/* ============= AILong 个人站 · 现代精致版 ============= */
:root{
  --blue:#2563eb;
  --blue-deep:#1d4ed8;
  --violet:#7c3aed;
  --indigo:#4f46e5;
  --pink:#ec4899;
  --ink:#0b1120;
  --ink-2:#475569;
  --ink-3:#94a3b8;
  --bg:#fafbff;
  --card:#ffffff;
  --line:#e6eaf2;
  --line-soft:#eef1f8;
  --grad:linear-gradient(135deg,#2563eb 0%,#7c3aed 50%,#ec4899 100%);
  --grad-cool:linear-gradient(135deg,#2563eb 0%,#7c3aed 100%);
  --grad-soft:linear-gradient(135deg,#eef2ff 0%,#fdf4ff 50%,#fff1f2 100%);
  --grad-soft-2:linear-gradient(135deg,#eff6ff 0%,#f5f3ff 100%);
  --grad-card:linear-gradient(135deg,rgba(37,99,235,.04) 0%,rgba(124,58,237,.04) 100%);
  --shadow-sm:0 1px 2px rgba(15,23,42,.04),0 2px 8px rgba(15,23,42,.04);
  --shadow-md:0 4px 12px rgba(15,23,42,.06),0 8px 24px rgba(15,23,42,.06);
  --shadow-lg:0 10px 30px rgba(79,70,229,.12),0 24px 60px rgba(79,70,229,.10);
  --radius:20px;
  --radius-sm:12px;
  --radius-lg:28px;
  --font-display:-apple-system,BlinkMacSystemFont,"PingFang SC","Hiragino Sans GB","Microsoft YaHei",system-ui,sans-serif;
}
*{margin:0;padding:0;box-sizing:border-box}
html{scroll-behavior:smooth;scroll-padding-top:80px;-webkit-text-size-adjust:100%}
body{
  font-family:var(--font-display);
  color:var(--ink);
  background:var(--bg);
  line-height:1.75;
  -webkit-font-smoothing:antialiased;
  text-rendering:optimizeLegibility;
}
::selection{background:#c7d2fe;color:var(--ink)}
a{color:inherit;text-decoration:none}
img{max-width:100%}

/* ============= 噪点纹理背景 ============= */
body::before{
  content:'';
  position:fixed;
  inset:0;
  pointer-events:none;
  z-index:0;
  opacity:.4;
  background-image:url("data:image/svg+xml;utf8,<svg xmlns='http://www.w3.org/2000/svg' width='200' height='200'><filter id='n'><feTurbulence type='fractalNoise' baseFrequency='.85' numOctaves='2' stitchTiles='stitch'/><feColorMatrix values='0 0 0 0 0  0 0 0 0 0  0 0 0 0 0  0 0 0 .03 0'/></filter><rect width='100%' height='100%' filter='url(%23n)'/></svg>");
}

/* ============= 通用容器 ============= */
main,nav,header,section,footer{position:relative;z-index:1}

/* ============= 导航 ============= */
nav{
  position:fixed;top:0;left:0;right:0;z-index:100;
  background:rgba(255,255,255,.72);
  backdrop-filter:saturate(180%) blur(20px);
  -webkit-backdrop-filter:saturate(180%) blur(20px);
  border-bottom:1px solid rgba(231,235,245,.6);
  transition:all .3s ease;
}
.nav-in{max-width:1180px;margin:0 auto;padding:0 28px;height:64px;display:flex;align-items:center;justify-content:space-between}
.logo{display:flex;align-items:center;gap:10px;font-weight:800;font-size:17px;letter-spacing:-.2px}
.logo-mark{
  width:32px;height:32px;border-radius:10px;
  background:var(--grad-cool);
  display:flex;align-items:center;justify-content:center;
  color:#fff;font-size:13px;font-weight:800;
  box-shadow:0 4px 12px rgba(99,102,241,.3);
  position:relative;overflow:hidden;
}
.logo-mark::after{
  content:'';position:absolute;inset:0;
  background:linear-gradient(135deg,transparent 40%,rgba(255,255,255,.4) 50%,transparent 60%);
  animation:shine 3s infinite;
}
@keyframes shine{0%,100%{transform:translateX(-100%)}50%{transform:translateX(100%)}}
.nav-links{display:flex;gap:8px;font-size:14.5px;color:var(--ink-2);align-items:center;background:rgba(241,243,250,.6);padding:4px;border-radius:999px}
.nav-links a{padding:7px 16px;border-radius:999px;transition:all .25s;font-weight:500}
.nav-links a:hover{color:var(--blue);background:rgba(255,255,255,.7)}
.nav-links a.active{color:#fff;background:var(--grad-cool);font-weight:600;box-shadow:0 4px 12px rgba(99,102,241,.3)}
.nav-cta{padding:8px 18px;border-radius:999px;background:var(--ink);color:#fff!important;font-weight:600;font-size:13.5px;margin-left:8px;transition:all .25s}
.nav-cta:hover{background:var(--grad-cool);transform:translateY(-1px)}
.menu-btn{display:none;background:rgba(241,243,250,.8);border:none;font-size:18px;cursor:pointer;color:var(--ink);width:40px;height:40px;border-radius:12px}
@media(max-width:880px){
  .nav-links{display:none;position:absolute;top:64px;left:0;right:0;background:rgba(255,255,255,.95);backdrop-filter:blur(20px);flex-direction:column;padding:14px 24px;gap:6px;align-items:stretch;border-bottom:1px solid var(--line);box-shadow:0 12px 24px rgba(15,23,42,.08);border-radius:0}
  .nav-links a{text-align:center;padding:12px}
  .nav-links.open{display:flex}
  .menu-btn{display:flex;align-items:center;justify-content:center}
}

