/* ============================================
   ShopK0lateral — Design System v1
   DESIGN.md tokens → CSS variables
   Dark neón: #0a0a0f · #00f0ff · #7c3aed · #ff6b35
   ============================================ */

:root {
  /* Backgrounds */
  --bg-deep: #0a0a0f;
  --bg-card: #111118;
  --bg-surface: #1a1a25;
  
  /* Text */
  --text-primary: #e0e0e0;
  --text-secondary: #999;
  --text-muted: #666;
  
  /* Accents */
  --accent-blue: #00f0ff;
  --accent-violet: #7c3aed;
  --accent-orange: #ff6b35;
  --accent-green: #22d65e;
  
  /* Gradients */
  --gradient-hero: linear-gradient(135deg, #00f0ff11, #7c3aed22);
  --gradient-card: linear-gradient(135deg, #7c3aed11, #00f0ff11);
  --gradient-violet: linear-gradient(135deg, #7c3aed, #00f0ff);
  
  /* Borders */
  --border-subtle: #ffffff11;
  --border-accent: #00f0ff22;
  
  /* Typography */
  --font: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', sans-serif;
  --font-mono: 'JetBrains Mono', 'Fira Code', monospace;
  
  /* Spacing */
  --space-xs: 4px;
  --space-sm: 8px;
  --space-md: 16px;
  --space-lg: 24px;
  --space-xl: 32px;
  --space-xxl: 48px;
  
  /* Rounded */
  --radius-sm: 6px;
  --radius-md: 10px;
  --radius-lg: 16px;
  --radius-full: 999px;
  
  /* Shadows */
  --shadow-sm: 0 2px 8px rgba(0,0,0,0.3);
  --shadow-md: 0 4px 20px rgba(0,0,0,0.3);
  --shadow-lg: 0 8px 40px rgba(0,0,0,0.4);
  
  /* Navbar */
  --navbar-height: 64px;
  
  /* Layout */
  --max-width: 1100px;
  --content-padding: 20px;
}

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

html { scroll-behavior: smooth; }

body {
  font-family: var(--font);
  background: var(--bg-deep);
  color: var(--text-primary);
  line-height: 1.6;
  min-height: 100vh;
  -webkit-font-smoothing: antialiased;
}

.container {
  max-width: var(--max-width);
  margin: 0 auto;
  padding: 0 var(--content-padding);
}

/* ========== NAVBAR ========== */
.navbar {
  position: fixed;
  top: 0;
  width: 100%;
  z-index: 1000;
  height: var(--navbar-height);
  background: rgba(10,10,15,0.85);
  backdrop-filter: blur(20px);
  -webkit-backdrop-filter: blur(20px);
  border-bottom: 1px solid var(--border-subtle);
  display: flex;
  align-items: center;
}

.navbar .container {
  display: flex;
  justify-content: space-between;
  align-items: center;
  width: 100%;
}

.navbar .logo {
  font-size: 1.5rem;
  font-weight: 800;
  background: var(--gradient-violet);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
  text-decoration: none;
}

.navbar .logo span { color: var(--accent-blue); -webkit-text-fill-color: var(--accent-blue); }

.nav-links {
  display: flex;
  gap: var(--space-lg);
  list-style: none;
  align-items: center;
}

.nav-links a {
  color: var(--text-muted);
  text-decoration: none;
  font-size: 0.9rem;
  font-weight: 500;
  transition: color 0.2s;
}

.nav-links a:hover { color: var(--accent-blue); }

.menu-toggle {
  display: none;
  flex-direction: column;
  gap: 5px;
  cursor: pointer;
  padding: 4px;
}

.menu-toggle span {
  width: 24px;
  height: 2px;
  background: var(--text-primary);
  border-radius: 2px;
  transition: 0.3s;
}

/* ========== HERO ========== */
.hero {
  background: var(--gradient-hero);
  padding: calc(var(--navbar-height) + var(--space-xxl)) 0 var(--space-xxl);
  text-align: center;
  min-height: 60vh;
  display: flex;
  align-items: center;
}

.hero h1 {
  font-size: 2.5rem;
  font-weight: 800;
  line-height: 1.1;
  margin-bottom: var(--space-md);
  background: var(--gradient-violet);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
}

.hero p {
  color: var(--text-secondary);
  font-size: 1.1rem;
  max-width: 600px;
  margin: 0 auto var(--space-lg);
}

/* ========== BOOK CARDS ========== */
.books-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
  gap: var(--space-lg);
  padding: var(--space-xxl) 0;
}

.book-card {
  background: var(--bg-card);
  border: 1px solid var(--border-subtle);
  border-radius: var(--radius-md);
  padding: var(--space-lg);
  transition: all 0.25s ease;
  position: relative;
}

.book-card:hover {
  border-color: var(--border-accent);
  transform: translateY(-4px);
  box-shadow: var(--shadow-md);
}

.book-card .icon { font-size: 2.5rem; margin-bottom: var(--space-sm); }

.book-card h3 {
  font-size: 1.25rem;
  font-weight: 600;
  margin-bottom: var(--space-sm);
}

.book-card .desc {
  color: var(--text-secondary);
  font-size: 0.9rem;
  margin-bottom: var(--space-md);
  line-height: 1.5;
}

.book-card .price {
  font-size: 1.5rem;
  font-weight: 700;
  color: var(--accent-blue);
  margin-bottom: var(--space-sm);
}

.book-card .badges { display: flex; gap: var(--space-xs); flex-wrap: wrap; margin-bottom: var(--space-md); }

.badge-product {
  background: var(--accent-blue);
  color: var(--bg-deep);
  border-radius: var(--radius-sm);
  padding: 2px 10px;
  font-size: 0.75rem;
  font-weight: 700;
}

