body {
    font-family: 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif;
    margin: 0;
    padding: 0;
    background-color: #f4f7f6;
    color: #333;
}

.container {
    max-width: 900px;
    margin: 0 auto;
    padding: 20px;
}

header {
    margin-bottom: 30px;
    display: flex;
    justify-content: space-between;
    align-items: center;
}

h1 {
    color: #2c3e50;
    margin: 0;
}

.back-link {
    text-decoration: none;
    color: #3498db;
    font-weight: 500;
}

.card {
    background: white;
    border-radius: 12px;
    padding: 30px;
    box-shadow: 0 4px 6px rgba(0,0,0,0.05);
}

.question-display {
    text-align: center;
    margin: 30px 0;
    padding: 20px;
    background-color: #fff;
    border: 1px solid #eee;
    border-radius: 8px;
}

.score-image {
    max-width: 100%;
    height: auto;
}

.options-list {
    display: flex;
    flex-direction: column;
    gap: 15px;
}

.option-container {
    display: flex;
    align-items: center;
    padding: 15px;
    border: 2px solid #e0e0e0;
    border-radius: 8px;
    cursor: pointer;
    transition: all 0.2s;
    background: white;
}

.option-container:hover {
    border-color: #3498db;
    background-color: #f8fbff;
}

.option-container.selected {
    border-color: #3498db;
    background-color: #eaf6ff;
}

.option-radio {
    margin-right: 20px;
    width: 20px;
    height: 20px;
    cursor: pointer;
}

.option-image {
    max-height: 60px;
    width: auto;
    margin-left: auto;
}

.btn {
    background-color: #3498db;
    color: white;
    border: none;
    padding: 12px 24px;
    border-radius: 6px;
    font-size: 16px;
    cursor: pointer;
    transition: background-color 0.2s;
}

.btn:hover {
    background-color: #2980b9;
}

.result-message {
    margin-top: 30px;
    padding: 20px;
    border-radius: 8px;
    text-align: center;
    font-size: 1.2em;
}

.result-correct {
    background-color: #d4edda;
    color: #155724;
    border: 1px solid #c3e6cb;
}

.result-wrong {
    background-color: #f8d7da;
    color: #721c24;
    border: 1px solid #f5c6cb;
}

.nav-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
    gap: 20px;
    margin-top: 40px;
}

.nav-card {
    background: white;
    padding: 25px;
    border-radius: 12px;
    text-decoration: none;
    color: inherit;
    box-shadow: 0 4px 6px rgba(0,0,0,0.05);
    transition: transform 0.2s, box-shadow 0.2s;
    border: 1px solid #eee;
}

.nav-card:hover {
    transform: translateY(-5px);
    box-shadow: 0 8px 15px rgba(0,0,0,0.1);
}

.nav-card h3 {
    margin-top: 0;
    color: #2c3e50;
}

.nav-card p {
    color: #7f8c8d;
    margin-bottom: 0;
}