@Robk-Blue This all depends on what you are expecting and what Notepad++ can do vs what you can do. There’s a lot of customization available to make N++ work your way, not necessarily the developer’s way. If you want to add terms to highlight, you can use Style Configurator. Select the language, say CSS and go through the list of styles. Some style types (PSEUDOCLASS is the first type on the list) allow you to add user-defined keywords. Once defined, you can use those terms in your text and they will be highlighted based on that style If you have terms that you want to have their OWN style, you can also use the EnhanceAnyLexer plugin. You pick a foreground color and then use a regular expression to define what receives that color. Last, and this is more work, you can create your own custom html-css language as a User-Defined Language. I don’t believe that you can set it as the default for .html or .css files, but you can always select it instead.