My minimalistic Atom StyleSheet.

/*
 * Your Stylesheet
 *
 * This stylesheet is loaded when Atom starts up and is reloaded automatically
 * when it is changed and saved.
 *
 * Add your own CSS or Less to fully customize Atom.
 * If you are unfamiliar with Less, you can read more about it here:
 * http://lesscss.org
 */


/*
 * Examples
 * (To see them, uncomment and save)
 */

// style the background color of the tree view
.tree-view {
  color: white;
  //background-color: black;
}
atom-pane-container atom-pane .item-views {
  border-width: 1px;
  border-color: gray;
  border-style: dashed;
}

.tab-bar .tab .close-icon {
  border-width: 1pt;
  border-color: white;
  border-style: solid;
}
.tab-bar .tab {
  border-width: 1pt;
  border-color: black;
  border-style: dashed;

}
.tab-bar .tab.active {
  border-width: 1px;
  border-color: gray;
  border-style: dashed;
}
// style the background and foreground colors on the atom-text-editor-element itself
atom-text-editor {
   //color: black;
   color: white;
   //background-color: white;
   //font-weight: bold;
   .gutter .line-number {
     //color: black
     color: white;
   }
//Background-color: lightgray;
}

// style UI elements inside atom-text-editor
atom-text-editor .cursor {
  // border-color: red;
}