edx-platform/common/lib/xmodule/xmodule/css/html/display.scss

// HTML component display:
* {
  line-height: 1.4em;
}

h1 {
    color: $baseFontColor;
    font: normal 2em/1.4em $sans-serif;
    letter-spacing: 1px;
    margin: 0 0 1.416em 0;
  }

h2 {
  color: #646464;
  font: normal 1.2em/1.2em $sans-serif;
  letter-spacing: 1px;
  margin-bottom: 15px;
  text-transform: uppercase;
  -webkit-font-smoothing: antialiased;
}

h3, h4, h5, h6 {
  margin: 0 0 10px 0;
  font-weight: 600;
}

h3 {
  font-size: 1.2em;
}

h4 {
  font-size: 1em;
}

h5 {
  font-size: .83em;
}

h6 {
  font-size: 0.75em;
}

p {
  margin-bottom: 1.416em;
  font-size: 1em;
  line-height: 1.6em !important;
  color: $baseFontColor;
}

em, i {
  font-style: italic;

  span {
    font-style: italic;
  }
}

strong, b {
  font-weight: bold;

  span {
    font-weight: bold;
  }
}

p + p, ul + p, ol + p {
  margin-top: 20px;
}

blockquote {
  margin: 1em 40px;
}

ol, ul {
  margin: 1em 0;
  padding: 0 0 0 1em;
  color: $baseFontColor;

  li {
    margin-bottom: 0.708em;
  }
}

ol {
  list-style: decimal outside none;
}

ul {
  list-style: disc outside none;
}

a {
  &:link, &:visited, &:hover, &:active, &:focus {
    color: #1d9dd9;
  }
}

img {
  max-width: 100%;
}

pre {
  margin: 1em 0;
  color: $baseFontColor;
  font-family: monospace, serif;
  font-size: 1em;
  white-space: pre-wrap;
  word-wrap: break-word;
}

code {
  color: $baseFontColor;
  font-family: monospace, serif;
  background: none;
  padding: 0;
}

table {
  width: 100%;
  margin: 20px 0;
  border-collapse: collapse;
  font-size: 16px;

  td, th {
    margin: 20px 0;
    padding: 10px;
    border: 1px solid #ccc;
    font-size: 14px;

    &.cont-justified-left {
      text-align: left !important; // nasty, but needed to override the bad specificity of the xmodule css selectors
    }

    &.cont-justified-right {
      text-align: right !important; // nasty, but needed to override the bad specificity of the xmodule css selectors
    }

    &.cont-justified-center {
      text-align: center !important; // nasty, but needed to override the bad specificity of the xmodule css selectorsstyles
    }
  }
}

th {
  background: #eee;
  font-weight: bold;
}


// image modal
// --------------------

// modal - image zoom, fill window
.wrapper-modal-image {
  
  .modal-ui-icon {
    position: absolute;
    display: block;
    padding: 5px 7px;
    cursor: pointer;
    border-radius: 5px;
    opacity: .9;
    background: $white;
    color: $black;
    border: 2px solid $black;
    
    .label {
      font-weight: bold;
    }
    
    i {
      font-style: normal;
    }
  }
  
  .image-link {
    position: relative;
    display: block;
    cursor: pointer;
    
    .action-fullscreen {
      display: none;
      top: 10px;
      left: 10px;
    }
    
    &:hover .action-fullscreen {
      display: block;
    }
  }
  
  .image-modal {
    position: fixed;
    top: 0;
    left: 0;
    display: none;
    height: 100%;
    width: 100%;
    @extend %ui-depth5;
    cursor: pointer;
    background-color: rgba(0, 0, 0, 0.7);
  
    .image-content {
      position: relative;
      top: 2.5%;
      display: block;
      height: 95%;
      width: 95%;
      margin: auto;
      overflow: hidden;
      
      .image-wrapper {
        position: relative;
        
        img {
          position: relative;
          display: block;
          max-width: 100%;
          max-height: 100%;
          margin: auto;
          cursor: default;
        }
      }
      
      .action-close {
        top: 10px;
        right: 10px;
      }
      
      .image-controls {
        position: absolute;
        right: 10px;
        bottom: 10px;
        margin: 0;
        padding: 0;
        list-style: none;
          
        .image-control {
          position: relative;
          display: inline-block;
          margin: 0;
          padding: 0;
          
          .modal-ui-icon {
            position: relative;
            
            &.action-zoom-in {
              margin-right: 5px;
            }
            &.action-zoom-out {
              margin-left: 5px;
            }
            &.is-disabled {
              opacity: .5;
              cursor: default;
            }
          }
        }
      }
    }
    
    &.image-is-fit-to-screen {
      display: block;
      
      // !important used here to override jQuery.
      .image-content .image-wrapper {
        top: 0 !important;
        left: 0 !important;
        width: 100% !important;
        height: 100% !important;
        
        img {
          top: 0 !important;
          left: 0 !important;
        }
      }
    }
    &.image-is-zoomed {
      display: block;
      
      .image-content .image-wrapper {
        
        img {
          max-width: none;
          max-height: none;
          margin: 0;
          cursor: move;
        }
      }
    }
  }
}