style.css

*{
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}
body{
    height: 100vh;
    display: flex;
    justify-content: center;
    align-items: center;
}
.container{
    width: 450px;
}
h1{
    color: #364547;
    margin-bottom: 0.5em;
    text-align: center;
}
.container .box{
    width: 100%;
    display: flex;
}
.box div{
    width: 100%;
}
select{
    width: 95%;
    height: 40px;
    font-size: 1em;
    cursor: pointer;
    outline: none;
    background: #7868e6;
    color: white;
    margin: 0.2em 0;
    padding: 0 1em;
    border-radius: 10px;
    border: none;
}
input{
    width: 95%;
    height: 40px;
    font-size: 1em;
    margin: 0.2em 0;
    border-radius: 10px;
    border: none;
    background: #edeef7;
    outline: none;
    padding: 0 1em;
}
.btn{
    width: 98%;
    height: 40px;
    background: #7868e6;
    color: white;
    border-radius: 10px;
    border: none;
    cursor: pointer;
    font-size: 1em;
    margin: 0.5em 0;
}
#reset{
    background: #3645479a;
}
@media (max-width: 455px) {
    .container{
        margin: 10px;
    }
}