* {
  margin: 0;
  padding: 0;
  box-sizing: border-box;
  outline: none;
}
body {
  display: flex;
  justify-content: center;
  align-items: center;
  min-height: 100vh;
  background: linear-gradient(#9cebfc, #6ae1fb);
}
form {
  display: flex;
  justify-content: center;
  align-items: center;
  flex-direction: column;
}
.center {
  width: 350px;
  background: black;
  border-radius: 20px;
}
input[type="text"] {
  height: 60px;
  width: 300px;
  margin-top: 40px;
  border-radius: 1px;
  border: 1px solid #e1e7ea;
  color: black;
  font-size: 22px;
  font-weight: bold;
  text-align: right;
  padding-right: 20px;
  background: #eee;
}
form .buttons {
  width: 300px;
  margin: 10px 25px 0 25px;
  padding: 10px 0;
}
input[type="button"] {
  width: 58px;
  height: 55px;
  margin: 5px;
  font-size: 22px;
  line-height: 55px;
  border-radius: 3px;
  border: 1px solid #d9d9d9;
  background: linear-gradient(#d9d9d9, #bfbfbf);
  cursor: pointer;
  transition: 0.5s;
}
input[type="button"]:hover {
  background: linear-gradient(#bfbfbf, #d9d9d9);
}
input#clear{
    background: red;
    border: 1px solid #cc0000;
    color: white;
}
input#equal{
    width: 275px;
    margin: 10px 0 10px 0;
    font-size: 30px;
    color: white;
    background: red;
    border: 1px solid red;
}