maps.chandlerswift.com/style.css

@import 'ol/ol.css';
@import 'ol-contextmenu/ol-contextmenu.css';

html, body {
  margin: 0;
  padding: 0;
}

#map {
  position: absolute;
  top: 0;
  bottom: 0;
  left: 0;
  right: 0;
  transition: 0.25s;
}

.nav-open #map {
  left: min(max(300px, 20%), 400px);
}

aside {
  width: min(max(300px, 20%), 400px);
  margin-left: max(min(-300px, -20%), -400px);
  transition: 0.25s;
  max-height: 100vh;
  overflow-y: auto;
  display: flex;
  flex-direction: column;
}

aside > div {
  padding: 0 0.5em;
}

#source {
  order: 1;
  margin: auto;
  padding: 0.5em;
}

.nav-open aside {
  margin-left: 0;
}

aside ul {
  margin: 0;
  padding: 0;
}

aside ul li {
  list-style: none;
}

h1 {
  text-align: center;
}

aside .close {
  display: none;
}

aside details {
  margin-bottom: 2em;
  cursor: pointer;
}

aside summary {
  font-size: 1.3em;
  margin: .5em 0;
  font-weight: bold;
}

@media (max-width: 400px) {
  .nav-open #map {
    left: 100%;
  }

  aside {
    margin-left: calc(-100% + 2em);
    width: calc(100% - 2em);
  }

  aside .close {
    display: initial;
  }

  .nav-open aside .close {
    position: absolute;
    top: 0.5em;
    right: 0.5em;
  }
}

/* POPUP (from https://openlayers.org/en/latest/examples/popup.html) */
.ol-popup {
  position: absolute;
  background-color: white;
  box-shadow: 0 1px 4px rgba(0,0,0,0.2);
  padding: 15px;
  border-radius: 10px;
  border: 1px solid #cccccc;
  bottom: 12px;
  left: -50px;
  min-width: 280px;
}
.ol-popup:after, .ol-popup:before {
  top: 100%;
  border: solid transparent;
  content: " ";
  height: 0;
  width: 0;
  position: absolute;
  pointer-events: none;
}
.ol-popup:after {
  border-top-color: white;
  border-width: 10px;
  left: 48px;
  margin-left: -10px;
}
.ol-popup:before {
  border-top-color: #cccccc;
  border-width: 11px;
  left: 48px;
  margin-left: -11px;
}
.ol-popup-closer {
  text-decoration: none;
  position: absolute;
  top: 2px;
  right: 8px;
}
.ol-popup-closer:after {
  content: "✖";
}
/* END POPUP */