:root {
  color-scheme: light;
  --bg: #f4f6f4;
  --surface: #ffffff;
  --text: #18221e;
  --muted: #61716a;
  --line: #d9e2dc;
  --primary: #17664d;
  --primary-dark: #104a38;
  --accent: #8a5a16;
  --correct: #147d4f;
  --correct-bg: #e9f8f0;
  --wrong: #b42318;
  --wrong-bg: #fff0ee;
  --focus: #f2b84b;
}

* {
  box-sizing: border-box;
}

body {
  margin: 0;
  min-height: 100vh;
  background: var(--bg);
  color: var(--text);
  font-family: Arial, Helvetica, sans-serif;
  -webkit-text-size-adjust: 100%;
}

button,
input {
  font: inherit;
}

.app {
  width: min(1040px, calc(100% - 32px));
  margin: 0 auto;
  padding: 30px 0;
}

.topbar {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 16px;
  margin-bottom: 18px;
}

.eyebrow {
  margin: 0 0 6px;
  color: var(--primary);
  font-size: 0.82rem;
  font-weight: 700;
  text-transform: uppercase;
}

h1,
h2,
h3,
p {
  margin-top: 0;
}

h1 {
  margin-bottom: 0;
  font-size: clamp(2rem, 4vw, 3rem);
  line-height: 1.05;
}

.scorebox,
.controls,
.progress-wrap,
.quiz-card,
.results,
.usage-panel {
  border: 1px solid var(--line);
  border-radius: 8px;
  background: var(--surface);
}

.scorebox {
  min-width: 132px;
  padding: 14px 16px;
  text-align: center;
}

.scorebox span {
  display: block;
  color: var(--primary);
  font-size: 2.1rem;
  font-weight: 800;
  line-height: 1;
}

.scorebox small {
  color: var(--muted);
  white-space: nowrap;
}

.controls {
  display: grid;
  grid-template-columns: 1fr auto;
  gap: 16px;
  align-items: end;
  padding: 16px;
  margin-bottom: 16px;
}

.module-grid {
  display: flex;
  flex-wrap: wrap;
  gap: 10px;
}

.module-option {
  display: grid;
  grid-template-columns: auto 1fr;
  gap: 8px;
  align-items: center;
  width: max-content;
  min-height: 36px;
  padding: 7px 10px;
  border: 1px solid var(--line);
  border-radius: 8px;
  background: #fbfcfb;
  cursor: pointer;
  font-size: 0.86rem;
}

.module-option input,
.answer input {
  width: 18px;
  height: 18px;
  accent-color: var(--primary);
}

.control-actions,
.actions {
  display: flex;
  flex-wrap: wrap;
  gap: 10px;
}

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

.order-toggle {
  display: inline-grid;
  grid-template-columns: auto 1fr;
  gap: 8px;
  align-items: center;
  min-height: 44px;
  padding: 9px 12px;
  border: 1px solid var(--line);
  border-radius: 8px;
  background: #ffffff;
  color: var(--primary);
  font-weight: 700;
  cursor: pointer;
}

.order-toggle input {
  width: 18px;
  height: 18px;
  accent-color: var(--primary);
}

.order-toggle:has(input:checked) {
  border-color: var(--primary);
  background: var(--correct-bg);
}

.progress-wrap {
  padding: 16px;
  margin-bottom: 16px;
}

.progress-meta {
  display: flex;
  justify-content: space-between;
  gap: 12px;
  margin-bottom: 10px;
  color: var(--muted);
  font-size: 0.95rem;
}

.progress-track {
  height: 12px;
  overflow: hidden;
  border-radius: 999px;
  background: #e5ece7;
}

.progress-bar {
  height: 100%;
  border-radius: inherit;
  background: var(--primary);
}

.quiz-card,
.results,
.usage-panel {
  padding: 24px;
}

.question-meta {
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
  margin-bottom: 14px;
}

.question-meta span {
  border: 1px solid var(--line);
  border-radius: 999px;
  padding: 6px 10px;
  color: var(--muted);
  font-size: 0.9rem;
}

.difficulty-badge.difficult {
  border-color: transparent;
  background: var(--wrong-bg);
  color: var(--wrong);
  font-weight: 700;
}

