/* =========================================================
   SecureVault — marketing site
   Aesthetic: deep on-device "vault" dark theme, electric-blue
   accent, editorial-tech typography, non-linear orchestrated motion.
   ========================================================= */

/* ---------- Tokens ---------- */
:root {
  --bg: #07080d;
  --bg-2: #0a0c14;
  --bg-elev: #0d1018;
  --surface: rgba(255, 255, 255, 0.035);
  --surface-2: rgba(255, 255, 255, 0.06);
  --border: rgba(255, 255, 255, 0.09);
  --border-bright: rgba(120, 150, 255, 0.28);

  --text: #eef0f6;
  --text-soft: #c3c8d6;
  --text-dim: #838aa0;
  --text-faint: #565d73;

  --brand: #3b6ff6;
  --brand-bright: #5f92ff;
  --brand-soft: #8fb0ff;
  --violet: #6e5bf0;
  --cyan: #43c7e6;

  --grad-brand: linear-gradient(135deg, #6f9dff 0%, #3b6ff6 46%, #6e5bf0 100%);
  --grad-text: linear-gradient(100deg, #ffffff 0%, #bcd0ff 55%, #8fa9ff 100%);

  --glow: 0 0 80px rgba(59, 111, 246, 0.35);
  --shadow-card: 0 24px 60px -24px rgba(0, 0, 0, 0.8);

  --ease-expo: cubic-bezier(0.16, 1, 0.3, 1);
  --ease-spring: cubic-bezier(0.34, 1.56, 0.64, 1);
  --ease-inout: cubic-bezier(0.65, 0.05, 0.36, 1);

  --maxw: 1180px;
  --radius: 20px;
  --nav-h: 68px;
}

/* ---------- Reset ---------- */
*,
*::before,
*::after { box-sizing: border-box; margin: 0; padding: 0; }

html { scroll-behavior: smooth; -webkit-text-size-adjust: 100%; }

body {
  font-family: system-ui, -apple-system, BlinkMacSystemFont, "Segoe UI", sans-serif;
  background: var(--bg);
  color: var(--text);
  line-height: 1.6;
  font-size: 17px;
  overflow-x: hidden;
  -webkit-font-smoothing: antialiased;
  text-rendering: optimizeLegibility;
}

a { color: inherit; text-decoration: none; }
img { display: block; max-width: 100%; }
button { font-family: inherit; cursor: pointer; }
::selection { background: rgba(95, 146, 255, 0.35); color: #fff; }

/* ---------- Background atmosphere ---------- */
.bg-layer {
  position: fixed;
  inset: 0;
  z-index: -2;
  pointer-events: none;
}
.bg-aurora {
  position: absolute;
  inset: -20%;
  background:
    radial-gradient(42% 42% at 18% 12%, rgba(59, 111, 246, 0.28), transparent 60%),
    radial-gradient(38% 38% at 82% 8%, rgba(110, 91, 240, 0.22), transparent 62%),
    radial-gradient(50% 50% at 70% 80%, rgba(41, 58, 192, 0.2), transparent 65%);
  filter: blur(20px);
  animation: drift 26s var(--ease-inout) infinite alternate;
}
@keyframes drift {
  0%   { transform: translate3d(0,0,0) scale(1); }
  50%  { transform: translate3d(3%, -2%, 0) scale(1.08); }
  100% { transform: translate3d(-3%, 2%, 0) scale(1.04); }
}
.bg-grid {
  position: fixed;
  inset: 0;
  z-index: -2;
  background-image:
    linear-gradient(rgba(255, 255, 255, 0.03) 1px, transparent 1px),
    linear-gradient(90deg, rgba(255, 255, 255, 0.03) 1px, transparent 1px);
  background-size: 64px 64px;
  mask-image: radial-gradient(ellipse 80% 60% at 50% 0%, #000 20%, transparent 75%);
  pointer-events: none;
}
.bg-grain {
  position: fixed;
  inset: 0;
  z-index: -1;
  opacity: 0.05;
  pointer-events: none;
  background-image: url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' width='140' height='140'%3E%3Cfilter id='n'%3E%3CfeTurbulence type='fractalNoise' baseFrequency='0.85' numOctaves='3'/%3E%3C/filter%3E%3Crect width='100%25' height='100%25' filter='url(%23n)'/%3E%3C/svg%3E");
}

