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Here you can Sed posuere consectetur est at lobortis. Donec ullamcorper nulla non metus auctor fringilla. Maecenas sed diam eget risus varius blandit sit amet non magna. Donec id elit non mi porta gravida at eget metus. Praesent commodo cursus magna, vel scelerisque nisl consectetur et.

            
              body {
	background-image: linear-gradient(6deg, #214, #000);
	background-size: 100% 100%;
}

canvas { display: block; }
            
          
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              class Vector2 {
	constructor(x = 0, y = 0) {
		this.x = x;
		this.y = y;
	}
	
	add(v) {
		this.x += v.x;
		this.y += v.y;
		return this;
	}
	
	multiplyScalar(s) {
		this.x *= s;
		this.y *= s;
		return this;
	}
	
	clone() {
		return new Vector2(this.x, this.y);
	}
}

class Time {
	constructor() {
		const now = Time.now();
		
		this.delta = 0;
		this.elapsed = 0;
		this.start = now;
		this.previous = now;
	}
	
	update() {
		const now = Time.now();
		
		this.delta = now - this.previous;
		this.elapsed = now - this.start;
		this.previous = now;
	}
	
	static now() {
		return Date.now() / 1000;
	}
}

class Particle {
	constructor(position, velocity = new Vector2, color = 'white', radius = 1, lifetime = 1, mass = 1) {
		this.position = position;
		this.velocity = velocity;
		this.color = color;
		this.radius = radius;
		this.lifetime = lifetime;
		this.mass = mass;
		
		this.isInCanvas = true;
		this.createdOn = Time.now();
	}
	
	update(time) {
		if (!this.getRemainingLifetime()) {
			return;
		}
		
		this.velocity.add(Particle.GRAVITATION.clone().multiplyScalar(this.mass));
		this.position.add(this.velocity.clone().multiplyScalar(time.delta));
	}
	
	render(canvas, context) {
		const remainingLifetime = this.getRemainingLifetime();
		
		if (!remainingLifetime) return;
		
		const radius = this.radius * remainingLifetime;
		
		context.globalAlpha = remainingLifetime;
		context.globalCompositeOperation = 'lighter';
		context.fillStyle = this.color;
		
		context.beginPath();
		context.arc(this.position.x, this.position.y, radius, 0, Math.PI * 2);
		context.fill();
	}
	
	getRemainingLifetime() {
		const elapsedLifetime = Time.now() - this.createdOn;
		return Math.max(0, this.lifetime - elapsedLifetime) / this.lifetime;
	}
}

Particle.GRAVITATION = new Vector2(0, 9.81);

class Trail extends Particle {
	constructor(childFactory, position, velocity = new Vector2, lifetime = 1, mass = 1) {
		super(position, velocity);
		
		this.childFactory = childFactory;
		this.children = [];
		this.lifetime = lifetime;
		this.mass = mass;
		
		this.isAlive = true;
	}
	
	update(time) {
		super.update(time);
		
		// Add a new child on every frame
		if (this.isAlive && this.getRemainingLifetime()) {
			this.children.push(this.childFactory(this));
		}
		
		// Remove particles that are dead
		this.children = this.children.filter(function(child) {
			if (child instanceof Trail) {
				return child.isAlive;
			}
			
			return child.getRemainingLifetime();
		});
		
		// Kill trail if all particles fade away
		if (!this.children.length) {
			this.isAlive = false;
		}
		
		// Update particles
		this.children.forEach(function(child) {
			child.update(time);
		});
	}
	
	render(canvas, context) {
		// Render all children
		this.children.forEach(function(child) {
			child.render(canvas, context);
		});
	}
}

class Rocket extends Trail {
	constructor(childFactory, explosionFactory, position, velocity = new Vector2) {
		super(childFactory, position, velocity);
		
		this.explosionFactory = explosionFactory;
		this.lifetime = 10;
	}
	
	update(time) {
		if (this.getRemainingLifetime() && this.velocity.y > 0) {
			this.explosionFactory(this);
			this.lifetime = 0;
		}
		
		super.update(time);
	}
}

const canvas = document.createElement('canvas');
const context = canvas.getContext('2d');
const time = new Time;
let rockets = [];

const getTrustParticleFactory = function(baseHue) {
	function getColor() {
		const hue = Math.floor(Math.random() * 15 + 30);
		return `hsl(${hue}, 100%, 75%`;
	}
	
	return function(parent) {
		const position = this.position.clone();
		const velocity = this.velocity.clone().multiplyScalar(-.1);
		velocity.x += (Math.random() - .5) * 8;
		const color = getColor();
		const radius = 1 + Math.random();
		const lifetime = .5 + Math.random() * .5;
		const mass = .01;
		
		return new Particle(position, velocity, color, radius, lifetime, mass);
	};
};

const getExplosionFactory = function(baseHue) {
	function getColor() {
		const hue = Math.floor(baseHue + Math.random() * 15) % 360;
		const lightness = Math.floor(Math.pow(Math.random(), 2) * 50 + 50);
		return `hsl(${hue}, 100%, ${lightness}%`;
	}
	
	function getChildFactory() {
		return function(parent) {
			const direction = Math.random() * Math.PI * 2;
			const force = 8;
			const velocity = new Vector2(Math.cos(direction) * force, Math.sin(direction) * force);
			const color = getColor();
			const radius = 1 + Math.random();
			const lifetime = 1;
			const mass = .1;

			return new Particle(parent.position.clone(), velocity, color, radius, lifetime, mass);
		};
	}
	
	function getTrail(position) {
		const direction = Math.random() * Math.PI * 2;
		const force = Math.random() * 128;
		const velocity = new Vector2(Math.cos(direction) * force, Math.sin(direction) * force);
		const lifetime = .5 + Math.random();
		const mass = .075;

		return new Trail(getChildFactory(), position, velocity, lifetime, mass);
	}
	
	return function(parent) {
		let trails = 32;
		while (trails--) {
			parent.children.push(getTrail(parent.position.clone()));
		}
	};
};

const addRocket = function() {
	const trustParticleFactory = getTrustParticleFactory();
	const explosionFactory = getExplosionFactory(Math.random() * 360);
	
	const position = new Vector2(Math.random() * canvas.width, canvas.height);
	const thrust = window.innerHeight * .75;
	const angle = Math.PI / -2 + (Math.random() - .5) * Math.PI / 8;
	const velocity = new Vector2(Math.cos(angle) * thrust, Math.sin(angle) * thrust);
	const lifetime = 3;
	
	rockets.push(new Rocket(trustParticleFactory, explosionFactory, position, velocity, lifetime));
	
	rockets = rockets.filter(function(rocket) {
		return rocket.isAlive;
	});
};

const render = function() {
	requestAnimationFrame(render);
	
	time.update();
	context.clearRect(0, 0, canvas.width, canvas.height);
	
	rockets.forEach(function(rocket) {
		rocket.update(time);
		rocket.render(canvas, context);
	});
};

const resize = function() {
	canvas.height = window.innerHeight;
	canvas.width = window.innerWidth;
};

canvas.onclick = addRocket;
document.body.appendChild(canvas);

window.onresize = resize;
resize();

setInterval(addRocket, 2000);
render();
            
          
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