.difficulty-badge.easy {
  border-color: transparent;
  background: var(--correct-bg);
  color: var(--correct);
  font-weight: 700;
}

#questionText {
  margin-bottom: 16px;
  font-size: 1.12rem;
  line-height: 1.42;
}

.answers {
  display: grid;
  gap: 10px;
}

.answer {
  display: grid;
  grid-template-columns: auto 1fr;
  gap: 12px;
  align-items: start;
  min-height: 54px;
  padding: 14px;
  border: 1px solid var(--line);
  border-radius: 8px;
  background: #fbfcfb;
  cursor: pointer;
}

.answer:hover,
.module-option:hover {
  border-color: var(--primary);
}

.answer.correct {
  border-color: var(--correct);
  background: var(--correct-bg);
}

.answer.wrong {
  border-color: var(--wrong);
  background: var(--wrong-bg);
}

.answer.disabled {
  cursor: default;
}

.option-id {
  font-weight: 700;
  text-transform: uppercase;
}

.actions {
  margin-top: 18px;
}

button {
  min-height: 44px;
  border: 1px solid var(--line);
  border-radius: 8px;
  padding: 10px 16px;
  background: #ffffff;
  color: var(--text);
  cursor: pointer;
}

button:hover {
  border-color: var(--primary);
}

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

button.primary {
  border-color: var(--primary);
  background: var(--primary);
  color: #ffffff;
  font-weight: 700;
}

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

button.secondary {
  color: var(--primary);
  font-weight: 700;
}

button.active-mode {
  border-color: var(--primary);
  background: var(--primary);
  color: #ffffff;
  font-weight: 700;
}

button:disabled {
  cursor: not-allowed;
  opacity: 0.6;
}

.feedback {
  margin-top: 18px;
  padding: 16px;
  border-radius: 8px;
  border: 1px solid var(--line);
  line-height: 1.55;
}

.feedback.success {
  border-color: var(--correct);
  background: var(--correct-bg);
}

.feedback.error {
  border-color: var(--wrong);
  background: var(--wrong-bg);
}

.feedback h3 {
  margin: 12px 0 6px;
  font-size: 1rem;
}

.feedback h3:first-child {
  margin-top: 0;
}

.feedback-list {
  display: grid;
  gap: 7px;
  margin: 0;
  padding-left: 20px;
}

.source-note {
  margin: 12px 0 0;
  color: var(--muted);
  font-size: 0.92rem;
}

.results {
  margin-top: 16px;
}

.usage-panel {
  display: grid;
  grid-template-columns: minmax(180px, 0.8fr) 2fr;
  gap: 18px;
  align-items: start;
  margin-top: 16px;
}

.usage-panel h2 {
  margin-bottom: 0;
  font-size: 1.25rem;
}

.usage-grid {
  display: grid;
  grid-template-columns: repeat(4, minmax(0, 1fr));
  gap: 10px;
}

.usage-stat {
  min-height: 76px;
  padding: 12px;
  border: 1px solid var(--line);
  border-radius: 8px;
  background: #f9fbfa;
}

.usage-stat span {
  display: block;
  color: var(--primary);
  font-size: 1.55rem;
  font-weight: 800;
  line-height: 1;
}

.usage-stat small {
  display: block;
  margin-top: 7px;
  color: var(--muted);
  line-height: 1.25;
}

.usage-note {
  grid-column: 1 / -1;
  margin: 0;
  color: var(--muted);
  font-size: 0.92rem;
}

@media (max-width: 760px) {
  .app {
    width: 100%;
    padding: 12px 10px 20px;
  }

  .topbar,
  .progress-meta {
    display: grid;
    grid-template-columns: 1fr;
  }

  h1 {
    font-size: 1.7rem;
  }

  .controls,
  .usage-panel {
    grid-template-columns: 1fr;
  }

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

  .quiz-card,
  .results,
  .usage-panel,
  .progress-wrap,
  .controls {
    padding: 14px;
  }

  #questionText {
    font-size: 1.04rem;
  }

  .control-actions,
  .actions {
    display: grid;
  }

  button {
    width: 100%;
    min-height: 48px;
  }
}