/* ---------- Layout ---------- */
.wrap { width: 100%; max-width: var(--maxw); margin: 0 auto; padding: 0 26px; }
section { position: relative; }

.eyebrow {
  font-family: ui-monospace, SFMono-Regular, Menlo, Monaco, Consolas, monospace;
  font-size: 12.5px;
  letter-spacing: 0.22em;
  text-transform: uppercase;
  color: var(--brand-soft);
  display: inline-flex;
  align-items: center;
  gap: 9px;
}
.eyebrow::before {
  content: "";
  width: 7px; height: 7px;
  border-radius: 50%;
  background: var(--brand-bright);
  box-shadow: 0 0 12px 2px var(--brand-bright);
}

h1, h2, h3 { font-family: system-ui, -apple-system, BlinkMacSystemFont, "Segoe UI", sans-serif; font-weight: 700; line-height: 1.04; letter-spacing: -0.02em; }

.gradient-text {
  background: var(--grad-text);
  -webkit-background-clip: text;
  background-clip: text;
  color: transparent;
}

/* ---------- Navbar ---------- */
.nav {
  position: fixed;
  top: 0; left: 0; right: 0;
  height: var(--nav-h);
  z-index: 100;
  display: flex;
  align-items: center;
  transition: background 0.4s var(--ease-expo), border-color 0.4s var(--ease-expo);
  border-bottom: 1px solid transparent;
}
.nav.scrolled {
  background: rgba(7, 8, 13, 0.72);
  backdrop-filter: blur(18px) saturate(140%);
  border-bottom-color: var(--border);
}
.nav .wrap { display: flex; align-items: center; justify-content: space-between; }
.brand { display: flex; align-items: center; gap: 11px; font-family: system-ui, -apple-system, BlinkMacSystemFont, "Segoe UI", sans-serif; font-weight: 700; font-size: 19px; letter-spacing: -0.01em; }
.brand img { width: 32px; height: 32px; border-radius: 9px; box-shadow: 0 4px 16px rgba(59, 111, 246, 0.4); }
.nav-links { display: flex; align-items: center; gap: 34px; }
.nav-links a { color: var(--text-dim); font-size: 15px; font-weight: 500; transition: color 0.25s var(--ease-expo); }
.nav-links a:hover { color: var(--text); }
.nav-cta { display: flex; align-items: center; gap: 14px; }
.nav-toggle { display: none; background: none; border: 0; color: var(--text); }

/* ---------- Buttons ---------- */
.btn {
  position: relative;
  display: inline-flex;
  align-items: center;
  gap: 9px;
  padding: 13px 24px;
  border-radius: 13px;
  font-weight: 600;
  font-size: 15px;
  border: 1px solid transparent;
  transition: transform 0.3s var(--ease-spring), box-shadow 0.4s var(--ease-expo), background 0.3s var(--ease-expo);
  will-change: transform;
}
.btn-primary {
  background: var(--grad-brand);
  color: #fff;
  box-shadow: 0 10px 30px -8px rgba(59, 111, 246, 0.6), inset 0 1px 0 rgba(255, 255, 255, 0.25);
}
.btn-primary:hover { box-shadow: 0 16px 44px -8px rgba(59, 111, 246, 0.8), inset 0 1px 0 rgba(255, 255, 255, 0.3); }
.btn-ghost {
  background: var(--surface);
  border-color: var(--border);
  color: var(--text-soft);
  backdrop-filter: blur(10px);
}
.btn-ghost:hover { background: var(--surface-2); color: var(--text); border-color: var(--border-bright); }
.btn:active { transform: scale(0.97); }
.btn svg { width: 18px; height: 18px; }

