<video poster="https://s3-us-west-2.amazonaws.com/s.cdpn.io/4273/polina.jpg" id="bgvid" playsinline autoplay muted loop>
  <!-- 
- Video needs to be muted, since Chrome 66+ will not autoplay video with sound.
WCAG general accessibility recommendation is that media such as background video play through only once. Loop turned on for the purposes of illustration; if removed, the end of the video will fade in the same way created by pressing the "Pause" button  -->
  <source src="http://thenewcode.com/assets/videos/polina.webm" type="video/webm">
  <source src="http://thenewcode.com/assets/videos/polina.mp4" type="video/mp4">

</video>
<div style="url('https://cdn.matteobruni.it/images/particles/background.jpg')">
  <div id="tsparticles"></div>
</div>
body {
  margin: 0;
  background: #000;
}
video {
  position: fixed;
  top: 50%;
  left: 50%;
  min-width: 100%;
  min-height: 100%;
  width: auto;
  height: auto;
  z-index: -100;
  transform: translateX(-50%) translateY(-50%);
  background: url("//demosthenes.info/assets/images/polina.jpg") no-repeat;
  background-size: cover;
  transition: 1s opacity;
}
.stopfade {
  opacity: 0.5;
}

@media screen and (max-width: 500px) {
  div {
    width: 70%;
  }
}
@media screen and (max-device-width: 800px) {
  html {
    background: url(https://thenewcode.com/assets/images/polina.jpg) #000
      no-repeat center center fixed;
  }
  #bgvid {
    display: none;
  }
}

#tsparticles {
  position: absolute;
  width: 100%;
  height: 100%;
  z-index: 100;
}
tsParticles.load("tsparticles", {
  fpsLimit: 60,
  particles: {
    number: {
      value: 100,
      density: {
        enable: true,
        value_area: 800
      }
    },
    color: {
      value: "#ffffff"
    },
    shape: {
      type: "circle"
    },
    opacity: {
      value: 1,
      random: false
    },
    size: {
      value: 50,
      random: true
    },
    lineLinked: {
      enable: true,
      distance: 150,
      color: "#ffffff",
      opacity: 1,
      width: 1
    },
    move: {
      enable: true,
      speed: 2,
      direction: "none",
      random: false,
      straight: false,
      out_mode: "out"
    }
  },
  interactivity: {
    detect_on: "window",
    events: {
      onHover: {
        enable: true,
        mode: "bubble"
      },
      onClick: {
        enable: true,
        mode: "push"
      },
      resize: true
    },
    modes: {
      grab: {
        distance: 400,
        lineLinked: {
          opacity: 1
        }
      },
      bubble: {
        distance: 400,
        size: 200,
        duration: 2,
        opacity: 1,
        speed: 3
      },
      repulse: {
        distance: 200
      },
      push: {
        particles_nb: 4
      },
      remove: {
        particles_nb: 2
      }
    }
  },
  backgroundMask: {
    enable: true,
    cover: {
      value: {
        r: 255,
        g: 255,
        b: 255
      }
    }
  },
  retina_detect: true
});

/*
var vid = document.getElementById("bgvid");

if (window.matchMedia('(prefers-reduced-motion)').matches) {
    vid.removeAttribute("autoplay");
    vid.pause();
    pauseButton.innerHTML = "Paused";
}

function vidFade() {
  vid.classList.add("stopfade");
}

vid.addEventListener('ended', function()
{
// only functional if "loop" is removed 
vid.pause();
// to capture IE10
vidFade();
}); 
*/

External CSS

This Pen doesn't use any external CSS resources.

External JavaScript

  1. https://cdnjs.cloudflare.com/ajax/libs/jquery/2.1.3/jquery.min.js
  2. https://cdn.jsdelivr.net/npm/tsparticles@1.18.3/dist/tsparticles.min.js