how to remove the white space between two span tags?

Answer 1

Change your CSS like this - this should work.

.text-admin{
  display: inline-block;
  margin-left: -5px;
}

elements are inline-elements, means that it's width depends on it's content. Paddings and margins aren't applied. To "enable" support for margins and paddings, you have to change the span to render as inline-block element. (with display: inline-block;). After this you can apply a negative margin of e.g. 4px to reduce the gap between your elements.