body {
    display: flex;
    justify-content: center;
    align-items: center;
    min-height: 100vh;
    margin: 0;
    background-color: #222831;
}

header {
    position: absolute;
    top: 0;
    left: -2.8%;
    width: 100%;
    background-color: #16171a; 
    color: white;
    padding: 20px;
    text-align: center;
    justify-content: center;
}

header h1 {
    margin: 0;
    font-size: 46px;
}

.calculator {
    background-color: #393E46;
    border-radius: 10px;
    padding: 20px;
    font-family: 'Comic Sans MS', cursive;
    margin-top: 80px;
}

.calculator input[type="text"] {
    width: calc(100% - 20px);
    height: 40px;
    padding: 10px;
    margin-bottom: 10px;
    font-size: 18px;
    border: none;
    border-radius: 5px;
}

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

.calculator button {
    padding: 15px;
    font-size: 20px;
    border: 2px solid transparent;
    border-radius: 5px;
    background-color: #00ADB5;
    color: white;
    cursor: pointer;
    transition: all 0.3s ease;
}

.calculator button:hover {
    background-color: #00555F;
    border-color: #00ADB5;
}

/* Media Queries for responsiveness */
@media screen and (max-width: 768px) {
    .calculator {
        width: 90%;
    }
}

@media screen and (max-width: 576px) {
    .calculator {
        width: 70%;
    }
}

footer {
    position: fixed;
    bottom: 0;
    width: 100%;
    text-align: center;
    padding: 10px 0;
    /* background-color: #393E46; */
    color: white;
}