/* ============================================
   InterFact — Railroad-Inspired Landing Page
   ============================================ */

/* --- Custom Properties --- */
:root {
  --bg-primary: #0C0E12;
  --bg-section-alt: #141820;
  --bg-surface: #1C2028;
  --bg-surface-hover: #242a34;
  --accent: #E85D2C;
  --accent-hover: #d14e20;
  --accent-glow: rgba(232, 93, 44, 0.25);
  --accent-gradient: linear-gradient(135deg, #E85D2C, #F59E0B);
  --signal-green: #22C55E;
  --signal-red: #EF4444;
  --text-primary: #F1F5F9;
  --text-secondary: #94A3B8;
  --text-muted: #64748B;
  --border: #2D3748;
  --border-light: rgba(255,255,255,0.06);
  --font-heading: 'DM Sans', sans-serif;
  --font-body: 'Inter', sans-serif;
  --font-mono: 'JetBrains Mono', monospace;
  --nav-height: 64px;
  --max-width: 1200px;
  --radius: 12px;
  --radius-sm: 8px;
  --transition: 0.3s ease;
}

/* --- Reset --- */
*, *::before, *::after { box-sizing: border-box; margin: 0; padding: 0; }
html { scroll-behavior: smooth; scroll-padding-top: var(--nav-height); }
body {
  font-family: var(--font-body);
  font-size: 16px;
  line-height: 1.7;
  color: var(--text-primary);
  background: var(--bg-primary);
  -webkit-font-smoothing: antialiased;
  overflow-x: hidden;
}
img { max-width: 100%; height: auto; display: block; }
a { color: var(--accent); text-decoration: none; transition: color var(--transition); }
a:hover { color: #F59E0B; }
ul { list-style: none; }

/* --- Utility --- */
.container { max-width: var(--max-width); margin: 0 auto; padding: 0 24px; }
.eyebrow {
  font-family: var(--font-mono);
  font-size: 0.75rem;
  font-weight: 500;
  letter-spacing: 0.12em;
  text-transform: uppercase;
  color: var(--accent);
  display: flex;
  align-items: center;
  gap: 12px;
  margin-bottom: 16px;
}
.eyebrow::before {
  content: '';
  width: 32px;
  height: 2px;
  background: var(--accent);
  flex-shrink: 0;
}
.section-heading {
  font-family: var(--font-heading);
  font-size: clamp(2rem, 4vw, 3rem);
  font-weight: 700;
  letter-spacing: -0.02em;
  line-height: 1.15;
  margin-bottom: 20px;
}
.section-subtext {
  color: var(--text-secondary);
  font-size: 1.1rem;
  max-width: 600px;
  margin-bottom: 48px;
}

/* --- Scroll Animations --- */
.fade-up {
  opacity: 0;
  transform: translateY(28px);
  transition: opacity 0.7s ease, transform 0.7s ease;
}
.fade-up.visible {
  opacity: 1;
  transform: translateY(0);
}

/* --- Navigation --- */
.nav {
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  height: var(--nav-height);
  z-index: 1000;
  transition: background var(--transition), box-shadow var(--transition);
}
.nav.scrolled {
  background: rgba(12, 14, 18, 0.92);
  backdrop-filter: blur(16px);
  -webkit-backdrop-filter: blur(16px);
  box-shadow: 0 1px 0 var(--border);
}
.nav-inner {
  max-width: var(--max-width);
  margin: 0 auto;
  padding: 0 24px;
  height: 100%;
  display: flex;
  align-items: center;
  justify-content: space-between;
}
.nav-brand {
  display: flex;
  align-items: center;
  gap: 12px;
  text-decoration: none;
}
.nav-brand img {
  width: 36px;
  height: 36px;
  border-radius: 50%;
}
.nav-brand span {
  font-family: var(--font-heading);
  font-size: 1.25rem;
  font-weight: 700;
  color: var(--text-primary);
  letter-spacing: -0.01em;
}
.nav-links {
  display: flex;
  align-items: center;
  gap: 32px;
}
.nav-links a {
  font-size: 0.875rem;
  font-weight: 500;
  color: var(--text-secondary);
  letter-spacing: 0.02em;
  transition: color var(--transition);
}
.nav-links a:hover { color: var(--text-primary); }
.nav-cta {
  font-size: 0.875rem !important;
  font-weight: 600 !important;
  color: var(--bg-primary) !important;
  background: var(--accent-gradient);
  padding: 8px 20px;
  border-radius: 6px;
  transition: transform var(--transition), box-shadow var(--transition) !important;
}
.nav-cta:hover {
  transform: translateY(-1px);
  box-shadow: 0 4px 16px var(--accent-glow);
  color: var(--bg-primary) !important;
}

