/* ============================================
   The Rebuilder's Encyclopedia — Landing Page
   Design: Dark, industrial, serious reference work
   ============================================ */

/* --- CSS Variables --- */
:root {
  /* Base colors */
  --bg-dark: #1a1a1f;
  --bg-darker: #141418;
  --bg-card: #222228;
  --bg-card-hover: #2a2a32;
  --bg-elevated: #2c2c34;

  /* Text colors */
  --text-primary: #e8e4df;
  --text-secondary: #a8a4a0;
  --text-muted: #706c68;
  --text-inverse: #1a1a1f;

  /* Accent colors — warm industrial palette */
  --accent-rust: #c4652a;
  --accent-amber: #d4943a;
  --accent-copper: #b87333;
  --accent-warm: #e8a84c;
  --accent-glow: rgba(212, 148, 58, 0.15);

  /* Borders */
  --border-subtle: rgba(168, 164, 160, 0.1);
  --border-medium: rgba(168, 164, 160, 0.2);

  /* Typography */
  --font-serif: 'EB Garamond', Georgia, 'Times New Roman', serif;
  --font-sans: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', sans-serif;
  --font-mono: 'JetBrains Mono', 'Fira Code', monospace;

  /* Spacing */
  --section-pad: clamp(4rem, 8vw, 8rem);
  --container-max: 1200px;

  /* Transitions */
  --ease-out: cubic-bezier(0.16, 1, 0.3, 1);
}

/* --- Reset & Base --- */
*, *::before, *::after {
  margin: 0;
  padding: 0;
  box-sizing: border-box;
}

html {
  scroll-behavior: smooth;
  font-size: 16px;
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
}

body {
  font-family: var(--font-sans);
  background: var(--bg-dark);
  color: var(--text-primary);
  line-height: 1.7;
  overflow-x: hidden;
}

.container {
  max-width: var(--container-max);
  margin: 0 auto;
  padding: 0 clamp(1.5rem, 4vw, 3rem);
}

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

a {
  color: var(--accent-amber);
  text-decoration: none;
  transition: color 0.3s ease;
}

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

.hidden {
  display: none !important;
}

/* --- Section Labels & Titles --- */
.section-label {
  font-family: var(--font-mono);
  font-size: 0.75rem;
  font-weight: 500;
  text-transform: uppercase;
  letter-spacing: 0.2em;
  color: var(--accent-copper);
  margin-bottom: 1rem;
}

.section-title {
  font-family: var(--font-serif);
  font-size: clamp(1.75rem, 4vw, 2.75rem);
  font-weight: 600;
  color: var(--text-primary);
  margin-bottom: 1rem;
  line-height: 1.2;
}

.section-desc {
  font-size: 1.1rem;
  color: var(--text-secondary);
  max-width: 680px;
  margin-bottom: 3rem;
  line-height: 1.7;
}

/* --- Buttons --- */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  padding: 0.875rem 2rem;
  font-family: var(--font-sans);
  font-size: 0.95rem;
  font-weight: 600;
  border-radius: 4px;
  border: none;
  cursor: pointer;
  transition: all 0.3s var(--ease-out);
  text-decoration: none;
  letter-spacing: 0.02em;
}

.btn-primary {
  background: var(--accent-rust);
  color: #fff;
  box-shadow: 0 2px 12px rgba(196, 101, 42, 0.3);
}

.btn-primary:hover {
  background: var(--accent-amber);
  color: #fff;
  box-shadow: 0 4px 20px rgba(212, 148, 58, 0.4);
  transform: translateY(-1px);
}

.btn-secondary {
  background: transparent;
  color: var(--text-primary);
  border: 1px solid var(--border-medium);
}

.btn-secondary:hover {
  border-color: var(--accent-copper);
  color: var(--accent-warm);
  background: rgba(184, 115, 51, 0.08);
}

/* --- Navigation --- */
.nav {
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  z-index: 1000;
  padding: 1rem 0;
  transition: all 0.4s ease;
  background: transparent;
}

.nav.scrolled {
  background: rgba(20, 20, 24, 0.95);
  backdrop-filter: blur(12px);
  -webkit-backdrop-filter: blur(12px);
  border-bottom: 1px solid var(--border-subtle);
  padding: 0.6rem 0;
}

.nav-inner {
  max-width: var(--container-max);
  margin: 0 auto;
  padding: 0 clamp(1.5rem, 4vw, 3rem);
  display: flex;
  align-items: center;
  justify-content: space-between;
}

