* {
  border: 1px solid;
}

/* 头部标题 */
.header {
  display: flex;
  padding: 10px;
  background-color: #eee;
  font-size: 1.6em;
  line-height: 1.5;
  letter-spacing: 0.034em;
  font-family: "思源黑体";
  justify-content: center;
}
.headertext {
  display: flex;
  max-width: 460px;
  align-items: center;
  flex-direction: row;
  text-align: center;
}
.header h1 {
  font-size: 50px;
}
/* 响应式布局 -屏幕尺寸小于400px时，标题图片与文字上下分布 */
@media screen and (max-width: 400px) {
  .header {
    display: flex;
    padding: 10px;
    background-color: #eee;
    font-size: 1.6em;
    line-height: 1.5;
    letter-spacing: 0.034em;
    font-family: "思源黑体";
    justify-content: center;
    flex-direction: column;
  }
}

/* 导航条 */
.topnav {
  overflow: hidden;
  background-color: #000000;
}

/* 导航条链接 */
.topnav a {
  float: left;
  display: block;
  color: #ffffff;
  text-align: center;
  padding: 14px 16px;
  text-decoration: none;
  align-items: center;
}

/* 响应式布局 -屏幕尺寸小于 400px 时，导航等布局改为上下布局 */
@media screen and (max-width: 400px) {
  .topnav a {
    float: none;
    width: 100%;
  }
}

/* 链接颜色修改 */
.topnav a:hover {
  background-color: rgb(255, 255, 255);
  color: rgb(0, 0, 0);
}

/* 底部栏目样式 */
.dibulan {
  width: 100%;
  height: 160px;
  background-color: #eee;
  display: flex;
  align-items: center;
  flex-direction: column;
}
.dibulan-text {
  display: flex;
  flex-direction: row;
  align-items: center;
  padding: 10px;
}

/* 部分链接样式 */
.abq:link,
.abq:visited {
  text-decoration: none;
  color: black;
}
.abq:hover {
  text-decoration: underline;
  color: orange;
}

.card {
  background-color: rgb(255, 255, 255);
  padding: 20px;
  margin-top: 20px;
}
.zi {
  background-color: rgb(255, 255, 255);
  text-indent: 2em;
}