/* =========================================================================
   火采 AI · 浏览器自动化插件 — 企业级官网样式
   Design System: "Dark Tech / Enterprise AI"
   Distinct from sibling products (light themes). Sharp edges + glass + neon accents.
   ========================================================================= */

/* ---------- CSS Variables ---------- */
:root {
  /* Core palette — deep ink navy + electric blue/violet */
  --bg-0: #05060f;
  --bg-1: #0a0d1f;
  --bg-2: #10142a;
  --bg-3: #161b38;
  --surface: rgba(255, 255, 255, 0.035);
  --surface-2: rgba(255, 255, 255, 0.06);
  --border: rgba(148, 163, 255, 0.14);
  --border-strong: rgba(148, 163, 255, 0.3);

  /* Accent — electric blue to violet gradient */
  --accent: #5b8cff;
  --accent-2: #a678ff;
  --accent-3: #22d3ee;
  --grad: linear-gradient(120deg, #4f7cff 0%, #a678ff 55%, #22d3ee 110%);
  --grad-soft: linear-gradient(120deg, rgba(79,124,255,.16), rgba(166,120,255,.16));

  /* Text */
  --txt: #eef1ff;
  --txt-dim: #a3abcc;
  --txt-faint: #6b739a;

  /* Misc */
  --radius: 4px;          /* sharp, enterprise */
  --radius-lg: 12px;
  --font-sans: "Inter", "PingFang SC", "Microsoft YaHei", -apple-system, system-ui, sans-serif;
  --font-mono: "JetBrains Mono", "SF Mono", "Consolas", monospace;
  --shadow: 0 24px 60px rgba(3, 6, 24, 0.55);
  --glow: 0 0 0 1px rgba(79,124,255,.25), 0 20px 60px rgba(79,124,255,.18);
  --container: 1240px;
}

/* ---------- Reset & Base ---------- */
*, *::before, *::after { box-sizing: border-box; margin: 0; padding: 0; }
html { scroll-behavior: smooth; scroll-padding-top: 88px; }
body {
  font-family: var(--font-sans);
  background: var(--bg-0);
  color: var(--txt);
  line-height: 1.7;
  font-size: 16px;
  -webkit-font-smoothing: antialiased;
  overflow-x: hidden;
}
a { color: inherit; text-decoration: none; }
img { max-width: 100%; display: block; }
ul { list-style: none; }
::selection { background: rgba(79,124,255,.35); color: #fff; }

/* Scrollbar */
::-webkit-scrollbar { width: 10px; height: 10px; }
::-webkit-scrollbar-track { background: var(--bg-1); }
::-webkit-scrollbar-thumb { background: #232a4d; border-radius: 6px; }
::-webkit-scrollbar-thumb:hover { background: #34406e; }

/* ---------- Animated Background Grid ---------- */
.bg-grid {
  position: fixed;
  inset: 0;
  z-index: -2;
  background-image:
    linear-gradient(rgba(79,124,255,.06) 1px, transparent 1px),
    linear-gradient(90deg, rgba(79,124,255,.06) 1px, transparent 1px);
  background-size: 54px 54px;
  mask-image: radial-gradient(ellipse 90% 70% at 50% 0%, #000 0%, transparent 100%);
}
.bg-glow {
  position: fixed;
  z-index: -1;
  border-radius: 50%;
  filter: blur(120px);
  opacity: .5;
  pointer-events: none;
}
.bg-glow.g1 { width: 520px; height: 520px; background: #3158d8; top: -180px; left: 8%; }
.bg-glow.g2 { width: 460px; height: 460px; background: #7a3ee0; top: 10%; right: -120px; }
.bg-glow.g3 { width: 380px; height: 380px; background: #0e7f9b; bottom: 0; left: 30%; }

/* ---------- Layout Utilities ---------- */
.container { max-width: var(--container); margin: 0 auto; padding: 0 28px; }
.section { padding: 96px 0; position: relative; }
.section-alt { background: linear-gradient(180deg, var(--bg-1), var(--bg-0)); }

