body {
    font-family: 'Arial', sans-serif;
    background: #f7f7f7;
    margin: 0;
    padding: 0;
}

.container {
    max-width: 700px;
    margin: 20px auto;
    background: #fff;
    padding: 20px 25px;
    border-radius: 10px;
    box-shadow: 0 0 15px rgba(0,0,0,0.1);
}

h1 {
    text-align: center;
    color: #333;
    margin-bottom: 20px;
    font-size: 24px;
}

.question {
    font-size: 18px;
    margin-bottom: 15px;
    color: #333;
    line-height: 1.5;
}

.options {
    list-style: none;
    padding: 0;
}

.options li {
    margin-bottom: 10px;
    border: 1px solid #ddd;
    border-radius: 5px;
    padding: 12px 15px;
    cursor: pointer;
    transition: all 0.2s ease;
    background: #fafafa;
}

.options li:hover {
    background: #f0f0f0;
}

.options li.selected {
    background-color: #e3f2fd !important;
    border-color: #2196f3;
    font-weight: bold;
}

.options li.correct {
    background-color: #d4edda !important;
    border-color: #28a745;
    color: #155724;
}

.options li.wrong {
    background-color: #f8d7da !important;
    border-color: #dc3545;
    color: #721c24;
}

.navigation {
    display: flex;
    justify-content: space-between;
    margin-top: 30px;
}

button {
    padding: 10px 20px;
    border: none;
    background-color: #007bff;
    color: #fff;
    font-size: 16px;
    border-radius: 5px;
    cursor: pointer;
    transition: 0.2s;
}

button:hover:not(:disabled) {
    background-color: #0056b3;
}

button:disabled {
    background-color: #cccccc;
    cursor: not-allowed;
}

.score {
    text-align: center;
    font-size: 24px;
    margin-top: 20px;
    color: #28a745;
    font-weight: bold;
}

@media screen and (max-width: 600px) {
    .container {
        padding: 15px 20px;
        margin: 10px;
    }
    h1 {
        font-size: 20px;
    }
    .question {
        font-size: 16px;
    }
    button {
        font-size: 14px;
        padding: 8px 15px;
    }
}