/* Reset and base styles */
* {
  margin: 0;
  padding: 0;
  box-sizing: border-box;
}

:root {
  /* Primary colors */
  --gradient-start: hsl(249, 99%, 64%);
  --gradient-end: hsl(278, 94%, 30%);
  --red: hsl(0, 100%, 66%);

  /* Neutral colors */
  --white: hsl(0, 100%, 100%);
  --gray-light: hsl(270, 3%, 87%);
  --gray-medium: hsl(212, 12%, 71%);
  --purple-dark: hsl(278, 68%, 11%);
}

body {
  font-family: 'Space Grotesk', sans-serif;
  font-weight: 500;
  font-size: 18px;
  min-height: 100vh;
  display: flex;
  flex-direction: column;
  background-color: var(--white);
}

main {
  flex: 1;
}

.container {
  display: flex;
  flex-direction: column;
  align-items: center;
  width: 100%;
}

/* Card styles */
.card-container {
  position: relative;
  width: 100%;
  height: 240px;
  background-image: url('./images/bg-main-mobile.png');
  background-repeat: no-repeat;
  background-size: cover;
  margin-bottom: 48px;
}

.card-front, .card-back {
  position: absolute;
  width: 285px;
  height: 157px;
  border-radius: 10px;
  box-shadow: 0 20px 60px rgba(0, 0, 0, 0.1);
  background-size: cover;
  background-repeat: no-repeat;
}

.card-front {
  background-image: url('./images/bg-card-front.png');
  padding: 20px;
  display: flex;
  flex-direction: column;
  justify-content: space-between;
  top: 126px;
  left: 50%;
  transform: translateX(-53%);
  z-index: 2;
}

.card-back {
  background-image: url('./images/bg-card-back.png');
  top: 32px;
  left: 50%;
  transform: translateX(-47%);
  display: flex;
  align-items: center;
  justify-content: flex-end;
}

.card-logo {
  width: 54px;
  height: auto;
}

.card-number-display {
  color: var(--white);
  font-size: 18px;
  letter-spacing: 2px;
  margin-top: auto;
}

.card-info {
  display: flex;
  justify-content: space-between;
  color: var(--white);
  font-size: 12px;
  text-transform: uppercase;
  letter-spacing: 1px;
}

.card-cvc-display {
  color: var(--white);
  font-size: 14px;
  margin-right: 38px;
}

/* Form styles */
.form-container {
  width: 100%;
  max-width: 380px;
  padding: 0 24px;
}

.form-group {
  margin-bottom: 20px;
}

label {
  display: block;
  color: var(--purple-dark);
  font-size: 12px;
  text-transform: uppercase;
  letter-spacing: 2px;
  margin-bottom: 8px;
}

input {
  width: 100%;
  padding: 12px;
  border: 1px solid var(--gray-light);
  border-radius: 8px;
  font-family: 'Space Grotesk', sans-serif;
  font-size: 18px;
  color: var(--purple-dark);
}

input::placeholder {
  color: var(--gray-medium);
}

input:focus {
  outline: none;
  border-image: linear-gradient(to right, var(--gradient-start), var(--gradient-end)) 1;
}

input.error {
  border-color: var(--red);
}

.error-message {
  color: var(--red);
  font-size: 12px;
  margin-top: 8px;
  min-height: 16px;
}

.form-row {
  display: flex;
  gap: 16px;
}

.expiry-date {
  flex: 1;
}

.expiry-inputs {
  display: flex;
  gap: 8px;
}

.expiry-inputs > div {
  flex: 1;
}

.cvc-group {
  flex: 1;
}

.submit-button {
  width: 100%;
  padding: 15px;
  background-color: var(--purple-dark);
  color: var(--white);
  border: none;
  border-radius: 8px;
  font-family: 'Space Grotesk', sans-serif;
  font-size: 18px;
  cursor: pointer;
  transition: background-color 0.3s;
}

.submit-button:hover {
  background-color: hsl(278, 68%, 15%);
}

/* Completed state styles */
.completed-state {
  width: 100%;
  max-width: 380px;
  padding: 0 24px;
  text-align: center;
}

.complete-icon {
  margin-bottom: 32px;
}

.completed-state h2 {
  color: var(--purple-dark);
  text-transform: uppercase;
  letter-spacing: 3px;
  margin-bottom: 16px;
}

.completed-state p {
  color: var(--gray-medium);
  margin-bottom: 48px;
}

.continue-button {
  width: 100%;
  padding: 15px;
  background-color: var(--purple-dark);
  color: var(--white);
  border: none;
  border-radius: 8px;
  font-family: 'Space Grotesk', sans-serif;
  font-size: 18px;
  cursor: pointer;
  transition: background-color 0.3s;
}

.continue-button:hover {
  background-color: hsl(278, 68%, 15%);
}

/* Desktop styles */
@media (min-width: 1024px) {
  body {
    overflow-x: hidden;
  }

  .container {
    flex-direction: row;
    justify-content: center;
    gap: 120px;
    min-height: 100vh;
  }

  .card-container {
    width: 483px;
    height: 100vh;
    background-image: url('./images/bg-main-desktop.png');
    margin-bottom: 0;
    display: flex;
    justify-content: center;
    align-items: center;
  }

  .card-front {
    width: 447px;
    height: 245px;
    top: calc(50% - 140px);
    left: 164px;
    padding: 28px;
  }

  .card-back {
    width: 447px;
    height: 245px;
    top: calc(50% + 40px);
    left: 230px;
  }

  .card-logo {
    width: 84px;
  }

  .card-number-display {
    font-size: 28px;
    letter-spacing: 3.5px;
  }

  .card-info {
    font-size: 14px;
  }

  .card-cvc-display {
    font-size: 14px;
    margin-right: 60px;
  }

  .form-container, .completed-state {
    margin-top: 0;
    padding: 0;
    display: flex;
    justify-content: center;
    align-items: center;
  }

  .form-container form {
    width: 380px;
  }
}

/* Tablet styles */
@media (min-width: 768px) and (max-width: 1023px) {
  .card-container {
    height: 300px;
  }

  .card-front {
    width: 340px;
    height: 186px;
    top: 140px;
    left: 50%;
    transform: translateX(-55%);
  }

  .card-back {
    width: 340px;
    height: 186px;
    top: 30px;
    left: 50%;
    transform: translateX(-45%);
  }

  .card-number-display {
    font-size: 22px;
  }

  .form-container, .completed-state {
    max-width: 450px;
    margin: 0 auto;
    padding-top: 30px;
  }
}