.letter_box .clearfix:after {
  content: ".";
  display: block;
  clear: both;
  visibility: hidden;
  line-height: 0;
  height: 0;
  font-size: 0;
}
.letter_box .margin_right0 {
  margin-right: 0 !important;
}
.letter_box .main {
  width: 1200px;
  height: auto;
  margin: auto;
  margin-top: 30px;
  margin-bottom: 30px;
}
.letter_box .main .left_box {
  float: left;
  width: 16.6%;
  height: 550px;
  border: 1px solid #2E89DA;
}
.letter_box .main .left_box .title_one {
  height: 45px;
  background-color: #2E89DA;
  color: #FFF;
  line-height: 45px;
  text-align: center;
  font-size: 15px;
  font-weight: 700;
}
.letter_box .main .left_box ul li {
  height: 40px;
  line-height: 40px;
  text-align: center;
  cursor: pointer;
}
.letter_box .main .left_box ul li.active {
  color: #000;
  background-color: #DAEEF9;
}
.letter_box .main .right_box {
  float: right;
  width: 100%;
  height: 642px;
  border: 1px solid #2E89DA;
}
.letter_box .main .right_box > div {
  height: 100%;
  display: none;
}
.letter_box .main .right_box > div.active {
  display: block;
}
@media (max-width: 750px) {
  .letter_box {
    width: 100%;
  }
  .letter_box .main {
    width: 100%;
    border: none;
    margin: 0.3rem 0;
    height: auto;
  }
  .letter_box .main .right_box {
    border: none;
    min-height: 6.6rem;
    max-height: 8rem;
  }
}