Question

I am trying to select this, using both is and class:

<div class="phase" id="1">

and nothing works, I tried:

.phase#1
#1.phase
div#1.phase

could it be the #1? I never ran into problems with a numeric id

Update:
It seems I confused jQuery selectors and CSS selectors,
this would work fine with jQuery:

$(".phase#1")

but this:

.phase#1 {}

Will not work in CSS

Answer 1

The id attribute specifies a unique id for an HTML element (the value must be unique within the HTML document).
So if you selected by id you shouldn’t also selected by class.

Specifies a unique id for the element. Naming rules:

1. Must begin with a letter A-Z or a-z
2. Can be followed by: letters
   (A-Za-z), digits (0-9), hyphens (“-“), and underscores (“_”)
3. In HTML, all values are case-insensitive

HTML id Attribute specification