:root {
  --bg: #0b0c10;
  --bg-alt: #111319;
  --surface: #16181f;
  --surface-2: #1c1f29;
  --border: #262a36;
  --border-strong: #333a4a;
  --text: #e7e9ee;
  --muted: #9aa3b2;
  --faint: #6b7280;
  --accent: #6d8bff;
  --accent-2: #9b6dff;
  --accent-soft: rgba(109, 139, 255, 0.12);
  --hl: #ffd56b;
  --radius: 16px;
  --radius-sm: 10px;
  --maxw: 1120px;
  --shadow: 0 20px 50px -20px rgba(0, 0, 0, 0.7);
  --font: "Inter", system-ui, -apple-system, Segoe UI, Roboto, sans-serif;
}

* { box-sizing: border-box; }

html { scroll-behavior: smooth; }

body {
  margin: 0;
  font-family: var(--font);
  background: var(--bg);
  color: var(--text);
  line-height: 1.6;
  -webkit-font-smoothing: antialiased;
}

.container { width: 100%; max-width: var(--maxw); margin: 0 auto; padding: 0 24px; }
.container.narrow { max-width: 820px; }

a { color: inherit; text-decoration: none; }

h1, h2, h3, h4 { line-height: 1.15; letter-spacing: -0.02em; margin: 0 0 0.5em; font-weight: 700; }
h1 { font-size: clamp(2.2rem, 5vw, 3.6rem); font-weight: 800; }
h2 { font-size: clamp(1.7rem, 3.5vw, 2.5rem); }
h3 { font-size: 1.2rem; }
p { margin: 0 0 1rem; color: var(--muted); }

.eyebrow {
  display: inline-block;
  font-size: 0.78rem;
  font-weight: 600;
  letter-spacing: 0.08em;
  text-transform: uppercase;
  color: var(--accent);
  background: var(--accent-soft);
  border: 1px solid rgba(109, 139, 255, 0.25);
  padding: 4px 12px;
  border-radius: 999px;
  margin-bottom: 16px;
}

kbd {
  font-family: var(--font);
  font-size: 0.8em;
  background: var(--surface-2);
  border: 1px solid var(--border-strong);
  border-bottom-width: 2px;
  border-radius: 6px;
  padding: 1px 6px;
  color: var(--text);
}

/* Buttons */
.btn {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  font-family: var(--font);
  font-weight: 600;
  font-size: 0.95rem;
  padding: 11px 18px;
  border-radius: var(--radius-sm);
  border: 1px solid transparent;
  cursor: pointer;
  transition: transform 0.15s ease, background 0.2s ease, border-color 0.2s ease;
  white-space: nowrap;
}
.btn svg { width: 18px; height: 18px; }
.btn:hover { transform: translateY(-1px); }
.btn-lg { padding: 14px 24px; font-size: 1rem; }
.btn-primary {
  background: linear-gradient(135deg, var(--accent), var(--accent-2));
  color: #fff;
  box-shadow: 0 10px 30px -12px rgba(109, 139, 255, 0.7);
}
.btn-primary:hover { filter: brightness(1.07); }
.btn-ghost {
  background: var(--surface);
  color: var(--text);
  border-color: var(--border-strong);
}
.btn-ghost:hover { background: var(--surface-2); }

/* Header */
.site-header {
  position: sticky;
  top: 0;
  z-index: 50;
  backdrop-filter: blur(12px);
  background: rgba(11, 12, 16, 0.72);
  border-bottom: 1px solid var(--border);
}
.nav { display: flex; align-items: center; gap: 24px; height: 68px; }
.brand { display: inline-flex; align-items: center; gap: 9px; font-weight: 800; font-size: 1.15rem; }
.brand-mark {
  display: grid; place-items: center;
  width: 34px; height: 34px;
  border-radius: 9px;
  overflow: hidden;
}
.brand-mark img { width: 100%; height: 100%; display: block; }
.nav-links { display: flex; gap: 26px; margin-left: 12px; }
.nav-links a { color: var(--muted); font-weight: 500; font-size: 0.95rem; }
.nav-links a:hover { color: var(--text); }
.nav-actions { display: flex; align-items: center; gap: 12px; margin-left: auto; }
.nav-toggle {
  display: none;
  background: var(--surface);
  border: 1px solid var(--border-strong);
  color: var(--text);
  border-radius: 9px;
  width: 40px; height: 40px;
  cursor: pointer;
}
.nav-toggle svg { width: 20px; height: 20px; }

