Can I use custom styles for text content?

[favetelinguis]

Is it possible to change the following CSS?

.item {
  padding: 10px;
  font-weight: 900;
  font-family: 'Lato', sans-serif;
  border-top: 1px solid hsla(0,0%,0%,.1);
  -webkit-font-smoothing: antialiased;
  &__message {
    @extend .item;
    font-size: 0.9rem;
    max-height: $max-height;
    overflow-y: auto;
    border-top: none;
    p:last-child {
      margin-bottom: 0;
    }
  }
  &__btnBar {
    @extend .item;
    margin-top: 10px;
    padding: 0;
  }
}

I find the tex of the message to be way to bold and would like to make it smaller.