:root {
    --bg: #f6f3ee;
    --card: rgba(255, 255, 255, 0.82);
    --card-solid: #ffffff;
    --text: #1e1c19;
    --muted: #7b746c;
    --border: rgba(30, 28, 25, 0.1);
    --accent: #111111;
    --accent-soft: rgba(17, 17, 17, 0.08);
    --success: #178a4c;
    --success-bg: #e7f6ee;
    --danger: #b42318;
    --danger-bg: #fdecea;
    --warning: #a15c00;
    --warning-bg: #fff4df;
    --radius-lg: 28px;
    --radius-md: 18px;
    --shadow: 0 24px 70px rgba(30, 28, 25, 0.08);
}

* {
    box-sizing: border-box;
}

html {
    min-height: 100%;
    background: var(--bg);
}

body {
    margin: 0;
    min-height: 100vh;
    background:
        radial-gradient(circle at top left, rgba(255,255,255,0.9), transparent 34rem),
        radial-gradient(circle at bottom right, rgba(17,17,17,0.06), transparent 28rem),
        var(--bg);
    color: var(--text);
    font-family: Inter, ui-sans-serif, system-ui, -apple-system, BlinkMacSystemFont, "Segoe UI", sans-serif;
    font-size: 16px;
    line-height: 1.5;
}

a {
    color: inherit;
}

button,
input,
textarea,
select {
    font: inherit;
}

.app-shell {
    width: min(980px, calc(100% - 32px));
    margin: 0 auto;
    padding: 32px 0;
}

.app-header {
    display: flex;
    align-items: center;
    justify-content: space-between;
    gap: 16px;
    margin-bottom: 28px;
}

.brand {
    display: flex;
    flex-direction: column;
    gap: 2px;
}

.brand-title {
    margin: 0;
    font-size: clamp(22px, 4vw, 34px);
    letter-spacing: -0.04em;
    line-height: 1;
}

.brand-subtitle {
    margin: 0;
    color: var(--muted);
    font-size: 14px;
}

.header-pill {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    min-height: 38px;
    padding: 8px 14px;
    border: 1px solid var(--border);
    border-radius: 999px;
    color: var(--muted);
    background: rgba(255,255,255,0.55);
    font-size: 14px;
    white-space: nowrap;
}

.card {
    background: var(--card);
    border: 1px solid var(--border);
    border-radius: var(--radius-lg);
    box-shadow: var(--shadow);
    backdrop-filter: blur(16px);
    -webkit-backdrop-filter: blur(16px);
}

.hero-card {
    padding: clamp(24px, 5vw, 48px);
}

.hero-eyebrow {
    margin: 0 0 14px;
    color: var(--muted);
    font-size: 14px;
    font-weight: 700;
    letter-spacing: 0.08em;
    text-transform: uppercase;
}

.hero-title {
    margin: 0;
    max-width: 760px;
    font-size: clamp(34px, 8vw, 72px);
    letter-spacing: -0.07em;
    line-height: 0.95;
}

.hero-text {
    margin: 22px 0 0;
    max-width: 640px;
    color: var(--muted);
    font-size: 17px;
}

.hero-actions {
    display: flex;
    flex-wrap: wrap;
    gap: 12px;
    margin-top: 30px;
}

.btn {
    appearance: none;
    border: 0;
    cursor: pointer;
    display: inline-flex;
    align-items: center;
    justify-content: center;
    min-height: 48px;
    padding: 13px 20px;
    border-radius: 999px;
    background: var(--accent);
    color: #ffffff;
    font-weight: 800;
    text-decoration: none;
    transition: transform 0.18s ease, opacity 0.18s ease, background 0.18s ease;
}

.btn:hover {
    transform: translateY(-1px);
}

.btn:active {
    transform: translateY(0);
    opacity: 0.86;
}

.btn.secondary {
    background: var(--accent-soft);
    color: var(--text);
}

.btn.danger {
    background: var(--danger);
    color: #ffffff;
}

.btn.full {
    width: 100%;
}

.stats-grid {
    display: grid;
    grid-template-columns: repeat(4, minmax(0, 1fr));
    gap: 12px;
    margin-top: 22px;
}

.stat-box {
    padding: 16px;
    border: 1px solid var(--border);
    border-radius: var(--radius-md);
    background: rgba(255,255,255,0.55);
}

.stat-value {
    display: block;
    font-size: 26px;
    font-weight: 900;
    letter-spacing: -0.04em;
}

.stat-label {
    display: block;
    color: var(--muted);
    font-size: 13px;
}

.question-card {
    overflow: hidden;
}

.question-top {
    display: flex;
    justify-content: space-between;
    gap: 18px;
    padding: 22px 24px;
    border-bottom: 1px solid var(--border);
}

