:root {
    --sq-bg: #f4f6fb;
    --sq-card: #ffffff;
    --sq-surface: #f9fafc;
    --sq-text: #1f2430;
    --sq-muted: #6b7280;
    --sq-border: #e3e7ef;
    --sq-primary: #1f5eff;
    --sq-primary-soft: rgba(31, 94, 255, 0.14);
    --sq-shadow: 0 18px 40px rgba(15, 23, 42, 0.08);
    --sq-shadow-soft: 0 8px 16px rgba(15, 23, 42, 0.08);
}

body.sq-page {
    background: var(--sq-bg);
    color: var(--sq-text);
    min-height: 100vh;
}

body.sq-page.sq-infinite {
    --sq-primary: #e63946;
    --sq-primary-soft: rgba(230, 57, 70, 0.18);
}

body.sq-page.sq-infinite .sq-hero__icon,
body.sq-page.sq-infinite .sq-header__icon {
    background: rgba(230, 57, 70, 0.16);
    color: #a61c2a;
}

body.sq-page.sq-infinite .sq-difficulty-btn.is-selected {
    box-shadow: 0 0 0 3px rgba(230, 57, 70, 0.2);
}

body.sq-page.sq-infinite .sq-option.is-correct {
    border-color: #10b981;
    background: rgba(16, 185, 129, 0.12);
    color: #059669;
}

body.sq-page.sq-infinite .sq-option.is-wrong {
    border-color: #ef4444;
    background: rgba(239, 68, 68, 0.12);
    color: #dc2626;
}

body.dark-mode {
    --sq-bg: #0f1116;
    --sq-card: #171a21;
    --sq-surface: #1f2430;
    --sq-text: #e5e7eb;
    --sq-muted: #9aa2b1;
    --sq-border: #2b3340;
    --sq-primary: #4f8cff;
    --sq-primary-soft: rgba(79, 140, 255, 0.18);
    --sq-shadow: 0 18px 40px rgba(0, 0, 0, 0.4);
    --sq-shadow-soft: 0 8px 16px rgba(0, 0, 0, 0.35);
}

.sq-page__inner {
    max-width: 640px;
    margin: 0 auto;
    padding: 24px 16px 8px;
    display: flex;
    flex-direction: column;
    gap: 20px;
}

.sq-shell {
    position: relative;
    display: grid;
    gap: 20px;
}

.sq-onboarding {
    background: var(--sq-card);
    border-radius: 20px;
    border: 1px solid var(--sq-border);
    box-shadow: var(--sq-shadow);
    padding: 32px 24px;
    text-align: center;
    transition: opacity 0.25s ease, transform 0.25s ease;
}

.sq-hero {
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: 12px;
}

.sq-hero__icon {
    width: 64px;
    height: 64px;
    border-radius: 18px;
    background: var(--sq-primary-soft);
    display: inline-flex;
    align-items: center;
    justify-content: center;
    font-size: 30px;
}

.sq-hero__title {
    font-size: 26px;
    font-weight: 800;
    margin: 0;
}

.sq-hero__subtitle {
    font-size: 15px;
    color: var(--sq-muted);
    margin: 0;
}

.sq-hero__chips {
    display: flex;
    flex-wrap: wrap;
    justify-content: center;
    gap: 8px;
    margin-top: 8px;
}

.sq-difficulty-select {
    display: flex;
    gap: 10px;
    flex-wrap: wrap;
    justify-content: center;
    margin-top: 16px;
}

.sq-difficulty-btn {
    padding: 10px 16px;
    border-radius: 999px;
    border: 1px solid var(--sq-border);
    background: var(--sq-surface);
    color: var(--sq-text);
    font-size: 14px;
    font-weight: 600;
    cursor: pointer;
    transition: all 0.2s ease;
}

.sq-difficulty-btn:hover {
    border-color: var(--sq-primary);
    background: var(--sq-primary-soft);
}

.sq-difficulty-btn.is-selected {
    border-color: var(--sq-primary);
    background: var(--sq-primary);
    color: #fff;
}

.sq-chip {
    padding: 6px 12px;
    border-radius: 999px;
    background: var(--sq-surface);
    border: 1px solid var(--sq-border);
    font-size: 12px;
    color: var(--sq-text);
}

.sq-hero__cta {
    width: 100%;
    max-width: 260px;
    margin-top: 12px;
}

.sq-game {
    opacity: 0;
    transform: translateY(12px) scale(0.98);
    pointer-events: none;
    transition: opacity 0.3s ease, transform 0.3s ease;
}

.sq-shell.is-transitioning #sqOnboarding {
    opacity: 0;
    transform: translateY(-8px) scale(0.98);
}

.sq-shell.is-started #sqGame {
    opacity: 1;
    transform: translateY(0) scale(1);
    pointer-events: auto;
}