/* Hamburger (mobile) */
.nav-hamburger {
  display: none;
  flex-direction: column;
  gap: 5px;
  background: none;
  border: none;
  cursor: pointer;
  padding: 4px;
}
.nav-hamburger span {
  display: block;
  width: 24px;
  height: 2px;
  background: var(--text-primary);
  border-radius: 2px;
  transition: transform var(--transition), opacity var(--transition);
}
.nav-hamburger.active span:nth-child(1) { transform: translateY(7px) rotate(45deg); }
.nav-hamburger.active span:nth-child(2) { opacity: 0; }
.nav-hamburger.active span:nth-child(3) { transform: translateY(-7px) rotate(-45deg); }

.mobile-menu {
  display: none;
  position: fixed;
  top: var(--nav-height);
  left: 0;
  right: 0;
  bottom: 0;
  background: rgba(12, 14, 18, 0.98);
  backdrop-filter: blur(16px);
  z-index: 999;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  gap: 32px;
}
.mobile-menu.open { display: flex; }
.mobile-menu a {
  font-family: var(--font-heading);
  font-size: 1.5rem;
  font-weight: 600;
  color: var(--text-primary);
}

/* --- Hero --- */
.hero {
  min-height: 100vh;
  display: flex;
  align-items: center;
  position: relative;
  overflow: hidden;
  padding-top: var(--nav-height);
}
.hero-bg {
  position: absolute;
  inset: 0;
  z-index: 0;
  overflow: hidden;
}
/* Perspective railroad tracks */
.hero-bg::before {
  content: '';
  position: absolute;
  bottom: 0;
  left: 50%;
  width: 200%;
  height: 120%;
  transform: translateX(-50%);
  background:
    linear-gradient(to bottom, transparent 40%, rgba(45, 55, 72, 0.08) 100%),
    linear-gradient(175.5deg, transparent 49.6%, var(--border) 49.6%, var(--border) 49.75%, transparent 49.75%),
    linear-gradient(184.5deg, transparent 49.6%, var(--border) 49.6%, var(--border) 49.75%, transparent 49.75%);
  opacity: 0.4;
}
/* Signal light decorations */
.hero-bg::after {
  content: '';
  position: absolute;
  top: 20%;
  right: 12%;
  width: 300px;
  height: 300px;
  background:
    radial-gradient(circle at 50% 20%, var(--signal-red) 0%, transparent 4%),
    radial-gradient(circle at 50% 50%, var(--accent) 0%, transparent 4%),
    radial-gradient(circle at 50% 80%, var(--signal-green) 0%, transparent 4%),
    radial-gradient(circle at 50% 20%, rgba(239, 68, 68, 0.15) 0%, transparent 12%),
    radial-gradient(circle at 50% 50%, rgba(232, 93, 44, 0.15) 0%, transparent 12%),
    radial-gradient(circle at 50% 80%, rgba(34, 197, 94, 0.15) 0%, transparent 12%);
  opacity: 0.6;
}
.hero .container {
  position: relative;
  z-index: 1;
  padding-top: 80px;
  padding-bottom: 80px;
}
.hero-content { max-width: 680px; }
.hero h1 {
  font-family: var(--font-heading);
  font-size: clamp(2.75rem, 6vw, 4.5rem);
  font-weight: 700;
  letter-spacing: -0.03em;
  line-height: 1.05;
  margin-bottom: 24px;
}
.hero h1 .highlight {
  background: var(--accent-gradient);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
}
.hero-subtitle {
  font-size: clamp(1.1rem, 2vw, 1.3rem);
  color: var(--text-secondary);
  line-height: 1.6;
  margin-bottom: 40px;
  max-width: 520px;
}
.hero-actions {
  display: flex;
  gap: 16px;
  flex-wrap: wrap;
