/* .List
---------------------------------------------------------- */
.introduction {
  list-style: none;
  padding: 0;
}

.introduction_item {
  position: relative;
  float: left;
  width: 200px;
}

.introduction_item:not(:first-child) {
  margin-left: 40px;
}

.introduction_img {
  display: block;
  position: relative;
  background-size: contain;
  background-repeat: no-repeat;
  width: 200px;
  height: 173px;
}

.introduction_item:nth-child(1) .introduction_img { background-image: url(../img/pic_tracking01.jpg);}
.introduction_item:nth-child(2) .introduction_img { background-image: url(../img/pic_variable01.jpg);}
.introduction_item:nth-child(3) .introduction_img { background-image: url(../img/pic_fixed01.jpg);}

.introduction_img > img {
  display: block;
  position: absolute;
  top: 0;
  opacity: 0;
  z-index: 99;
  cursor: pointer;
  -webkit-transition: all .25s linear;
  -o-transition: all .25s linear;
  transition: all .25s linear;
}

.introduction_img:hover > img {
  opacity: 1;
  -webkit-transform: scale(2.59);
  -ms-transform: scale(2.59);
  -o-transform: scale(2.59);
  transform: scale(2.59);
  height: auto;
}

.introduction_item:nth-child(1) .introduction_img > img {
  -webkit-transform-origin: top left;
  -moz-transform-origin: top left;
  -ms-transform-origin: top left;
  -o-transform-origin: top left;
  transform-origin: top left;
}

.introduction_item:nth-child(2) .introduction_img > img {
  -webkit-transform-origin: top center;
  -moz-transform-origin: top center;
  -ms-transform-origin: top center;
  -o-transform-origin: top center;
  transform-origin: top center;
}

.introduction_item:nth-child(3) .introduction_img > img {
  -webkit-transform-origin: top right;
  -moz-transform-origin: top right;
  -ms-transform-origin: top right;
  -o-transform-origin: top right;
  transform-origin: top right;
}

.introduction_dl {
  margin-top: 12px;
}

.introduction_dt {
  display: block;
  font-size: 1.8rem;
}

.introduction_dt::before {
  display: inline;
  content: "●";
  margin-right: .45rem;
}

.introduction_item:nth-child(1) .introduction_dt::before { color: #00a0e9;}
.introduction_item:nth-child(2) .introduction_dt::before { color: #64b72f;}
.introduction_item:nth-child(3) .introduction_dt::before { color: #e60012;}

.introduction_dd {
  font-size: 1.3rem;
  margin: 4px 0 0 2.4rem;
}