/* 爱思助手 方案三(重做)· BOLD GRADIENT POSTER / 极限海报
   配色: 紫粉橙黄渐变 + 巨型数字大背景
   字体: 巨型无衬线 + 圆形布局
   关键词布局: Poster / Flash / Verify / Backup / Stack
*/

:root{
  --bg:#0a0612;
  --surface:#1a0f2e;
  --ink:#fff;
  --ink-soft:rgba(255,255,255,.7);
  --line:rgba(255,255,255,.12);
  --purple:#a855f7;
  --pink:#ec4899;
  --orange:#fb923c;
  --yellow:#fbbf24;
  --grad:linear-gradient(135deg,#a855f7 0%,#ec4899 50%,#fb923c 100%);
  --grad-soft:linear-gradient(135deg,rgba(168,85,247,.25),rgba(236,72,153,.25),rgba(251,146,60,.25));
  --max:1280px;
}

*{box-sizing:border-box;margin:0;padding:0}
html{scroll-behavior:smooth}
body{
  background:var(--bg);
  color:var(--ink);
  font-family:"Inter","PingFang SC","Helvetica Neue",system-ui,sans-serif;
  font-size:17px;
  line-height:1.6;
  -webkit-font-smoothing:antialiased;
  overflow-x:hidden;
}
a{color:inherit;text-decoration:none}
img{max-width:100%;display:block}

em{font-family:"Cormorant Garamond",Georgia,serif;font-style:italic;font-weight:500}

/* ===== Topbar ===== */
.bgp-top{
  position:sticky;
  top:0;
  z-index:30;
  display:flex;
  justify-content:space-between;
  align-items:center;
  padding:20px 36px;
  background:rgba(10,6,18,.85);
  backdrop-filter:blur(14px);
  border-bottom:1px solid var(--line);
}
.bgp-brand{display:flex;align-items:center;gap:12px}
.bgp-brand img{width:36px;height:36px;border-radius:9px}
.bgp-brand span{
  font-size:22px;
  font-weight:900;
  letter-spacing:.18em;
  background:var(--grad);
  -webkit-background-clip:text;
  background-clip:text;
  color:transparent;
}
.bgp-top nav{display:flex;align-items:center;gap:28px;font-size:13px;letter-spacing:.14em;text-transform:uppercase;font-weight:700}
.bgp-top nav a{color:rgba(255,255,255,.85);transition:.2s}
.bgp-top nav a:hover{color:var(--yellow)}
.bgp-cta{
  background:var(--grad);
  color:#fff !important;
  padding:12px 22px;
  border-radius:99px;
  letter-spacing:.18em;
  font-weight:700;
}
.bgp-cta:hover{transform:scale(1.04);box-shadow:0 10px 40px rgba(236,72,153,.5)}

/* ===== Poster · 海报 ===== */
.bgp-poster{
  max-width:var(--max);
  margin:0 auto;
  padding:50px 36px 70px;
  text-align:center;
  position:relative;
}
.bgp-pill{
  display:inline-block;
  background:var(--grad);
  color:#fff;
  padding:8px 20px;
  border-radius:99px;
  font-size:13px;
  font-weight:700;
  letter-spacing:.22em;
  margin-bottom:30px;
  text-transform:uppercase;
}
.bgp-hero{
  font-size:clamp(40px,6vw,92px);
  font-weight:900;
  line-height:1;
  letter-spacing:-.04em;
  margin-bottom:28px;
}
.bgp-hero em{
  font-style:normal;
  background:var(--grad);
  -webkit-background-clip:text;
  background-clip:text;
  color:transparent;
  display:inline-block;
}
.bgp-sub{
  font-size:18px;
  color:var(--ink-soft);
  max-width:680px;
  margin:0 auto 50px;
  letter-spacing:.06em;
}

