.kb_dashboard {
  width: 1920px;
  height: 1080px;
  position: relative;
  background-color: lightblue;
  font-size: 20px;
  font-family: Microsoft YaHei;
}

.kb_header {
  background-color: #00a79d;
  height: 90px;
  line-height: 90px;
  font-size: 40px;

}

.kb_content {
  display: flex;
  position: relative;
  height: 990px;
}

.kb_left {
  width: 30%;
  height: 100%;
}

.kb_center {
  width: 40%;
  background-color: #00a79d;
  height: 100%;
}

.kb_right {
  width: 30%;
  height: 100%;
}

.flex_c_c {
  display: flex;
  justify-content: center;
  align-content: center;
}

.flex_c_s {
  display: flex;
  flex-direction: column;
  justify-content: space-evenly;
  /*align-content: center;*/
}

.kb_block{
  display: flex;
  align-content: center;
  justify-content: center;
  width: 556px;
  height: 400px;
  line-height: 400px;
  background-image: linear-gradient(to bottom right, red , yellow);
  /*background-image: repeating-radial-gradient(red, yellow 10%, green 15%);*/

  /*background-color: #5a5e66;*/
  margin: 10px;
}