.badge-soon {
  font-family: ui-monospace, SFMono-Regular, Menlo, Monaco, Consolas, monospace;
  font-size: 10px;
  letter-spacing: 0.12em;
  padding: 3px 7px;
  border-radius: 6px;
  background: rgba(95, 146, 255, 0.16);
  color: var(--brand-soft);
  border: 1px solid var(--border-bright);
  text-transform: uppercase;
}

/* ---------- Hero ---------- */
.hero { padding: calc(var(--nav-h) + 38px) 0 86px; text-align: center; }
.hero-inner { display: flex; flex-direction: column; align-items: center; }

.hero-icon {
  width: 116px; height: 116px;
  border-radius: 30px;
  margin-bottom: 26px;
  box-shadow: 0 30px 80px -20px rgba(59, 111, 246, 0.7), 0 0 0 1px rgba(255, 255, 255, 0.06);
  animation: float 7s var(--ease-inout) infinite;
}
@keyframes float {
  0%, 100% { transform: translateY(0) rotate(-1deg); }
  50%      { transform: translateY(-14px) rotate(1deg); }
}

.hero h1 { font-size: clamp(2.9rem, 6.4vw, 5rem); font-weight: 600; margin-bottom: 20px; }
.hero h1 .line { display: block; }
.hero p.lead {
  font-size: clamp(1.05rem, 2.2vw, 1.32rem);
  color: var(--text-soft);
  max-width: 620px;
  margin: 0 auto 38px;
}
.hero-actions { display: flex; gap: 15px; flex-wrap: wrap; justify-content: center; }
.hero-note { margin-top: 22px; font-size: 14px; color: var(--text-faint); font-family: ui-monospace, SFMono-Regular, Menlo, Monaco, Consolas, monospace; letter-spacing: 0.04em; }

/* trust strip */
.trust {
  margin-top: 64px;
  display: flex;
  gap: 14px;
  flex-wrap: wrap;
  justify-content: center;
}
.trust-pill {
  display: inline-flex;
  align-items: center;
  gap: 9px;
  padding: 10px 17px;
  border-radius: 100px;
  background: var(--surface);
  border: 1px solid var(--border);
  font-size: 14px;
  color: var(--text-soft);
  backdrop-filter: blur(10px);
}
.trust-pill svg { width: 16px; height: 16px; color: var(--brand-bright); }

/* ---------- Section shell ---------- */
.section-pad { padding: 100px 0; }
.section-head { max-width: 680px; margin-bottom: 58px; }
.section-head.center { margin-left: auto; margin-right: auto; text-align: center; }
.section-head h2 { font-size: clamp(2rem, 4.6vw, 3.2rem); margin: 18px 0 18px; }
.section-head p { color: var(--text-dim); font-size: 1.08rem; }

/* ---------- Feature grid ---------- */
.features { display: grid; grid-template-columns: repeat(12, 1fr); gap: 20px; }
.card {
  position: relative;
  background: linear-gradient(180deg, var(--surface) 0%, rgba(255, 255, 255, 0.012) 100%);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 30px;
  overflow: hidden;
  transition: transform 0.5s var(--ease-expo), border-color 0.5s var(--ease-expo);
  box-shadow: var(--shadow-card);
}
.card::before {
  /* cursor-follow glow */
  content: "";
  position: absolute;
  width: 340px; height: 340px;
  background: radial-gradient(circle, rgba(95, 146, 255, 0.16), transparent 65%);
  left: var(--mx, 50%); top: var(--my, 0%);
  transform: translate(-50%, -50%);
  opacity: 0;
  transition: opacity 0.4s var(--ease-expo);
  pointer-events: none;
}
.card:hover { transform: translateY(-5px); border-color: var(--border-bright); }
.card:hover::before { opacity: 1; }
.card.col-6 { grid-column: span 6; }
.card.col-4 { grid-column: span 4; }
.card.col-5 { grid-column: span 5; }
.card.col-7 { grid-column: span 7; }
.card.col-12 { grid-column: span 12; }

