title: I am unable to make my websites banner responsive for every device example mobiles and different computer screens
body: <p>sina121.com/hypercore/index.html
  This is the link of my website.
  I want to make the banner responsive like for every device such as mobiles and different laptop screens. I have tried almost everything.
  I am confused how can I use media query to make it work.</p>
  
  <pre><code>CSS
  .back{
      width: 100%;
      position: relative;
      background:url(images/1.png) no-repeat; min-height:500px;
      -webkit-animation-name: example; /* Chrome, Safari, Opera */
      -webkit-animation-duration:2.5s ; /* Chrome, Safari, Opera */
      -moz-animation-name: eaxmple;
      -moz-animation-duration:2.5s;
      -moz-animation-iteration-count:infinite;
       animation-name: example;
        animation:example 2.5s;
            animation-iteration-count: infinite;
         background-size: cover;   
  /*    animation-duration: 2s;*/
  /*z-index: 0;*/
  }
  
  /* Chrome, Safari, Opera */
  
  @-webkit-keyframes example {
  
      0%   {background:url(images/1.png) no-repeat;  
         min-height:500px;
        -webkit-background-size: cover;
  -moz-background-size: auto 100%
    -o-background-size: cover;
    background-size: cover;}
      25%   {background:url(images/2.png) no-repeat;
         min-height:500px;
        -webkit-background-size: cover;
    -moz-background-size: cover;
    -o-background-size: cover;
    background-size: cover;}
      50%   {background:url(images/3.png) no-repeat;
         min-height:500px;
        -webkit-background-size: cover;
    -moz-background-size: cover;
    -o-background-size: cover;
    background-size: cover;}
      75%   {background:url(images/2.png) no-repeat;
         min-height:500px;
        -webkit-background-size: cover;
    -moz-background-size: cover;
    -o-background-size: cover;
    background-size: cover;}
      100%   {background:url(images/1.png) no-repeat;
         min-height:500px;
        -webkit-background-size: cover;
    -moz-background-size: cover;
    -o-background-size: cover;
    background-size: cover;}
  }
  .cloud {
    max-width: 100%;
     height: auto;
    -webkit-animation: clouds 0.01s infinite ;
    -moz-animation: clouds 0.01s infinite ;
    -ms-animation: clouds 0.01s infinite ;
    -o-animation: clouds 0.01s infinite ;
    animation: clouds 0.01s infinite ;
    -moz-border-radius: 10px;
    -webkit-border-radius: 10px;
    border-radius: 10px;
    position: absolute;
    margin: 5px 0 0 0;
    width: 54px;
    height: 10px;
    background: #f7e7eb;
    z-index: -1;
  }
  .cloud.tiny {
    -moz-transform: scale(0.5, 0.5);
    -ms-transform: scale(0.5, 0.5);
    -webkit-transform: scale(0.5, 0.5);
    transform: scale(0.5, 0.5);
  }
  .cloud.small {
    -moz-transform: scale(1, 1);
    -ms-transform: scale(1, 1);
    -webkit-transform: scale(1, 1);
    transform: scale(1, 1);
  }
  .cloud.normal {
    -moz-transform: scale(2, 2);
    -ms-transform: scale(2, 2)
    -webkit-transform: scale(2, 2);
    transform: scale(2, 2);
  }
  .cloud.large {
    -moz-transform: scale(4, 4);
    -ms-transform: scale(4, 4);
    -webkit-transform: scale(4, 4);
    transform: scale(4, 4);
  }
  .cloud div {
    -moz-box-shadow: inset -2px -3px 0 0 #f7e7eb;
    -webkit-box-shadow: inset -2px -3px 0 0 #f7e7eb;
    box-shadow: inset -2px -3px 0 0 #f7e7eb;
    position: absolute;
    border-radius: 50%;
    width: 12px;
    height: 12px;
    left: -3px;
    bottom: 0;
    background: #fafbf0;
    z-index: 10;
  }
  .cloud div:first-child + div {
    -moz-transform: scale(1.6, 1.6);
    -ms-transform: scale(1.6, 1.6);
    -webkit-transform: scale(1.6, 1.6);
    transform: scale(1.6, 1.6);
    margin: 0 0 4px 13px;
    z-index: 9;
  }
  .cloud div:first-child + div + div {
    -moz-transform: scale(2.4, 2.4);
    -ms-transform: scale(2.4, 2.4);
    -webkit-transform: scale(2.4, 2.4);
    transform: scale(2.4, 2.4);
    margin: 0 0 9px 32px;
    z-index: 8;
  }
  .cloud div:first-child + div + div + div {
    -moz-transform: scale(1.3, 1.3);
    -ms-transform: scale(1.3, 1.3);
    -webkit-transform: scale(1.3, 1.3);
    transform: scale(1.3, 1.3);
    margin: 0 0 2px 50px;
    z-index: 7;
  }
  @-webkit-keyframes clouds {
    0% {
      top: 0px;
    }
   100% {
      top:  500px ;
    }
       0% {opacity:1;}
       50%{opacity: 1;}
     75% {opacity:0.2;}
     100% {opacity:0;}
  }
  
