:root {
  --primary: #2563eb;
  --primary-dark: #1d4ed8;
  --accent: #f97316;
  --bg: #ffffff;
  --bg-alt: #f5f7fb;
  --text: #0f172a;
  --muted: #64748b;
  --border: #e2e8f0;
  --radius: 16px;
  --shadow: 0 10px 40px rgba(15, 23, 42, 0.08);
}

* { box-sizing: border-box; margin: 0; padding: 0; }
html { scroll-behavior: smooth; }
body {
  font-family: -apple-system, BlinkMacSystemFont, "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei", "Helvetica Neue", Arial, sans-serif;
  color: var(--text);
  background: var(--bg);
  line-height: 1.6;
  -webkit-font-smoothing: antialiased;
}
a { color: inherit; text-decoration: none; }
button { font: inherit; cursor: pointer; border: none; background: none; color: inherit; }
ul { list-style: none; }

.container { width: min(1180px, 100% - 32px); margin: 0 auto; }
.container.narrow { max-width: 820px; }
.center-text { text-align: center; }

/* 标签 / 标题 */
.tag {
  display: inline-block;
  padding: 4px 12px;
  border-radius: 999px;
  background: rgba(37, 99, 235, 0.08);
  color: var(--primary);
  font-size: 13px;
  font-weight: 600;
  margin-bottom: 14px;
}
.tag.small { font-size: 12px; }
h1 { font-size: clamp(36px, 5vw, 60px); line-height: 1.15; font-weight: 800; letter-spacing: -0.02em; }
h2 { font-size: clamp(26px, 3.4vw, 38px); font-weight: 800; letter-spacing: -0.01em; }
h3 { font-size: 20px; font-weight: 700; }
.grad {
  background: linear-gradient(90deg, var(--primary), #7c3aed 60%, var(--accent));
  -webkit-background-clip: text;
  background-clip: text;
  color: transparent;
}
.lead { color: var(--muted); font-size: 17px; }

/* 按钮 */
.btn {
  display: inline-flex; align-items: center; justify-content: center;
  padding: 10px 20px; border-radius: 10px; font-weight: 600; font-size: 15px;
  transition: all .2s ease; white-space: nowrap;
}
.btn-lg { padding: 14px 28px; font-size: 16px; border-radius: 12px; }
.btn-primary { background: var(--primary); color: #fff; box-shadow: 0 6px 18px rgba(37, 99, 235, .3); }
.btn-primary:hover { background: var(--primary-dark); transform: translateY(-1px); }
.btn-outline { border: 1.5px solid var(--border); color: var(--text); background: #fff; }
.btn-outline:hover { border-color: var(--primary); color: var(--primary); }
.btn-ghost { color: var(--muted); }
.btn-ghost:hover { color: var(--text); }
.btn-light { background: #fff; color: var(--primary); }
.btn-light:hover { transform: translateY(-1px); }
.btn.block { width: 100%; margin-top: 20px; }
.link { color: var(--primary); font-weight: 600; font-size: 14px; }
.link:hover { text-decoration: underline; }

/* 导航 */
.nav {
  position: sticky; top: 0; z-index: 50;
  background: rgba(255, 255, 255, .85);
  backdrop-filter: blur(12px);
  border-bottom: 1px solid var(--border);
}
.nav-inner { display: flex; align-items: center; justify-content: space-between; height: 68px; gap: 24px; }
.brand { display: flex; align-items: center; gap: 10px; font-weight: 800; font-size: 18px; }
.brand-logo {
  width: 34px; height: 34px; border-radius: 9px; display: grid; place-items: center;
  background: linear-gradient(135deg, var(--primary), #7c3aed); color: #fff; font-size: 17px;
}
.nav-links { display: flex; gap: 28px; font-size: 15px; color: #334155; }
.nav-links a:hover { color: var(--primary); }
.nav-actions { display: flex; align-items: center; gap: 8px; }
.nav-toggle { display: none; font-size: 22px; padding: 4px 8px; }

