.keypad {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 8px;
    margin-bottom: 8px;
}

.keypad button {
    width: 100%;
    padding: 16px;
    font-size: 20px;
    font-weight: bold;
    background-color: white;
    border: 2px solid #4CAF50;
    border-radius: 12px;
    color: #4CAF50;
    cursor: pointer;
    user-select: none;
    -webkit-tap-highlight-color: transparent;
}

.keypad button:active {
    background-color: #4CAF50;
    color: white;
}

.keypad .delete {
    border-color: #e74c3c;
    color: #e74c3c;
}

.keypad .delete:active {
    background-color: #e74c3c;
    color: white;
}

.submit {
    width: 100%;
    padding: 15px;
    font-size: 20px;
    font-weight: bold;
    background-color: #4CAF50;
    border: none;
    border-radius: 12px;
    color: white;
    transition: background-color 0.3s;
    cursor: pointer;
}

.submit:active {
    background-color: #357a38;
}

.submit:disabled {
    background-color: #656565;
    cursor: not-allowed;
}

.replay-button {
    font-size: 20px;
    padding: 12px 40px;
    border: none;
    border-radius: 30px;
    background-color: #4CAF50;
    color: white;
    cursor: pointer;
    transition: background-color 0.3s;
    margin-top: 30px;
}

.replay-button:active {
    background-color: #357a38;
}