  @-moz-keyframes clouds {
    0% {
       top: 0px;
    }
    100% {
      top: 500px;
    }
       0% {opacity:1;}
       50%{opacity: 1;}
     75% {opacity:0.5;}
     100% {opacity:0;}
  }
  @-ms-keyframes clouds {
    0% {
      top: 0px;
    }
    100% {
      top:500px;
    }
          0% {opacity:1;}
          50%{opacity: 1;}
     75% {opacity:0.5;}
     100% {opacity:0;}
  }
  @keyframes clouds {
    0% {
      top:0px;
    }
    100% {
      top: 500px;
    }
       0% {opacity:1;}
       50%{opacity: 1;}
     75% {opacity:0.5;}
     100% {opacity:0;}
  }
  .cloud-1 {
    -webkit-animation-duration: 20s;
    -moz-animation-duration: 20s;
    -ms-animation-duration: 20s;
    -o-animation-duration: 20s;
    animation-duration: 20s;
    margin-left: 20%;
  }
  
  .cloud-2 {
    -webkit-animation-duration: 100s;
    -moz-animation-duration: 100s;
    -ms-animation-duration: 100s;
    -o-animation-duration: 100s;
    animation-duration: 100s;
    margin-left: 90%;
  }
  
  .cloud-3 {
    -webkit-animation-duration: 75s;
    -moz-animation-duration: 75s;
    -ms-animation-duration: 75s;
    -o-animation-duration: 75s;
    animation-duration: 75s;
    margin-left: 50%;
  }
  
  .cloud-4 {
    -webkit-animation-duration: 180s;
    -moz-animation-duration: 180s;
    -ms-animation-duration: 180s;
    -o-animation-duration: 180s;
    animation-duration: 180s;
    margin-left: 43%;
  }
  
  .cloud-5 {
    -webkit-animation-duration: 25s;
    -moz-animation-duration: 25s;
    -ms-animation-duration: 25s;
    -o-animation-duration: 25s;
    animation-duration: 25s;
    margin-left: 83%;
  }
  
  .cloud-6 {
    -webkit-animation-duration: 80s;
    -moz-animation-duration: 80s;
    -ms-animation-duration: 80s;
    -o-animation-duration: 80s;
    animation-duration: 80s;
    margin-left: 73%;
  }
  
  .cloud-7 {
    -webkit-animation-duration: 109s;
    -moz-animation-duration: 109s;
    -ms-animation-duration: 109s;
    -o-animation-duration: 109s;
    animation-duration: 109s;
    margin-left: 69%;
  }
  
  .cloud-8 {
    -webkit-animation-duration: 150s;
    -moz-animation-duration: 150s;
    -ms-animation-duration: 150s;
    -o-animation-duration: 150s;
    animation-duration: 150s;
    margin-left: 80%;
  }
  
  .cloud-9 {
    -webkit-animation-duration: 101s;
    -moz-animation-duration: 101s;
    -ms-animation-duration: 101s;
    -o-animation-duration: 101s;
    animation-duration: 101s;
    margin-left: 10%;
  }
  
  .cloud-10 {
    -webkit-animation-duration: 126s;
    -moz-animation-duration: 126s;
    -ms-animation-duration: 126s;
    -o-animation-duration: 126s;
    animation-duration: 126s;
    margin-left: 14%;
  }
  
