body {
  background: url('http://webfron.czczh.net/car/sites/nav/images/bg.png') no-repeat;
  background-size: 100% 100%;
}
.big-title {
  font-size: 20px;
  color:rgba(32,147,254,1);
  margin-bottom: 15px;
}
.title {
  margin: 15px 0;
  font-size: 14px;
  font-family:Microsoft YaHei;
  font-weight:400;
  color:rgba(0,0,0,1);
  text-align: center;
}
.title span:nth-child(2) {
  color:rgba(32,147,254,1);
}
.description {
  color: #333;
  font-size: 12px;
  text-align: center;
}
.icon {
  width: 60px;
  height: 60px;
  margin: 0 auto;
  background-position: center center;
}
.container-margin-top {
  margin-top: 30px;
}
.row-margin-top {
  margin-top: 15px;
}
.a-color {
  text-decoration: none;
}
.a-color:hover {
  text-decoration: none;
}
.contain-box {
display: flex;
flex-direction: column;
align-items: center;
text-align: center;
}
.box {
display: inline-block;
width: auto;
background:rgba(255,255,255,1);
box-shadow:0px 4px 44px 15px rgba(246,246,246,1);
border-radius:19px;
padding: 10px;
}
.item {
display: flex;
flex-direction: column;
align-items: center;
width: 176px;
height: auto;
float: left;
}
.erweima {
width: 100%;
margin-top: 15px;
text-align: center;
}
.erweima img {
width: 100px;
height: 100px;
}

@media (min-width: 768px) {
  .big-title {
      font-size: 36px;
  }
  .container-margin-top {
      margin-top: 50px;
  }
  .title {
      font-size: 22px;
      margin: 30px 0 15px;
  }
  .description {
      font-size: 16px;
  }
  .box {
    display: inline-block;
    width: auto;
    background:rgba(255,255,255,1);
    box-shadow:0px 4px 44px 15px rgba(246,246,246,1);
    border-radius:19px;
    padding: 30px;
  }
  .item {
    display: flex;
    flex-direction: column;
    align-items: center;
    width: 236px;
    height: auto;
    float: left;
    margin-top: 15px;
  }
  .erweima img {
    width: 160px;
    height: 160px;
  }

}
/* 中等屏幕（桌面显示器，大于等于 992px） */
@media (min-width: 992px) {
  .big-title {
      font-size: 50px;
  }
  .title {
      font-size: 24px;
      margin: 30px 0 15px;
  }
  .description {
      font-size: 18px;
  }
  .icon {
      width: 80px;
      height: 80px;
  }
  .container-padding {
      padding: 50px;
  }
  .container-margin-top {
      margin-top: 80px;
  }
  .row-margin-top {
      margin-top: 15px;
  }
  .box {
    display: inline-block;
    width: auto;
    background:rgba(255,255,255,1);
    box-shadow:0px 4px 44px 15px rgba(246,246,246,1);
    border-radius:19px;
  }
  .item {
    display: flex;
    flex-direction: column;
    align-items: center;
    width: 286px;
    height: auto;
    float: left;
  }
}