.event__list {
  display: -webkit-box;
  display: -ms-flexbox;
  display: flex;
  -ms-flex-wrap: wrap;
      flex-wrap: wrap;
  margin: 0 -10px;
}

.event__list__item {
  position: relative;
  width: calc(50% - 16px);
  margin: 16px 8px;
}

@media (min-width: 768px) {
  .event__list__item {
    width: calc(33.333% - 20px);
  }
}

.event__list__item .thumb {
  position: relative;
  background: #eee;
  margin-bottom: 12px;
}

.event__list__item .thumb:before {
  content: '';
  display: block;
  padding-top: 100%;
}