body {
  background-color: #fff;
  display: flex;
  justify-content: center;
  padding: 40px;
  font-family: sans-serif;
}

#form-container {
  position: relative;
  display: grid;
  justify-items: center;
  width: 500px;
  height: 320px;
}

/* FRONT CARD */
.card-front {
  background-color: #e4e4e4;
  border-radius: 8px;
  padding: 20px 30px;
  width: 390px;
  height: 250px;
  box-sizing: border-box;
  color: black;
  display: grid;
  grid-template-columns: 1fr 1fr;
  grid-template-rows: auto auto auto;
  gap: 1rem;
  z-index: 2;
  position: absolute;
  top: 0;
  left: 0;
  box-shadow: 0 4px 10px rgba(0,0,0,0.15);
}

.total-container {
  grid-column: 1 / -1;
  display: flex;
  justify-content: space-between;
  align-items: center;
}

.cardnumber-container {
  grid-column: 1 / -1;
}

.cardholder-container {
  grid-column: 1;
}

.expiration-container {
    grid-column: 2;
    display: grid;
    grid-template-columns: repeat(2, 1fr);
    column-gap: 0.5rem;
}

.expiration-container label {
  grid-column: 1 / -1;
  font-weight: normal; 
  margin-bottom: 0.25rem;
}

.expiration-container input {
  width: 60px;                 
  height: 32px;                
  padding: 6px 8px;            
  font-size: 14px;             
  text-align: center;
  border: 1px solid #ccc;
  border-radius: 4px;
  box-sizing: border-box;
}


/* BACK CARD */
.card-back {
  background-color: #ccc;
  border-radius: 8px;
  width: 430px;
  height: 250px;
  position: absolute;
  top: 60px; 
  left: 80px; 
  z-index: 1;
  display: grid;
  grid-template-rows: 50px 1fr;
  box-sizing: border-box;
  box-shadow: 0 4px 10px rgba(0,0,0,0.1);
}

#card-stripe {
  background-color: #3d5266;
  width: 100%;
  height: 50px;
  margin-top: 20px;
}

.cvv-container {
  align-self: end;
  justify-self: end;
  padding: 0 25px 20px 0; 
}

.cvv-container label {
  display: block;
  font-size: 14px;
  margin-bottom: 0.25rem;
}

.cvv-container input {
  width: 60px;
  padding: 0.4rem;
  text-align: center;
  font-size: 14px;
  border: 1px solid #aaa;
  border-radius: 4px;
}

#card-btn {
  position: absolute;
  bottom: -55px;
  right: 0;
  background-color: #f0f0f0;
  border: 1px solid #000;
  border-radius: 5px;
  padding: 8px 16px;
  cursor: pointer;
}