:root {
    --bg: #faf8f4;
    --bg-warm: #f5f0e8;
    --bg-card: #ffffff;
    --ink: #1a1a1a;
    --ink-light: #4a4540;
    --ink-muted: #8a8078;
    --accent: #b44a1e;
    --accent-light: #e8d5c4;
    --teal: #1a5c5a;
    --teal-light: #e0f0ef;
    --correct-bg: #e8f5e9;
    --correct-text: #2e7d32;
    --correct-border: #81c784;
    --wrong-bg: #fce4ec;
    --wrong-text: #c62828;
    --wrong-border: #ef9a9a;
    --stroke: #e0dbd3;
    --source-bg: #f0ece4;
}

* { margin: 0; padding: 0; box-sizing: border-box; }

body {
    font-family: 'Crimson Pro', Georgia, serif;
    background: var(--bg);
    color: var(--ink);
    line-height: 1.7;
    font-size: 18px;
}

/* -- top bar -- */
.topbar {
    position: sticky;
    top: 0;
    z-index: 100;
    background: rgba(250, 248, 244, 0.92);
    backdrop-filter: blur(12px);
    border-bottom: 1px solid var(--stroke);
    padding: 0.75rem 2rem;
    display: flex;
    justify-content: space-between;
    align-items: center;
}

.topbar-left {
    font-family: 'Source Sans 3', sans-serif;
    font-size: 0.85rem;
    font-weight: 600;
    color: var(--ink-muted);
    text-transform: uppercase;
    letter-spacing: 0.08em;
}

.topbar-left a {
    color: var(--accent);
    text-decoration: none;
}

.score-pill {
    font-family: 'JetBrains Mono', monospace;
    font-size: 0.8rem;
    background: var(--teal);
    color: #fff;
    padding: 0.35rem 1rem;
    border-radius: 20px;
}

/* -- hero -- */
.hero {
    max-width: 780px;
    margin: 0 auto;
    padding: 4rem 2rem 2rem;
    border-bottom: 2px solid var(--accent);
    margin-bottom: 3rem;
}

.hero-eyebrow {
    font-family: 'Source Sans 3', sans-serif;
    font-size: 0.8rem;
    font-weight: 700;
    text-transform: uppercase;
    letter-spacing: 0.15em;
    color: var(--accent);
    margin-bottom: 0.5rem;
}

.hero h1 {
    font-family: 'Crimson Pro', serif;
    font-size: clamp(2.2rem, 5vw, 3.2rem);
    font-weight: 700;
    line-height: 1.15;
    margin-bottom: 0.75rem;
    color: var(--ink);
}

.hero-sub {
    font-size: 1.15rem;
    color: var(--ink-light);
    font-style: italic;
    max-width: 560px;
}

/* -- chapter content area -- */
.chapter {
    max-width: 780px;
    margin: 0 auto;
    padding: 0 2rem 4rem;
}

/* -- section dividers -- */
.section-head {
    margin: 3rem 0 1.5rem;
    padding-bottom: 0.5rem;
    border-bottom: 1px solid var(--stroke);
}

.section-head h2 {
    font-family: 'Source Sans 3', sans-serif;
    font-size: 1.1rem;
    font-weight: 700;
    text-transform: uppercase;
    letter-spacing: 0.1em;
    color: var(--teal);
}

.section-head .section-count {
    font-family: 'JetBrains Mono', monospace;
    font-size: 0.75rem;
    color: var(--ink-muted);
}

/* -- question block -- */
.q-block {
    background: var(--bg-card);
    border: 1px solid var(--stroke);
    border-radius: 12px;
    margin-bottom: 1.75rem;
    overflow: hidden;
    box-shadow: 0 2px 8px rgba(0,0,0,0.04);
    transition: box-shadow 0.2s;
}

.q-block:hover {
    box-shadow: 0 4px 16px rgba(0,0,0,0.08);
}

/* source attribution bar */
.q-source {
    font-family: 'Source Sans 3', sans-serif;
    font-size: 0.78rem;
    font-weight: 600;
    color: var(--ink-muted);
    background: var(--source-bg);
    padding: 0.5rem 1.25rem;
    display: flex;
    justify-content: space-between;
    align-items: center;
    letter-spacing: 0.03em;
}

.q-source .book-tag {
    background: var(--accent-light);
    color: var(--accent);
    padding: 0.15rem 0.6rem;
    border-radius: 4px;
    font-size: 0.72rem;
    font-weight: 700;
    text-transform: uppercase;
}

