:root {
  --bg: #0a0f1a;
  --bg-surface: #111827;
  --bg-card: #1a2236;
  --bg-card-hover: #1f2a42;
  --fg: #e8ecf4;
  --fg-muted: #8b95aa;
  --fg-dim: #5a6478;
  --accent: #3b82f6;
  --accent-glow: rgba(59, 130, 246, 0.15);
  --green: #22c55e;
  --green-dim: rgba(34, 197, 94, 0.12);
  --coral: #f97316;
  --coral-dim: rgba(249, 115, 22, 0.12);
  --border: rgba(255, 255, 255, 0.06);
  --radius: 12px;
  --radius-sm: 8px;
  --font-display: 'Space Grotesk', sans-serif;
  --font-body: 'DM Sans', sans-serif;
}

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

body {
  background: var(--bg);
  color: var(--fg);
  font-family: var(--font-body);
  line-height: 1.6;
  -webkit-font-smoothing: antialiased;
}

/* ── Nav ── */
.nav {
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  z-index: 100;
  background: rgba(10, 15, 26, 0.85);
  backdrop-filter: blur(20px);
  border-bottom: 1px solid var(--border);
}

.nav-inner {
  max-width: 1100px;
  margin: 0 auto;
  padding: 16px 24px;
  display: flex;
  align-items: center;
  justify-content: space-between;
}

.nav-logo {
  display: flex;
  align-items: center;
  gap: 10px;
}

.logo-icon {
  width: 32px;
  height: 32px;
  display: flex;
  align-items: center;
  justify-content: center;
}

.logo-text {
  font-family: var(--font-display);
  font-weight: 700;
  font-size: 1.15rem;
  color: var(--fg);
  letter-spacing: -0.02em;
}

.nav-tag {
  font-size: 0.75rem;
  color: var(--fg-muted);
  background: var(--bg-card);
  padding: 4px 12px;
  border-radius: 20px;
  border: 1px solid var(--border);
}

/* ── Hero ── */
.hero {
  padding: 140px 24px 80px;
  text-align: center;
}

.hero-inner {
  max-width: 800px;
  margin: 0 auto;
}

.hero-badge {
  display: inline-block;
  font-size: 0.8rem;
  font-weight: 500;
  color: var(--accent);
  background: var(--accent-glow);
  padding: 6px 16px;
  border-radius: 20px;
  border: 1px solid rgba(59, 130, 246, 0.2);
  margin-bottom: 32px;
  letter-spacing: 0.02em;
}

.hero-title {
  font-family: var(--font-display);
  font-size: clamp(2.8rem, 7vw, 4.5rem);
  font-weight: 700;
  line-height: 1.08;
  letter-spacing: -0.03em;
  color: var(--fg);
  margin-bottom: 24px;
}

.hero-accent {
  background: linear-gradient(135deg, var(--accent), var(--green));
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
}

.hero-lede {
  font-size: 1.15rem;
  color: var(--fg-muted);
  max-width: 560px;
  margin: 0 auto 56px;
  line-height: 1.7;
}

/* ── Calculator Preview ── */
.hero-visual {
  display: flex;
  justify-content: center;
}

.calc-preview {
  background: var(--bg-surface);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  width: 100%;
  max-width: 420px;
  overflow: hidden;
  box-shadow: 0 24px 80px rgba(0, 0, 0, 0.4), 0 0 0 1px var(--border);
}

.calc-header {
  display: flex;
  gap: 6px;
  padding: 14px 18px;
  background: var(--bg-card);
  border-bottom: 1px solid var(--border);
}

.calc-dot {
  width: 10px;
  height: 10px;
  border-radius: 50%;
  background: var(--fg-dim);
}

.calc-body {
  padding: 24px;
}

.calc-row {
  display: flex;
  justify-content: space-between;
  align-items: center;
  padding: 10px 0;
}

.calc-label {
  font-size: 0.9rem;
  color: var(--fg-muted);
}

.calc-value {
  font-family: var(--font-display);
  font-weight: 600;
  font-size: 0.95rem;
  color: var(--fg);
}

.calc-value.accent {
  color: var(--accent);
  font-size: 1.3rem;
}

.calc-divider {
  height: 1px;
  background: var(--border);
  margin: 8px 0;
}

.calc-total {
  padding: 14px 0;
}

.calc-breakdown {
  margin-top: 18px;
}

.calc-bar {
  display: flex;
  height: 8px;
  border-radius: 4px;
  overflow: hidden;
  gap: 2px;
}

.bar-segment {
  border-radius: 4px;
}

.bar-pi { background: var(--accent); }
.bar-tax { background: var(--green); }
.bar-ins { background: var(--coral); }
.bar-other { background: var(--fg-dim); }

.calc-legend {
  display: flex;
  flex-wrap: wrap;
  gap: 12px;
  margin-top: 12px;
}

.legend-item {
  display: flex;
  align-items: center;
  gap: 6px;
  font-size: 0.78rem;
  color: var(--fg-muted);
}

.legend-dot {
  width: 8px;
  height: 8px;
  border-radius: 50%;
}

.dot-pi { background: var(--accent); }
.dot-tax { background: var(--green); }
.dot-ins { background: var(--coral); }
.dot-other { background: var(--fg-dim); }

