/* Medical Terminology Decoder — restrained, calm, legible styles.
   PRD Section 18.13: one centered reading column, high-contrast text,
   compact progress/nav, bordered+labeled tiles, no gamification. */

:root {
  --color-bg: #ffffff;
  --color-text: #1a1d21;
  --color-muted: #52585f;
  --color-border: #d6dbe0;
  --color-surface: #f6f7f9;
  --color-primary: #0b5fae;
  --color-primary-contrast: #ffffff;
  --color-correct: #1a7f37;
  --color-correct-bg: #e9f6ee;
  --color-incorrect: #a4222c;
  --color-incorrect-bg: #fbeceb;
  --color-focus: #d0021b;
  --font-body: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, Helvetica, Arial, sans-serif;
  --max-width: 46rem;
  --radius: 0.4rem;
}

@media (prefers-color-scheme: dark) {
  :root {
    --color-bg: #14171a;
    --color-text: #edeff2;
    --color-muted: #b0b6bd;
    --color-border: #3a3f45;
    --color-surface: #1d2124;
    --color-primary: #6cb2ff;
    --color-primary-contrast: #0b1622;
    --color-correct: #6fd08c;
    --color-correct-bg: #123420;
    --color-incorrect: #ff8a8f;
    --color-incorrect-bg: #3a1315;
    --color-focus: #ff6b6b;
  }
}

* {
  box-sizing: border-box;
}

html {
  color-scheme: light dark;
}

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

@media (prefers-reduced-motion: no-preference) {
  a, button, .chip, .tile {
    transition: background-color 120ms ease, border-color 120ms ease, color 120ms ease;
  }
}

.skip-link {
  position: absolute;
  left: -999px;
  top: 0;
  background: var(--color-primary);
  color: var(--color-primary-contrast);
  padding: 0.5rem 1rem;
  z-index: 10;
}
.skip-link:focus {
  left: 0.5rem;
  top: 0.5rem;
}

:focus-visible {
  outline: 3px solid var(--color-focus);
  outline-offset: 2px;
}

.app-header {
  border-bottom: 1px solid var(--color-border);
  background: var(--color-surface);
}
.app-header-inner {
  max-width: var(--max-width);
  margin: 0 auto;
  padding: 0.75rem 1rem;
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 1rem;
  justify-content: space-between;
}
.app-brand {
  font-weight: 700;
  text-decoration: none;
  color: var(--color-text);
  font-size: 1.05rem;
}
.app-nav {
  display: flex;
  gap: 0.75rem;
  flex-wrap: wrap;
}
.app-nav a {
  color: var(--color-primary);
  text-decoration: none;
  padding: 0.4rem 0.5rem;
  border-radius: var(--radius);
  min-height: 44px;
  display: inline-flex;
  align-items: center;
}
.app-nav a:hover {
  background: var(--color-border);
}

.app-main {
  max-width: var(--max-width);
  margin: 0 auto;
  padding: 1.25rem 1rem 3rem;
}

.app-footer {
  max-width: var(--max-width);
  margin: 0 auto;
  padding: 1rem 1rem 2.5rem;
  color: var(--color-muted);
  font-size: 0.9rem;
  border-top: 1px solid var(--color-border);
}

h1, h2, h3 {
  line-height: 1.25;
}
h1:focus, h2:focus {
  outline: none;
}

.subtitle {
  color: var(--color-muted);
  font-size: 1.05rem;
}

.safety-banner {
  background: var(--color-surface);
  border: 1px solid var(--color-border);
  border-left: 4px solid var(--color-primary);
  padding: 0.75rem 1rem;
  border-radius: var(--radius);
}

.stat-list {
  display: grid;
  grid-template-columns: auto 1fr;
  gap: 0.25rem 1rem;
  margin: 1rem 0;
}
.stat-list dt {
  font-weight: 600;
  color: var(--color-muted);
}
.stat-list dd {
  margin: 0;
}

.local-progress-note {
  color: var(--color-muted);
  font-size: 0.92rem;
}

/* Buttons */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 0.4rem;
  min-height: 44px;
  padding: 0.55rem 1rem;
  border-radius: var(--radius);
  border: 1px solid var(--color-border);
  background: var(--color-surface);
  color: var(--color-text);
  font-size: 1rem;
  cursor: pointer;
  text-decoration: none;
  margin: 0.15rem 0.3rem 0.15rem 0;
}
.btn:disabled {
  opacity: 0.55;
  cursor: not-allowed;
}
.btn-primary {
  background: var(--color-primary);
  border-color: var(--color-primary);
  color: var(--color-primary-contrast);
}
.btn-secondary {
  background: var(--color-bg);
}
.btn-ghost {
  background: transparent;
  border-color: transparent;
  text-decoration: underline;
}
.btn-danger {
  background: var(--color-incorrect-bg);
  border-color: var(--color-incorrect);
  color: var(--color-incorrect);
}
.btn-large {
  font-size: 1.1rem;
  padding: 0.75rem 1.25rem;
}
.btn-small {
  min-height: 36px;
  min-width: 36px;
  padding: 0.25rem 0.5rem;
}