/* Hero */
.hero { position: relative; padding: 90px 0 70px; overflow: hidden; }
.hero-bg {
  position: absolute; inset: 0; z-index: -1;
  background:
    radial-gradient(600px 400px at 15% 10%, rgba(37, 99, 235, .14), transparent 60%),
    radial-gradient(500px 350px at 90% 30%, rgba(249, 115, 22, .12), transparent 60%),
    radial-gradient(500px 400px at 70% 90%, rgba(124, 58, 237, .10), transparent 60%);
}
.hero-inner { display: grid; grid-template-columns: 1.1fr 1fr; gap: 48px; align-items: center; }
.hero-copy .lead { margin: 22px 0 30px; max-width: 520px; }
.hero-cta { display: flex; gap: 14px; flex-wrap: wrap; }
.hero-stats { display: flex; gap: 40px; margin-top: 44px; }
.hero-stats div { display: flex; flex-direction: column; }
.hero-stats strong { font-size: 26px; font-weight: 800; }
.hero-stats span { color: var(--muted); font-size: 14px; }

.hero-visual { position: relative; min-height: 420px; }
.mock-card { background: #fff; border-radius: var(--radius); box-shadow: var(--shadow); border: 1px solid var(--border); }
.mock-main { padding: 18px; width: 100%; max-width: 480px; margin-left: auto; }
.mock-head { display: flex; align-items: center; gap: 6px; margin-bottom: 14px; }
.mock-head .dot { width: 10px; height: 10px; border-radius: 50%; background: #e2e8f0; }
.mock-head .dot:nth-child(1) { background: #fca5a5; }
.mock-head .dot:nth-child(2) { background: #fde68a; }
.mock-head .dot:nth-child(3) { background: #86efac; }
.mock-head em { margin-left: auto; font-style: normal; font-size: 13px; color: var(--muted); }
.mock-chat { display: flex; flex-direction: column; gap: 10px; }
.bubble { max-width: 88%; padding: 10px 14px; border-radius: 14px; font-size: 13.5px; line-height: 1.55; }
.bubble.user { align-self: flex-end; background: var(--primary); color: #fff; border-bottom-right-radius: 4px; }
.bubble.ai { align-self: flex-start; background: var(--bg-alt); border-bottom-left-radius: 4px; }
.bubble.typing { display: flex; gap: 5px; padding: 14px 16px; }
.bubble.typing span { width: 7px; height: 7px; border-radius: 50%; background: #94a3b8; animation: blink 1.2s infinite; }
.bubble.typing span:nth-child(2) { animation-delay: .2s; }
.bubble.typing span:nth-child(3) { animation-delay: .4s; }
@keyframes blink { 0%, 80%, 100% { opacity: .3; } 40% { opacity: 1; } }

.mock-float { position: absolute; padding: 14px 18px; animation: float 5s ease-in-out infinite; }
.mock-price { left: -10px; bottom: 40px; display: flex; flex-direction: column; }
.mock-price small { color: var(--muted); font-size: 12px; }
.mock-price strong { font-size: 22px; }
.mock-price .up { color: #16a34a; font-size: 12px; }
.mock-avatar { right: -10px; top: -20px; display: flex; align-items: center; gap: 12px; animation-delay: 1.5s; }
.mock-avatar small { display: block; color: var(--muted); font-size: 12px; }
.avatar {
  width: 44px; height: 44px; border-radius: 50%;
  background: linear-gradient(135deg, #fbbf24, #f97316 60%, #ec4899);
  position: relative;
}
.avatar::after { content: ""; position: absolute; right: 1px; bottom: 1px; width: 11px; height: 11px; border-radius: 50%; background: #22c55e; border: 2px solid #fff; }
@keyframes float { 0%, 100% { transform: translateY(0); } 50% { transform: translateY(-10px); } }

