@font-face {
  font-family: NotoSans;
  src: url('font/NotoSansJP-Regular.ttf');
}

body {
  overflow: hidden;
  user-select: none;
  margin: 0;
  width: 100vw;
  height: 100vh;
}

#canvas {
  position: fixed;
  top: 0;
  left: 0;
  width: 100%;
  height: 100%;
}

#overlay {
  position: fixed;
  top: 0;
  left: 0;
  width: 100%;
  height: 100%;
  pointer-events: none;
  z-index: 5;
}

.textbox {
  position: absolute;
  min-width: 100px;
  max-width: 400px;
  margin-top: 20px;
  padding: 15px 20px;
  z-index: 10;
  font-size: 20px;
  font-family: NotoSans, 'Lucida Console', sans-serif;
  color: #333;
  background-color: rgba(255, 255, 255, 0.87);
  filter: drop-shadow(0 4px 10px rgba(0, 0, 0, 0.15));
  border-radius: 20px;
  opacity: 0;
  transition: all 0.5s;
  line-height: 1.5;
}

.textbox::after {
  content: '';
  position: absolute;
  width: 0;
  height: 0;
  top: 20px;
  left: -20px;
  border-style: solid;
  border-width: 6px 20px 6px 0;
  border-color: transparent;
  border-right-color: rgba(255, 255, 255, 0.87);
}