body {
  background-image: url(media/aboutbg.jpeg);
  animation: diagonalMove 10s linear infinite;
  background-color: black;
  color: white;
  font-size: 24px;
  font-family: "ＭＳ Ｐゴシック", serif;
}
.banner {
  display: flex;
  flex-direction: row;
  justify-content: start;
  align-items: center;
  width: 100%;
  overflow: hidden;
}

.tf-box {
  display: flex;
  flex-direction: column;
  align-items: start;
  width: 100%;
}

.tf-box video {
  display: block;
  margin: 0;
  padding: 0;
  flex: 1 1 auto;
  width: 100%;
}

.tf-box p {
  display: block;
  margin: 0;
  padding: 0;flex: 1 1 auto;
  font-size: 50%;
  word-wrap: break-word;
  text-align: center;
  color: lightgray;
}

.banner-txt {
  display: flex;
  flex-direction: row;
  justify-content: start;
  align-items: center;
  width: 100%;
  overflow: hidden;
}

.banner-txt p {
  display: block;
  margin: 0;
  padding: 0;flex: 1 1 auto;
  width: 20rem;
}

.about {
  padding: 10rem;
  padding-top: 1%;
  padding-bottom: 1%;
}

@keyframes diagonalMove {
  0% {
    background-position: 0 0;
  }
  100% {
    background-position: 100px 100px;
  }
}