:root {
  color-scheme: light;
  --color-bg: oklch(1 0 0);
  --color-ink: oklch(0.23 0.025 130);
  --color-muted: oklch(0.47 0.022 130);
  --color-line: oklch(0.82 0.012 130);
  --color-line-strong: oklch(0.58 0.025 130);
  --color-primary: oklch(0.5 0.135 130);
  --color-primary-dark: oklch(0.39 0.105 130);
  --color-primary-pale: oklch(0.96 0.025 130);
  --color-error: oklch(0.46 0.16 25);
  --color-error-pale: oklch(0.965 0.02 25);
  --color-focus: oklch(0.39 0.105 130);

  --font-sans: -apple-system, BlinkMacSystemFont, "Segoe UI", system-ui, sans-serif;
  --text-small: 0.875rem;
  --text-body: 1rem;
  --text-question: 1.125rem;
  --text-heading: 1.75rem;
  --weight-normal: 400;
  --weight-semibold: 600;
  --weight-bold: 700;

  --space-2xs: 0.25rem;
  --space-xs: 0.5rem;
  --space-sm: 0.75rem;
  --space-md: 1rem;
  --space-lg: 1.5rem;
  --space-xl: 2rem;
  --space-2xl: 3rem;
  --space-3xl: 4.5rem;

  --ease-out: cubic-bezier(0.25, 1, 0.5, 1);
  --z-skip-link: 4;
}

*,
*::before,
*::after {
  box-sizing: border-box;
}

html {
  background: var(--color-bg);
  font-family: var(--font-sans);
  font-kerning: normal;
  text-size-adjust: 100%;
}

body {
  margin: 0;
  background: var(--color-bg);
  color: var(--color-ink);
  font-size: var(--text-body);
  line-height: 1.55;
}

button,
input {
  font: inherit;
}

button {
  color: inherit;
}

button,
label {
  -webkit-tap-highlight-color: transparent;
}

.skip-link {
  position: fixed;
  top: var(--space-sm);
  left: var(--space-sm);
  z-index: var(--z-skip-link);
  padding: var(--space-sm) var(--space-md);
  background: var(--color-ink);
  color: var(--color-bg);
  transform: translateY(-160%);
  transition: transform 160ms var(--ease-out);
}

.skip-link:focus {
  transform: translateY(0);
}

main {
  width: min(calc(100% - 2rem), 44rem);
  margin-inline: auto;
  padding-block: max(var(--space-2xl), env(safe-area-inset-top))
    max(var(--space-3xl), env(safe-area-inset-bottom));
}

.sheet-header {
  margin-bottom: var(--space-xl);
}

.level-row {
  display: flex;
  flex-wrap: wrap;
  min-height: 2.75rem;
  align-items: center;
  justify-content: space-between;
  gap: var(--space-md);
}

.level-row .level {
  margin: 0;
}

.level {
  margin: 0 0 var(--space-xs);
  color: var(--color-muted);
  font-size: var(--text-small);
  font-variant-numeric: tabular-nums;
}

h1,
h2,
p {
  text-wrap: pretty;
}

h1 {
  margin: 0;
  font-size: var(--text-heading);
  font-weight: var(--weight-bold);
  letter-spacing: -0.02em;
  line-height: 1.2;
  text-wrap: balance;
}

.sheet-rule {
  width: 100%;
  height: 1px;
  margin-top: var(--space-lg);
  border: 0;
  background: var(--color-ink);
}

.questions {
  display: flex;
  flex-direction: column;
  gap: var(--space-2xl);
  padding-block: var(--space-sm) var(--space-2xl);
}

.question {
  display: grid;
  grid-template-columns: 3.25rem minmax(0, 1fr);
  gap: var(--space-md);
  scroll-margin-top: var(--space-xl);
}

.question-number {
  padding-top: var(--space-2xs);
  font-size: var(--text-question);
  font-variant-numeric: tabular-nums;
  font-weight: var(--weight-semibold);
}

.question-content {
  min-width: 0;
}

.question-line {
  display: flex;
  align-items: flex-start;
  gap: var(--space-sm);
  min-height: 2.75rem;
  margin: 0;
  font-size: var(--text-question);
  line-height: 1.45;
}

