css - Google apps script: style tags work in index.html but not stylesheet.html -

i'm noob @ gas, please forgive stupid question...

my simple css style works when part of index.html, not when part of stylesheet.html. doing wrong? in advance!

index.html

<script src="https://ajax.googleapis.com/ajax/libs/jquery/1.11.3/jquery.min.js"></script> <link rel="stylesheet" href="https://ajax.googleapis.com/ajax/libs/jqueryui/1.11.4/themes/smoothness/jquery-ui.css"> <script src="https://ajax.googleapis.com/ajax/libs/jqueryui/1.11.4/jquery-ui.min.js"></script>  <script>   $(function() {     $( "#studproptabs" ).tabs();   }); </script>  <div id="studproptabs">   <ul>     <li><a href="#maintab">basic information</a></li>     <li><a href="#schedtab">schedule & course drops</a></li>     <li><a href="#plantab">planning</a></li>     <li><a href="#misctab">off-campus & partner info</a></li>   </ul>   <div id="maintab">     <form id='propform'>       <fieldset>         <div>           <label class='mainform' for='firstname' >first name</label>           <input type='text' id='firstname' />          </div>         <div>           <label class='mainform' for='lastname' >last name</label>           <input type='text' id='lastname' />         </div>       </fieldset>     </form>     </div>   </div> 

stylesheet.html

<!-- css package applies google styling; should included. --> <link rel="stylesheet" href="https://ssl.gstatic.com/docs/script/css/add-ons.css">  <style>  label { display: inline-block; width: 5em; color: red; }  </style> 

code.gs

function doget(e) {   return htmlservice.createhtmloutputfromfile('index')   .settitle('senior project proposal form')   .setsandboxmode(htmlservice.sandboxmode.iframe); } 

there's no page included, must specify it, said in good practices:

in code.gs:

function include(filename) {   return htmlservice.createhtmloutputfromfile(filename)       .setsandboxmode(htmlservice.sandboxmode.iframe)       .getcontent(); } 

in index.html:

<?!= include('stylesheet'); ?>