.bgp-poster-img{
  position:relative;
  display:inline-block;
  max-width:680px;
  margin:0 auto 50px;
}
.bgp-poster-img img{
  width:100%;
  border-radius:32px;
  box-shadow:0 30px 80px rgba(168,85,247,.4);
  position:relative;
  z-index:3;
}
.bgp-circle{
  position:absolute;
  border-radius:50%;
  filter:blur(40px);
  z-index:1;
}
.bgp-circle.c1{
  width:280px;height:280px;
  background:var(--purple);
  top:-40px;left:-40px;
  opacity:.6;
}
.bgp-circle.c2{
  width:340px;height:340px;
  background:var(--pink);
  bottom:-60px;right:-60px;
  opacity:.5;
}
.bgp-circle.c3{
  width:220px;height:220px;
  background:var(--orange);
  top:30%;right:-50px;
  opacity:.4;
}
.bgp-tag{
  position:absolute;
  background:rgba(255,255,255,.95);
  color:var(--bg);
  padding:12px 22px;
  border-radius:99px;
  font-size:14px;
  font-weight:800;
  letter-spacing:.16em;
  z-index:4;
  box-shadow:0 12px 30px rgba(0,0,0,.3);
}
.bgp-tag.t1{top:20%;left:-10%}
.bgp-tag.t2{top:50%;right:-8%;background:var(--yellow);color:var(--bg)}
.bgp-tag.t3{bottom:25%;left:-12%;background:var(--grad);color:#fff}
.bgp-tag.t4{top:-10%;right:20%;background:#fff}

.bgp-big-cta{
  display:inline-block;
  background:var(--grad);
  color:#fff;
  padding:24px 56px;
  border-radius:99px;
  font-size:15px;
  font-weight:800;
  letter-spacing:.22em;
  text-transform:uppercase;
  box-shadow:0 18px 50px rgba(168,85,247,.5);
  transition:.25s;
  margin-bottom:40px;
}
.bgp-big-cta:hover{transform:translateY(-3px) scale(1.02);box-shadow:0 22px 70px rgba(236,72,153,.6)}
.bgp-big-cta.pulse{animation:bgp-pulse 2.2s ease-in-out infinite}
@keyframes bgp-pulse{
  0%,100%{box-shadow:0 18px 50px rgba(168,85,247,.5),0 0 0 0 rgba(236,72,153,.5)}
  50%{box-shadow:0 18px 50px rgba(168,85,247,.5),0 0 0 18px rgba(236,72,153,0)}
}

.bgp-scroll{
  font-size:11px;
  letter-spacing:.42em;
  color:var(--ink-soft);
  text-transform:uppercase;
  animation:bounce 2s ease-in-out infinite;
}
@keyframes bounce{
  0%,100%{transform:translateY(0)}
  50%{transform:translateY(8px)}
}

/* ===== Block · 大块功能 ===== */
.bgp-block{
  max-width:var(--max);
  margin:0 auto;
  padding:140px 36px;
  display:grid;
  grid-template-columns:1fr 1fr;
  gap:80px;
  align-items:center;
  position:relative;
  border-top:1px solid var(--line);
}
.bgp-block.flip .bgp-block-img{order:1}
.bgp-block.flip .bgp-block-text{order:2}
.bgp-bg-num{
  position:absolute;
  top:40px;
  left:36px;
  font-size:clamp(180px,18vw,360px);
  font-weight:900;
  line-height:1;
  background:var(--grad);
  -webkit-background-clip:text;
  background-clip:text;
  color:transparent;
  opacity:.12;
  letter-spacing:-.04em;
  z-index:0;
}
.bgp-block-text{
  position:relative;
  z-index:1;
}
.bgp-eyebrow{
  display:inline-block;
  font-size:13px;
  letter-spacing:.32em;
  color:var(--yellow);
  text-transform:uppercase;
  margin-bottom:28px;
  font-weight:700;
}
.bgp-eyebrow.center{display:block;text-align:center}
.bgp-block h2{
  font-size:clamp(48px,6vw,108px);
  font-weight:900;
  line-height:.96;
  letter-spacing:-.04em;
  margin-bottom:32px;
}
.bgp-block h2 em{
  font-style:normal;
  background:var(--grad);
  -webkit-background-clip:text;
  background-clip:text;
  color:transparent;
}
.bgp-block p{
  font-size:18px;
  color:var(--ink-soft);
  line-height:1.7;
  margin-bottom:32px;
  max-width:520px;
}

.bgp-list{list-style:none}
.bgp-list li{
  display:flex;
  gap:20px;
  padding:18px 0;
  border-top:1px solid var(--line);
  align-items:center;
}
.bgp-list li:last-child{border-bottom:1px solid var(--line)}
.bgp-list b{
  font-size:28px;
  font-weight:900;
  background:var(--grad);
  -webkit-background-clip:text;
  background-clip:text;
  color:transparent;
  flex-shrink:0;
  width:42px;
  font-family:"Cormorant Garamond",Georgia,serif;
  font-style:italic;
}
.bgp-list span{font-size:16px;color:var(--ink-soft)}

