etherpad-lite/src/static/css/pad/popup.css

.popup {
  position: absolute;
  top: 0;
  right: 20px;
  display: none;
  z-index: 500;
  min-width: 300px;
  max-width: 600px;
  padding: 10px;
  border-radius: 0 0 6px 6px;
  border: 1px solid #ccc;
  border-top: none;
  box-shadow: 0 2px 4px #ddd;
  background: #f7f7f7;
}
.popup input[type=text] {
  width: 100%;
  padding: 5px;
  box-sizing: border-box;
  display: block;
  margin-top: 10px;
}
.popup input[type=text], #users input[type=text] {
  outline: none;
}
.popup a {
  text-decoration: none
}
.popup h1 {
  font-size: 1.8rem;
  margin-bottom: 10px;
}
.popup h2 {
  opacity: .7;
  margin: 10px 0;
  font-size: 1.2rem;
}
.popup p {
  margin: 5px 0;
}
.popup select {
  background: #fff;
  padding: 2px;
  height: 24px;
  border-radius: 3px;
  border: 1px solid #ccc;
  outline: none;
  width: 120px;
}

/* Mobile devices */
@media only screen and (max-width: 720px) {
  .popup {
    border-radius: 0;
    left: 0;
    right: 0;
    max-height: 80vh;
    max-width: none !important;
  }
  /* Move popup to the bottom, except popup linked to left toolbar, like hyperklink popup */
  .popup:not(.hyperlink-dialog):not(.toolbar-popup) {
    top: auto;
    bottom: 0;
    border-radius: 6px 6px 0 0;
    border: 1px solid #ccc;
    border-bottom: none;
    box-shadow: 0 -2px 4px #ddd;
  }

  .toolbar-popup, .hyperlink-dialog {
    left: 0 !important; /* overide javascript positionning */
    right: 0 !important;
  }
}