Please comment on the following very simple css stylesheet, especially with regard to what essential elements and tags are missing from it.
body {
background-color: #00008b;
font-family: sans-serif;
}
div {
background-color: #7fffd4;
color: #00008b;
padding: 3%;
margin-bottom: 3%;
height: 100%;
width: 94%;
}
.title {
font-size: 300%;
text-align: center;
border-radius: 60%;
}
.textbox {
font-size: 230%;
text-align: left;
border-radius: 3%;
}
.link {
font-size: 180%;
text-align: center;
border-radius: 60%;
}