:root {
  --bg-dark: #05080c;
  --bg-darker: #020305;
  --panel-bg: rgba(20, 25, 30, 0.4);
  --panel-border: rgba(0, 255, 157, 0.15);
  --accent: #00ff9d;
  --accent-glow: 0 0 20px rgba(0, 255, 157, 0.4);
  --text-main: #ffffff;
  --text-sub: #9ca3af;
  --font-heading: 'Outfit', sans-serif;
  --font-body: 'Inter', sans-serif;
}

html {
  scroll-behavior: smooth;
}

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

body {
  background-color: var(--bg-darker);
  color: var(--text-main);
  font-family: var(--font-body);
  line-height: 1.6;
  overflow-x: hidden;
  -webkit-font-smoothing: antialiased;
}

/* Futuristic Ambient Background */
.ambient-glow {
  position: fixed;
  top: -20vh;
  left: -20vw;
  width: 100vw;
  height: 100vw;
  max-width: 800px;
  max-height: 800px;
  background: radial-gradient(circle at center, rgba(0, 255, 157, 0.08) 0%, transparent 70%);
  z-index: -1;
  animation: float 20s ease-in-out infinite alternate;
}

.ambient-glow.orb-2 {
  top: auto;
  bottom: -20vh;
  left: auto;
  right: -20vw;
  background: radial-gradient(circle at center, rgba(0, 184, 255, 0.05) 0%, transparent 70%);
  animation-delay: -10s;
}

@keyframes float {
  0% { transform: translate(0, 0) scale(1); }
  100% { transform: translate(10%, 15%) scale(1.1); }
}

/* Container */
.container {
  max-width: 600px; /* Optimized for mobile-first scrolling */
  margin: 0 auto;
  padding: 40px 20px;
  display: flex;
  flex-direction: column;
  gap: 40px;
}

/* Glass Panel Base */
.glass-panel {
  background: var(--panel-bg);
  backdrop-filter: blur(12px);
  -webkit-backdrop-filter: blur(12px);
  border: 1px solid var(--panel-border);
  border-radius: 16px;
  padding: 24px;
  box-shadow: 0 8px 32px rgba(0, 0, 0, 0.3);
  transition: transform 0.3s ease, border-color 0.3s ease, box-shadow 0.3s ease;
}

.glass-panel:hover {
  border-color: rgba(0, 255, 157, 0.3);
  box-shadow: 0 12px 40px rgba(0, 255, 157, 0.05);
}

/* Header */
header {
  text-align: center;
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 24px;
  padding-top: 20px;
}

.cover-wrapper {
  position: relative;
  width: 200px;
  max-width: 100%;
  perspective: 1000px;
}

.book-cover {
  width: 100%;
  height: auto;
  border-radius: 8px;
  box-shadow: 0 20px 40px rgba(0, 0, 0, 0.5), 0 0 30px rgba(0, 255, 157, 0.2);
  transform: rotateY(0deg) translateZ(0);
  transition: transform 0.5s ease;
  z-index: 2;
  position: relative;
}

.cover-wrapper:hover .book-cover {
  transform: translateY(-5px) rotateY(-5deg) scale(1.02);
}

.glow-effect {
  position: absolute;
  top: 50%;
  left: 50%;
  transform: translate(-50%, -50%);
  width: 120%;
  height: 120%;
  background: radial-gradient(circle at center, rgba(0,255,157,0.3) 0%, transparent 60%);
  z-index: 1;
  opacity: 0;
  transition: opacity 0.5s ease;
}

.cover-wrapper:hover .glow-effect {
  opacity: 1;
}

.main-title {
  font-family: var(--font-heading);
  font-size: 28px;
  font-weight: 800;
  line-height: 1.2;
  letter-spacing: -0.5px;
  margin-top: 10px;
}

.main-title .highlight {
  display: block;
  background: linear-gradient(135deg, #00ff9d 0%, #00b8ff 100%);
  -webkit-background-clip: text;
  background-clip: text;
  -webkit-text-fill-color: transparent;
  font-size: 34px;
  margin-top: 4px;
}

/* Pricing Card */
.pricing-card {
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 8px;
  width: 100%;
  max-width: 300px;
  position: relative;
  overflow: hidden;
}

.pricing-card::before {
  content: '';
  position: absolute;
  top: 0; left: 0; right: 0; height: 2px;
  background: linear-gradient(90deg, transparent, var(--accent), transparent);
  opacity: 0.5;
}

.price-old {
  font-size: 18px;
  text-decoration: line-through;
  color: var(--text-sub);
  font-weight: 500;
}

.price-new {
  font-family: var(--font-heading);
  font-size: 42px;
  font-weight: 800;
  color: var(--text-main);
  line-height: 1;
  text-shadow: 0 0 15px rgba(0, 255, 157, 0.3);
}

.price-badge {
  font-size: 12px;
  text-transform: uppercase;
  letter-spacing: 1px;
  color: var(--accent);
  border: 1px solid var(--accent);
  padding: 4px 12px;
  border-radius: 20px;
  font-weight: 600;
  background: rgba(0, 255, 157, 0.05);
  margin-top: 4px;
}

/* Text Sections */
.description-section p {
  margin-bottom: 16px;
  font-size: 16px;
  color: #c9d1d9;
}

.description-section p:last-child {
  margin-bottom: 0;
}

.highlight-text {
  font-size: 18px !important;
  font-weight: 600;
  color: var(--text-main) !important;
  border-left: 3px solid var(--accent);
  padding-left: 16px;
  margin-left: -2px;
}

