.banner {
  background: url('../img/about.jpeg');
  background-size: 100% 100%;
  height: 376px;
  margin-top: 79px;
}

.banner h2 {
  width: 15%;
  float: left;
  color: #fff;
  font-size: 40px;
  font-family: PingFangSC-Regular;
  font-weight: 400;
  color: rgba(255, 255, 255, 1);
  line-height: 70px;
  margin-top: 5%;
  margin-left: 10%;
  padding-bottom: 33px;
  border-bottom: 1px solid #979797;
  text-align: left;
}

.problem {
  width: 60%;
  margin: 0 auto;
  margin-top: 30px;
  line-height: 30px;
  border-bottom: 1px solid #ccc;
  padding-bottom: 30px;
}

.problem p {
  margin-top: 15px;
  display: -webkit-box;
  -webkit-box-orient: vertical;
  -webkit-line-clamp: 3;
  overflow: hidden;
  cursor: pointer;
}