index.css

* {
	box-sizing: border-box;
	margin: 0;
	padding: 0;
	border: none;
}

html {
	font-size: 24px;
	font-family: "Unica One", cursive;
	background-color: rgb(228, 228, 181);
}

/* For the whole calculator */
#app {
	display: flex;
	position: relative;
	flex-direction: column;
	justify-content: center;
	align-items: center;
	height: 100%;
	padding: 1rem 0;
}

#app h1 {
	font-size: 2.5rem;
	letter-spacing: 0.5rem;
	margin-top: -25px;
	margin-bottom: 8px;
}

.calculator {
	background-color: gray;
	border: 2px solid goldenrod;
	border-radius: 10px;
}

/*For the display part (upper part) */
.display {
	display: grid;
	grid-template-columns: 1fr;
	grid-template-rows: 1fr 1fr 1fr 1fr;
	height: 20vh;
	margin: 1vw;
	border-radius: 10px;
	border: 2px solid goldenrod;
	background-color: rgb(181, 128, 231);
}

.display div {
	text-align: right;
	vertical-align: center;
	padding: 0 10px;
	padding-top: 5px;
	font-size: 3vh;
}

/* For the controls (bottom part) */
.controls {
	display: grid;
	grid-template-columns: 1fr 3fr 1fr;
	grid-template-rows: 4fr 1fr;
	grid-gap: 1vw;
	margin: 1vw;
	padding-top: 1vw;
	border-top: 1px solid black;
	width: 30vw;
	height: 60vh;
}

.leftColumn {
	display: grid;
	grid-template-columns: 1fr;
	grid-template-rows: 1fr 1fr 1fr 1fr;
	grid-gap: 1vw;
}

.leftColumn > button:nth-child(1) {
	background-color: rgb(241, 217, 241);
}

.enter {
	grid-area: 3 / 1 / 5 / 1;
	writing-mode: vertical-rl;
	text-orientation: upright;
	background-color: rgb(248, 109, 17);
}

.operations {
	grid-area: 1 / 3 / 2 / 3;
	display: grid;
	grid-template-columns: 1fr;
	grid-template-rows: repeat(4, 1fr);
	grid-gap: 1vw;
}

.operations button {
	background-color: rgb(228, 205, 77);
}

.digits {
	grid-area: 1 / 2/ 2 / 2;
	display: grid;
	grid-template-columns: repeat(3, 1fr);
	grid-template-rows: repeat(4, 1fr);
	grid-gap: 1vw;
}

.zero {
	grid-area: 4 / 1 / 4 / 3;
}

.bottom {
	grid-area: 2 / 1 / 2 / 4;
	display: grid;
	grid-template-columns: repeat(5, 1fr);
	grid-gap: 1vw;
}

.bottom button {
	background-color: rgb(120, 209, 236);
}

.clear {
	grid-column: 2 / span 2;
}

.switch {
	display: none;
}

button {
	font-family: monospace;
	font-size: 1.8vw;
	border-radius: 10px;
	box-shadow: 2px 2px 2px black;
}

button:hover {
	box-shadow: 4px 4px 4px black;
}

.digits *,
.operations * {
	font-size: 2vw;
	font-weight: bold;
}

/* For the side buttons and note ************************* */

.sideNote {
	position: fixed;
	right: 50px;
	top: 200px;
}

.sideNote button {
	display: block;
	margin: 20px;
	padding: 10px;
}

.rpnInfo {
	position: fixed;
	display: none;
	right: 30px;
	top: 100px;
	width: 30vw;
	font-family: Arial, Helvetica, sans-serif;
	font-size: 18px;
	background-color: rgb(196, 196, 43);
	padding: 20px;
	border-radius: 5px;
}

.close {
	margin-left: 350px;
	margin-top: -35px;
}