:root{
  --blue:#2563eb; --cyan:#22d3ee; --ink:#0b1220; --ink2:#111a2e;
  --bg:#f5f8fe; --card:#ffffff; --line:#e6ecf6;
  --text:#1f2937; --muted:#64748b; --ok:#10b981; --warn:#f59e0b;
  --radius:14px; --shadow:0 10px 30px rgba(15,23,42,.08);
  --shadow-lg:0 20px 50px rgba(15,23,42,.14);
  --grad:linear-gradient(120deg,#22d3ee 0%,#2563eb 100%);
}
*{box-sizing:border-box}
html,body{margin:0;padding:0}
body{
  font-family:"PingFang SC","Microsoft YaHei",-apple-system,"Segoe UI",Roboto,Arial,sans-serif;
  background:var(--bg); color:var(--text); line-height:1.6; -webkit-font-smoothing:antialiased;
}
a{color:inherit;text-decoration:none}
img{max-width:100%}
.wrap{max-width:1160px;margin:0 auto;padding:0 22px}
.btn{
  display:inline-flex;align-items:center;gap:8px;cursor:pointer;border:none;
  padding:11px 20px;border-radius:10px;font-size:15px;font-weight:600;transition:.18s;
}
.btn-primary{background:var(--grad);color:#fff;box-shadow:0 8px 20px rgba(37,99,235,.28)}
.btn-primary:hover{transform:translateY(-2px);box-shadow:0 12px 28px rgba(37,99,235,.38)}
.btn-ghost{background:#eef3ff;color:var(--blue)}
.btn-ghost:hover{background:#e2ebff}
.btn-line{border:1px solid var(--line);background:#fff;color:var(--text)}
.btn-line:hover{border-color:var(--blue);color:var(--blue)}
.tag{display:inline-block;font-size:12px;padding:3px 10px;border-radius:999px;background:#eef3ff;color:var(--blue);font-weight:600}

/* NAV */
.nav{position:sticky;top:0;z-index:50;background:rgba(255,255,255,.82);backdrop-filter:blur(12px);border-bottom:1px solid var(--line)}
.nav .wrap{display:flex;align-items:center;justify-content:space-between;height:64px}
.nav .logo{display:flex;align-items:center;gap:10px;font-weight:800;font-size:18px}
.nav .logo img{height:34px}
.nav ul{display:flex;gap:26px;list-style:none;margin:0;padding:0;font-weight:600;font-size:15px}
.nav ul a:hover{color:var(--blue)}
.nav .right{display:flex;align-items:center;gap:12px}
.brand-mini{font-size:12px;color:var(--muted);font-weight:600}

/* HERO */
.hero{position:relative;overflow:hidden;background:radial-gradient(1200px 600px at 70% -10%,rgba(34,211,238,.25),transparent),linear-gradient(180deg,#0b1220,#111a2e)}
.hero .wrap{padding:74px 22px 84px;color:#e8eefc}
.hero h1{font-size:42px;line-height:1.2;margin:0 0 16px;font-weight:800}
.hero h1 .ac{background:var(--grad);-webkit-background-clip:text;background-clip:text;color:transparent}
.hero p.lead{font-size:18px;color:#b8c4de;max-width:640px;margin:0 0 28px}
.hero .cta{display:flex;gap:14px;flex-wrap:wrap}
.hero .pill{display:inline-flex;gap:8px;align-items:center;background:rgba(255,255,255,.08);border:1px solid rgba(255,255,255,.14);color:#cfe0ff;padding:6px 14px;border-radius:999px;font-size:13px;margin-bottom:22px}
.glow{position:absolute;width:480px;height:480px;border-radius:50%;filter:blur(90px);opacity:.5;right:-120px;top:-120px;background:radial-gradient(circle,#22d3ee,transparent 60%)}

/* SECTION */
.section{padding:64px 0}
.section.alt{background:#eef3fc}
.head{text-align:center;margin-bottom:40px}
.head .tag{margin-bottom:12px}
.head h2{font-size:30px;margin:0 0 10px;font-weight:800}
.head p{color:var(--muted);font-size:16px;margin:0}

/* TOOL CARDS */
.cards{display:grid;grid-template-columns:repeat(2,1fr);gap:24px}
.card{background:var(--card);border:1px solid var(--line);border-radius:var(--radius);padding:30px;box-shadow:var(--shadow);transition:.2s;display:flex;flex-direction:column}
.card:hover{transform:translateY(-4px);box-shadow:var(--shadow-lg);border-color:#cfe0ff}
.card .ico{width:56px;height:56px;border-radius:14px;background:var(--grad);display:flex;align-items:center;justify-content:center;font-size:28px;margin-bottom:18px}
.card h3{margin:0 0 8px;font-size:21px}
.card p{color:var(--muted);margin:0 0 18px;flex:1}
.card .meta{font-size:13px;color:var(--blue);font-weight:600;margin-bottom:16px}

