/* ===== Aurora Glass · 极光玻璃 · au- ===== */
:root{
  --au-bg1:#cdeffd;
  --au-bg2:#e7d9ff;
  --au-bg3:#ffe3d8;
  --au-ink:#1c2740;
  --au-muted:#52607e;
  --au-accent:#7c5cff;
  --au-glass:rgba(255,255,255,.42);
  --au-glass-line:rgba(255,255,255,.7);
  --au-radius:22px;
  --au-maxw:1120px;
  --au-font:"PingFang SC","Hiragano Sans GB","Microsoft YaHei",-apple-system,BlinkMacSystemFont,"Segoe UI",Roboto,Helvetica,Arial,sans-serif;
  --au-ease:cubic-bezier(.2,.8,.2,1);
}
*{box-sizing:border-box;margin:0;padding:0}
html{scroll-behavior:smooth}
body{font-family:var(--au-font);background:var(--au-bg2);color:var(--au-ink);line-height:1.7;-webkit-font-smoothing:antialiased;overflow-x:hidden}
a{color:inherit;text-decoration:none}
.au-wrap{max-width:var(--au-maxw);margin:0 auto;padding:0 24px}

/* aurora bg */
.au-aurora{position:fixed;inset:-20%;z-index:-1;
  background:
    radial-gradient(40% 50% at 20% 25%, var(--au-bg1) 0%, transparent 60%),
    radial-gradient(45% 55% at 80% 30%, var(--au-bg2) 0%, transparent 60%),
    radial-gradient(50% 60% at 55% 85%, var(--au-bg3) 0%, transparent 60%),
    linear-gradient(120deg,#eef4ff,#f3ecff 50%,#fff3ee);
  filter:blur(20px);
  animation:auShift 18s ease-in-out infinite alternate;
}
@keyframes auShift{0%{transform:translate(0,0) scale(1)}100%{transform:translate(2%,-2%) scale(1.06)}}

/* header */
.au-head{position:sticky;top:0;z-index:50}
.au-bar{max-width:var(--au-maxw);margin:14px auto;padding:12px 22px;width:calc(100% - 32px);
  display:flex;align-items:center;justify-content:space-between;gap:20px;
  background:var(--au-glass);backdrop-filter:blur(14px);-webkit-backdrop-filter:blur(14px);
  border:1px solid var(--au-glass-line);border-radius:18px}
.au-brand{display:flex;align-items:center;gap:10px;font-weight:800;font-size:19px}
.au-orb{width:20px;height:20px;border-radius:50%;background:radial-gradient(circle at 30% 30%,#fff,#7c5cff 60%,#cdeffd);box-shadow:0 0 14px rgba(124,92,255,.6)}
.au-brandtext em{font-style:normal;font-size:11px;font-weight:800;letter-spacing:1px;margin-left:8px;color:var(--au-accent)}
.au-nav{display:flex;gap:26px;font-weight:700}
.au-nav a{position:relative;padding:4px 0}
.au-nav a::after{content:"";position:absolute;left:0;bottom:0;width:0;height:2px;background:var(--au-accent);transition:width .25s var(--au-ease)}
.au-nav a:hover::after{width:100%}
.au-burger{display:none;flex-direction:column;gap:5px;background:none;border:1px solid var(--au-ink);border-radius:10px;padding:8px;cursor:pointer}
.au-burger span{width:22px;height:2px;background:var(--au-ink);display:block}

/* hero */
.au-hero{padding:90px 0 70px;position:relative}
.au-hero::before{content:"";position:absolute;width:420px;height:420px;border-radius:50%;
  background:radial-gradient(circle,rgba(124,92,255,.28),transparent 70%);top:-60px;right:-40px;pointer-events:none}
.au-hero-in{max-width:760px;position:relative}
.au-chip{display:inline-block;background:var(--au-glass);border:1px solid var(--au-glass-line);backdrop-filter:blur(10px);border-radius:30px;padding:6px 16px;font-weight:700;font-size:13px;color:var(--au-accent);margin-bottom:22px}
.au-h1{font-size:clamp(38px,6.6vw,72px);line-height:1.05;font-weight:800;letter-spacing:-1px}
.au-lead{margin-top:24px;font-size:clamp(16px,2vw,19px);max-width:620px;color:var(--au-muted)}
.au-cta{margin-top:34px;display:flex;gap:16px;flex-wrap:wrap}
.au-btn{display:inline-flex;align-items:center;gap:8px;font-weight:700;border-radius:40px;padding:13px 26px;transition:transform .2s var(--au-ease),box-shadow .2s var(--au-ease)}
.au-btn-solid{background:linear-gradient(120deg,#7c5cff,#5ca8ff);color:#fff;box-shadow:0 10px 30px rgba(124,92,255,.35)}
.au-btn-solid:hover{transform:translateY(-3px);box-shadow:0 16px 38px rgba(124,92,255,.45)}
.au-btn-ghost{background:var(--au-glass);border:1px solid var(--au-glass-line);backdrop-filter:blur(10px)}
.au-btn-ghost:hover{transform:translateY(-3px)}
.au-arr{transition:transform .2s var(--au-ease)}
.au-btn:hover .au-arr{transform:translateX(4px)}

