body {
  font-family: "Microsoft YaHei", Arial;
  overflow-x: hidden;
  overflow-y: auto;
}
.main {
  max-width: 640px;
  min-width: 150px;
  margin: 0 auto;
  text-align: justify;
  line-height: 1.6;
  padding-bottom: 20px;
}

@media screen and (max-width: 321px) {
  body {
    font-size: 12px;
  }
  .headtxt {
    font-size: 16px;
  }
}

@media screen and (min-width: 321px) and (max-width: 400px) {
  body {
    font-size: 14px;
  }
  .headtxt {
    font-size: 18px;
  }
}

@media screen and (min-width: 400px) {
  body {
    font-size: 16px;
  }
  .headtxt {
    font-size: 20px;
  }
}

.content {
  padding: 20px;
}
.content1 {
  padding: 16px 22px;
}
.content2 {
  padding: 10px 22px 16px 16px;
}
.headtxt {
  text-align: center;
}
.bold {
  font-weight: bold;
}
.right {
  text-align: right;
}

.top12 {
  padding-top: 12px;
}
.top20 {
  padding-top: 20px;
}
.logo {
  display: block;
  margin: 36px auto 0 auto;
  width: 20%;
}
.f12 {
  font-size: 12px;
}
.c999 {
  color: #999;
}
.about_bottom {
  text-align: center;
  font-size: 12px;
  color: rgba(153,153,153,1);
  margin: 0 auto;
  width: 100%;
  line-height: 20px;
}
.beian {
  margin-top: 12px;
}
.beian_link {
  color: #37a9f8;
}
.about_bg {
  background: url(../images/about_btm.png) fixed right bottom no-repeat;
  background-size: 265px 255px;
}