:root {
  --paper: #f4efe6;
  --paper-deep: #e8e0d2;
  --ink: #172b38;
  --muted: #66727a;
  --coral: #f16f48;
  --blue: #4e86f7;
  --aqua: #bce9de;
  --line: rgba(23, 43, 56, 0.15);
  --radius: 28px;
}

* { box-sizing: border-box; }
html { scroll-behavior: smooth; }
body {
  margin: 0;
  color: var(--ink);
  background: var(--paper);
  font-family: "PingFang SC", "Microsoft YaHei", "Noto Sans CJK SC", system-ui, sans-serif;
  -webkit-font-smoothing: antialiased;
}
a { color: inherit; text-decoration: none; }
button, input { font: inherit; }
button, a { -webkit-tap-highlight-color: transparent; }
.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; }
.skip-link { position: fixed; left: 18px; top: -80px; z-index: 100; background: var(--ink); color: white; padding: 12px 18px; border-radius: 99px; transition: top .2s; }
.skip-link:focus { top: 18px; }

.site-header {
  position: fixed;
  z-index: 50;
  top: 16px;
  left: 50%;
  transform: translateX(-50%);
  width: min(1180px, calc(100% - 32px));
  min-height: 70px;
  padding: 10px 12px 10px 18px;
  display: flex;
  align-items: center;
  justify-content: space-between;
  border: 1px solid rgba(255, 255, 255, .7);
  border-radius: 18px;
  background: rgba(244, 239, 230, .82);
  backdrop-filter: blur(18px);
  box-shadow: 0 12px 35px rgba(23, 43, 56, .08);
}
.brand { display: inline-flex; align-items: center; gap: 11px; }
.brand-mark { display: grid; place-items: center; width: 40px; height: 40px; background: var(--ink); color: white; border-radius: 12px; font-family: serif; font-size: 22px; font-weight: 700; }
.brand-copy { display: flex; flex-direction: column; line-height: 1; }
.brand-copy strong { font-size: 17px; letter-spacing: .03em; }
.brand-copy small { margin-top: 5px; color: var(--muted); font-size: 9px; letter-spacing: .2em; }
.site-nav { display: flex; align-items: center; gap: 30px; font-size: 14px; font-weight: 600; }
.site-nav > a:not(.nav-cta) { position: relative; }
.site-nav > a:not(.nav-cta)::after { content: ""; position: absolute; left: 0; right: 100%; bottom: -7px; height: 2px; background: var(--coral); transition: right .2s; }
.site-nav > a:not(.nav-cta):hover::after, .site-nav > a:not(.nav-cta):focus-visible::after { right: 0; }
.nav-cta { padding: 14px 19px; background: var(--ink); color: white; border-radius: 12px; }
.menu-button { display: none; width: 44px; height: 44px; border: 0; border-radius: 12px; background: var(--ink); }
.menu-button span:not(.sr-only) { display: block; width: 19px; height: 2px; margin: 5px auto; background: white; }

