: 0;
  width: 250px;
  padding: 15px;
  border: 0;
  border-radius: 8px;
  background: #fff;
  box-shadow: var(--shadow);
}

.color-settings-card strong {
  display: block;
  margin-bottom: 10px;
}

.colorblind-toggle {
  display: inline-flex;
  min-height: 38px;
  align-items: center;
  gap: 8px;
  margin: 0;
  color: #4c5155;
  cursor: pointer;
  font-weight: 700;
  white-space: nowrap;
}

.colorblind-toggle input {
  width: 16px;
  height: 16px;
  margin: 0;
  accent-color: var(--blue);
}

.game-heading-row {
  align-items: flex-start;
}

.game-title-row {
  display: flex;
  align-items: center;
  gap: 9px;
}

.review-controls {
  display: flex;
  align-items: center;
  gap: 6px;
}

.game-title-button {
  min-height: 28px;
  padding: 3px 8px;
  border: 1px solid var(--line);
  border-radius: 4px;
  background: #fff;
  color: var(--muted);
  cursor: pointer;
  font-size: 11px;
  font-weight: 700;
  line-height: 1.3;
}

.game-title-button:hover {
  border-color: #acb0b3;
  color: var(--ink);
}

.eyebrow {
  margin: 0 0 5px;
  color: var(--muted);
  font-size: 11px;
  font-weight: 700;
  letter-spacing: 0.1em;
  text-transform: uppercase;
}

.game-heading-row h2,
.history-heading-row h2,
.modal-card h2 {
  margin: 0;
  color: var(--ink);
}

.stats {
  display: flex;
  gap: 10px;
  margin: 0;
}

.stats > div {
  min-width: 76px;
  padding: 4px 12px;
  text-align: center;
}

.stats dt {
  color: var(--muted);
  font-size: 10px;
  font-weight: 700;
  letter-spacing: 0.07em;
  text-transform: uppercase;
}

.stats dd {
  margin: 1px 0 0;
  font-size: 18px;
  font-variant-numeric: tabular-nums;
  font-weight: 700;
}

.feedback {
  min-height: 24px;
  margin: 10px 0 2px;
  font-weight: 700;
}

.feedback.is-correct {
  color: var(--good);
}

.feedback.is-wrong {
  color: var(--bad);
}

.photo-layout {
  display: flex;
  gap: 16px;
  padding: 12px 4px 12px;
  overflow-x: auto;
  overscroll-behavior-inline: contain;
  scrollbar-color: #bec2c5 transparent;
}

.board-column {
  flex: 0 0 150px;
}

.board-column h3 {
  min-height: 18px;
  margin: 0 0 8px;
  color: var(--muted);
  font-size: 11px;
  letter-spacing: 0.05em;
  text-align: center;
  text-transform: uppercase;
}

.mobile-board-heading {
  display: none;
}

.column-cards {
  display: flex;
  min-height: 320px;
  flex-direction: column;
  gap: 10px;
}

.prompt-column .column-cards {
  justify-content: center;
}

.set-card {
  display: grid;
  width: 150px;
  aspect-ratio: 3 / 2;
  place-items: center;
  overflow: hidden;
  border: 1px solid #d8dadd;
  border-radius: 9px;
  background: #fff;
  box-shadow: 0 2px 6px rgb(20 28 35 / 6%);
}

.set-card svg {
  display: block;
  width: 100%;
  height: 100%;
}

.candidate-button {
  display: block;
  margin: 0;
  padding: 0;
  border: 0;
  border-radius: 10px;
  background: transparent;
  cursor: pointer;
}

.candidate-button:hover .set-card {
  border-color: var(--blue);
  box-shadow: 0 6px 18px rgb(38 124 185 / 18%);
  transform: translateY(-1px);
}

.candidate-button.is-correct .set-card {
  border-color: var(--good);
  box-shadow: 0 0 0 3px rgb(19 138 80 / 20%);
}

