:root {
  color-scheme: light;
}

* {
  box-sizing: border-box;
}

body {
  margin: 0;
  background: var(--exercise-stage-background);
  color: var(--exercise-ink);
  font-family: var(--exercise-body-font);
}

button,
select,
input {
  font: inherit;
}

.page {
  width: min(960px, calc(100% - 40px));
  margin: 0 auto;
  padding: 44px 0 64px;
}

.page-header {
  display: grid;
  grid-template-columns: 1fr auto;
  gap: 24px;
  align-items: end;
  margin-bottom: 24px;
}

.eyebrow,
.question-kicker {
  color: var(--exercise-primary);
  font-size: 14px;
  font-weight: 700;
  letter-spacing: .08em;
  text-transform: uppercase;
}

h1 {
  margin: 8px 0 0;
  font-family: var(--exercise-title-font);
  font-size: clamp(32px, 5vw, 50px);
  line-height: 1.15;
}

.progress {
  color: var(--exercise-muted);
  font-weight: 600;
  white-space: nowrap;
}

.question-card,
.summary-card {
  min-height: 520px;
  padding: 42px;
  border: 1px solid var(--exercise-line);
  border-top: 6px solid var(--exercise-primary);
  border-radius: var(--exercise-radius);
  background: var(--exercise-surface);
  box-shadow: 0 18px 55px var(--exercise-card-shadow);
}

.question-card {
  display: flex;
  flex-direction: column;
}

.question-card[hidden],
.summary-card[hidden] {
  display: none;
}

h2 {
  max-width: none;
  margin: 14px 0 30px;
  font-size: 30px;
  line-height: 1.35;
}

.choices {
  display: grid;
  gap: 12px;
}

.choice {
  display: flex;
  gap: 14px;
  align-items: flex-start;
  padding: 16px 18px;
  border: 1px solid var(--exercise-line);
  border-radius: var(--exercise-radius);
  cursor: pointer;
}

.choice:has(input:checked) {
  border-color: var(--exercise-primary);
  background: var(--exercise-soft);
  box-shadow: inset 4px 0 var(--exercise-primary);
}

.choice input {
  width: 20px;
  height: 20px;
  margin: 2px 0 0;
  accent-color: var(--exercise-primary);
}

.choice-shortcut {
  margin-left: auto;
  color: var(--exercise-muted);
  font-weight: 600;
  white-space: nowrap;
}

.matching-grid {
  display: grid;
  gap: 14px;
}

.matching-row {
  display: grid;
  grid-template-columns: minmax(130px, .7fr) minmax(220px, 1.3fr);
  gap: 18px;
  align-items: center;
}

select {
  width: 100%;
  padding: 12px 14px;
  border: 1px solid var(--exercise-line);
  border-radius: var(--exercise-radius);
  background: var(--exercise-surface);
  color: var(--exercise-ink);
}

.ordering-list {
  display: grid;
  gap: 10px;
  padding: 0;
  list-style: none;
  counter-reset: order;
}

.ordering-item {
  display: grid;
  grid-template-columns: 1fr auto;
  gap: 16px;
  align-items: center;
  padding: 13px 15px;
  border: 1px solid var(--exercise-line);
  border-radius: var(--exercise-radius);
  counter-increment: order;
}

.ordering-item > span:first-child::before {
  content: counter(order) ". ";
  color: var(--exercise-primary);
  font-weight: 700;
}

.ordering-controls {
  display: flex;
  gap: 6px;
}

.ordering-move {
  width: 38px;
  height: 34px;
  border: 1px solid var(--exercise-line);
  border-radius: var(--exercise-radius);
  background: var(--exercise-surface);
  cursor: pointer;
}

.ordering-move[aria-disabled="true"] {
  cursor: not-allowed;
  opacity: .42;
}

.ordering-status {
  position: absolute;
  width: 1px;
  height: 1px;
  padding: 0;
  margin: -1px;
  overflow: hidden;
  clip: rect(0, 0, 0, 0);
  white-space: nowrap;
  border: 0;
}

.question-action {
  margin-top: auto;
  padding-top: 28px;
}

.action-row {
  display: flex;
  justify-content: space-between;
  align-items: flex-end;
  gap: 24px;
}

.action-copy {
  min-width: 0;
}

.instruction {
  margin: 0;
  color: var(--exercise-muted);
}

.response-warning {
  margin: 8px 0 0;
  color: var(--exercise-bad);
  font-weight: 700;
}

button.primary {
  padding: 12px 22px;
  border: 0;
  border-radius: var(--exercise-radius);
  background: var(--exercise-primary);
  color: var(--exercise-on-primary);
  font-weight: 700;
  cursor: pointer;
}

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

button:disabled,
select:disabled,
input:disabled {
  cursor: not-allowed;
  opacity: .72;
}

.feedback {
  margin: 0 0 22px;
  padding: 18px 20px;
  border-left: 6px solid var(--exercise-primary);
  background: var(--exercise-soft);
  line-height: 1.65;
}

.feedback p {
  margin: 0 0 8px;
}

.feedback p:last-child {
  margin-bottom: 0;
}

.result-correct {
  color: var(--exercise-good);
  font-weight: 800;
}

.result-incorrect {
  color: var(--exercise-bad);
  font-weight: 800;
}

.navigation {
  display: flex;
  justify-content: space-between;
  align-items: center;
  gap: 12px;
  margin-top: 20px;
}

.navigation button {
  min-width: 142px;
  min-height: 56px;
  padding: 14px 28px;
  border: 1px solid var(--exercise-line);
  border-radius: var(--exercise-radius);
  background: var(--exercise-surface);
  color: var(--exercise-ink);
  font-size: 18px;
  font-weight: 700;
  cursor: pointer;
}

.navigation button:disabled {
  visibility: hidden;
}

.summary-grid {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 12px;
  margin: 28px 0;
}

.summary-grid div {
  padding: 18px;
  border-radius: var(--exercise-radius);
  background: var(--exercise-soft);
}

.summary-grid strong {
  display: block;
  margin-top: 8px;
  color: var(--exercise-primary);
  font-size: 30px;
}

@media (max-width: 680px) {
  .page {
    width: min(100% - 24px, 960px);
    padding-top: 24px;
  }

  .page-header {
    grid-template-columns: 1fr;
  }

  .question-card,
  .summary-card {
    min-height: 0;
    padding: 26px 20px;
  }

  h2 {
    font-size: 25px;
  }

  .matching-row {
    grid-template-columns: 1fr;
    gap: 6px;
  }

  .action-row {
    flex-direction: column;
    align-items: stretch;
  }

  .action-row .primary {
    align-self: flex-end;
  }

  .navigation button {
    min-width: 0;
    flex: 1;
  }

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