body {
    text-align: center;
    user-select: none;
    margin: 20px;
    background: radial-gradient(#000 1px, transparent 1px);
    background-size: 50px 50px;
}

#github-link {
    display: block;
}

#title-heading {
    font-size: 40px;
    font-family: sans-serif;
}

.container {
    display: inline-grid;
    grid-template-columns: repeat(4, 1fr);
    grid-template-rows: repeat(6, 1fr);
    width: 400px;
    height: 600px;
    border-style: solid;
    border-radius: 10px;
    padding: 10px;
    font-family: sans-serif;
    background-color: black;
    margin: 60px;
    font-size: xx-large;
}

.key, #screen {
    display: flex;
    justify-content: center;
    align-items: center;
    border: 2px solid;
    margin: 5px;
    background-color: white;
    border-color: black;
    border-radius: 20px;
    cursor: pointer;
}

.key:hover {
    border: none;
}

.number {
    background-color: gainsboro;
}

.operator {
    background-color: skyblue;
}

#screen {
    background-color: rgb(255, 250, 205);
    grid-column: 1 / end;
    grid-row: 1;
    border-radius: 10px;
    justify-content: flex-end;
    cursor: auto;
}

#display-text {
    font-size: 70px;
    margin: 0 20px;
}

#clear {
    background-color: rgb(245, 70, 70);
    color: white;
    font-size: 40px;
    grid-column: 1;
    grid-row: 2;
}

#backspace {
    background-color: rgb(160, 90, 90);
    color: white;
    font-weight: bold;
    grid-column: 2;
    grid-row: 2;
}

#nine {
    grid-column: 3;
    grid-row: 3;
}

#eight {
    grid-column: 2;
    grid-row: 3;
}

#seven {
    grid-column: 1;
    grid-row: 3;
}

#six {
    grid-column: 3;
    grid-row: 4;
}

#five {
    grid-column: 2;
    grid-row: 4;
}

#four {
    grid-column: 1;
    grid-row: 4;
}

#three {
    grid-column: 3;
    grid-row: 5;
}

#two {
    grid-column: 2;
    grid-row: 5;
}

#one {
    grid-column: 1;
    grid-row: 5;
}

#zero {
    grid-column: 2;
    grid-row: 6;
}

#dot {
    grid-column: 1;
    grid-row: 6;
}

#plus {
    grid-column: 4;
    grid-row: 4 / span 2;
}

#minus {
    grid-column: 4;
    grid-row: 3;
}

#multiply {
    grid-column: 4;
    grid-row: 2;
}

#divide {
    grid-column: 3;
    grid-row: 2;
}

#equals {
    background-color: rgb(90, 180, 90);
    grid-column: 3 / span 2;
    font-size: 50px;
    grid-row: 6;
}