/* Hero */
.hero {
  position: relative;
  padding: 88px 0 96px;
  background:
    radial-gradient(900px 500px at 80% -10%, rgba(109, 139, 255, 0.18), transparent 60%),
    radial-gradient(700px 400px at 0% 10%, rgba(155, 109, 255, 0.12), transparent 55%);
  overflow: hidden;
}
.hero-inner {
  display: grid;
  grid-template-columns: 1.05fr 0.95fr;
  gap: 56px;
  align-items: center;
}
.lead { font-size: 1.12rem; max-width: 540px; }
.lead strong { color: var(--text); }
.hero-cta { display: flex; flex-wrap: wrap; gap: 14px; margin-top: 28px; }
.hero-stats { display: flex; gap: 36px; margin-top: 40px; }
.hero-stats div { display: flex; flex-direction: column; }
.hero-stats strong { font-size: 1.7rem; font-weight: 800; color: var(--text); }
.hero-stats span { font-size: 0.82rem; color: var(--faint); }

/* Hero visual / browser mock */
.hero-visual { display: flex; justify-content: center; position: relative; }
.browser {
  width: 100%;
  max-width: 460px;
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: 14px;
  box-shadow: var(--shadow);
  overflow: hidden;
}
.browser-bar {
  display: flex; align-items: center; gap: 7px;
  padding: 12px 14px;
  background: var(--surface-2);
  border-bottom: 1px solid var(--border);
}
.dot { width: 11px; height: 11px; border-radius: 50%; background: #3a3f4d; }
.dot:nth-child(1) { background: #ff5f57; }
.dot:nth-child(2) { background: #febc2e; }
.dot:nth-child(3) { background: #28c840; }
.browser-url {
  margin-left: 10px;
  font-size: 0.8rem;
  color: var(--faint);
  background: var(--bg);
  border: 1px solid var(--border);
  padding: 4px 12px;
  border-radius: 999px;
  overflow: hidden;
  text-overflow: ellipsis;
  white-space: nowrap;
  max-width: 72%;
}
.browser-shot { max-width: 560px; }
.browser-popup { max-width: 400px; }
.shot { display: block; width: 100%; height: auto; }
.float-card {
  position: absolute;
  left: -30px;
  bottom: -26px;
  width: 250px;
  border: 1px solid var(--border-strong);
  border-radius: 12px;
  overflow: hidden;
  box-shadow: var(--shadow);
  transform: rotate(-3deg);
}
.float-card img { display: block; width: 100%; height: auto; }
.chip {
  display: inline-flex; align-items: center; gap: 6px;
  font-size: 0.82rem; font-weight: 600;
  background: var(--surface-2);
  border: 1px solid var(--border-strong);
  color: var(--text);
  padding: 7px 11px;
  border-radius: 8px;
  cursor: pointer;
}
.chip svg { width: 15px; height: 15px; }
.chip-save { background: var(--accent-soft); border-color: rgba(109,139,255,0.4); color: var(--accent); }

/* Sections */
.section { padding: 88px 0; }
.section-alt { background: var(--bg-alt); border-top: 1px solid var(--border); border-bottom: 1px solid var(--border); }
.section-head { text-align: center; max-width: 680px; margin: 0 auto 56px; }
.section-head p { font-size: 1.05rem; }

