.popup-overlay {
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background: rgba(0, 0, 0, 0.5);
    display: none;
    justify-content: center;
    align-items: center;
    z-index: 1000;
    animation: fadeIn 0.3s ease-out;
}

.popup-container {
    background: white;
    padding: 20px;
    border-radius: 15px;
    box-shadow: 0 4px 15px rgba(0, 0, 0, 0.2);
    max-width: 400px;
    width: 90%;
    text-align: center;
    position: relative;
    animation: slideIn 0.3s ease-out;
}

.popup-close {
    position: absolute;
    top: 10px;
    right: 10px;
    border: none;
    background: none;
    font-size: 20px;
    cursor: pointer;
    color: #666;
}

.popup-icon {
    font-size: 48px;
    margin-bottom: 15px;
}

.popup-title {
    font-size: 24px;
    margin-bottom: 10px;
    color: #333;
}

.popup-message {
    margin-bottom: 20px;
    color: #666;
}

.popup-button {
    padding: 8px 20px;
    border-radius: 20px;
    border: none;
    background: #007bff;
    color: white;
    cursor: pointer;
    transition: background 0.2s;
}

.popup-button:hover {
    background: #0056b3;
}

@keyframes fadeIn {
    from { opacity: 0; }
    to { opacity: 1; }
}

@keyframes slideIn {
    from { 
        opacity: 0;
        transform: translateY(-20px);
    }
    to { 
        opacity: 1;
        transform: translateY(0);
    }
}

.difficulty-badge {
    display: inline-block;
    padding: 5px 15px;
    border-radius: 15px;
    color: white;
    font-weight: bold;
    margin-top: 10px;
}

.difficulty-easy {
    background-color: #28a745;
}

.difficulty-medium {
    background-color: #ffc107;
    color: #333;
}

.difficulty-hard {
    background-color: #dc3545;
}