.hero {
  position: relative;
  min-height: 840px;
  overflow: hidden;
  padding: 166px max(5vw, calc((100vw - 1180px) / 2)) 90px;
  display: grid;
  grid-template-columns: .95fr 1.05fr;
  align-items: center;
  gap: clamp(36px, 6vw, 100px);
  background-image: linear-gradient(rgba(23,43,56,.035) 1px, transparent 1px), linear-gradient(90deg, rgba(23,43,56,.035) 1px, transparent 1px);
  background-size: 36px 36px;
}
.hero::after { content: "LEXCHAT"; position: absolute; left: -8px; bottom: -62px; color: rgba(23,43,56,.035); font: 900 clamp(110px, 19vw, 290px)/1 Arial, sans-serif; letter-spacing: -.09em; pointer-events: none; }
.hero-orb { position: absolute; border-radius: 50%; filter: blur(1px); pointer-events: none; }
.orb-one { width: 360px; height: 360px; right: -160px; top: 130px; background: rgba(188,233,222,.68); }
.orb-two { width: 170px; height: 170px; left: 42%; bottom: 80px; background: rgba(241,111,72,.14); }
.hero-copy { position: relative; z-index: 2; }
.eyebrow, .section-kicker { margin: 0 0 24px; color: var(--muted); font-size: 12px; font-weight: 800; letter-spacing: .15em; text-transform: uppercase; }
.eyebrow { display: inline-flex; align-items: center; gap: 10px; }
.eyebrow span { width: 24px; height: 2px; background: var(--coral); }
.hero h1 { max-width: 600px; margin: 0; font-size: clamp(54px, 6.4vw, 92px); line-height: .98; letter-spacing: -.07em; font-weight: 800; }
.hero h1 em { display: block; color: var(--coral); font-family: "Songti SC", "STSong", serif; font-weight: 500; }
.hero-lead { max-width: 545px; margin: 30px 0 0; color: #46555d; font-size: 18px; line-height: 1.9; }
.hero-actions { margin-top: 36px; display: flex; align-items: center; gap: 26px; }
.button { display: inline-flex; min-height: 54px; align-items: center; justify-content: center; gap: 22px; padding: 0 23px; border-radius: 14px; font-size: 15px; font-weight: 700; transition: transform .2s, box-shadow .2s; }
.button:hover, .button:focus-visible { transform: translateY(-2px); }
.button-primary { background: var(--ink); color: white; box-shadow: 0 12px 26px rgba(23,43,56,.18); }
.button-primary span, .button-light span { font-size: 21px; }
.text-link { border-bottom: 1px solid currentColor; padding: 8px 0; font-size: 14px; font-weight: 700; }
.trust-line { display: flex; gap: 16px; margin-top: 42px; color: var(--muted); font-size: 12px; }
.trust-line span { display: inline-flex; align-items: center; gap: 7px; }
.trust-line span::before { content: "✓"; display: grid; place-items: center; width: 18px; height: 18px; color: var(--ink); background: var(--aqua); border-radius: 50%; font-size: 11px; font-weight: 900; }

.chat-shell { position: relative; z-index: 3; width: min(100%, 580px); margin-left: auto; overflow: hidden; border: 1px solid rgba(23,43,56,.12); border-radius: 32px; background: rgba(255,255,255,.88); box-shadow: 0 38px 80px rgba(23,43,56,.18); transform: rotate(1.2deg); }
.chat-topbar { padding: 19px 21px; display: flex; justify-content: space-between; align-items: center; border-bottom: 1px solid var(--line); background: #fff; }
.assistant-identity { display: flex; align-items: center; gap: 11px; }
.assistant-avatar, .mini-avatar { display: grid; place-items: center; flex: 0 0 auto; color: white; background: var(--ink); border-radius: 11px; font-family: serif; font-weight: 700; }
.assistant-avatar { width: 38px; height: 38px; }
.assistant-identity div { display: flex; flex-direction: column; gap: 5px; }
.assistant-identity strong { font-size: 14px; }
.assistant-identity small { color: var(--muted); font-size: 10px; }
.assistant-identity i { display: inline-block; width: 6px; height: 6px; margin-right: 4px; border-radius: 50%; background: #4abc7d; }
.safe-badge { padding: 7px 10px; color: #3b5a51; background: #e4f4ef; border-radius: 99px; font-size: 10px; font-weight: 700; }
.chat-body { height: 368px; overflow-y: auto; padding: 24px 21px 12px; background: #faf9f6; }
.message { max-width: 88%; font-size: 13px; line-height: 1.65; }
.message-user { width: fit-content; margin-left: auto; padding: 13px 15px; color: white; background: var(--ink); border-radius: 16px 16px 4px 16px; }
.message-ai { display: flex; align-items: flex-start; gap: 10px; margin-top: 18px; }
.mini-avatar { width: 27px; height: 27px; border-radius: 8px; font-size: 12px; }
.message-ai > div { padding: 14px 15px; border: 1px solid var(--line); border-radius: 4px 16px 16px 16px; background: white; }
.message-ai p { margin: 0; }
.message-ai ol { margin: 12px 0; padding: 0; list-style: none; display: grid; gap: 8px; counter-reset: item; }
.message-ai li { position: relative; padding-left: 25px; display: flex; flex-direction: column; counter-increment: item; }
.message-ai li::before { content: counter(item); position: absolute; left: 0; top: 1px; display: grid; place-items: center; width: 17px; height: 17px; border-radius: 50%; color: white; background: var(--coral); font-size: 9px; font-weight: 800; }
.message-ai li span { color: var(--muted); font-size: 11px; }
.message-ai .chat-note { color: #3e6c61; font-size: 11px; font-weight: 700; }
.quick-questions { display: flex; gap: 7px; overflow-x: auto; padding: 12px 18px 8px; background: white; scrollbar-width: none; }
.quick-questions::-webkit-scrollbar { display: none; }
.quick-questions button { flex: 0 0 auto; padding: 8px 10px; border: 1px solid var(--line); border-radius: 99px; color: var(--ink); background: white; cursor: pointer; font-size: 10px; }
.quick-questions button:hover { border-color: var(--coral); }
.chat-input { margin: 6px 18px 10px; padding: 6px 6px 6px 14px; display: flex; border: 1px solid var(--line); border-radius: 14px; background: white; }
.chat-input input { min-width: 0; flex: 1; border: 0; outline: 0; color: var(--ink); background: transparent; font-size: 12px; }
.chat-input button { width: 36px; height: 36px; border: 0; border-radius: 10px; color: white; background: var(--coral); cursor: pointer; font-size: 18px; }
.demo-disclaimer { margin: 0; padding: 0 18px 14px; color: #92999d; background: white; font-size: 9px; text-align: center; }

