body {
  margin: 0;
  font-family: Arial, Helvetica, sans-serif;
  background: #ffffff;
  color: #111;
}

.page {
  padding: 24px;
}

.errors {
  color: #b00020;
  white-space: pre-line;
  min-height: 1.2em;
  margin-bottom: 10px;
}

.form-grid {
  position: relative;
  width: 520px;
  height: 270px;
}

.card-front {
  position: absolute;
  left: 0;
  top: 0;
  width: 330px;
  height: 170px;
  padding: 16px 16px 12px;
  background: #d4d4d4;
  border-radius: 8px;
  box-shadow: 0 10px 14px rgba(0,0,0,.25);
  display: grid;
  grid-template-columns: 1fr 1fr;
  grid-template-areas:
    "total icon"
    "number number"
    "name exp";
  gap: 10px;
  z-index: 3;
}

.total {
  grid-area: total;
  margin: 0;
  font-weight: 700;
  font-size: 13px;
}

.icon {
  grid-area: icon;
  justify-self: end;
  font-size: 18px;
}

.field.number { grid-area: number; }
.field.name { grid-area: name; }
.field.expiration { grid-area: exp; }

label {
  display: block;
  font-size: 11px;
  margin-bottom: 4px;
}

input {
  width: 70%;
  padding: 6px 7px;
  border: 1px solid #9a9a9a;
  border-radius: 3px;
  background: #f7f7f7;
  font-size: 11px;
}

.exp-row {
  display: grid;
  grid-template-columns: 42px 42px;
  gap: 10px;
}

.card-back {
  position: absolute;
  left: 90px;
  top: 70px;
  width: 330px;
  height: 170px;
  background: #cfcfcf;
  border-radius: 8px;
  box-shadow: 0 10px 14px rgba(0,0,0,.25);
  padding: 14px;
  z-index: 1;
}

.mag-strip {
  height: 40px;
  background: #111;
  border-radius: 3px;

  width: calc(100% + 28px);
  margin-left: -14px;
}

.field.cvc {
  position: absolute;
  right: 14px;
  top: 80px;
  width: 50px;
}

.submit-btn {
  position: absolute;
  right: 80px;
  bottom: -50px;
  padding: 8px 18px;
  border: 1px solid #222;
  border-radius: 7px;
  background: #efefef;
  cursor: pointer;
  box-shadow: 0 6px 10px rgba(0,0,0,.25);
  font-size: 12px;
  z-index: 10;
}

@media (max-width: 560px) {
  .form-grid {
    width: 100%;
    height: auto;
    display: grid;
    gap: 12px;
  }

  .card-front,
  .card-back,
  .submit-btn {
    position: static;
    width: 100%;
  }

  .card-back {
    height: auto;
  }

  .field.cvc {
    position: static;
    width: 120px;
    margin-top: 12px;
  }

  .submit-btn {
    justify-self: end;
  }
}