  .cloud-11 {
    -webkit-animation-duration: 96s;
    -moz-animation-duration: 96s;
    -ms-animation-duration: 96s;
    -o-animation-duration: 96s;
    animation-duration: 96s;
    margin-left: 73%;
  }
  
  .cloud-12 {
    -webkit-animation-duration: 150s;
    -moz-animation-duration: 150s;
    -ms-animation-duration: 150s;
    -o-animation-duration: 150s;
    animation-duration: 150s;
    margin-left: 51%;
  }
  
  Html
  &lt;div class="back"&gt;
          &lt;div&gt;&lt;/div&gt;&lt;div&gt;&lt;/div&gt;&lt;div&gt;&lt;/div&gt;&lt;div&gt;&lt;/div&gt;
    &lt;/div&gt;
    &lt;div&gt;
    &lt;div class="cloud large cloud-1"&gt;
    &lt;div&gt;&lt;/div&gt;&lt;div&gt;&lt;/div&gt;&lt;div&gt;&lt;/div&gt;&lt;div&gt;&lt;/div&gt;
  &lt;/div&gt;
  &lt;div class="cloud normal cloud-2"&gt;
    &lt;div&gt;&lt;/div&gt;&lt;div&gt;&lt;/div&gt;&lt;div&gt;&lt;/div&gt;&lt;div&gt;&lt;/div&gt;
  &lt;/div&gt;
  &lt;div class="cloud small cloud-3"&gt;
    &lt;div&gt;&lt;/div&gt;&lt;div&gt;&lt;/div&gt;&lt;div&gt;&lt;/div&gt;&lt;div&gt;&lt;/div&gt;
  &lt;/div&gt;
  &lt;div class="cloud tiny cloud-4"&gt;
    &lt;div&gt;&lt;/div&gt;&lt;div&gt;&lt;/div&gt;&lt;div&gt;&lt;/div&gt;&lt;div&gt;&lt;/div&gt;
  &lt;/div&gt;
  &lt;div class="cloud large cloud-5"&gt;
    &lt;div&gt;&lt;/div&gt;&lt;div&gt;&lt;/div&gt;&lt;div&gt;&lt;/div&gt;&lt;div&gt;&lt;/div&gt;
  &lt;/div&gt;
  &lt;div class="cloud normal cloud-6"&gt;
    &lt;div&gt;&lt;/div&gt;&lt;div&gt;&lt;/div&gt;&lt;div&gt;&lt;/div&gt;&lt;div&gt;&lt;/div&gt;
  &lt;/div&gt;
  &lt;div class="cloud small cloud-7"&gt;
    &lt;div&gt;&lt;/div&gt;&lt;div&gt;&lt;/div&gt;&lt;div&gt;&lt;/div&gt;&lt;div&gt;&lt;/div&gt;
  &lt;/div&gt;
  &lt;div class="cloud tiny cloud-8"&gt;
    &lt;div&gt;&lt;/div&gt;&lt;div&gt;&lt;/div&gt;&lt;div&gt;&lt;/div&gt;&lt;div&gt;&lt;/div&gt;
  &lt;/div&gt;
  &lt;div class="cloud small cloud-9"&gt;
    &lt;div&gt;&lt;/div&gt;&lt;div&gt;&lt;/div&gt;&lt;div&gt;&lt;/div&gt;&lt;div&gt;&lt;/div&gt;
  &lt;/div&gt;
  &lt;div class="cloud normal cloud-10"&gt;
    &lt;div&gt;&lt;/div&gt;&lt;div&gt;&lt;/div&gt;&lt;div&gt;&lt;/div&gt;&lt;div&gt;&lt;/div&gt;
  &lt;/div&gt;
  &lt;div class="cloud tiny cloud-11"&gt;
    &lt;div&gt;&lt;/div&gt;&lt;div&gt;&lt;/div&gt;&lt;div&gt;&lt;/div&gt;&lt;div&gt;&lt;/div&gt;
  &lt;/div&gt;
  &lt;div class="cloud small cloud-12"&gt;
    &lt;div&gt;&lt;/div&gt;&lt;div&gt;&lt;/div&gt;&lt;div&gt;&lt;/div&gt;&lt;div&gt;&lt;/div&gt;
  &lt;/div&gt;
  &lt;/div&gt;
  </code></pre>