  margin-bottom: 48px;
}
.btn-primary {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  font-family: var(--font-heading);
  font-size: 1rem;
  font-weight: 600;
  color: var(--bg-primary);
  background: var(--accent-gradient);
  padding: 14px 32px;
  border-radius: 8px;
  border: none;
  cursor: pointer;
  transition: transform var(--transition), box-shadow var(--transition);
}
.btn-primary:hover {
  transform: translateY(-2px);
  box-shadow: 0 8px 32px var(--accent-glow);
  color: var(--bg-primary);
}
.btn-ghost {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  font-family: var(--font-heading);
  font-size: 1rem;
  font-weight: 600;
  color: var(--text-primary);
  background: transparent;
  padding: 14px 32px;
  border-radius: 8px;
  border: 1px solid var(--border);
  cursor: pointer;
  transition: border-color var(--transition), background var(--transition);
}
.btn-ghost:hover {
  border-color: var(--text-secondary);
  background: rgba(255,255,255,0.03);
  color: var(--text-primary);
}
.hero-badge {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  font-family: var(--font-mono);
  font-size: 0.8rem;
  color: var(--text-secondary);
  letter-spacing: 0.04em;
}
.pulse-dot {
  width: 8px;
  height: 8px;
  background: var(--signal-green);
  border-radius: 50%;
  position: relative;
}
.pulse-dot::after {
  content: '';
  position: absolute;
  inset: -4px;
  border-radius: 50%;
  background: var(--signal-green);
  animation: pulse 2s ease-in-out infinite;
}
@keyframes pulse {
  0%, 100% { opacity: 0.4; transform: scale(1); }
  50% { opacity: 0; transform: scale(2); }
}


/* --- Crossing Stripe Accent --- */
.stripe-accent {
  height: 4px;
  background: repeating-linear-gradient(
    -45deg,
    var(--accent),
    var(--accent) 6px,
    transparent 6px,
    transparent 12px
  );
  border-radius: 2px;
  max-width: var(--max-width);
  margin: 32px auto;
  padding: 0 24px;
  opacity: 0.6;
}

/* --- Sections --- */
section {
  padding: 96px 0;
}
section.alt-bg {
  background: var(--bg-section-alt);
}
/* Blueprint grid overlay */
section.grid-bg {
  background-image:
    linear-gradient(rgba(45, 55, 72, 0.04) 1px, transparent 1px),
    linear-gradient(90deg, rgba(45, 55, 72, 0.04) 1px, transparent 1px);
  background-size: 40px 40px;
}

/* --- Problem Section --- */
.problem-grid {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 64px;
  align-items: center;
}
.problem-image {
  border-radius: var(--radius);
  overflow: hidden;
  border: 1px solid rgba(239, 68, 68, 0.2);
  box-shadow: 0 0 40px rgba(239, 68, 68, 0.08);
}
.problem-image img {
  width: 100%;
  display: block;
}
.stat-cards {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 16px;
  margin-top: 32px;
}
.stat-card {
  background: var(--bg-surface);
  border: 1px solid var(--border);
  border-radius: var(--radius-sm);
  padding: 20px;
  text-align: center;
}
.stat-card .stat-value {
  font-family: var(--font-mono);
  font-size: 1.5rem;
  font-weight: 700;
  color: var(--accent);
  margin-bottom: 4px;
}
.stat-card .stat-label {
  font-size: 0.8rem;
  color: var(--text-secondary);
}

