body {
    font-family: Arial, sans-serif;
    display: flex;
    justify-content: center;
    align-items: center;
    min-height: 100vh;
    margin: 0;
    padding: 20px;
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    box-sizing: border-box;
}

.container {
    text-align: center;
    padding: 30px;
    background: white;
    border-radius: 20px;
    box-shadow: 0 10px 30px rgba(0,0,0,0.2);
    width: 100%;
    max-width: 500px;
    box-sizing: border-box;
}

#mainButton {
    padding: 18px 30px;
    font-size: 1.3em;
    font-weight: bold;
    border: none;
    border-radius: 15px;
    cursor: pointer;
    transition: all 0.3s ease;
    color: white;
    width: 100%;
    max-width: 280px;
    min-height: 60px;
    box-sizing: border-box;
    display: block;
    margin: 0 auto;
}

#mainButton.hidden {
    display: none;
}

.completion-buttons {
    display: none;
    gap: 15px;
    flex-direction: column;
    align-items: center;
}

.completion-buttons.show {
    display: flex;
    justify-content: center;
    align-items: center;
}

.completion-btn {
    padding: 15px 25px;
    font-size: 1.1em;
    font-weight: bold;
    border: none;
    border-radius: 12px;
    cursor: pointer;
    transition: all 0.3s ease;
    color: white;
    width: 200px;
    min-height: 50px;
    box-sizing: border-box;
}

/* Tablet and larger screens */
@media (min-width: 768px) {
    body {
        padding: 40px;
    }
    
    .container {
        padding: 40px;
    }
    
    #mainButton {
        padding: 20px 40px;
        font-size: 1.5em;
        min-width: 250px;
        width: auto;
    }
    
    .completion-buttons {
        flex-direction: row;
        gap: 20px;
    }
    
    .completion-btn {
        padding: 15px 30px;
        font-size: 1.2em;
        width: 180px;
    }
}

.completion-btn.completed {
    background: linear-gradient(45deg, #4CAF50, #45a049);
}

.completion-btn.completed:hover {
    background: linear-gradient(45deg, #45a049, #3d8b40);
    transform: translateY(-2px);
    box-shadow: 0 5px 15px rgba(0,0,0,0.3);
}

.completion-btn.attempted {
    background: linear-gradient(45deg, #ff6b6b, #ee5a52);
}

.completion-btn.attempted:hover {
    background: linear-gradient(45deg, #ee5a52, #e74c3c);
    transform: translateY(-2px);
    box-shadow: 0 5px 15px rgba(0,0,0,0.3);
}

#mainButton.practice {
    background: linear-gradient(45deg, #4CAF50, #45a049);
}

#mainButton.practice:hover {
    background: linear-gradient(45deg, #45a049, #3d8b40);
    transform: translateY(-2px);
    box-shadow: 0 5px 15px rgba(0,0,0,0.3);
}

#mainButton:active {
    transform: translateY(0);
    box-shadow: 0 2px 10px rgba(0,0,0,0.2);
}

#mainButton:disabled,
.completion-btn:disabled {
    opacity: 0.6;
    cursor: not-allowed;
    transform: none !important;
}

.completion-btn:active {
    transform: translateY(0);
    box-shadow: 0 2px 10px rgba(0,0,0,0.2);
}