/* Reference tables */
.reference-details, .learner-contract {
  border: 1px solid var(--color-border);
  border-radius: var(--radius);
  padding: 0.75rem 1rem;
  margin: 0.75rem 0;
  background: var(--color-surface);
}
.reference-details summary, .learner-contract summary {
  cursor: pointer;
  font-weight: 600;
}
.table-scroll {
  overflow-x: auto;
  margin: 0.5rem 0;
}
.ref-table {
  border-collapse: collapse;
  width: 100%;
  min-width: 24rem;
}
.ref-table th, .ref-table td {
  border: 1px solid var(--color-border);
  padding: 0.45rem 0.6rem;
  text-align: left;
  vertical-align: top;
}
.ref-table thead th {
  background: var(--color-surface);
}
.table-caption {
  font-weight: 600;
}
.table-note {
  color: var(--color-muted);
  font-size: 0.92rem;
}

.session-outline {
  padding-left: 1.25rem;
}
.session-status {
  color: var(--color-muted);
}

/* Word cards */
.card-set {
  display: grid;
  gap: 0.75rem;
  margin: 1rem 0;
}
.word-card {
  border: 1px solid var(--color-border);
  border-radius: var(--radius);
  padding: 0.9rem 1rem;
}
.card-forms {
  display: flex;
  align-items: center;
  gap: 0.6rem;
  margin: 0 0 0.5rem;
  font-size: 1.05rem;
}
.card-badge {
  font-size: 0.75rem;
  font-weight: 600;
  border: 1px solid var(--color-border);
  border-radius: 999px;
  padding: 0.15rem 0.55rem;
  color: var(--color-muted);
  text-transform: uppercase;
  letter-spacing: 0.02em;
}
.card-body {
  margin-top: 0.6rem;
  padding-top: 0.6rem;
  border-top: 1px dashed var(--color-border);
}
.card-coach {
  margin: 0.5rem 0;
  padding: 0.5rem 0.75rem;
  border-left: 3px solid var(--color-primary);
  background: var(--color-surface);
}
.example-label {
  font-weight: 600;
  margin-bottom: 0.25rem;
}
.example-list {
  margin: 0 0 0.5rem;
  padding-left: 1.25rem;
}
.example-more {
  margin-top: 0.5rem;
}

/* Questions */
.question, .block-exam-link, .exam-item {
  border: 1px solid var(--color-border);
  border-radius: var(--radius);
  padding: 0.9rem 1rem;
  margin: 0.85rem 0;
}
.question-prompt {
  font-weight: 600;
  margin-top: 0;
}
.question-feedback {
  min-height: 1.2rem;
}
.feedback {
  border-radius: var(--radius);
  padding: 0.5rem 0.7rem;
  margin: 0.5rem 0 0;
}
.feedback-correct {
  background: var(--color-correct-bg);
  color: var(--color-correct);
}
.feedback-incorrect {
  background: var(--color-incorrect-bg);
  color: var(--color-incorrect);
}
.feedback-hint {
  background: var(--color-surface);
  color: var(--color-muted);
}
.review-links {
  display: block;
  margin-top: 0.35rem;
  font-size: 0.9rem;
}
.review-chip {
  background: var(--color-surface);
  border: 1px solid var(--color-border);
  border-radius: 0.25rem;
  padding: 0.05rem 0.35rem;
  margin-right: 0.25rem;
}

.audio-controls {
  display: flex;
  align-items: center;
  flex-wrap: wrap;
  gap: 0.5rem;
  margin: 0.5rem 0;
}
.slower-toggle {
  display: inline-flex;
  align-items: center;
  gap: 0.3rem;
  color: var(--color-muted);
}
.transcript {
  width: 100%;
  color: var(--color-muted);
  font-style: italic;
}
.plays-remaining {
  color: var(--color-muted);
  font-size: 0.88rem;
}

.choice-options {
  display: flex;
  flex-wrap: wrap;
  gap: 0.4rem;
}
.btn-option {
  background: var(--color-bg);
}
.btn-option[aria-pressed="true"] {
  border-color: var(--color-primary);
  box-shadow: inset 0 0 0 1px var(--color-primary);
}
.option-correct, .option-answer {
  border-color: var(--color-correct);
  background: var(--color-correct-bg);
}
.option-incorrect {
  border-color: var(--color-incorrect);
  background: var(--color-incorrect-bg);
}

.self-check-answer {
  font-weight: 600;
}
.self-check-grade {
  margin-top: 0.5rem;
}

