:root {
  --white: #ffffff;
  --light-blue: #e3f2fd;
  --blue-100: #bbdefb;
  --blue-200: #90caf9;
  --blue-300: #64b5f6;
  --blue-400: #42a5f5;
  --blue-500: #2196f3;
  --black: #212121;
  --grey-100: #f5f5f5;
  --grey-200: #eeeeee;
  --grey-300: #e0e0e0;
  --grey-400: #bdbdbd;
  --grey-500: #9e9e9e;
  --error-red: #ff3333;
  --success-green: #4caf50;
  --warning-orange: #ff9800;
  --accent-teal: #009688;
}

* {
  margin: 0;
  padding: 0;
  box-sizing: border-box;
}

body {
  font-family: "Arial", sans-serif;
  background-color: var(--light-blue);
  color: var(--black);
  line-height: 1.6;
  min-height: 100vh;
  display: flex;
  flex-direction: column;
}

.header {
  background-color: var(--white);
  box-shadow: 0 2px 5px rgba(0, 0, 0, 0.1);
  padding: 1rem 0;
  position: fixed;
  width: 100%;
  top: 0;
  z-index: 1000;
}

.header-content {
  max-width: 1200px;
  margin: 0 auto;
  padding: 0 20px;
  display: flex;
  justify-content: space-between;
  align-items: center;
}

.logo {
  color: var(--black);
  font-size: 1.5rem;
  font-weight: bold;
}

.nav {
  display: flex;
  gap: 1.5rem;
}

.nav a {
  color: var(--black);
  text-decoration: none;
  padding: 0.5rem 1rem;
  border-radius: 4px;
  transition: background-color 0.3s, transform 0.2s;
}

.nav a:hover,
.nav a.active {
  background-color: var(--light-blue);
  transform: translateY(-2px);
}

.main-content {
  margin-top: 100px;
  padding: 2rem;
  max-width: 1200px;
  margin-left: auto;
  margin-right: auto;
}

.credit-balance {
  background-color: var(--white);
  padding: 2rem;
  border-radius: 12px;
  margin-bottom: 3rem;
  text-align: center;
  box-shadow: 0 8px 24px rgba(0, 0, 0, 0.08);
  transition: transform 0.3s ease;
}

.credit-balance:hover {
  transform: translateY(-4px);
}

.credit-packages {
  text-align: center;
}

.credit-packages h1 {
  margin-bottom: 2.5rem;
  color: var(--blue-500);
  position: relative;
  padding-bottom: 1rem;
}

.credit-packages h1::after {
  content: "";
  position: absolute;
  bottom: 0;
  left: 50%;
  transform: translateX(-50%);
  width: 60px;
  height: 3px;
  background-color: var(--blue-300);
  border-radius: 2px;
}

.packages-container {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 2.5rem;
  margin-top: 2.5rem;
}

.package-card {
  background: var(--white);
  border-radius: 12px;
  padding: 2.5rem;
  position: relative;
  transition: all 0.3s ease;
  box-shadow: 0 8px 24px rgba(0, 0, 0, 0.08);
}

.package-card:hover {
  transform: translateY(-6px);
  box-shadow: 0 12px 32px rgba(0, 0, 0, 0.12);
}

.package-card.featured {
  border: 2px solid var(--blue-400);
  background: linear-gradient(to bottom right, var(--white), var(--blue-100));
}

.popular-tag {
  position: absolute;
  top: -15px;
  left: 50%;
  transform: translateX(-50%);
  background: var(--blue-500);
  color: var(--white);
  padding: 0.75rem 1.5rem;
  border-radius: 25px;
  font-size: 0.8rem;
  font-weight: 600;
  box-shadow: 0 4px 12px rgba(33, 150, 243, 0.3);
}

.package-header {
  font-size: 1.75rem;
  font-weight: bold;
  margin-bottom: 1.5rem;
  color: var(--blue-500);
}

.package-price {
  font-size: 3rem;
  font-weight: bold;
  color: var(--blue-500);
  margin-bottom: 0.75rem;
  text-shadow: 0 2px 4px rgba(33, 150, 243, 0.2);
}

.package-credits {
  font-size: 1.25rem;
  color: var(--grey-500);
  margin-bottom: 2rem;
}

.package-features {
  list-style: none;
  margin-bottom: 2.5rem;
}

.package-features li {
  margin-bottom: 0.75rem;
  color: var(--grey-500);
  padding: 0.5rem;
  transition: all 0.3s ease;
}

.package-features li:hover {
  background-color: var(--grey-100);
  border-radius: 6px;
  transform: translateX(4px);
}

.purchase-btn {
  width: 100%;
  padding: 1rem 2rem;
  background-color: var(--blue-500);
  color: var(--white);
  border: none;
  border-radius: 8px;
  font-size: 1.1rem;
  font-weight: 600;
  cursor: pointer;
  transition: all 0.3s ease;
  box-shadow: 0 4px 12px rgba(33, 150, 243, 0.3);
}

