* {
    box-sizing: border-box;
}

body {
    width: 100%;
    height: 100vh;
    padding: 0;
    margin: 0;
}

#calculator {
    display: flex;
    flex-direction: column;
    align-items: center;
    justify-content: space-evenly;

    max-width: 400px;
    width: 90%;
    height: auto;
    padding: 20px;
    margin: 200px auto;
    border-radius: 8px;
    border: 1px solid grey;
}

#calculator output {
    width: 100%;
    height: 50px;
    padding: 5px;
    text-align: right;
    font-size: 25px;
    font-family: monospace;
    border-radius: 4px;
    border: 2px solid lightgrey;
}

#calculator table {
    width: 100%;
    margin: 10px;
    /* border: 1px solid red; */
}

table input[type='button'] {
    width: 100%;
    height: auto;
    padding: 10px;
    margin: 2px;
    /* margin: 0 auto; */
    outline: none;
    color: white;
    background-color: black;
    font-size: 25px;
    font-family: monospace;
    border-radius: 4px;
    border: none;
}

input[type='button']:active {
    transition: .15s ease-in;
    color: white;
    background-color: lightgreen;
    /* border: 1px solid black; */
}

#deleteBtn {
    background-color: red;
}

#calculator .operator {
    background-color: gray;
    color: white;
}

#calculator::before {
    content: ""
}