niivue.css

html {
  height: auto;
  min-height: 100%;
  margin: 0;
}
body {
  display: flex;
  flex-direction: column;
  margin: 0;
  min-height: 100%;
  width: 100%;
  position: absolute;
  font-family: system-ui, Arial, Helvetica, sans-serif;
  user-select: none; /* Standard syntax */
  color: white;
  background: #202020;
}
header {
  margin: 10px;
}
main {
  flex: 1;
  background: #000000;
  position: relative;
}
footer {
  margin: 10px;
}
canvas {
  position: absolute;
  cursor: crosshair;
}
canvas:focus {
  outline: 0px;
}
div {
  display: table-row;
}
.dropdown {
  float: left;
  overflow: hidden;
}
.dropdown .dropbtn {
  font-size: 16px;
  border: none;
  outline: none;
  color: white;
  padding: 12px 12px;
  background-color: #202020;
  font-family: inherit;
  margin: 0;
}
.dropdown:hover .dropbtn {
  background-color: #9a9;
}
.dropdown-content {
  display: none;
  position: absolute;
  background-color: #303030;
  min-width: 160px;
  border-radius: 5px;
  box-shadow: 0px 8px 16px 0px rgba(0, 0, 0, 0.2);
  z-index: 1;
}
.dropdown-content a {
  float: none;
  color: white;
  padding: 12px 16px;
  text-decoration: none;
  display: block;
  text-align: left;
  line-height: 6px;
}
.dropdown-content a:hover {
  background-color: #aba;
}
.dropdown:hover .dropdown-content {
  display: block;
}
.dropdown-item-checked::before {
  position: absolute;
  left: 0.2rem;
  content: "\2022"; /* or '✓' */
  font-weight: 600;
}
.divider {
  border-top: 1px solid grey;
}
.vertical-divider {
  border-left: 1px solid grey;
  height: 40px;
}
.help-text {
  margin: auto;
  max-width: 150px;
  padding: 0 10px;
}
.slidecontainer {
  padding: 10px 10px;
  white-space: normal;
  word-break: break-word;
  display: flex;
  align-items: center;
  flex: 0 0 auto;
}

.loading-circle {
  display: inline-block;
  width: 20px;
  height: 20px;
  border: 3px solid rgba(255, 255, 255, 0.3);
  border-radius: 50%;
  border-top-color: #fff;
  animation: spin 1s ease-in-out infinite;
  margin-left: 10px;
  vertical-align: middle;
}

@keyframes spin {
  to {
    transform: rotate(360deg);
  }
}

.hidden {
  display: none;
}