.selectbox {
  display: block;
  position: relative;
  border: 1px solid #ccc;
  border-radius: 5px;
  box-sizing: border-box;
  padding: 8px;
  min-width: 50px;
  user-select: none;
  cursor: pointer;
  background-color: white;
}
.selectbox.opened {
  background: linear-gradient(180deg, rgb(251, 251, 251) 34%, rgb(219, 219, 219) 100%);
}
.selectbox.disabled {
  background-color: #e9e9e9;
}
.selectbox.disabled > span {
  color: #505050;
}
.selectbox::after {
  content: "";
  position: absolute;
  top: calc(50% - 0.5em);
  left: 10px;
  width: 9px;
  height: 10px;
  border-radius: 0 0 3px 0;
  border: solid #a3a3a3;
  border-width: 0 2px 2px 0;
  transform: rotate(45deg);
}
.selectbox > span {
  font-size: 0.91em;
}
.selectbox > ul {
  display: none;
}

#selectbox-pupop {
  display: none;
  position: fixed;
  background-color: white;
  border: 1px solid rgb(223, 223, 223);
  border-radius: 4px;
  list-style: none;
  z-index: 2000;
  box-shadow: 0px 3px 10px 2px #e5e5e5;
  overflow: auto;
}
#selectbox-pupop.show {
  display: block;
}
#selectbox-pupop > * {
  display: block;
  padding: 8px;
  margin: 0;
  background-color: white;
  width: 100%;
  box-sizing: border-box;
  user-select: none;
  cursor: pointer;
}
#selectbox-pupop > *:hover {
  background-color: #e7e7e7;
}