:root {
  --bg: #fff;
  --ink: #111;
  --muted: #5c5c5c;
  --soft: #8a8a8a;
  --line: #ececec;
  --brand: #0066fc;
  --brand-deep: #0052cc;
  --brand-soft: #e8f1ff;
  --mint: #f3f8ff;
  --mint-2: #eaf3ff;
  --shadow: 0 24px 80px rgba(17, 40, 80, .08);
  --max: 1180px;
  --nav-h: 64px;
  --legal-banner-h: 44px;
  --safe-top: env(safe-area-inset-top, 0px);
}
* { box-sizing: border-box; }
html { scroll-behavior: smooth; }
body {
  margin: 0;
  min-width: 320px;
  padding-top: calc(var(--safe-top) + var(--legal-banner-h) + var(--nav-h));
  color: var(--ink);
  background: var(--bg);
  font: 16px/1.65 "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei", system-ui, sans-serif;
  -webkit-font-smoothing: antialiased;
  overflow-x: hidden;
}
a { color: inherit; text-decoration: none; }
button { color: inherit; font: inherit; background: none; border: 0; cursor: pointer; }
img, svg { display: block; }
.wrap { width: min(var(--max), calc(100% - 48px)); margin-inline: auto; }

.legal-banner {
  position: fixed;
  top: var(--safe-top);
  left: 0;
  right: 0;
  z-index: 200;
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 8px;
  padding: 8px 16px;
  background: #fef08a;
  border-bottom: 1px solid #facc15;
  color: #713f12;
  font-size: 0.75rem;
  font-weight: 500;
  line-height: 1.45;
  text-align: center;
  box-sizing: border-box;
}
.legal-banner-icon { flex-shrink: 0; font-size: 0.85rem; line-height: 1; }
.legal-banner-text {
  max-width: 960px;
  min-width: 0;
  overflow-wrap: anywhere;
  word-break: break-word;
}

.header {
  position: fixed;
  top: calc(var(--safe-top) + var(--legal-banner-h));
  left: 0;
  right: 0;
  z-index: 80;
  height: var(--nav-h);
  background: rgba(255,255,255,.86);
  backdrop-filter: blur(18px);
  border-bottom: 1px solid transparent;
}
.header.scrolled { border-bottom-color: var(--line); }
.nav {
  position: relative;
  height: 100%;
  display: flex;
  align-items: center;
  justify-content: flex-start;
  gap: 24px;
}
.brand { display: flex; align-items: center; gap: 10px; font-weight: 700; letter-spacing: -.02em; }
.brand img { width: 32px; height: 32px; }
.nav-menu { display: flex; align-items: center; gap: 32px; margin: 0 0 0 auto; padding: 0; list-style: none; }
.nav-menu a { font-size: 14px; color: #333; }
.nav-menu a:hover, .nav-menu a.active { color: var(--brand); }
.nav-menu a.active { font-weight: 600; }
.nav-menu-cta { display: none; }
.nav-actions { display: flex; align-items: center; gap: 8px; }
.nav-toggle { display: none; width: 40px; height: 40px; place-items: center; }
.nav-toggle svg { width: 20px; }

.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 8px;
  min-height: 40px;
  padding: 8px 18px;
  border-radius: 999px;
  font-size: 14px;
  font-weight: 500;
  transition: transform .2s, background .2s, color .2s;
}
.btn:hover { transform: translateY(-1px); }
.btn-black { color: #fff; background: #1a1a1a; }
.btn-black:hover { background: #000; }
.btn-ghost { color: #333; }
.btn-link { color: var(--brand); font-weight: 500; }
.btn-link:hover { color: var(--brand-deep); }
.btn-lg { min-height: 48px; padding: 12px 24px; font-size: 16px; }