/* ---------- Navbar ---------- */
.nav {
  position: fixed;
  top: 0; left: 0; right: 0;
  z-index: 100;
  padding: 16px 0;
  transition: all .35s ease;
}
.nav.scrolled {
  background: rgba(5, 6, 15, .82);
  backdrop-filter: blur(18px);
  border-bottom: 1px solid var(--border);
  padding: 10px 0;
}
.nav .container { display: flex; align-items: center; justify-content: space-between; }
.brand { display: flex; align-items: center; gap: 12px; }
.brand img { height: 40px; width: auto; filter: drop-shadow(0 0 12px rgba(255,120,180,.5)); }
.brand-name { font-size: 20px; font-weight: 800; letter-spacing: .3px; }
.brand-name .accent-t { background: var(--grad); -webkit-background-clip: text; background-clip: text; color: transparent; }
.nav-links { display: flex; align-items: center; gap: 6px; }
.nav-links a {
  color: var(--txt-dim);
  font-size: 15px;
  padding: 8px 14px;
  border-radius: var(--radius);
  transition: all .2s;
  position: relative;
}
.nav-links a:hover { color: var(--txt); background: var(--surface-2); }
.nav-cta { display: flex; align-items: center; gap: 12px; }
.nav-toggle {
  display: none;
  background: none; border: 1px solid var(--border);
  color: var(--txt); font-size: 22px;
  width: 42px; height: 42px; border-radius: var(--radius);
  cursor: pointer;
}

/* ---------- Buttons ---------- */
.btn {
  display: inline-flex; align-items: center; gap: 8px;
  font-size: 15px; font-weight: 600;
  padding: 12px 22px;
  border-radius: var(--radius);
  border: 1px solid transparent;
  cursor: pointer;
  transition: all .25s;
  white-space: nowrap;
}
.btn-primary {
  background: var(--grad);
  color: #fff;
  box-shadow: 0 8px 30px rgba(79,124,255,.35);
}
.btn-primary:hover { transform: translateY(-2px); box-shadow: 0 14px 40px rgba(120,90,255,.5); }
.btn-ghost {
  background: transparent;
  color: var(--txt);
  border-color: var(--border-strong);
}
.btn-ghost:hover { background: var(--surface-2); border-color: var(--accent); }
.btn-lg { padding: 15px 30px; font-size: 16px; }
.btn-sm { padding: 8px 14px; font-size: 14px; }

/* ---------- Hero ---------- */
.hero {
  position: relative;
  padding: 180px 0 100px;
  text-align: center;
  overflow: hidden;
}
.hero-badge {
  display: inline-flex; align-items: center; gap: 8px;
  padding: 8px 18px;
  border: 1px solid var(--border-strong);
  border-radius: 100px;
  background: var(--surface);
  font-size: 14px;
  color: var(--accent-3);
  font-family: var(--font-mono);
  margin-bottom: 28px;
  letter-spacing: .4px;
}
.hero-badge .dot {
  width: 8px; height: 8px; border-radius: 50%;
  background: #22d3ee;
  box-shadow: 0 0 12px #22d3ee;
  animation: pulse 2s infinite;
}
@keyframes pulse { 0%,100% { opacity: 1; } 50% { opacity: .3; } }
.hero h1 {
  font-size: clamp(42px, 6vw, 76px);
  font-weight: 800;
  line-height: 1.12;
  letter-spacing: -1.5px;
  margin-bottom: 24px;
}
.hero h1 .grad {
  background: var(--grad);
  -webkit-background-clip: text; background-clip: text;
  color: transparent;
}
.hero-sub {
  font-size: clamp(17px, 2vw, 22px);
  color: var(--txt-dim);
  max-width: 760px;
  margin: 0 auto 40px;
}
.hero-actions { display: flex; gap: 16px; justify-content: center; flex-wrap: wrap; margin-bottom: 48px; }
.hero-stats {
  display: flex; gap: 60px; justify-content: center; flex-wrap: wrap;
  border-top: 1px solid var(--border);
  padding-top: 40px;
  max-width: 900px; margin: 0 auto;
}
.stat { text-align: center; }
.stat b { display: block; font-size: 34px; font-weight: 800; background: var(--grad); -webkit-background-clip: text; background-clip: text; color: transparent; }
.stat span { font-size: 14px; color: var(--txt-faint); }