.q-body {
    padding: 1.5rem 1.25rem;
}

/* figure inside question */
.q-figure {
    margin: 0 0 1.25rem;
    text-align: center;
}

.q-figure img {
    max-width: 100%;
    max-height: 340px;
    border-radius: 8px;
    border: 1px solid var(--stroke);
    background: #fff;
}

.q-figure figcaption {
    font-family: 'Source Sans 3', sans-serif;
    font-size: 0.78rem;
    color: var(--ink-muted);
    margin-top: 0.4rem;
    font-style: italic;
}

/* question number + text */
.q-num {
    font-family: 'JetBrains Mono', monospace;
    font-size: 0.8rem;
    font-weight: 500;
    color: var(--accent);
    margin-bottom: 0.4rem;
}

.q-stem {
    font-size: 1.05rem;
    line-height: 1.7;
    margin-bottom: 1.25rem;
    color: var(--ink);
}

/* options as styled list */
.q-options {
    list-style: none;
    margin-bottom: 1rem;
}

.q-options li {
    padding: 0.65rem 1rem;
    margin-bottom: 0.4rem;
    border: 1.5px solid var(--stroke);
    border-radius: 8px;
    cursor: pointer;
    transition: all 0.15s;
    font-size: 1rem;
    display: flex;
    align-items: baseline;
    gap: 0.6rem;
}

.q-options li:hover {
    background: var(--bg-warm);
    border-color: var(--ink-muted);
}

.q-options li .opt-letter {
    font-family: 'JetBrains Mono', monospace;
    font-size: 0.82rem;
    font-weight: 600;
    color: var(--ink-muted);
    min-width: 1.4rem;
}

.q-options li.selected {
    border-color: var(--teal);
    background: var(--teal-light);
}

.q-options li.correct {
    border-color: var(--correct-border);
    background: var(--correct-bg);
    color: var(--correct-text);
}

.q-options li.wrong {
    border-color: var(--wrong-border);
    background: var(--wrong-bg);
    color: var(--wrong-text);
}

.q-options li.disabled {
    pointer-events: none;
    opacity: 0.6;
}

/* reveal button */
.q-reveal-btn {
    font-family: 'Source Sans 3', sans-serif;
    font-size: 0.85rem;
    font-weight: 600;
    color: var(--teal);
    background: none;
    border: 1.5px solid var(--teal);
    border-radius: 6px;
    padding: 0.4rem 1rem;
    cursor: pointer;
    transition: all 0.15s;
}

.q-reveal-btn:hover {
    background: var(--teal);
    color: #fff;
}

/* answer/explanation panel */
.q-answer {
    display: none;
    margin-top: 1rem;
    padding: 1rem 1.25rem;
    background: var(--bg-warm);
    border-radius: 8px;
    border-left: 3px solid var(--teal);
}

.q-answer.visible {
    display: block;
}

.q-answer .answer-label {
    font-family: 'Source Sans 3', sans-serif;
    font-size: 0.78rem;
    font-weight: 700;
    text-transform: uppercase;
    letter-spacing: 0.08em;
    color: var(--teal);
    margin-bottom: 0.3rem;
}

.q-answer p {
    font-size: 0.95rem;
    line-height: 1.7;
    color: var(--ink-light);
}

/* -- score summary at bottom -- */
.score-summary {
    max-width: 780px;
    margin: 0 auto 4rem;
    padding: 2rem;
    background: var(--teal);
    color: #fff;
    border-radius: 12px;
    text-align: center;
    font-family: 'Source Sans 3', sans-serif;
    display: none;
}

.score-summary h3 {
    font-size: 1.3rem;
    margin-bottom: 0.5rem;
}

.score-summary .big-score {
    font-family: 'JetBrains Mono', monospace;
    font-size: 3rem;
    font-weight: 700;
}

.score-summary button {
    margin-top: 1rem;
    padding: 0.6rem 2rem;
    border: 2px solid #fff;
    background: none;
    color: #fff;
    border-radius: 8px;
    font-size: 1rem;
    cursor: pointer;
    font-family: 'Source Sans 3', sans-serif;
    font-weight: 600;
}

.score-summary button:hover {
    background: rgba(255,255,255,0.15);
}

/* -- responsive -- */
@media (max-width: 600px) {
    .hero { padding: 2.5rem 1rem 1.5rem; }
    .chapter { padding: 0 1rem 3rem; }
    .q-body { padding: 1rem; }
    .q-figure img { max-height: 220px; }
}