.flex-box {
  display: flex;
  flex-wrap: wrap;
}

.flex-box img {
  vertical-align: top;
}

.thumnail-left-box {
  width: 70%;
  margin: 0;
  padding: 0 0 2.5%;
}

.thumnail-left-box img {
  width: 100%;
}

.thumnail-right-box {
  width: 30%;
  margin: 0;
  padding: 0;
  list-style: none;
}

.thumnail-right-box li {
  display: flex;
  flex-wrap: wrap;
  width: 40%;
  margin: 0 0 0 auto;
}

.thumnail-right-box li img {
  width: 100%;
  margin: 0 0 auto;
}