Yes, you can specify fractional pixels. As this has been part of CSS since the very first version, it should be well supported by any browser that supports CSS at all.

Reference: [CSS 2.1: 4.3.2 Lengths][1]

&gt; &quot;The format of a length value (denoted by &amp;lt;length&amp;gt; in this
&gt; specification) is a &amp;lt;number&amp;gt; (with or without a decimal point)
&gt; immediately followed by a unit identifier (e.g., px, em, etc.).&quot;

When the elements are displayed on the screen, most browsers will naturally round the position to the nearest pixel when using 100% zoom level. On higher zoom levels you will notice that fractional pixel values are recognized.


  [1]: http://www.w3.org/TR/2011/REC-CSS2-20110607/syndata.html#length-units

Scala&#39;s `MapLike` trait has a method

    mapValues [C] (f: (B) ⇒ C): Map[A, C] 

But I sometimes want a different type:

    mapKeysAndValues [C] (f: (A, B) ⇒ C): Map[A, C] 

Is there a simple way to do this which I am missing? Of course, this can be done with a fold.

Map both keys and values of a Scala Map

Since I&#39;ve known about Node.js, I&#39;ve always been a fan of it. But today I found about [SignalR][1], which provides an alternative asynchronous - scalable - realtime model for ASP.NET. 

As far as I know, the main advantage of Node.js over SignalR is sharing code between client-server (another advantage should be that it is cross-platform), and the main advantage of SignalR is a much more mature framework and far better tool (IDE) support. So I wonder: if SignalR is here, do we need Node.js on Windows anymore? Are there any advantages of Node.js I don&#39;t know?


  [1]: https://github.com/SignalR/SignalR

Nodejs vs SignalR: why do we need server-side javascript?

Can a CSS `px` be a fraction? Is it allowed by the standards? And if so, do the major browsers support it?

Let&#39;s back the answers up with documentation, folks.

Can a CSS pixel be a fraction?

<p>Can a CSS <code>px</code> be a fraction? Is it allowed by the standards? And if so, do the major browsers support it?</p>
<p>Let's back the answers up with documentation, folks.</p>


Here is the story: I&#39;m using SWFObject to insert a Flash object into my page. The embedding eats my `span`. So, I lose all my CSS for it. I was thinking of moving all of the CSS to the parent so I don&#39;t lose my CSS styles when the Flash appears. 

I have tried using a `span` within a `span`, but I don&#39;t think it&#39;s working. Is there a reason for this? I don&#39;t understand why you could have `div` within a `div` but not a `span` within a `span`.

Does it have to do with `spans` being inline?

Can you have a &lt;span&gt; within a &lt;span&gt;?

I want to be able to draw a border OUTSIDE of my Div! So if my div is say 20px by 20px, I want a 1px border outside of this (so in essence, I get a div 22x22px large). 

I understand that I can just make the div 22x22 to start with, but for reasons I have, I need the borders to be on the outside.

CSS outline works, but I want only border-bottom or border-top thingy, so something like outline-bottom, which does not work, is what I want.

Is there a way to do this?

Thanks

CSS Outside Border

I would like to write a CSS selector rule that selects all elements that _don&#39;t_ have a certain class. For example, given the following HTML:

    &lt;html class=&quot;printable&quot;&gt;
        &lt;body class=&quot;printable&quot;&gt;
            &lt;h1 class=&quot;printable&quot;&gt;Example&lt;/h1&gt;
            &lt;nav&gt;
                &lt;!-- Some menu links... --&gt;
            &lt;/nav&gt;
            &lt;a href=&quot;javascript:void(0)&quot; onclick=&quot;javascript:self.print()&quot;&gt;Print me!&lt;/a&gt;
            &lt;p class=&quot;printable&quot;&gt;
                This page is super interresting and you should print it!
            &lt;/p&gt;
        &lt;/body&gt;
    &lt;/html&gt;

I would like to write a selector that selects all elements that don&#39;t have the &quot;printable&quot; class which, in this case, are the _nav_ and _a_ elements.

Is this possible?

NOTE: in the actual HTML where I would like to use this, there are going to be a lot more elements that _don&#39;t_ have the &quot;printable&quot; class than do (I realize it&#39;s the other way around in the above example).

Can I write a CSS selector selecting elements NOT having a certain class or attribute?

Imagine I have the following CSS

    font-family: &#39;Non-existant Sans&#39;, Arial, sans-serif;

Assuming &#39;Non-existant Sans&#39; is not installed on the system, Arial will be used by the browser. Using Chrome, is there any way of finding out which font is being rendered?

**Edit:** Dave (in the comments to the question) has pointed out a similar question. I&#39;m specifically asking about Chrome here. Many of the answers in the other question suggest extensions which are okay, however; is there a native way of determining this information using the Dev Tools alone?

