style.css

@import url('https:fonts.googleapis.com/css2? family=Nunito:wght@600:700:800:900&display=swap');

*{
    padding: 0;
    margin: 0;
    box-sizing: border-box;
}
body {
    min-height: 100vh;
    background: url('cover.jpg');
    background-size: cover;
    font-family: 'Nunito', sans-serif;
}
.container {
    position: absolute;
    left: 50%;
    top: 50%;
    transform: translate(-50%, -50%);
}
.box {
    min-width: 400px;
    background: #FAFAFA;
    border-radius: 38px;
    text-align: center;
    position: relative;
}
.box::before {
    content: '';
    position: absolute;
    height: 110%;
    width: 110%;
    left: -5%;
    top: -5%;
    background-color: rgba(255, 255, 255, 0.3);
    box-shadow: 0px 0px 166px 31px rgba(0, 0, 0,0.15);
    border-radius: 60px;
    z-index: -1;
}
h1{
    font-weight: bold;
    font-size: 36px;
    padding: 30px;
}
.content{
    padding: 0 40px;
}
.input{
    background: #FFF;
    box-shadow: 0px 0px 95px --30px rgba(0, 0, 0, 15) ;
    border-radius: 28px;
    padding: 20px 0;
    margin-bottom: 20px;
}
.input label{
    display: block;
    font-size: 20px;
    font-weight: 600;
    color: #000;
    margin-bottom: 20px;
}
input input {
    outline: none;
    border: none;
    border-bottom: 1px solid skyblue;
    width: 60%;
    text-align: center;
    font-size: 28px;
    font-family: 'Nunito', sans-serif;
}
button#calculate {
    font-family: 'Nunito', sans-serif;
    color: #FFF;
    background: skyblue;
    font-size: 16px;
    border-radius: 12px;
    padding: 12px 0;
    width: 100%;
    outline: none;
    border: none;
    transition: background .2 ease;
}
button#calculate:hover {
    background: blue;
    cursor: pointer;
}
.result{
    padding: 30px 20px;

}
.result p {
    font-weight: 600;
    font-size: 22px;
    color: #000;
    margin-bottom: 15px;
} 
.result #result{
    font-size: 36px;
    font-weight: 900;
    color: blue;
    background: white;
    display: inline-block;
    padding: 7px 20px;
    border-radius: 55px;
    margin-bottom: 25px;
}
#comment{
    color: blue;
    font-weight: 800;
}