metamask-extension/ui/app/css/itcss/components/account-menu.scss

.account-menu {
  position: fixed;
  z-index: 100;
  top: 58px;
  width: 310px;

  @media screen and (max-width: 575px) {
    right: calc((100vw - 100%) / 2);
  }

  @media screen and (min-width: 576px) {
    right: calc((100vw - 85vw) / 2);
  }

  @media screen and (min-width: 769px) {
    right: calc((100vw - 80vw) / 2);
  }

  @media screen and (min-width: 1281px) {
    right: calc((100vw - 65vw) / 2);
  }

  &__icon {
    cursor: pointer;
  }

  &__header {
    display: flex;
    flex-flow: row nowrap;
    justify-content: space-between;
    align-items: center;
  }

  &__logout-button {
    border: 1px solid $dusty-gray;
    background-color: transparent;
    color: $white;
    border-radius: 4px;
    font-size: 12px;
    line-height: 23px;
    padding: 0 24px;
  }

  img {
    width: 16px;
    height: 16px;
  }

  &__accounts {
    display: flex;
    flex-flow: column nowrap;
    overflow-y: auto;
    height: 272px;
    position: relative;
    z-index: 200;
  }
}