Gemini Enhancement

Add splitter in canvas mode, Full width layout, always visible scrollbar, and Middle-click New Chat & History

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 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         Gemini Enhancement
// @namespace    Violentmonkey Scripts
// @match        https://gemini.google.com/*
// @grant        GM_addStyle
// @version      1.0.2
// @author       vacnex
// @description  Add splitter in canvas mode, Full width layout, always visible scrollbar, and Middle-click New Chat & History
// ==/UserScript==

(function() {
    'use strict';

    // --- 1. CONFIG ---
    const RESIZER_WIDTH = 16;
    const EL_COLORS = { borderLight: '#e4e7ed', primary: '#409eff', primaryLight: '#a0cfff' };

    GM_addStyle(`
        .genz-resizer { width: ${RESIZER_WIDTH}px; height: 100%; position: relative; cursor: col-resize; user-select: none; touch-action: none; flex: none; z-index: 100; }
        .genz-resizer::before { content: ""; position: absolute; top: 50%; left: 50%; transform: translate(-50%, -50%); width: 1px; height: 100%; background-color: ${EL_COLORS.borderLight}; transition: background-color 0.2s, width 0.2s; }
        .genz-resizer:hover::before, .genz-resizer.active::before { background-color: ${EL_COLORS.primary}; width: 2px; box-shadow: 0 0 4px ${EL_COLORS.primaryLight}; }
        .genz-resize-overlay { position: fixed; top: 0; left: 0; width: 100vw; height: 100vh; z-index: 9999; cursor: col-resize; display: none; }
        .genz-resize-overlay.active { display: block; }
        body.is-resizing * { pointer-events: none !important; user-select: none !important; }
        body.is-resizing .genz-resize-overlay { pointer-events: auto !important; }

        /* UI TWEAKS */
        user-query, .conversation-container, .input-area-container { max-width: unset !important; }
        .input-area-container { margin-bottom: 10px !important; }
        my-stuff-recents-preview, .my-stuff-recents-preview-container { display: none !important; }
        mat-action-list { margin: 0 !important; }
        .overflow-container { padding-top: 60px !important; }
        hallucination-disclaimer { display: none !important; }
        ::-webkit-scrollbar { width: 8px !important; height: 8px !important; }
        ::-webkit-scrollbar-track { background: transparent !important; }
        ::-webkit-scrollbar-thumb { background: #909399 !important; border-radius: 4px !important; }
        ::-webkit-scrollbar-thumb:hover { background: #606266 !important; }
    `);

    const overlay = document.createElement('div');
    overlay.className = 'genz-resize-overlay';
    document.body.appendChild(overlay);

    function getChatIdFromTarget(target) {

        const element = target.closest('[jslog*="c_"]');

        if (!element) return null;

        if (target.closest('.conversation-actions-container')) return null;

        const jslog = element.getAttribute('jslog');
        if (!jslog) return null;

        const match = jslog.match(/c_([a-f0-9]{10,})/);
        return match ? match[1] : null;
    }

    function isNewChatButton(element) {
        return element.closest('side-nav-action-button button') !== null;
    }

    document.addEventListener('mousedown', (e) => {
        if (e.button !== 1) return;

        if (isNewChatButton(e.target) || getChatIdFromTarget(e.target)) {
            e.preventDefault();
            e.stopPropagation();
            e.stopImmediatePropagation();
        }
    }, true);

    document.addEventListener('mouseup', (e) => {
        if (e.button !== 1) return;

        if (isNewChatButton(e.target)) {
            e.preventDefault(); e.stopPropagation();
            window.open('https://gemini.google.com/app', '_blank');
            return;
        }

        const chatId = getChatIdFromTarget(e.target);
        if (chatId) {
            e.preventDefault(); e.stopPropagation();
            window.open(`https://gemini.google.com/app/${chatId}`, '_blank');
        }
    }, true);

    function initResizer(container) {
        if (container.querySelector('.genz-resizer')) return;

        const leftPanel = container.querySelector('div.chat-container');
        const rightPanel = container.querySelector('immersive-panel');

        if (!leftPanel || !rightPanel) return;

        const resizer = document.createElement('div');
        resizer.className = 'genz-resizer';
        container.insertBefore(resizer, rightPanel);

        container.style.gap = '0px';
        const currentLeftWidth = leftPanel.offsetWidth || 360;
        container.style.gridTemplateColumns = `${currentLeftWidth}px ${RESIZER_WIDTH}px 1fr`;

        let isDragging = false;
        let animationFrameId;

        const onMouseDown = (e) => {
            isDragging = true;

            resizer.classList.add('active');
            overlay.classList.add('active');
            document.body.classList.add('is-resizing');
        };

        const onMouseMove = (e) => {
            if (!isDragging) return;

            if (animationFrameId) cancelAnimationFrame(animationFrameId);

            animationFrameId = requestAnimationFrame(() => {
                const containerRect = container.getBoundingClientRect();
                let newWidth = e.clientX - containerRect.left - (RESIZER_WIDTH / 2);

                if (newWidth < 300) newWidth = 300;
                if (newWidth > containerRect.width * 0.85) newWidth = containerRect.width * 0.85;

                container.style.gridTemplateColumns = `${newWidth}px ${RESIZER_WIDTH}px 1fr`;
            });
        };

        const onMouseUp = () => {
            if (isDragging) {
                isDragging = false;

                resizer.classList.remove('active');
                overlay.classList.remove('active');
                document.body.classList.remove('is-resizing');

                if (animationFrameId) cancelAnimationFrame(animationFrameId);
            }
        };

        resizer.addEventListener('mousedown', onMouseDown);

        overlay.addEventListener('mousemove', onMouseMove);
        overlay.addEventListener('mouseup', onMouseUp);

        window.addEventListener('mouseup', onMouseUp);
    }

    const observer = new MutationObserver((mutations) => {
        const immersiveContainer = document.querySelector('chat-window.immersives-mode');
        if (immersiveContainer) {
            initResizer(immersiveContainer);
        }
    });

    observer.observe(document.body, { childList: true, subtree: true });
})();