.section-title {
  font-family: var(--font-heading);
  font-size: 24px;
  font-weight: 600;
  margin-bottom: 20px;
  text-align: center;
}

/* Features Grid */
.features-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(130px, 1fr));
  gap: 16px;
}

.feature-item {
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  text-align: center;
  padding: 20px 12px;
  gap: 12px;
  cursor: default;
}

.feature-item .icon {
  font-size: 28px;
  filter: drop-shadow(0 0 10px rgba(255,255,255,0.2));
}

.feature-item .text {
  font-size: 14px;
  font-weight: 500;
  line-height: 1.3;
}

.summary-text {
  font-size: 16px;
  color: #c9d1d9;
}

.neon-text {
  color: var(--text-main);
  font-weight: 600;
  text-shadow: 0 0 10px rgba(0,255,157,0.3);
}

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

/* Reviews Carousel */
.reviews-section {
  position: relative;
}

.reviews-slider {
  width: 100%;
  overflow: hidden;
  padding: 10px 0;
}

.reviews-track {
  display: flex;
  transition: transform 0.5s cubic-bezier(0.25, 1, 0.5, 1);
  will-change: transform;
}

.review-card {
  min-width: 100%;
  flex: 0 0 100%;
  box-sizing: border-box;
  opacity: 0.5;
  transform: scale(0.95);
  transition: opacity 0.5s ease, transform 0.5s ease;
  margin-right: 16px; 
}

.review-card.active {
  opacity: 1;
  transform: scale(1);
}

.review-header {
  display: flex;
  align-items: center;
  gap: 12px;
  margin-bottom: 12px;
}

.avatar {
  width: 44px;
  height: 44px;
  border-radius: 50%;
  object-fit: cover;
  border: 2px solid rgba(0, 255, 157, 0.3);
}

.review-meta {
  display: flex;
  flex-direction: column;
}

.review-meta .name {
  font-weight: 600;
  font-size: 15px;
}

.review-meta .stars {
  color: #FEC337;
  font-size: 14px;
  letter-spacing: 2px;
}

.review-body {
  font-size: 14px;
  color: #a0aab2;
  font-style: italic;
  line-height: 1.5;
}

.slider-nav {
  display: flex;
  justify-content: center;
  gap: 16px;
  margin-top: 20px;
}

.nav-btn {
  background: var(--panel-bg);
  border: 1px solid var(--panel-border);
  color: var(--text-main);
  width: 44px;
  height: 44px;
  border-radius: 50%;
  display: flex;
  align-items: center;
  justify-content: center;
  cursor: pointer;
  font-size: 18px;
  transition: all 0.2s ease;
  padding: 0;
}

.nav-btn:hover {
  background: rgba(0, 255, 157, 0.1);
  border-color: var(--accent);
  box-shadow: var(--accent-glow);
}

/* Checkout Section */
.flex-col {
  display: flex;
  flex-direction: column;
}

.checkout-form {
  display: flex;
  flex-direction: column;
  gap: 16px;
  position: relative;
  overflow: hidden;
}

.checkout-form::before {
  content: '';
  position: absolute;
  top: 0; left: 0; right: 0; height: 1px;
  background: linear-gradient(90deg, transparent, var(--accent), transparent);
}

.input-group input {
  width: 100%;
  background: rgba(0, 0, 0, 0.3);
  border: 1px solid rgba(255, 255, 255, 0.1);
  border-radius: 12px;
  padding: 16px 20px;
  color: var(--text-main);
  font-family: var(--font-body);
  font-size: 16px;
  transition: border-color 0.3s ease, box-shadow 0.3s ease;
  outline: none;
}

.input-group input:focus {
  border-color: var(--accent);
  box-shadow: inset 0 0 10px rgba(0,255,157,0.1), 0 0 10px rgba(0,255,157,0.1);
}

.input-group input::placeholder {
  color: rgba(255,255,255,0.3);
}

.cta-button {
  position: relative;
  background: linear-gradient(135deg, #00ff9d 0%, #00b8ff 100%);
  color: #000;
  border: none;
  border-radius: 12px;
  padding: 18px 24px;
  font-family: var(--font-heading);
  font-size: 18px;
  font-weight: 800;
  cursor: pointer;
  overflow: hidden;
  transition: transform 0.2s ease, box-shadow 0.2s ease;
  margin-top: 8px;
}

.cta-button:hover {
  transform: translateY(-2px);
  box-shadow: 0 10px 25px rgba(0, 255, 157, 0.4);
}

.cta-button:active {
  transform: translateY(0);
}

.btn-text {
  position: relative;
  z-index: 2;
}

.btn-glow {
  position: absolute;
  top: -50%;
  left: -50%;
  width: 200%;
  height: 200%;
  background: radial-gradient(circle, rgba(255,255,255,0.3) 0%, transparent 50%);
  z-index: 1;
  opacity: 0;
  transition: opacity 0.3s;
}

.cta-button:hover .btn-glow {
  opacity: 1;
  animation: rotateBtnGlow 3s linear infinite;
}

@keyframes rotateBtnGlow {
  0% { transform: rotate(0deg); }
  100% { transform: rotate(360deg); }
}

.secure-checkout {
  text-align: center;
  font-size: 13px;
  color: var(--text-sub);
  margin-top: 8px;
  font-weight: 500;
}

/* Media Queries */
@media (min-width: 640px) {
  .features-grid {
    grid-template-columns: repeat(2, 1fr);
  }
}