style.css

body{
  margin:0;
  padding:0;
}
.names {
  text-align: center;
}
.names h2{
  margin-top:0px;
  font-size: 50px;
  margin-bottom: 0px;
  padding: 10px;
}
.names marquee{
   text-align: right;
   margin-bottom:-10px;
   margin-right: 12px;
   font-size: 15px ;
   font-weight: bolder;
   margin-left: 17rem;
   padding: 3px;
   border: 3px double greenyellow;
}
.Calculator {
  background: black;
  height:680px;
  width: 400px;
  color: white;
  border-radius: 25px;
  margin: auto;
  margin-top: 50px;
  border: 6px solid red;
}
#Textview{
  width: 350px;
  text-align: right;
  height: 40px;
  left: 0;
  right: 0;
  margin: 30px auto 10px auto; 
  margin-left: 8px;
  padding: 15px;
  border-radius: 10px;
  
}
input[type="text"]{
  font-size: 40px;
}

.keys{
  /*border:4px double #A4F806;*/
}
.btn{
  position: relative;
  height: 65px;
  width: 75px;
  margin: 10px;
  /*padding: 20px;*/
  border-radius: 15px;
  font-weight: bolder;
  font-size: 30px;
}
#btn-clear{
  background: red;
  color: black;
}
#btn-plus {
 position: absolute;
 width: 55px;
 height: 160px;
 background-color: greenyellow;
 color: black;
}
#btn-equal {
  position: absolute;
  width: 180px;
  height: 65px;
  background-color: greenyellow;
  color: black;
  align-items: center;
}
.btn:hover{
  background:#04F2EB;
}
#copy {
   position: fixed;
   padding: 4px;
    left: 50%;
    transform: translateX(-50%);
    margin: 0 auto 2.5px auto;
    font-size: 20px;
    color:#F20406;
    text-shadow: .5px .5px 5px #5c5859;
}