/* glass card base */
.au-card,.au-row,.au-step,.au-item{background:var(--au-glass);backdrop-filter:blur(14px);-webkit-backdrop-filter:blur(14px);border:1px solid var(--au-glass-line);border-radius:var(--au-radius);box-shadow:0 8px 28px rgba(40,50,90,.08)}

/* sections */
.au-sec{padding:72px 0;position:relative}
.au-sec-alt{}
.au-sec-head{display:flex;align-items:baseline;gap:14px;margin-bottom:22px}
.au-no{font-size:13px;font-weight:800;background:var(--au-ink);color:#fff;padding:4px 12px;border-radius:20px}
.au-sec-head h2{font-size:clamp(26px,4vw,38px);font-weight:800;letter-spacing:-.5px}
.au-lead-c{font-size:17px;max-width:720px;margin-bottom:30px;color:var(--au-muted)}

.au-cards2{display:grid;grid-template-columns:1fr 1fr;gap:22px}
.au-card{padding:28px;transition:transform .25s var(--au-ease),box-shadow .25s var(--au-ease)}
.au-card h3{font-size:20px;font-weight:800;margin-bottom:10px}
.au-card p{font-size:15px;color:var(--au-muted)}
.au-card:hover{transform:translateY(-6px);box-shadow:0 18px 40px rgba(40,50,90,.16)}

.au-list{display:flex;flex-direction:column;gap:14px}
.au-row{display:flex;align-items:center;gap:18px;padding:18px 22px;transition:transform .2s var(--au-ease)}
.au-row:hover{transform:translateX(8px)}
.au-row p{font-size:15px;color:var(--au-muted)}
.au-pill{font-weight:800;color:#fff;padding:8px 16px;border-radius:30px;white-space:nowrap;background:linear-gradient(120deg,#7c5cff,#5ca8ff)}

.au-grid4{display:grid;grid-template-columns:repeat(4,1fr);gap:20px}

.au-steps{display:grid;grid-template-columns:repeat(4,1fr);gap:18px}
.au-step{padding:24px 20px;position:relative;overflow:hidden;transition:transform .25s var(--au-ease)}
.au-step:hover{transform:translateY(-6px)}
.au-step-no{font-size:32px;font-weight:800;color:var(--au-accent);display:block;line-height:1}
.au-step b{font-size:18px;display:block;margin:8px 0 4px}
.au-step span{font-size:14px;color:var(--au-muted)}

.au-faq{display:flex;flex-direction:column;gap:14px}
.au-item{padding:0;overflow:hidden}
.au-item summary{list-style:none;cursor:pointer;padding:18px 22px;font-weight:700;font-size:17px;display:flex;justify-content:space-between;align-items:center}
.au-item summary::-webkit-details-marker{display:none}
.au-chev{font-style:normal;font-size:24px;font-weight:800;color:var(--au-accent);transition:transform .25s var(--au-ease)}
.au-item[open] .au-chev{transform:rotate(45deg)}
.au-item p{padding:0 22px 20px;font-size:15px;color:var(--au-muted)}

/* footer */
.au-foot{margin-top:30px;border-top:1px solid var(--au-glass-line);background:var(--au-glass);backdrop-filter:blur(14px)}
.au-foot-in{display:flex;justify-content:space-between;align-items:center;padding:26px 24px;flex-wrap:wrap;gap:10px;font-weight:700}
.au-foot-r{color:var(--au-accent);font-size:13px}

/* top */
.au-top{position:fixed;right:22px;bottom:22px;z-index:60;width:48px;height:48px;border-radius:50%;background:linear-gradient(120deg,#7c5cff,#5ca8ff);color:#fff;display:flex;align-items:center;justify-content:center;font-size:22px;font-weight:800;box-shadow:0 10px 28px rgba(124,92,255,.4);opacity:0;pointer-events:none;transition:opacity .3s}
.au-top.show{opacity:1;pointer-events:auto}

/* cursor glow */
.au-glow{position:fixed;width:380px;height:380px;border-radius:50%;pointer-events:none;z-index:0;
  background:radial-gradient(circle,rgba(124,92,255,.18),transparent 70%);
  transform:translate(-50%,-50%);left:var(--gx,50%);top:var(--gy,50%);transition:opacity .3s;opacity:0}
.au-glow.on{opacity:1}

/* reveal */
.reveal{opacity:0;transform:translateY(26px);transition:opacity .6s var(--au-ease),transform .6s var(--au-ease)}
.reveal.in{opacity:1;transform:none}

@media(max-width:900px){
  .au-grid4,.au-steps{grid-template-columns:repeat(2,1fr)}
  .au-cards2{grid-template-columns:1fr}
}
@media(max-width:680px){
  .au-nav{position:fixed;top:78px;right:16px;flex-direction:column;background:var(--au-glass);backdrop-filter:blur(14px);border:1px solid var(--au-glass-line);border-radius:16px;padding:16px 24px;gap:14px;transform:translateY(-160%);opacity:0;transition:transform .25s,opacity .25s;z-index:49}
  .au-nav.open{transform:none;opacity:1}
  .au-burger{display:flex}
  .au-grid4,.au-steps{grid-template-columns:1fr}
  .au-row{flex-direction:column;align-items:flex-start;gap:10px}
  .au-hero{padding:56px 0 44px}
}
@media(prefers-reduced-motion:reduce){
  *{animation:none!important;transition:none!important}
  .reveal{opacity:1;transform:none}
}