JSFiddle - React, Tailwind, and code Playground

HTML

<script src="https://cdnjs.cloudflare.com/ajax/libs/phaser/2.6.2/phaser.min.js"></script>
<body>
</body>

CSS

canvas {
				position: relative;
				margin: 0 auto;
			}

JavaScript

var game = new Phaser.Game(window.innerWidth, 300, Phaser.AUTO, 'phaser-example', { create: create });

var healthBar;
var attackBtn;

var hp_status_text;

var maxHealth = 100;
var health = 100;

var config = {
	hpBar: null,
	atckBtn: null
}

function create() {
	addHealthBar({
		pos: {
			x: game.world.centerX,
			y: 20
		},
		size: {
			w: game.world.width  - 40,
			h: 20,
			_1p: 0 /// will be calculated later
		},
		fill_c: 0x00cc00,
		border_c: 0x80ff80,
		alpha: 0.7
	});
	
	addAttackButton({
		pos: {
			x: game.world.centerX,
			y: 65
		},
		size: {
			w: 90,
			h: 35,
		},
		fill_c: 0xff1a1a,
		border_c: 0xff8080,
		alpha: 0.7
	});
}

/////// [ Health Bar  ] ///////////////////

function takeDamage( damage ){
	if( Math.floor(health) > 0 ){
		health -= damage;
	}else{
		console.log("dead");
	}
	let hp_p = ( health / maxHealth ) * 100;
	updateHealthBar( hp_p );
}

function addHealthBar( cfg ){
	config.hpBar = cfg;
	config.hpBar.pos.x -= ( config.hpBar.size.w / 2 ); /// center on X axis ////
	config.hpBar.size._1p = config.hpBar.size.w * 0.01; ///// 1% of width ///
	
	healthBar = game.add.graphics( config.hpBar.pos.x, config.hpBar.pos.y ); 
	hp_status_text = game.make.text( 0 , 0, "", { font: "bold 22px Arial", fill: "#FFF",  boundsAlignH: "center", boundsAlignV: "middle"} );
	hp_status_text.setTextBounds(0, 2, config.hpBar.size.w, config.hpBar.size.h);
	healthBar.addChild(hp_status_text);
	
	updateHealthBar( 100 ); /// 100 % life ////
}

function updateHealthBar( hp_p ){ //// health percentage 
	healthBar.clear();
	hp_status_text.setText( Math.floor(hp_p)+"%" );
	healthBar.lineStyle( 2, config.hpBar.border_c, config.hpBar.alpha );
	healthBar.beginFill( config.hpBar.fill_c, config.hpBar.alpha );
	healthBar.drawRect( 0, 0, hp_p * config.hpBar.size._1p , config.hpBar.size.h );
	healthBar.endFill();
}
/////// [ Health Bar  ] ///////////////////


/////// [ Attack Button  ] ///////////////////
function addAttackButton( cfg ){
	config.atckBtn =...