/* --- Solution Section --- */
.feature-grid {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: 24px;
  margin-bottom: 64px;
}
.feature-card {
  background: var(--bg-surface);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  overflow: hidden;
  transition: transform var(--transition), box-shadow var(--transition), border-color var(--transition);
}
.feature-card:hover {
  transform: translateY(-4px);
  box-shadow: 0 12px 40px rgba(0,0,0,0.3);
  border-color: rgba(232, 93, 44, 0.3);
}
.feature-card-img {
  width: 100%;
  height: 350px;
  overflow: hidden;
  background: var(--bg-primary);
}
.feature-card-img img {
  width: 100%;
  height: 100%;
  object-fit: contain;
}
.feature-card-body {
  padding: 24px;
}
.feature-card-body h3 {
  font-family: var(--font-heading);
  font-size: 1.15rem;
  font-weight: 600;
  margin-bottom: 8px;
}
.feature-card-body p {
  color: var(--text-secondary);
  font-size: 0.9rem;
  line-height: 1.6;
}
.showcase {
  border-radius: var(--radius);
  overflow: hidden;
  border: 1px solid var(--border);
  box-shadow: 0 4px 24px rgba(0,0,0,0.2);
}
.showcase img { width: 100%; display: block; }
.showcase-caption {
  font-size: 0.85rem;
  color: var(--text-muted);
  text-align: center;
  margin-top: 12px;
}

/* --- How It Works --- */
.steps {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 32px;
  position: relative;
}
/* Horizontal track line connecting steps */
.steps::before {
  content: '';
  position: absolute;
  top: 48px;
  left: 15%;
  right: 15%;
  height: 2px;
  background: var(--border);
}
.step {
  text-align: center;
  position: relative;
  z-index: 1;
}
.step-number {
  width: 64px;
  height: 64px;
  border-radius: 50%;
  background: var(--bg-surface);
  border: 2px solid var(--accent);
  display: inline-flex;
  align-items: center;
  justify-content: center;
  font-family: var(--font-mono);
  font-size: 1.25rem;
  font-weight: 700;
  color: var(--accent);
  margin-bottom: 24px;
  position: relative;
}
.step-number::after {
  content: '';
  position: absolute;
  inset: -6px;
  border-radius: 50%;
  border: 1px solid rgba(232, 93, 44, 0.15);
}
.step-icon {
  display: block;
  margin: 0 auto 12px;
  color: var(--text-secondary);
}
.step h3 {
  font-family: var(--font-heading);
  font-size: 1.1rem;
  font-weight: 600;
  margin-bottom: 8px;
}
.step p {
  color: var(--text-secondary);
  font-size: 0.9rem;
  max-width: 260px;
  margin: 0 auto;
}

/* --- Stats Section --- */
.stats-counters {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 32px;
  margin-bottom: 64px;
}
.counter {
  text-align: center;
}
.counter-value {
  font-family: var(--font-mono);
  font-size: clamp(2rem, 4vw, 3rem);
  font-weight: 700;
  color: var(--text-primary);
  line-height: 1.2;
  margin-bottom: 8px;
  text-shadow: 0 0 24px var(--accent-glow);
}
.counter-label {
  font-size: 0.85rem;
  color: var(--text-secondary);
}
.dashboard-frame {
  background: var(--bg-surface);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 8px;
  box-shadow: 0 8px 40px rgba(0,0,0,0.3);
}
.dashboard-frame img {
  border-radius: var(--radius-sm);
  width: 100%;
}
.dashboard-grid {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 24px;
}