.sq-header {
    position: sticky;
    top: 80px;
    background: var(--sq-card);
    border-radius: 16px;
    border: 1px solid var(--sq-border);
    box-shadow: var(--sq-shadow-soft);
    padding: 16px;
    z-index: 5;
}

.sq-header__row {
    display: flex;
    align-items: center;
    justify-content: space-between;
    gap: 12px;
}

.sq-header__left {
    display: flex;
    align-items: center;
    gap: 12px;
}

.sq-header__icon {
    width: 44px;
    height: 44px;
    border-radius: 12px;
    background: var(--sq-primary-soft);
    display: inline-flex;
    align-items: center;
    justify-content: center;
    font-size: 20px;
}

.sq-header__title {
    font-size: 18px;
    font-weight: 700;
    line-height: 1.2;
}

.sq-header__subtitle {
    font-size: 12px;
    color: var(--sq-muted);
    margin-top: 2px;
}

.sq-header__right {
    text-align: right;
}

.sq-header__label {
    font-size: 12px;
    color: var(--sq-muted);
    display: block;
}

.sq-header__value {
    font-size: 20px;
    font-weight: 700;
    letter-spacing: -0.2px;
}

.sq-header__stats {
    display: grid;
    grid-template-columns: repeat(2, minmax(0, 1fr));
    gap: 12px;
    margin-top: 14px;
}

.sq-stat {
    padding: 12px 14px;
    background: var(--sq-surface);
    border-radius: 12px;
    border: 1px solid var(--sq-border);
}

.sq-stat__label {
    font-size: 12px;
    color: var(--sq-muted);
    margin-bottom: 6px;
}

.sq-stat__value {
    font-size: 22px;
    font-weight: 700;
}

.sq-card {
    background: var(--sq-card);
    border-radius: 16px;
    border: 1px solid var(--sq-border);
    box-shadow: var(--sq-shadow);
    padding: 22px;
}

.sq-card__title {
    font-size: 16px;
    font-weight: 700;
    margin-bottom: 14px;
}

.sq-question__meta {
    display: flex;
    align-items: center;
    justify-content: space-between;
    gap: 12px;
    margin-bottom: 12px;
}

.sq-difficulty,
.sq-difficulty__score {
    display: inline-flex;
    align-items: center;
    gap: 6px;
    padding: 6px 12px;
    border-radius: 999px;
    border: 1px solid var(--sq-border);
    background: var(--sq-surface);
    font-size: 13px;
    font-weight: 600;
    color: var(--sq-text);
}

.sq-difficulty__score {
    color: var(--sq-primary);
}

.sq-question {
    font-size: 18px;
    font-weight: 600;
    line-height: 1.6;
    margin-bottom: 20px;
    padding: 16px;
    background: var(--sq-surface);
    border-radius: 12px;
    border: 1px solid var(--sq-border);
}

.sq-options {
    display: flex;
    flex-direction: column;
    gap: 12px;
    margin-bottom: 16px;
}

.sq-option {
    width: 100%;
    padding: 16px 18px;
    border-radius: 12px;
    border: 2px solid var(--sq-border);
    background: var(--sq-card);
    color: var(--sq-text);
    font-size: 15px;
    font-weight: 500;
    text-align: left;
    cursor: pointer;
    transition: all 0.2s ease;
}

.sq-option:hover:not(:disabled) {
    border-color: var(--sq-primary);
    background: var(--sq-primary-soft);
    transform: translateY(-1px);
}

.sq-option:disabled {
    cursor: not-allowed;
}

.sq-option.is-correct {
    border-color: #10b981;
    background: rgba(16, 185, 129, 0.12);
    color: #059669;
}

.sq-option.is-wrong {
    border-color: #ef4444;
    background: rgba(239, 68, 68, 0.12);
    color: #dc2626;
}

body.dark-mode .sq-option.is-correct {
    color: #34d399;
}

body.dark-mode .sq-option.is-wrong {
    color: #fca5a5;
}

.sq-message {
    margin-top: 12px;
}

.message {
    padding: 12px;
    border-radius: 10px;
    font-size: 14px;
    font-weight: 600;
    text-align: center;
}

.message.correct {
    background: rgba(16, 185, 129, 0.18);
    color: #0f766e;
}

.message.wrong {
    background: rgba(239, 68, 68, 0.16);
    color: #b91c1c;
}

body.dark-mode .message.correct {
    color: #34d399;
}

body.dark-mode .message.wrong {
    color: #fca5a5;
}

.sq-actions {
    margin-top: 16px;
    display: flex;
    flex-direction: column;
    gap: 12px;
}

.sq-input {
    width: 100%;
    padding: 14px 16px;
    border-radius: 12px;
    border: 1px solid var(--sq-border);
    font-size: 15px;
    background: var(--sq-card);
    color: var(--sq-text);
    transition: border-color 0.2s ease, box-shadow 0.2s ease;
}

.sq-input:focus {
    outline: none;
    border-color: var(--sq-primary);
    box-shadow: 0 0 0 3px var(--sq-primary-soft);
}