**Edit Sept 2013:** The Chrome team have just announced that font-family inspection is now available in the [latest builds of Chrome Canary][1] (Twitter link contains an image with more info). This should trickle down through dev &gt; beta &gt; stable over the next few weeks – great news!

[1]: https://twitter.com/chromiumdev/status/384098351353839616

How do I tell which font Chrome is using?

So, I have an `app/assets/stylesheets/` directory structure that looks something like this:

       |-dialogs
       |-mixins
       |---buttons
       |---gradients
       |---vendor_support
       |---widgets
       |-pages
       |-structure
       |-ui_elements

In each directory, there are multiple sass partials (usually *.css.scss, but one or two *.css.scss.erb).

I might be assuming a lot, but rails SHOULD automatically compile all the files in those directories because of `*= require_tree .` in application.css, right?

I recently have tried restructuring these files by removing all color variables and placing them in a file in the root `app/assets/stylesheets` folder (_colors.css.scss). I then created a file in the root `app/assets/stylesheets` folder called master.css.scss which looks like this:

    // Color Palette 
    @import &quot;colors&quot;;
    
    // Mixins
    @import &quot;mixins/buttons/standard_button&quot;;
    @import &quot;mixins/gradients/table_header_fade&quot;;
    @import &quot;mixins/vendor_support/rounded_corners&quot;;
    @import &quot;mixins/vendor_support/rounded_corners_top&quot;;
    @import &quot;mixins/vendor_support/box_shadow&quot;;
    @import &quot;mixins/vendor_support/opacity&quot;;

I don&#39;t really understand how rails handles the order of asset compilation, but it&#39;s obviously not in my favor. It appears none of the files realize they have any variables or mixins being imported, and so it throws errors and I can&#39;t compile. 

    Undefined variable: &quot;$dialog_divider_color&quot;.
      (in /home/blah/app/assets/stylesheets/dialogs/dialog.css.scss.erb)

    Undefined mixin &#39;rounded_corners&#39;.
      (in /home/blah/app/assets/stylesheets/widgets.css.scss)

The variable `$dialog_divider_color` is clearly defined in _colors.css.scss, and `_master.css.scss` is importing colors and all my mixins. But apparently rails didn&#39;t get that memo.

Is there some way I can fix these errors, or will I need to resort to putting all my variable definitions back into each individual file, as well as all the mixin imports?

Unfortunately, [this guy][1] doesn&#39;t seem to think it&#39;s possible, but I&#39;m hoping he&#39;s wrong. Any thoughts are greatly appreciated.


  [1]: https://stackoverflow.com/questions/8887824/persisting-scss-variables-in-rails-asset-pipeline

Proper SCSS Asset Structure in Rails

Why don&#39;t we have `box-sizing: margin-box;`? Usually when we put `box-sizing: border-box;` in our style sheets we really mean the former.

&lt;br&gt;
**Example:**

Let&#39;s say I have a 2 column page layout. Both columns have a width of 50%, but they look kind of ugly because there&#39;s no gutter (gap in the middle); Below is the CSS:

	.col2 {
		width: 50%;
		float: left;
	}



&lt;br&gt;To apply a gutter you might think we could just set a right margin on the first of the 2 columns; something like this:

	.col2:first-child {
		margin-right: 24px;
	}

But this would make the second column wrap onto a new line, because the following is true:

	50% + 50% + 24px &gt; 100%

`box-sizing: margin-box;` would solve this issue by including margin in the calculated width of the element. I would find this *very* useful if not more useful than `box-sizing: border-box;`.

CSS3 box-sizing: margin-box; Why not?

I wish HTML could do something semantically equivalent to this;

    &lt;dl class=&quot;main-list&quot;&gt;
        &lt;definitionitem&gt;
            &lt;dt&gt;Some Thing&lt;/dt&gt;
                &lt;dd&gt;You know it!&lt;/dd&gt;
            &lt;dt&gt;Another Thing&lt;/dt&gt;
                &lt;dd&gt;Word.&lt;/dd&gt;
        &lt;/definitionitem&gt;
        &lt;definitionitem&gt;
            &lt;dt&gt;Stuff&lt;/dt&gt;
                &lt;dd&gt;Alright!&lt;/dd&gt;
        &lt;/definitionitem&gt;
    &lt;/dl&gt;

However, since the closest I&#39;ve come is something I&#39;m not 100% satisfied with the semantics of;

    &lt;div class=&quot;redundant-wrapper&quot;&gt;
        &lt;dl class=&quot;main-list&quot;&gt;
            &lt;dt&gt;Some Thing&lt;/dt&gt;
                &lt;dd&gt;You know it!&lt;/dd&gt;
            &lt;dt&gt;Another Thing&lt;/dt&gt;
                &lt;dd&gt;Word.&lt;/dd&gt;
        &lt;/dl&gt;
        &lt;dl class=&quot;another-main-list&quot;&gt;
            &lt;dt&gt;Stuff!&lt;/dt&gt;
                &lt;dd&gt;Alright!&lt;/dd&gt;
        &lt;/dl&gt;
    &lt;/div&gt;

I was wondering if anyone has any other ideas of how you might do this?

