Javascript CSS&；JS未正确加载

我有这些脚本，但它们没有正确加载。无法确定问题出在哪里，但CSS和JS看起来并没有被发现。原因

index.html

未按应有的方式呈现

我不确定我做错了什么或错过了什么。这可能是一件令人烦恼的小事

我觉得我已经用脚本和链接标签引用了css和js，但仍然没有得到渲染

我在下面列出了三个脚本。有什么想法吗

index.html

<script src="https://cdnjs.cloudflare.com/ajax/libs/jquery/3.3.1/jquery.min.js"></script>
<link rel="stylesheet" href="style.css">
<div class='moon'>
  <div class='crater1'></div>
  <div class='crater2'></div>
  <div class='crater3'></div>
</div>
<canvas id="canvas"></canvas>
<div id="sea"></div>
<div id="beach"></div>
<img src="https://dl.dropbox.com/s/2k0mtrxc2dqurmh/jumping.png" alt="jumping-people" id="people" />
<!--<img src="https://dl.dropbox.com/s/zoftkmdxyyqr8ce/belair.png" alt="jumping-people" id="car" />-->

<div id="merrywrap" class="merrywrap">
  <div class="giftbox">
    <div class="cover">
      <div></div>
    </div>
    <div class="box"></div>
  </div>
  <div class="icons">
    <div class="row"> 
      <span>H</span>
      <span>a</span>
      <span>p</span>
      <span>p</span>
      <span>y</span>
    </div>
    <div class="row"> 
      <span>B</span>
      <span>i</span>
      <span>r</span>
      <span>r</span>
      <span>t</span>
      <span>h</span>
      <span>d</span>
      <span>a</span>
      <span>y</span>

    </div>
    <div class="row"> 
      <span>D</span>
      <span>a</span>
      <span>v</span>
      <span>e</span>
      <!-- <span>t</span>
      <span>h</span>
      <span>e</span>
      <span>a</span>
      <span>r</span>
      <span>t</span> -->
    </div>
  </div>
</div>
<script src="style.js"></script>

<div id="video">
<!--<iframe width="255" height="155" src="https://www.youtube.com/embed/MrXBATtOtFY?controls=0&loop=1" frameborder="0" allowfullscreen></iframe>-->
</div>

script.js

window.requestAnimFrame = ( function() {
    return window.requestAnimationFrame ||
                window.webkitRequestAnimationFrame ||
                window.mozRequestAnimationFrame ||
                function( callback ) {
                    window.setTimeout( callback, 1000 / 60 );
                };
})();

var canvas = document.getElementById( 'canvas' ),
        ctx = canvas.getContext( '2d' ),
        // full screen dimensions
        cw = window.innerWidth,
        ch = window.innerHeight,
        // firework collection
        fireworks = [],
        // particle collection
        particles = [],
        
        hue = 120,
        
        limiterTotal = 5,
        limiterTick = 0,
        
        timerTotal = 80,
        timerTick = 0,
        mousedown = false,
        
        mx,
        
        my;
        
canvas.width = cw;
canvas.height = ch;

function random( min, max ) {
    return Math.random() * ( max - min ) + min;
}

// calculate the distance between two points
function calculateDistance( p1x, p1y, p2x, p2y ) {
    var xDistance = p1x - p2x,
            yDistance = p1y - p2y;
    return Math.sqrt( Math.pow( xDistance, 2 ) + Math.pow( yDistance, 2 ) );
}

// create firework
function Firework( sx, sy, tx, ty ) {
    // actual coordinates
    this.x = sx;
    this.y = sy;
    // starting coordinates
    this.sx = sx;
    this.sy = sy;
    // target coordinates
    this.tx = tx;
    this.ty = ty;
    // distance from starting point to target
    this.distanceToTarget = calculateDistance( sx, sy, tx, ty );
    this.distanceTraveled = 0;
    
    this.coordinates = [];
    this.coordinateCount = 3;
    // populate initial coordinate collection with the current coordinates
    while( this.coordinateCount-- ) {
        this.coordinates.push( [ this.x, this.y ] );
    }
    this.angle = Math.atan2( ty - sy, tx - sx );
    this.speed = 2;
    this.acceleration = 1.05;
    this.brightness = random( 50, 70 );
    // circle target indicator radius
    this.targetRadius = 1;
}

// update firework
Firework.prototype.update = function( index ) {
    // remove last item in coordinates array
    this.coordinates.pop();
    // add current coordinates to the start of the array
    this.coordinates.unshift( [ this.x, this.y ] );
    
