*,
*::before,
*::after {
  box-sizing: border-box;
}

body {
  margin: 0;
  font-family: system-ui, -apple-system, BlinkMacSystemFont, "Segoe UI", sans-serif;
  background: radial-gradient(circle at top left, #1b1b3a 0, #050514 55%, #02010a 100%);
  color: #f5f5ff;
  line-height: 1.6;
}

img {
  max-width: 100%;
  display: block;
}

h1, h2, h3 {
  margin-top: 0;
}

a {
  color: inherit;
  text-decoration: none;
}

.hero {
  padding: 3.5rem 1.5rem 4rem;
}

.hero-inner {
  max-width: 1120px;
  margin: 0 auto;
  display: flex;
  gap: 3rem;
  align-items: center;
  justify-content: space-between;
  flex-wrap: wrap;
}

.hero-text {
  flex: 1 1 340px;
  min-width: 0;
}

.hero-image {
  flex: 0 0 340px;
  display: flex;
  justify-content: center;
}

.badge {
  text-transform: uppercase;
  letter-spacing: 0.16em;
  font-size: 0.75rem;
  color: #c5c9ff;
  margin-bottom: 0.75rem;
}

h1 {
  font-size: clamp(2.2rem, 4vw, 3rem);
  font-weight: 800;
  line-height: 1.1;
}

.neon-pink {
  color: #ff4bcb;
  text-shadow: 0 0 18px rgba(255, 75, 203, 0.7);
}

.neon-yellow {
  color: #ffe94b;
  text-shadow: 0 0 18px rgba(255, 233, 75, 0.7);
}

.neon-cyan {
  color: #3fe8ff;
  text-shadow: 0 0 18px rgba(63, 232, 255, 0.7);
}

.subtitle {
  text-transform: uppercase;
  letter-spacing: 0.22em;
  font-size: 0.8rem;
  color: #6cf0ff;
  margin-top: 0.9rem;
}

.lead {
  margin-top: 1rem;
  max-width: 36rem;
  color: #dde1ff;
}

.hero-cta {
  margin-top: 1.8rem;
}

.btn-primary {
  display: inline-block;
  padding: 0.9rem 1.8rem;
  border-radius: 999px;
  background: linear-gradient(90deg, #ff4bcb, #ffe94b, #3fe8ff);
  background-size: 200% 100%;
  color: #050514;
  font-weight: 700;
  font-size: 0.95rem;
  text-transform: uppercase;
  letter-spacing: 0.12em;
  border: none;
  cursor: pointer;
  transition: transform 0.15s ease, box-shadow 0.15s ease, background-position 0.3s ease;
  box-shadow: 0 0 25px rgba(255, 75, 203, 0.6);
}

.btn-primary:hover {
  transform: translateY(-1px);
  background-position: 100% 0;
  box-shadow: 0 0 32px rgba(63, 232, 255, 0.9);
}

.btn-large {
  padding-inline: 2.4rem;
  font-size: 1rem;
}

.small-hint {
  font-size: 0.8rem;
  color: #b9bfff;
  margin-top: 0.7rem;
}

.cover-card {
  background: radial-gradient(circle at top, rgba(255, 255, 255, 0.14), rgba(5, 5, 20, 0.9));
  padding: 1rem;
  border-radius: 1.8rem;
  box-shadow:
    0 0 30px rgba(0, 0, 0, 0.7),
    0 0 60px rgba(63, 232, 255, 0.3);
  max-width: 320px;
}

.section {
  padding: 3.5rem 1.5rem;
}

.section.light {
  background: radial-gradient(circle at top, rgba(111, 117, 255, 0.15), rgba(5, 5, 20, 0.96));
}

.section.dark {
  background: #050514;
}

.section.cta-section {
  text-align: center;
  background: radial-gradient(circle at center, rgba(255, 75, 203, 0.1), #050514);
}

.container {
  max-width: 960px;
  margin: 0 auto;
}

.section h2 {
  font-size: 1.7rem;
  margin-bottom: 0.8rem;
}

.section p {
  color: #d9ddff;
  max-width: 56rem;
}

.chapters-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(230px, 1fr));
  gap: 1.5rem;
  margin-top: 2rem;
}

.chapter {
  background: linear-gradient(145deg, rgba(18, 20, 60, 0.95), rgba(4, 4, 20, 0.98));
  border-radius: 1.1rem;
  padding: 1.2rem 1.2rem 1.3rem;
  box-shadow: 0 0 18px rgba(0, 0, 0, 0.7);
  border: 1px solid rgba(99, 216, 255, 0.18);
}

.chapter.highlight {
  border-color: rgba(255, 233, 75, 0.6);
  box-shadow: 0 0 26px rgba(255, 233, 75, 0.3);
}

.chapter-icon {
  font-size: 1.5rem;
  margin-bottom: 0.4rem;
}

.chapter h3 {
  font-size: 1rem;
  margin-bottom: 0.5rem;
}

.chapter p {
  font-size: 0.9rem;
  color: #e1e5ff;
}

.two-cols {
  display: grid;
  grid-template-columns: minmax(0, 1.1fr) minmax(0, 1fr);
  gap: 2rem;
  align-items: flex-start;
  margin-top: 1.4rem;
}

.feature-list {
  padding-left: 1.1rem;
  margin: 0 0 0.8rem;
}

.feature-list li {
  margin-bottom: 0.4rem;
}

.center {
  text-align: center;
}

.center p {
  margin-left: auto;
  margin-right: auto;
}

.footer {
  border-top: 1px solid rgba(111, 117, 255, 0.4);
  padding: 1.6rem 1.5rem 2rem;
  background: #02010a;
  font-size: 0.8rem;
  color: #9ea4d5;
}

.footer-inner {
  display: flex;
  justify-content: space-between;
  align-items: center;
  gap: 1rem;
  max-width: 960px;
  margin: 0 auto;
}

.footer-links a {
  color: #c7ccff;
  font-size: 0.8rem;
}

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

/* Responsive */

@media (max-width: 900px) {
  .hero-inner {
    flex-direction: column;
    align-items: flex-start;
  }

  .hero-image {
    order: -1;
    width: 100%;
    justify-content: flex-start;
  }

  .cover-card {
    margin-bottom: 1.8rem;
  }
}

@media (max-width: 640px) {
  .hero {
    padding-top: 2.2rem;
  }

  h1 {
    font-size: 2rem;
  }

  .two-cols {
    grid-template-columns: minmax(0, 1fr);
  }
}