.signal-strip { position: relative; z-index: 4; padding: 28px max(5vw, calc((100vw - 1180px) / 2)); display: flex; align-items: center; justify-content: space-between; gap: 40px; color: white; background: var(--ink); }
.signal-strip p { margin: 0; color: var(--aqua); font-family: serif; font-size: 16px; }
.signal-strip div { display: flex; flex-wrap: wrap; gap: 34px; font-size: 12px; }
.signal-strip span { display: flex; align-items: center; gap: 8px; }
.signal-strip b { color: var(--coral); font-size: 10px; }

.section { padding: 118px max(5vw, calc((100vw - 1180px) / 2)); }
.section-heading { display: grid; grid-template-columns: 1.2fr .8fr; align-items: end; gap: 80px; margin-bottom: 54px; }
.section-kicker { color: var(--coral); margin-bottom: 18px; }
.section h2 { margin: 0; font-size: clamp(38px, 4.4vw, 62px); line-height: 1.12; letter-spacing: -.055em; }
.section-heading > p { max-width: 440px; margin: 0 0 7px; color: var(--muted); font-size: 15px; line-height: 1.9; }
.capabilities { background: #fffdf9; }
.capability-grid { display: grid; grid-template-columns: repeat(4, 1fr); gap: 14px; }
.capability-card { min-height: 355px; padding: 24px; display: flex; flex-direction: column; border-radius: 24px; transition: transform .25s; }
.capability-card:hover { transform: translateY(-7px); }
.card-dark { color: white; background: var(--ink); }
.card-coral { color: #3e261f; background: var(--coral); }
.card-cream { background: #e9e1d5; }
.card-blue { color: white; background: var(--blue); }
.card-number { align-self: flex-end; color: currentColor; opacity: .55; font: 700 11px/1 monospace; }
.card-symbol { position: relative; width: 94px; height: 94px; margin: 36px 0 auto; }
.balance-symbol::before { content: ""; position: absolute; left: 45px; top: 6px; width: 3px; height: 70px; background: var(--aqua); }
.balance-symbol::after { content: ""; position: absolute; left: 17px; top: 24px; width: 58px; height: 3px; background: var(--aqua); transform: rotate(-7deg); }
.balance-symbol i:nth-child(1), .balance-symbol i:nth-child(2) { position: absolute; top: 37px; width: 28px; height: 18px; border: 3px solid var(--aqua); border-top: 0; border-radius: 0 0 22px 22px; }
.balance-symbol i:nth-child(1) { left: 7px; }.balance-symbol i:nth-child(2) { right: 1px; }
.balance-symbol i:nth-child(3) { position: absolute; left: 31px; bottom: 8px; width: 32px; height: 3px; background: var(--aqua); }
.scan-symbol { border: 2px solid rgba(62,38,31,.25); border-radius: 13px; }
.scan-symbol::after { content: ""; position: absolute; left: 15px; right: 15px; top: 48px; height: 3px; background: #3e261f; box-shadow: 0 0 12px white; }
.scan-symbol i { position: absolute; left: 18px; height: 3px; background: rgba(62,38,31,.7); }
.scan-symbol i:nth-child(1) { top: 20px; width: 39px; }.scan-symbol i:nth-child(2) { top: 31px; width: 56px; }.scan-symbol i:nth-child(3) { top: 66px; width: 44px; }
.radar-symbol { border: 3px solid var(--ink); border-radius: 50%; }
.radar-symbol::before, .radar-symbol::after { content: ""; position: absolute; border: 2px solid var(--ink); border-radius: 50%; }
.radar-symbol::before { inset: 17px; }.radar-symbol::after { inset: 34px; background: var(--coral); border: 0; }
.radar-symbol i:nth-child(1) { position: absolute; width: 36px; height: 2px; left: 45px; top: 45px; background: var(--ink); transform-origin: left; transform: rotate(-49deg); }
.route-symbol i { position: absolute; border-radius: 50%; background: white; }
.route-symbol i:nth-child(1) { width: 15px; height: 15px; left: 3px; bottom: 11px; }
.route-symbol i:nth-child(2) { width: 11px; height: 11px; left: 42px; top: 37px; }
.route-symbol i:nth-child(3) { width: 19px; height: 19px; right: 2px; top: 2px; background: var(--aqua); }
.route-symbol::before { content: ""; position: absolute; left: 12px; bottom: 25px; width: 76px; height: 48px; border-top: 3px dashed white; transform: rotate(-31deg); }
.capability-card h3 { margin: 24px 0 8px; font-size: 23px; }
.capability-card p { margin: 0; color: currentColor; opacity: .73; font-size: 13px; line-height: 1.75; }

