* {
  box-sizing: border-box;
}

.content_row {
  display: flex;
  flex-wrap: wrap;
  justify-content: center;
  margin: auto;
  background-color: #ffffff;
  width: 80%;
  padding: 20px 20px;
  text-align: center;
}

.content_col {
  flex: 0 0 30%;
  padding: 20px 20px;
  text-align: left;
  border:0;
  margin:10px;
  background-color: #ffffff;
}

.content_col_half {
  flex: 0 0 45%;
  padding: 20px 20px;
  text-align: left;
  border:0;
  margin:10px;
  background-color: #ffffff;
}

.banner-parent {
  display: flex;
  justify-content: center;
  margin: auto;
}

.banner-child {
  flex: 1;
  justify-content: center;
}

.menu_row {
  display: flex;
  justify-content: center;
  flex-wrap: wrap;
  margin: auto;
  width: 80%;
}

.menu_col {
  flex: 0 0 20%;
  justify-content: center;
  text-align: center;
}

.classmate_row {
  display: flex;
  justify-content: center;
  flex-wrap: wrap;
  margin: auto;
  width: 80%;
  background-color: #ffffff;
}

.classmate_col {
  flex: 0 0 40%;
  padding: 20px 20px;
  justify-content: center;
  text-align: left;
  background-color: #ffffff;
  margin-top: 8px;
  vertical-align: middle;
  margin:10px;
  border:1px solid black;
}

.project_row {
  display: flex;
  justify-content: center;
  flex-wrap: wrap;
  margin: auto;
  width: 80%;
  background-color: #ffffff;
}

.project_col {
  flex: 0 0 80%;
  padding: 0px;
  justify-content: center;
  text-align: left;
  background-color: #ffffff;
}

.project_col_img {
  flex: 0 0 20%;
  padding: 0px;
  justify-content: center;
  text-align: left;
  background-color: #ffffff;
}

@media only screen and (max-width: 620px) {

  /* For mobile phones: */
  .content_row {
    width: 100%;
    padding: 0px;
  }

  .content_col, .classmate_col, .menu_col {
    flex: 0 0 100%;
  }
}