ContrAtom/styles/markdown-preview.less

// Global Markdown Preview styles

.markdown-preview {
  atom-text-editor {
    // only show scrollbars on hover
    .scrollbars-visible-always & {
      .vertical-scrollbar,
      .horizontal-scrollbar {
        visibility: hidden;
      }
    }

    .scrollbars-visible-always &:hover {
      .vertical-scrollbar,
      .horizontal-scrollbar {
        visibility: visible;
      }
    }

    user-select: auto;
  }

  // move task list checkboxes
  .task-list-item input[type=checkbox] {
    position: absolute;
    margin: .25em 0 0 -1.4em;
  }

  .task-list-item {
    list-style-type: none;
  }
}

.markdown-spinner {
  margin: auto;
  background-image: url(images/octocat-spinner-128.gif);
  background-repeat: no-repeat;
  background-size: 64px;
  background-position: top center;
  padding-top: 70px;
  text-align: center;
}

// style the background color of the tree view
.tree-view {
  // background-color: whitesmoke;
}

// style the background and foreground colors on the atom-text-editor-element itself
atom-text-editor {
  // color: white;
  // background-color: hsl(180, 24%, 12%);
}

// To style other content in the text editor's shadow DOM, use the ::shadow expression
atom-text-editor::shadow .cursor {
  // border-color: red;
}

.markdown-preview-custom {
  // please write your custom style here
  // eg:
  //  color: blue;          // change font color
  //  font-size: 14px;      // change font size
  //

  // custom pdf output style

  h1 {
    counter-increment: h1counter;
    counter-reset: h2counter;
  }

  h2 {
    counter-increment: h2counter;
    counter-reset: h3counter;
  }

  h3 {
    counter-increment: h3counter;
    counter-reset: h4counter;
  }

  h4 {
    counter-increment: h4counter;
    counter-reset: h5counter;
  }

  h1:before {
    content: counter(h1counter) ". ";
  }

  h2:before {
    content: counter(h1counter) "." counter(h2counter) ". ";
  }

  h3:before {
    content: counter(h1counter) "." counter(h2counter) "." counter(h3counter) ". ";
  }

  h4:before {
    content: counter(h1counter) "." counter(h2counter) "." counter(h3counter) "." counter(h4counter) ". ";
  }

  @media print {

  }

  // custom phantomjs png/jpeg export style
  &.phantomjs-image {

  }

  //custom phantomjs pdf export style
  &.phantomjs-pdf {

  }

  // custom presentation style
  .preview-slides .slide,
  &[data-presentation-mode] {
    // eg
    // background-color: #000;
  }
}

.markdown-preview {
  .markdown-preview-custom() !important;
}