/* Base reset */
*, *::before, *::after { box-sizing: border-box; margin: 0; padding: 0; }
html { -webkit-font-smoothing: antialiased; text-rendering: optimizeLegibility; scroll-behavior: smooth; }
body { min-height: 100vh; font-family: var(--font-body, system-ui, -apple-system, BlinkMacSystemFont, 'Segoe UI', sans-serif); background: var(--color-bg); color: var(--color-text); line-height: 1.7; }
img, svg { display: block; max-width: 100%; height: auto; }
a { color: inherit; text-decoration: none; }
button { font: inherit; color: inherit; background: none; border: none; cursor: pointer; }

:root {
  --font-body: 'Work Sans', system-ui, -apple-system, BlinkMacSystemFont, 'Segoe UI', sans-serif;
  --font-display: 'Instrument Serif', 'Georgia', serif;

  --color-bg: #09090b;
  --color-surface: #111827;
  --color-surface-soft: #020617;
  --color-surface-alt: #020617;
  --color-border-subtle: rgba(148, 163, 184, 0.25);
  --color-border-strong: rgba(148, 163, 184, 0.45);
  --color-text: #f9fafb;
  --color-text-muted: #9ca3af;
  --color-accent: #22c55e;
  --color-accent-soft: rgba(34, 197, 94, 0.12);

  --radius-sm: 0.375rem;
  --radius-md: 0.75rem;
  --radius-full: 9999px;

  --shadow-soft: 0 18px 45px rgba(15, 23, 42, 0.65);

  --space-1: 0.25rem;
  --space-2: 0.5rem;
  --space-3: 0.75rem;
  --space-4: 1rem;
  --space-5: 1.25rem;
  --space-6: 1.5rem;
  --space-8: 2rem;
  --space-10: 2.5rem;
  --space-12: 3rem;
  --space-16: 4rem;

  --text-xs: 0.75rem;
  --text-sm: 0.875rem;
  --text-base: 1rem;
  --text-lg: 1.125rem;
  --text-xl: 1.5rem;
  --text-2xl: 2rem;
}

[data-theme="light"] {
  --color-bg: #f9fafb;
  --color-surface: #ffffff;
  --color-surface-soft: #f3f4f6;
  --color-surface-alt: #f3f4f6;
  --color-border-subtle: rgba(148, 163, 184, 0.3);
  --color-border-strong: rgba(15, 23, 42, 0.3);
  --color-text: #0b1120;
  --color-text-muted: #64748b;
  --shadow-soft: 0 18px 45px rgba(15, 23, 42, 0.12);
}

.container {
  width: 100%;
  max-width: 960px;
  margin-inline: auto;
  padding-inline: var(--space-4);
}

.site-header {
  position: sticky;
  top: 0;
  z-index: 40;
  backdrop-filter: blur(18px);
  background: linear-gradient(to bottom, rgba(15,23,42,0.95), rgba(15,23,42,0.75));
  border-bottom: 1px solid rgba(148,163,184,0.25);
}

[data-theme="light"] .site-header {
  backdrop-filter: blur(18px);
  background: rgba(249,250,251,0.96);
}

.header-inner {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding-block: var(--space-3);
  gap: var(--space-4);
}

.brand {
  display: flex;
  align-items: center;
  gap: var(--space-3);
}

.brand-mark {
  width: 40px;
  height: 40px;
}

.mark-ring {
  fill: none;
  stroke: rgba(148,163,184,0.6);
  stroke-width: 1.5;
}

.mark-arc {
  fill: none;
  stroke: var(--color-accent);
  stroke-width: 1.7;
  stroke-linecap: round;
}

.mark-dot {
  fill: var(--color-accent);
}

.brand-text { display: flex; flex-direction: column; }
.brand-title { font-family: var(--font-display); font-size: var(--text-lg); letter-spacing: 0.02em; }
.brand-tagline { font-size: var(--text-xs); color: var(--color-text-muted); text-transform: uppercase; letter-spacing: 0.18em; }

.nav-main { position: relative; }
.nav-links {
  list-style: none;
  display: flex;
  gap: var(--space-3);
  font-size: var(--text-sm);
}