.nav-logo {
  font-family: var(--font-serif);
  font-size: 1.5rem;
  font-weight: 700;
  color: var(--accent-amber);
  text-decoration: none;
  letter-spacing: 0.05em;
}

.nav-links {
  display: flex;
  align-items: center;
  gap: 2rem;
}

.nav-links a {
  font-size: 0.875rem;
  font-weight: 500;
  color: var(--text-secondary);
  text-decoration: none;
  transition: color 0.3s ease;
  letter-spacing: 0.02em;
}

.nav-links a:hover {
  color: var(--text-primary);
}

.nav-cta {
  background: var(--accent-rust);
  color: #fff !important;
  padding: 0.5rem 1.25rem;
  border-radius: 4px;
  font-weight: 600 !important;
}

.nav-cta:hover {
  background: var(--accent-amber);
}

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

.nav-toggle span {
  display: block;
  width: 24px;
  height: 2px;
  background: var(--text-primary);
  transition: all 0.3s ease;
}

/* --- Hero --- */
.hero {
  min-height: 100vh;
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  position: relative;
  padding: 6rem 0 4rem;
  overflow: hidden;
}

.hero-bg-pattern {
  position: absolute;
  inset: 0;
  background:
    radial-gradient(ellipse 80% 60% at 50% 40%, rgba(196, 101, 42, 0.06) 0%, transparent 70%),
    radial-gradient(ellipse 60% 50% at 70% 60%, rgba(184, 115, 51, 0.04) 0%, transparent 60%);
  pointer-events: none;
}

.hero::before {
  content: '';
  position: absolute;
  top: 0;
  left: 0;
  right: 0;
  height: 1px;
  background: linear-gradient(90deg, transparent, var(--accent-copper), transparent);
  opacity: 0.3;
}

.hero-content {
  text-align: center;
  position: relative;
  z-index: 1;
}

.hero-publisher {
  font-family: var(--font-mono);
  font-size: 0.7rem;
  text-transform: uppercase;
  letter-spacing: 0.3em;
  color: var(--text-muted);
  margin-bottom: 2rem;
}

.hero-title {
  margin-bottom: 1.5rem;
}

.hero-title-main {
  display: block;
  font-family: var(--font-serif);
  font-size: clamp(2.5rem, 7vw, 5rem);
  font-weight: 700;
  line-height: 1.05;
  color: var(--text-primary);
  letter-spacing: -0.01em;
}

.hero-title-sub {
  display: block;
  font-family: var(--font-serif);
  font-size: clamp(1.1rem, 2.5vw, 1.75rem);
  font-weight: 400;
  font-style: italic;
  color: var(--accent-copper);
  margin-top: 0.75rem;
}

.hero-subtitle {
  font-family: var(--font-sans);
  font-size: clamp(1rem, 2vw, 1.25rem);
  color: var(--text-secondary);
  font-weight: 400;
  margin-bottom: 1.5rem;
  letter-spacing: 0.02em;
}

.hero-tagline {
  font-family: var(--font-sans);
  font-size: clamp(0.95rem, 1.5vw, 1.1rem);
  color: var(--text-muted);
  max-width: 600px;
  margin: 0 auto 2.5rem;
  line-height: 1.6;
}

.hero-cta {
  display: flex;
  gap: 1rem;
  justify-content: center;
  flex-wrap: wrap;
  margin-bottom: 3rem;
}

.hero-stats-mini {
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 1rem;
  flex-wrap: wrap;
  font-family: var(--font-mono);
  font-size: 0.8rem;
  color: var(--text-muted);
  letter-spacing: 0.05em;
}

.hero-stats-mini strong {
  color: var(--accent-amber);
  font-weight: 600;
}

.hero-stats-mini .divider {
  color: var(--border-medium);
}

.hero-scroll-indicator {
  position: absolute;
  bottom: 2rem;
  left: 50%;
  transform: translateX(-50%);
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 0.5rem;
  color: var(--text-muted);
  font-size: 0.75rem;
  letter-spacing: 0.15em;
  text-transform: uppercase;
  font-family: var(--font-mono);
  animation: float 3s ease-in-out infinite;
}

@keyframes float {
  0%, 100% { transform: translateX(-50%) translateY(0); }
  50% { transform: translateX(-50%) translateY(6px); }
}

/* --- Introduction --- */
.intro {
  padding: var(--section-pad) 0;
  border-bottom: 1px solid var(--border-subtle);
}

