My Atom stylesheet

styles.less

/*
 * 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 {
  // background-color: whitesmoke;
}

// style the background and foreground colors on the atom-text-editor-element itself
atom-text-editor {
  // color: white;
  // background-color: hsl(180, 24%, 12%);
}

// To style other content in the text editor's shadow DOM, use the ::shadow expression
atom-text-editor::shadow .cursor {
  // border-color: red;
}

// cf. http://marcio.io/2015/07/supercharging-atom-editor-for-go-development/
// style the background color of the tree view
.tree-view {
    font-size: 12px;
}

.list-group li:not(.list-nested-item),
.list-tree li:not(.list-nested-item),
.list-group li.list-nested-item > .list-item,
.list-tree li.list-nested-item > .list-item {
    line-height:18px;
}

.list-group .selected:before,
.list-tree .selected:before {
    height:18px;
}

.list-tree.has-collapsable-children .list-nested-item > .list-tree > li,
.list-tree.has-collapsable-children .list-nested-item > .list-group > li {
    padding-left:12px;
}

// cf. http://marcio.io/2015/07/supercharging-atom-editor-for-go-development/
.symbols-view {
  &.select-list ol.list-group li .primary-line,
  &.select-list ol.list-group li .secondary-line {
    font-size: 14px;

    // let lines wrap
    text-overflow: initial;
    white-space: initial;
    overflow: initial;

    // reduce line-height
    line-height: 1.0em;
    padding-top: .1em;
    padding-bottom: .0em;

    // make sure wrapped lines get padding
    // padding-left: 21px;
    &.icon:before {
      margin-left: -21px;
    }

    .character-match {
        color: rgb(200, 200, 10) !important;
    }
  }
}

.symbols-view {
  &.select-list ol.list-group li .secondary-line {
      float: right;
      margin-top: -12px;
      padding-top: 0em;
      padding-bottom: 0em;
      font-size: 12px;
      color: rgba(200, 200, 10, 0.8) !important;
  }
}

// cf. https://discuss.atom.io/t/please-add-padding-to-the-gutter-line-number/14324/6
atom-text-editor .gutter, atom-text-editor::shadow .gutter {
  background: transparent;
  margin-right:0.5em;
}