.card-icon {
  width: 50px; height: 50px;
  border-radius: 14px;
  display: grid;
  place-items: center;
  margin-bottom: 22px;
  background: linear-gradient(140deg, rgba(95, 146, 255, 0.22), rgba(110, 91, 240, 0.12));
  border: 1px solid var(--border-bright);
  color: var(--brand-bright);
}
.card-icon svg { width: 24px; height: 24px; }
.card h3 { font-size: 1.35rem; margin-bottom: 11px; font-weight: 600; }
.card p { color: var(--text-dim); font-size: 15.5px; }
.trend-guides { border-top: 1px solid var(--border); border-bottom: 1px solid var(--border); background: linear-gradient(180deg, rgba(59,111,246,0.045), transparent); }
.guide-card { display: flex; min-height: 230px; flex-direction: column; }
.guide-card p { flex: 1; }
.guide-link { margin-top: 24px; color: var(--brand-soft); font-size: 14px; font-weight: 600; }

/* feature-lead (big card) */
.card.feature-lead { display: flex; flex-direction: column; justify-content: space-between; min-height: 300px; }
.card.feature-lead .big { font-size: clamp(1.7rem, 3vw, 2.4rem); font-family: system-ui, -apple-system, BlinkMacSystemFont, "Segoe UI", sans-serif; font-weight: 700; line-height: 1.1; margin-bottom: 14px; letter-spacing: -0.02em; }

/* ---------- Preview showcase ---------- */
.showcase { position: relative; }
.showcase-grid { display: grid; grid-template-columns: 1fr 1fr; gap: 54px; align-items: center; }
.showcase-copy h2 { font-size: clamp(2rem, 4.4vw, 3rem); margin: 18px 0 20px; }
.showcase-copy p { color: var(--text-dim); margin-bottom: 24px; }
.check-list { list-style: none; display: flex; flex-direction: column; gap: 14px; }
.check-list li { display: flex; gap: 13px; align-items: flex-start; color: var(--text-soft); font-size: 15.5px; }
.check-list svg { flex: none; width: 21px; height: 21px; color: var(--brand-bright); margin-top: 1px; }

/* mock window */
.mock {
  position: relative;
  border-radius: 16px;
  background: linear-gradient(180deg, #12141d, #0a0c13);
  border: 1px solid var(--border);
  box-shadow: 0 40px 90px -30px rgba(0, 0, 0, 0.9), 0 0 0 1px rgba(255, 255, 255, 0.03);
  overflow: hidden;
}
.mock-bar { display: flex; align-items: center; gap: 8px; padding: 13px 16px; border-bottom: 1px solid var(--border); background: rgba(255, 255, 255, 0.02); }
.dot { width: 12px; height: 12px; border-radius: 50%; }
.dot.r { background: #ff5f57; } .dot.y { background: #febc2e; } .dot.g { background: #28c840; }
.mock-title { margin-left: 10px; font-size: 12.5px; color: var(--text-faint); font-family: ui-monospace, SFMono-Regular, Menlo, Monaco, Consolas, monospace; }
.mock-body { padding: 26px; display: grid; grid-template-columns: repeat(3, 1fr); gap: 12px; }
.mock-tile {
  aspect-ratio: 1;
  border-radius: 11px;
  background: linear-gradient(145deg, rgba(95,146,255,0.14), rgba(110,91,240,0.06));
  border: 1px solid var(--border);
  display: grid;
  place-items: center;
  color: var(--brand-soft);
  transition: transform 0.4s var(--ease-spring), background 0.4s var(--ease-expo);
}
.mock-tile:hover { transform: scale(1.06); background: linear-gradient(145deg, rgba(95,146,255,0.3), rgba(110,91,240,0.14)); }
.mock-tile svg { width: 30px; height: 30px; }
.mock-filmstrip { display: flex; gap: 8px; padding: 0 26px 24px; }
.mock-filmstrip span { flex: 1; height: 42px; border-radius: 8px; background: var(--surface-2); border: 1px solid var(--border); }
.mock-filmstrip span.active { border-color: var(--brand-bright); box-shadow: 0 0 0 1px var(--brand-bright), 0 0 18px rgba(95,146,255,0.5); }

