Sass Invalid CSS Error: "expected expression"

Based on your error message (error sass/test.sass) I can tell you're using the .sass extension for a Scss file. Change your file name to style.scss.

Sass and Scss use two different and incompatible syntaxes.

Try either:

/* style.scss */
#navbar {
  width: 80%;
  height: 23px;
}

Or:

/* style.sass */
#navbar 
  width: 80%
  height: 23px

Note the difference in file extension and syntax.