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Blogs about responsive

Seven Things You Should Know About Flexbox.


Flexbox is a great CSS module for making clean and flexible layouts. But flexbox is a bit odd, it can be tricky to get the results you're looking for when you're just getting started. Here are some things you should know about flexbox:

  1. display: flex; goes on a parent element. Then all children of that element become flex items and will accept other flex properties.
  2. Don't use float or box-sizing: border-box; with flex elements. It won't work they way that you'd expect from display or inline elements.
  3. flex-direction defaults to row to lay flex elements out horizontally. Sometimes, you want column to lay elements out vertically instead.
  4. margin-[side]: auto; makes the margin use up all the available space on that side. If multiple margins (in the same dimension) are auto, they each take an even share of the available space
  5. flex-grow: defaults to 0; where elements won't grow beyond the content's width. You probably want flex-grow: 1. Among other things, this handy for making all input elements stretch to use up the remaining space:
  6. flex-wrap: defaults to nowrap, where all elements will be stuffed on a single line (or a single column, for flex-direction: column;). Alternately, you may want flex-wrap: wrap; to allow the elements to flow to multiple rows.
  7. Flexbox is well-supported in all recent versions of Firefox, Chrome, Safari, Chrome, Edge, mobile browsers, and even passably-well supported in IE. See

For more about flexbox, see:

Breakpoint Backgrounds Bookmarklet.


When working with media queries, I find it useful to set a page's background color to something to indicate the breakpoint change. But it gets tedious to set it in the browser development tools over and over again, so I figured I'd just handle it with a bookmarklet - a block of JavaScript that you can execute by using a bookmark in your browser.

Since this is just a debugging tool on a local machine, even the simplest methods will get the job done. The most interesting thing is the enclosing javascript:(function(){ and })(); - just javascript protocol which tells the browser to execute it, and wee little anonymous function to hold everything together. Inside that, I create a style tag, and populate it with new media queries and declarations: set the background color to magenta for roughly mobile width browsers, teal for tablets, and orange for widescreen. (I couldn't think of an alliterative color for "w", since I usually wanted to overrule a white background.) All of the styles have a !important to avoid worrying about specificity. Here's the whole thing:

  var css = document.createElement("style");
  css.type = "text/css";
  css.innerHTML = "@media only screen and (max-width: 800px) { body { background-color: teal !important; } }" +
    "@media only screen and (max-width: 540px) { body { background-color: magenta !important; } } " +
    "@media screen and (min-width:1300px) { body { background-color: orange !important; } }";

Just load this up inside the location field for a new bookmark, and run it whenever you want to add the colors. Feel free to change the breakpoints to something for your site. It's just CSS on the inside, so you might have to reset a few more colors or adjust the selectors for your site.

For more on bookmarklets, see Bookmarklets FTW The Case by Lydia Katsamberis from Cascadia JS 2014.