The CSS specification defines a syntax and grammar with which the language is written. Conformance to this syntax and grammar is needed for your code to be correctly interpreted. A colon is used to separate a CSS property and its value.

```css
.element {
this: valid

this not-valid
}
```

# How do I fix this ?

Ensure that all your CSS properties have colons separating them from their values.

# Resources

* [CSS syntax](http://www.w3schools.com/css/css_syntax.asp)