body {
  font-size: 14px;
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", "PingFang SC",
    "Hiragino Sans GB", "Microsoft YaHei", "Helvetica Neue", Helvetica, Arial,
    sans-serif, "Apple Color Emoji", "Segoe UI Emoji", "Segoe UI Symbol";
}
p{
  color: #999;
}
img {
  width: auto;
  height: auto;
  max-width: 100%;
}

img.header-logo {
  max-height: 60px;
}

img.footer-logo {
  max-height: 45px;
}
.zoom-out,
.zoom-in {
  position: relative;
  overflow: hidden;
  -webkit-backface-visibility: hidden;
  backface-visibility: hidden;
}

.zoom-out img,
.zoom-in img {
  transition: all 0.3s ease-in-out;
  -webkit-backface-visibility: hidden;
  backface-visibility: hidden;
}

.zoom-in:hover img {
  -webkit-transform: scale(1.15);
  transform: scale(1.15);
}

.zoom-out:hover img {
  -webkit-transform: scale(0.85);
  transform: scale(0.85);
}
@media (min-width: 1680px) {
  .container,
  .container-sm,
  .container-md,
  .container-lg,
  .container-xl {
    max-width: 1360px;
  }
}
/* 首页 */
.section02{
  background: url("../images/teachingBackGround.png") repeat center top / cover;
}
.bg-dark a{
  color: #999;
}

.btn-primary {
  background-color: #20ad96;
  border-color: #20ad96;
}

.btn-primary:hover {
  background-color: #222;
  border-color: #222;
}

.btn-lg, .btn-group-lg > .btn {
  padding: 1rem 2rem;
  border-radius: 3rem;
}