The normal Delphi IDE (for Win32) has not been designed as a IDE for the creation and layout of HTML pages, CSS (style sheets) or JavaScript code.
The Delphi IDE can create a new JavaScript file, by default it will contain only this lonely line:
// insert JavaScript source code here
The IDE will not give you any further support specific to JavaScript from this point. At least, it tells you what you have to do next :)
The IDE can also create new CSS files with this minimalistic content:
BODY {
}
That's all, no further IDE support like style preview, validation or CodeInsight. I don't know if it is possible for Delphi add-on developers to write plugins to close these gaps.
The HTML editor in Delphi IDE offers some support for tables and forms. No preview, no formatting, no CodeInsight. New files are always ANSI encoded, if you need UTF-8 you have to change it manually for every single file because the IDE does not have an option to change this default. HTML files also have the classic *.htm extension (from the old DOS era), so if you prefer the .html extension you have to fix this for every file again.
Fortunately there are many free and very comfortable editors and IDEs. For example NetBeans, it has a very small storage space footprint, and is also a good PHP development environment. And it is free. And last but not least, it is an impressive example of a GUI built with Java.