/* ── Problem Section ── */
.problem {
  padding: 100px 24px;
  background: var(--bg-surface);
  border-top: 1px solid var(--border);
  border-bottom: 1px solid var(--border);
}

.problem-inner {
  max-width: 1100px;
  margin: 0 auto;
}

.section-label {
  font-family: var(--font-display);
  font-size: 0.85rem;
  font-weight: 600;
  text-transform: uppercase;
  letter-spacing: 0.1em;
  color: var(--accent);
  margin-bottom: 48px;
}

.problem-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 24px;
}

.problem-card {
  background: var(--bg-card);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 32px;
  transition: background 0.2s;
}

.problem-card:hover {
  background: var(--bg-card-hover);
}

.problem-icon {
  font-family: var(--font-display);
  font-size: 1.5rem;
  font-weight: 700;
  color: var(--coral);
  background: var(--coral-dim);
  width: 44px;
  height: 44px;
  display: flex;
  align-items: center;
  justify-content: center;
  border-radius: var(--radius-sm);
  margin-bottom: 20px;
}

.problem-card h3 {
  font-family: var(--font-display);
  font-size: 1.15rem;
  font-weight: 600;
  color: var(--fg);
  margin-bottom: 10px;
  letter-spacing: -0.01em;
}

.problem-card p {
  font-size: 0.9rem;
  color: var(--fg-muted);
  line-height: 1.65;
}

/* ── Features ── */
.features {
  padding: 100px 24px;
}

.features-inner {
  max-width: 800px;
  margin: 0 auto;
}

.features-list {
  display: flex;
  flex-direction: column;
  gap: 0;
}

.feature-block {
  display: flex;
  gap: 32px;
  padding: 40px 0;
  border-bottom: 1px solid var(--border);
  align-items: flex-start;
}

.feature-block:last-child {
  border-bottom: none;
}

.feature-number {
  font-family: var(--font-display);
  font-size: 0.85rem;
  font-weight: 600;
  color: var(--fg-dim);
  min-width: 40px;
  padding-top: 2px;
}

.feature-content h3 {
  font-family: var(--font-display);
  font-size: 1.25rem;
  font-weight: 600;
  color: var(--fg);
  margin-bottom: 10px;
  letter-spacing: -0.01em;
}

.feature-content p {
  font-size: 0.95rem;
  color: var(--fg-muted);
  line-height: 1.65;
}

/* ── How Section ── */
.how {
  padding: 100px 24px;
  background: var(--bg-surface);
  border-top: 1px solid var(--border);
  border-bottom: 1px solid var(--border);
}

.how-inner {
  max-width: 1100px;
  margin: 0 auto;
}

.how-grid {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 20px;
}

.how-card {
  background: var(--bg-card);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 28px;
  transition: background 0.2s;
}

.how-card:hover {
  background: var(--bg-card-hover);
}

.how-emoji {
  font-size: 1.5rem;
  margin-bottom: 16px;
  width: 40px;
  height: 40px;
  display: flex;
  align-items: center;
  justify-content: center;
  background: var(--green-dim);
  border-radius: var(--radius-sm);
  color: var(--green);
}

.how-card h3 {
  font-family: var(--font-display);
  font-size: 1rem;
  font-weight: 600;
  color: var(--fg);
  margin-bottom: 8px;
}

.how-card p {
  font-size: 0.85rem;
  color: var(--fg-muted);
  line-height: 1.6;
}

/* ── Closing ── */
.closing {
  padding: 120px 24px;
  text-align: center;
  background: radial-gradient(ellipse at 50% 0%, rgba(59, 130, 246, 0.08) 0%, transparent 70%);
}

.closing-inner {
  max-width: 700px;
  margin: 0 auto;
}

.closing-title {
  font-family: var(--font-display);
  font-size: clamp(1.8rem, 4vw, 2.5rem);
  font-weight: 700;
  line-height: 1.2;
  letter-spacing: -0.02em;
  color: var(--fg);
  margin-bottom: 20px;
}

.closing-text {
  font-size: 1.05rem;
  color: var(--fg-muted);
  line-height: 1.7;
  max-width: 520px;
  margin: 0 auto;
}

/* ── Footer ── */
.footer {
  padding: 48px 24px;
  text-align: center;
  border-top: 1px solid var(--border);
}

.footer-inner {
  max-width: 1100px;
  margin: 0 auto;
}

.footer-logo {
  font-family: var(--font-display);
  font-weight: 700;
  font-size: 1.1rem;
  color: var(--fg);
  margin-bottom: 4px;
}

.footer-tagline {
  font-size: 0.85rem;
  color: var(--fg-dim);
  margin-bottom: 16px;
}

.footer-copy {
  font-size: 0.75rem;
  color: var(--fg-dim);
}

/* ── Responsive ── */
@media (max-width: 768px) {
  .problem-grid {
    grid-template-columns: 1fr;
  }

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

  .feature-block {
    flex-direction: column;
    gap: 12px;
  }

  .hero {
    padding: 120px 20px 60px;
  }

  .hero-title {
    font-size: 2.5rem;
  }

  .calc-preview {
    max-width: 100%;
  }

  .problem, .features, .how, .closing {
    padding: 72px 20px;
  }
}

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

  .nav-tag {
    display: none;
  }

  .hero-title {
    font-size: 2rem;
  }

  .calc-legend {
    flex-direction: column;
    gap: 6px;
  }
}