mastodon/app/javascript/styles/contrast/diff.scss

// components.scss
.compose-form {
  .compose-form__modifiers {
    .compose-form__upload {
      &-description {
        input {
          &::placeholder {
            opacity: 1.0;
          }
        }
      }
    }
  }
}

.rich-formatting a,
.rich-formatting p a,
.rich-formatting li a,
.landing-page__short-description p a,
.status__content a,
.reply-indicator__content a {
  color: lighten($ui-highlight-color, 12%);
  text-decoration: underline;

  &.mention {
    text-decoration: none;
  }

  &.mention span {
    text-decoration: underline;

    &:hover,
    &:focus,
    &:active {
      text-decoration: none;
    }
  }

  &:hover,
  &:focus,
  &:active {
    text-decoration: none;
  }

  &.status__content__spoiler-link {
    color: $secondary-text-color;
    text-decoration: none;
  }
}

.status__content__read-more-button {
  text-decoration: underline;

  &:hover,
  &:focus,
  &:active {
    text-decoration: none;
  }
}

.getting-started__footer a {
  text-decoration: underline;

  &:hover,
  &:focus,
  &:active {
    text-decoration: none;
  }
}