* {
  box-sizing: border-box
}

body {
  margin: 0;
  background: #f8fafc;
  font-family: "Microsoft YaHei", Arial, sans-serif;
  color: #334155
}

.about-page {
  display: flex;
  width: min(calc(100% - 48px), 1400px);
  gap: 40px;
  margin: 0 auto;
  padding: 48px 0 64px
}

.about-page aside {
  flex: 0 0 260px
}

.about-page aside h2 {
  margin: 0;
  border-radius: 8px 8px 0 0;
  padding: 14px;
  background: #0756ad;
  color: #fff;
  font-size: 16px;
  text-align: center
}

.about-page nav {
  overflow: hidden;
  border: 1px solid #e2e8f0;
  border-top: 0;
  border-radius: 0 0 8px 8px;
  background: #fff
}

.about-page nav a {
  display: block;
  border-bottom: 1px solid #f1f5f9;
  padding: 14px 16px;
  color: #475569;
  text-decoration: none
}

.about-page nav a.active,
.about-page nav a:hover {
  box-shadow: inset 3px 0 #f2b900;
  background: #f0f7ff;
  color: #0756ad;
  font-weight: 700
}

.about-page article {
  flex: 1;
  border: 1px solid #e2e8f0;
  border-radius: 12px;
  padding: 40px;
  background: #fff;
  line-height: 1.9
}

.about-page article h1 {
  margin: 0 0 30px;
  color: #0756ad;
  font-size: 26px;
  text-align: center
}

.about-page article h2 {
  margin-top: 30px;
  color: #1e3a5f;
  font-size: 18px
}

.about-page__content img {
  display: inline-block;
}

@media(max-width:900px) {
  .about-page {
    display: block;
    width: calc(100% - 24px);
    padding: 28px 0
  }

  .about-page aside {
    margin-bottom: 18px
  }

  .about-page aside h2 {
    display: none
  }

  .about-page nav {
    display: flex;
    overflow: auto;
    gap: 8px;
    border-top: 1px solid #e2e8f0;
    padding: 8px
  }

  .about-page nav a {
    flex: 0 0 auto;
    border: 0;
    border-radius: 6px;
    padding: 9px 13px;
    white-space: nowrap
  }

  .about-page article {
    padding: 24px 20px
  }
}