the-obelisk/sass/_modal.scss

#modalWindow {
  opacity: 0;
  pointer-events: none;
  z-index: 10;
  position: absolute;
  left: 0px;
  right: 0px;
  top: 0px;
  bottom: 0px;
  transition: opacity .3s ease-in-out;
  display: flex;
  align-items: center;
  justify-content: center;
  overflow: hidden;
}

*:not(#modalWindow) {
  transition: filter .3s ease-in-out;
}

body.modal {
  & > *:not(#modalWindow) {
    filter: blur(3px);
  }

  & #modalWindow {
    opacity: 1;
    pointer-events: auto;
  }
}

#modalContent {
  width: auto;
  height: auto;
  max-height: 85%;
  max-width: 85%;
  background: rgba(230,240,255,0.4);
  border: 2px dashed transparent;
  box-shadow: 0px 0px 1px 1px rgba(0,0,0,0.15);
  border-radius: 4px;
  overflow-x: hidden;
  overflow-y: auto;
  padding: 1.6rem;
  padding-top: 0px;
}

#leftWindow , #rightWindow , #currentRoomTab, #hyperlinksTab, #fakeparserTab , #statusLine {
  transition: filter .3s ease-in-out;
}

#mainPage.turn {
  & #leftWindow , #rightWindow , #currentRoomTab, #hyperlinksTab, #fakeparserTab , #statusLine {
    pointer-events: none;
    filter: blur(2px);
  }
}

#mainPage.intro {
  & #leftWindow , #rightWindow, #statusLine {
    display: none;
  }

  & #centerWindow {
    max-width: 100%;
  }
}

#loadingScreen {
  position: absolute;
  left: 0px;
  top: 0px;
  bottom: 0px;
  right: 0px;
  background: linear-gradient(1deg, #FFF, #EEE);
  background-size: 400% 400%;
  z-index: 99999;
}