/* Hero terminal mock */
.hero-terminal {
  margin: 56px auto 0;
  max-width: 860px;
  text-align: left;
  border: 1px solid var(--border-strong);
  border-radius: var(--radius-lg);
  background: rgba(8, 10, 26, .85);
  box-shadow: var(--glow);
  overflow: hidden;
  backdrop-filter: blur(8px);
}
.term-bar {
  display: flex; align-items: center; gap: 8px;
  padding: 14px 18px;
  border-bottom: 1px solid var(--border);
  background: var(--bg-2);
}
.term-bar .dotc { width: 12px; height: 12px; border-radius: 50%; }
.term-bar .dotc.r { background: #ff5f57; }
.term-bar .dotc.y { background: #febc2e; }
.term-bar .dotc.g { background: #28c840; }
.term-bar .title { margin-left: 12px; font-family: var(--font-mono); font-size: 13px; color: var(--txt-faint); }
.term-body { padding: 24px 26px; font-family: var(--font-mono); font-size: 14px; line-height: 2; }
.term-body .p { color: var(--txt-faint); }
.term-body .cmd { color: #7dd3fc; }
.term-body .ok { color: #34d399; }
.term-body .c { color: var(--accent-2); }
.cursor { display: inline-block; width: 8px; height: 16px; background: var(--accent); vertical-align: middle; animation: blink 1s infinite; }
@keyframes blink { 0%,100% { opacity: 1; } 50% { opacity: 0; } }

/* ---------- Section Headers ---------- */
.sec-head { text-align: center; max-width: 760px; margin: 0 auto 64px; }
.sec-tag {
  font-family: var(--font-mono);
  color: var(--accent-3);
  font-size: 14px;
  letter-spacing: 2px;
  text-transform: uppercase;
  margin-bottom: 14px;
  display: inline-block;
}
.sec-title { font-size: clamp(30px, 4vw, 46px); font-weight: 800; letter-spacing: -.8px; line-height: 1.2; margin-bottom: 18px; }
.sec-title .grad { background: var(--grad); -webkit-background-clip: text; background-clip: text; color: transparent; }
.sec-desc { color: var(--txt-dim); font-size: 17px; }

/* ---------- Feature Cards ---------- */
.feature-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 20px;
}
.f-card {
  position: relative;
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--radius-lg);
  padding: 32px 28px;
  transition: all .3s;
  overflow: hidden;
}
.f-card::before {
  content: "";
  position: absolute; top: 0; left: 0; right: 0; height: 2px;
  background: var(--grad);
  transform: scaleX(0);
  transform-origin: left;
  transition: transform .4s ease;
}
.f-card:hover { border-color: var(--border-strong); background: var(--surface-2); transform: translateY(-6px); box-shadow: var(--shadow); }
.f-card:hover::before { transform: scaleX(1); }
.f-icon {
  width: 52px; height: 52px;
  display: grid; place-items: center;
  font-size: 24px;
  color: #fff;
  background: var(--grad-soft);
  border: 1px solid var(--border-strong);
  border-radius: var(--radius);
  margin-bottom: 20px;
  background-clip: padding-box;
}
.f-card h3 { font-size: 20px; font-weight: 700; margin-bottom: 12px; }
.f-card p { color: var(--txt-dim); font-size: 15px; }

/* ---------- Scenario (Application) ---------- */
.scenario-grid { display: grid; grid-template-columns: repeat(2, 1fr); gap: 20px; }
.scenario {
  display: flex; gap: 20px;
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--radius-lg);
  padding: 28px;
  transition: all .3s;
}
.scenario:hover { border-color: var(--border-strong); background: var(--surface-2); transform: translateY(-4px); }
.sc-ico { flex-shrink: 0; width: 56px; height: 56px; display: grid; place-items: center; font-size: 26px; color: var(--accent-3); background: var(--grad-soft); border-radius: var(--radius); border: 1px solid var(--border); }
.scenario h4 { font-size: 19px; margin-bottom: 8px; }
.scenario p { color: var(--txt-dim); font-size: 15px; }
.scenario .tag {
  display: inline-block; margin-top: 12px; padding: 3px 10px; font-size: 12px;
  font-family: var(--font-mono); color: var(--accent-3); background: var(--grad-soft); border-radius: 100px; border: 1px solid var(--border);
}

/* ---------- Steps / How it works ---------- */
.steps { display: grid; grid-template-columns: repeat(4, 1fr); gap: 20px; counter-reset: step; }
.step { position: relative; background: var(--surface); border: 1px solid var(--border); border-radius: var(--radius-lg); padding: 28px 24px; transition: all .3s; }
.step:hover { border-color: var(--border-strong); transform: translateY(-4px); }
.step .num {
  font-family: var(--font-mono); font-size: 42px; font-weight: 800; line-height: 1;
  background: var(--grad); -webkit-background-clip: text; background-clip: text; color: transparent; opacity: .5; margin-bottom: 18px;
}
.step h4 { font-size: 18px; margin-bottom: 8px; }
.step p { color: var(--txt-dim); font-size: 14px; }