.intro-content {
  max-width: 780px;
}

.intro-text {
  font-family: var(--font-serif);
  font-size: clamp(1.15rem, 2vw, 1.35rem);
  line-height: 1.8;
  color: var(--text-secondary);
  margin-bottom: 1.5rem;
}

.intro-text strong {
  color: var(--text-primary);
}

.intro-text em {
  color: var(--accent-amber);
  font-style: italic;
}

/* --- Stages --- */
.stages {
  padding: var(--section-pad) 0;
  background: var(--bg-darker);
}

.stages-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(320px, 1fr));
  gap: 1.5rem;
}

.stage-card {
  background: var(--bg-card);
  border: 1px solid var(--border-subtle);
  border-radius: 6px;
  padding: 2rem;
  transition: all 0.4s var(--ease-out);
  position: relative;
  overflow: hidden;
}

.stage-card::before {
  content: '';
  position: absolute;
  top: 0;
  left: 0;
  right: 0;
  height: 2px;
  background: linear-gradient(90deg, var(--accent-rust), var(--accent-amber));
  opacity: 0;
  transition: opacity 0.4s ease;
}

.stage-card:hover {
  border-color: var(--border-medium);
  background: var(--bg-card-hover);
  transform: translateY(-2px);
  box-shadow: 0 8px 32px rgba(0, 0, 0, 0.3);
}

.stage-card:hover::before {
  opacity: 1;
}

.stage-header {
  margin-bottom: 1rem;
}

.stage-number {
  font-family: var(--font-mono);
  font-size: 0.7rem;
  text-transform: uppercase;
  letter-spacing: 0.2em;
  color: var(--accent-copper);
}

.stage-name {
  font-family: var(--font-serif);
  font-size: 1.5rem;
  font-weight: 600;
  color: var(--text-primary);
  margin: 0.25rem 0;
}

.stage-time {
  font-family: var(--font-mono);
  font-size: 0.75rem;
  color: var(--text-muted);
  letter-spacing: 0.05em;
}

.stage-desc {
  font-size: 0.95rem;
  color: var(--text-secondary);
  margin-bottom: 1.25rem;
  line-height: 1.6;
}

.stage-topics {
  list-style: none;
  display: flex;
  flex-wrap: wrap;
  gap: 0.5rem;
}

.stage-topics li {
  font-family: var(--font-mono);
  font-size: 0.72rem;
  color: var(--text-muted);
  background: rgba(168, 164, 160, 0.06);
  border: 1px solid var(--border-subtle);
  padding: 0.3rem 0.75rem;
  border-radius: 3px;
  letter-spacing: 0.02em;
}

.stage-card:hover .stage-topics li {
  border-color: var(--border-medium);
}

/* --- Sample Content --- */
.sample {
  padding: var(--section-pad) 0;
  border-bottom: 1px solid var(--border-subtle);
}

.sample-content {
  max-width: 800px;
}

.sample-excerpt {
  position: relative;
  background: var(--bg-darker);
  border: 1px solid var(--border-subtle);
  border-left: 3px solid var(--accent-rust);
  border-radius: 0 6px 6px 0;
  padding: 2.5rem;
  margin-bottom: 2rem;
}

.sample-chapter-label {
  font-family: var(--font-mono);
  font-size: 0.72rem;
  text-transform: uppercase;
  letter-spacing: 0.15em;
  color: var(--accent-copper);
  margin-bottom: 1.5rem;
}

.sample-text {
  border: none;
  padding: 0;
  margin: 0;
}

.sample-text p {
  font-family: var(--font-serif);
  font-size: 1.1rem;
  line-height: 1.85;
  color: var(--text-secondary);
  margin-bottom: 1.25rem;
}

.sample-text p:first-child::first-letter {
  font-size: 3.5rem;
  float: left;
  line-height: 1;
  margin-right: 0.15em;
  margin-top: 0.05em;
  color: var(--accent-amber);
  font-weight: 600;
}

.sample-text em {
  color: var(--accent-warm);
}

.sample-fade {
  position: absolute;
  bottom: 0;
  left: 0;
  right: 0;
  height: 80px;
  background: linear-gradient(transparent, var(--bg-darker));
  pointer-events: none;
}

.sample-cta {
  display: flex;
  align-items: center;
  gap: 2rem;
  flex-wrap: wrap;
}

.sample-cta-text {
  flex: 1;
  min-width: 240px;
  font-size: 1rem;
  color: var(--text-secondary);
}

