antd-mobile/2x/cjs/components/dropdown/dropdown.css

<img src="https://gw.alipayobjects.com/mdn/rms_ee68a8/afts/img/A*hjjDS5Yy-ooAAAAAAAAAAAAAARQnAQ" alt="logo" width="100%" />

.adm-dropdown {
  background-color: white;
}

.adm-dropdown .adm-dropdown-nav {
  display: flex;
}

.adm-dropdown-open .adm-dropdown-nav {
  border-bottom: 2px solid var(--adm-border-color);
}

.adm-dropdown-item {
  display: flex;
  flex: 1;
  justify-content: center;
  min-width: 0;
  cursor: pointer;
}

.adm-dropdown-item .adm-dropdown-item-title {
  display: flex;
  align-items: center;
  position: relative;
  max-width: 100%;
  font-size: 26px;
  padding: 24px;
}

.adm-dropdown-item .adm-dropdown-item-title-text {
  margin-right: 10px;
  overflow: hidden;
  white-space: nowrap;
  text-overflow: ellipsis;
}

.adm-dropdown-item .adm-dropdown-item-title-arrow {
  color: var(--adm-color-light);
  font-size: 18px;
  transform: rotate(0deg) translateY(-2px);
  transition: all ease 0.2s;
}

.adm-dropdown-item .adm-dropdown-item-title-arrow-active {
  transform: rotate(-180deg) translateY(-2px);
}

.adm-dropdown-item .adm-dropdown-item-title:active {
  opacity: 0.7;
}

.adm-dropdown-item-highlight {
  color: var(--adm-color-primary);
}

.adm-dropdown-item-active .adm-dropdown-item-title:after {
  margin-top: -2px;
  transform: rotate(135deg);
}

.adm-dropdown-item-content {
  width: 100%;
  background: white;
}

.adm-dropdown-item-content-hidden {
  display: none;
}

.adm-dropdown-popup {
  position: fixed;
  overflow: hidden;
  width: 100%;
  right: 0;
  bottom: 0;
  left: 0;
}

.adm-dropdown-popup .adm-dropdown-popup-mask {
  position: absolute;
}

.adm-dropdown-popup .adm-dropdown-popup-body {
  position: absolute;
}