    // cycle the circle target indicator radius
    if( this.targetRadius < 8 ) {
        this.targetRadius += 0.3;
    } else {
        this.targetRadius = 1;
    }
    
    // speed up the firework
    this.speed *= this.acceleration;
    
    // get the current velocities based on angle and speed
    var vx = Math.cos( this.angle ) * this.speed,
            vy = Math.sin( this.angle ) * this.speed;
    // how far will the firework have traveled with velocities applied?
    this.distanceTraveled = calculateDistance( this.sx, this.sy, this.x + vx, this.y + vy );
    
    // if the distance traveled, including velocities, is greater than the initial distance to the target, then the target has been reached
    if( this.distanceTraveled >= this.distanceToTarget ) {
        createParticles( this.tx, this.ty );
        // remove the firework, use the index passed into the update function to determine which to remove
        fireworks.splice( index, 1 );
    } else {
        // target not reached, keep traveling
        this.x += vx;
        this.y += vy;
    }
}

// draw firework
Firework.prototype.draw = function() {
    ctx.beginPath();
    // move to the last tracked coordinate in the set, then draw a line to the current x and y
    ctx.moveTo( this.coordinates[ this.coordinates.length - 1][ 0 ], this.coordinates[ this.coordinates.length - 1][ 1 ] );
    ctx.lineTo( this.x, this.y );
    ctx.strokeStyle = 'hsl(' + hue + ', 100%, ' + this.brightness + '%)';
    ctx.stroke();
    
    ctx.beginPath();
    // draw the target for this firework with a pulsing circle
    ctx.arc( this.tx, this.ty, this.targetRadius, 0, Math.PI * 2 );
    ctx.stroke();
}

// create particle
function Particle( x, y ) {
    this.x = x;
    this.y = y;
    // track the past coordinates of each particle to create a trail effect, increase the coordinate count to create more prominent trails
    this.coordinates = [];
    this.coordinateCount = 5;
    while( this.coordinateCount-- ) {
        this.coordinates.push( [ this.x, this.y ] );
    }
    // set a random angle in all possible directions, in radians
    this.angle = random( 0, Math.PI * 2 );
    this.speed = random( 1, 10 );
    // friction will slow the particle down
    this.friction = 0.95;
    // gravity will be applied and pull the particle down
    this.gravity = 1;
    // set the hue to a random number +-20 of the overall hue variable
    this.hue = random( hue - 20, hue + 20 );
    this.brightness = random( 50, 80 );
    this.alpha = 1;
    // set how fast the particle fades out
    this.decay = random( 0.015, 0.03 );
}

// update particle
Particle.prototype.update = function( index ) {
    // remove last item in coordinates array
    this.coordinates.pop();
    // add current coordinates to the start of the array
    this.coordinates.unshift( [ this.x, this.y ] );
    // slow down the particle
    this.speed *= this.friction;
    // apply velocity
    this.x += Math.cos( this.angle ) * this.speed;
    this.y += Math.sin( this.angle ) * this.speed + this.gravity;
    // fade out the particle
    this.alpha -= this.decay;
    
    // remove the particle once the alpha is low enough, based on the passed in index
    if( this.alpha <= this.decay ) {
        particles.splice( index, 1 );
    }
}

// draw particle
Particle.prototype.draw = function() {
    ctx. beginPath();
    // move to the last tracked coordinates in the set, then draw a line to the current x and y
    ctx.moveTo( this.coordinates[ this.coordinates.length - 1 ][ 0 ], this.coordinates[ this.coordinates.length - 1 ][ 1 ] );
    ctx.lineTo( this.x, this.y );
    ctx.strokeStyle = 'hsla(' + this.hue + ', 100%, ' + this.brightness + '%, ' + this.alpha + ')';
    ctx.stroke();
}

// create particle group/explosion
function createParticles( x, y ) {
    // increase the particle count for a bigger explosion, beware of the canvas performance hit with the increased particles though
    var particleCount = 30;
    while( particleCount-- ) {
        particles.push( new Particle( x, y ) );
    }
}

// main demo loop
function loop() {
    // this function will run endlessly with requestAnimationFrame
    requestAnimFrame( loop );
    
    // increase the hue to get different colored fireworks over time
    hue += 0.5;
    
