.big-feature {
  opacity: .8;
  border-radius: 10px;
  background-color: #202020;
  width: 31.333%;
  text-align: center;
  float: left;
  color: #fff;
  opacity: 1;
  padding: 4em;
  margin: 0 3% 6em 0;
  box-sizing: border-box; 
  -moz-box-sizing: border-box; 
  -webkit-box-sizing: border-box; 
}

.big-feature.last {
  margin-right: 0;
}

.big-feature h5 {
  font-size: 1em;
  margin-bottom: .5em;
  font-size: 2.4em;
  margin: 0;
  padding: 0;
}

.big-feature p {
  font-size: 1.6em;
  madrgin: 0;
}

.big-feature img {
  margin: 1em 0;
}
.seller-box p {
  text-align: justify; 
}

@media screen and (max-width: 640px) {
    .big-feature {
        width: 100%;
    }
}