.badge-sale {
  background: var(--accent-orange);
  color: var(--bg-deep);
  border-radius: var(--radius-sm);
  padding: 2px 10px;
  font-size: 0.75rem;
  font-weight: 700;
}

.badge-free {
  background: var(--accent-green);
  color: var(--bg-deep);
  border-radius: var(--radius-sm);
  padding: 2px 10px;
  font-size: 0.75rem;
  font-weight: 700;
}

/* ========== BUTTONS ========== */
.btn {
  display: inline-block;
  padding: 12px 24px;
  border-radius: var(--radius-md);
  font-weight: 600;
  font-family: var(--font);
  font-size: 0.95rem;
  text-decoration: none;
  cursor: pointer;
  transition: all 0.2s;
  border: none;
  text-align: center;
}

.btn-primary {
  background: var(--accent-violet);
  color: white;
}

.btn-primary:hover { background: #8b5cf6; transform: translateY(-1px); }

.btn-secondary {
  background: transparent;
  color: var(--accent-blue);
  border: 1px solid var(--border-accent);
}

.btn-secondary:hover { border-color: var(--accent-blue); }

.btn-orange {
  background: var(--accent-orange);
  color: white;
}

.btn-orange:hover { background: #ff7b4a; transform: translateY(-1px); }

.btn-full { width: 100%; }

/* ========== NEWSLETTER ========== */
.newsletter-section {
  background: var(--gradient-hero);
  border: 1px solid var(--border-subtle);
  border-radius: var(--radius-lg);
  padding: var(--space-xl);
  margin: var(--space-lg) 0 var(--space-xxl);
  text-align: center;
}

.newsletter-section h2 {
  font-size: 1.5rem;
  margin-bottom: var(--space-sm);
}

.newsletter-section p {
  color: var(--text-secondary);
  margin-bottom: var(--space-md);
}

.newsletter-form {
  display: flex;
  flex-direction: column;
  gap: var(--space-sm);
  max-width: 500px;
  margin: 0 auto;
}

.newsletter-form input[type="email"],
.newsletter-form input[type="text"] {
  background: var(--bg-surface);
  border: 1px solid var(--border-subtle);
  border-radius: var(--radius-sm);
  padding: 12px 16px;
  color: var(--text-primary);
  font-family: var(--font);
  font-size: 0.95rem;
  width: 100%;
  transition: border 0.2s;
}

.newsletter-form input:focus {
  outline: none;
  border-color: var(--accent-blue);
}

.checkbox-group {
  display: flex;
  flex-direction: column;
  gap: var(--space-sm);
  text-align: left;
  padding: var(--space-sm) 0;
}

.checkbox-group label {
  display: flex;
  align-items: flex-start;
  gap: var(--space-sm);
  font-size: 0.8rem;
  color: var(--text-secondary);
  cursor: pointer;
}

.checkbox-group input[type="checkbox"] {
  margin-top: 2px;
  accent-color: var(--accent-violet);
}

/* ========== FOOTER ========== */
footer {
  padding: var(--space-xl) 0;
  border-top: 1px solid var(--border-subtle);
  text-align: center;
  color: var(--text-muted);
  font-size: 0.8rem;
}

footer a { color: var(--accent-violet); text-decoration: none; }

footer a:hover { color: var(--accent-blue); }

/* ========== PRICE SECTION ========== */
.price-section {
  display: flex;
  align-items: baseline;
  gap: var(--space-sm);
  margin-bottom: var(--space-sm);
}

.old-price { text-decoration: line-through; color: var(--text-muted); font-size: 0.9rem; }

/* ========== SECTION TITLE ========== */
.section-title {
  text-align: center;
  margin-bottom: var(--space-lg);
}

.section-title h2 {
  font-size: 1.75rem;
  font-weight: 700;
}

.section-title p {
  color: var(--text-secondary);
  margin-top: var(--space-xs);
}

/* ========== BANNER ========== */
.banner-pack {
  background: var(--gradient-violet);
  border-radius: var(--radius-md);
  padding: var(--space-lg);
  text-align: center;
  margin: var(--space-lg) 0;
}

.banner-pack h3 { font-size: 1.3rem; color: white; margin-bottom: var(--space-xs); }

.banner-pack p { font-size: 0.9rem; color: rgba(255,255,255,0.8); margin-bottom: var(--space-md); }

.banner-pack .price { font-size: 1.8rem; font-weight: 800; color: white; }

.banner-pack .old-price { color: rgba(255,255,255,0.5); }

/* ========== RESPONSIVE ========== */
@media (max-width: 768px) {
  .hero h1 { font-size: 1.8rem; }
  .hero p { font-size: 1rem; }
  .books-grid { grid-template-columns: 1fr; }
  .nav-links { 
    display: none; 
    position: absolute; 
    top: var(--navbar-height);
    left: 0;
    width: 100%;
    background: rgba(10,10,15,0.95);
    backdrop-filter: blur(20px);
    flex-direction: column;
    padding: var(--space-md);
    border-bottom: 1px solid var(--border-subtle);
  }
  .nav-links.active { display: flex; }
  .menu-toggle { display: flex; }
  .newsletter-section { padding: var(--space-lg); }
}

/* ========== UTILITY ========== */
.text-center { text-align: center; }
.mt-sm { margin-top: var(--space-sm); }
.mt-md { margin-top: var(--space-md); }
.mt-lg { margin-top: var(--space-lg); }
.mb-sm { margin-bottom: var(--space-sm); }
.mb-md { margin-bottom: var(--space-md); }
.mb-lg { margin-bottom: var(--space-lg); }
.gap-sm { gap: var(--space-sm); }
.gap-md { gap: var(--space-md); }
.flex-center { display: flex; justify-content: center; align-items: center; }