/* TIMELINE */
.timeline{position:relative;max-width:760px;margin:0 auto;padding-left:24px}
.timeline:before{content:"";position:absolute;left:6px;top:6px;bottom:6px;width:2px;background:var(--line)}
.tl-item{position:relative;padding:0 0 26px 26px}
.tl-item:before{content:"";position:absolute;left:-22px;top:6px;width:12px;height:12px;border-radius:50%;background:var(--grad);box-shadow:0 0 0 4px #fff}
.tl-date{font-weight:700;color:var(--blue);font-size:14px}
.tl-text{color:var(--muted);font-size:15px}

/* FOOTER */
.footer{background:var(--ink);color:#9fb0cc;padding:46px 0 30px}
.footer .grid{display:grid;grid-template-columns:1.4fr 1fr 1fr;gap:30px}
.footer h4{color:#fff;font-size:15px;margin:0 0 14px}
.footer a{color:#9fb0cc;display:block;margin-bottom:8px;font-size:14px}
.footer a:hover{color:#7dd3fc}
.footer .copy{border-top:1px solid rgba(255,255,255,.08);margin-top:30px;padding-top:18px;font-size:13px;color:#6b7c99;display:flex;justify-content:space-between;flex-wrap:wrap;gap:10px}

/* TOOL PAGE LAYOUT */
.tool-hero{background:linear-gradient(180deg,#0b1220,#111a2e);color:#e8eefc;padding:40px 0}
.tool-hero h1{font-size:30px;margin:0 0 8px;font-weight:800}
.tool-hero p{color:#b8c4de;margin:0}
.back{display:inline-flex;align-items:center;gap:6px;color:#7dd3fc;font-size:14px;font-weight:600;margin-bottom:14px}
.tool-layout{display:grid;grid-template-columns:340px 1fr;gap:22px;align-items:start;padding:26px 0 60px}
.panel{background:var(--card);border:1px solid var(--line);border-radius:var(--radius);padding:18px;box-shadow:var(--shadow)}
.panel h3.seg{font-size:14px;margin:0 0 12px;color:var(--blue);display:flex;align-items:center;gap:8px}
.field{margin-bottom:14px}
.field label{display:block;font-size:13px;color:var(--muted);margin-bottom:6px;font-weight:600}
.field input[type=number],.field input[type=text],.field select{
  width:100%;padding:9px 11px;border:1px solid var(--line);border-radius:9px;font-size:14px;background:#fff;color:var(--text)
}
.field input:focus,.field select:focus{outline:none;border-color:var(--blue);box-shadow:0 0 0 3px rgba(37,99,235,.12)}
.row2{display:grid;grid-template-columns:1fr 1fr;gap:10px}
.seg-toggle{display:flex;gap:8px}
.seg-toggle button{flex:1;padding:9px;border:1px solid var(--line);background:#fff;border-radius:9px;cursor:pointer;font-weight:600;font-size:14px;color:var(--muted)}
.seg-toggle button.on{background:var(--grad);color:#fff;border-color:transparent}
.adv{margin-top:10px;border-top:1px dashed var(--line);padding-top:12px}
.adv summary{cursor:pointer;font-weight:700;color:var(--text);font-size:14px}
.adv[open] summary{color:var(--blue)}
canvas{display:block;width:100%;height:auto;background:#fff;border-radius:10px;border:1px solid var(--line)}
.canvas-box{background:var(--card);border:1px solid var(--line);border-radius:var(--radius);padding:16px;box-shadow:var(--shadow);margin-bottom:18px}
.canvas-box .ch{display:flex;justify-content:space-between;align-items:center;margin-bottom:12px;flex-wrap:wrap;gap:10px}
.canvas-box .ch h3{font-size:16px;margin:0}
.export-btns{display:flex;gap:8px;flex-wrap:wrap}
.stat-grid{display:grid;grid-template-columns:repeat(2,1fr);gap:10px;margin-top:14px}
.stat{background:#f5f8fe;border:1px solid var(--line);border-radius:10px;padding:10px 12px}
.stat .k{font-size:12px;color:var(--muted)}
.stat .v{font-size:17px;font-weight:800;color:var(--ink)}
.note{font-size:12px;color:var(--muted);margin-top:8px}
.toast{position:fixed;left:50%;bottom:30px;transform:translateX(-50%);background:var(--ink);color:#fff;padding:12px 20px;border-radius:10px;font-size:14px;opacity:0;transition:.3s;z-index:99;pointer-events:none}
.toast.show{opacity:1}
@media(max-width:880px){
  .cards{grid-template-columns:1fr}
  .tool-layout{grid-template-columns:1fr}
  .hero h1{font-size:32px}
  .nav ul{display:none}
  .footer .grid{grid-template-columns:1fr}
}