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

body {
    font-family: 'Noto Sans JP', sans-serif;
    background: #ffffff;
    color: #1a1a1a;
    min-height: 100vh;
    display: flex;
    justify-content: center;
    align-items: center;
    padding: 20px;
}

.container {
    max-width: 1000px;
    width: 100%;
}

header {
    text-align: center;
    margin-bottom: 40px;
}

h1 {
    font-size: 2.5rem;
    margin-bottom: 10px;
    font-weight: 700;
}

.subtitle {
    font-size: 1.1rem;
    color: #666;
}

.passage-container {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 30px;
    margin-bottom: 30px;
}

.passage {
    background: #f8f8f8;
    border: 2px solid #e0e0e0;
    border-radius: 12px;
    padding: 25px;
    transition: all 0.3s ease;
}

.passage:hover {
    border-color: #1a1a1a;
    transform: translateY(-2px);
    box-shadow: 0 4px 12px rgba(0,0,0,0.1);
}

.passage-label {
    font-weight: 700;
    font-size: 1.2rem;
    margin-bottom: 15px;
    color: #1a1a1a;
}

.passage-content {
    line-height: 1.8;
    margin-bottom: 20px;
    min-height: 150px;
}

.choice-btn {
    width: 100%;
    padding: 12px;
    background: #1a1a1a;
    color: white;
    border: none;
    border-radius: 8px;
    font-size: 1rem;
    font-weight: 600;
    cursor: pointer;
    transition: all 0.2s ease;
}

.choice-btn:hover {
    background: #333;
    transform: translateY(-1px);
}

.choice-btn:active {
    transform: translateY(0);
}

.choice-btn:disabled {
    background: #ccc;
    cursor: not-allowed;
    transform: none;
}

#result-container {
    text-align: center;
    padding: 30px;
    background: #f8f8f8;
    border-radius: 12px;
    margin-bottom: 30px;
}

#result-container.hidden {
    display: none;
}

#result-message {
    font-size: 1.5rem;
    font-weight: 700;
    margin-bottom: 20px;
}

#result-message.correct {
    color: #2ecc71;
}

#result-message.incorrect {
    color: #e74c3c;
}

#explanation {
    line-height: 1.8;
    margin-bottom: 25px;
    color: #333;
}

#next-btn {
    padding: 12px 40px;
    background: #1a1a1a;
    color: white;
    border: none;
    border-radius: 8px;
    font-size: 1rem;
    font-weight: 600;
    cursor: pointer;
    transition: all 0.2s ease;
}

#next-btn:hover {
    background: #333;
}

.score-container {
    text-align: center;
    font-size: 1.2rem;
    font-weight: 600;
}

.passage.correct {
    border-color: #2ecc71;
    background: #e8f8f0;
}

.passage.incorrect {
    border-color: #e74c3c;
    background: #fde8e8;
}

@media (max-width: 768px) {
    .passage-container {
        grid-template-columns: 1fr;
        gap: 20px;
    }

    h1 {
        font-size: 2rem;
    }
}