/* Default introduction, linked to the established eight-module workbench. */
body{min-width:320px}
.container{width:min(1440px,100% - 96px)}
.nav-inner{height:80px;gap:24px}
.brand{flex-shrink:0;gap:12px}
.brand-name{font-size:21px;letter-spacing:-.6px}
.brand-ai{color:#315efb;margin-left:3px;font-style:italic;font-weight:900}
.brand-logo{width:40px;height:40px;font-size:21px;border-radius:11px}
.nav-links{gap:22px;font-size:14px;white-space:nowrap}
.nav-links a{padding:12px 0;transition:color .15s}
.nav-actions{flex-shrink:0}
.btn{gap:12px;touch-action:manipulation}
.nav-actions .btn{padding:12px 19px}
.hero{isolation:isolate;padding:110px 0 95px;min-height:calc(100svh - 145px);display:flex;align-items:center}
.hero-bg{background:radial-gradient(700px 500px at 13% 4%,rgba(37,99,235,.13),transparent 65%),radial-gradient(600px 460px at 95% 25%,rgba(249,115,22,.085),transparent 65%),radial-gradient(640px 420px at 76% 97%,rgba(124,58,237,.1),transparent 62%)}
.hero-inner{grid-template-columns:1.05fr 1fr;gap:96px;align-items:center}
.tag{font-size:14px;padding:6px 14px;margin-bottom:18px}
h1{font-size:clamp(46px,4.6vw,72px);line-height:1.2;letter-spacing:-2px}
.hero-copy .lead{font-size:18px;line-height:1.85;margin:26px 0 34px;max-width:600px}
.btn-lg{padding:16px 28px;font-size:17px}
.hero-stats{gap:42px;margin-top:48px}
.hero-stats strong{font-size:32px;line-height:1.3;letter-spacing:-.5px;white-space:nowrap}
.hero-stats strong small{font-size:17px;letter-spacing:0}
.hero-stats span{font-size:13px;margin-top:10px}
.hero-visual{min-width:0;min-height:468px;padding-top:20px}
.mock-main{max-width:570px;padding:22px;border-radius:22px}
.mock-head{margin-bottom:20px}
.mock-head em{font-size:12px}
.mock-chat{gap:14px}
.bubble{font-size:15px;line-height:1.85;padding:12px 16px}
.bubble b{font-weight:650}
.chat-note{display:block;font-size:12px;color:var(--muted);padding-top:8px}
.mock-float{padding:18px 22px;border-radius:19px}
.mock-price{bottom:-12px;left:-45px;gap:4px}
.mock-price strong{font-size:25px}
.mock-price .up{color:#226447;font-size:14px}
.mock-avatar{top:-64px;right:-12px}
.mock-avatar strong{font-size:19px;display:block;line-height:1.7}
.mock-avatar small,.mock-price small{font-size:13px}
.avatar{display:grid;place-items:center;color:white;font-size:20px;font-style:italic;font-weight:850;width:50px;height:50px}
.home-footer{display:flex;align-items:center;gap:24px;color:var(--muted);font-size:12px;padding:22px 0;border-top:1px solid #eef1f8}
.home-footer>span:first-child{font-weight:700;letter-spacing:1px}
.home-footer p{flex:1}
.preview-note{color:#778398}
.skip-link{position:fixed;top:-80px;left:16px;z-index:100;padding:12px 16px;background:#fff;border:2px solid var(--primary);border-radius:8px}
.skip-link:focus{top:12px}
a:focus-visible,button:focus-visible{outline:3px solid #2563eb;outline-offset:5px;border-radius:8px}
.nav-toggle{width:40px;height:40px;align-items:center;justify-content:center;flex-direction:column;gap:6px;border:1px solid var(--border);border-radius:10px}
.nav-toggle span{display:block;width:17px;height:2px;background:#334155;transition:transform .2s}
.nav-toggle[aria-expanded="true"] span:first-child{transform:translateY(4px) rotate(45deg)}