.hero {
  position: relative;
  overflow: hidden;
  padding: 72px 0 8px;
}
.hero-glow {
  position: absolute;
  left: -8%;
  bottom: 8%;
  width: 48%;
  height: 70%;
  background: radial-gradient(circle at 40% 50%, rgba(0,102,252,.16), rgba(120,190,255,.08) 42%, transparent 70%);
  pointer-events: none;
}
.hero-grid {
  display: grid;
  grid-template-columns: .9fr 1.1fr;
  gap: 48px;
  align-items: start;
}
.hero h1 {
  margin: 0;
  font-size: clamp(4.2rem, 8.5vw, 7.4rem);
  line-height: 1.05;
  letter-spacing: -.05em;
  font-weight: 700;
  overflow: visible;
}
.hero-side { padding-top: 18px; max-width: 400px; justify-self: end; text-align: right; }
.hero-side p {
  margin: 0 0 28px;
  color: var(--muted);
  font-size: 15px;
  line-height: 1.85;
}
.hero-actions { display: flex; flex-direction: column; align-items: flex-end; gap: 14px; }

.hero-stage {
  position: relative;
  margin-top: 36px;
  overflow: hidden;
  border: 1px solid #e6eaf0;
  border-radius: 32px;
  box-shadow: var(--shadow);
}
.hero-shot {
  display: block;
  width: 100%;
  height: auto;
}

section { padding: 88px 0; }
#features, #pricing, #ai, #secure {
  scroll-margin-top: calc(var(--safe-top) + var(--nav-h) + var(--legal-banner-h) + 12px);
}
.badge {
  width: fit-content;
  margin: 0 auto 22px;
  padding: 7px 14px;
  border-radius: 999px;
  color: var(--brand);
  background: var(--brand-soft);
  font-size: 12px;
  font-weight: 550;
  letter-spacing: .04em;
}
.badge.left { margin-left: 0; }
.sec-title {
  margin: 0 auto;
  max-width: 900px;
  text-align: center;
  font-size: clamp(2.2rem, 4.6vw, 3.6rem);
  line-height: 1.15;
  letter-spacing: -.045em;
  font-weight: 700;
}
.sec-desc {
  max-width: 640px;
  margin: 16px auto 0;
  text-align: center;
  color: var(--muted);
  font-size: 16px;
}

.tabs {
  position: relative;
  width: fit-content;
  margin: 36px auto 28px;
  padding: 5px;
  display: flex;
  gap: 2px;
  border-radius: 999px;
  background: #f2f3f5;
}
.tabs-ink {
  position: absolute;
  top: 5px;
  left: 0;
  height: calc(100% - 10px);
  border-radius: 999px;
  background: #fff;
  box-shadow: 0 4px 16px rgba(0,0,0,.06);
  pointer-events: none;
  transition: transform .45s cubic-bezier(.22, 1, .36, 1), width .45s cubic-bezier(.22, 1, .36, 1);
}
.tabs button {
  position: relative;
  z-index: 1;
  min-width: 88px;
  padding: 10px 22px;
  border-radius: 999px;
  color: #666;
  font-size: 15px;
  background: transparent;
  transition: color .3s;
}
.tabs button[aria-selected="true"] {
  color: #111;
  font-weight: 600;
}
.scene-stage {
  position: relative;
  overflow: hidden;
  border-radius: 36px;
  background: var(--mint);
  transition: height .5s cubic-bezier(.22, 1, .36, 1);
}
.scene {
  display: none;
  grid-template-columns: minmax(0, 1fr) max-content;
  align-items: center;
  width: 100%;
}
.scene.active,
.scene.is-in,
.scene.is-out {
  display: grid;
}
.scene.active { position: relative; }
.scene.is-in,
.scene.is-out {
  position: absolute;
  left: 0;
  top: 0;
  pointer-events: none;
}
.scene-copy { padding: 56px 28px 56px 48px; }
.scene-copy h3 {
  margin: 0;
  font-size: clamp(1.55rem, 2.5vw, 2.15rem);
  line-height: 1.28;
  letter-spacing: -.035em;
}
.scene-copy p { margin: 16px 0 0; color: var(--muted); font-size: 15px; }
.scene-visual {
  display: flex;
  align-items: center;
  justify-content: center;
  padding: 32px 32px 32px 8px;
}
.scene-copy,
.scene-shot {
  transition: opacity .45s cubic-bezier(.22, 1, .36, 1), transform .55s cubic-bezier(.22, 1, .36, 1);
}
.scene-shot { transition-delay: .06s; }
.scene.is-out .scene-copy,
.scene.is-out .scene-shot {
  opacity: 0;
  transform: translateX(var(--out-x, -28px));
}
.scene.is-in .scene-copy,
.scene.is-in .scene-shot {
  opacity: 0;
  transform: translateX(var(--in-x, 36px));
}
.scene.active .scene-copy,
.scene.active .scene-shot {
  opacity: 1;
  transform: none;
}
.scene-shot {
  display: block;
  width: auto;
  height: auto;
  max-width: none;
  border: 1px solid #e4eaf3;
  border-radius: 32px;
  background: #fff;
  box-shadow: var(--shadow);
}