/* Feature grid */
.grid { display: grid; gap: 22px; }
.grid-3 { grid-template-columns: repeat(3, 1fr); }
.card {
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 26px;
  transition: transform 0.18s ease, border-color 0.2s ease, background 0.2s ease;
}
.card:hover { transform: translateY(-4px); border-color: var(--border-strong); background: var(--surface-2); }
.card-icon {
  display: grid; place-items: center;
  width: 46px; height: 46px;
  border-radius: 12px;
  background: var(--accent-soft);
  color: var(--accent);
  margin-bottom: 16px;
}
.card-icon svg { width: 24px; height: 24px; }
.card h3 { margin-bottom: 8px; }
.card p { margin: 0; font-size: 0.95rem; }

/* Steps */
.steps { display: grid; grid-template-columns: repeat(4, 1fr); gap: 22px; }
.step {
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 28px 22px;
  position: relative;
}
.step-num {
  display: grid; place-items: center;
  width: 38px; height: 38px;
  border-radius: 50%;
  font-weight: 800;
  background: linear-gradient(135deg, var(--accent), var(--accent-2));
  color: #fff;
  margin-bottom: 16px;
}
.step h3 { margin-bottom: 6px; }
.step p { margin: 0; font-size: 0.92rem; }

/* Privacy */
.privacy-grid { display: grid; grid-template-columns: 1.2fr 0.8fr; gap: 48px; align-items: center; }
.privacy-copy h2 { margin-bottom: 14px; }
.checklist { list-style: none; padding: 0; margin: 22px 0 0; }
.checklist li { display: flex; align-items: center; gap: 12px; padding: 8px 0; color: var(--text); }
.checklist svg { width: 20px; height: 20px; color: #4ade80; flex-shrink: 0; }
.privacy-card {
  background: var(--surface);
  border: 1px solid var(--border-strong);
  border-radius: var(--radius);
  padding: 32px;
  text-align: center;
}
.privacy-badge {
  display: grid; place-items: center;
  width: 56px; height: 56px;
  border-radius: 14px;
  margin: 0 auto 16px;
  background: var(--accent-soft);
  color: var(--accent);
}
.privacy-badge svg { width: 28px; height: 28px; }
.privacy-card p { margin-bottom: 18px; }

/* FAQ */
.faq { display: flex; flex-direction: column; gap: 12px; }
.faq-item {
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--radius-sm);
  padding: 4px 20px;
  transition: border-color 0.2s ease;
}
.faq-item[open] { border-color: var(--border-strong); }
.faq-item summary {
  display: flex; align-items: center; justify-content: space-between;
  cursor: pointer;
  font-weight: 600;
  font-size: 1.02rem;
  padding: 16px 0;
  list-style: none;
}
.faq-item summary::-webkit-details-marker { display: none; }
.faq-item summary svg { width: 20px; height: 20px; color: var(--muted); transition: transform 0.2s ease; }
.faq-item[open] summary svg { transform: rotate(180deg); }
.faq-item p { margin: 0 0 18px; font-size: 0.96rem; }

/* CTA */
.cta { padding: 96px 0; text-align: center; background:
  radial-gradient(700px 400px at 50% 0%, rgba(109,139,255,0.18), transparent 60%);
  border-top: 1px solid var(--border);
}
.cta-inner h2 { max-width: 640px; margin: 0 auto 14px; }
.cta-inner p { max-width: 520px; margin: 0 auto 28px; font-size: 1.05rem; }
.cta .hero-cta { justify-content: center; }

/* ===== Product story sections (index.html) ===== */
/* Problem */
.problem-steps {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  justify-content: center;
  gap: 12px;
  margin-bottom: 22px;
}
.problem-steps span {
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: 10px;
  padding: 10px 18px;
  font-weight: 600;
  color: var(--text);
}
.problem-steps svg { width: 18px; height: 18px; color: var(--faint); flex-shrink: 0; }
.problem-punch { text-align: center; font-size: 1.2rem; margin: 0; }
.problem-punch strong { color: var(--text); }