/* ---------- AI Workflow banner ---------- */
.ai-banner {
  display: flex; align-items: center; gap: 30px;
  background: linear-gradient(135deg, rgba(79,124,255,.14), rgba(166,120,255,.14));
  border: 1px solid var(--border-strong);
  border-radius: var(--radius-lg);
  padding: 40px;
  overflow: hidden;
  position: relative;
}
.ai-banner::after {
  content: ""; position: absolute; right: -80px; top: -80px; width: 240px; height: 240px; border-radius: 50%;
  background: radial-gradient(circle, rgba(34,211,238,.25), transparent 70%);
}
.ai-banner .txt { flex: 1; position: relative; z-index: 1; }
.ai-banner .txt h3 { font-size: 26px; margin-bottom: 10px; }
.ai-banner .txt p { color: var(--txt-dim); }
.ai-banner .ai-term {
  flex: 1; font-family: var(--font-mono); font-size: 15px;
  background: rgba(5,6,15,.6); border: 1px solid var(--border); border-radius: var(--radius);
  padding: 22px; line-height: 2; position: relative; z-index: 1;
}
.ai-banner .ai-term .arrow { color: var(--accent-3); }

/* ---------- Pricing ---------- */
.pricing-grid { display: grid; grid-template-columns: repeat(4, 1fr); gap: 20px; align-items: stretch; }
.plan {
  display: flex; flex-direction: column;
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--radius-lg);
  padding: 30px 26px;
  position: relative;
  transition: all .3s;
}
.plan:hover { transform: translateY(-6px); border-color: var(--border-strong); box-shadow: var(--shadow); }
.plan.hot {
  background: linear-gradient(180deg, rgba(79,124,255,.16), rgba(166,120,255,.1));
  border-color: var(--accent);
  box-shadow: var(--glow);
}
.plan .pname { font-size: 18px; font-weight: 700; margin-bottom: 6px; }
.plan .pfor { font-size: 13px; color: var(--txt-faint); margin-bottom: 20px; }
.plan .price { font-size: 34px; font-weight: 800; margin-bottom: 4px; }
.plan .price small { font-size: 15px; font-weight: 500; color: var(--txt-faint); }
.plan .billed { font-size: 13px; color: var(--txt-faint); margin-bottom: 22px; }
.plan ul { flex: 1; margin-bottom: 24px; }
.plan li { font-size: 14px; color: var(--txt-dim); padding: 6px 0; display: flex; gap: 10px; align-items: flex-start; }
.plan li i { color: var(--accent-3); font-size: 14px; margin-top: 4px; }
.plan li.disabled { opacity: .4; }
.plan .btn { width: 100%; justify-content: center; }
.plan-badge {
  position: absolute; top: -12px; right: 18px;
  background: var(--grad); color: #fff; font-size: 12px; font-weight: 700;
  padding: 4px 12px; border-radius: 100px; letter-spacing: .5px;
}

/* ---------- Testimonials / Social proof ---------- */
.review-grid { display: grid; grid-template-columns: repeat(3, 1fr); gap: 20px; }
.review {
  background: var(--surface); border: 1px solid var(--border); border-radius: var(--radius-lg); padding: 26px;
  display: flex; flex-direction: column;
}
.review .stars { color: #fbbf24; margin-bottom: 14px; font-size: 14px; }
.review p { color: var(--txt-dim); font-size: 15px; flex: 1; }
.review .who { display: flex; align-items: center; gap: 12px; margin-top: 18px; }
.review .avatar { width: 40px; height: 40px; border-radius: 50%; background: var(--grad-soft); border: 1px solid var(--border-strong); display: grid; place-items: center; font-size: 16px; }
.review .who b { display: block; font-size: 14px; }
.review .who span { font-size: 12px; color: var(--txt-faint); }

/* ---------- FAQ ---------- */
.faq { max-width: 860px; margin: 0 auto; }
.faq-item { border: 1px solid var(--border); border-radius: var(--radius); margin-bottom: 12px; overflow: hidden; background: var(--surface); transition: border-color .3s; }
.faq-item.open { border-color: var(--accent); }
.faq-q {
  width: 100%; display: flex; justify-content: space-between; align-items: center; gap: 16px;
  background: none; border: none; cursor: pointer;
  padding: 20px 24px; font-size: 16px; font-weight: 600; color: var(--txt); text-align: left;
  font-family: var(--font-sans);
}
.faq-q i { transition: transform .3s; color: var(--accent); }
.faq-item.open .faq-q i { transform: rotate(180deg); }
.faq-a { max-height: 0; overflow: hidden; transition: max-height .4s ease; }
.faq-a p { padding: 0 24px 20px; color: var(--txt-dim); font-size: 15px; }

