@font-face {
  font-family: 'Manrope';
  src: url('assets/fonts/Manrope.ttf') format('truetype-variations');
  font-weight: 200 800;
  font-display: swap;
}

:root {
  color-scheme: dark;
  --bg: #09090b;  --fg: #fafafa;
  --panel: #15151a;  --panel-border: rgba(255,255,255,.09);
  --border: #27272a;  --muted: #1c1c1f;  --muted-fg: #a1a1aa;

  --accent: #fbc711;  --accent-hover: #ffd646;  --on-accent: #201800;
  --accent-container: #4b3c05;  --on-accent-container: #fde694;

  --link: #2295f1;
  --radius: 0.875rem;
  --font-mono: ui-monospace, 'SFMono-Regular', Consolas, monospace;
}

:root[data-theme="light"] {
  color-scheme: light;
  --bg: #ffffff;  --fg: #09090b;
  --panel: #ffffff;  --panel-border: rgba(24, 24, 40, 0.10);
  --border: #e4e4e7;  --muted: #f4f4f5;  --muted-fg: #52525b;
  --accent-container: #fff8e2;  --on-accent-container: #5f4c06;
  --link: #1b74bc;
}

* { box-sizing: border-box; }
html { scroll-behavior: smooth; }
@media (prefers-reduced-motion: reduce) {
  html { scroll-behavior: auto; }
  * { animation-duration: 0.01ms !important; animation-iteration-count: 1 !important; transition-duration: 0.01ms !important; }
}

body {
  margin: 0;
  background: var(--bg);
  color: var(--fg);
  font-family: 'Manrope', system-ui, sans-serif;
  line-height: 1.6;
}

a { color: var(--link); }

.sr-only {
  position: absolute; width: 1px; height: 1px; padding: 0; margin: -1px;
  overflow: hidden; clip: rect(0,0,0,0); white-space: nowrap; border: 0;
}

/* ---------- top nav ---------- */

.topnav {
  position: sticky;
  top: 0;
  z-index: 50;
  background: var(--bg);
  border-bottom: 1px solid var(--border);
  transition: box-shadow 0.2s ease;
}
.topnav.is-scrolled { box-shadow: 0 4px 16px rgba(0,0,0,0.18); }

.topnav-inner {
  max-width: 1160px;
  margin: 0 auto;
  padding: 14px 24px;
  display: flex;
  align-items: center;
  gap: 24px;
  flex-wrap: wrap;
  row-gap: 10px;
}

.brand {
  display: flex;
  align-items: center;
  gap: 8px;
  font-weight: 700;
  font-size: 1.05rem;
  letter-spacing: -0.01em;
  color: var(--fg);
  text-decoration: none;
  color: var(--accent);
}

.topnav-links {
  display: flex;
  gap: 20px;
  flex-wrap: wrap;
  margin-left: 8px;
  flex: 1;
}
.topnav-links a {
  color: var(--muted-fg);
  text-decoration: none;
  font-weight: 600;
  font-size: 0.9rem;
}
.topnav-links a:hover { color: var(--fg); }

.theme-toggle {
  width: 36px; height: 36px;
  display: inline-flex; align-items: center; justify-content: center;
  border-radius: 999px;
  border: 1px solid var(--border);
  background: transparent;
  color: var(--fg);
  cursor: pointer;
}
.theme-toggle:hover { background: var(--muted); }
.theme-toggle:focus-visible { outline: 2px solid var(--accent); outline-offset: 2px; }
.theme-toggle svg[hidden] { display: none; }

/* ---------- shared ---------- */

main { display: block; }

.band {
  max-width: 1160px;
  margin: 0 auto;
  padding: 88px 24px;
}
.band-alt { background: var(--muted); max-width: none; }
.band-alt > * { max-width: 1160px; margin-left: auto; margin-right: auto; }

.band h2 {
  font-size: clamp(1.75rem, 3vw, 2.25rem);
  font-weight: 700;
  letter-spacing: -0.02em;
  margin: 0 0 8px;
}
.section-lede { color: var(--muted-fg); font-size: 1.05rem; margin: 0 0 40px; max-width: 60ch; }

code {
  font-family: var(--font-mono);
  background: var(--muted);
  padding: 0.15em 0.4em;
  border-radius: 5px;
  font-size: 0.9em;
}

.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  font: inherit;
  font-weight: 700;
  padding: 13px 24px;
  border-radius: var(--radius);
  border: 1px solid transparent;
  text-decoration: none;
  cursor: pointer;
}
.btn:focus-visible { outline: 2px solid var(--accent); outline-offset: 2px; }
.btn-primary { background: var(--accent); color: var(--on-accent); }
.btn-primary:hover { background: var(--accent-hover); }
.btn-ghost { background: transparent; color: var(--fg); border-color: var(--border); }
.btn-ghost:hover { background: var(--muted); }

