body {
  background-color: rgb(214, 214, 214);
  font-family: monospace;
}
.box {
  position: absolute;
  top: 0;
  left: 0;
  right: 0;
  bottom: 0;
  margin: auto;

  text-align: center;
  width: 270px;
  height: 450px;
  border-radius: 10px;

  background-color: rgb(214, 214, 214);
  box-shadow: 5px 5px 10px #b6a9a9, -5px -5px 10px #ffffff;
}
input {
  border: none;
  outline: none;
  text-align: right;
  padding: 15px;
  margin-bottom: 10px;
  font-size: 15px;
  font-weight: bolder;

  background: transparent;
  box-shadow: inset 2px 2px 5px #babecc, inset -5px -5px 10px #ffffff;
}

table {
  margin: auto;
}

button {
  margin: 10px 0 0 5px;
  border: none;
  width: 45px;
  height: 45px;
  outline: none;
  font-size: 18px;
  font-weight: bold;

  background: rgb(214, 214, 214);
  border-radius: 20%;
  box-shadow: 5px 5px 10px #b6acac, -5px -5px 10px #faf4f4;
}

button:active {
  box-shadow: inset 1px 1px 2px #babeec, inset -1px -1px 2px #ffffff;
}

.math {
  background: black;
  color: #ffffff;
}

#clr,
#clear {
  background: red;
  color: #ffffff;
  margin-left: 230%;
}