body {
  width: 100%;
  height: 600vh;
  margin: 0;
  background-color: #000;
}

.container {
  width: 1000px;
  height: 100vh;
  margin: 0 auto;
  position: sticky;
  top: 0;
  color: #fff;
  display: flex;
  flex-direction: column;
}

video {
  width: 400px;
  display: block;
  margin: auto;
}

.txt-item {
  position: absolute;
  width: 280px;
  font-weight: bold;
  color: gray;
  transition: all .8s linear;
  letter-spacing: 1px;
  text-align: center;
  font-size: 13px;
  opacity: 0;
}

.txt-item span {
  color: yellowgreen;
}

.txt-item.active {
  opacity: 1;
}

.txt-item:nth-child(2) {
  top: 80%;
  left: 50%;
  transform: translateX(-50%);
}

.txt-item:nth-child(3) {
  width: 230px;
  padding-top: 15px;
  top: 60%;
  left: 60%;
}

.txt-item:nth-child(3) .txt {
  transition: all .3s linear;
  transform: translateY(50px);
}

.txt-item:nth-child(3) .line {
  border-top: 1px solid gray;
  position: absolute;
  top: 0;
  right: 0;
  width: 0;
  transition: all .5s linear;
}

.txt-item:nth-child(3).active .txt {
  transform: translateY(0);
}

.txt-item:nth-child(3).active .line {
  width: 300px;
}

.txt-item:nth-child(4) {
  top: 75%;
  left: 58%;
}

.txt-item:nth-child(4) .line {
  position: absolute;
  left: -20px;
  border-left: 1px solid gray;
  height: 0;
  bottom: 0;
  transition: all .5s;
}

.txt-item:nth-child(4).active .line {
  height: 130px;
}

.txt-item:nth-child(5) {
  top: 80%;
  left: 50%;
  transform: translateX(-50%);
}