body {
  margin: 0;
  padding: 0;
  font-family: arial;
  font-size: 14px;
}

* {
  outline: none;
}


h2 {
  font-size: 22px;
  margin: 15px 0;
}

a {
  color: black;
}

.cards {
  font-size: 0;
}

.card {
  width: 187px;
  display: inline-block;
  font-size: 14px;
  height: 260px;
  overflow: hidden;

}

.card img {
  display: block;
}

.front, .back {
  background: white;
}

.buttons {
  margin-top: 15px;
  text-align: center;
}

.buttons input {
  color: green;
  background: white;
  border: 1px solid green;
  cursor: pointer;
  padding: 3px 4px;
  border-radius: 3px;
}

.buttons input:hover {
  background: #def0cc
}

.buttons input.no {
  color: red;
  border-color: red;
  margin-left: 4px;
}


.buttons input.no:hover {
  background: #f9d5d8;
}

.row {
  height: 270px;

}

.card .back .text {
  display: none;
}

.card .back .text img {
  display: block;
}

.card .back .text.incorrect {
}

.again {
  font-size: 18px;
  font-weight: bold;
  text-align: center;
  margin: 20px 0;
  visibility: hidden;
}