Prototype landing page cards

Personal notes about application and web development.
iOS

iOS, Swift, and Xcode course notes.
Asciidoctor

Formatting tips, doc links, and techniques.
Antora

Antora techniques and doc links.
Module 4

Empty notebook.
Module 5

Empty notebook.
Module 6

Empty notebook.
Source Code

To try this technique, copy the code below into an AsciiDoc file. Then insert your choice of URL. This technique was adapted from https://benmarshall.me/responsive-iframes/.
Copy this code into your AsciiDoc file:
++++
<br>
  <!-- <div class="container"> -->
    <div class="card-deck">
        <div class="card" onclick="location.href='../ios/ios-doc-links.html';" style="cursor: pointer;">
            <!-- <img class="card-img-top img-fluid" src="../../site-home/latest/_images/web-design.png" alt="Card image cap"> -->
              <div class="card-body">
                  <h3 class="card-title">iOS</h3>
                  <hr>
                  <p class="card-text">iOS, Swift, and Xcode course notes.</p>
              </div>
        </div>

        <div class="card" onclick="location.href='../asciidoctor/asciidoctor-doc-links.html';" style="cursor: pointer;">
            <!-- <img class="card-img-top img-fluid" src="../../site-home/latest/_images/sustainable-living.png" alt="Card image cap"> -->
            <div class="card-body">
                <h3 class="card-title">Asciidoctor</h3>
                <hr>
                <p class="card-text">Formatting tips, doc links, and techniques.</p>
                <!-- <p class="card-text"><small class="text-muted">Last updated 3 mins ago</small></p> -->
            </div>
        </div>
        <div class="card" onclick="location.href='../jamstack/antora-doc-links.html';" style="cursor: pointer;">
            <!-- <img class="card-img-top img-fluid" src="../../site-home/latest/_images/green-hands.png" alt="Card image cap"> -->
            <div class="card-body">
                <h3 class="card-title">Antora</h3>
                <hr>
                <p class="card-text">Antora techniques and doc links.</p>
            </div>
        </div>
    </div>
    <br>
    <div class="card-deck">
        <div class="card" onclick="location.href='../module4/about-module4.html';" style="cursor: pointer;">
            <div class="card-body">
                <h3 class="card-title">Module 4</h3>
                <hr>
                <p class="card-text">Empty notebook.</p>
            </div>
        </div>
          <div class="card" onclick="location.href='../module5/about-module5.html';" style="cursor: pointer;">
            <div class="card-body">
                <h3 class="card-title">Module 5</h3>
                <hr>
                <p class="card-text">Empty notebook.</p>
            </div>
        </div>
      <div class="card" onclick="location.href='../module6/about-module6.html';" style="cursor: pointer;">
            <div class="card-body">
                <h3 class="card-title">Module 6</h3>
                <hr>
                <p class="card-text">Empty notebook.</p>
            </div>
        </div>
    </div>
<!-- </div> -->

<style>
.container {
  width: 100%;
  padding-right: 15px;
  padding-left: 15px;
  margin-right: auto;
  margin-left: auto;
}

@media (min-width: 576px) {
  .container {
    max-width: 540px;
  }
}

@media (min-width: 768px) {
  .container {
    max-width: 720px;
  }
}

@media (min-width: 992px) {
  .container {
    max-width: 960px;
  }
}

@media (min-width: 1200px) {
  .container {
    max-width: 1140px;
  }
}

.container-fluid {
  width: 100%;
  padding-right: 15px;
  padding-left: 15px;
  margin-right: auto;
  margin-left: auto;
}

.card {
  position: relative;
  display: -ms-flexbox;
  display: flex;
  -ms-flex-direction: column;
  flex-direction: column;
  min-width: 0;
  word-wrap: break-word;
  background-color: #fff;
  background-clip: border-box;
  border: 1px solid rgba(0, 0, 0, 0.125);
  border-radius: 0.25rem;
  /* Special styling for 2nd level landing page cards */
  box-shadow: 0 4px 8px 0 rgba(0, 0, 0, 0.2); /* this adds the "card" effect */
  padding: 16px;
  text-align: left;
  background-color: #f1f1f1;
}

.card > hr {
  margin-right: 0;
  margin-left: 0;
}

.card > .list-group:first-child .list-group-item:first-child {
  border-top-left-radius: 0.25rem;
  border-top-right-radius: 0.25rem;
}

.card > .list-group:last-child .list-group-item:last-child {
  border-bottom-right-radius: 0.25rem;
  border-bottom-left-radius: 0.25rem;
}

.card-body {
  -ms-flex: 1 1 auto;
  flex: 1 1 auto;
  padding: 1.25rem;
}

.card-title {
  margin-bottom: 0.75rem;
  text-align: center;
  padding-bottom: 15px;
}

.h3 {
  margin-bottom: 0.75rem;
}

.card-subtitle {
  margin-top: -0.375rem;
  margin-bottom: 0;
}

.card-text:last-child {
  margin-bottom: 0;
}

.card-link:hover {
  text-decoration: none;
}

.card-link + .card-link {
  margin-left: 1.25rem;
}

.card-header {
  padding: 0.75rem 1.25rem;
  margin-bottom: 0;
  background-color: rgba(0, 0, 0, 0.03);
  border-bottom: 1px solid rgba(0, 0, 0, 0.125);
}

