metamask-extension/ui/app/components/modals/customize-gas/index.scss

.customize-gas {
  border: 1px solid #D8D8D8;
  border-radius: 4px;
  background-color: #FFFFFF;
  box-shadow: 0 2px 4px 0 rgba(0,0,0,0.14);
  font-family: Roboto;
  display: flex;
  flex-flow: column;

  @media screen and (max-width: $break-small) {
    width: 100vw;
    height: 100vh;
  }

  &__header {
    height: 52px;
    border-bottom: 1px solid $alto;
    display: flex;
    align-items: center;
    justify-content: space-between;
    font-size: 22px;

    @media screen and (max-width: $break-small) {
      flex: 0 0 auto;
    }
  }

  &__title {
    margin-left: 19.25px;
  }

  &__close::after {
    content: '\00D7';
    font-size: 1.8em;
    color: $dusty-gray;
    font-family: sans-serif;
    cursor: pointer;
    margin-right: 19.25px;
  }

  &__content {
    display: flex;
    flex-flow: column nowrap;
    height: 100%;
  }

  &__body {
    display: flex;
    margin-bottom: 24px;

    @media screen and (max-width: $break-small) {
      flex-flow: column;
      flex: 1 1 auto;
    }
  }

  &__footer {
    height: 75px;
    border-top: 1px solid $alto;
    display: flex;
    align-items: center;
    justify-content: space-between;
    font-size: 22px;
    position: relative;

    @media screen and (max-width: $break-small) {
      flex: 0 0 auto;
    }
  }

  &__buttons {
    display: flex;
    justify-content: space-between;
    margin-right: 21.25px;
  }

  &__revert, &__cancel, &__save, &__save__error {
    display: flex;
    justify-content: center;
    align-items: center;
    padding: 0 3px;
    cursor: pointer;
  }

  &__revert {
    color: $silver-chalice;
    font-size: 16px;
    margin-left: 21.25px;
  }

  &__cancel, &__save, &__save__error {
    width: 85.74px;
    min-width: initial;
  }

  &__save__error {
    opacity: 0.5;
    cursor: auto;
  }

  &__error-message {
    display: block;
    position: absolute;
    top: 4px;
    right: 4px;
    font-size: 12px;
    line-height: 12px;
    color: $red;
  }
}