ol-ext/examples/control/map.switcher2.css

.ol-layerswitcher.ol-collapsed {
  min-width: unset;
}
.ol-layerswitcher,
.ol-layerswitcher.ol-forceopen {
  min-width: 20em;
}

.ol-layerswitcher > ul.panel {
  overflow-y: auto;
  box-sizing: border-box;
}

.ol-layerswitcher li .li-content {
  width: calc(100% - 3em);
}

.ol-layerswitcher li .li-content label {
  width: 60%;
  box-sizing: border-box;
  vertical-align: middle;
  margin: .6em 0;
}

.ol-control.ol-layerswitcher .panel-container {
  padding-right: 0;
}

.ol-layerswitcher .panel li .layerswitcher-opacity {
  width: 40%;
  display: inline-block;
  vertical-align: middle;
  box-sizing: border-box;
  vertical-align: middle;
  margin: 0;
}
.ol-layerswitcher .layerswitcher-opacity {
  border:0;
  background: none;
  height: 1em;
  box-shadow: none;
}
.ol-layerswitcher .layerswitcher-opacity:before {
  content: "";
  width: 100%;
  height: 3px;
  background: #017eff;
  position: absolute;
  top: 50%;
  -webkit-transform: translateY(-50%);
  transform: translateY(-50%);
  border: 1px solid #017eff;
  box-sizing: border-box;
}
.ol-layerswitcher .layerswitcher-opacity .layerswitcher-opacity-cursor {
  width: auto;
  transform: translateY(-50%);
  height: 3px;
  right: 0;
  background: #666;
  border-radius: 0;
}
.ol-touch .ol-layerswitcher .layerswitcher-opacity .layerswitcher-opacity-cursor,
.ol-layerswitcher .layerswitcher-opacity .layerswitcher-opacity-cursor:before {
  position: absolute;
  transform: translate(-50%,-50%);
  width: 6px;
  height: 16px;
  left: -1px;
  border-radius: 0;
  background: #017eff;
}
.ol-layerswitcher .layerswitcher-opacity-label {
  display: block;
  right: 20%;
  bottom: 70%;
  font-size: 0.6em;
  user-select: none;
  -webkit-transform: translateX(50%);
  transform: translateX(50%);
}

.ol-layerswitcher .layerup {
  width: 2em;
  background: none;
  position: absolute;
  right: .5em;
}
.ol-layerswitcher .layerup:after {
  content:none;
}
.ol-layerswitcher .layerup:before {
  color: #017eff;
  content: "\F0C9";
  font-family: FontAwesome;
  border: 0;
  top: 50%;
  transform: translateY(-50%);
  height: 1em;
  left: .5em;
}

.ol-layerswitcher [type=checkbox]+label:before, 
.ol-layerswitcher [type=radio]+label:before {
  content: '';
  border: 2px solid #ccc;
  background-color: transparent;
}
.ol-layerswitcher [type=checkbox]:checked+label:before, 
.ol-layerswitcher [type=radio]:checked+label:before {
  background: #017eff;
  border-color: #017eff;
} 
.ol-layerswitcher [type=checkbox]:checked+label:after{
  content: "\2713";
  color: #fff;
  position: absolute;
  top: -.15em;
  left: 0.25em;
  cursor: pointer;
  font-weight: 900;
  text-shadow: 1px 1px #fff;
  font-size: 1.2em;
  transform: none;
  border: 0;
  box-shadow: unset;
}

.ol-layerswitcher [type="radio"]:checked+label:after {
  content: none;
}

.ol-control.ol-layerswitcher {
  background: #017eff;
  right: 0;
  border-radius: 0;
}
.ol-layerswitcher button,
.ol-layerswitcher button:focus,
.ol-layerswitcher button:hover {
  background: #017eff;
  border: 0;
  user-select: none;
  outline: none;
}
.ol-layerswitcher button:before {
  background: #017eff;
  -webkit-box-shadow: 0.1em 0.1em #fff;
  box-shadow: 0.1em 0.1em #fff;
}
.ol-layerswitcher button:after {
  background: #fff;
  background-image: none;
}

.ol-layerswitcher .ol-layer-group {
  margin-top: 1em;
}
.ol-layerswitcher .ol-layer-group > .ol-layerswitcher-buttons .layerInfo {
  display: none;
}
.ol-layerswitcher .expend-layers:before, .ol-layerswitcher .collapse-layers:before {
  content: "";
  position: absolute;
  top: 50%;
  left: 0;
  margin-top: -2px;
  height: 4px;
  width: 100%;
  background: #369;
}
.ol-layerswitcher .expend-layers, 
.ol-layerswitcher .collapse-layers {
  top: -1em;
}
.ol-layerswitcher .expend-layers:before, 
.ol-layerswitcher .expend-layers:after, 
.ol-layerswitcher .collapse-layers:before, 
.ol-layerswitcher .collapse-layers:after {
  background: #017eff;
}
.ol-layerswitcher .panel ul {
  overflow: visible;
}
.ol-layerswitcher .layerInfo {
  right: 0;
  background: #017eff;
}

.ol-control.ol-layerswitcher .ol-switchertopdiv, 
.ol-control.ol-layerswitcher .ol-switcherbottomdiv {
  display: none!important;
}