<div class="card-22">
  <div class="card-22__grid"></div>
  <div class="card-22__marks">
    <div class="card-22__mark card-22__mark--tl"></div>
    <div class="card-22__mark card-22__mark--tr"></div>
    <div class="card-22__mark card-22__mark--bl"></div>
    <div class="card-22__mark card-22__mark--br"></div>
  </div>
  <div class="card-22__content">
    <span class="card-22__label">// BLUEPRINT</span>
    <h4 class="card-22__title">Blueprint</h4>
    <p class="card-22__body">Grid lines and corner marks appear on hover.</p>
  </div>
</div>

/* Demo 22 has its own title/body color transitions, so it owns those rules. */
.card-22 {
  width: 100%;
  max-width: 280px;
  position: relative;
  overflow: hidden;
  padding: 22px;
  border-radius: 14px;
  background: #17171f;
  border: 1px solid rgba(255, 255, 255, 0.08);
  cursor: pointer;
  transition:
    background 0.4s,
    border-color 0.4s,
    box-shadow 0.4s;
}
.card-22:hover {
  background: #041428;
  border-color: rgba(61, 232, 245, 0.5);
  box-shadow:
    0 0 32px rgba(61, 232, 245, 0.1),
    inset 0 0 32px rgba(61, 232, 245, 0.04);
}
.card-22__grid {
  position: absolute;
  inset: 0;
  background-image:
    linear-gradient(rgba(61, 232, 245, 0.08) 1px, transparent 1px),
    linear-gradient(90deg, rgba(61, 232, 245, 0.08) 1px, transparent 1px);
  background-size: 20px 20px;
  opacity: 0;
  transition: opacity 0.4s;
}
.card-22:hover .card-22__grid {
  opacity: 1;
}
.card-22__marks {
  position: absolute;
  inset: 0;
  z-index: 1;
}
.card-22__mark {
  position: absolute;
  width: 14px;
  height: 14px;
  opacity: 0;
  transition: opacity 0.3s 0.15s;
}
.card-22__mark::before,
.card-22__mark::after {
  content: "";
  position: absolute;
  background: rgba(61, 232, 245, 0.7);
}
.card-22__mark::before {
  width: 1px;
  height: 100%;
  left: 50%;
}
.card-22__mark::after {
  width: 100%;
  height: 1px;
  top: 50%;
}
.card-22__mark--tl { top: 10px; left: 10px; }
.card-22__mark--tr { top: 10px; right: 10px; }
.card-22__mark--bl { bottom: 10px; left: 10px; }
.card-22__mark--br { bottom: 10px; right: 10px; }
.card-22:hover .card-22__mark {
  opacity: 1;
}
.card-22__content {
  position: relative;
  z-index: 2;
}
.card-22__label {
  font-family: monospace;
  font-size: 10px;
  color: rgba(61, 232, 245, 0.5);
  letter-spacing: 0.12em;
  text-transform: uppercase;
  display: block;
  margin-bottom: 6px;
  opacity: 0;
  transition: opacity 0.3s 0.1s;
}
.card-22:hover .card-22__label {
  opacity: 1;
}
.card-22__title {
  font-size: 18px;
  font-weight: 700;
  color: #f0eeff;
  margin-bottom: 6px;
  transition: color 0.35s;
}
.card-22__body {
  font-size: 13px;
  color: #b8b6d4;
  line-height: 1.6;
  transition: color 0.35s;
}
.card-22:hover .card-22__title {
  color: #3de8f5;
}
.card-22:hover .card-22__body {
  color: rgba(61, 232, 245, 0.6);
}