.nav-links a { padding: 0.35rem 0.6rem; border-radius: 999px; color: var(--color-text-muted); transition: background 180ms ease, color 180ms ease; }
.nav-links a:hover { background: rgba(148,163,184,0.12); color: var(--color-text); }

.nav-toggle { display: none; width: 32px; height: 32px; border-radius: 999px; border: 1px solid var(--color-border-subtle); align-items: center; justify-content: center; gap: 4px; padding: 0 7px; }
.nav-toggle span { display: block; width: 100%; height: 2px; background: var(--color-text); border-radius: 999px; transition: transform 180ms ease, opacity 180ms ease; }

.theme-toggle {
  width: 32px;
  height: 32px;
  border-radius: 999px;
  border: 1px solid var(--color-border-subtle);
  display: flex;
  align-items: center;
  justify-content: center;
  color: var(--color-text-muted);
  transition: border 180ms ease, background 180ms ease, color 180ms ease, transform 180ms ease;
}
.theme-toggle:hover { border-color: var(--color-border-strong); background: rgba(15,23,42,0.6); transform: translateY(-1px); }
[data-theme="light"] .theme-toggle:hover { background: rgba(148,163,184,0.12); }

.hero {
  padding-block: var(--space-12);
  background: radial-gradient(circle at top left, rgba(34,197,94,0.14), transparent 55%),
              radial-gradient(circle at bottom right, rgba(56,189,248,0.16), transparent 55%),
              var(--color-bg);
}

.hero-inner { max-width: 780px; }

.eyebrow {
  font-size: var(--text-xs);
  text-transform: uppercase;
  letter-spacing: 0.21em;
  color: var(--color-text-muted);
  margin-bottom: var(--space-3);
}

.hero h1 {
  font-family: var(--font-display);
  font-size: clamp(2.25rem, 4vw, 3.2rem);
  line-height: 1.1;
  margin-bottom: var(--space-4);
}

.hero-question { color: var(--color-accent); text-shadow: 0 0 22px rgba(34,197,94,0.35); }

.hero-text { font-size: var(--text-lg); color: var(--color-text-muted); margin-bottom: var(--space-5); }

.hero-actions { display: flex; flex-wrap: wrap; gap: var(--space-3); margin-bottom: var(--space-3); }

.hero-meta { font-size: var(--text-sm); color: var(--color-text-muted); max-width: 40rem; }

.section {
  padding-block: var(--space-10);
  background: var(--color-bg);
}

.section.alt {
  background: radial-gradient(circle at top right, rgba(15,118,110,0.26), transparent 55%),
              var(--color-surface-soft);
}

.section-inner { max-width: 820px; }
.section-inner.narrow { max-width: 680px; }

.section h2 {
  font-family: var(--font-display);
  font-size: var(--text-2xl);
  margin-bottom: var(--space-3);
}

.section p { font-size: var(--text-base); color: var(--color-text-muted); margin-bottom: var(--space-3); }

.grid.two {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: var(--space-4);
  margin-top: var(--space-4);
}

.card {
  background: linear-gradient(135deg, rgba(15,23,42,0.9), rgba(15,23,42,0.65));
  border-radius: var(--radius-md);
  padding: var(--space-4);
  border: 1px solid var(--color-border-subtle);
  box-shadow: 0 1px 0 rgba(15,23,42,0.5);
  position: relative;
  overflow: hidden;
}

[data-theme="light"] .card {
  background: linear-gradient(135deg, #ffffff, #f9fafb);
}

.card::before {
  content: "";
  position: absolute;
  inset: -40%;
  background: radial-gradient(circle at top, rgba(34,197,94,0.11), transparent 65%);
  opacity: 0;
  transition: opacity 260ms ease-out;
  pointer-events: none;
}

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

.card h3 {
  font-size: var(--text-lg);
  margin-bottom: var(--space-2);
}

.card p { font-size: var(--text-sm); }

.card.focus {
  border-color: rgba(34,197,94,0.7);
  box-shadow: var(--shadow-soft);
}

.bullet-list {
  list-style: disc;
  padding-left: 1.2rem;
  margin-bottom: var(--space-3);
}

