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

body{
  background-color: #a7b5c1;
}


.container {
  max-width: 400px;
  margin: auto;
  height: auto;
  box-shadow: 10px 10px 10px rgb(131, 131, 125);
  background: silver;
  margin-top: 10vh;
  border-radius: 20px;
}

#heading{
 text-align: center;
 font-size: 20px;
}

#heading h6{
  margin-top: 3px;
}

.container #input {
  position: relative;
  height: 100px;
  width: 90%;
  line-height: 80px;
  text-align: right;
  padding: 10px 20px;
  outline: none;
  color: white;
  font-size: 3rem;
  border-radius: 10px;
  border: 2px solid #27615aee;
  background: rgb(51, 108, 131);
  font-family: "Lucida Sans", "Lucida Sans Regular", "Lucida Grande",
    "Lucida Sans Unicode", Geneva, Verdana, sans-serif;
  margin-left: 20px;
  margin-top:20px;
}

#buttons {
  display: grid;
  grid-template-columns: 1fr 1fr 1fr 1fr;
  margin-top: 20px;
  place-items: center;
}

#buttons button {
  height: 60px;
  width: 60px;
  margin-top: 5px;
  font-size: 1.5em;
  place-content: center;
  border-radius: 10px;
  margin-bottom: 5px;
  cursor: pointer;
  background: white;
  box-shadow: 2px 2px 2px 2px rgba(3, 240, 220, 0.918);
}

.container button:hover {
  color: rgb(197, 12, 12);
  background: black;
}

.operand {
  color: rgb(21 255 0);
  background: rgb(189, 185, 185);
  font-weight: bold;
}

#clr,
#ans {
  color: #f73c01;
}