body {
  margin: 0;
  padding: 20px;
  display: flex;
  flex-direction: column;
  align-items: center;
  background: #aecfe5;
}

h1 {
  margin-top: 10px;
  margin-bottom: 10px;
  font-size: 55px;
}

p {
  margin-top: 0;
  margin-bottom: 20px;
  color: #555;
  font-size: 20px;
  font-weight: 500;
}

.all_cards {
  display: flex;
  flex-wrap: wrap;
  justify-content: center;
  gap: 20px;
  max-width: 800px;
}

/* CARD */

.card {
  width: 170px;
  height: 150px;
  border-radius: 16px;
  box-shadow: 0 8px 20px rgba(0, 0, 0, 0.1);
  cursor: pointer;
  transition: 0.3s;
  overflow: hidden;
  background-color: white;
}

.card:hover {
  transform: translateY(-5px) scale(1.03);
}

.card:active {
  transform: scale(0.97);
}

/* INNER */

.card_inner {
  width: 100%;
  height: 100%;
  position: relative;
}

/* FRONT */

.card_front {
  position: absolute;
  width: 100%;
  height: 100%;
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
}

.emoji {
  font-size: 40px;
}

.label {
  margin-top: 10px;
  font-size: 20px;
  color: #333;
}

/* BACK */

.card_back {
  position: absolute;
  width: 100%;
  height: 100%;
  padding: 15px;
  box-sizing: border-box;
  border-radius: 16px;
  background-color: #f4f8ff;
  display: none;
}

.card_back h3 {
  margin: 0 0 12px 0;
  font-size: 20px;
  font-weight: 600;
  text-align: center;
  color: #333;
}

.card_back ul {
  margin: 0;
  padding-left: 18px;
}

.card_back li {
  font-size: 15px;
  margin-bottom: 6px;
  font-weight: 500;
  line-height: 1.5;
  color: #333;
}

/* FLIP LOGIC */

.card.flipped .card_front {
  display: none;
}

.card.flipped .card_back {
  display: block;
}

/* SUPRISE BUTTON */

.surprise {
  margin-top: 30px;
  display: flex;
  flex-direction: column;
  align-items: center;
}

#btn {
  background-color: white;
  color: #333;
  border: none;
  border-radius: 12px;
  padding: 10px 24px;
  font-size: 20px;
  font-weight: 600;
  box-shadow: 0 8px 20px rgba(0, 0, 0, 0.1);
  cursor: pointer;
  transition: 0.3s;
}

#btn:hover {
  transform: translateY(-4px) scale(1.03);
}

#btn:active {
  transform: scale(0.97);
}

#res {
  margin-top: 10px;
  font-size: 20px;
  font-weight: 500;
  color: #555;
  text-align: center;
}

/* MOBILE */

@media (max-width: 600px) {
  .card {
    width: 140px;
    height: 150px;
  }
}