hacks-guide-minimal-mistakes-theme/_assets/css/_sidebar.scss

/* ==========================================================================
   SIDEBAR
   ========================================================================== */

.sidebar {
  @include grid(12,10);
  @include prefix(12,1);
  @include suffix(12,1);
  margin-bottom: 1em;
  @include breakpoint($small) {
    display: block;
    @include grid(12,2);
    @include prefix(12,0.5);
    @include suffix(12,0.5);
  }
  @include breakpoint($x-large) {
    @include grid(12,1.5);
    @include prefix(12,2);
  }
  h2, h3, h4, h5, h6 {
    font-family: $sans-serif-narrow;
  }
  p, li {
    font-size: 14px;
  }
  img {
    width: 100%;
  }
}

/*
   Author profile and links
   ========================================================================== */

.author__name {
  margin-bottom: 0;
  font-family: $sans-serif-narrow;
  font-size: 18px;
  @include breakpoint($small) {
    margin-top: 10px;
    margin-bottom: 10px;
    font-size: 24px;
  }
}

.author__bio {
  display: none;
  @include breakpoint($small) {
    display: block;
    margin-bottom: 20px;
    font-size: 80%;
    font-style: italic;
  }
}

.author__avatar {
  display: none;
  @include breakpoint($small) {
    max-width: 110px;
    border-radius: 50%;
  }
}
.author__social-url {
  display: inline-block;
  margin-bottom: 5px;
  padding-right: 5px;
  font-size: 14px;
  color: #000;
  text-decoration: none;
  @include breakpoint($small) {
    display: block;
  }
  &:hover {
    text-decoration: underline;
  }
}

.author__name,
.author__avatar,
.author__bio,
.author__social-url {
  @include breakpoint($small) {
    display: block;
    max-width: 125px;
  }
  @include breakpoint($large) {
    max-width: 150px;
  }
}