.scenarios { display: grid; grid-template-columns: .72fr 1.28fr; gap: 80px; background: var(--paper); }
.scenarios-intro { position: sticky; top: 125px; align-self: start; }
.scenarios-intro > p:last-child { max-width: 340px; margin-top: 24px; color: var(--muted); line-height: 1.8; }
.scenario-browser { min-width: 0; }
.scenario-tabs { display: flex; gap: 8px; overflow-x: auto; margin-bottom: 14px; padding-bottom: 4px; scrollbar-width: none; }
.scenario-tabs button { flex: 0 0 auto; padding: 11px 14px; border: 1px solid var(--line); border-radius: 99px; color: var(--muted); background: transparent; cursor: pointer; font-size: 12px; }
.scenario-tabs button[aria-selected="true"] { color: white; background: var(--ink); border-color: var(--ink); }
.scenario-panel { min-height: 470px; padding: 38px; display: grid; grid-template-columns: 100px 1fr; gap: 28px; color: white; background: var(--ink); border-radius: 28px; box-shadow: 18px 18px 0 var(--aqua); }
.panel-index { color: var(--coral); font: 800 64px/1 Arial, sans-serif; letter-spacing: -.09em; opacity: .9; }
.panel-tag { display: inline-flex; padding: 7px 10px; color: var(--aqua); border: 1px solid rgba(188,233,222,.35); border-radius: 99px; font-size: 10px; font-weight: 700; }
.scenario-panel h3 { margin: 30px 0 15px; font-size: clamp(28px, 3vw, 40px); line-height: 1.24; letter-spacing: -.04em; }
.scenario-panel p { margin: 0; color: #b8c1c5; font-size: 14px; line-height: 1.9; }
.scenario-panel ul { margin: 30px 0 0; padding: 0; display: grid; gap: 13px; list-style: none; }
.scenario-panel li { position: relative; padding: 13px 14px 13px 42px; border: 1px solid rgba(255,255,255,.1); border-radius: 12px; background: rgba(255,255,255,.045); font-size: 12px; }
.scenario-panel li::before { content: "✓"; position: absolute; left: 15px; color: var(--coral); font-weight: 900; }

.method { background: #fffdf9; }
.method-card { padding: clamp(34px, 6vw, 76px); display: grid; grid-template-columns: .9fr 1.1fr; gap: 90px; border-radius: 34px; background: #e8e0d2; }
.method-steps { margin: 0; padding: 0; display: grid; gap: 0; list-style: none; }
.method-steps li { position: relative; padding: 0 0 33px; display: grid; grid-template-columns: 48px 1fr; gap: 18px; }
.method-steps li:not(:last-child)::before { content: ""; position: absolute; left: 23px; top: 47px; bottom: 0; border-left: 1px dashed rgba(23,43,56,.34); }
.method-steps span { position: relative; z-index: 1; display: grid; place-items: center; width: 48px; height: 48px; color: white; background: var(--ink); border-radius: 50%; font: 700 13px/1 monospace; }
.method-steps h3 { margin: 2px 0 5px; font-size: 19px; }
.method-steps p { margin: 0; color: var(--muted); font-size: 13px; line-height: 1.7; }

