body {
  margin: 0;
  font-family: Arial, sans-serif;
  background: #1a252f;
  color: #ffffff;
  scroll-behavior: smooth;
}

.container {
  max-width: 1200px;
  margin: 0 auto;
  padding: 0 20px;
}

/* Header */
header {
  background: #0f151a;
  padding: 20px 0;
  position: sticky;
  top: 0;
  z-index: 100;
}

header .container {
  display: flex;
  justify-content: space-between;
  align-items: center;
}

header h1 {
  font-size: 24px;
  margin: 0;
}

.btn {
  background: #f1c40f;
  color: #0f151a;
  padding: 10px 20px;
  border-radius: 25px;
  text-decoration: none;
  font-weight: bold;
  transition: background 0.3s;
}

.btn:hover {
  background: #d4ac0d;
}

.btn-large {
  padding: 15px 30px;
  font-size: 18px;
}

/* Hero */
.hero {
  background: linear-gradient(rgba(0, 0, 0, 0.7), rgba(0, 0, 0, 0.7)), url('https://images.unsplash.com/photo-1516321315098-34d6b6a94a5b?ixlib=rb-4.0.3&auto=format&fit=crop&w=1920&q=80');
  background-size: cover;
  background-position: center;
  padding: 80px 0;
  text-align: center;
}

.hero h2 {
  font-size: 48px;
  margin-bottom: 20px;
}

.hero p {
  font-size: 20px;
  max-width: 700px;
  margin: 0 auto 30px;
}

/* Features */
.features {
  background: #22303c;
  padding: 60px 0;
}

.features h3 {
  font-size: 36px;
  text-align: center;
  margin-bottom: 40px;
}

.feature-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
  gap: 20px;
}

.feature {
  background: #2c3e50;
  padding: 20px;
  border-radius: 8px;
  text-align: center;
}

.feature h4 {
  font-size: 20px;
  margin-bottom: 15px;
}

.feature p {
  font-size: 16px;
}

/* Testimonials */
.testimonials {
  padding: 60px 0;
}

.testimonials h3 {
  font-size: 36px;
  text-align: center;
  margin-bottom: 40px;
}

.testimonial-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
  gap: 20px;
}

.testimonial {
  background: #22303c;
  padding: 20px;
  border-radius: 8px;
}

.testimonial .quote {
  font-style: italic;
  margin-bottom: 15px;
}

.testimonial .author {
  font-weight: bold;
}

/* Payment */
.payment {
  padding: 60px 0;
  text-align: center;
}

.payment h3 {
  font-size: 36px;
  margin-bottom: 20px;
}

.payment p {
  font-size: 18px;
  margin-bottom: 30px;
}

#payment-form {
  background: #22303c;
  padding: 30px;
  border-radius: 8px;
  max-width: 600px;
  margin: 0 auto;
  box-shadow: 0 4px 6px rgba(0, 0, 0, 0.2);
}

#payment-element {
  margin-bottom: 20px;
}

.payment-message {
  color: #e74c3c;
  font-size: 16px;
  text-align: center;
  margin-top: 20px;
  display: none;
}

.payment-message.show {
  display: block;
}

/* Footer */
footer {
  background: #0f151a;
  padding: 20px 0;
  text-align: center;
}

footer p {
  margin: 0;
}

.footer-links a {
  color: #f1c40f;
  margin: 0 10px;
  text-decoration: none;
}

.footer-links a:hover {
  text-decoration: underline;
}

/* Responsive */
@media (max-width: 768px) {
  header h1 {
    font-size: 20px;
  }

  .hero h2 {
    font-size: 36px;
  }

  .hero p {
    font-size: 18px;
  }

  .features h3,
  .testimonials h3,
  .payment h3 {
    font-size: 28px;
  }

  .btn-large {
    padding: 12px 25px;
    font-size: 16px;
  }
}