/* ---------- CTA ---------- */
.cta {
  text-align: center;
  padding: 90px 0;
  position: relative;
  overflow: hidden;
}
.cta h2 { font-size: clamp(30px, 4vw, 46px); font-weight: 800; margin-bottom: 18px; }
.cta p { color: var(--txt-dim); max-width: 600px; margin: 0 auto 36px; font-size: 17px; }
.cta-actions { display: flex; gap: 16px; justify-content: center; flex-wrap: wrap; }

/* ---------- Footer ---------- */
.footer { border-top: 1px solid var(--border); background: var(--bg-1); padding: 60px 0 0; }
.footer-top { display: grid; grid-template-columns: 2fr 1fr 1fr 1fr; gap: 40px; padding-bottom: 40px; }
.footer-brand p { color: var(--txt-faint); font-size: 14px; margin-top: 16px; max-width: 320px; }
.footer h5 { font-size: 14px; letter-spacing: 1px; text-transform: uppercase; color: var(--txt-dim); margin-bottom: 18px; }
.footer-col a { display: block; color: var(--txt-faint); font-size: 14px; padding: 5px 0; transition: color .2s; }
.footer-col a:hover { color: var(--accent-3); }
.footer-soc { display: flex; gap: 12px; margin-top: 16px; }
.footer-soc a { width: 38px; height: 38px; display: grid; place-items: center; border: 1px solid var(--border); border-radius: var(--radius); color: var(--txt-dim); transition: all .2s; }
.footer-soc a:hover { color: #fff; border-color: var(--accent); background: var(--grad-soft); }
.footer-bottom { border-top: 1px solid var(--border); padding: 20px 0; }
.footer-bottom .container { display: flex; justify-content: space-between; align-items: center; flex-wrap: wrap; gap: 12px; }
.footer-bottom p { color: var(--txt-faint); font-size: 13px; }
.footer-bottom .links a { color: var(--txt-faint); font-size: 13px; margin-left: 18px; }
.footer-bottom .links a:hover { color: var(--accent-3); }

/* ---------- Reveal animation ---------- */
.reveal { opacity: 0; transform: translateY(30px); transition: opacity .7s ease, transform .7s ease; }
.reveal.in-view { opacity: 1; transform: none; }

/* ---------- Back to top ---------- */
#toTop {
  position: fixed; bottom: 28px; right: 28px; z-index: 90;
  width: 46px; height: 46px; border-radius: 50%;
  border: 1px solid var(--border-strong); background: var(--bg-2); color: var(--txt);
  display: grid; place-items: center; cursor: pointer; font-size: 18px;
  opacity: 0; visibility: hidden; transform: translateY(12px); transition: all .3s;
}
#toTop.show { opacity: 1; visibility: visible; transform: none; }
#toTop:hover { background: var(--grad); border-color: transparent; }

/* ---------- Responsive ---------- */
@media (max-width: 1080px) {
  .feature-grid, .review-grid { grid-template-columns: repeat(2, 1fr); }
  .pricing-grid { grid-template-columns: repeat(2, 1fr); }
  .steps { grid-template-columns: repeat(2, 1fr); }
}
@media (max-width: 900px) {
  .nav-links {
    position: fixed; top: 68px; right: 20px; left: 20px;
    flex-direction: column; align-items: stretch;
    background: var(--bg-2); border: 1px solid var(--border);
    border-radius: var(--radius-lg); padding: 12px;
    opacity: 0; visibility: hidden; transform: translateY(-10px); transition: all .3s;
  }
  .nav-links.open { opacity: 1; visibility: visible; transform: none; }
  .nav-links a { padding: 12px 14px; }
  .nav-toggle { display: grid; place-items: center; }
  .scenario-grid, .ai-banner { grid-template-columns: 1fr; }
  .footer-top { grid-template-columns: 1fr 1fr; }
}
@media (max-width: 620px) {
  .section { padding: 64px 0; }
  .hero { padding: 140px 0 70px; }
  .feature-grid, .review-grid, .pricing-grid, .steps { grid-template-columns: 1fr; }
  .hero-stats { gap: 30px; }
  .footer-top { grid-template-columns: 1fr; }
  .footer-bottom .container { flex-direction: column; text-align: center; }
}