:root {
    --primary: #2563eb;
    --primary-light: #3b82f6;
    --secondary: #fbbf24;
    --bg: #f9fafb;
    --white: #fff;
    --gray: #6b7280;
    --gray-light: #e5e7eb;
    --success: #22c55e;
    --error: #ef4444;
    --font-main: 'Noto Sans TC', 'Segoe UI', Arial, sans-serif;
}

* {
    box-sizing: border-box;
}

body {
    font-family: var(--font-main);
    background: var(--bg);
    color: #222;
    margin: 0;
    min-height: 100vh;
    line-height: 1.7;
}

header {
    background: var(--primary);
    color: var(--white);
    padding: 2rem 1rem 1rem 1rem;
    text-align: center;
    border-radius: 0 0 20px 20px;
}

.subtitle {
    font-size: 1.1rem;
    color: var(--secondary);
    margin-top: 0.5rem;
}

main {
    max-width: 700px;
    margin: 2rem auto;
    background: var(--white);
    border-radius: 16px;
    padding: 2rem;
    box-shadow: none;
}

#score-section {
    text-align: center;
    margin-bottom: 2rem;
}

#score-section h2 {
    font-size: 2.1rem;
    color: var(--primary);
    margin-bottom: 0.5rem;
}

#summary {
    margin-top: 1rem;
    font-size: 1.1rem;
    color: var(--gray);
}

#quiz-form {
    margin-bottom: 2rem;
}

ol#question-list {
    padding-left: 1.2rem;
}

.question-block {
    margin-bottom: 2.2rem;
    padding: 1.2rem 1rem;
    border-radius: 10px;
    background: var(--bg);
    border: 2px solid var(--gray-light);
    transition: border 0.2s;
}

.question-title {
    font-size: 1.13rem;
    font-weight: 700;
    margin-bottom: 0.7rem;
    color: var(--primary);
    letter-spacing: 0.01em;
}

.options {
    display: flex;
    flex-direction: column;
    gap: 0.7rem;
}

.option label {
    cursor: pointer;
    display: flex;
    align-items: center;
    padding: 0.55rem 0.85rem;
    border-radius: 7px;
    font-size: 1.08rem;
    background: var(--white);
    border: 1.5px solid var(--gray-light);
    transition: background 0.2s, border 0.2s;
}

.option input[type="radio"] {
    margin-right: 0.7rem;
    accent-color: var(--primary);
    width: 1.1em;
    height: 1.1em;
}

.option label:hover, .option input:focus + label {
    background: #e0e7ff;
    border-color: var(--primary-light);
}

button#submit-btn {
    background: var(--primary);
    color: var(--white);
    border: none;
    padding: 0.95rem 2.5rem;
    font-size: 1.15rem;
    border-radius: 8px;
    cursor: pointer;
    font-weight: 700;
    transition: background 0.2s, transform 0.1s;
    margin-top: 1.5rem;
    display: block;
    margin-left: auto;
    margin-right: auto;
    letter-spacing: 0.03em;
}
button#submit-btn:hover, button#submit-btn:focus {
    background: var(--primary-light);
    transform: translateY(-2px) scale(1.03);
}

.analysis-block {
    background: #f1f5f9;
    border-radius: 8px;
    padding: 1rem 1.2rem;
    margin-top: 1rem;
    border-left: 6px solid var(--primary);
    font-size: 1.04rem;
    display: none;
    flex-direction: column;
    gap: 0.4rem;
}

.analysis-block.correct {
    border-left-color: var(--success);
    background: #e6fbe9;
    display: block;
}

.analysis-block.incorrect {
    border-left-color: var(--error);
    background: #fef2f2;
    display: block;
}

.analysis-title {
    font-weight: bold;
    color: var(--primary);
    margin-bottom: 0.3rem;
}

.analysis-correct {
    color: var(--success);
    font-weight: bold;
    font-size: 1.08rem;
}

.analysis-incorrect {
    color: var(--error);
    font-weight: bold;
    font-size: 1.08rem;
}

footer {
    text-align: center;
    color: var(--gray);
    font-size: 0.95rem;
    margin-top: 3rem;
    padding-bottom: 1.5rem;
}

.hidden {
    display: none !important;
}

@media (max-width: 900px) {
    main { padding: 1.2rem; }
}
@media (max-width: 600px) {
    main {
        padding: 0.7rem;
        border-radius: 0;
    }
    header {
        padding: 1.2rem 0.5rem 0.8rem 0.5rem;
        border-radius: 0 0 12px 12px;
    }
    .question-block, .analysis-block {
        padding: 0.8rem 0.5rem;
    }
    #score-section h2 { font-size: 1.3rem; }
}

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