.calculator {
    width: 300px;
    margin: 50px auto;
    background-color: #000000;
    border-radius: 10px;
    box-shadow: 0 5px 15px rgba(0, 0, 0, 0.5);
    padding: 20px;
    font-family: 'aria', sans-serif;
    position: fixed;
    bottom: 20px;
    left: 50%;
    transform: translateX(-50%);
}

.calculator-display {
    width: 100%;
    height: 60px;
    background-color: #000000;
    margin-bottom: 20px;
    border-radius: 5px;
    display: flex;
    justify-content: flex-end;
    align-items: center;
    padding: 0 15px;
    box-sizing: border-box;
    color: white;
    font-size: 24px;
    overflow: hidden;
}

.calculator-keys {
    display: grid;
    grid-template-columns: repeat(4, 1fr);
    grid-gap: 10px;
}

.calculator button {
    width: 60px; /* Example: Adjust as needed */
    height: 60px; /* Example: Must be equal to width for a perfect circle */
    background-color: #333333; /* Darker background for general buttons */
    border: none;
    border-radius: 50%;
    color: white;
    font-size: 22px;
    cursor: pointer;
    transition: background-color 0.2s;
    display: flex;
    justify-content: center;
    align-items: center;
}

.calculator button:hover {
    background-color: #555555;
}

.calculator .operator {
    background-color: #000000;
}

.calculator .operator:hover {
    background-color: #555555;
}

.calculator .equals {
    background-color: #0062ff; /* Blue color for equals button */
    grid-column: span 1;
}

.calculator .equals:hover {
    background-color: #a200ff;
}

.calculator .clear,
.calculator .backspace {
    background-color: #00000000; /* Darker background for clear and backspace */
}

.calculator .clear:hover,
.calculator .backspace:hover {
    background-color: #555555;
}





@media (max-width: 400px) {
    .calculator {
        width: 95%;
        margin: 0 auto;
        bottom: 2px;
        left: 50%;
        transform: translateX(-47%);
    }
}