* {
  box-sizing: border-box;
  margin: 0;
  padding: 0;
}

body {
  background-color: aliceblue;
}

body,
html {
  color: #1a1a1a;
  font-family: PingFangSC, Microsoft YaHei, Roboto, Helvetica Neue, Helvetica,
    Tahoma, Arial;
  width: 100%;
  height: 100%;
  overflow: hidden;
}

.logo {
  height: 48px;
  margin-right: 24px;
}

.logo > img {
  width: 42px;
}

.top {
  height: 48px;
  width: 100%;
  display: flex;
  align-items: center;
  justify-content: flex-start;
  background-color: #1890ff;
  color: white;
  padding: 0 24px;
}

.top > .tab {
  margin-right: 24px;
  font-size: 14px;
  cursor: pointer;
}

.top > .tab:hover {
  color: #e2e5e8;
}

.middle {
  height: calc(100% - 48px - 24px);
  width: 100%;
  overflow-x: hidden;
  overflow-y: scroll;
  display: flex;
  justify-content: center;
  align-items: flex-start;
}

.bottom {
  font-size: 12px;
  color: gray;
  display: flex;
  align-items: center;
  justify-content: center;
  padding: 4px;
  height: 24px;
}

.middle > .box {
  width: 1200px;
  padding: 8px;
}

.hidden {
  display: none;
}

.middle > .box > div {
  padding: 4px;
  display: flex;
  align-items: center;
  justify-content: center;
  flex-wrap: wrap;
}

.img-50 > img {
  width: 50%;
}