How to make a horizontal gallery layout without Javascript

I wanted to put together a quick guide for the horizontally-scrolling layout I use for the galleries on this site (e.g. Europe 2022). This is definitely not the most efficient way to do this, but it works and is fairly straightforward. Please let me know if you come up with any improvements. It comes baked in to the Stretch jekyll theme, too.

I’ll split this into two parts:

Using a Jekyll template to populate a gallery
Using CSS to get the populated gallery to behave the way we want

If you’re not using Jekyll then I recommend skipping straight to the CSS section, assuming that you have a set of div tags for each image, containing another div for the caption, and an img tag for the picture itself.

Jekyll Template

We’re using a layout called photo.html, which is a liquid template that loops through the photos in the gallery, pulls out the URL, caption, and alt text. It allows you to include an intro paragraph at the start of the gallery, which scrolls the same way.

The gallery data is stored in photos.yml in the site’s _data folder. Wherever your data source is,

The whole gallery is then wrapped in a div called horizontal-gallery-wrapper. Within that div, there are two parts: the initial “meta” paragraph, and then the liquid loop to generate html tags for each image in the gallery. For each image in the gallery, we can fill out an image-wrapper div with the url, title, image caption, and alt text.

<div class="horizontal-gallery-wrapper">

  <div class="gallery-meta">
    <div>
      <h1>How to make a horizontal gallery layout without Javascript</h1>
      <p>Insert gallery blurb here...</p>
    </div>
  </div>

  
</div>

CSS Layout

Fundamentally, we have a wrapper div—which enables the horizontal scroll—containing a set of divs (or other tags) for each of the images or products or projects we want to display.

<div class="horizontal-gallery-wrapper">
  <div class="wrapper" id="img-1">
  <div class="wrapper" id="img-2">
  ...
  <div class="wrapper" id="img-N">
</div>

Firstly the main wrapper, where we set the x-axis overflow to scroll, and we force the content inside not to wrap, i.e. extend as far as needed off to the right of the page. We also add a bit of padding, include a large amount of left padding in this case so that the gallery starts to the right of the menu sidebar.

.horizontal-gallery-wrapper {
  overflow-x: scroll;
  overflow-y: hidden;
  white-space: nowrap;
  padding: 10px 0;
  padding-left: 13em;
}

For each image (including the intro paragraph) we have an image-wrapper div. The contents of the inner divs is not important, as long as they each have height: 100%. Also note that if you’re putting an <img> tag inside the div, you need to set height:100% for that element as well. We can add a bit of margin to leave a gap between each of the images; this is also where we could add rounded borders or a box shadow to each of the images, if we wanted to.

I’ve also included a gallery-meta div, which contains the intro paragraph gallery title. Otherwise, it behaves behave basically the same as the image-wrapper divs. It does need some additional formatting to constrain its size, and to allow the text to display and wrap correctly. Width and padding are flexible, but vertical-align: top and white-space: normal are required.

.image-wrapper, .gallery-meta {
  display: inline-block;
  height: 100%;
  margin: 0 4px;
}

.gallery-meta {
  width: 500px;
  vertical-align: top;
  white-space: normal;
  padding: 4rem;
}

If we want to include a caption for each image (which we did in the HTML in section 1), we will need to format that too. The below css rules hide the caption by default, revealing it whenever the image itself is hovered over. In this arrangement, captions will always appear in the bottom left of the screen, and aren’t tied to the location of the associated image. If you want them to move with the image, you can add position: relative to their parent element, in this case the <a> tag actually linking to the image.

.image-caption {
  position: absolute;
  left: 2em;
  bottom: 1.5em;
  display: none;

  backdrop-filter: blur(5px);
  color: #fff;
  background: rgba(0, 0, 0, 0.5);
  border-radius: 3px;
  padding: 0.3em;
}

.image-wrapper:hover .image-caption {
  display: block;
}

Narrow Screens

For narrow screen widths or vertically oriented screens, obviously the horizontal scroll doesn’t make sense. In those circumstances I just revert horizontal-gallery-wrapper to a column-direction flex box.

@media screen and (max-width: 1000px)
.horizontal-gallery-wrapper {
  display: flex;
  flex-direction: column;
  align-items: center;
  row-gap: 1em;
}

Optional Javascript

Last section, to be written up. Basically just allows for key presses to navigate through the gallery.

Wrapping Up

That’s all there is to it! No JS required, just forcing the page contents to extend off to the right and telling the page to scroll in that direction. This effect works well with a static sidebar, where the photos can scroll under the sidebar and off the screen to the left.

Other finishing touches could include: adding a page footer into the gallery-meta div, and including a liquid content tag in that same div to allow for a custom blurb for each gallery.

See some live examples here, or at the PHOTOS link in the navbar up top.