* {
  margin: 0;
  padding: 0;
  box-sizing: border-box;
}

body {
  min-height: 100vh;
  display: flex;
  justify-content: center;
  align-items: center;
}

.calculator {
  width: 300px;
  height: 500px;
  box-shadow: 4px 4px 30px black;
  border-radius: 12px;
  overflow: hidden;
  background-color: rgb(33, 33, 33);
}

form input {
  width: 100%;
  height: 150px;
  border-radius: 12px;
  border: none;
  padding: 1rem;
  font-size: 2rem;
  color: white;
  background-color: black;
  text-align: right;
  pointer-events: none;
}

.buttons {
  display: flex;
  flex-wrap: wrap;
  justify-content: space-around;
  padding: 20px;
}

button {
  /* flex: 0 0 22%; */

  margin: 5px 3px;
  border: 1px solid black;
  width: 52px;
  height: 52px;
  font-size: 22px;
  font-weight: 500;
  border-radius: 60%;
  cursor: pointer;
}

.btn_yellow {
  font-weight: 700;
  background-color: rgb(255, 153, 0);
  color: white;
}

.btn_clear {
  font-weight: 700;
  background-color: red;
}

.btn_equal {
  font-weight: 700;
  background-color: rgb(28, 227, 48);
  color: white;
}

.btn_grey {
  color: white;
  background-color: rgb(0, 0, 0);
}