<!-- 
I like the folder animation in this:
https://dribbble.com/shots/1752769-Google-Design?list=shots&sort=popular&timeframe=week&offset=57
so here ya go -->

<div class="page">
  
  <div class="folder">
    <span class="folder-tab"></span>
    <div class="folder-icn">
      <div class="downloading">
        <span class="custom-arrow"></span>
      </div>
      <div class="bar"></div>
    </div>
  </div>
</div>

@import "compass/css3";

* { box-sizing: border-box; }
html, body { 
  margin: 0; padding: 0; 
  position: relative; 
  width: 100%;
  height: 100%;
  background-color: #2196f3;
}
.page {
  height: 100%;
  @include display-flex;
  @include align-items(center);
  -moz-box-align: center;
  -webkit-box-pack: center;
  -webkit-justify-content: center;
  justify-content: center;
  -moz-box-pack: center;
  -ms-flex-pack: center;
}

.folder {
  background-color: #d3eafd;
  position: relative;
  width: 92px;
  height: 64px;
  display: block;
  border-top-right-radius: 8px;
  border-bottom-right-radius: 8px;
  border-bottom-left-radius: 8px;
}
  .folder-tab {
    position: absolute;
    height: 10px;
    left: 0;
    bottom: 100%;
    display: block;
    width: 40%;
    border-top-left-radius: 8px;
    background-color: inherit;
    &:after {
      content: '';
      position: absolute;
      display: block;
      top: 0;
      left: calc(100% - 10px);
      border-bottom: 10px solid #d3eafd;
      border-left: 10px solid transparent;
      border-right: 10px solid transparent;
    }
  }

  .folder-icn {
    padding-top: 12px;
    width: 100%;
    height: 100%;
    display: block;
  }
  .downloading {
    width: 30px;
    height: 32px;
    margin: 0 auto;
    position: relative;
    overflow: hidden;
  }
    .custom-arrow {
      width: 14px;
      height: 14px;
      position: absolute;
      top: 0;
      left: 50%;
      margin-left: -7px;
      background-color: #fff;
      
      -webkit-animation-name: downloading;
      -webkit-animation-duration: 1.5s;
      -webkit-animation-iteration-count: infinite;
      animation-name: downloading;
      animation-duration: 1.5s;
      animation-iteration-count: infinite;
      
      &:after {
        content: ''; position: absolute; display: block;
        top: 100%;
        left: -9px;
        border-top: 15px solid #fff;
        border-left: 16px solid transparent;
        border-right: 16px solid transparent;
      }
    }
  .bar {
    width: 30px;
    height: 4px;
    background-color: #fff;
    margin: 0 auto;
  }

@-webkit-keyframes downloading {
  0% {
    top: 0;
    opacity: 1;
  }
  50% {
    top: 110%;
    opacity: 0;
  }
  52% {
    top: -110%;
    opacity: 0;
  } 
  100% {
    top: 0;
    opacity: 1;
  }
}
@keyframes downloading {
  0% {
    top: 0;
    opacity: 1;
  }
  50% {
    top: 110%;
    opacity: 0;
  }
  52% {
    top: -110%;
    opacity: 0;
  } 
  100% {
    top: 0;
    opacity: 1;
  }
}