.candidate-button.is-wrong .set-card {
  border-color: var(--bad);
  box-shadow: 0 0 0 3px rgb(198 61 70 / 18%);
  animation: shake 180ms ease-in-out;
}

.candidate-button:disabled {
  cursor: default;
}

.candidate-button:disabled:not(.is-correct):not(.is-wrong) {
  opacity: 0.72;
}

.embedded-given {
  position: relative;
  width: 150px;
  border-radius: 10px;
}

.embedded-given .set-card {
  border: 2px solid var(--good);
  background: #f1fbf5;
  box-shadow: 0 0 0 3px rgb(19 138 80 / 20%);
}

.history-panel {
  padding: 0;
  border: 0;
  border-radius: 0;
  background: transparent;
  box-shadow: none;
}

.history-heading-row {
  margin-bottom: 8px;
}

.history-heading-row h2 {
  font-size: 18px;
}

.history-heading-row span {
  color: var(--muted);
}

.history-list {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
  gap: 0 24px;
}

.history-item {
  display: flex;
  align-items: center;
  gap: 12px;
  padding: 10px 0;
  border: 0;
  border-bottom: 1px solid #eceeef;
  border-radius: 0;
  background: transparent;
}

.history-meta {
  flex: 0 0 56px;
  color: var(--muted);
  font-size: 11px;
  font-variant-numeric: tabular-nums;
}

.history-meta strong {
  display: block;
  color: #3e4347;
  font-size: 12px;
}

.history-cards {
  display: flex;
  flex: 1 1 auto;
  min-width: 0;
  gap: 5px;
}

.history-cards .set-card,
.set-card.is-compact {
  width: min(72px, 22vw);
  border-radius: 5px;
}

.history-cards .set-card {
  width: auto;
  max-width: 72px;
  flex: 1 1 0;
}

.modal {
  width: min(760px, calc(100% - 28px));
  max-height: min(88vh, 920px);
  padding: 0;
  border: 0;
  border-radius: 14px;
  background: transparent;
  color: var(--ink);
  box-shadow: var(--shadow);
}

.modal::backdrop {
  background: rgb(20 25 29 / 55%);
  backdrop-filter: blur(2px);
}

.modal-card {
  max-height: min(88vh, 920px);
  padding: 26px;
  overflow-y: auto;
  border-radius: 14px;
  background: #fff;
}

.modal-heading {
  align-items: flex-start;
}

.modal-card h2 {
  font-size: 25px;
  letter-spacing: 0.04em;
  text-transform: uppercase;
}

.modal-card h3 {
  margin: 26px 0 12px;
  color: #454a4e;
  font-size: 14px;
}

.modal-card h4 {
  margin: 0 0 5px;
}

.modal-card p,
.modal-card ul {
  margin: 12px 0;
  color: #4f5458;
}

.icon-button {
  width: 38px;
  height: 38px;
  border: 0;
  border-radius: 50%;
  background: transparent;
  color: #666;
  cursor: pointer;
  font-size: 26px;
  line-height: 1;
}

.icon-button:hover {
  background: var(--soft);
}

.feature-guide {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 14px;
}

.feature-block {
  padding: 12px;
  border: 1px solid var(--line);
  border-radius: 9px;
}

.feature-block h4 {
  text-transform: capitalize;
}

.feature-values {
  display: flex;
  gap: 7px;
}

.feature-value {
  min-width: 0;
  flex: 1;
  color: var(--muted);
  font-size: 11px;
  text-align: center;
  text-transform: capitalize;
}

.feature-value .set-card {
  width: 100%;
  margin-bottom: 4px;
}

.example-list {
  display: grid;
  gap: 12px;
}

.example-set {
  display: flex;
  align-items: center;
  gap: 12px;
}

.example-cards {
  display: flex;
  flex: 0 0 auto;
  gap: 7px;
}

.example-cards .set-card {
  width: 92px;
}

.example-set p {
  margin: 0;
  font-size: 12px;
}

.modal-done {
  width: 100%;
  margin-top: 14px;
}

.result-modal {
  width: min(540px, calc(100% - 28px));
}

.result-stats {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 9px;
  margin: 20px 0;
}

