I like how in development cocos creator handle different devices and screen sizes in browser mode. But when you build, it creates kinda 2 different version (one for mobile one for desktop). I wish if I could have the development version instead. does anyone have their own way of achieving that? Please, share if you got anything. Thank You.
No one replied 
So, here’s my solution -
First Build for Desktop
- add Vue in index.html =>
<script src="https://cdn.jsdelivr.net/npm/vue"></script> - create style.js file => style.js
- add style.js at the end of index.hml =>
<script src="custom/style.js"></script> - change index.html =>
<div id="app"> <div id="GameDiv" style="width:400px; height: 600px;"> <canvas id="GameCanvas" :width="gameWidth" :height="gameHeight"></canvas> <div id="splash"> <div class="progress-bar stripes"> <span style="width: 0%"></span> </div> </div> </div> </div> - add custom style.css for better view => style.css
- place your splash image at the same folder as css.
It’s better if you customized for your needs.