Expands M365 Copilot Chat to the available page width while retaining modest page margins.
// ==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);
})();