Observations

Normalization

Color codes are not all written the same way. And there is no color scheme defined.

/* Styles extracted from the current CSS */
#debug-bar span.ci-label .badge.active {
  background-color: red;
}
#debug-bar button:hover {
  background-color: #eaeaea;
}
#debug-bar table strong {
  font-weight: 500;
  color: rgba(0, 0, 0, 0.3);
}

Some other elements are not using the same units too.

/* Styles extracted from the current CSS */
#debug-bar span.ci-label .badge {
  /* ... */
  border-radius: 10rem;
  /* ... */
}
#debug-bar button {
  /* ... */
  border-radius: 4px;
  /* ... */
}

/* Styles extracted from the current CSS */
#debug-bar span.ci-label img {
  /* ... */
  margin: 6px 3px 6px 0;
  /* ... */
}

#debug-bar span.ci-label .badge {
  /* ... */
  margin-left: 0.5em;
  /* ... */
}

File structure

The CSS file is not optimized in terms of organization.

/* Styles extracted from the current CSS (same order) */

/* Line 44 ... */
#debug-bar h1,
#debug-bar h2,
#debug-bar h3 {
  font-family: "Helvetica Neue", Helvetica, Arial, sans-serif;
  color: #666;
  line-height: 1.5;
}

/* Line 58 ... */
#debug-bar a {
  text-decoration: none;
}

/* Line 100 ... Here we go again with h1 */
#debug-bar h1 {
  font-size: 16px;
  line-height: 36px;
  font-weight: 500;
  margin: 0 16px 0 0;
  padding: 0;
  text-align: left;
  display: inline-block;
  position: absolute;
  right: 30px;
  top: 0;
  bottom: 0;
}
#debug-bar-link {
  /* ... */
  /* We have a "debug-bar-link" */
  /* In the middle of titles */
  /* And what about the "#debug-bar a" above ? */
  /* Didn't we set already the styles for the links ? */
  /* Or is it just a "vocabulary" issue ? */
}
#debug-bar h2 {
  /* ... */
  /* We continue with titles now */
  /* Already set above too */
}
#debug-bar h2 span {
  /* ... */
}
#debug-bar h3 {
  /* ... */
}

Cross-browsers support

The CSS file is not optimized in terms of compatibility between browsers, old as well as recent. There are no “webkit” properties.

/* Styles extracted from the current CSS */
#debug-bar button {
  /* ... */
  border-radius: 4px;
  /* ... */
}

/* Cross-browsers optimization */
#debug-bar button {
  /* ... */
  -webkit-border-radius: 4px;
     -moz-border-radius: 4px;
          border-radius: 4px;
  /* ... */
}

Interferences

Some styles are duplicated and defined twice.

/* Styles extracted from the current CSS */
  #debug-bar h1,
  #debug-bar h2,
  #debug-bar h3 {
    font-family: "Helvetica Neue", Helvetica, Arial, sans-serif;
    color: #666;
    line-height: 1.5;  /* FIRST TIME */
  }

  #debug-bar h1 {
    font-size: 16px;
    line-height: 36px; /* SECOND TIME - NOT THE SAME UNIT */
    font-weight: 500;
    margin: 0 16px 0 0;
    padding: 0;
    text-align: left;
    display: inline-block;
    position: absolute;
    right: 30px;
    top: 0;
    bottom: 0;
  }