:root {
  --bg-primary: #0a0a0f;
  --bg-secondary: #111118;
  --bg-card: #16161f;
  --bg-card-hover: #1c1c28;
  --text-primary: #e8e8ed;
  --text-secondary: #8a8a9a;
  --text-muted: #5a5a6a;
  --accent: #f97316;
  --accent-glow: rgba(249, 115, 22, 0.15);
  --accent-soft: #fb923c;
  --border: #222233;
  --border-accent: rgba(249, 115, 22, 0.3);
  --radius: 12px;
  --font-display: 'Space Grotesk', sans-serif;
  --font-body: 'DM Sans', sans-serif;
}

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

html { scroll-behavior: smooth; }

body {
  background: var(--bg-primary);
  color: var(--text-primary);
  font-family: var(--font-body);
  font-size: 16px;
  line-height: 1.6;
  -webkit-font-smoothing: antialiased;
}

/* NAV */
.nav {
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  z-index: 100;
  padding: 1.25rem 2rem;
  background: rgba(10, 10, 15, 0.85);
  backdrop-filter: blur(12px);
  border-bottom: 1px solid var(--border);
}
.nav-inner {
  max-width: 1200px;
  margin: 0 auto;
  display: flex;
  align-items: center;
  justify-content: space-between;
}
.nav-logo {
  font-family: var(--font-display);
  font-size: 1.4rem;
  font-weight: 700;
  letter-spacing: -0.02em;
}
.logo-pipe { color: var(--text-primary); }
.logo-fuse { color: var(--accent); }

/* HERO */
.hero {
  padding: 10rem 2rem 6rem;
  max-width: 1200px;
  margin: 0 auto;
}
.hero-grid {
  display: grid;
  grid-template-columns: 1.2fr 0.8fr;
  gap: 4rem;
  align-items: center;
}
.hero-tag {
  font-family: var(--font-display);
  font-size: 0.85rem;
  font-weight: 600;
  text-transform: uppercase;
  letter-spacing: 0.12em;
  color: var(--accent);
  margin-bottom: 1.5rem;
}
.hero-headline {
  font-family: var(--font-display);
  font-size: clamp(2.5rem, 5vw, 4rem);
  font-weight: 700;
  line-height: 1.1;
  letter-spacing: -0.03em;
  color: var(--text-primary);
  margin-bottom: 1.5rem;
}
.hero-sub {
  font-size: 1.15rem;
  color: var(--text-secondary);
  max-width: 480px;
  line-height: 1.7;
}

/* Flow Diagram Visual */
.hero-visual {
  display: flex;
  align-items: center;
  justify-content: center;
}
.flow-diagram {
  display: flex;
  align-items: center;
  gap: 0;
}
.flow-node {
  font-family: var(--font-display);
  font-size: 0.85rem;
  font-weight: 600;
  padding: 1rem 1.5rem;
  border-radius: var(--radius);
  background: var(--bg-card);
  border: 1px solid var(--border);
  color: var(--text-primary);
  text-align: center;
  position: relative;
}
.node-trigger { border-color: var(--border-accent); box-shadow: 0 0 20px var(--accent-glow); }
.node-action { background: var(--accent); color: #0a0a0f; border-color: var(--accent); }
.node-result { border-color: rgba(34, 197, 94, 0.3); box-shadow: 0 0 20px rgba(34, 197, 94, 0.1); }
.flow-line {
  width: 40px;
  height: 2px;
  background: linear-gradient(90deg, var(--accent), var(--text-muted));
  opacity: 0.5;
}

/* PROBLEM */
.problem {
  padding: 6rem 2rem;
  background: var(--bg-secondary);
}
.problem-inner {
  max-width: 1200px;
  margin: 0 auto;
}
.problem-label, .how-label, .tiers-label {
  font-family: var(--font-display);
  font-size: 0.8rem;
  font-weight: 600;
  text-transform: uppercase;
  letter-spacing: 0.15em;
  color: var(--accent);
  margin-bottom: 1rem;
}
.problem-headline, .how-headline, .tiers-headline {
  font-family: var(--font-display);
  font-size: clamp(1.8rem, 3.5vw, 2.5rem);
  font-weight: 700;
  letter-spacing: -0.02em;
  color: var(--text-primary);
  margin-bottom: 3rem;
}
.problem-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 2rem;
}
.problem-card {
  padding: 2rem;
  background: var(--bg-card);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  transition: border-color 0.2s;
}
.problem-card:hover {
  border-color: var(--border-accent);
}
.problem-number {
  font-family: var(--font-display);
  font-size: 2.5rem;
  font-weight: 700;
  color: var(--accent);
  margin-bottom: 0.75rem;
  line-height: 1;
}
.problem-card p {
  color: var(--text-secondary);
  font-size: 0.95rem;
  line-height: 1.6;
}

/* HOW */
.how {
  padding: 6rem 2rem;
}
.how-inner {
  max-width: 1200px;
  margin: 0 auto;
}
.how-steps {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 2.5rem;
}
.how-step {
  padding: 2.5rem 2rem;
  border-left: 2px solid var(--border);
  transition: border-color 0.3s;
}
.how-step:hover {
  border-color: var(--accent);
}
.step-marker {
  font-family: var(--font-display);
  font-size: 0.8rem;
  font-weight: 700;
  color: var(--accent);
  margin-bottom: 1.25rem;
  letter-spacing: 0.05em;
}
.how-step h3 {
  font-family: var(--font-display);
  font-size: 1.25rem;
  font-weight: 600;
  color: var(--text-primary);
  margin-bottom: 0.75rem;
}
.how-step p {
  color: var(--text-secondary);
  font-size: 0.95rem;
  line-height: 1.7;
}

