.round-image img { border-radius: 50%; transition: opacity .25s ease-in-out; }
.round-image img:hover { opacity: .8; }
.col4-grid figure { width: 25%; }
.lightbox {
  opacity: 0;
  position: fixed;
  width: 100%;
  height: 100%;
  top: -100%;
  left: 0;
  background: rgba(10,10,10,.95);
  transition: opacity .5s ease-in-out;
}
.lightbox figure {
  background: inherit;
}
.lightbox figcaption {
  display: block;
  text-align: center;
  font-size: inherit;
  margin-top: .75em;
}
.lightbox img {
  display: block;
  margin: 0 auto;
  max-width: 100%;
  max-height: 90vh;
}

/* lightbox when targeted */
.lightbox:target {
  opacity: 1;
  top: 0;
  z-index: 1000;
}
.lightbox:target figure {
  display: block;
}
.lightbox:target figcaption {
  color: var(--subtleBlue);
  max-width: 850px;
  margin: .25em auto;
}