# Web App - Single Screen
You can create a web app that interacts with your Photon device through Particle Cloud.
Your web app will consist of an HTML file named`index.html`, a CSS file named `style.css`, and a JavaScript file named `script.js`.
If your web app will consist of a **single** screen, you can use the starter code below for your HTML, CSS, and JS files. Then you'll have to add your own code, as well as modify certain parts of the starter code.
If your web app will need **multiple** screens, [use this other starter code instead](/code-internet-of-things/references/web-app-multiple-screens.md).
## HTML
You can use this starter code for your HTML file named `index.html`:
```markup
Smart Device Web App
```
{% hint style="success" %}
**COPY CODE:** When using this IoT code guidebook, you can copy a code block simply by clicking the **copy icon** displayed in the upper right of the code block.
{% endhint %}
This HTML does three main things:
1. It loads a CSS stylesheet file.
2. It loads three JavaScript files.
3. It has blank lines where you'll add HTML for your specific web app.
#### LOAD CSS STYLESHEET
In the `` section, there is a `` tag to load a CSS stylesheet file named `style.css` that you'll use to modify the appearance of certain HTML elements in your web app.
#### LOAD JAVASCRIPT FILES
At the bottom of the `` section, there are `