.sample-cta-text em {
  color: var(--accent-amber);
  font-style: italic;
}

/* --- Stats --- */
.stats {
  padding: var(--section-pad) 0;
  background: var(--bg-darker);
}

.stats-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(280px, 1fr));
  gap: 1.5rem;
}

.stat-card {
  background: var(--bg-card);
  border: 1px solid var(--border-subtle);
  border-radius: 6px;
  padding: 2rem;
  text-align: center;
  transition: all 0.4s var(--ease-out);
}

.stat-card:hover {
  border-color: var(--accent-copper);
  box-shadow: 0 0 30px var(--accent-glow);
  transform: translateY(-2px);
}

.stat-number {
  display: block;
  font-family: var(--font-serif);
  font-size: clamp(2.5rem, 5vw, 3.5rem);
  font-weight: 700;
  color: var(--accent-amber);
  line-height: 1.1;
  margin-bottom: 0.25rem;
}

.stat-label {
  display: block;
  font-family: var(--font-sans);
  font-size: 1rem;
  font-weight: 600;
  color: var(--text-primary);
  margin-bottom: 0.5rem;
  text-transform: uppercase;
  letter-spacing: 0.1em;
}

.stat-context {
  display: block;
  font-size: 0.85rem;
  color: var(--text-muted);
  line-height: 1.4;
}

/* --- Products --- */
.products {
  padding: var(--section-pad) 0;
  border-bottom: 1px solid var(--border-subtle);
}

.products-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(280px, 1fr));
  gap: 1.5rem;
}

.product-card {
  background: var(--bg-card);
  border: 1px solid var(--border-subtle);
  border-radius: 6px;
  padding: 2rem;
  transition: all 0.4s var(--ease-out);
}

.product-card:hover {
  border-color: var(--border-medium);
  background: var(--bg-card-hover);
}

.product-featured {
  border-color: var(--accent-rust);
  background: linear-gradient(135deg, var(--bg-card) 0%, rgba(196, 101, 42, 0.05) 100%);
  grid-column: 1 / -1;
}

.product-featured:hover {
  border-color: var(--accent-amber);
}

.product-badge {
  display: inline-block;
  font-family: var(--font-mono);
  font-size: 0.7rem;
  text-transform: uppercase;
  letter-spacing: 0.2em;
  color: var(--accent-amber);
  background: rgba(212, 148, 58, 0.1);
  padding: 0.3rem 0.75rem;
  border-radius: 3px;
  margin-bottom: 1rem;
}

.product-name {
  font-family: var(--font-serif);
  font-size: 1.35rem;
  font-weight: 600;
  color: var(--text-primary);
  margin-bottom: 0.75rem;
}

.product-desc {
  font-size: 0.95rem;
  color: var(--text-secondary);
  line-height: 1.6;
}

/* --- About --- */
.about {
  padding: var(--section-pad) 0;
  background: var(--bg-darker);
}

.about-content {
  max-width: 780px;
}

.about-content p {
  font-family: var(--font-serif);
  font-size: 1.1rem;
  line-height: 1.8;
  color: var(--text-secondary);
  margin-bottom: 1.5rem;
}

.about-content strong {
  color: var(--text-primary);
}

.about-content em {
  color: var(--accent-amber);
}

.about-publisher {
  margin-top: 2.5rem;
  padding-top: 2rem;
  border-top: 1px solid var(--border-subtle);
}

.about-publisher p {
  font-family: var(--font-sans) !important;
  margin-bottom: 0.25rem !important;
}

.about-publisher-sub {
  font-size: 0.95rem !important;
  color: var(--text-muted) !important;
}

/* --- Signup --- */
.signup {
  padding: var(--section-pad) 0;
  border-bottom: 1px solid var(--border-subtle);
}

.signup-content {
  max-width: 600px;
  margin: 0 auto;
  text-align: center;
}

.signup-title {
  font-family: var(--font-serif);
  font-size: clamp(1.75rem, 4vw, 2.5rem);
  font-weight: 600;
  color: var(--text-primary);
  margin-bottom: 1rem;
}

.signup-desc {
  font-size: 1.05rem;
  color: var(--text-secondary);
  margin-bottom: 2rem;
  line-height: 1.6;
}

