.container {
    margin-top: 20px;
}
.col-md-2 {
    padding: 5px;
  }
.col-md-2 img {
    width: 130px;
}
h1 {
    text-align: center;
}
.m-bottom {
    margin-top: 20px;
}
.about {
    line-height: 1.62;
    letter-spacing: 4px;
    text-transform: uppercase;
    color: #525252;
    margin:2em 0;
  }
  .about::after {
    content: '';
    display: block;
    border-top: 1px solid #ddd;
    width: 6em;
    margin: 1.5em 0;
    text-align: center;
    margin-left: auto;
    margin-right: auto;
  }
  .intro {
    padding: 50px 0 90px;
    color: #fff;
    background: #0b1e2d;
  }
  .inner {
    width: 100%;
    max-width: 1100px;
    margin: 0 auto;
  }
  .box-1 {
    display: flex;
    flex-flow: row nowrap;
    justify-content: space-between;
    width: 100%;
    margin:  0 0 60px;
    line-height: 1.8;
  }
  .box-item {
    text-align: left;
    padding: 20px 30px 10px;
    flex: calc(100 / 3);
  }
  .inner .box-1 .box-item:not(:last-child) {
    border-right: 1px solid #fff;
  }
  .box-2 {
    border-top: 1px solid #fff;
  }
  .first {
    line-height: 2.0;
    text-indent: 30px;
  }
  @media  screen and (max-width:768px) {
    .inner {
      width: 100%;
      margin: 0 auto;
    }
    .box-1 {
      display: flex;
      flex-direction: column;
      justify-content: space-between;
      align-items: center;
    }
    .inner .box-1 .box-item:not(:last-child) {
      border-bottom: 1px solid #fff;
      border-right: none;
    }
    .intro {
      padding:20px 2px 5px 2px;
    }
  }
  .cooperation {
      width: 1000px;
      margin: 0 auto;
      /* border: 1px solid black; */
  }
  /* .maintenance {
    color: #fff;
    background: #0b1e2d;
  } */
  .maintenance ul {
      margin: 0 auto;
      /* border: 1px solid red; */
      width: 400px;
  }
  .maintenance ul li {
    /* border: 1px solid red; */
    list-style-type: none;
    /* width: 800px; */
    padding: 5px;
      
  }
  .maintenance ul li::before {
    content: "● ";
    padding: 10px;
  }
    .maintenance h3 {
      text-align: center;
  }
  .maintenance h1 {
      margin-top: 50px;
  }
  .maintenance img {
      width: 100px;
      margin: 0 auto;
      text-align: center;
  }
  .welcome {
      font-size: 16px;
  }
  .content {
      float: right;
      font-size: 20px;
  }
  .cert_img{
      width: 1000px;
      height: 320px;
      text-align: center;
      margin: 0 auto;
  }
  .re img {
      width: 1000px;
  }