* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

body {
    align-content: center;
    height: 100vh;
}

.calculator {
    display: flex;
    flex-direction: column;
    gap: 5px;
    margin: auto;
    max-width: 15rem;
    min-height: 60vh;
    color: #FFFFFF;
    background-color: black;
    padding: 5px;
    border-radius: 5px;
    box-shadow: 0 5px 0 black;
}

.calculator-display {
    flex-grow: 1;
    border-radius: 5px;
    border: 1px #FFFFFF solid;
    text-align: right;
    padding: 5px;
    font-size: 2rem;
    overflow-x: scroll;
    font-family:'Segoe UI', Tahoma, Geneva, Verdana, sans-serif
}

.btn-row {
    display: flex;
}

.calculator-btn {
    border-radius: 5px;
    padding: 5px;
    margin: 1px;
    background-color: gray;
    flex-grow: 1;
    text-align: center;
    
}