* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
    font-family: 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif;
}

body {
    height: 100vh;
    width: 100vw;
    display: flex;
    justify-content: center;
    align-items: center;
    background: linear-gradient(180deg, rgb(153, 0, 255), rgb(4, 0, 255));
    background-size: cover;
    background-repeat: no-repeat;
}

input {
    height: 90px;
    font-size: 70px;
    overflow: hidden;
    padding: 1em 0.5em;
    width: 100%;
    border-radius: 20px 20px 0 0;
    border: none;

}


#calculatorContainer {
    width: 500px;
    height: auto;
    gap: 10px;
    background-color: rgb(14, 17, 51);
    border-radius: 20px;
}

button {
    width: 100px;
    height: 100px;
    border-radius: 20px;
    border: none;
    background-color: rgba(0, 0, 0, 0.742);
    color: white;
    font-size: 3rem;
    font-weight: bolder;
    cursor: pointer;
    transition: all 0.3s ease;
}

#keys {
    display: grid;
    grid-template-columns: repeat(4, 1fr);
    gap: 10px;
    margin: 10px 0;
    padding: 1em 2em;
}

@media(max-width:637px) {
    #calculatorContainer {
        width: 90vw;
    }

    #key {
        width: 100vw;
    }

    button {
        width: 14vw;
        height: 7vh;
        display: flex;
        justify-content: center;
        align-items: center;
    }
}

@media(max-width:528px) {
    button {
        font-size: 3rem;
        width: auto;
        height: auto;
    }
}

button:hover {
    background-color: rgba(0, 0, 0, 0.442);
}

button:active {
    background-color: rgba(0, 0, 0, 0.242);
}

.operator {
    background-color: rgb(251, 243, 20);
    color: rgba(0, 0, 0, 0.732);
    transition: all 0.3s ease;
}

.operator:hover {
    background-color: white;
}

.operator:active{
    background-color: rgba(255, 255, 255, 0.796);
}