Recently I have been dedicating some time to the study of the fundamentals of HTML and CSS. A couple of days ago I wrote a blog post on my very first Front-End Kata. The result is this Slack-like card:

The link to the CodePen: Slack Card

I decided to write a couple of follow up articles to share a few things I learned through this experience. It isn't mean to teach the basics of CSS, just meant to share 2 or 3 interesting pieces of info I remembered the most 🙂. Today is the first one of the series.

Background Image With Rounded Corners

The HTML code for the Slack card looks like this:

<div class="slack-card">
  <div class="header-with-img">
    …Picture and Name...
  </div>
  <div class="time-and-date">
    ...
  </div>
  <ul class="profile-actions">
    ...
  </ul>
</div>

The Profile Picture is a background-image set in .header-with-img, but the rounded corners were set on the parent .slack-card with border-radius. What would happen is that while the .slack-card would be rounded as expected, it wouldn't clip the background image of .header-with-img and the image would be visible outside the boundaries of .slack-card.

Here is a picture presenting the problem, I added transparency and exaggerated the border-radius to highlight the issue:

What's the fix? Well, another way of describing the problem would be to say the .header-with-img was overflowing from the .slack-card container. The fix to allow clipping was simply to add overflow: hidden to .slack-card:

.slack-card {
    ...
    overflow: hidden;
    ...
}

And here is the result 😃

I could see at least 2 other possibilities for solving this problem:

• Setting the same border-radius on the .header-with-img
• Removing border-radius from .slack-card altogether, and dealing with the corner rounding in .header-with-img for 2 top corners and profile-actions for the 2 bottom ones.

That being said, I wasn't a fan of the first alternative because of the redundancy it induces, and I wasn't a fan of the second one because I wasn't sure how the shadow would behave.

Either way, if you have arguments for one or the other of the alternative solutions, or maybe even a third idea, be sure to let me know in the comments or @ThisIsFlorianK on Twitter ;)

Until next time — The Professional Beginner