@charset "utf-8";
body{
	margin: 0;
	padding: 0;
	display: flex;
	justify-content: center;
	align-items: center;
	height: 100vh;
	background-color: #f0f0f0;
}
#cal{
	font-family: Arial, sans-serif;
	background-color: rgba(0, 0, 0, 0.9);
	border-radius: 20px;
	max-width: 400px;
	overflow: hidden;
	box-shadow: 2px 2px 5px black;
}
#display{
	width: 100%;
	padding: 20px;
	font-size: 5rem;
	text-align: left;
	border: none;
	color: white;
	background-color: rgba(0, 0, 15, 0.5);
}
#btn{
	display: grid;
	grid-template-columns: repeat(4, 1fr);
	gap: 10px;
	padding: 25px;
}

button{
	width: 80px;
	height: 80px;
	border-radius: 50px;
	border:none;
	color: white;
	background-color: grey;
	font-size: 3rem;
	font-weight: bold;
	cursor: pointer;
}
button:hover{
	background-color: darkgrey;
}
button:active{
	background-color: darkslategrey;
}
.operator{
	background-color: darkorange;
}
.operator:hover{
	background-color: orange;
}
.operator:active{
	background-color: darksalmon;
}