/* ============= Hero ============= */
header.hero{
  background:
    radial-gradient(1100px 600px at 85% -10%,rgba(236,72,153,.25),transparent 55%),
    radial-gradient(900px 500px at 5% 110%,rgba(37,99,235,.30),transparent 55%),
    linear-gradient(160deg,#0b1120 0%,#111c3a 55%,#1e1b4b 100%);
  color:#e2e8f0;
  padding:160px 28px 110px;
  position:relative;overflow:hidden;
}
header.hero::before{
  content:'';position:absolute;inset:0;
  background:radial-gradient(circle at 20% 50%,rgba(124,58,237,.2),transparent 40%);
  pointer-events:none;
}
header.hero::after{
  content:'';position:absolute;inset:0;
  background-image:
    linear-gradient(rgba(255,255,255,.05) 1px,transparent 1px),
    linear-gradient(90deg,rgba(255,255,255,.05) 1px,transparent 1px);
  background-size:48px 48px;
  mask-image:radial-gradient(ellipse 80% 60% at 50% 30%,#000 30%,transparent 80%);
  -webkit-mask-image:radial-gradient(ellipse 80% 60% at 50% 30%,#000 30%,transparent 80%);
  pointer-events:none;
}
.hero-in{max-width:1080px;margin:0 auto;position:relative;z-index:2}
.hero-tag{
  display:inline-flex;align-items:center;gap:8px;
  font-size:12.5px;color:#c4b5fd;
  background:rgba(167,139,250,.12);
  border:1px solid rgba(167,139,250,.3);
  padding:7px 16px;border-radius:999px;
  margin-bottom:30px;
  backdrop-filter:blur(8px);
  letter-spacing:.3px;
}
.hero-tag .dot{width:6px;height:6px;border-radius:50%;background:#34d399;box-shadow:0 0 0 4px rgba(52,211,153,.2);animation:pulse 2.5s infinite}
@keyframes pulse{0%,100%{transform:scale(1);opacity:1}50%{transform:scale(.85);opacity:.5}}
header.hero h1{
  font-size:clamp(36px,5.8vw,64px);
  font-weight:800;
  letter-spacing:-1.2px;
  line-height:1.1;
  color:#fff;
  margin-bottom:0;
}
.grad-text{
  background:linear-gradient(120deg,#60a5fa 0%,#a78bfa 50%,#f0abfc 100%);
  -webkit-background-clip:text;background-clip:text;
  -webkit-text-fill-color:transparent;
  display:inline-block;
}
.hero-sub{margin-top:24px;font-size:clamp(17px,2.2vw,21px);color:#e2e8f0;max-width:660px;font-weight:400;line-height:1.6}
.hero-desc{margin-top:16px;font-size:15.5px;color:#94a3b8;max-width:660px;line-height:1.7}
.hero-cta{display:flex;gap:14px;margin-top:40px;flex-wrap:wrap}
.btn{
  display:inline-flex;align-items:center;gap:8px;
  padding:13px 26px;border-radius:14px;
  font-weight:600;font-size:14.5px;
  transition:all .25s cubic-bezier(.4,0,.2,1);
  cursor:pointer;border:none;
  font-family:inherit;
  letter-spacing:.2px;
}
.btn-primary{
  background:var(--grad-cool);
  color:#fff;
  box-shadow:0 8px 24px rgba(99,102,241,.4);
  position:relative;overflow:hidden;
}
.btn-primary::before{
  content:'';position:absolute;inset:0;
  background:linear-gradient(120deg,transparent 30%,rgba(255,255,255,.25) 50%,transparent 70%);
  transform:translateX(-100%);
  transition:transform .6s ease;
}
.btn-primary:hover{transform:translateY(-2px);box-shadow:0 12px 30px rgba(99,102,241,.55)}
.btn-primary:hover::before{transform:translateX(100%)}
.btn-ghost{
  background:rgba(255,255,255,.06);
  color:#e2e8f0;
  border:1px solid rgba(255,255,255,.18);
  backdrop-filter:blur(8px);
}
.btn-ghost:hover{background:rgba(255,255,255,.12);border-color:rgba(255,255,255,.3)}
.btn-outline{
  background:var(--card);color:var(--blue-deep);
  border:1px solid #c7d2fe;
  box-shadow:var(--shadow-sm);
}
.btn-outline:hover{background:#eff6ff;border-color:var(--blue);transform:translateY(-1px)}
.hero-stats{
  display:grid;grid-template-columns:repeat(4,1fr);
  margin-top:72px;gap:0;
  border-top:1px solid rgba(148,163,184,.15);
  padding-top:36px;
}
.stat{padding:0 28px;border-right:1px solid rgba(148,163,184,.12);position:relative}
.stat:first-child{padding-left:0}
.stat:last-child{border-right:none;padding-right:0}
.stat-num{
  font-size:clamp(28px,3.6vw,42px);
  font-weight:800;color:#fff;
  background:linear-gradient(120deg,#93c5fd,#c4b5fd 60%,#f0abfc);
  -webkit-background-clip:text;background-clip:text;
  -webkit-text-fill-color:transparent;
  letter-spacing:-1px;
  line-height:1.1;
}
.stat-label{font-size:13px;color:#94a3b8;margin-top:8px;letter-spacing:.3px}
@media(max-width:720px){
  .hero-stats{grid-template-columns:repeat(2,1fr);gap:16px 0}
  .stat{border-right:none;padding:0}
  .stat:nth-child(odd){border-right:1px solid rgba(148,163,184,.12)}
}

