src/theme/BlogPostItem/Header/Title/styles.module.css

/**
 * Copyright (c) Facebook, Inc. and its affiliates.
 *
 * This source code is licensed under the MIT license found in the
 * LICENSE file in the root directory of this source tree.
 */

.blogPostTitle {
  font-size: 3rem;
}
.blogPostTitleLink {
  color: var(--ifm-heading-color);
  font-weight: 500;
  position: relative;
  transition: 0.5s;
}
.blogPostTitleLink a {
  color: var(--ifm-heading-color);
  font-weight: 500;
  position: relative;
  transition: 0.5s;
}

.blogPostTitleLink:hover {
  color: var(--ifm-color-primary);
  text-decoration: none;
}

.blogPostTitleLink:hover:after {
  -webkit-transform: scaleX(1);
  transform: scaleX(1);
  visibility: visible;
}

.blogPostTitleLink:after {
  background: var(--ifm-color-primary);
  bottom: 0;
  content: "";
  height: 2px;
  left: 0;
  position: absolute;
  -webkit-transform: scaleX(0);
  transform: scaleX(0);
  transition: 0.3s linear;
  visibility: hidden;
  width: 100%;
}

/**
  Blog post title should be smaller on smaller devices
**/
@media (max-width: 576px) {
  .title {
    font-size: 2rem;
  }
}