/* ---------- hero ---------- */

.hero {
  max-width: 1160px;
  margin: 0 auto;
  padding: 88px 24px 64px;
  display: grid;
  grid-template-columns: 1.1fr 0.9fr;
  gap: 48px;
  align-items: center;
}

.eyebrow {
  font-family: var(--font-mono);
  font-size: 0.8125rem;
  font-weight: 600;
  letter-spacing: 0.04em;
  color: var(--accent);
  margin: 0 0 16px;
  text-transform: uppercase;
}

.hero h1 {
  font-size: clamp(2.25rem, 4.5vw, 3.5rem);
  line-height: 1.08;
  letter-spacing: -0.03em;
  font-weight: 800;
  margin: 0 0 20px;
}

.lede { font-size: 1.125rem; color: var(--muted-fg); max-width: 56ch; margin: 0 0 32px; }

.hero-actions { display: flex; gap: 12px; flex-wrap: wrap; margin-bottom: 16px; }
.hero-meta { color: var(--muted-fg); font-size: 0.875rem; margin: 0; }

.hero-diagram { aspect-ratio: 1; max-width: 420px; margin: 0 auto; }
.hero-diagram .ring { fill: none; stroke: var(--border); stroke-width: 1.5; }
.hero-diagram .ring-mid { stroke-dasharray: 4 8; }
.hero-diagram .blocked { stroke: var(--muted-fg); stroke-width: 3; stroke-linecap: round; opacity: 0.5; }
.hero-diagram .tunnel { stroke: var(--accent); stroke-width: 4; stroke-linecap: round; }
.hero-diagram .core { fill: var(--accent-container); stroke: var(--accent); stroke-width: 2; }
.hero-diagram .core-check { stroke: var(--accent); }

/* ---------- how it works ---------- */

.steps {
  list-style: none;
  margin: 0;
  padding: 0;
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 32px;
}
.steps li { border-top: 2px solid var(--border); padding-top: 20px; }
.step-no {
  display: block;
  font-family: var(--font-mono);
  font-size: 0.875rem;
  font-weight: 700;
  color: var(--accent);
  margin-bottom: 12px;
}
.steps h3 { font-size: 1.1rem; margin: 0 0 8px; letter-spacing: -0.01em; }
.steps p { margin: 0; color: var(--muted-fg); font-size: 0.95rem; }

/* ---------- feature rows ---------- */

.feature-rows { display: flex; flex-direction: column; }
.feature-row {
  display: grid;
  grid-template-columns: 96px 1fr;
  gap: 24px;
  align-items: baseline;
  padding: 28px 0;
  border-top: 1px solid var(--border);
}
.feature-row:last-child { border-bottom: 1px solid var(--border); }
.feature-num { font-family: var(--font-mono); font-size: 1.75rem; font-weight: 700; color: var(--border); }
.feature-row h3 { margin: 0 0 6px; font-size: 1.15rem; letter-spacing: -0.01em; }
.feature-row p { margin: 0; color: var(--muted-fg); max-width: 60ch; }

/* ---------- download ---------- */

.download-card {
  background: var(--panel);
  border: 1px solid var(--panel-border);
  border-radius: 1.25rem;
  padding: 32px;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 24px;
  flex-wrap: wrap;
}
.download-version { font-weight: 700; font-size: 1.05rem; margin: 0 0 6px; }
.download-req { color: var(--muted-fg); font-size: 0.875rem; margin: 0; max-width: 48ch; }

/* ---------- footer ---------- */

.footer {
  border-top: 1px solid var(--border);
  padding: 32px 24px;
  text-align: center;
  color: var(--muted-fg);
  font-size: 0.875rem;
}

/* ---------- reveal-on-scroll ---------- */

[data-reveal] {
  opacity: 0;
  transform: translateY(16px);
  transition: opacity 0.5s ease, transform 0.5s ease;
}
[data-reveal].is-visible { opacity: 1; transform: none; }
@media (prefers-reduced-motion: reduce) {
  [data-reveal] { opacity: 1; transform: none; }
}

/* ---------- responsive ---------- */

@media (max-width: 900px) {
  .hero { grid-template-columns: 1fr; padding-top: 48px; }
  .hero-diagram { max-width: 280px; order: -1; }
  .steps { grid-template-columns: 1fr; }
}

@media (max-width: 640px) {
  .topnav-links { order: 3; width: 100%; gap: 16px; font-size: 0.85rem; }
}

@media (max-width: 560px) {
  .feature-row { grid-template-columns: 1fr; gap: 8px; }
  .band { padding: 56px 20px; }
}