.sq-actions__buttons {
    display: flex;
    gap: 12px;
}

.sq-btn {
    flex: 1;
    padding: 14px 16px;
    border-radius: 12px;
    border: 1px solid transparent;
    font-size: 15px;
    font-weight: 700;
    cursor: pointer;
    transition: transform 0.15s ease, box-shadow 0.15s ease, background-color 0.15s ease, color 0.15s ease;
}

.sq-btn--primary {
    background: var(--sq-primary);
    color: #ffffff;
    box-shadow: 0 8px 18px rgba(31, 94, 255, 0.25);
}

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

.sq-btn--ghost {
    background: transparent;
    color: var(--sq-primary);
    border-color: var(--sq-primary);
}

.sq-btn--ghost:hover {
    background: var(--sq-primary-soft);
}

.sq-btn:disabled {
    opacity: 0.5;
    cursor: not-allowed;
    box-shadow: none;
    transform: none;
}

.sq-result__header {
    text-align: center;
    margin-bottom: 16px;
}

.sq-result__header h2 {
    font-size: 22px;
    margin-bottom: 8px;
}

.sq-result__score {
    font-size: 26px;
    font-weight: 700;
    color: var(--sq-primary);
}

.sq-result__summary {
    font-size: 14px;
    color: var(--sq-muted);
    margin-top: 8px;
}

.sq-result__details {
    background: var(--sq-surface);
    border-radius: 12px;
    border: 1px solid var(--sq-border);
    padding: 16px;
    margin-bottom: 16px;
}

.sq-result__title {
    font-size: 14px;
    margin-bottom: 12px;
    color: var(--sq-muted);
}

.sq-result__item {
    padding: 12px 0;
    border-bottom: 1px solid var(--sq-border);
    font-size: 14px;
}

.sq-result__item:last-child {
    border-bottom: none;
}

.sq-result__question {
    display: flex;
    align-items: flex-start;
    gap: 8px;
    margin-bottom: 6px;
    font-weight: 500;
}

.sq-result__meta {
    margin-left: 24px;
    font-size: 13px;
    color: var(--sq-muted);
    margin-bottom: 6px;
}

.sq-result__icon {
    font-size: 16px;
    font-weight: 700;
    flex-shrink: 0;
    margin-top: 2px;
}

.sq-result__icon.correct {
    color: #10b981;
}

.sq-result__icon.wrong {
    color: #ef4444;
}

body.dark-mode .sq-result__icon.correct {
    color: #34d399;
}

body.dark-mode .sq-result__icon.wrong {
    color: #fca5a5;
}

.sq-result__answer {
    display: flex;
    flex-direction: column;
    gap: 4px;
    margin-left: 24px;
    font-size: 13px;
}

.sq-result__score {
    color: var(--sq-primary);
    font-weight: 600;
}

.sq-result__your-answer {
    color: var(--sq-muted);
}

.sq-result__correct-answer {
    color: #10b981;
    font-weight: 500;
}

body.dark-mode .sq-result__correct-answer {
    color: #34d399;
}

.sq-info {
    max-width: 720px;
    margin: 32px auto 0;
    padding: 24px 20px;
    background: var(--sq-card);
    border-radius: 16px;
    border: 1px solid var(--sq-border);
    box-shadow: var(--sq-shadow-soft);
    text-align: center;
}

.sq-info h3 {
    font-size: 18px;
    margin-bottom: 12px;
}

.sq-info p {
    font-size: 14px;
    color: var(--sq-muted);
    line-height: 1.7;
}

@media (max-width: 640px) {
    .sq-page__inner {
        padding: 20px 14px 8px;
    }

    .sq-onboarding {
        padding: 28px 18px;
    }

    .sq-hero__title {
        font-size: 22px;
    }

    /* 게임 진행 중 헤더: 타이틀/아이콘 숨기고 점수·진행만 컴팩트하게 */
    .sq-header {
        padding: 8px 12px;
        top: 70px;
    }

    .sq-header__left {
        display: none;
    }

    .sq-header__row {
        display: none;
    }

    .sq-header__stats {
        display: flex;
        flex-direction: row;
        gap: 8px;
        margin-top: 0;
        grid-template-columns: unset;
    }

    .sq-stat {
        flex: 1;
        padding: 6px 10px;
        border-radius: 8px;
    }

    .sq-stat__label {
        font-size: 11px;
        margin-bottom: 2px;
    }

    .sq-stat__value {
        font-size: 18px;
    }

    .sq-actions__buttons {
        flex-direction: column;
    }

    .sq-btn {
        width: 100%;
    }
}

@media (prefers-reduced-motion: reduce) {
    .sq-onboarding,
    .sq-game,
    .sq-shell.is-transitioning #sqOnboarding,
    .sq-shell.is-started #sqGame,
    .sq-hint,
    .sq-btn,
    .sq-input {
        transition: none;
    }
}