Pure CSS Photo Gallery with Image Lightbox Support

Preview:

Description:

A pure CSS/CSS3 based responsive photo gallery for your portfolio website that has the ability to view the large image version in a lightbox.

How to use it:

Insert your small images as thumbnails into a grid as follows.

<div class="grid">
  <label for="pic-1" class="grid-item"><img src="1.jpg"></label>
  <label for="pic-2" class="grid-item"><img src="2.jpg"></label>
  <label for="pic-3" class="grid-item"><img src="3.jpg"></label>
  <label for="pic-4" class="grid-item"><img src="4.jpg"></label>
  <label for="pic-5" class="grid-item"><img src="5.jpg"></label>
  ...
</div>

Insert the large images which will display in a responsive fullscreen lightbox.

<input type="checkbox" id="pic-1">
<label for="pic-1" class="lightbox"><img src="large-1.jpg"></label>
<input type="checkbox" id="pic-2">
<label for="pic-2" class="lightbox"><img src="large-2.jpg"></label>
<input type="checkbox" id="pic-3">
<label for="pic-3" class="lightbox"><img src="large-3.jpg"></label>
<input type="checkbox" id="pic-4">
<label for="pic-4" class="lightbox"><img src="large-4.jpg"></label>
<input type="checkbox" id="pic-5">
<label for="pic-5" class="lightbox"><img src="large-5.jpg"></label>

The core CSS styles for the photo gallery.

* {
  -moz-box-sizing: border-box;
  box-sizing: border-box;
}
label[for] { cursor: pointer; }
.grid {
  width: 100%;
  position: fixed;
  top: 0;
  left: 0;
  height: 100%;
  background-color: #222;
  z-index: 0;
  display: -webkit-flex;
  display: -ms-flexbox;
  display: flex;
  -webkit-flex-wrap: wrap;
  -ms-flex-wrap: wrap;
  flex-wrap: wrap;
  -webkit-align-items: flex-start;
  -ms-flex-align: start;
  align-items: flex-start;
  -webkit-align-content: flex-start;
  -ms-flex-line-pack: start;
  align-content: flex-start;
  padding: 16px;
  overflow: auto;
  text-align: center;
  -webkit-transition: opacity .75s;
  transition: opacity .75s;
}
.grid .grid-item {
  width: 25%;
  display: inline-block;
  padding: 16px;
  opacity: .75;
  -webkit-transition: opacity .5s;
  transition: opacity .5s;
}
.grid .grid-item:hover { opacity: 1; }
@media screen and (max-width: 1024px) {
.grid .grid-item { width: 50%; }
}
@media screen and (max-width: 480px) {
.grid .grid-item { width: 100%; }
}
.grid img {
  max-width: 100%;
  max-height: 100%;
  box-shadow: 0 2px 8px rgba(0, 0, 0, 0.25);
}

The required CSS for the image lightbox.

input[type="checkbox"] { display: none; }
.lightbox {
  width: 100%;
  position: fixed;
  top: 0;
  left: 0;
  min-height: 100%;
  z-index: 1;
  overflow: auto;
  -webkit-transform: scale(0);
  -ms-transform: scale(0);
  transform: scale(0);
  -webkit-transition: -webkit-transform .75s ease-out;
  transition: transform .75s ease-out;
}
.lightbox img {
  position: fixed;
  top: 50%;
  left: 50%;
  -webkit-transform: translate(-50%, -50%);
  -ms-transform: translate(-50%, -50%);
  transform: translate(-50%, -50%);
  max-width: 96%;
  max-height: 96%;
  box-shadow: 0 2px 8px rgba(0, 0, 0, 0.25);
}
input[type="checkbox"]:checked + .lightbox {
  -webkit-transform: scale(1);
  -ms-transform: scale(1);
  transform: scale(1);
}
input[type="checkbox"]:checked ~ .grid { opacity: .125; }