* {
    box-sizing: border-box;
}

body {
  margin: 0;
  font-family: "Helvetica";
}

#header {
  background-color: #f3f3f3;
  height: 40px;
  display: flex;
  align-items: center;
}

#header-image{
  height: 14px;
  width: 118px;
  margin-left: 14px;
}

.nav {
  display: inline-flex;
  list-style: none;
  font-size: 13px;
  font-weight: bold;
  align-items: flex-end;
}

.nav li {
  padding: 5px;
}

#wrapper {
  position: relative;
  padding-bottom: 150px;
  margin: 20px auto;
  display: block;
}

.content {
  -webkit-column-count: 1;
    -moz-column-count: 1;
    column-count: 1;
  color: #333;
  z-index: 2;
  text-align: center;
  position: relative;
  display: block;
  margin: 20px 20px 0 30px;
  clear: both;
}

.item-list {
  overflow: hidden;
  margin: 0 9px 0px;
  font-size: 12px;
}

.item-list img {
  width: 290px;
  height: 290px;
  border: 1px solid #cacaca;
  border-radius: 3px;
  opacity: 1;
  outline: 0;
  overflow: hidden;
  padding: 2px;
}

.shell {
  width: 320px;
}

.footer {
  font-size: 16px;
  color: #666;
  font-weight: bold;
  text-align: right;
  padding: 5px 5px 5px 5px;
  margin: 0 10px 22px;
  border-bottom: 1px solid #cacaca;
  position: relative;
}

.footer ::before {
  content: "";
  height: 0;
  width: 0;
  border: 8px solid transparent;
  border-top-color: #cacaca;
  margin-top: -3px;
  position: absolute;
  right: 7px;
  top: 0;
}

.number {
  float: left;
  margin: 10px 0 0 10px;
  color: #cacaca;
}

p {
  display: inline-block;
  padding: 0;
  -webkit-margin-before: .5em;
    -webkit-margin-after: .5em;
    -webkit-margin-start: 0px;
    -webkit-margin-end: 10px;
}


@media screen and (max-width: 320px) {
  .nav {
    margin-left: -25px;
    font-size: 12px;
  }
  .content {
    margin-left: 0;
  }
}

@media screen and (min-width: 768px) {
  #header {
    height: 52px;
  }
  #header-image {
    height: 22px;
    width: 175px;
    margin-left: 25px;
  }
  .nav {
    margin-left: 250px;
    font-size: 15px;
  }
  .nav li {
    padding: 10px;
  }
  .content {
    text-align: center;
  }
  .item-list img {
    width: 424px;
    height: 424px;
  }
  .shell {
    width: 450px;
    margin-left: 150px;
    margin-bottom: 30px;
  }
  .footer {
    margin: 0 10px 5px 10px;
  }
}

@media screen and (min-width: 1024px) {
  .nav {
    margin-left: 500px;
  }
  .content {
    -webkit-column-count: 3;
      -moz-column-count: 3;
      column-count: 3;
  }
  .item-list img {
    width: 290px;
    height: 290px;
  }
  .shell {
    width: 310px;
    height: 350px;
    margin-left: 0;
    margin-right: 0;
  }
}

@media screen and (min-width: 1280px) {
  .nav {
    margin-left: 775px;
  }
  .content {
    margin-left: 75px;
    margin-right: 20px;
  }
}

@media screen and (min-width: 1440px) {
  .nav {
    margin-left: 900px;
  }
  .content {
    -webkit-column-count: 3;
      -moz-column-count: 3;
      column-count: 3;
    margin-left: 40px;
  }
  .item-list img {
    width: 400px;
    height: 400px;
  }
  .shell {
    width: 434px;
    height: 434px;
  }
}

@media screen and (min-width: 1500px) {
  .nav {
    margin-left: 1000px;
    }
}

@media screen and (min-width: 1650px) {
  .nav {
    margin-left: 1175px;
  }
  .content {
    margin-left: 125px;
    margin-right: 125px;
  }
  .item-list img {
    width: 424px;
    height: 424px;
  }
  .shell {
    width: 450px;
    height: 527px;
  }
}