@media screen and (max-width: 640px) {
  video {
    max-width: 100% !important;
    height: auto !important;
  }
}
html body div.text_item {
  width: calc(50% - 32px);
  box-sizing: border-box;
}
@media (max-width: 960px) {
  html body h2 {
    font-size: 24px;
  }
  html body div.text_under {
    font-size: 16px;
  }
}
@media (max-width: 960px) {
  html body div.text_under {
    font-size: 15px;
  }
  html body div.text_item {
    width: 100%;
    margin-left: 0;
    margin-right: 0;
  }
}