.bgp-stats{
  display:flex;
  gap:36px;
  margin-top:32px;
  padding-top:32px;
  border-top:1px solid var(--line);
}
.bgp-stats div{display:flex;flex-direction:column}
.bgp-stats b{
  font-size:clamp(40px,5vw,72px);
  font-weight:900;
  background:var(--grad);
  -webkit-background-clip:text;
  background-clip:text;
  color:transparent;
  line-height:1;
}
.bgp-stats span{font-size:13px;color:var(--ink-soft);margin-top:8px}

.bgp-rank{list-style:none;border-top:1px solid var(--line)}
.bgp-rank li{
  display:grid;
  grid-template-columns:60px 1fr auto;
  align-items:center;
  padding:18px 0;
  border-bottom:1px solid var(--line);
}
.bgp-rank b{
  font-family:"Cormorant Garamond",Georgia,serif;
  font-size:36px;
  font-style:italic;
  font-weight:500;
  background:var(--grad);
  -webkit-background-clip:text;
  background-clip:text;
  color:transparent;
  line-height:1;
}
.bgp-rank span{font-size:17px;font-weight:700}
.bgp-rank i{
  font-family:"Cormorant Garamond",Georgia,serif;
  font-style:italic;
  color:var(--yellow);
  font-size:18px;
}

.bgp-block-img{
  position:relative;
  z-index:1;
  border-radius:32px;
  overflow:hidden;
}
.bgp-block-img img{
  width:100%;
  border-radius:32px;
  box-shadow:0 30px 60px rgba(168,85,247,.35);
}

/* ===== Stack · 生态网格 ===== */
.bgp-stack{
  max-width:var(--max);
  margin:0 auto;
  padding:120px 36px;
  border-top:1px solid var(--line);
}
.bgp-stack-title{
  font-size:clamp(48px,6vw,108px);
  font-weight:900;
  line-height:.96;
  letter-spacing:-.04em;
  text-align:center;
  margin-bottom:60px;
}
.bgp-stack-title em{
  font-style:normal;
  background:var(--grad);
  -webkit-background-clip:text;
  background-clip:text;
  color:transparent;
}
.bgp-stack-grid{
  display:grid;
  grid-template-columns:repeat(4,1fr);
  gap:18px;
}
.bgp-stack-card{
  background:rgba(255,255,255,.05);
  border:1px solid var(--line);
  border-radius:24px;
  padding:30px;
  text-align:center;
  transition:.25s;
  backdrop-filter:blur(8px);
}
.bgp-stack-card:hover{
  background:var(--grad-soft);
  border-color:transparent;
  transform:translateY(-6px);
}
.bgp-stack-icon{
  font-size:42px;
  display:block;
  margin-bottom:14px;
}
.bgp-stack-card h4{
  font-size:20px;
  font-weight:800;
  margin-bottom:8px;
  letter-spacing:-.01em;
}
.bgp-stack-card p{
  font-size:14px;
  color:var(--ink-soft);
}

/* ===== Final CTA ===== */
.bgp-final-cta{
  background:var(--grad);
  text-align:center;
  padding:140px 36px;
  position:relative;
  overflow:hidden;
}
.bgp-final-cta::before{
  content:"";
  position:absolute;
  top:-100px;
  left:50%;
  transform:translateX(-50%);
  width:600px;
  height:600px;
  background:rgba(255,255,255,.15);
  border-radius:50%;
  filter:blur(80px);
}
.bgp-final-cta h2{
  position:relative;
  font-size:clamp(56px,8vw,140px);
  font-weight:900;
  line-height:.95;
  letter-spacing:-.04em;
  margin-bottom:50px;
  color:#fff;
}
.bgp-final-cta h2 em{
  font-family:"Cormorant Garamond",Georgia,serif;
  font-style:italic;
  font-weight:500;
  color:var(--yellow);
}
.bgp-final-cta .bgp-big-cta{
  position:relative;
  background:#fff;
  color:var(--bg);
  box-shadow:0 18px 50px rgba(0,0,0,.3);
}
.bgp-final-cta .bgp-big-cta:hover{background:var(--bg);color:#fff}