.match-table {
  border-collapse: collapse;
  width: 100%;
}
.match-table th, .match-table td {
  padding: 0.4rem 0.5rem;
  border-bottom: 1px solid var(--color-border);
  text-align: left;
}
.chip-group {
  display: flex;
  flex-wrap: wrap;
  gap: 0.3rem;
}
.chip {
  border: 1px solid var(--color-border);
  border-radius: 999px;
  background: var(--color-bg);
  color: var(--color-text);
  padding: 0.3rem 0.7rem;
  min-height: 36px;
  cursor: pointer;
}
.chip-selected {
  border-color: var(--color-primary);
  background: var(--color-primary);
  color: var(--color-primary-contrast);
}
.row-correct {
  background: var(--color-correct-bg);
}
.row-incorrect {
  background: var(--color-incorrect-bg);
}
.row-answer {
  margin: 0.25rem 0 0;
  font-size: 0.88rem;
  color: var(--color-muted);
}

.builder-tiles, .builder-answer {
  display: flex;
  flex-wrap: wrap;
  gap: 0.4rem;
  min-height: 44px;
  padding: 0.5rem;
  border: 1px dashed var(--color-border);
  border-radius: var(--radius);
  margin-bottom: 0.5rem;
}
.builder-label {
  font-weight: 600;
  margin: 0.5rem 0 0.25rem;
}
.builder-placeholder {
  color: var(--color-muted);
}
.tile {
  border: 2px solid var(--color-border);
  background: var(--color-surface);
  font-family: ui-monospace, SFMono-Regular, Menlo, Consolas, monospace;
}
.tile-placed {
  border-color: var(--color-primary);
}

.order-items {
  list-style: none;
  padding: 0;
  margin: 0 0 0.5rem;
  display: grid;
  gap: 0.4rem;
}
.order-item {
  display: flex;
  align-items: center;
  gap: 0.5rem;
  border: 1px solid var(--color-border);
  border-radius: var(--radius);
  padding: 0.4rem 0.6rem;
}
.order-item-label {
  flex: 1;
}

/* Lesson view */
.lesson-meta {
  color: var(--color-muted);
}
.lesson-overview {
  background: var(--color-surface);
  border: 1px solid var(--color-border);
  border-radius: var(--radius);
  padding: 0.75rem 1rem;
}
.lesson-finish {
  margin-top: 2rem;
  padding-top: 1rem;
  border-top: 1px solid var(--color-border);
}
.finish-status {
  color: var(--color-muted);
}
.finish-confirmation {
  color: var(--color-correct);
  font-weight: 600;
}
.lesson-nav {
  display: flex;
  flex-wrap: wrap;
  gap: 0.5rem;
  margin-top: 1rem;
}

/* Progress */
.progress-session-list {
  padding-left: 1.25rem;
}

/* Bonus */
.bonus-locked {
  background: var(--color-surface);
  border: 1px solid var(--color-border);
  border-radius: var(--radius);
  padding: 0.75rem 1rem;
}
.bonus-search {
  width: 100%;
  padding: 0.6rem 0.75rem;
  border: 1px solid var(--color-border);
  border-radius: var(--radius);
  margin: 0.5rem 0 1rem;
  font-size: 1rem;
  background: var(--color-bg);
  color: var(--color-text);
}
.bonus-group {
  border: 1px solid var(--color-border);
  border-radius: var(--radius);
  padding: 0.6rem 0.9rem;
  margin: 0.6rem 0;
}
.bonus-group summary {
  font-weight: 700;
  cursor: pointer;
}
.term-audio {
  margin-left: 0.4rem;
  padding: 0.1rem 0.4rem;
  min-height: 28px;
  min-width: 28px;
}
.scene-line {
  margin: 0.4rem 0;
}
.bonus-question summary {
  cursor: pointer;
}

/* Final exam */
.exam-progress {
  font-weight: 600;
}
.exam-item-number {
  margin-top: 0;
  color: var(--color-muted);
  font-size: 0.9rem;
  text-transform: uppercase;
  letter-spacing: 0.04em;
}
.exam-item-correct {
  border-color: var(--color-correct);
}
.exam-item-incorrect {
  border-color: var(--color-incorrect);
}
.exam-item-outcome {
  margin-top: 0.5rem;
  font-weight: 600;
}
.exam-band {
  font-weight: 600;
  font-size: 1.1rem;
}

.sr-only {
  position: absolute;
  width: 1px;
  height: 1px;
  overflow: hidden;
  clip: rect(0, 0, 0, 0);
}

code {
  background: var(--color-surface);
  border-radius: 0.2rem;
  padding: 0.05rem 0.3rem;
  font-family: ui-monospace, SFMono-Regular, Menlo, Consolas, monospace;
}

blockquote {
  margin: 0.5rem 0;
}

@media (max-width: 30rem) {
  .app-header-inner {
    flex-direction: column;
    align-items: flex-start;
  }
}