:root {
  color-scheme: dark;
  --green-950: #143f31;
  --green-850: #1d4c3e;
  --green-780: #275b4b;
  --cream: #e0d4bc;
  --cream-hover: #decaa2;
  --muted: #9cb4ab;
  --placeholder: #6f9085;
  --white: #ffffff;
  --danger: #ffb4ab;
  --danger-bg: #54251f;
  --success: #cce8d8;
  --success-bg: #184b35;
  --partial: #ffe0a3;
  --partial-bg: #5a4319;
  font-family: ui-sans-serif, system-ui, -apple-system, BlinkMacSystemFont, "Segoe UI", sans-serif;
}

* { box-sizing: border-box; }
html { min-width: 320px; background: var(--green-950); }
body { margin: 0; min-height: 100vh; color: var(--white); background: var(--green-950); font-size: 16px; line-height: 1.5; }
button, input, textarea { font: inherit; }
button { cursor: pointer; }
button:disabled { cursor: not-allowed; opacity: .55; }
[hidden] { display: none !important; }

.page-shell { min-height: 100vh; padding: 1rem; }
.app-width { width: 100%; max-width: 48rem; margin: 0 auto; }
.app-header { margin-bottom: 1.5rem; }
.app-header h1 { margin: 0 0 .15rem; font-size: clamp(1.5rem, 4.5vw, 1.875rem); line-height: 1.2; letter-spacing: -.025em; }
.app-header p { margin: 0 0 .75rem; font-size: .875rem; }
.app-header a { color: var(--cream); text-underline-offset: 2px; }
.utility-row { display: flex; flex-wrap: wrap; gap: .375rem; }

.outline-button, .text-button, .primary-button { border: 0; border-radius: .5rem; font-weight: 600; transition: background-color .16s ease, color .16s ease, border-color .16s ease, transform .08s ease; }
.outline-button { padding: .28rem .75rem; border: 2px solid var(--cream); border-radius: .25rem; background: transparent; color: var(--cream); font-size: .8rem; }
.outline-button:hover { color: var(--green-950); background: var(--cream); }
.outline-button:active, .primary-button:active { transform: translateY(1px); }
.text-button { padding: .45rem .2rem; color: var(--cream); background: transparent; text-decoration: underline; text-underline-offset: 3px; }
.text-button:hover { color: var(--white); }
.primary-button { width: 100%; margin-top: 1rem; padding: .75rem 1rem; color: var(--green-950); background: var(--cream); }
.primary-button:hover { background: var(--cream-hover); }
.compact-primary { width: auto; margin: 0; }

.panel { padding: 1rem; border-radius: .5rem; background: var(--green-850); box-shadow: 0 12px 30px rgba(4, 25, 18, .24); }
.field { margin-bottom: 1rem; }
.field label, .choice-card legend { display: block; margin-bottom: .3rem; color: var(--white); font-size: .875rem; }
.field input, .field textarea, .review-input, .answer-textarea {
  width: 100%; padding: .62rem .7rem; border: 1px solid #e5e7eb; border-radius: .25rem;
  outline: none; color: var(--white); background: var(--green-950);
}
.field textarea, .answer-textarea { resize: vertical; min-height: 5.2rem; }
.field input::placeholder, .field textarea::placeholder, .answer-textarea::placeholder { color: var(--placeholder); opacity: 1; }
.field input:focus, .field textarea:focus, .review-input:focus, .answer-textarea:focus { border-color: var(--cream); box-shadow: 0 0 0 3px rgba(224, 212, 188, .16); }
.field-hint { margin: .25rem 0 0; color: var(--muted); font-size: .78rem; }

.choice-card { margin: 0 0 1rem; padding: .75rem; border: 0; border-radius: .5rem; background: var(--green-950); }
.choice-card legend { float: left; width: 100%; margin-bottom: .55rem; font-weight: 600; }
.choice-card legend + * { clear: left; }
.compact-choice { display: flex; align-items: center; flex-wrap: wrap; gap: .45rem .8rem; }
.compact-choice legend { float: none; width: auto; margin: 0 auto 0 0; }
.radio-option, .large-radio { display: flex; align-items: center; gap: .42rem; cursor: pointer; }
.radio-option input, .large-radio input { width: 1rem; height: 1rem; margin: 0; accent-color: var(--cream); }
.question-choice { display: grid; grid-template-columns: 1fr 1fr; gap: .55rem; }
.question-choice legend { grid-column: 1 / -1; }
.large-radio { align-items: flex-start; padding: .7rem; border: 1px solid var(--green-780); border-radius: .4rem; }
.large-radio:hover { border-color: var(--cream); }
.large-radio span { display: grid; gap: .08rem; }
.large-radio small { color: var(--muted); font-size: .78rem; }