/* ===== Footer ===== */
.bgp-foot{
  background:#04020a;
  padding:40px 0;
  border-top:1px solid var(--line);
}
.bgp-foot-inner{
  max-width:var(--max);
  margin:0 auto;
  padding:0 36px;
  display:flex;
  justify-content:space-between;
  align-items:center;
}
.bgp-foot img{width:30px;height:30px;border-radius:6px;display:inline-block;vertical-align:middle}
.bgp-foot b{
  font-size:18px;
  font-weight:900;
  letter-spacing:.14em;
  margin-left:10px;
  background:var(--grad);
  -webkit-background-clip:text;
  background-clip:text;
  color:transparent;
}
.bgp-foot p{font-size:11px;letter-spacing:.18em;color:var(--ink-soft);margin-top:6px;text-transform:uppercase}
.bgp-foot-right{display:flex;align-items:center;gap:20px;font-size:12px;letter-spacing:.14em;color:var(--ink-soft);text-transform:uppercase}
.bgp-foot-right a:hover{color:var(--yellow)}

/* ===== 下载页 ===== */
.bgp-dl-poster{
  max-width:var(--max);
  margin:0 auto;
  padding:60px 36px 80px;
  text-align:center;
  position:relative;
}
.bgp-dl-poster .bgp-hero{font-size:clamp(38px,5vw,76px)}
.bgp-dl-poster-img{
  position:relative;
  display:inline-block;
  max-width:640px;
  margin:0 auto 50px;
}
.bgp-dl-poster-img img{
  width:100%;
  border-radius:32px;
  box-shadow:0 30px 80px rgba(168,85,247,.4);
}

.bgp-platforms{
  max-width:var(--max);
  margin:0 auto;
  padding:120px 36px;
  border-top:1px solid var(--line);
}
.bgp-platforms-grid{
  display:grid;
  grid-template-columns:repeat(4,1fr);
  gap:18px;
  margin-top:50px;
}
.bgp-pf-card{
  background:rgba(255,255,255,.05);
  border:1px solid var(--line);
  border-radius:24px;
  padding:32px;
  text-align:center;
  transition:.25s;
  backdrop-filter:blur(8px);
}
.bgp-pf-card.highlight{
  background:var(--grad);
  border-color:transparent;
  transform:scale(1.05);
  box-shadow:0 20px 60px rgba(168,85,247,.5);
}
.bgp-pf-os{
  display:inline-block;
  font-size:11px;
  letter-spacing:.28em;
  font-weight:800;
  color:var(--yellow);
  background:rgba(255,255,255,.08);
  padding:6px 14px;
  border-radius:99px;
  margin-bottom:18px;
  text-transform:uppercase;
}
.bgp-pf-card.highlight .bgp-pf-os{background:rgba(0,0,0,.25);color:#fff}
.bgp-pf-card h3{
  font-size:26px;
  font-weight:900;
  margin-bottom:10px;
  letter-spacing:-.01em;
}
.bgp-pf-card p{font-size:13px;color:var(--ink-soft);margin-bottom:22px;line-height:1.6}
.bgp-pf-btn{
  display:inline-block;
  background:transparent;
  color:#fff;
  border:1.5px solid rgba(255,255,255,.4);
  padding:11px 22px;
  border-radius:99px;
  font-size:12px;
  font-weight:700;
  letter-spacing:.18em;
  transition:.2s;
  text-transform:uppercase;
}
.bgp-pf-btn:hover{background:#fff;color:var(--bg);border-color:#fff}

.bgp-steps{
  max-width:var(--max);
  margin:0 auto;
  padding:120px 36px;
  border-top:1px solid var(--line);
}
.bgp-step{
  display:grid;
  grid-template-columns:160px 1fr;
  gap:48px;
  padding:48px 0;
  border-top:1px solid var(--line);
  align-items:start;
  max-width:980px;
  margin:0 auto;
}
.bgp-step:last-child{border-bottom:1px solid var(--line)}
.bgp-step.flip{grid-template-columns:1fr 160px}
.bgp-step.flip > div{order:2}
.bgp-step.flip .bgp-sn{order:1;text-align:right}
.bgp-sn{
  font-size:clamp(96px,12vw,160px);
  font-weight:900;
  background:var(--grad);
  -webkit-background-clip:text;
  background-clip:text;
  color:transparent;
  line-height:.85;
  letter-spacing:-.04em;
}
.bgp-step h4{
  font-size:32px;
  font-weight:800;
  margin-bottom:14px;
  letter-spacing:-.01em;
}
.bgp-step p{font-size:17px;color:var(--ink-soft);line-height:1.7}