/* ---------- Format marquee ---------- */
.marquee { overflow: hidden; -webkit-mask-image: linear-gradient(90deg, transparent, #000 12%, #000 88%, transparent); mask-image: linear-gradient(90deg, transparent, #000 12%, #000 88%, transparent); }
.marquee-track { display: flex; gap: 14px; width: max-content; animation: scroll 34s linear infinite; }
.marquee:hover .marquee-track { animation-play-state: paused; }
@keyframes scroll { to { transform: translateX(-50%); } }
.fmt {
  font-family: ui-monospace, SFMono-Regular, Menlo, Monaco, Consolas, monospace;
  font-size: 14px;
  padding: 10px 18px;
  border-radius: 10px;
  background: var(--surface);
  border: 1px solid var(--border);
  color: var(--text-soft);
  white-space: nowrap;
}
.fmt b { color: var(--brand-bright); font-weight: 500; }

/* ---------- Security band ---------- */
.security { border-top: 1px solid var(--border); border-bottom: 1px solid var(--border); background: linear-gradient(180deg, rgba(59,111,246,0.05), transparent); }
.sec-grid { display: grid; grid-template-columns: repeat(4, 1fr); gap: 40px; }
.sec-item { }
.sec-item .k { font-family: system-ui, -apple-system, BlinkMacSystemFont, "Segoe UI", sans-serif; font-size: clamp(2rem, 4vw, 2.8rem); font-weight: 700; background: var(--grad-brand); -webkit-background-clip: text; background-clip: text; color: transparent; }
.sec-item .l { color: var(--text-dim); font-size: 15px; margin-top: 6px; }

/* ---------- FAQ ---------- */
.faq { max-width: 820px; margin: 0 auto; }
.faq-item { border-bottom: 1px solid var(--border); }
.faq-q { width: 100%; text-align: left; background: none; border: 0; color: var(--text); padding: 24px 4px; font-size: 1.12rem; font-weight: 700; font-family: system-ui, -apple-system, BlinkMacSystemFont, "Segoe UI", sans-serif; display: flex; justify-content: space-between; align-items: center; gap: 20px; }
.faq-q .plus { flex: none; width: 24px; height: 24px; position: relative; transition: transform 0.4s var(--ease-spring); }
.faq-q .plus::before, .faq-q .plus::after { content: ""; position: absolute; background: var(--brand-bright); border-radius: 2px; }
.faq-q .plus::before { left: 50%; top: 4px; width: 2px; height: 16px; transform: translateX(-50%); transition: opacity 0.3s var(--ease-expo); }
.faq-q .plus::after { top: 50%; left: 4px; height: 2px; width: 16px; transform: translateY(-50%); }
.faq-item.open .faq-q .plus { transform: rotate(135deg); }
.faq-item.open .faq-q .plus::before { opacity: 0; }
.faq-a { overflow: hidden; max-height: 0; transition: max-height 0.5s var(--ease-expo); }
.faq-a p { color: var(--text-dim); padding: 0 4px 24px; font-size: 15.5px; }

/* ---------- CTA ---------- */
.cta-final { text-align: center; }
.cta-box {
  position: relative;
  border-radius: 30px;
  padding: 72px 40px;
  overflow: hidden;
  border: 1px solid var(--border-bright);
  background:
    radial-gradient(60% 120% at 50% 0%, rgba(59, 111, 246, 0.22), transparent 70%),
    linear-gradient(180deg, rgba(255, 255, 255, 0.04), rgba(255, 255, 255, 0.01));
}
.cta-box h2 { font-size: clamp(2.2rem, 5vw, 3.6rem); margin-bottom: 18px; }
.cta-box p { color: var(--text-soft); max-width: 520px; margin: 0 auto 34px; }
.cta-glow { position: absolute; width: 460px; height: 460px; border-radius: 50%; background: radial-gradient(circle, rgba(59,111,246,0.4), transparent 60%); left: 50%; bottom: -60%; transform: translateX(-50%); filter: blur(40px); pointer-events: none; animation: pulse 6s var(--ease-inout) infinite; }
@keyframes pulse { 0%,100% { opacity: 0.6; } 50% { opacity: 1; } }