.nav-toggle[aria-expanded="true"] span:last-child{transform:translateY(-4px) rotate(-45deg)}
@media(min-width:1800px){.container{width:min(1480px,100% - 120px)}.hero-inner{gap:130px}}
@media(max-width:1280px){.container{width:calc(100% - 64px)}.nav-links{gap:15px;font-size:13px}.brand-name{font-size:19px}.brand-logo{width:34px;height:34px}.hero-inner{gap:64px}.hero-copy .lead{font-size:17px}.hero-stats{gap:24px}.hero-stats strong{font-size:29px}.hero-stats strong small{font-size:14px}.mock-price{left:-24px}.bubble{font-size:14px}}
@media(max-width:1100px){.nav-toggle{display:flex}.nav-links{display:none;position:absolute;left:24px;right:24px;top:72px;background:#fff;border:1px solid var(--border);border-radius:16px;padding:20px;box-shadow:var(--shadow);grid-template-columns:repeat(4,minmax(0,1fr));gap:10px}.nav-links.open{display:grid}.nav-links a{font-size:14px;padding:12px;text-align:center;background:#f5f7fb;border-radius:8px}.hero-inner{gap:40px}.mock-price{left:-12px}.hero-stats{gap:20px}.hero-stats span{font-size:12px}}
@media(max-width:800px){.container{width:calc(100% - 48px)}.nav-inner{height:72px}.hero{padding:62px 0 78px;min-height:0}.hero-inner{grid-template-columns:1fr;gap:64px}.hero-copy{max-width:620px}.hero-copy .lead{max-width:560px}.hero-visual{width:min(570px,100%);margin:auto;min-height:440px}.mock-main{max-width:none}.mock-price{left:-8px;bottom:-5px}.mock-avatar{right:0;top:-20px}.hero-stats{gap:42px}.hero-stats span{font-size:13px}.hero-stats strong small{font-size:16px}.home-footer{gap:16px;flex-wrap:wrap}.home-footer p{flex-basis:60%;text-align:right}.preview-note{display:none}}
@media(max-width:480px){.container{width:calc(100% - 36px)}.nav-inner{gap:8px;height:68px}.brand{gap:7px}.brand-name{font-size:17px}.brand-logo{width:31px;height:31px;font-size:17px}.nav-actions{gap:6px}.nav-actions .btn{padding:9px 11px;font-size:12px;border-radius:9px}.nav-actions .btn span{display:none}.nav-toggle{width:34px;height:34px}.nav-links{left:14px;right:14px;top:62px;padding:12px;grid-template-columns:repeat(2,minmax(0,1fr))}.hero{padding-top:45px;padding-bottom:60px}.tag{font-size:12px;margin-bottom:16px}h1{font-size:44px;letter-spacing:-1.7px}.hero-copy .lead{font-size:15px;margin:23px 0 27px}.hero-cta{gap:10px}.btn-lg{font-size:14px;padding:13px 18px}.hero-stats{gap:0;justify-content:space-between;margin-top:35px}.hero-stats strong{font-size:25px}.hero-stats strong small{font-size:12px}.hero-stats span{font-size:11px;margin-top:6px}.hero-inner{gap:66px}.hero-visual{min-height:445px;padding-top:36px}.mock-main{padding:16px;border-radius:18px}.mock-head em{font-size:10px}.mock-head{margin-bottom:15px}.mock-chat{gap:12px}.bubble{font-size:12px;max-width:95%;padding:10px 12px}.chat-note{font-size:10px}.mock-avatar{top:-16px;padding:11px 15px;gap:9px}.mock-avatar strong{font-size:15px}.mock-avatar small,.mock-price small{font-size:11px}.avatar{width:37px;height:37px;font-size:16px}.mock-price{padding:12px 16px;bottom:-20px;left:0}.mock-price strong{font-size:21px}.mock-price .up{font-size:12px}.home-footer{font-size:10px;gap:9px;padding:18px 0}.home-footer p{letter-spacing:-.3px}}
@media(prefers-reduced-motion:reduce){html{scroll-behavior:auto}*,*::before,*::after{animation:none!important;transition:none!important}}