Semi-oval with CSS

Question

I'm trying to create a mix between an oval and a semi-circle.

Semi-circles can be created as such in CSS:

.halfCircle{
     height:45px;
     width:90px;
     border-radius: 90px 90px 0 0;
     -moz-border-radius: 90px 90px 0 0;
     -webkit-border-radius: 90px 90px 0 0;
     background:green;
}

And ovals can be made like this:

.oval { 
    background-color: #80C5A0;
    width: 400px;
    height: 200px;
    margin: 100px auto 0px;
    border-radius: 200px / 100px;
}

But how can I make a semi-oval? Here's my attempt so far. The problem that happens is I've got flat tops, found here. Thanks!

Answer 1

I've updated your demo with one possible solution:

div {
  background-color: #80C5A0;
  width: 400px;
  height: 100px;
  border-radius: 50% / 100%;
  border-bottom-left-radius: 0;
  border-bottom-right-radius: 0;
}

<div></div>

By using percentage based units for the border-radius it should always keep a smooth semi-ellipse regardless of your width and height values.

With a few minor changes, here's how you'd render the semi-ellipse split in half vertically:

div {
  background-color: #80C5A0;
  width: 400px;
  height: 100px;
  border-radius: 100% / 50%;
  border-top-left-radius: 0;
  border-bottom-left-radius: 0;
}

<div></div>

Answer 2

http://jsfiddle.net/QGtzW/4/

.halfOval { 
    background-color: #a0C580;
    width: 400px;
    height: 100px;
    margin: 100px auto 0px;

    /* top-right top-left bottom-left bottom-right */
    /* or from 10.30 clockwise */
    border-radius: 50% 50% 0 0/ 100% 100% 0 0;
}