outline is your friend

If you open a plain HTML document with no CSS and you focus an interactive element like a button, link, or textarea, you’ll see that by default browsers use the outline property to highlight these elements.

A blue outline around a focused b…


This content originally appeared on Web development blog - Manuel Matuzović and was authored by Manuel Matuzović

If you open a plain HTML document with no CSS and you focus an interactive element like a button, link, or textarea, you’ll see that by default browsers use the outline property to highlight these elements.

A simple demo of a link a button and a textarea

A blue outline around a focused button in Firefox

outline is great

The outline property is the perfect candidate for this job for several reasons.

  • outline doesn’t break layout.

    Unlike the border property (if box-sizing is not set to border-box), outline doesn’t add to the width and height of an element. It just creates an outline without taking up any space.

  • You can add spacing between the content and the outline using outline-offset.
    A focused link in a paragraph
    Outlines on Stephanie Eckles website have some extra spacing.

  • You can customize the width, style, and color.

    A random teaser of a blog post.
    Big, red, dotted outline around a link in a teaser on smashingmagazine.com
    :focus {
      outline-width: 3px;
      outline-style: dotted;
      outline-color: #d33a2c;
      outline-offset: 2px;
    }

  • outline works great in forced color modes like Windows High Contrast Mode (WHCM)

    Dark background color, white text and blueish highlights instead of white background, black text color and red highlights.
    The same outline with different colors in a dark Windows theme.

outline sucks

There are also disadvantages to using outline.

  • Outlines don’t look nice.

    Yes, outlines don’t necessarily look great, but 1. Oh my god, who cares? It doesn’t have to look nice, it just has to work well for your users and 2. you can tweak them to a certain degree and make them work with your design (see smashingmagazine.com).

  • The default outline might not be visible enough.

    I advice against leaving the default focus styles untouched because they might not work with every design. Overwrite them with something that works better with your theme.

    /* Removes the default outline only in browsers that support :focus-visible */
    :focus:not(:focus-visible) {
      outline: none;
    }

    :focus-visible {
      outline: 2px dashed #282828;
      outline-offset: 2px;
    }
    A clearly visible, 2px dashed outline around a button.

What about other properties?

If you remember, one of the advantages of outline is that it works great in forced color mode. If this property works well, it means that there must be properties that don’t work well.

Here’s an example. Instead of using outline, I change the background and add a box-shadow on focus-visible.

:focus:not(:focus-visible) {
  outline: none;
}

:focus-visible {
  outline: none;
  background: #000;
  color: #fff;
  box-shadow: 0 2px 0 0 #fff, 0 5px 0 0 #000;
}

This is how focus styles on the button look like with regular contrast settings.

Dark background color on the button and a thick dark line below

And here’s the same focused button in WHCM. We don’t see anything because these properties are reverted in forced color modes.

The styling of the button didn’t change at all

Transparent outlines

Now you might be thinking “But…but a11yproject.com and gov.uk are using background colors for some of their focus styles”. Yes, they are using background-color, but they’re doing it in combination with outline. This is a nice trick to avoid visible outlines in normal color mode and assure that they’re displayed in forced color mode.

.c-homepage-card__cta:focus {
  background-color: #fb37ff;
  color: #000;
  outline: 3px solid #fb37ff;
}
pink background on focused links.

a11yproject.com uses the same color for the outline as for the background.

just an outline on focused links.
No background color in WHCM. 
.govuk-link:focus {
  outline: 3px solid transparent;
  color: #0b0c0c;
  background-color: #fd0;
  box-shadow: 0 -2px #fd0,0 4px #0b0c0c;
  text-decoration: none;
}
yellow background an think black underline on focused links

gov.uk uses a background color and box-shadow in combination with a transparent outline

just an outline on focused links.

No background color and box shadow in WHCM.

Conclusion

Be careful when customizing focus styles, don’t forget to test in forced color modes, and always remember that outline is your friend.


This content originally appeared on Web development blog - Manuel Matuzović and was authored by Manuel Matuzović


Print Share Comment Cite Upload Translate Updates
APA

Manuel Matuzović | Sciencx (2022-08-17T09:38:54+00:00) outline is your friend. Retrieved from https://www.scien.cx/2022/08/17/outline-is-your-friend/

MLA
" » outline is your friend." Manuel Matuzović | Sciencx - Wednesday August 17, 2022, https://www.scien.cx/2022/08/17/outline-is-your-friend/
HARVARD
Manuel Matuzović | Sciencx Wednesday August 17, 2022 » outline is your friend., viewed ,<https://www.scien.cx/2022/08/17/outline-is-your-friend/>
VANCOUVER
Manuel Matuzović | Sciencx - » outline is your friend. [Internet]. [Accessed ]. Available from: https://www.scien.cx/2022/08/17/outline-is-your-friend/
CHICAGO
" » outline is your friend." Manuel Matuzović | Sciencx - Accessed . https://www.scien.cx/2022/08/17/outline-is-your-friend/
IEEE
" » outline is your friend." Manuel Matuzović | Sciencx [Online]. Available: https://www.scien.cx/2022/08/17/outline-is-your-friend/. [Accessed: ]
rf:citation
» outline is your friend | Manuel Matuzović | Sciencx | https://www.scien.cx/2022/08/17/outline-is-your-friend/ |

Please log in to upload a file.



There are no updates yet.
Click the Upload button above to add an update.

You must be logged in to translate posts. Please log in or register.

Related Posts