body {
  font-family: "Gelasio", serif;
  background-color: gainsboro;
}
#container {
  width: 1000px;
  height: 550px;
  background-image: url(../images/crown.jpg);
  background-size: 1000px 550px;
  margin: 20px 20px;
  border-radius: 1%;
}
#calculator {
  width: 320px;
  height: 522px;
  background-color: #d9f9d9;
  margin: 10px 10px;
  position: absolute;
  top: 20px;
  border-radius: 20px;
  border: 2px darkgray solid;
}
#result {
  height: 100px;
}
#history {
  text-align: right;
  height: 30px;
  margin: 5 20px;
  padding-top: 10px;
  font-size: 15px;
  color: darkblue;
}
#output {
  text-align: right;
  height: 50px;
  margin: -25px 15px;
  font-size: 30px;
  border-bottom: 2px darkcyan dotted;
  border-radius: 2%;
}
#keyboard {
  height: 400px;
}
.operator,
.number,
.empty {
  width: 50px;
  height: 50px;
  margin: 15px;
  float: left;
  border-radius: 50%;
  border-width: 2px;
  border-color: darkblue;
  font-size: 15px;
  font-weight: bold;
}
.number,
.empty {
  background-color: #eaedef;
}
.number,
.operator {
  cursor: pointer;
}
.number:active,
.operator:active {
  font-size: 25px;
  color: red;
}
.number:focus,
.operator:focus,
.empty:focus {
  outline: 0;
}
button:nth-child(4) {
  font-size: 20;
  background-color: #20b2aa;
}
button:nth-child(8) {
  font-size: 20;
  background-color: #ffa500;
}
button:nth-child(12) {
  font-size: 20;
  background-color: #f08080;
}
button:nth-child(16) {
  font-size: 20;
  background-color: #7d93e0;
}
button:nth-child(20) {
  font-size: 20;
  background-color: #9477af;
}