.signup-form-row {
  display: flex;
  gap: 0.75rem;
  margin-bottom: 1rem;
}

.signup-input {
  flex: 1;
  padding: 0.875rem 1.25rem;
  font-family: var(--font-sans);
  font-size: 1rem;
  background: var(--bg-darker);
  border: 1px solid var(--border-medium);
  border-radius: 4px;
  color: var(--text-primary);
  outline: none;
  transition: border-color 0.3s ease;
}

.signup-input::placeholder {
  color: var(--text-muted);
}

.signup-input:focus {
  border-color: var(--accent-copper);
  box-shadow: 0 0 0 3px var(--accent-glow);
}

.signup-btn {
  white-space: nowrap;
}

.signup-note {
  font-size: 0.8rem;
  color: var(--text-muted);
}

/* --- Footer --- */
.footer {
  padding: 4rem 0 2rem;
  background: var(--bg-darker);
}

.footer-grid {
  display: grid;
  grid-template-columns: 2fr 1fr 1fr;
  gap: 3rem;
  margin-bottom: 3rem;
}

.footer-title {
  font-family: var(--font-serif);
  font-size: 1.25rem;
  font-weight: 600;
  color: var(--text-primary);
  margin-bottom: 0.25rem;
}

.footer-tagline {
  font-family: var(--font-serif);
  font-style: italic;
  color: var(--accent-copper);
  font-size: 0.95rem;
  margin-bottom: 1rem;
}

.footer-copy {
  font-size: 0.8rem;
  color: var(--text-muted);
}

.footer-links h4,
.footer-social h4 {
  font-family: var(--font-mono);
  font-size: 0.7rem;
  text-transform: uppercase;
  letter-spacing: 0.2em;
  color: var(--text-muted);
  margin-bottom: 1rem;
}

.footer-links a,
.footer-social a {
  display: block;
  font-size: 0.9rem;
  color: var(--text-secondary);
  margin-bottom: 0.6rem;
  transition: color 0.3s ease;
}

.footer-links a:hover,
.footer-social a:hover {
  color: var(--accent-amber);
}

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

.footer-bottom p {
  font-family: var(--font-mono);
  font-size: 0.75rem;
  color: var(--text-muted);
  letter-spacing: 0.1em;
}

/* --- Animations --- */
.fade-in {
  opacity: 0;
  transform: translateY(20px);
  transition: opacity 0.6s var(--ease-out), transform 0.6s var(--ease-out);
}

.fade-in.visible {
  opacity: 1;
  transform: translateY(0);
}

/* --- Responsive --- */
@media (max-width: 768px) {
  .nav-links {
    display: none;
    position: absolute;
    top: 100%;
    left: 0;
    right: 0;
    background: rgba(20, 20, 24, 0.98);
    backdrop-filter: blur(12px);
    flex-direction: column;
    padding: 1.5rem 2rem;
    gap: 1rem;
    border-bottom: 1px solid var(--border-subtle);
  }

  .nav-links.open {
    display: flex;
  }

  .nav-toggle {
    display: flex;
  }

  .nav-cta {
    text-align: center;
    width: 100%;
  }

  .hero-cta {
    flex-direction: column;
    align-items: center;
  }

  .hero-cta .btn {
    width: 100%;
    max-width: 300px;
  }

  .hero-stats-mini .divider {
    display: none;
  }

  .hero-stats-mini {
    gap: 0.5rem 1.5rem;
  }

  .stages-grid {
    grid-template-columns: 1fr;
  }

  .stats-grid {
    grid-template-columns: repeat(2, 1fr);
  }

  .products-grid {
    grid-template-columns: 1fr;
  }

  .product-featured {
    grid-column: 1;
  }

  .footer-grid {
    grid-template-columns: 1fr;
    gap: 2rem;
  }

  .signup-form-row {
    flex-direction: column;
  }

  .sample-excerpt {
    padding: 1.5rem;
  }

  .sample-cta {
    flex-direction: column;
    gap: 1.25rem;
  }
}

@media (max-width: 480px) {
  .stats-grid {
    grid-template-columns: 1fr;
  }

  .hero-title-main {
    font-size: 2.25rem;
  }
}

/* --- Selection --- */
::selection {
  background: rgba(196, 101, 42, 0.3);
  color: var(--text-primary);
}

/* --- Scrollbar --- */
::-webkit-scrollbar {
  width: 8px;
}

::-webkit-scrollbar-track {
  background: var(--bg-darker);
}

::-webkit-scrollbar-thumb {
  background: var(--bg-elevated);
  border-radius: 4px;
}

::-webkit-scrollbar-thumb:hover {
  background: var(--text-muted);
}