style.css

@import url('https://fonts.googleapis.com/css2?family=Open+Sans:wght@300;400;600&display=swap');


*{
  margin: 0;
  padding: 0;
  font-family: "Open Sans", sans-serif;
}

body{
  background: linear-gradient(to bottom right, #4D6AFF , #49d6f4 );
  height: 100vh;
  display: flex;
  justify-content: center;
  align-items: center;
}

.container{
  padding: 2rem;
  background: white;
  border-radius: 1rem;
  box-shadow: 5px 5px rgba(0,0,0, .2);
}

.results input{
  padding: .8rem;
  font-size: 1rem;
  padding-bottom: .3rem;
  padding-left: .3rem;
  line-height: 5px;
  border: none;
  border-bottom: 2px solid grey;
  transition: border 120ms ease-in-out;
  display: block;
  width: 90%;
}

.results input:focus, .results input:active{
  outline: none;
  border-bottom: 2px solid #4D6AFF;
}

.results span{
  display: block;
  text-align: right;
  padding: .3rem;
  padding-right: .1rem;
  margin: .5rem 0;
}

.btn-container{
  display: flex;
  justify-content: space-between;
}

.digits{
  width: 10rem;
}

.btn{
  padding: 1rem;
  font-size: 1rem;
  margin: 2px .1rem;
  background: white;
  /* border: 1px solid grey; */
  outline: none;
  border: 1px solid #d9d9d9;
  border-radius: .2rem;
  transition: background 150ms ease-in-out;
}

.btn:hover{
  background-color: rgba(80,97,255,.8);
  color: white;
  /* border: none; */
}
.zero{
  margin-left: 3.32rem;
  margin-right: .39rem;
}
.operators{
  width: 6.5rem;
}
.operators .opt{
  padding: .8rem;
  font-size: 1rem;
  margin-bottom: .5rem;
  background: white;
  outline: none;
  border: 1px solid #d9d9d9;
  border-radius: .2rem;
  transition: background 150ms ease-in-out;
}
.clear{
  margin-right: 1rem;
}

.operators .opt:hover{
  background-color: rgba(80,97,255,.8);
  color: white;
}

span{
  color: gray;
}

.equal{
  padding-left: 2rem !important;
  padding-right: 2rem !important;
}

.equal:hover{
  background-color: rgba(0,200,0,.6) !important;
  color: white;
}