.result-stat {
  padding: 12px;
  border: 1px solid var(--line);
  border-radius: 9px;
  background: var(--soft);
  text-align: center;
}

.result-stat span {
  display: block;
  color: var(--muted);
  font-size: 10px;
  font-weight: 700;
  letter-spacing: 0.06em;
  text-transform: uppercase;
}

.result-stat strong {
  display: block;
  margin-top: 2px;
  font-size: 20px;
  font-variant-numeric: tabular-nums;
}

.share-preview {
  max-height: 250px;
  margin: 0;
  padding: 14px;
  overflow: auto;
  border: 1px solid var(--line);
  border-radius: 9px;
  background: #f7f8f9;
  color: #303438;
  font: 12px/1.55 Monaco, "Bitstream Vera Sans Mono", "Lucida Console", Terminal,
    Consolas, "Liberation Mono", "DejaVu Sans Mono", "Courier New", monospace;
  white-space: pre-wrap;
}

.copy-status {
  min-height: 21px;
  margin: 8px 0 4px;
  color: var(--good);
  font-weight: 700;
}

.result-actions {
  justify-content: flex-end;
}

@keyframes shake {
  0%, 100% { transform: translateX(0); }
  35% { transform: translateX(-4px); }
  70% { transform: translateX(4px); }
}

@media (max-width: 760px) {
  .page-shell {
    width: min(100% - 28px, 1280px);
    padding-top: 22px;
  }

  .game-heading-row {
    display: block;
  }

  .stats {
    margin-top: 16px;
  }

  .stats > div {
    min-width: 0;
    flex: 1;
  }

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

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

@media (max-width: 520px) {
  .site-header {
    align-items: flex-start;
  }

  .site-header .button {
    padding-inline: 11px;
  }

  .setup-panel {
    padding: 16px;
  }

  .game-panel {
    padding: 14px 0 0;
  }

  .setup-panel {
    display: grid;
  }

  .setup-actions {
    width: 100%;
    margin-left: 0;
  }

  .color-settings-card {
    right: auto;
    left: 0;
  }

  .slider-settings-card {
    width: min(310px, calc(100vw - 60px));
  }

  .segmented-control {
    display: flex;
    width: 100%;
  }

  .segmented-control button {
    min-width: 0;
    flex: 1 1 auto;
    padding-inline: 6px;
    font-size: 13px;
  }

  .photo-layout {
    display: grid;
    grid-template-columns: repeat(2, minmax(0, 1fr));
    gap: 14px 8px;
    padding-inline: 0;
    overflow-x: visible;
  }

  .board-column {
    width: auto;
    min-width: 0;
  }

  .board-column h3 {
    display: none;
  }

  .mobile-board-heading {
    display: block;
    grid-column: 1 / -1;
    min-height: 0;
    margin: 0 0 -8px;
    color: var(--muted);
    font-size: 11px;
    letter-spacing: 0.05em;
    text-align: center;
    text-transform: uppercase;
  }

  .column-cards {
    min-height: 0;
    gap: 8px;
  }

  .prompt-column .column-cards {
    justify-content: flex-start;
  }

  .answers-column {
    grid-column: 1 / -1;
  }

  .answers-column .column-cards {
    display: grid;
    grid-template-columns: repeat(3, minmax(0, 1fr));
  }

  .set-card {
    width: 100%;
  }

  .candidate-button {
    width: 100%;
  }

  .embedded-given {
    width: 100%;
  }

  .feature-guide {
    grid-template-columns: 1fr;
  }

  .example-cards .set-card {
    width: min(27vw, 92px);
  }

  .modal-card {
    padding: 20px;
  }
}

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