.question-meta {
    display: flex;
    flex-direction: column;
    gap: 5px;
}

.question-kicker {
    color: var(--muted);
    font-size: 13px;
    font-weight: 700;
    letter-spacing: 0.06em;
    text-transform: uppercase;
}

.question-chapter {
    font-weight: 800;
}

.question-progress {
    flex: 0 0 auto;
    display: flex;
    align-items: center;
    justify-content: center;
    min-width: 92px;
    height: 42px;
    padding: 0 14px;
    border-radius: 999px;
    background: var(--accent-soft);
    font-weight: 900;
}

.question-body {
    padding: 24px;
}

.question-title {
    margin: 0 0 22px;
    font-size: clamp(20px, 4vw, 30px);
    line-height: 1.2;
    letter-spacing: -0.035em;
}

.options-list {
    display: grid;
    gap: 12px;
}

.option-row {
    display: grid;
    grid-template-columns: auto 1fr;
    gap: 12px;
    align-items: flex-start;
    padding: 16px;
    border: 1px solid var(--border);
    border-radius: var(--radius-md);
    background: rgba(255,255,255,0.62);
    cursor: pointer;
    transition: border 0.18s ease, background 0.18s ease, transform 0.18s ease;
}

.option-row:hover {
    border-color: rgba(17,17,17,0.25);
    transform: translateY(-1px);
}

.option-row input {
    width: 20px;
    height: 20px;
    margin: 2px 0 0;
    accent-color: var(--accent);
}

.option-letter {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    width: 30px;
    height: 30px;
    border-radius: 50%;
    background: var(--accent-soft);
    font-weight: 900;
    line-height: 1;
}

.option-content {
    display: flex;
    flex-direction: column;
    gap: 5px;
}

.option-text {
    color: var(--text);
}

.option-feedback {
    color: var(--muted);
    font-size: 13px;
    font-weight: 700;
}

.option-row.correct-selected,
.option-row.correct-ignored {
    border-color: rgba(23, 138, 76, 0.28);
    background: var(--success-bg);
}

.option-row.correct-selected .option-letter,
.option-row.correct-ignored .option-letter {
    background: var(--success);
    color: #ffffff;
}

.option-row.missed {
    border-color: rgba(161, 92, 0, 0.32);
    background: var(--warning-bg);
}

.option-row.missed .option-letter {
    background: var(--warning);
    color: #ffffff;
}

.option-row.wrong-selected {
    border-color: rgba(180, 35, 24, 0.28);
    background: var(--danger-bg);
}

.option-row.wrong-selected .option-letter {
    background: var(--danger);
    color: #ffffff;
}

.result-box {
    margin-top: 22px;
    padding: 18px;
    border-radius: var(--radius-md);
    background: rgba(255,255,255,0.66);
    border: 1px solid var(--border);
}

.result-box.good {
    background: var(--success-bg);
    border-color: rgba(23, 138, 76, 0.24);
}

.result-box.partial {
    background: var(--warning-bg);
    border-color: rgba(161, 92, 0, 0.24);
}

.result-title {
    margin: 0;
    font-size: 18px;
    font-weight: 900;
}

.result-text {
    margin: 6px 0 0;
    color: var(--muted);
}

.form-actions {
    display: flex;
    flex-wrap: wrap;
    gap: 12px;
    margin-top: 22px;
}

.summary-card {
    padding: clamp(24px, 5vw, 44px);
}

.summary-title {
    margin: 0;
    font-size: clamp(34px, 7vw, 68px);
    line-height: 0.95;
    letter-spacing: -0.07em;
}

.summary-subtitle {
    margin: 16px 0 0;
    color: var(--muted);
    font-size: 17px;
}

.error-card {
    padding: 22px;
    border-radius: var(--radius-md);
    background: var(--danger-bg);
    border: 1px solid rgba(180, 35, 24, 0.24);
    color: var(--danger);
}

.small-muted {
    color: var(--muted);
    font-size: 13px;
}

@media (max-width: 720px) {
    .app-shell {
        width: min(100% - 20px, 980px);
        padding: 18px 0 28px;
    }

    .app-header {
        align-items: flex-start;
        flex-direction: column;
        margin-bottom: 16px;
    }

    .header-pill {
        width: 100%;
    }

    .hero-card,
    .question-body,
    .summary-card {
        padding: 20px;
    }

    .question-top {
        flex-direction: column;
        padding: 18px 20px;
    }

    .question-progress {
        width: fit-content;
    }

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

    .btn {
        width: 100%;
    }

    .form-actions {
        flex-direction: column;
    }
}