/* --- Benefits Section --- */
.benefits-grid {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: 20px;
}
.benefit-item {
  display: flex;
  align-items: flex-start;
  gap: 16px;
  padding: 20px;
  border-radius: var(--radius-sm);
  background: var(--bg-surface);
  border: 1px solid var(--border);
  transition: border-color var(--transition);
}
.benefit-item:hover {
  border-color: rgba(34, 197, 94, 0.3);
}
.benefit-dot {
  width: 10px;
  height: 10px;
  background: var(--signal-green);
  border-radius: 50%;
  flex-shrink: 0;
  margin-top: 7px;
  box-shadow: 0 0 8px rgba(34, 197, 94, 0.4);
}
.benefit-item h4 {
  font-family: var(--font-heading);
  font-size: 0.95rem;
  font-weight: 600;
  margin-bottom: 4px;
}
.benefit-item p {
  color: var(--text-secondary);
  font-size: 0.85rem;
  line-height: 1.5;
}

/* --- CTA Section --- */
.cta-section {
  text-align: center;
  padding: 96px 0;
}
.cta-section .section-heading {
  max-width: 600px;
  margin-left: auto;
  margin-right: auto;
}
.cta-section .section-subtext {
  margin-left: auto;
  margin-right: auto;
}
.cta-contact {
  margin-top: 48px;
  color: var(--text-secondary);
  font-size: 0.95rem;
}
.cta-contact a {
  font-weight: 500;
}
.social-links {
  display: flex;
  justify-content: center;
  gap: 16px;
  margin-top: 24px;
}
.social-links a {
  display: flex;
  align-items: center;
  justify-content: center;
  width: 40px;
  height: 40px;
  border-radius: 50%;
  border: 1px solid var(--border);
  color: var(--text-secondary);
  transition: border-color var(--transition), color var(--transition);
}
.social-links a:hover {
  border-color: var(--accent);
  color: var(--accent);
}
.social-links svg {
  width: 18px;
  height: 18px;
}

/* --- Footer --- */
.footer {
  padding: 32px 0;
  border-top: 1px solid var(--border);
  text-align: center;
  font-size: 0.8rem;
  color: var(--text-muted);
}
.footer a { color: var(--text-secondary); }
.footer a:hover { color: var(--accent); }

/* --- Responsive --- */
@media (max-width: 1024px) {
  .problem-grid { grid-template-columns: 1fr; gap: 40px; }
  .feature-grid { grid-template-columns: 1fr 1fr; }
  .stats-counters { grid-template-columns: repeat(2, 1fr); }
  .dashboard-grid { grid-template-columns: 1fr; }
}

@media (max-width: 768px) {
  section { padding: 64px 0; }
  .nav-links { display: none; }
  .nav-hamburger { display: flex; }
  .hero h1 { font-size: 2.5rem; }
  .hero .container { padding-top: 40px; padding-bottom: 40px; }
  .hero-bg::after { display: none; }
  .feature-grid { grid-template-columns: 1fr; }
  .steps {
    grid-template-columns: 1fr;
    gap: 48px;
  }
  .steps::before {
    top: 0;
    bottom: 0;
    left: 32px;
    right: auto;
    width: 2px;
    height: auto;
  }
  .step { text-align: left; padding-left: 80px; }
  .step-number {
    position: absolute;
    left: 0;
    top: 0;
    width: 48px;
    height: 48px;
    font-size: 1rem;
  }
  .stats-counters { grid-template-columns: repeat(2, 1fr); gap: 24px; }
  .benefits-grid { grid-template-columns: 1fr; }
  .track-divider { padding: 32px 0; }
  .track-divider-inner { height: 56px; }
}

@media (max-width: 480px) {
  .hero h1 { font-size: 2rem; }
  .hero-actions { flex-direction: column; }
  .btn-primary, .btn-ghost { width: 100%; justify-content: center; }
  .stat-cards { grid-template-columns: 1fr; }
  .stats-counters { grid-template-columns: 1fr 1fr; }
}

/* --- Reduced Motion --- */
@media (prefers-reduced-motion: reduce) {
  *, *::before, *::after {
    animation-duration: 0.01ms !important;
    transition-duration: 0.01ms !important;
  }
  .fade-up { opacity: 1; transform: none; }
  html { scroll-behavior: auto; }
}