    // normally, clearRect() would be used to clear the canvas
    // we want to create a trailing effect though
    // setting the composite operation to destination-out will allow us to clear the canvas at a specific opacity, rather than wiping it entirely
    ctx.globalCompositeOperation = 'destination-out';
    // decrease the alpha property to create more prominent trails
    ctx.fillStyle = 'rgba(0, 0, 0, 0.5)';
    ctx.fillRect( 0, 0, cw, ch );
    // change the composite operation back to our main mode
    // lighter creates bright highlight points as the fireworks and particles overlap each other
    ctx.globalCompositeOperation = 'lighter';
    
    // loop over each firework, draw it, update it
    var i = fireworks.length;
    while( i-- ) {
        fireworks[ i ].draw();
        fireworks[ i ].update( i );
    }
    
    // loop over each particle, draw it, update it
    var i = particles.length;
    while( i-- ) {
        particles[ i ].draw();
        particles[ i ].update( i );
    }
    
    // launch fireworks automatically to random coordinates, when the mouse isn't down
    if( timerTick >= timerTotal ) {
        if( !mousedown ) {
            // start the firework at the bottom middle of the screen, then set the random target coordinates, the random y coordinates will be set within the range of the top half of the screen
            fireworks.push( new Firework( cw / 2, ch, random( 0, cw ), random( 0, ch / 2 ) ) );
            timerTick = 0;
        }
    } else {
        timerTick++;
    }
    
    // limit the rate at which fireworks get launched when mouse is down
    if( limiterTick >= limiterTotal ) {
        if( mousedown ) {
            // start the firework at the bottom middle of the screen, then set the current mouse coordinates as the target
            fireworks.push( new Firework( cw / 2, ch, mx, my ) );
            limiterTick = 0;
        }
    } else {
        limiterTick++;
    }
}

window.onload=function(){
  var merrywrap=document.getElementById("merrywrap");
  var box=merrywrap.getElementsByClassName("giftbox")[0];
  var step=1;
  var stepMinutes=[2000,2000,1000,1000];
  function init(){
          box.addEventListener("click",openBox,false);
  }
  function stepClass(step){
    merrywrap.className='merrywrap';
    merrywrap.className='merrywrap step-'+step;
  }
  function openBox(){
    if(step===1){
      box.removeEventListener("click",openBox,false); 
    }  
    stepClass(step); 
    if(step===3){ 
    } 
    if(step===4){
        reveal();
       return;
    }     
    setTimeout(openBox,stepMinutes[step-1]);
    step++;  
  }
   
  init();
 
}

function reveal() {
  document.querySelector('.merrywrap').style.backgroundColor = 'transparent';
  
  loop();
  
  var w, h;
  if(window.innerWidth >= 1000) {
    w = 295; h = 185;
  }
  else {
    w = 255; h = 155;
  }
  
  var ifrm = document.createElement("iframe");
        ifrm.setAttribute("src", "https://www.youtube.com/embed/MrXBATtOtFY?controls=0&loop=1&autoplay=1");
        //ifrm.style.width = `${w}px`;
        //ifrm.style.height = `${h}px`;
        ifrm.style.border = 'none';
        document.querySelector('#video').appendChild(ifrm);
}

