Here’s a step-by-step guide…
Remember to review the permissions requested by any browser extension before installing it.
Also, ensure you understand the styles/scripts that you install.Depending on the permissions allowed and custom code being added,
one might expose one’s personal data.While i can attest that there is nothing malicious in this “Widescreen Kite on Zerodha” style, being discussed above in this topic-thread, scammers/hackers will also say the same about something that they might be pushing.
Step1. Can install the stylus browser extension for the browser.
-
Chrome Web Store
https://chromewebstore.google.com/detail/stylus/clngdbkpkpeebahjckkjfobafhncgmne -
Firefox add-ons
Stylus – Get this Extension for
Firefox (en-US)
Source: GitHub - openstyles/stylus: Stylus - Userstyles Manager
Step2. Can install the “Widescreen Kite for Zerodha” style in the browser.
Visit Widescreen Kite on Zerodha — UserStyles.world and…
2.1 Choose to install the custom style
2.2 In the stylus extension settings page that pops-up, confirm to Install the custom style
2.3 Then in a Browser window/tab with kite.zerodha.com open,
ensure that the Stylus extension is enabled, and the custom style is applied.
If required, refresh the window/tab once.
If all went well, in each of the above steps,
most of the width of the display/window/screen should now be used up by the chart. 
Note: The proposed/upcoming “Terminal mode” feature
might be the officially supported way to achieve this in the long-term.