.purchase-btn:hover {
  background-color: var(--blue-400);
  transform: translateY(-2px);
  box-shadow: 0 6px 16px rgba(33, 150, 243, 0.4);
}

.modal {
  display: none;
  position: fixed;
  top: 0;
  left: 0;
  width: 100%;
  height: 100%;
  background-color: rgba(0, 0, 0, 0.5);
  z-index: 1001;
  backdrop-filter: blur(4px);
}

.modal-content {
  background-color: var(--white);
  margin: 5% auto;
  padding: 2.5rem;
  width: 90%;
  max-width: 500px;
  border-radius: 12px;
  position: relative;
  box-shadow: 0 16px 32px rgba(0, 0, 0, 0.15);
  transform: translateY(20px);
  opacity: 0;
  animation: modalSlideIn 0.3s ease forwards;
}

@keyframes modalSlideIn {
  to {
    transform: translateY(0);
    opacity: 1;
  }
}

.close {
  position: absolute;
  right: 1.5rem;
  top: 1.5rem;
  font-size: 1.5rem;
  cursor: pointer;
  color: var(--grey-500);
  transition: all 0.3s ease;
  width: 32px;
  height: 32px;
  display: flex;
  align-items: center;
  justify-content: center;
  border-radius: 50%;
}

.close:hover {
  background-color: var(--grey-100);
  color: var(--error-red);
  transform: rotate(90deg);
}

.purchase-summary {
  background-color: var(--blue-100);
  padding: 1.5rem;
  border-radius: 8px;
  margin: 2rem 0;
}

.summary-item {
  display: flex;
  justify-content: space-between;
  margin-bottom: 0.75rem;
  padding: 0.5rem;
  transition: background-color 0.3s ease;
}

.summary-item:hover {
  background-color: var(--white);
  border-radius: 6px;
}

.form-group {
  margin-bottom: 1.5rem;
}

.form-group label {
  display: block;
  margin-bottom: 0.75rem;
  color: var(--grey-500);
  font-weight: 500;
}

.form-group input {
  width: 100%;
  padding: 0.875rem 1rem;
  border: 2px solid var(--grey-200);
  border-radius: 8px;
  font-size: 1rem;
  transition: all 0.3s ease;
}

.form-group input:hover {
  border-color: var(--blue-200);
}

.form-group input:focus {
  outline: none;
  border-color: var(--blue-400);
  box-shadow: 0 0 0 4px rgba(33, 150, 243, 0.1);
}

.form-row {
  display: grid;
  grid-template-columns: 2fr 1fr;
  gap: 1.5rem;
}

.submit-btn {
  width: 100%;
  padding: 1rem 2rem;
  background-color: var(--blue-500);
  color: var(--white);
  border: none;
  border-radius: 8px;
  font-size: 1.1rem;
  font-weight: 600;
  cursor: pointer;
  transition: all 0.3s ease;
  box-shadow: 0 4px 12px rgba(33, 150, 243, 0.3);
}

.submit-btn:hover {
  background-color: var(--blue-400);
  transform: translateY(-2px);
  box-shadow: 0 6px 16px rgba(33, 150, 243, 0.4);
}

.submit-btn:active {
  transform: translateY(0);
  box-shadow: 0 2px 8px rgba(33, 150, 243, 0.2);
}

.footer {
  background-color: var(--white);
  padding: 3rem 0 1rem;
  margin-top: auto;
}

.footer-content {
  max-width: 1200px;
  margin: 0 auto;
  padding: 0 20px;
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
  gap: 2rem;
}

.footer-section {
  display: flex;
  flex-direction: column;
  gap: 0.5rem;
}

.footer-section h3 {
  color: var(--black);
  margin-bottom: 1rem;
}

.footer-section a {
  color: var(--black);
  text-decoration: none;
  transition: color 0.3s;
}

.footer-section a:hover {
  color: var(--blue-400);
}

.social-links {
  display: flex;
  gap: 1rem;
}

.footer-bottom {
  text-align: center;
  margin-top: 2rem;
  padding-top: 1rem;
  border-top: 1px solid var(--grey-200);
}

@media (max-width: 900px) {
  .packages-container {
    grid-template-columns: repeat(2, 1fr);
  }

  .package-card {
    padding: 2rem;
  }

  .package-price {
    font-size: 2.5rem;
  }
}

@media (max-width: 600px) {
  .packages-container {
    grid-template-columns: 1fr;
  }

  .header-content {
    flex-direction: column;
    gap: 1rem;
  }

  .nav {
    flex-wrap: wrap;
    justify-content: center;
  }

  .nav a {
    padding: 0.5rem 0.75rem;
    font-size: 0.9rem;
  }

  .form-row {
    grid-template-columns: 1fr;
  }

  .modal-content {
    margin: 10% auto;
    padding: 1.5rem;
  }

  .package-header {
    font-size: 1.5rem;
  }

  .package-price {
    font-size: 2.25rem;
  }

  .package-credits {
    font-size: 1.1rem;
  }
}