/* ---------- Footer ---------- */
.footer { border-top: 1px solid var(--border); padding: 60px 0 44px; }
.footer-grid { display: flex; justify-content: space-between; gap: 40px; flex-wrap: wrap; margin-bottom: 44px; }
.footer-brand { max-width: 300px; }
.footer-brand .brand { margin-bottom: 16px; }
.footer-brand p { color: var(--text-dim); font-size: 14.5px; }
.footer-cols { display: flex; gap: 70px; flex-wrap: wrap; }
.footer-col h4 { font-family: ui-monospace, SFMono-Regular, Menlo, Monaco, Consolas, monospace; font-size: 11px; letter-spacing: 0.16em; text-transform: uppercase; color: var(--text-faint); margin-bottom: 16px; font-weight: 500; }
.footer-col a { display: block; color: var(--text-dim); font-size: 15px; margin-bottom: 11px; transition: color 0.25s var(--ease-expo); }
.footer-col a:hover { color: var(--brand-soft); }
.footer-bottom { display: flex; justify-content: space-between; gap: 16px; flex-wrap: wrap; padding-top: 28px; border-top: 1px solid var(--border); color: var(--text-faint); font-size: 13.5px; }

/* ---------- Reveal animation ---------- */
[data-reveal] { opacity: 0; transform: translateY(28px); transition: opacity 0.9s var(--ease-expo), transform 0.9s var(--ease-expo); }
[data-reveal].in { opacity: 1; transform: none; }
[data-reveal-delay="1"] { transition-delay: 0.08s; }
[data-reveal-delay="2"] { transition-delay: 0.16s; }
[data-reveal-delay="3"] { transition-delay: 0.24s; }
[data-reveal-delay="4"] { transition-delay: 0.32s; }

/* ---------- Legal / content pages ---------- */
.doc { padding: calc(var(--nav-h) + 80px) 0 100px; }
.doc-inner { max-width: 780px; margin: 0 auto; }
.doc h1 { font-size: clamp(2.4rem, 5vw, 3.4rem); margin-bottom: 14px; }
.doc .updated { font-family: ui-monospace, SFMono-Regular, Menlo, Monaco, Consolas, monospace; font-size: 13px; color: var(--text-faint); margin-bottom: 44px; letter-spacing: 0.03em; }
.doc h2 { font-size: 1.5rem; margin: 44px 0 16px; }
.doc h3 { font-size: 1.15rem; margin: 28px 0 10px; color: var(--text-soft); }
.doc p, .doc li { color: var(--text-soft); font-size: 16px; margin-bottom: 14px; }
.doc ul, .doc ol { padding-left: 22px; margin-bottom: 18px; }
.doc li { margin-bottom: 8px; }
.doc a { color: var(--brand-soft); border-bottom: 1px solid rgba(143, 176, 255, 0.3); }
.doc a:hover { border-color: var(--brand-soft); }
.doc strong { color: var(--text); }
.guide-page .doc-inner { max-width: 860px; }
.guide-page .guide-lead { color: var(--text-soft); font-size: 1.18rem; margin: 20px 0 26px; }
.guide-meta { color: var(--text-faint); font-family: ui-monospace, SFMono-Regular, Menlo, Monaco, Consolas, monospace; font-size: 13px; margin-bottom: 34px; }
.breadcrumb { display: flex; gap: 9px; align-items: center; color: var(--text-faint); font-size: 14px; margin-bottom: 26px; }
.breadcrumb a { border: 0; }
.guide-toc { display: grid; grid-template-columns: repeat(2, 1fr); gap: 10px 28px; list-style: none; padding: 0 !important; }
.guide-toc li { margin: 0; }
.guide-toc a { display: block; padding: 9px 0; }
.comparison-wrap { overflow-x: auto; margin: 24px 0 34px; border: 1px solid var(--border); border-radius: 16px; }
.comparison { width: 100%; border-collapse: collapse; min-width: 680px; }
.comparison th, .comparison td { padding: 16px 18px; text-align: left; vertical-align: top; border-bottom: 1px solid var(--border); }
.comparison th { color: var(--text); background: rgba(255,255,255,0.04); font-size: 14px; }
.comparison td { color: var(--text-soft); font-size: 15px; }
.comparison tr:last-child td { border-bottom: 0; }
.guide-section { scroll-margin-top: 90px; }
.guide-cta { margin-top: 54px; padding: 34px; border: 1px solid var(--border-bright); border-radius: 20px; background: linear-gradient(145deg, rgba(59,111,246,0.12), rgba(110,91,240,0.04)); }
.guide-cta h2 { margin-top: 0; }
.guide-cta .btn { border-bottom: 0; margin-top: 10px; }
.related-links { display: grid; grid-template-columns: repeat(2, 1fr); gap: 14px; margin-top: 20px; }
.related-links a { padding: 18px; border: 1px solid var(--border); border-radius: 14px; background: var(--surface); }
.callout {
  border: 1px solid var(--border-bright);
  background: linear-gradient(180deg, rgba(59, 111, 246, 0.08), transparent);
  border-radius: 16px;
  padding: 22px 24px;
  margin: 24px 0;
}
.callout p:last-child { margin-bottom: 0; }