/* Learning loop */
.loop {
  position: relative;
  display: grid;
  grid-template-columns: repeat(5, 1fr);
  gap: 16px;
}
.loop::before {
  content: "";
  position: absolute;
  top: 20px;
  left: 8%;
  right: 8%;
  height: 2px;
  border-radius: 1px;
  background: linear-gradient(90deg, rgba(109, 139, 255, 0.45), rgba(155, 109, 255, 0.45));
}
.loop-step {
  position: relative;
  z-index: 1;
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 22px 18px;
  box-shadow: 0 16px 34px -22px rgba(0, 0, 0, 0.6);
  transition: transform 0.18s ease, border-color 0.2s ease;
}
.loop-step:hover { transform: translateY(-3px); border-color: var(--border-strong); }
.loop-step .step-num { margin-bottom: 12px; }
.loop-step h3 { font-size: 1.05rem; margin-bottom: 6px; }
.loop-step p { margin: 0; font-size: 0.88rem; }

/* Features */
.feature {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 64px;
  align-items: center;
  margin-bottom: 96px;
}
.feature.flip .feature-visual { order: -1; }
.feature-copy h3 { font-size: 1.55rem; margin-bottom: 10px; }
.feature-copy p { font-size: 1rem; }
.feature-chips { display: flex; flex-wrap: wrap; gap: 8px; margin-top: 20px; }
.feature-chips .chip { cursor: default; }
.feature-visual { display: flex; flex-direction: column; align-items: center; }
.visual-note { margin: 12px 0 0; font-size: 0.82rem; color: var(--faint); text-align: center; }

/* Vocabulary Radar mockup */
.radar-panel {
  width: 100%;
  max-width: 460px;
  background: var(--surface);
  border: 1px solid var(--border-strong);
  border-radius: 14px;
  box-shadow: var(--shadow);
  padding: 18px;
}
.radar-head {
  display: flex;
  align-items: center;
  gap: 8px;
  font-size: 0.88rem;
  font-weight: 600;
  color: var(--muted);
  margin-bottom: 14px;
}
.radar-head svg { width: 16px; height: 16px; color: var(--accent); flex-shrink: 0; }
.radar-search {
  display: flex;
  align-items: center;
  gap: 8px;
  background: var(--bg);
  border: 1px solid var(--border);
  border-radius: 10px;
  padding: 9px 12px;
  color: var(--faint);
  font-size: 0.85rem;
  margin-bottom: 14px;
}
.radar-search svg { width: 15px; height: 15px; flex-shrink: 0; }
.radar-list { list-style: none; margin: 0; padding: 0; display: flex; flex-direction: column; gap: 10px; }
.radar-item {
  background: var(--bg-alt);
  border: 1px solid var(--border);
  border-radius: 12px;
  padding: 12px 14px;
}
.radar-top { display: flex; align-items: center; gap: 8px; }
.radar-top strong { font-size: 0.95rem; }
.radar-chip {
  font-size: 0.68rem;
  font-weight: 700;
  text-transform: uppercase;
  letter-spacing: 0.04em;
  padding: 2px 8px;
  border-radius: 999px;
  background: var(--surface-2);
  color: var(--muted);
  border: 1px solid var(--border-strong);
}
.chip-form { color: #7dd3fc; background: rgba(56, 189, 248, 0.1); border-color: rgba(56, 189, 248, 0.3); }
.chip-phrase { color: #c4b5fd; background: rgba(139, 92, 246, 0.1); border-color: rgba(139, 92, 246, 0.3); }
.chip-synonym { color: #86efac; background: rgba(74, 222, 128, 0.1); border-color: rgba(74, 222, 128, 0.3); }
.radar-save {
  margin-left: auto;
  font-size: 0.72rem;
  font-weight: 600;
  color: var(--accent);
  background: var(--accent-soft);
  border: 1px solid rgba(109, 139, 255, 0.4);
  border-radius: 8px;
  padding: 4px 10px;
  white-space: nowrap;
}
.radar-related { margin: 8px 0 2px; font-size: 0.78rem; color: var(--faint); }
.radar-reason { margin: 0; font-size: 0.82rem; color: var(--muted); }