.prompt {
  padding-top: var(--space-xs);
}

.help-button {
  display: inline-grid;
  flex: 0 0 2.75rem;
  width: 2.75rem;
  height: 2.75rem;
  place-items: center;
  border: 0;
  border-radius: 50%;
  background: transparent;
  cursor: pointer;
}

.help-button::before {
  display: grid;
  width: 1.75rem;
  height: 1.75rem;
  border: 1px solid var(--color-line-strong);
  border-radius: 50%;
  content: "?";
  place-items: center;
  transition:
    border-color 160ms var(--ease-out),
    color 160ms var(--ease-out),
    background-color 160ms var(--ease-out);
}

@media (hover: hover) {
  .help-button:hover::before {
    border-color: var(--color-primary-dark);
    color: var(--color-primary-dark);
    background: var(--color-primary-pale);
  }
}

.help-button[aria-expanded="true"]::before {
  border-color: var(--color-primary);
  background: var(--color-primary);
  color: var(--color-bg);
}

.help-button:focus-visible,
.text-answer:focus-visible,
.choice input:focus-visible,
.action:focus-visible,
.text-action:focus-visible,
.progress-link:focus-visible {
  outline: 3px solid var(--color-focus);
  outline-offset: 3px;
}

#main-content:focus,
#page-title:focus,
#sheet-result:focus {
  outline: 3px solid var(--color-focus);
  outline-offset: 4px;
}

.answer-fieldset {
  min-width: 0;
  margin: var(--space-sm) 0 0;
  padding: 0;
  border: 0;
}

.choices {
  display: flex;
  flex-wrap: wrap;
  gap: var(--space-xs) var(--space-xl);
}

.choices[data-long="true"] {
  align-items: stretch;
  flex-direction: column;
  gap: var(--space-2xs);
}

.choice {
  display: inline-flex;
  min-height: 2.75rem;
  align-items: center;
  gap: var(--space-sm);
  cursor: pointer;
}

.choice input {
  width: 1.25rem;
  height: 1.25rem;
  margin: 0;
  accent-color: var(--color-primary);
  cursor: pointer;
}

.choice span {
  border-radius: 2px;
  line-height: 1.4;
}

.text-answer {
  width: 100%;
  min-height: 2.75rem;
  margin-top: var(--space-xs);
  padding: var(--space-xs) 0;
  border: 0;
  border-bottom: 1px solid var(--color-line-strong);
  border-radius: 0;
  background: transparent;
  color: var(--color-ink);
  caret-color: var(--color-primary-dark);
}

.text-answer:focus {
  border-bottom-color: var(--color-primary-dark);
}

.concept {
  max-width: 58ch;
  margin-top: var(--space-md);
  padding-left: var(--space-xl);
  animation: concept-in 180ms var(--ease-out);
}

.concept[hidden] {
  display: none;
}

.concept h2 {
  position: relative;
  margin: 0 0 var(--space-xs);
  font-size: var(--text-body);
  font-weight: var(--weight-semibold);
}

.concept h2::before {
  position: absolute;
  right: calc(100% + var(--space-sm));
  content: "?";
  color: var(--color-primary-dark);
  font-weight: var(--weight-normal);
}

.concept p {
  margin: var(--space-2xs) 0 0;
}

.concept strong {
  font-weight: var(--weight-semibold);
}

.feedback {
  margin: var(--space-md) 0 0;
  font-weight: var(--weight-semibold);
}

.question[data-state="correct"] .feedback {
  color: var(--color-primary-dark);
}

.question[data-state="incorrect"] .feedback,
.question[data-state="missing"] .feedback {
  color: var(--color-error);
}

.question[data-state="incorrect"] .text-answer,
.question[data-state="missing"] .text-answer {
  border-bottom-color: var(--color-error);
  background: var(--color-error-pale);
}

.text-answer:disabled {
  color: var(--color-ink);
  opacity: 1;
}

.choice:has(input:disabled),
.choice input:disabled {
  cursor: default;
}

.sheet-footer {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  justify-content: space-between;
  gap: var(--space-md);
  padding-top: var(--space-lg);
  border-top: 1px solid var(--color-line);
}

