online/src/index.css

body {
  margin: 0;
  padding: 0;
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", "Roboto", "Oxygen",
    "Ubuntu", "Cantarell", "Fira Sans", "Droid Sans", "Helvetica Neue",
    sans-serif;
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
}

code {
  font-family: source-code-pro, Menlo, Monaco, Consolas, "Courier New",
    monospace;
}

.logo {
  width: 25%;
  height: 31px;
  padding: 16px 24px 16px 70px;
  float: left;
}
.logo img {
  width: 25%;
  padding: 0 0 40px 20px
}

.login {
  width: 25%;
  /*color: #ffffff;*/
  line-height: 31px;
}

.home-btn {
    background: #fff;
    padding: 24px;
    min-height: 280px;
    display: flex;
    justify-content: center;
    /*align-items: center;*/
    margin-top: 20px;
}

.ant-card-head-title {
    padding: 16px 0;
    text-overflow: ellipsis;
    overflow: hidden;
    white-space: nowrap;
    flex: 1 1;
    display: inline-block;
    font-weight: 600;
    color: #1890ff;
    font-size: 20px;
}

.brief{
    text-align: center;
    font-size: 25px;
    color: #3b3b3c;
    margin-top: 30px;
}

.intro-card p{
    padding-bottom: 10px;
    color: black;
}

.intro-card .ant-card {
    background-color: #f4f5f7;
    min-height: 214px;
}