.eco {
  position: relative;
  overflow: hidden;
  padding: 100px 0 80px;
  background:
    radial-gradient(ellipse 80% 60% at 50% -10%, #f7fbff, transparent 60%),
    linear-gradient(#f8fafc, #fff);
}
.eco::before {
  content: "";
  position: absolute; inset: 0;
  background:
    repeating-linear-gradient(90deg, rgba(15,40,80,.035) 0 1px, transparent 1px 48px),
    repeating-linear-gradient(0deg, rgba(15,40,80,.03) 0 1px, transparent 1px 48px);
  mask-image: linear-gradient(to bottom, transparent, #000 18%, #000 70%, transparent);
  transform: perspective(700px) rotateX(58deg) scale(1.4);
  transform-origin: 50% 0;
  pointer-events: none;
}
.eco .wrap { position: relative; }
.eco-title { text-align: right; max-width: 720px; margin-left: auto; }
.eco-title h2 { margin: 0; font-size: clamp(2rem, 4vw, 3.1rem); letter-spacing: -.04em; line-height: 1.2; }
.eco-title p { margin: 14px 0 0; color: var(--muted); }
.eco-row {
  margin-top: 48px;
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 14px;
}
.eco-card {
  padding: 22px 20px;
  border-radius: 18px;
  background: #fff;
  box-shadow: 0 10px 30px rgba(15, 40, 80, .05);
  display: flex; align-items: center; gap: 12px;
  font-weight: 600;
}
.eco-ico {
  width: 42px; height: 42px; border-radius: 12px;
  display: grid; place-items: center;
  background: var(--brand-soft); color: var(--brand);
  flex: none;
}
.eco-ico svg { width: 20px; }

.secure-shell {
  padding: 56px 48px 28px;
  border-radius: 36px;
  background:
    linear-gradient(180deg, rgba(255,255,255,.4), transparent 40%),
    repeating-linear-gradient(90deg, rgba(0,102,252,.05) 0 1px, transparent 1px 42px),
    repeating-linear-gradient(0deg, rgba(0,102,252,.05) 0 1px, transparent 1px 42px),
    var(--mint-2);
}
.secure-shell .badge { margin-left: 0; }
.secure-shell .sec-title, .secure-shell .sec-desc { text-align: left; margin-left: 0; }
.secure-list { margin-top: 28px; display: grid; gap: 14px; }
.secure-card {
  padding: 28px 30px 32px;
  border-radius: 22px;
  background: #fff;
}
.secure-card svg { width: 28px; color: var(--brand); }
.secure-card h3 { margin: 22px 0 8px; font-size: 20px; }
.secure-card p { margin: 0; color: var(--muted); }

.start .sec-title { letter-spacing: -.04em; }
.plan-row {
  margin-top: 40px;
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 14px;
}
.plan {
  padding: 22px 20px 24px;
  border-radius: 18px;
  background: #f7f7f8;
  text-align: left;
  transition: transform .2s, background .2s;
}
.plan:hover { transform: translateY(-3px); background: #f0f2f5; }
.plan small { color: var(--soft); font-size: 12px; }
.plan strong { display: block; margin: 10px 0 4px; font-size: 22px; letter-spacing: -.03em; }
.plan em { font-style: normal; color: var(--muted); font-size: 13px; }
.plan.hot { background: #1a1a1a; color: #fff; }
.plan.hot small, .plan.hot em { color: #bdbdbd; }
.plan.hot:hover { background: #111; }
.start-note { margin: 28px 0 0; text-align: center; color: var(--muted); font-size: 14px; }