.bullet-list li { margin-bottom: 0.4rem; color: var(--color-text-muted); }

.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 0.35rem;
  padding-inline: var(--space-4);
  padding-block: 0.6rem;
  border-radius: var(--radius-full);
  font-size: var(--text-sm);
  border: 1px solid transparent;
  transition: background 200ms ease, color 200ms ease, border-color 200ms ease, transform 150ms ease, box-shadow 150ms ease;
}

.btn-primary {
  background: linear-gradient(135deg, #22c55e, #2dd4bf);
  color: #022c22;
  box-shadow: 0 16px 40px rgba(16,185,129,0.35);
}

.btn-primary:hover {
  transform: translateY(-1px);
  box-shadow: 0 18px 45px rgba(16,185,129,0.5);
}

.btn-ghost {
  border-color: var(--color-border-subtle);
  color: var(--color-text-muted);
}

.btn-ghost:hover {
  border-color: var(--color-border-strong);
  background: rgba(148,163,184,0.15);
}

.signup { margin-top: var(--space-4); border-radius: var(--radius-md); padding: var(--space-4); background: var(--color-surface); border: 1px solid var(--color-border-subtle); }
.signup-label { display: block; font-size: var(--text-sm); margin-bottom: var(--space-3); color: var(--color-text); }
.signup-row { display: flex; flex-wrap: wrap; gap: var(--space-3); align-items: center; }
.signup input[type="email"] {
  flex: 1 1 220px;
  padding: 0.6rem 0.8rem;
  border-radius: var(--radius-full);
  border: 1px solid var(--color-border-subtle);
  background: var(--color-surface-soft);
  color: var(--color-text);
  font-size: var(--text-sm);
}

.signup input[type="email"]::placeholder { color: var(--color-text-muted); }

.signup input[type="email"]:focus-visible {
  outline: 2px solid var(--color-accent);
  outline-offset: 1px;
}

.signup-hint { font-size: var(--text-xs); color: var(--color-text-muted); margin-top: var(--space-3); }

.site-footer {
  border-top: 1px solid rgba(148,163,184,0.3);
  background: var(--color-surface-soft);
}

.footer-inner {
  padding-block: var(--space-4);
  display: flex;
  flex-wrap: wrap;
  gap: var(--space-2);
  justify-content: space-between;
  font-size: var(--text-xs);
  color: var(--color-text-muted);
}

.reveal {
  opacity: 0;
  transform: translateY(22px);
  transition: opacity 600ms ease, transform 600ms ease;
}

.reveal.visible {
  opacity: 1;
  transform: translateY(0);
}

@media (prefers-reduced-motion: reduce) {
  html { scroll-behavior: auto; }
  .reveal { opacity: 1 !important; transform: none !important; }
  .card::before { display: none; }
}

@media (max-width: 768px) {
  .header-inner { align-items: center; }
  .nav-links {
    position: absolute;
    right: 0;
    top: calc(100% + 0.5rem);
    padding: var(--space-3);
    border-radius: var(--radius-md);
    background: var(--color-surface);
    border: 1px solid var(--color-border-subtle);
    box-shadow: var(--shadow-soft);
    flex-direction: column;
    align-items: flex-start;
    min-width: 230px;
    opacity: 0;
    pointer-events: none;
    transform: translateY(-6px);
    transition: opacity 160ms ease, transform 160ms ease;
  }

  .nav-main.open .nav-links {
    opacity: 1;
    pointer-events: auto;
    transform: translateY(0);
  }

  .nav-toggle { display: inline-flex; }

  .nav-main.open .nav-toggle span:nth-child(1) { transform: translateY(2px) rotate(35deg); }
  .nav-main.open .nav-toggle span:nth-child(2) { transform: translateY(-2px) rotate(-35deg); }

  .nav-main:not(.open) .nav-toggle span:nth-child(1) { transform: translateY(-3px); }
  .nav-main:not(.open) .nav-toggle span:nth-child(2) { transform: translateY(3px); }

  .hero { padding-block: var(--space-10); }
  .grid.two { grid-template-columns: minmax(0,1fr); }
}

@media (max-width: 480px) {
  .hero h1 { font-size: clamp(1.9rem, 8vw, 2.4rem); }
  .hero-text { font-size: var(--text-base); }
}