window.requestAnimFrame=（函数（）{
return window.requestAnimationFrame||
window.webkitRequestAnimationFrame||
window.mozRequestAnimationFrame||
函数（回调）{
设置超时（回调，1000/60）；
};
})();
var canvas=document.getElementById（'canvas'），
ctx=canvas.getContext（'2d'），
//全屏尺寸
cw=窗宽，
ch=窗内高度，
//烟花收藏
烟花=[]，
//粒子收集
粒子=[]，
色调=120，
限制器总数=5，
利米蒂克=0，
timerTotal=80，
timerTick=0，
mousedown=false，
mx，
我的；
canvas.width=cw；
canvas.height=ch；
随机函数（最小值、最大值）{
返回Math.random（）*（max-min）+min；
}
//计算两点之间的距离
函数计算距离（p1x，p1y，p2x，p2y）{
变量xDistance=p1x-p2x，
Y距离=p1y-p2y；
返回Math.sqrt（Math.pow（xDistance，2）+Math.pow（yddistance，2））；
}
//燃放烟花
功能烟花（sx、sy、tx、ty）{
//实际坐标
这是x=sx；
y=sy；
//起始坐标
this.sx=sx；
this.sy=sy；
//目标坐标
this.tx=tx；
this.ty=ty；
//起点到目标的距离
this.distanceToTarget=计算距离（sx、sy、tx、ty）；
此.distance=0；
this.coordinates=[]；
此.coordinateCount=3；
//用当前坐标填充初始坐标集合
而（这个协调帐户-）{
this.coordinates.push（[this.x，this.y]）；
}
this.angle=Math.atan2（ty-sy，tx-sx）；
这个速度=2；
该加速度=1.05；
该亮度=随机（50,70）；
//圆目标指示器半径
此参数为1.targetRadius；
}
//更新烟花
Firework.prototype.update=函数（索引）{
//删除坐标数组中的最后一项
this.coordinates.pop（）；
//将当前坐标添加到数组的开头
this.coordinates.unshift（[this.x，this.y]）；
//循环旋转目标指示器半径
如果（该目标半径小于8）{
这是0.targetRadius+=0.3；
}否则{
此参数为1.targetRadius；
}
//加快烟花的速度
此速度*=此加速度；
//根据角度和速度获取当前速度
var vx=数学cos（this.angle）*this.speed，
vy=数学sin（this.angle）*this.speed；
//在施加速度的情况下，烟花会传播多远？
this.distance旅行=计算距离（this.sx，this.sy，this.x+vx，this.y+vy）；
//如果移动的距离（包括速度）大于到目标的初始距离，则已到达目标
如果（this.distance>=this.distance目标）{
创建粒子（this.tx，this.ty）；
//移除焰火，使用传递到update函数的索引来确定要移除的
烟花.拼接（索引1）；
}否则{
//未达到目标，继续行驶
这个.x+=vx；
这个.y+=vy；
}
}
//燃放烟花
Firework.prototype.draw=函数（）{
ctx.beginPath（）；
//移动到集合中最后一个跟踪的坐标，然后绘制一条到当前x和y的直线
ctx.moveTo（this.coordinates[this.coordinates.length-1][0]，this.coordinates[this.coordinates.length-1][1]）；
ctx.lineTo（this.x，this.y）；
ctx.strokeStyle='hsl（'+hue+'，100%，'+this.brightness+'%）；
ctx.stroke（）；
ctx.beginPath（）；
//用一个脉冲圆圈画出这个烟花的目标
ctx.arc（this.tx，this.ty，this.targetRadius，0，Math.PI*2）；
ctx.stroke（）；
}
//创建粒子
函数粒子（x，y）{
这个.x=x；
这个。y=y；
//跟踪每个粒子的过去坐标以创建轨迹效果，增加坐标计数以创建更显著的轨迹
this.coordinates=[]；
此.coordinateCount=5；
而（这个协调帐户-）{
this.coordinates.push（[this.x，this.y]）；
}
//以弧度为单位，在所有可能的方向上设置一个随机角度
this.angle=random（0，Math.PI*2）；
该速度=随机（1,10）；
//摩擦力会使粒子减速
该摩擦系数=0.95；
//将应用重力并将粒子向下拉
这是重力=1；
//将色调设置为总色调变量的随机数+-20
this.hue=随机（色调-20，色调+20）；
这个。亮度=随机（50,80）；
这个α=1；
//设置粒子淡出的速度
该衰减=随机（0.015,0.03）；
}
//更新粒子
Particle.prototype.update=函数（索引）{
//删除坐标数组中的最后一项
this.coordinates.pop（）；
//将当前坐标添加到数组的开头
this.coordinates.unshift（[this.x，this.y]）；
//减慢粒子的速度
这个速度*=这个摩擦力；
//应用速度
this.x+=Math.cos（this.angle）*this.speed；
this.y+=Math.sin（this.angle）*this.speed+this.gravity；
//淡出粒子
这个α-=这个衰变；
window.requestAnimFrame = ( function() {
    return window.requestAnimationFrame ||
                window.webkitRequestAnimationFrame ||
                window.mozRequestAnimationFrame ||
                function( callback ) {
                    window.setTimeout( callback, 1000 / 60 );
                };
})();

var canvas = document.getElementById( 'canvas' ),
        ctx = canvas.getContext( '2d' ),
        // full screen dimensions
        cw = window.innerWidth,
        ch = window.innerHeight,
        // firework collection
        fireworks = [],
        // particle collection
        particles = [],
        
        hue = 120,
        
        limiterTotal = 5,
        limiterTick = 0,
        
        timerTotal = 80,
        timerTick = 0,
        mousedown = false,
        
        mx,
        
        my;
        
canvas.width = cw;
canvas.height = ch;

function random( min, max ) {
    return Math.random() * ( max - min ) + min;
}

// calculate the distance between two points
function calculateDistance( p1x, p1y, p2x, p2y ) {
    var xDistance = p1x - p2x,
            yDistance = p1y - p2y;
    return Math.sqrt( Math.pow( xDistance, 2 ) + Math.pow( yDistance, 2 ) );
}

