What am I doing wrong?

div {
display: inline-block;
margin-left: 5px;
height: 100px;
width: 100px;
border-radius: 100%;
border: solid;

Oops, try again. Do your

s have borders that are 2px solid black?

There are two proper ways to define a border, using a border property which has 3 values separated by spaces:

border: 4px red dashed;

or with the individual property’s:

border-width: 4px;
border-color: red;
border-style: dashed;

you seemed to have the border property with a single value, instead of 3. Also, ensure your browser zoom is set to 100%

you didn’t write: {
border: 2 px solid black;
} if this is from the classes exersize