html, body {
    height: 100%;
    margin: 0;
}

.jiff1 {
  background: url("up1.gif") center;
  background-size: cover;
  height: 100%;
}

.jiff2 {
  background: url("up2.gif") center;
  background-size: cover;
  height: 100%;
}

.jiff3 {
  background: url("up3.gif") center;
  background-size: cover;
  height: 100%;
}

.jiff4 {
  background: url("up4.gif") center;
  background-size: cover;
  height: 100%;
}

.jiff5 {
  background: url("up5.gif") center;
  background-size: cover;
  height: 100%;
}

.jiff6 {
  background: url("up6.gif") center;
  background-size: cover;
  height: 100%;
}

.jiff7 {
  background: url("up7.gif") center;
  background-size: cover;
  height: 100%;
}

.jiff8 {
  background: url("up8.gif") center;
  background-size: cover;
  height: 100%;
}

.jiff9 {
  background: url("up9.gif") center;
  background-size: cover;
  height: 100%;
}