PreMiD/Extension/css/popup.css

html,
body {
  margin: 0;
  padding: 0;
  height: 0;
  width: 325px;
  background-color: #282828;
}

#header {
  height: 50px;
  background-color: #596cae;
  color: white;
  text-align: center;
  line-height: 50px;
}

#header h1 {
  margin: 0;
  font-weight: 900;
  display: inline;
}

#header h1:last-child {
  position: absolute;
  font-weight: 700;
  float: right;
  right: 10px;
}

#content {
  margin-top: 10px;
  margin-bottom: 10px;
}

#panel {
  transition: 0.5s all cubic-bezier(0.175, 0.885, 0.32, 1.275);
  display: inline-block;
  margin: 5px;
  width: 150px;
  height: 125px;
  background-color: #596cae;
  border-radius: 5px;
  color: white;
  text-align: center;
}

#panel:not(.open) {
  cursor: pointer;
}

#panel:not(.open):hover {
  transform: scale(1.05);
}

#panel #icon {
  margin-top: 25px;
  width: 50px;
  height: 50px;
  font-size: 50px;
}

.about {
  background-color: #ff9d09 !important;
}

.options {
  background-color: #7a7a7a !important;
}

.github {
  background-color: #fa503c !important;
}

.open {
  position: fixed;
  transition: 0.5s all ease-out;
  transform: scale(5);
  cursor: default;
}

.open * {
  transition: 0.15s all ease-out;
  opacity: 0;
}

.panelContent {
  position: relative;
  color: white;
}

.panelContent:not(.open) {
  display: none;
}

.panelContent.open {
  display: block;
}