Just another atom stylesheet..

gistfile1.txt

atom-text-editor::shadow {
  // The cursor line important to use rgba for opacity, also requires !important
  // to override any theme.
  .line.highlight-line {
    background: rgba(135, 135, 135, 0.27) !important;
  }

  // Replace 'solid', with 'dashed' or 'dotted' depending of what you have
  // set in the settings page.

  // This is for the bottom line (underline)
  .line.highlight-line-multi-line-solid-bottom {
    border-bottom-color: rgba(231,76,60,255);
  }

  // This is for the top line when you have the selection borders enabled.
  .line.highlight-line-multi-line-solid-top {
    border-top-color: rgba(231,76,60,255);
  }
  .cursor-line {
    color: white;
    background-color: rgba(231,76,60,255);
  }
}

atom-text-editor[mini] {
  height: auto;
  max-height: none;
}