// create firework
function Firework( sx, sy, tx, ty ) {
    // actual coordinates
    this.x = sx;
    this.y = sy;
    // starting coordinates
    this.sx = sx;
    this.sy = sy;
    // target coordinates
    this.tx = tx;
    this.ty = ty;
    // distance from starting point to target
    this.distanceToTarget = calculateDistance( sx, sy, tx, ty );
    this.distanceTraveled = 0;
    
    this.coordinates = [];
    this.coordinateCount = 3;
    // populate initial coordinate collection with the current coordinates
    while( this.coordinateCount-- ) {
        this.coordinates.push( [ this.x, this.y ] );
    }
    this.angle = Math.atan2( ty - sy, tx - sx );
    this.speed = 2;
    this.acceleration = 1.05;
    this.brightness = random( 50, 70 );
    // circle target indicator radius
    this.targetRadius = 1;
}

// update firework
Firework.prototype.update = function( index ) {
    // remove last item in coordinates array
    this.coordinates.pop();
    // add current coordinates to the start of the array
    this.coordinates.unshift( [ this.x, this.y ] );
    
    // cycle the circle target indicator radius
    if( this.targetRadius < 8 ) {
        this.targetRadius += 0.3;
    } else {
        this.targetRadius = 1;
    }
    
    // speed up the firework
    this.speed *= this.acceleration;
    
    // get the current velocities based on angle and speed
    var vx = Math.cos( this.angle ) * this.speed,
            vy = Math.sin( this.angle ) * this.speed;
    // how far will the firework have traveled with velocities applied?
    this.distanceTraveled = calculateDistance( this.sx, this.sy, this.x + vx, this.y + vy );
    
    // if the distance traveled, including velocities, is greater than the initial distance to the target, then the target has been reached
    if( this.distanceTraveled >= this.distanceToTarget ) {
        createParticles( this.tx, this.ty );
        // remove the firework, use the index passed into the update function to determine which to remove
        fireworks.splice( index, 1 );
    } else {
        // target not reached, keep traveling
        this.x += vx;
        this.y += vy;
    }
}

// draw firework
Firework.prototype.draw = function() {
    ctx.beginPath();
    // move to the last tracked coordinate in the set, then draw a line to the current x and y
    ctx.moveTo( this.coordinates[ this.coordinates.length - 1][ 0 ], this.coordinates[ this.coordinates.length - 1][ 1 ] );
    ctx.lineTo( this.x, this.y );
    ctx.strokeStyle = 'hsl(' + hue + ', 100%, ' + this.brightness + '%)';
    ctx.stroke();
    
    ctx.beginPath();
    // draw the target for this firework with a pulsing circle
    ctx.arc( this.tx, this.ty, this.targetRadius, 0, Math.PI * 2 );
    ctx.stroke();
}

// create particle
function Particle( x, y ) {
    this.x = x;
    this.y = y;
    // track the past coordinates of each particle to create a trail effect, increase the coordinate count to create more prominent trails
    this.coordinates = [];
    this.coordinateCount = 5;
    while( this.coordinateCount-- ) {
        this.coordinates.push( [ this.x, this.y ] );
    }
    // set a random angle in all possible directions, in radians
    this.angle = random( 0, Math.PI * 2 );
    this.speed = random( 1, 10 );
    // friction will slow the particle down
    this.friction = 0.95;
    // gravity will be applied and pull the particle down
    this.gravity = 1;
    // set the hue to a random number +-20 of the overall hue variable
    this.hue = random( hue - 20, hue + 20 );
    this.brightness = random( 50, 80 );
    this.alpha = 1;
    // set how fast the particle fades out
    this.decay = random( 0.015, 0.03 );
}

// update particle
Particle.prototype.update = function( index ) {
    // remove last item in coordinates array
    this.coordinates.pop();
    // add current coordinates to the start of the array
    this.coordinates.unshift( [ this.x, this.y ] );
    // slow down the particle
    this.speed *= this.friction;
    // apply velocity
    this.x += Math.cos( this.angle ) * this.speed;
    this.y += Math.sin( this.angle ) * this.speed + this.gravity;
    // fade out the particle
    this.alpha -= this.decay;
    
