stylesheet.css

* {
  margin: 0;
  padding: 0;
  box-sizing: border-box;
  font-family: sans-serif;
  font-weight: bold;
}

body {
  width: 100%;
  height: 100vh;
  display: flex;
  justify-content: center;
  align-items: center;
  background: url(image.svg);
  background-size: cover;
}

.calculator {
  padding: 20px;
  border: 2px solid #000;
  border-radius: 16px;
  box-shadow: 0px 3px 15px rgba(227, 231, 2, 0.8);
  background: rgba(0, 0, 0, 0.5);
}

input {
  width: 320px;
  padding: 27px;
  margin: 10px;
  background: rgba(255, 255, 255, 0.552);
  box-shadow: inset 0px 0px 8px rgba(223, 219, 7, 0.4);
  font-size: 68px;
  text-align: right;
  color: rgb(183, 49, 49);
  border: solid 2px rgba(0, 0, 0, 0.3);
  border-radius: 16.5px;
  text-shadow: 0px 1px 5px rgba(0, 0, 0, 0.2);
}

input::placeholder {
  color: black;
}

button {
  width: 60px;
  height: 60px;
  margin: 10px;
  color: #fff;
  background: rgba(0, 0, 0, 0.7);
  font-size: 26px;
  cursor: pointer;
  border: solid 1px rgba(236, 15, 15, 0.2);
  border-radius: 25px;
  text-shadow: 0px 1px 5px rgba(0, 0, 0, 0.2);
  box-shadow: -1px 2px 10px rgba(0, 0, 0, 0.5);
}

.ac,
.del {
  font-size: 22px;
}

button:hover {
  color: #fff;
  background: rgb(246, 214, 7);
}

.equalBtn {
  background: gold;
}

.operator {
  color: gold;
}