.footer-secondary {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: var(--space-xs);
  margin-left: auto;
}

.action,
.text-action,
.progress-link {
  min-height: 2.75rem;
  border: 0;
  background: transparent;
  cursor: pointer;
  text-decoration-thickness: 1px;
  text-underline-offset: 0.24em;
}

.action {
  display: inline-flex;
  align-items: center;
  padding: var(--space-xs) 0;
  color: var(--color-primary-dark);
  font-weight: var(--weight-bold);
}

.text-action {
  padding: var(--space-xs);
  color: var(--color-muted);
  text-decoration: underline;
}

.progress-link {
  padding: var(--space-xs) 0;
  color: var(--color-muted);
  font-size: var(--text-small);
  text-decoration: underline;
}

@media (hover: hover) {
  .action:hover,
  .text-action:hover,
  .progress-link:hover {
    color: var(--color-ink);
  }
}

.action:active,
.text-action:active,
.progress-link:active,
.help-button:active {
  transform: translateY(1px);
}

.sheet-result {
  margin: 0;
  font-weight: var(--weight-semibold);
}

.sheet-result[hidden] {
  display: none;
}

.progress-sheet {
  padding-top: 0;
}

.score {
  margin: 0 0 var(--space-xs);
  font-size: var(--text-question);
  font-weight: var(--weight-bold);
  font-variant-numeric: tabular-nums;
}

.summary-copy {
  max-width: 55ch;
  margin: 0 0 var(--space-xl);
  color: var(--color-muted);
}

.progress-detail {
  margin: 0 0 var(--space-xs);
  color: var(--color-muted);
  font-variant-numeric: tabular-nums;
}

.notice {
  margin: 0 0 var(--space-lg);
  color: var(--color-primary-dark);
  font-weight: var(--weight-semibold);
}

.topic-progress {
  margin: var(--space-xl) 0;
  padding: 0;
  border-top: 1px solid var(--color-line);
  list-style: none;
}

.topic-progress li {
  display: flex;
  min-height: 2.75rem;
  align-items: center;
  justify-content: space-between;
  gap: var(--space-lg);
  padding-block: var(--space-xs);
  border-bottom: 1px solid var(--color-line);
}

.topic-progress li span:last-child {
  flex: 0 0 auto;
  color: var(--color-muted);
  font-variant-numeric: tabular-nums;
}

.summary-actions {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: var(--space-sm) var(--space-xl);
  padding-top: var(--space-lg);
  border-top: 1px solid var(--color-line);
}

.storage-note {
  margin: var(--space-lg) 0 0;
  color: var(--color-muted);
  font-size: var(--text-small);
  font-variant-numeric: tabular-nums;
}

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

noscript {
  display: block;
  padding: var(--space-lg) 0;
}

@keyframes concept-in {
  from {
    opacity: 0;
    transform: translateY(-0.25rem);
  }
  to {
    opacity: 1;
    transform: translateY(0);
  }
}

@media (min-width: 42rem) {
  main {
    padding-top: max(var(--space-3xl), env(safe-area-inset-top));
  }

  .questions {
    gap: var(--space-2xl);
  }
}

@media (max-width: 31rem) {
  :root {
    --text-heading: 1.5rem;
    --text-question: 1.0625rem;
  }

  main {
    width: min(calc(100% - 1.5rem), 44rem);
  }

  .question {
    grid-template-columns: 2.5rem minmax(0, 1fr);
    gap: var(--space-sm);
  }

  .question-line {
    gap: var(--space-xs);
  }

  .choices {
    align-items: flex-start;
    flex-direction: column;
    gap: var(--space-2xs);
  }

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

  .footer-secondary {
    margin-left: 0;
  }

  .topic-progress li {
    align-items: flex-start;
  }
}

@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;
  }
}

@media print {
  main {
    width: 100%;
    padding: 0;
  }

  .help-button,
  .progress-link,
  .sheet-footer,
  .feedback,
  .concept {
    display: none !important;
  }
}