div[data-testid="sidebarColumn"] {
    display: none !important;
}

/* 隐藏左侧导航栏 */
header[role="banner"],
div[data-testid="sidebarColumn"] {
    display: none !important;
}

/* 调整内容区域宽度 */
div[data-testid="primaryColumn"] {
    max-width: 100% !important;
    width: 100% !important;
}

// ==UserScript==
// @name         Twitter Hide Sidebar
// @namespace    http://tampermonkey.net/
// @version      0.1
// @description  隐藏Twitter侧边栏
// @author       You
// @match        https://twitter.com/*
// @match        https://*.twitter.com/*
// @grant        none
// ==/UserScript==

(function() {
    'use strict';
    const style = document.createElement('style');
    style.textContent = `
        div[data-testid="sidebarColumn"] {
            display: none !important;
        }
        div[data-testid="primaryColumn"] {
            max-width: 100% !important;
            width: 100% !important;
        }
    `;
    document.head.appendChild(style);
})();

javascript:(function(){document.querySelector('div[data-testid="sidebarColumn"]').style.display='none';document.querySelector('div[data-testid="primaryColumn"]').style.maxWidth='100%';})()