html, body {
  margin: 0;
  padding: 0;
}

.scroll {
  overflow-y: scroll;
  position: fixed;
  top: 0px;
  bottom: 0px;
  right: 0px;
}

button {
  border-radius: 5px;
}
canvas {
  display: block;
}


.bg-gray{
  background-color: #cccccc;
}

.bg-blue{
  border-radius: 5px;
  background-color: #337ab7;
}

.btn-blue{
  border-radius: 5px;
  text-align: center;
  background-color: #337ab7;
  color: #fff;
  position: relative;
  margin-block: 5px;
  margin-inline: 2px;
  padding: 0px;
}
.btn-blue:hover{
  background-color: #7fafda;
}