/* TIERS */
.tiers {
  padding: 6rem 2rem;
  background: var(--bg-secondary);
}
.tiers-inner {
  max-width: 1200px;
  margin: 0 auto;
}
.tiers-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 2rem;
}
.tier-card {
  padding: 2.5rem 2rem;
  background: var(--bg-card);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  transition: transform 0.2s, border-color 0.2s;
}
.tier-card:hover {
  transform: translateY(-4px);
  border-color: var(--border-accent);
}
.tier-featured {
  border-color: var(--accent);
  box-shadow: 0 0 30px var(--accent-glow);
  position: relative;
}
.tier-name {
  font-family: var(--font-display);
  font-size: 0.85rem;
  font-weight: 600;
  text-transform: uppercase;
  letter-spacing: 0.1em;
  color: var(--text-muted);
  margin-bottom: 1rem;
}
.tier-price {
  font-family: var(--font-display);
  font-size: 2rem;
  font-weight: 700;
  color: var(--text-primary);
  margin-bottom: 1.25rem;
  line-height: 1.2;
}
.tier-price span {
  font-size: 0.85rem;
  font-weight: 500;
  color: var(--text-muted);
}
.tier-desc {
  color: var(--text-secondary);
  font-size: 0.95rem;
  line-height: 1.7;
}

/* CLOSING */
.closing {
  padding: 8rem 2rem;
  text-align: center;
}
.closing-inner {
  max-width: 720px;
  margin: 0 auto;
}
.closing-headline {
  font-family: var(--font-display);
  font-size: clamp(1.8rem, 3.5vw, 2.8rem);
  font-weight: 700;
  letter-spacing: -0.02em;
  color: var(--text-primary);
  margin-bottom: 1.5rem;
  line-height: 1.2;
}
.closing-sub {
  color: var(--text-secondary);
  font-size: 1.1rem;
  line-height: 1.8;
  max-width: 600px;
  margin: 0 auto;
}

/* NAV CTAs */
.nav-ctas { display: flex; align-items: center; gap: 0.75rem; }
.nav-login { color: var(--text-secondary); text-decoration: none; font-size: 0.875rem; font-weight: 500; transition: color 0.15s; }
.nav-login:hover { color: var(--text-primary); }
.nav-signup {
  background: var(--accent);
  color: #0a0a0f;
  font-family: var(--font-display);
  font-weight: 700;
  font-size: 0.85rem;
  padding: 0.5rem 1rem;
  border-radius: 8px;
  text-decoration: none;
  transition: opacity 0.15s;
}
.nav-signup:hover { opacity: 0.9; }

/* HERO CTAs */
.hero-ctas { display: flex; gap: 0.875rem; align-items: center; margin-top: 2rem; flex-wrap: wrap; }
.hero-btn-primary {
  display: inline-flex;
  align-items: center;
  background: var(--accent);
  color: #0a0a0f;
  font-family: var(--font-display);
  font-weight: 700;
  font-size: 1rem;
  padding: 0.75rem 1.5rem;
  border-radius: 10px;
  text-decoration: none;
  transition: opacity 0.15s, transform 0.15s;
}
.hero-btn-primary:hover { opacity: 0.9; transform: translateY(-1px); }
.hero-btn-ghost {
  display: inline-flex;
  align-items: center;
  color: var(--text-secondary);
  font-size: 0.95rem;
  text-decoration: none;
  transition: color 0.15s;
  border: 1px solid var(--border);
  padding: 0.75rem 1.25rem;
  border-radius: 10px;
}
.hero-btn-ghost:hover { color: var(--text-primary); border-color: var(--border-accent); }

/* FOOTER */
.footer {
  padding: 3rem 2rem;
  border-top: 1px solid var(--border);
}
.footer-inner {
  max-width: 1200px;
  margin: 0 auto;
  display: flex;
  align-items: center;
  justify-content: space-between;
}
.footer-brand {
  font-family: var(--font-display);
  font-size: 1.1rem;
  font-weight: 700;
}
.footer-note {
  color: var(--text-muted);
  font-size: 0.85rem;
}

/* RESPONSIVE */
@media (max-width: 768px) {
  .hero { padding: 7rem 1.25rem 4rem; }
  .hero-grid {
    grid-template-columns: 1fr;
    gap: 3rem;
  }
  .hero-visual { justify-content: flex-start; }
  .problem-grid,
  .how-steps,
  .tiers-grid {
    grid-template-columns: 1fr;
  }
  .problem, .how, .tiers { padding: 4rem 1.25rem; }
  .closing { padding: 5rem 1.25rem; }
  .nav { padding: 1rem 1.25rem; }
  .footer-inner {
    flex-direction: column;
    gap: 0.75rem;
    text-align: center;
  }
}

@media (max-width: 480px) {
  .flow-node { padding: 0.75rem 1rem; font-size: 0.75rem; }
  .flow-line { width: 24px; }
}