The Perfect Button
The Lifecycle of Styling a Button
Your design calls for a button. The copy will always be short, they say. Just a single word or two, they say. And maybe it is. But then you translate it and it definitely isn’t.
And then there’s a variation with a border. So you add one, but then the alignment of the one with the border is off from the one without. And you need a big one, a little one, and another like a link.
Defeated, you reach for a library or a framework that has buttons included.
Next time, steal this code I’m about to give you for free instead.
Let’s break down exactly what our perfect button is going to need to do.
- Allow vertically centered copy
- Potentially wrap multiple lines with normal line-height
- Variant with a border
- Variant as a link
- Consistent height between variations
- Animated hover/focus states
I won’t touch on all of the CSS directly used for this button, but there are a few key players worth calling out on this Dream Team of a ruleset.
box-sizing: border-box;: When working with designers this is helpful in maintaining a consistent design language. Designers will expect a button to be a certain height that matches their design. This allows padding and border thickness to get wrapped up into a single value.
min-height: This is the minimum height of the button, which matches what our design has exactly.
display: inline-flex;: When setting a link to be a button and specifying a height and width greater than the size of the text, we need to center the text horizontally and vertically. Without this, the text is aligned in the top left corner.
border: The secret to having a consistent height between a normal and an outlined button variant is to always have a border. This enables us to side-step math and tedious to update styles later. When we don’t want a border to display, we can just set
border-color: transparent;and maintain the spacing of it.
We’re using CSS Custom Properties to keep the button variations maintainable. Using different classes for the variations enables us to have a single location to update our CSS variables for all of the different button states, like
:focus, as well as link states for when our button is actually a hyperlink, like
With CSS Variables, we’re able to declare our default values in our main ruleset for our button. By adding rulesets for the different variations and overriding the variables, we can leverage the
var() declarations inside rulesets that are lower in the Cascade. This works because Custom Properties in
var() resolve at computed-value time.
Without CSS Variables, we’d have to create additional selectors for each of these states and set their values. These immediately makes our CSS more challenging to follow and to maintain.
It’s worth mentioning a potential downside about CSS Custom Properties: They don’t work in Internet Explorer.
The good news is that all of the other CSS has good browser support, if you actually want to use this button. You can get more familiar with the code by refactoring to support legacy browsers. You can add vendor prefixes on the flexbox properties to support down to IE10.