Also, the reason the items would be grouped is because they are visually grouped in the content that is being marked up. Imagine a dictionary page, with a single definition list, where each definition is in an inset box that is floated left. I run into this situation all the time.

Is there a valid way to wrap a dt and a dd with an HTML element?

If you look at the [CSS box model spec][1], you&#39;ll observe the following:

&gt; The [margin] percentage is calculated with respect to the **width** of the generated box&#39;s containing block. **Note that this is true for &#39;margin-top&#39; and &#39;margin-bottom&#39; as well.** If the containing block&#39;s width depends on this element, then the resulting layout is undefined in CSS 2.1.  *(emphasis mine)*


  [1]: http://www.w3.org/TR/CSS2/box.html#margin-properties

This is indeed true.   But *why*?  What on earth would compel anyone to design it this way?  It&#39;s easy to think of scenarios where you want, e.g. a certain thing to always be 25% down from the top of the page, but it&#39;s hard to come up with any reason why you would want vertical padding to be relative to the horizontal size of the parent.

Here&#39;s an example of the phenomenon I&#39;m referring to:

    &lt;div style=&quot;border: 1px solid red; margin: 0; padding: 0; width: 200px; height: 800px;&quot;&gt;
      This div is 200x800.
      &lt;div style=&quot;border: 1px solid blue; margin: 10% 0 0 10%;&quot;&gt;
        This div has top-margin of 10% and left-margin of 10% with respect to its parent.
      &lt;/div&gt;
    &lt;/div&gt;
http://jsfiddle.net/8JDYD/

Why are margin/padding percentages in CSS always calculated against width?

Let&#39;s say I have the SVG file:

    &lt;svg width=&quot;1024&quot; height=&quot;768&quot; xmlns=&quot;http://www.w3.org/2000/svg&quot; xmlns:xlink=&quot;http://www.w3.org/1999/xlink&quot;&gt;
    	&lt;text x=&#39;20&#39; y=&#39;60&#39; style=&quot;font-size: 60px&quot;&gt;b&lt;/text&gt;
    	&lt;text x=&#39;100&#39; y=&#39;60&#39; style=&quot;font-size: 60px&quot;&gt;a&lt;/text&gt;
    &lt;/svg&gt;

I want to somehow align the top of `a` and `b`. Actually, I want my positioning to be according to the `roofline` instead of `baseline`!

vertical alignment of text element in SVG

In HTML5 we currently have a `&lt;figure&gt;` element, defined like so ([W3C reference][1]) 

&gt; The figure element represents a unit of content, optionally with a caption, that is self-contained, that is typically referenced as a single unit from the main flow of the document, and that can be moved away from the main flow of the document without affecting the document’s meaning.


Recently a new element `&lt;picture&gt;` was proposed by the [Responsive Images Community group][2] and it was defined [in the reference][3] like so

&gt; The picture element used for displaying an image that can come from a range of sources (see srcset attribute). Which image the user agent displays depends on the algorithm for deriving the source image. 

Since the two descriptions seems to be not contradictory (and documentation on picture is on *draft* state yet) here my question: is it possible (technically and semantically) to have a nested `picture` inside a `figure` element, in this way?

    &lt;figure&gt;
       &lt;picture&gt;
          &lt;source ...&gt;
          &lt;source ...&gt;
          &lt;source ...&gt;
          &lt;img..&gt;
       &lt;/picture&gt;
    
       &lt;figcaption&gt;...&lt;/figcaption&gt;
    &lt;/figure&gt;

I&#39;ve found no references about it in specs. :\

Note: I&#39;m aware that no browser implements currently this element, I&#39;m just making some experiments with [jQuery picture][4]  

Thank you.


  [1]: http://dev.w3.org/html5/markup/figure.html
  [2]: http://www.w3.org/community/respimg/
  [3]: http://dvcs.w3.org/hg/html-proposals/raw-file/tip/responsive-images/responsive-images.html#the-picture-element
  [4]: http://jquerypicture.com/

Content Type	Original Author	Original Content on Stackoverflow
Question	Kees C. Bakker	View Question on Stackoverflow
Solution 1 - Css	Guffa	View Answer on Stackoverflow

Can a CSS pixel be a fraction?

Css Problem Overview

Css Solutions

Solution 1 - Css

Nodejs vs SignalR: why do we need server-side javascript?

Map both keys and values of a Scala Map

Attributions