:root {
    --primary-color: #006600; /* Portugal green */
    --secondary-color: #ff0000; /* Portugal red */
    --bg-color: #f4f4f9;
    --text-color: #333;
    --card-bg: #fff;
    --hover-color: #e6f2e6;
}

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

body {
    font-family: 'Inter', 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif;
    background-color: var(--bg-color);
    color: var(--text-color);
    display: flex;
    justify-content: center;
    align-items: center;
    min-height: 100vh;
    padding: 20px;
    background-image: linear-gradient(135deg, #fdfbfb 0%, #ebedee 100%);
}

.container {
    background-color: var(--card-bg);
    border-radius: 15px;
    box-shadow: 0 10px 30px rgba(0, 0, 0, 0.1);
    width: 100%;
    max-width: 600px;
    padding: 40px;
    text-align: center;
    transition: transform 0.3s ease;
}

h1 {
    font-size: 1.8rem;
    margin-bottom: 30px;
    color: var(--primary-color);
}

.options-grid {
    display: grid;
    grid-template-columns: 1fr;
    gap: 15px;
    margin-bottom: 30px;
}

.option-btn {
    background-color: #fff;
    border: 2px solid #ddd;
    border-radius: 10px;
    padding: 15px 20px;
    font-size: 1.1rem;
    cursor: pointer;
    transition: all 0.2s ease;
    text-align: left;
    color: var(--text-color);
}

.option-btn:hover {
    border-color: var(--primary-color);
    background-color: var(--hover-color);
    transform: translateY(-2px);
}

.option-btn.correct {
    background-color: #d4edda;
    border-color: #28a745;
    color: #155724;
}

.option-btn.wrong {
    background-color: #f8d7da;
    border-color: #dc3545;
    color: #721c24;
}

.option-btn:disabled {
    cursor: not-allowed;
    transform: none;
}

.progress {
    font-size: 1rem;
    color: #777;
    margin-top: 20px;
}

.hidden {
    display: none !important;
}

.reward-message {
    color: var(--secondary-color);
    font-size: 2rem;
    margin: 30px 0;
    animation: bounce 2s infinite;
}

#restart-btn {
    background-color: var(--primary-color);
    color: white;
    border: none;
    border-radius: 8px;
    padding: 15px 30px;
    font-size: 1.2rem;
    cursor: pointer;
    transition: background-color 0.2s ease;
    margin-top: 20px;
}

#restart-btn:hover {
    background-color: #004d00;
}

@keyframes bounce {
    0%, 20%, 50%, 80%, 100% {
        transform: translateY(0);
    }
    40% {
        transform: translateY(-20px);
    }
    60% {
        transform: translateY(-10px);
    }
}