CSS Critique

sample.css

/*
 * CSS Critique - How many issues can you find in this stylesheet?
 */

.blue-black-select {
  background-color: white;
}

#background {
  width:100%;
  height:100%;
  left:0px;
}

#content {
 margin-left:0px !important;
 margin-top:25px !important;
}

#cb {
  padding:10px 10px;
}

#drop_down_menu {
  top:-25px;
  left:-10px;
}

#event-bar{
  padding-top:4px;
  padding-bottom:7px;
}

The class name .blue-black-select contains presentation specifics, "blue", "black".

The name "background" makes for a poor ID, because is too general of a name for something so specific.

Inconsistent naming conventions for IDs: #drop_down_menu, #event.

Inconsistent code spacing convention: #event_bar{ versus #drop_down_menu {, and background-color: white; versus width:100%;

Use of !important keyword. Almost never needed.

Use of negative values (top:-25px;) is suspect.