*{
    margin:0;
    padding: 0;
    box-sizing: border-box;
    font-family:'Segoe UI', Tahoma, Geneva, Verdana, sans-serif;
}

body{
    width: 100%;
    height: 90vh;
    display: flex;
    justify-content: center;
    align-items: center;
    background-color: rgb(255, 255, 255) ;

}
.calculator {
    border: 1px solid #ffffff;
    padding: 20px;
    border-radius: 16px;
    background-color: rgb(112, 108, 108);
    box-shadow: 0px 3px 15px;
}

input {
    width: 100%;
    color: #fff;
    font-family:Arial, Helvetica, sans-serif;
    position: relative;
    border: none;
    padding: 24px 5px 24px 0px;
    background: rgba(150, 224, 150, 0.344);
    font-size: 20px;
    font-weight: 900;
    text-align: right;
    cursor: pointer;
}

input::placeholder{
    color: #fff;

}
button{
    border: none;
    width: 50px;
    height: 50px;
    margin: 10px;
    border-radius: 25%;
    background: black;
    color: #fff;
    font-size: 20px;
    cursor: pointer;
    
}

.equalbtn{
    background-color: rgb(28 78 30);
}
.operator{
    color: rgb(255, 255, 255);
    background-color: #630909;
}

.author{
    position: absolute;
    bottom: 10%;
    /* color: #fff; */
}
.author h1{
    font-family:Arial, Helvetica, sans-serif;
    color: #000000;
}
@media only screen and (min-width:320px )and (max-width:720px) {
    
    button{
        width: 50px;
        height: 50px;   
    }
    
}