@import url('https://fonts.googleapis.com/css2?family=Poppins:wght@200;300;400;500;600;700;800;900&display=swap');
*{
    font-family: 'Poppins', sans-serif;
}

body{
    background-color: black;
}

#container{
    width: 1000px;
    height: 550px;
    background-image: linear-gradient(rgba(0,0,0,0.3),rgba(0,0,0,0.3)), url(bg.jpg);
    margin: 20px auto;
}

#calculator{
 width: 320px;
 height: 520px;
 background-color: #eaedef;
 margin: 0 auto;
 top: 20px;
 position: relative;
 border-radius: 5px;
 box-shadow: 0 4px 8px 0 rgba(0, 0, 0, 0.2), 0 6px 20px 0 rgba(0, 0, 0, 0.19);
}

#result{
 height: 120px;
}

#keyboard{
 height: 400px;
}

#history{
    text-align: right;
    height: 20px;
    margin: 0 20px;
    padding-top: 20px;
    font-size: 15px;
	color: #919191;
}

#output{
	text-align: right;
	height: 60px;
	margin: 10px 20px;
	font-size: 30px;
}

.operator, .number, .empty{
	width: 50px;
	height: 50px;
	margin: 15px;
	float: left;
	border-radius: 50%;
	border-width: 0;
	font-weight: bold;
	font-size: 15px;
}

.number, .empty{
	background-color: #87c9bf;
}

.number, .operator{
	cursor: pointer;
}

.operator:active, .number:active{
	font-size: 13px;
}

.operator:focus, .number:focus, .empty:focus{
	outline: 0;
}

button:nth-child(4){
	font-size: 20px;
	background-color: #454d66;
}

button:nth-child(8){
	font-size: 20px;
	background-color: #309975;
}

button:nth-child(12){
	font-size: 20px;
	background-color: #58b368;
}

button:nth-child(16){
	font-size: 20px;
	background-color: #dad873;
}

button:nth-child(20){
	font-size: 20px;
	background-color: #f56038;
}