/* Why Vocab */
.compare { display: grid; grid-template-columns: repeat(3, 1fr); gap: 22px; }
.compare-item {
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 26px;
}
.compare-item h4 { margin-bottom: 14px; font-size: 1.02rem; }
.compare-path { display: flex; flex-wrap: wrap; align-items: center; gap: 8px; font-size: 0.85rem; color: var(--muted); }
.compare-path span {
  background: var(--bg-alt);
  border: 1px solid var(--border);
  border-radius: 8px;
  padding: 5px 10px;
  white-space: nowrap;
}
.compare-path svg { width: 13px; height: 13px; color: var(--faint); flex-shrink: 0; }
.compare-end { color: var(--faint); opacity: 0.75; }
.compare-winner {
  border-color: rgba(109, 139, 255, 0.5);
  background: linear-gradient(180deg, rgba(109, 139, 255, 0.1), var(--surface));
  box-shadow: 0 16px 40px -24px rgba(109, 139, 255, 0.5);
}
.compare-winner h4 { color: var(--accent); }
.compare-winner .compare-end { color: var(--accent); opacity: 1; font-weight: 600; }
.compare-note { margin: 16px 0 0; font-size: 0.88rem; }

/* Effortless band */
.band {
  padding: 64px 0;
  background: linear-gradient(135deg, rgba(109, 139, 255, 0.14), rgba(155, 109, 255, 0.14));
  border-top: 1px solid var(--border);
  border-bottom: 1px solid var(--border);
  text-align: center;
}
.band p {
  font-size: clamp(1.15rem, 2.4vw, 1.5rem);
  color: var(--muted);
  max-width: 760px;
  margin: 0 auto;
}
.band strong { color: var(--text); }

/* BYOK */
.byok-card {
  display: flex;
  gap: 22px;
  align-items: flex-start;
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 32px;
}
.byok-card .card-icon { margin-bottom: 0; flex-shrink: 0; }
.byok-card h3 { margin-bottom: 8px; }
.byok-note { margin: 10px 0 0; font-size: 0.85rem; color: var(--faint); }

/* Footer byline */
.footer-byline { font-size: 0.85rem; }
.footer-byline a { color: var(--accent); font-weight: 600; }
.footer-byline a:hover { text-decoration: underline; }

/* Footer */
.site-footer { background: var(--bg-alt); border-top: 1px solid var(--border); padding: 56px 0 28px; }
.footer-grid { display: grid; grid-template-columns: 1.6fr 1fr 1fr 1fr; gap: 32px; }
.footer-brand p { font-size: 0.92rem; max-width: 260px; margin-top: 14px; }
.footer-col h4 { font-size: 0.82rem; text-transform: uppercase; letter-spacing: 0.06em; color: var(--faint); margin-bottom: 14px; }
.footer-col a { display: block; color: var(--muted); font-size: 0.92rem; padding: 5px 0; }
.footer-col a:hover { color: var(--text); }
.footer-bottom {
  display: flex; align-items: center; justify-content: space-between;
  margin-top: 40px; padding-top: 22px;
  border-top: 1px solid var(--border);
  font-size: 0.85rem; color: var(--faint);
}
.footer-bottom a { display: inline-flex; align-items: center; gap: 6px; }
.footer-bottom a svg { width: 16px; height: 16px; }

