style.css

*{
    margin:0;
    padding: 0;
    box-sizing: border-box;
    background: url('earth.gif');
}
body{
    display: flex;
    justify-content: center;
    align-items:center ;
    min-height: 100vh;
}
.container{
    max-width:450px ;
    background: #003333;
    border-radius: 8px;
    box-shadow: 0px 0px 15px 3px rgba(0,0,0,0.5);
    font-family: sans-serif;
    padding:20px ;
}
.title{
    display: flex;
    justify-content: center;
    align-items: center;
    flex-wrap: wrap-reverse;
    gap:10px;
}
.temperature-icon{
    font-size:45px;
    color:#fff;
}
h1{
    color:#fff;
    letter-spacing: 1.2px;
    font-size: 30px;
}

#celsius, #fahrenheit, #kelvin{
    display: flex;
    justify-content:center;
    align-items: center;
    margin-top:25px;
}
input{
    flex:5;
    height: 60px;
    font-size: 20px;
    font-weight: 600;
    text-align: center;
    border:none;
    outline:none;
    border-radius:8px 0 0 8px;
    padding:0 10px;
}

input::-webkit-outer-spin-button,
input::-webkit-inner-spin-button{
    -webkit-appearance:none;
}


.icon{
    flex: 1;
    height: 60px;
    line-height: 60px;
    padding: 0 5px;
    text-align: center;
    font-size:30px;
    background: #4d5964;
    color:#fff;
    border-radius: 0 8px 8px 0;
}

.button{
    margin-top:25px;
    text-align: center;
}
.button button{
    border: none;
    outline: none;
    padding: 10px 30px;
    font-size:20px;
    font-weight: 600;
    border-radius: 3px;
    cursor:pointer;
    transition: 0.3s;
}

.button button:hover{
    background: #000;
    color:#fff;
}