JSFiddle - React, Tailwind, and code Playground

HTML

<link rel="stylesheet" href="http://dev.sencha.com/deploy/ext-4.1.0-gpl/resources/css/ext-all.css">

JavaScript

Ext.onReady(function() {
    var innerContainer = Ext.create('Ext.container.Container', {

        layout: {
            type: 'vbox',
            align: 'stretch'
        },
        items: [{
            xtype: 'container',
            flex: 1,
            layout: { 
                type: 'hbox',
                align: 'stretch'
            },
            items: [{
                xtype: 'panel',
                title: '1',
                flex: 1},
            {
                xtype: 'panel',
                title: '2',
                flex: 1}]},
        {
            xtype: 'container',
            flex: 1,
            layout: { 
                type: 'hbox',
                align: 'stretch'
            },
            items: [{
                xtype: 'panel',
                title: '3',
                flex: 1},
            {
                xtype: 'panel',
                title: '4',
                flex: 1}]},
        {
            xtype: 'container',
            flex: 1,
            layout: { 
                type: 'hbox',
                align: 'stretch'
            },
            items: [{
                xtype: 'panel',
                title: '5',
                flex: 1},
            {
                xtype: 'panel',
                title: '6',
                flex: 1}]},
        {
            xtype: 'container',
            flex: 1,
            layout: { 
                type: 'hbox',
                align: 'stretch'
            },
            items: [{
                xtype: 'panel',
                title: '7',
                flex: 1},
            {
                xtype: 'panel',
                title: '8',
                flex: 1}]}]
    });

    var viewPort = Ext.create('Ext.container.Viewport', {
        layout: 'fit',
        items: innerContainer,
        renderTo: Ext.getBody()
    });
});