.site-footer { padding: 48px 0 36px; border-top: 1px solid var(--line); }
.foot-grid { display: grid; grid-template-columns: repeat(4, 1fr); gap: 24px; }
.site-footer h4 { margin: 0 0 14px; font-size: 14px; }
.site-footer a { display: block; margin: 8px 0; color: #666; font-size: 14px; }
.site-footer a:hover { color: var(--ink); }
.copy { margin: 36px 0 0; color: var(--soft); font-size: 12px; }

.reveal { opacity: 0; transform: translateY(16px); transition: opacity .6s ease, transform .6s ease; }
.reveal.visible { opacity: 1; transform: none; }

@media (prefers-reduced-motion: reduce) {
  html { scroll-behavior: auto; }
  .reveal { opacity: 1; transform: none; transition: none; }
  .tabs-ink, .scene-stage, .scene-copy, .scene-shot { transition: none; }
}
@media (max-width: 980px) {
  .nav { gap: 12px; }
  .nav-actions { margin-left: auto; }
  .nav-cta-desktop { display: none; }
  .nav-menu { display: none; }
  .header { z-index: 80; }
  .nav.open .nav-menu {
    display: grid;
    position: absolute;
    left: 50%;
    right: auto;
    top: 100%;
    width: 100vw;
    margin: 0;
    padding: 8px 24px 20px;
    background: #fff;
    border-bottom: 1px solid var(--line);
    gap: 2px;
    transform: translateX(-50%);
    box-shadow: 0 16px 40px rgba(17, 40, 80, .08);
  }
  .nav.open .nav-menu a { padding: 12px 4px; }
  .nav-menu-cta {
    display: grid;
    gap: 8px;
    margin-top: 8px;
    padding-top: 12px;
    border-top: 1px solid var(--line);
  }
  .nav-menu-cta .btn { width: 100%; }
  .nav-menu a.btn-ghost {
    color: #111;
    background: #f4f4f5;
  }
  .nav-menu a.btn-black,
  .nav-menu a.btn-black:hover {
    color: #fff;
  }
  .nav-toggle { display: grid; }
  .hero {
    overflow: visible;
    padding-top: 32px;
    min-height: auto;
  }
  .hero-grid { grid-template-columns: 1fr; gap: 12px; }
  .hero h1 {
    font-size: 2.6rem;
    line-height: 1.25;
    letter-spacing: 0;
  }
  .hero-side { justify-self: start; max-width: none; padding-top: 4px; text-align: left; }
  .hero-actions { align-items: flex-start; }
  .hero-stage { border-radius: 24px; }
  .scene.active, .scene.is-in, .scene.is-out, .eco-row, .plan-row, .foot-grid { grid-template-columns: 1fr 1fr; }
  .scene { grid-template-columns: 1fr; }
  .scene-copy { padding: 36px 28px 12px; }
  .scene-visual { padding: 12px 24px 28px; }
  .scene-shot { max-width: 100%; }
  .secure-shell { padding: 32px 22px 16px; }
  .eco-title { text-align: left; margin-left: 0; }
}
@media (max-width: 640px) {
  .wrap { width: min(100% - 28px, var(--max)); }
  .legal-banner {
    gap: 6px;
    padding: 8px 12px;
    font-size: 0.68rem;
    line-height: 1.5;
  }
  .hero { padding: 24px 0 8px; }
  .hero h1 {
    font-size: 2.35rem;
    line-height: 1.3;
    letter-spacing: 0;
  }
  .hero-side p { font-size: 14px; line-height: 1.75; }
  .hero-stage { margin-top: 24px; border-radius: 20px; }
  section { padding: 64px 0; }
  .sec-title { font-size: clamp(1.7rem, 7vw, 2.2rem); }
  .tabs {
    width: 100%;
    max-width: 100%;
    overflow-x: auto;
    scrollbar-width: none;
  }
  .tabs::-webkit-scrollbar { display: none; }
  .scene.active, .scene.is-in, .scene.is-out, .eco-row, .plan-row, .foot-grid { grid-template-columns: 1fr; }
  .scene-copy { padding: 28px 20px 8px; }
  .scene-visual { min-height: 0; padding: 8px 16px 24px; }
  .scene-shot { max-width: 100%; border-radius: 24px; }
  .btn-lg { width: 100%; }
  .eco { padding: 64px 0 48px; }
}