.card-header:first-child {
  border-radius: calc(0.25rem - 1px) calc(0.25rem - 1px) 0 0;
}

.card-header + .list-group .list-group-item:first-child {
  border-top: 0;
}

.card-footer {
  padding: 0.75rem 1.25rem;
  background-color: rgba(0, 0, 0, 0.03);
  border-top: 1px solid rgba(0, 0, 0, 0.125);
}

.card-footer:last-child {
  border-radius: 0 0 calc(0.25rem - 1px) calc(0.25rem - 1px);
}

.card-header-tabs {
  margin-right: -0.625rem;
  margin-bottom: -0.75rem;
  margin-left: -0.625rem;
  border-bottom: 0;
}

.card-header-pills {
  margin-right: -0.625rem;
  margin-left: -0.625rem;
}

.card-img-overlay {
  position: absolute;
  top: 0;
  right: 0;
  bottom: 0;
  left: 0;
  padding: 1.25rem;
}

.card-img {
  width: 100%;
  border-radius: calc(0.25rem - 1px);
}

.card-img-top {
  width: 100%;
  border-top-left-radius: calc(0.25rem - 1px);
  border-top-right-radius: calc(0.25rem - 1px);
}

.card-img-bottom {
  width: 100%;
  border-bottom-right-radius: calc(0.25rem - 1px);
  border-bottom-left-radius: calc(0.25rem - 1px);
}

.card-deck {
  display: -ms-flexbox;
  display: flex;
  -ms-flex-direction: column;
  flex-direction: column;
}

.card-deck .card {
  margin-bottom: 15px;
}

@media (min-width: 576px) {
  .card-deck {
    -ms-flex-flow: row wrap;
    flex-flow: row wrap;
    margin-right: -15px;
    margin-left: -15px;
  }
  .card-deck .card {
    display: -ms-flexbox;
    display: flex;
    -ms-flex: 1 0 0%;
    flex: 1 0 0%;
    -ms-flex-direction: column;
    flex-direction: column;
    margin-right: 15px;
    margin-bottom: 0;
    margin-left: 15px;
  }
}

.card-group {
  display: -ms-flexbox;
  display: flex;
  -ms-flex-direction: column;
  flex-direction: column;
}

.card-group > .card {
  margin-bottom: 15px;
}

@media (min-width: 576px) {
  .card-group {
    -ms-flex-flow: row wrap;
    flex-flow: row wrap;
  }
  .card-group > .card {
    -ms-flex: 1 0 0%;
    flex: 1 0 0%;
    margin-bottom: 0;
  }
  .card-group > .card + .card {
    margin-left: 0;
    border-left: 0;
  }
  .card-group > .card:first-child {
    border-top-right-radius: 0;
    border-bottom-right-radius: 0;
  }
  .card-group > .card:first-child .card-img-top,
  .card-group > .card:first-child .card-header {
    border-top-right-radius: 0;
  }
  .card-group > .card:first-child .card-img-bottom,
  .card-group > .card:first-child .card-footer {
    border-bottom-right-radius: 0;
  }
  .card-group > .card:last-child {
    border-top-left-radius: 0;
    border-bottom-left-radius: 0;
  }
  .card-group > .card:last-child .card-img-top,
  .card-group > .card:last-child .card-header {
    border-top-left-radius: 0;
  }
  .card-group > .card:last-child .card-img-bottom,
  .card-group > .card:last-child .card-footer {
    border-bottom-left-radius: 0;
  }
  .card-group > .card:only-child {
    border-radius: 0.25rem;
  }
  .card-group > .card:only-child .card-img-top,
  .card-group > .card:only-child .card-header {
    border-top-left-radius: 0.25rem;
    border-top-right-radius: 0.25rem;
  }
  .card-group > .card:only-child .card-img-bottom,
  .card-group > .card:only-child .card-footer {
    border-bottom-right-radius: 0.25rem;
    border-bottom-left-radius: 0.25rem;
  }
  .card-group > .card:not(:first-child):not(:last-child):not(:only-child) {
    border-radius: 0;
  }
  .card-group > .card:not(:first-child):not(:last-child):not(:only-child) .card-img-top,
  .card-group > .card:not(:first-child):not(:last-child):not(:only-child) .card-img-bottom,
  .card-group > .card:not(:first-child):not(:last-child):not(:only-child) .card-header,
  .card-group > .card:not(:first-child):not(:last-child):not(:only-child) .card-footer {
    border-radius: 0;
  }
}

.card-columns .card {
  margin-bottom: 0.75rem;
}

@media (min-width: 576px) {
  .card-columns {
    -webkit-column-count: 3;
    -moz-column-count: 3;
    column-count: 3;
    -webkit-column-gap: 1.25rem;
    -moz-column-gap: 1.25rem;
    column-gap: 1.25rem;
    orphans: 1;
    widows: 1;
  }
  .card-columns .card {
    display: inline-block;
    width: 100%;
  }
}

.accordion .card:not(:first-of-type):not(:last-of-type) {
  border-bottom: 0;
  border-radius: 0;
}

.accordion .card:not(:first-of-type) .card-header:first-child {
  border-radius: 0;
}

.accordion .card:first-of-type {
  border-bottom: 0;
  border-bottom-right-radius: 0;
  border-bottom-left-radius: 0;
}

.accordion .card:last-of-type {
  border-top-left-radius: 0;
  border-top-right-radius: 0;
}
}
</style>
++++