style.css

*,
*:before,
*:after{
    padding: 0;
    margin: 0;
    box-sizing: border-box;
}
body{
    height: 100vh;
    background: hsla(141, 54%, 86%, 1);
    display: flex;
    align-items: center;
    justify-content: center;
    min-height: 100vh;
    padding: 30px;
    background: url(https://source.unsplash.com/E8Ufcyxz514/2400x1823) center / cover no-repeat fixed;
}
.container{
    background: rgba( 255, 255, 255, 0.25 );
    box-shadow: 0 8px 32px 0 rgba( 31, 38, 135, 0.37 );
    backdrop-filter: blur( 3.5px );
    -webkit-backdrop-filter: blur( 3.5px );
    border-radius: 10px;
    border: 1px solid rgba( 255, 255, 255, 0.18 );
    padding: 30px 30px;
    width: 400px;
    position: absolute;
    transform: translate(-50%,-50%);
    top: 50%;
    left: 50%;
    border-radius: 15px;
    font-family: 'Poppins',sans-serif;
    box-shadow: 25px 25px 30px rgba(0,0,0,0.15);
}
.container h1{
    border-radius:10px;
    padding: 15px;
box-shadow: 0 0 20px rgba(139, 140, 141, 0.25);
margin-bottom: 60px;
	color: rgb(106, 25, 163);
	text-align: center;
	font-size: 23px;
	letter-spacing: 1px;
    border: none;
    padding:10px;
    border-radius:10px 10px 0px 0px;
	margin-top: -32px;
	margin-left: -30px;
	margin-right: -30px;
	margin-bottom: 40px;
}
.row{
    display: flex;
    align-items: center;
    justify-content: space-between;
    margin-bottom: 40px;
}
.row span{
    font-weight: 500;
}
input[type="range"]{
    width: 70%;
    height: 3.5px;
    -webkit-appearance: none;
    appearance: none;
    background-color: #dcdcdc;
    border-radius: 3px;
    outline: none;
}
input[type="range"]::-webkit-slider-thumb{
    -webkit-appearance: none;
    appearance: none;
    height: 15px;
    width: 15px;
    background-color: #ce1dbc;
    border-radius: 50%;
    cursor: pointer;
}
#result{
    font-size: 30px;
    font-weight: 700;
    letter-spacing: 1px;
    text-align: center;
    color: #0be881;
}
#category{
    font-size: 18px;
    text-align: center;
    letter-spacing: 1px;
}
input#weight,input#height{
    background-color: white;
}
 
.display{
    border-radius:10px;
    padding: 15px;
box-shadow: 0 0 20px rgba(0,139,253,0.25);
margin-bottom: 60px;
background: rgba( 255, 255, 255, 0.25 );
box-shadow: 0 8px 32px 0 rgba( 31, 38, 135, 0.37 );
backdrop-filter: blur( 3.5px );
-webkit-backdrop-filter: blur( 3.5px );
}

@media screen and (max-width: 600px) {
    
    .container{
    width: 80%;
    }
  }