when i attach a classs in bootstrap for example
<header class="panel-head container">
am i calling 2 separate classes i.e. "panel-head" and "container"
or is it just one class . also my secound question is if i am calling 2 separate classes , are they already predefined in bootstrap (ok i know container is but what about panel-head) ???
Why ever are you using bootstrap? Use your time to properly learn html and css. Bootstrap and other "systems" are of false benefit, and simply add a layer of confusion and code bloat.
If, after you really know and grok html and css, you want to try those bits of silliness, then give them a look. At this apparent stage of your learning curve, you aren't in a position to judge the real value (none) and real usefulness (also none). Bootstrap et al are actually steps backward, remixing structure and presentation and damaging the document's accessibility.
And now, your question:
The element belongs to the two separate classes. See http://www.w3.org/TR/REC-html40/struct/global.html#h-7.5.2
In the html5 specs, there is this:
§1.7.1 How to read this specification
This specification should be read like all other specifications. First, it should be read cover-to-cover, multiple times. Then, it should be read backwards at least once. Then it should be read by picking random sections from the contents list and following all the cross-references.
Sorry gary and thanks for your advice
Gary what you said is really true , i totally agree , CSS and HTML is not easy , and even if you know enough and everything , it still takes even longer to implement your knowledge at a project level and that simple because its so much difficult to predict the CSS behaviors , the only reason , i took up bootstrap is because i need to build a project , and i can't do that from ground up , i am familier with bootstrap , i have used it for a while , but since my CSS knowledge is not so great , i try and read books and stuff that will really start from the basic . well , i know this is not the best approach but its just that i have to complete this project . And yes gary , I will focus more on the core CSS than frameworks
Thank you once again .
Kind regards .