html, body {
  height: 100%;
  margin: 0;
  padding: 0;
}

body{
    background: radial-gradient(#0e0e0e, #888888);
    font-family: Arial, Helvetica, sans-serif;
    display: flex;
    flex-direction: column;
}

header{
    display: flex;
    flex-direction: column;
    justify-content: center;
    align-items: center;
    text-align: center;
    color: white;
}

.container{
    display: flex;
    align-items: center;
    justify-content: center;
}

main{
    flex:1;
}

.base{
    border: 1px solid black;
    height: 450px;
    width: 300px;
    margin-top: 70px;
    border-radius: 25px;
    background-color: black;
    box-shadow: 2px 3px #1d1d1d;
}

.writting{
    margin: 15px;
    display: flex;
    flex-direction: column;
    align-items: flex-end;
}

.write{
    height: 50px;
    color: white;
    font-size: 35px;
    overflow: hidden;
    max-width: 100%;
}

.operation{
    height: 30px;
    color: rgb(90, 90, 90);
    font-size: 20px;
    font-weight: bold;
    margin-top: 15px;
    overflow: hidden;
    max-width: 100%;
}

.line1, .line2, .line3, .line4, .line5{
    border: 1px solid black;
    border-radius: 25px;
    margin: 12px;
    height: 50px;
    display: flex;
    justify-content: space-around;
    align-items: center;
}

button{
    border: none;
    color: white;
    font-size: 25px;
    background-color: #5c5c5e;
    border-radius: 50%;
    width: 60px;
    height: 60px;
}

.button-digit {
    background-color: #1C1C1C;
}

.button-digit:hover {
    background-color: #474747;
}

.button-operation {
    background-color: #FF9F0A;
}

.button-operation:hover {
    background-color: #f8b857;
}

button:hover{
    background-color: #88888b;
}

footer {
  background-color: #222;
  color: white;
  padding: 5px;
  text-align: center;
}

a{
    text-decoration: none;
    text-transform: none;
    color:white;
}

a:hover {
  text-decoration: underline;
  color: #e2bd43;
  font-weight: bold;
}