/* ===== Privacy policy page (privacy.html) ===== */
.policy-hero { padding: 64px 0 8px; }
.policy-hero h1 { margin-bottom: 14px; }
.policy-hero .lead { max-width: 620px; }
.policy-meta { margin: 18px 0 0; font-size: 0.88rem; color: var(--faint); }
.policy-meta strong { color: var(--muted); font-weight: 600; }
.back-link {
  display: inline-flex; align-items: center; gap: 7px;
  color: var(--muted); font-weight: 500; font-size: 0.9rem;
  margin-bottom: 28px;
}
.back-link svg { width: 16px; height: 16px; }
.back-link:hover { color: var(--text); }

.policy { padding: 40px 0 96px; }
.policy article { margin-bottom: 44px; }
.policy h2 {
  display: flex; align-items: center; gap: 12px;
  font-size: 1.25rem;
  margin-bottom: 12px;
}
.policy h2::before {
  content: "";
  width: 4px; height: 18px;
  border-radius: 2px;
  background: linear-gradient(180deg, var(--accent), var(--accent-2));
  flex-shrink: 0;
}
.policy p { font-size: 0.98rem; }
.policy ul { margin: 0 0 1rem; padding-left: 20px; color: var(--muted); }
.policy li { margin-bottom: 8px; font-size: 0.96rem; }
.policy li::marker { color: var(--accent); }
.policy li strong { color: var(--text); }
.policy code {
  font-family: ui-monospace, SFMono-Regular, Menlo, Consolas, monospace;
  font-size: 0.88em;
  background: var(--surface-2);
  border: 1px solid var(--border);
  border-radius: 6px;
  padding: 1px 6px;
  color: var(--text);
}
.policy a { color: var(--accent); font-weight: 500; }
.policy a:hover { text-decoration: underline; }

/* Reveal animation (progressive enhancement: only hides when JS is active) */
.js .reveal { opacity: 0; transform: translateY(18px); transition: opacity 0.6s ease, transform 0.6s ease; }
.js .reveal.in { opacity: 1; transform: none; }

@media (prefers-reduced-motion: reduce) {
  html { scroll-behavior: auto; }
  .reveal { opacity: 1; transform: none; transition: none; }
  .btn:hover, .card:hover { transform: none; }
}

/* Responsive */
@media (max-width: 900px) {
  .hero-inner { grid-template-columns: 1fr; gap: 40px; }
  .grid-3 { grid-template-columns: repeat(2, 1fr); }
  .steps { grid-template-columns: repeat(2, 1fr); }
  .privacy-grid { grid-template-columns: 1fr; gap: 32px; }
  .footer-grid { grid-template-columns: 1fr 1fr; }
  .feature { grid-template-columns: 1fr; gap: 36px; margin-bottom: 72px; }
  .feature.flip .feature-visual { order: 0; }
  .loop { grid-template-columns: repeat(3, 1fr); }
  .loop::before { display: none; }
  .compare { grid-template-columns: 1fr; }
}
@media (max-width: 620px) {
  .nav-links { display: none; }
  .nav-toggle { display: grid; place-items: center; }
  .nav-actions { gap: 8px; }
  .nav-actions .btn-ghost { display: none; }
  .nav-actions .btn-primary { padding: 9px 14px; font-size: 0.85rem; }
  .nav-links.open {
    display: flex; flex-direction: column;
    position: absolute; top: 68px; left: 0; right: 0;
    background: var(--bg); border-bottom: 1px solid var(--border);
    padding: 16px 24px; gap: 14px;
  }
  .grid-3, .steps { grid-template-columns: 1fr; }
  .footer-grid { grid-template-columns: 1fr; }
  .hero-stats { gap: 24px; flex-wrap: wrap; }
  .hero { padding: 56px 0 64px; }
  .section { padding: 64px 0; }
  .loop { grid-template-columns: 1fr; }
  .float-card { display: none; }
  .byok-card { flex-direction: column; }
  .feature-copy h3 { font-size: 1.35rem; }
}
@media (max-width: 360px) {
  .nav-actions .btn-primary { padding: 9px; font-size: 0; }
}