Highlighting of variable declaration hard to see

[georgwittberger]

Highlighting of the declaration of a variable is hard to see because the variable name is only surrounded by a thin border instead of using a (semi-transparent) background color.

Example for JavaScript:

let foo = 'Hello World'
console.log(foo)

Assuming the cursor is set on the usage of foo in the console log function. The usage is highlighted with a green background which is alright but the declaration on the first line is only indicated by a thin border.

Suggestion: Highlight the declaration using a background color different from the usage background color.