/* ---------- Responsive ---------- */
@media (max-width: 900px) {
  .nav-links { display: none; }
  .nav-toggle { display: block; }
  .features { grid-template-columns: repeat(6, 1fr); }
  .card.col-6, .card.col-5, .card.col-7 { grid-column: span 6; }
  .card.col-4 { grid-column: span 3; }
  .showcase-grid { grid-template-columns: 1fr; gap: 40px; }
  .sec-grid { grid-template-columns: repeat(2, 1fr); gap: 32px; }
}
@media (max-width: 620px) {
  body { font-size: 16px; }
  .wrap { padding: 0 20px; }
  .nav-cta { gap: 8px; }
  .nav .btn { padding: 9px 12px; font-size: 13px; white-space: nowrap; }
  .nav .btn svg { width: 15px; height: 15px; }
  .lang-toggle { min-width: 40px; padding: 0 9px; white-space: nowrap; }
  .section-pad { padding: 76px 0; }
  .card.col-4 { grid-column: span 6; }
  .mock-body { grid-template-columns: repeat(3, 1fr); }
  .footer-cols { gap: 40px; }
  .hero-icon { width: 108px; height: 108px; }
  .guide-toc, .related-links { grid-template-columns: 1fr; }
  .guide-cta { padding: 26px 22px; }
}

/* ---------- Bilingual toggle ---------- */
/* Content is authored twice (data-lang="en" / data-lang="zh"); the active
   language on <html data-lang> decides which copy shows. */
html[data-lang="en"] [data-lang="zh"],
html[data-lang="zh"] [data-lang="en"] { display: none !important; }

.lang-toggle {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  min-width: 46px;
  height: 38px;
  padding: 0 13px;
  border-radius: 11px;
  background: var(--surface);
  border: 1px solid var(--border);
  color: var(--text-soft);
  font-family: ui-monospace, SFMono-Regular, Menlo, Monaco, Consolas, monospace;
  font-size: 13px;
  font-weight: 500;
  letter-spacing: 0.02em;
  transition: color 0.25s var(--ease-expo), border-color 0.25s var(--ease-expo), background 0.25s var(--ease-expo);
}
.lang-toggle:hover { color: var(--text); border-color: var(--border-bright); background: var(--surface-2); }

/* keep the Chinese display font pleasant */
html[data-lang="zh"] body { font-family: system-ui, -apple-system, BlinkMacSystemFont, "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei", sans-serif; }
html[data-lang="zh"] h1,
html[data-lang="zh"] h2,
html[data-lang="zh"] h3,
html[data-lang="zh"] .card.feature-lead .big,
html[data-lang="zh"] .faq-q { font-family: system-ui, -apple-system, BlinkMacSystemFont, "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei", sans-serif; letter-spacing: -0.01em; }

/* ---------- Reduced motion ---------- */
@media (prefers-reduced-motion: reduce) {
  *, *::before, *::after { animation: none !important; transition-duration: 0.01ms !important; }
  [data-reveal] { opacity: 1; transform: none; }
  html { scroll-behavior: auto; }
}