.status-message { margin: .75rem 0; padding: .7rem .8rem; border: 1px solid var(--danger); border-radius: .4rem; color: var(--danger); background: rgba(84, 37, 31, .45); }
.stage-panel { animation: rise .22s ease both; }
@keyframes rise { from { opacity: 0; transform: translateY(7px); } to { opacity: 1; transform: translateY(0); } }
.stage-heading { display: flex; align-items: flex-start; justify-content: space-between; gap: 1rem; margin-bottom: .75rem; }
.stage-heading h2 { margin: .05rem 0 0; font-size: 1.45rem; line-height: 1.25; }
.step-label { color: var(--cream); font-size: .72rem; font-weight: 700; letter-spacing: .1em; text-transform: uppercase; }
.stage-intro { margin: .9rem 0 1.1rem; color: #e7efeb; }
.article-banner { padding: .75rem; border-left: 4px solid var(--cream); border-radius: 0 .4rem .4rem 0; background: var(--green-950); }
.article-banner strong { display: block; }
.article-banner a { display: inline-block; margin-top: .2rem; color: var(--cream); font-size: .8rem; overflow-wrap: anywhere; }

.question-list { display: grid; gap: .85rem; }
.question-card { padding: .9rem; border-radius: .5rem; background: var(--green-950); }
.question-card h3 { margin: 0 0 .65rem; font-size: 1rem; line-height: 1.4; }
.question-number { color: var(--cream); }
.review-grid { display: grid; gap: .65rem; }
.review-grid label { color: var(--muted); font-size: .8rem; }
.review-grid label span { display: block; margin-bottom: .2rem; }
.review-options { display: grid; gap: .45rem; }
.review-option { display: grid; grid-template-columns: auto 1fr; align-items: center; gap: .55rem; }
.review-option input[type="radio"] { width: 1rem; height: 1rem; accent-color: var(--cream); }
.review-input { padding: .5rem .6rem; }
.answer-options { display: grid; gap: .48rem; }
.answer-option { display: flex; align-items: flex-start; gap: .58rem; padding: .65rem; border: 1px solid var(--green-780); border-radius: .4rem; cursor: pointer; }
.answer-option:hover, .answer-option:has(input:checked) { border-color: var(--cream); background: rgba(224, 212, 188, .08); }
.answer-option input { flex: 0 0 auto; width: 1rem; height: 1rem; margin-top: .18rem; accent-color: var(--cream); }

.score-card { display: flex; align-items: center; justify-content: space-between; gap: 1rem; margin: .9rem 0 1rem; padding: 1rem; border-radius: .5rem; color: var(--green-950); background: var(--cream); }
.score-card strong { font-size: 1.55rem; line-height: 1; }
.score-card span { text-align: right; }
.result-list { display: grid; gap: .8rem; }
.result-card { padding: .9rem; border: 1px solid var(--green-780); border-radius: .5rem; background: var(--green-950); }
.result-card.is-correct { border-color: #73c99a; }
.result-card.is-wrong { border-color: #dd857a; }
.result-head { display: flex; justify-content: space-between; gap: .8rem; margin-bottom: .55rem; }
.result-head h3 { margin: 0; font-size: 1rem; }
.result-badge { flex: 0 0 auto; padding: .16rem .5rem; border-radius: 999px; font-size: .75rem; font-weight: 700; }
.result-badge.correct { color: var(--success); background: var(--success-bg); }
.result-badge.wrong { color: var(--danger); background: var(--danger-bg); }
.result-row { margin-top: .48rem; }
.result-row b { color: var(--cream); }
.result-row p { margin: .15rem 0 0; white-space: pre-wrap; }
.result-actions { display: flex; justify-content: flex-end; flex-wrap: wrap; gap: .55rem; margin-top: 1rem; }

.loading-overlay { position: fixed; inset: 0; z-index: 20; display: grid; place-items: center; padding: 1rem; background: rgba(7, 29, 22, .82); backdrop-filter: blur(3px); }
.loading-card { display: grid; justify-items: center; gap: .65rem; width: min(100%, 26rem); padding: 1.4rem; border: 1px solid var(--green-780); border-radius: .65rem; text-align: center; background: var(--green-850); box-shadow: 0 18px 45px rgba(0,0,0,.3); }
.loading-card span:last-child { color: var(--muted); font-size: .88rem; }
.spinner { width: 2rem; height: 2rem; border: 3px solid var(--green-780); border-top-color: var(--cream); border-radius: 50%; animation: spin .8s linear infinite; }
@keyframes spin { to { transform: rotate(360deg); } }
.sr-only { position: absolute; width: 1px; height: 1px; padding: 0; margin: -1px; overflow: hidden; clip: rect(0,0,0,0); white-space: nowrap; border: 0; }

@media (min-width: 768px) {
  .page-shell { padding: 2rem; }
  .panel { padding: 1.5rem; }
}
@media (max-width: 620px) {
  .question-choice { grid-template-columns: 1fr; }
  .question-choice legend { grid-column: auto; }
  .stage-heading { display: block; }
  .stage-heading .text-button { margin-top: .45rem; }
  .score-card { align-items: flex-start; }
  .score-card span { text-align: left; }
}
@media (prefers-reduced-motion: reduce) {
  *, *::before, *::after { scroll-behavior: auto !important; animation-duration: .01ms !important; animation-iteration-count: 1 !important; transition-duration: .01ms !important; }
}