    // remove the particle once the alpha is low enough, based on the passed in index
    if( this.alpha <= this.decay ) {
        particles.splice( index, 1 );
    }
}

// draw particle
Particle.prototype.draw = function() {
    ctx. beginPath();
    // move to the last tracked coordinates in the set, then draw a line to the current x and y
    ctx.moveTo( this.coordinates[ this.coordinates.length - 1 ][ 0 ], this.coordinates[ this.coordinates.length - 1 ][ 1 ] );
    ctx.lineTo( this.x, this.y );
    ctx.strokeStyle = 'hsla(' + this.hue + ', 100%, ' + this.brightness + '%, ' + this.alpha + ')';
    ctx.stroke();
}

// create particle group/explosion
function createParticles( x, y ) {
    // increase the particle count for a bigger explosion, beware of the canvas performance hit with the increased particles though
    var particleCount = 30;
    while( particleCount-- ) {
        particles.push( new Particle( x, y ) );
    }
}

// main demo loop
function loop() {
    // this function will run endlessly with requestAnimationFrame
    requestAnimFrame( loop );
    
    // increase the hue to get different colored fireworks over time
    hue += 0.5;
    
    // normally, clearRect() would be used to clear the canvas
    // we want to create a trailing effect though
    // setting the composite operation to destination-out will allow us to clear the canvas at a specific opacity, rather than wiping it entirely
    ctx.globalCompositeOperation = 'destination-out';
    // decrease the alpha property to create more prominent trails
    ctx.fillStyle = 'rgba(0, 0, 0, 0.5)';
    ctx.fillRect( 0, 0, cw, ch );
    // change the composite operation back to our main mode
    // lighter creates bright highlight points as the fireworks and particles overlap each other
    ctx.globalCompositeOperation = 'lighter';
    
    // loop over each firework, draw it, update it
    var i = fireworks.length;
    while( i-- ) {
        fireworks[ i ].draw();
        fireworks[ i ].update( i );
    }
    
    // loop over each particle, draw it, update it
    var i = particles.length;
    while( i-- ) {
        particles[ i ].draw();
        particles[ i ].update( i );
    }
    
    // launch fireworks automatically to random coordinates, when the mouse isn't down
    if( timerTick >= timerTotal ) {
        if( !mousedown ) {
            // start the firework at the bottom middle of the screen, then set the random target coordinates, the random y coordinates will be set within the range of the top half of the screen
            fireworks.push( new Firework( cw / 2, ch, random( 0, cw ), random( 0, ch / 2 ) ) );
            timerTick = 0;
        }
    } else {
        timerTick++;
    }
    
    // limit the rate at which fireworks get launched when mouse is down
    if( limiterTick >= limiterTotal ) {
        if( mousedown ) {
            // start the firework at the bottom middle of the screen, then set the current mouse coordinates as the target
            fireworks.push( new Firework( cw / 2, ch, mx, my ) );
            limiterTick = 0;
        }
    } else {
        limiterTick++;
    }
}

window.onload=function(){
  var merrywrap=document.getElementById("merrywrap");
  var box=merrywrap.getElementsByClassName("giftbox")[0];
  var step=1;
  var stepMinutes=[2000,2000,1000,1000];
  function init(){
          box.addEventListener("click",openBox,false);
  }
  function stepClass(step){
    merrywrap.className='merrywrap';
    merrywrap.className='merrywrap step-'+step;
  }
  function openBox(){
    if(step===1){
      box.removeEventListener("click",openBox,false); 
    }  
    stepClass(step); 
    if(step===3){ 
    } 
    if(step===4){
        reveal();
       return;
    }     
    setTimeout(openBox,stepMinutes[step-1]);
    step++;  
  }
   
  init();
 
}

function reveal() {
  document.querySelector('.merrywrap').style.backgroundColor = 'transparent';
  
  loop();
  
  var w, h;
  if(window.innerWidth >= 1000) {
    w = 295; h = 185;
  }
  else {
    w = 255; h = 155;
  }
  
  var ifrm = document.createElement("iframe");
        ifrm.setAttribute("src", "https://www.youtube.com/embed/MrXBATtOtFY?controls=0&loop=1&autoplay=1");
        //ifrm.style.width = `${w}px`;
        //ifrm.style.height = `${h}px`;
        ifrm.style.border = 'none';
        document.querySelector('#video').appendChild(ifrm);
}

<script src="style.js"></script>

<script src="script.js"></script>