.bgp-req{
  max-width:var(--max);
  margin:0 auto;
  padding:120px 36px;
  border-top:1px solid var(--line);
}
.bgp-req-grid{
  display:grid;
  grid-template-columns:repeat(4,1fr);
  gap:18px;
  margin-top:50px;
}
.bgp-req-card{
  background:rgba(255,255,255,.05);
  border:1px solid var(--line);
  border-radius:24px;
  padding:30px;
  transition:.25s;
}
.bgp-req-card.highlight{
  background:var(--grad);
  border-color:transparent;
  transform:scale(1.04);
}
.bgp-req-os{
  display:inline-block;
  font-size:11px;
  letter-spacing:.28em;
  font-weight:800;
  color:var(--yellow);
  background:rgba(255,255,255,.08);
  padding:6px 14px;
  border-radius:99px;
  margin-bottom:18px;
  text-transform:uppercase;
}
.bgp-req-card.highlight .bgp-req-os{background:rgba(0,0,0,.25);color:#fff}
.bgp-req-card h3{
  font-size:26px;
  font-weight:900;
  margin-bottom:14px;
  letter-spacing:-.01em;
}
.bgp-req-card p{font-size:14px;color:var(--ink-soft);line-height:1.6}

/* ===== 响应式 ===== */
@media (max-width:1100px){
  .bgp-top{padding:16px 22px;flex-wrap:wrap;gap:14px}
  .bgp-top nav{gap:18px;font-size:12px}
  .bgp-block,.bgp-block.flip{grid-template-columns:1fr;gap:40px;padding:80px 22px}
  .bgp-block.flip .bgp-block-img{order:0}
  .bgp-block.flip .bgp-block-text{order:0}
  .bgp-stack-grid,.bgp-platforms-grid,.bgp-req-grid{grid-template-columns:1fr 1fr}
  .bgp-step,.bgp-step.flip{grid-template-columns:1fr;gap:18px}
  .bgp-step.flip > div,.bgp-step.flip .bgp-sn{order:0;text-align:left}
  .bgp-foot-inner{flex-direction:column;gap:18px;align-items:flex-start}
  .bgp-pf-card.highlight,.bgp-req-card.highlight{transform:none}
  .bgp-tag.t1{left:2%}.bgp-tag.t2{right:2%}.bgp-tag.t3{left:0}.bgp-tag.t4{display:none}
}
@media (max-width:560px){
  body{font-size:15px}
  .bgp-hero,.bgp-dl-poster .bgp-hero{font-size:42px}
  .bgp-stack-grid,.bgp-platforms-grid,.bgp-req-grid{grid-template-columns:1fr}
  .bgp-block h2,.bgp-stack-title{font-size:38px}
  .bgp-sn{font-size:80px}
  .bgp-final-cta h2{font-size:46px}
  .bgp-step h4{font-size:22px}
  .bgp-poster{padding:40px 22px 60px}
}

/* ===== Floating Download Button · 全局 FAB ===== */
.dl-fab{
  position:fixed;
  right:28px;
  bottom:28px;
  z-index:50;
  display:flex;
  align-items:center;
  gap:10px;
  padding:14px 22px 14px 16px;
  background:var(--ink);
  color:#fff;
  border:1px solid rgba(255,255,255,.18);
  border-radius:99px;
  font-family:"Inter","Helvetica Neue",sans-serif;
  font-size:13px;
  font-weight:800;
  letter-spacing:.22em;
  text-transform:uppercase;
  box-shadow:0 18px 50px -10px rgba(168,85,247,.6);
  transition:.25s;
  text-decoration:none;
}
.dl-fab:hover{
  background:var(--grad);
  border-color:transparent;
  transform:translateY(-3px);
  box-shadow:0 24px 70px -10px rgba(236,72,153,.7);
  color:#fff;
}
.dl-fab .fab-ico{
  width:36px;height:36px;
  display:flex;align-items:center;justify-content:center;
  background:var(--grad);
  color:#fff;
  border-radius:50%;
  font-size:18px;
  transition:.25s;
}
.dl-fab:hover .fab-ico{background:#fff;color:var(--bg)}
.dl-fab .fab-ico svg{width:16px;height:16px;display:block}
.dl-fab .fab-text{
  display:flex;flex-direction:column;line-height:1.1;
}
.dl-fab .fab-title{font-size:13px;letter-spacing:.18em}
.dl-fab .fab-sub{font-size:9px;letter-spacing:.32em;color:var(--yellow);margin-top:3px;font-weight:700}
@media (max-width:560px){
  .dl-fab{
    right:14px;bottom:14px;
    padding:10px 14px 10px 12px;
    gap:8px;
  }
  .dl-fab .fab-ico{width:32px;height:32px;font-size:15px}
  .dl-fab .fab-title{font-size:11px}
  .dl-fab .fab-sub{font-size:8px}
}