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M365 Copilot Chat Full Width

Expands M365 Copilot Chat to the available page width while retaining modest page margins.

You will need to install an extension such as Tampermonkey, Greasemonkey or Violentmonkey to install this script.

You will need to install an extension such as Tampermonkey or Violentmonkey to install this script.

You will need to install an extension such as Tampermonkey or Violentmonkey to install this script.

You will need to install an extension such as Tampermonkey or Userscripts to install this script.

You will need to install an extension such as Tampermonkey to install this script.

You will need to install a user script manager extension to install this script.

(I already have a user script manager, let me install it!)

You will need to install an extension such as Stylus to install this style.

You will need to install an extension such as Stylus to install this style.

You will need to install an extension such as Stylus to install this style.

You will need to install a user style manager extension to install this style.

You will need to install a user style manager extension to install this style.

You will need to install a user style manager extension to install this style.

(I already have a user style manager, let me install it!)

// ==UserScript==
// @name         M365 Copilot Chat Full Width
// @namespace    http://tampermonkey.net/
// @version      3.1
// @description  Expands M365 Copilot Chat to the available page width while retaining modest page margins.
// @author       hiyun1137 GPT 5.6 Think
// @match        https://m365.cloud.microsoft/*
// @match        https://*.m365.cloud.microsoft/*
// @match        https://microsoft365.com/*
// @match        https://www.microsoft365.com/*
// @grant        GM_addStyle
// @run-at       document-start
// @license      MIT
// ==/UserScript==


(() => {
  const style = document.createElement('style');
  style.textContent = `
    #m365-copilot-app-layout-content {
      width: 100% !important;
      max-width: none !important;
      padding-inline: clamp(12px, 1.5vw, 24px) !important;
      box-sizing: border-box !important;
    }

    /* Widen the real chat branch, located by the stable composer ID. */
    #m365-copilot-app-layout-content :has(#m365-chat-input-shared-container) {
      width: 100% !important;
      max-width: none !important;
      margin-inline: 0 !important;
      box-sizing: border-box !important;
    }

    /* Copilot applies the remaining reading-width cap below that branch. */
    #m365-copilot-app-layout-content div {
      max-width: none !important;
    }

    #m365-chat-input-shared-container,
    [data-test-id="chat-input-wrapper"] {
      width: 100% !important;
      max-width: none !important;
    }

    @media (max-width: 700px) {
      #m365-copilot-app-layout-content { padding-inline: 10px !important; }
    }
  `;
  (document.head || document.documentElement).appendChild(style);
})();