metamask-extension/ui/app/css/itcss/components/header.scss

.app-header {
  align-items: center;
  background: $gallery;
  position: relative;
  z-index: $header-z-index;
  display: flex;
  flex-flow: column nowrap;
  width: 100%;
  flex: 0 0 auto;

  @media screen and (max-width: 575px) {
    padding: 12px;
    box-shadow: 0 0 0 1px rgba(0, 0, 0, .08);
    z-index: $mobile-header-z-index;
  }

  @media screen and (min-width: 576px) {
    height: 75px;
    justify-content: center;

    &--back-drop {
      &::after {
        content: '';
        position: absolute;
        width: 100%;
        height: 32px;
        background: $gallery;
        bottom: -32px;
      }
    }
  }

  &__metafox {
    cursor: pointer;
  }

  &__beta-label {
    font-family: Roboto;
    text-transform: uppercase;
    font-weight: 500;
    font-size: .8rem;
    color: $buttercup;
    margin-left: 5px;
    line-height: initial;

    @media screen and (max-width: 575px) {
      display: none;
    }
  }

  &__contents {
    display: flex;
    justify-content: space-between;
    flex-flow: row nowrap;
    width: 100%;

    @media screen and (max-width: 575px) {
      height: 100%;
    }

    @media screen and (min-width: 576px) {
      width: 85vw;
    }

    @media screen and (min-width: 769px) {
      width: 80vw;
    }

    @media screen and (min-width: 1281px) {
      width: 62vw;
    }
  }

  &__logo-container {
    display: flex;
    flex-direction: row;
    align-items: center;
    cursor: pointer;
  }

  &__account-menu-container {
    display: flex;
    flex-flow: row nowrap;
    align-items: center;
  }
}

.app-header h1 {
  font-family: Roboto;
  text-transform: uppercase;
  font-weight: 400;
  font-size: 1.1rem;
  position: relative;
  padding-left: 15px;
  color: #5b5d67;

  @media screen and (max-width: 575px) {
    display: none;
  }
}

h2.page-subtitle {
  text-transform: uppercase;
  color: #aeaeae;
  font-size: 1em;
  margin: 12px;
}

.network-component-wrapper {
  display: flex;
  flex-direction: row;
  align-items: center;
}