.final-cta { min-height: 370px; padding: 75px max(5vw, calc((100vw - 1180px) / 2)); display: flex; align-items: center; justify-content: space-between; gap: 50px; color: white; background: var(--coral); }
.cta-mark { display: grid; place-items: center; width: 54px; height: 54px; margin-bottom: 25px; color: var(--coral); background: white; border-radius: 16px; font-family: serif; font-size: 26px; font-weight: 700; }
.final-cta p { margin: 0 0 10px; font-size: 13px; font-weight: 700; }
.final-cta h2 { max-width: 750px; margin: 0; font-size: clamp(33px, 4.2vw, 60px); line-height: 1.15; letter-spacing: -.055em; }
.button-light { flex: 0 0 auto; color: var(--ink); background: white; }

footer { color: white; background: var(--ink); }
.footer-main { padding: 60px max(5vw, calc((100vw - 1180px) / 2)); display: grid; grid-template-columns: 1fr 1fr auto; align-items: center; gap: 40px; }
.footer-brand .brand-mark { background: var(--coral); }
.footer-brand .brand-copy small { color: #98a5ab; }
.footer-main > p { margin: 0; color: #98a5ab; font-size: 13px; }
.footer-main nav { display: flex; gap: 22px; font-size: 12px; }
.footer-legal { min-height: 56px; padding: 15px max(5vw, calc((100vw - 1180px) / 2)); display: flex; align-items: center; justify-content: space-between; gap: 20px; border-top: 1px solid rgba(255,255,255,.1); color: #92a0a6; font-size: 11px; }
.footer-legal a:hover, .footer-legal a:focus-visible { color: white; text-decoration: underline; }

@media (max-width: 980px) {
  .menu-button { display: block; }
  .site-nav { position: absolute; top: 78px; left: 0; right: 0; padding: 18px; display: none; align-items: stretch; flex-direction: column; gap: 4px; border: 1px solid rgba(255,255,255,.7); border-radius: 18px; background: rgba(244,239,230,.98); box-shadow: 0 18px 40px rgba(23,43,56,.15); }
  .site-nav.open { display: flex; }
  .site-nav a { padding: 14px; border-radius: 10px; }
  .hero { grid-template-columns: 1fr; padding-top: 150px; }
  .hero-copy { max-width: 680px; }
  .chat-shell { width: min(100%, 660px); margin: 0 auto; transform: none; }
  .capability-grid { grid-template-columns: repeat(2, 1fr); }
  .scenarios { grid-template-columns: 1fr; gap: 45px; }
  .scenarios-intro { position: static; }
  .method-card { grid-template-columns: 1fr; gap: 55px; }
  .footer-main { grid-template-columns: 1fr 1fr; }
  .footer-main nav { grid-column: 1 / -1; }
}

@media (max-width: 680px) {
  .site-header { top: 10px; width: calc(100% - 20px); }
  .hero { min-height: 0; padding: 130px 20px 65px; gap: 55px; }
  .hero h1 { font-size: clamp(49px, 15vw, 66px); }
  .hero-lead { font-size: 15px; }
  .hero-actions { align-items: stretch; flex-direction: column; gap: 10px; }
  .button { width: 100%; }
  .text-link { align-self: flex-start; }
  .trust-line { flex-wrap: wrap; }
  .chat-shell { border-radius: 23px; }
  .chat-body { height: 400px; }
  .signal-strip { padding: 26px 20px; align-items: flex-start; flex-direction: column; }
  .signal-strip div { display: grid; grid-template-columns: 1fr 1fr; gap: 18px; }
  .section { padding: 78px 20px; }
  .section-heading { grid-template-columns: 1fr; gap: 24px; }
  .section h2 { font-size: 40px; }
  .capability-grid { grid-template-columns: 1fr; }
  .capability-card { min-height: 315px; }
  .scenario-panel { min-height: 0; padding: 27px 22px 31px; grid-template-columns: 1fr; box-shadow: 9px 10px 0 var(--aqua); }
  .panel-index { font-size: 48px; }
  .scenario-panel h3 { margin-top: 24px; }
  .method-card { padding: 33px 22px; border-radius: 24px; }
  .final-cta { padding: 65px 20px; align-items: stretch; flex-direction: column; }
  .footer-main { padding: 50px 20px; grid-template-columns: 1fr; }
  .footer-main nav { grid-column: auto; flex-wrap: wrap; }
  .footer-legal { padding: 18px 20px; align-items: flex-start; flex-direction: column; }
}

@media (prefers-reduced-motion: reduce) {
  html { scroll-behavior: auto; }
  *, *::before, *::after { transition-duration: .01ms !important; animation-duration: .01ms !important; animation-iteration-count: 1 !important; }
}