/* ============= 内页 Hero ============= */
header.page-hero{
  background:
    radial-gradient(900px 400px at 90% -20%,rgba(236,72,153,.20),transparent 60%),
    linear-gradient(160deg,#0b1120 0%,#141e3f 60%,#1e1b4b 100%);
  color:#e2e8f0;
  padding:130px 28px 72px;
  position:relative;overflow:hidden;
}
header.page-hero::after{
  content:'';position:absolute;inset:0;
  background-image:
    linear-gradient(rgba(255,255,255,.04) 1px,transparent 1px),
    linear-gradient(90deg,rgba(255,255,255,.04) 1px,transparent 1px);
  background-size:48px 48px;
  mask-image:radial-gradient(ellipse 80% 60% at 50% 30%,#000 30%,transparent 80%);
  -webkit-mask-image:radial-gradient(ellipse 80% 60% at 50% 30%,#000 30%,transparent 80%);
}
.ph-eyebrow{
  font-size:13px;font-weight:700;letter-spacing:3px;
  color:#a5b4fc;text-transform:uppercase;
  display:inline-flex;align-items:center;gap:8px;
}
.ph-eyebrow::before{content:'';width:24px;height:1px;background:linear-gradient(90deg,transparent,#a5b4fc)}
header.page-hero h1{
  font-size:clamp(30px,4.4vw,50px);
  font-weight:800;color:#fff;
  margin-top:14px;letter-spacing:-.6px;
  line-height:1.15;
}
header.page-hero p{
  margin-top:18px;font-size:16px;color:#94a3b8;
  max-width:680px;line-height:1.7;
}

/* ============= 通用区块 ============= */
section{padding:96px 28px}
.sec-in{max-width:1080px;margin:0 auto}
.sec-eyebrow{
  font-size:12.5px;font-weight:700;letter-spacing:2.5px;
  color:var(--blue);
  text-transform:uppercase;
  display:inline-flex;align-items:center;gap:10px;
}
.sec-eyebrow::before{content:'';width:18px;height:1.5px;background:var(--blue);border-radius:2px}
.sec-title{
  font-size:clamp(26px,3.4vw,38px);
  font-weight:800;margin-top:14px;letter-spacing:-.5px;
  color:var(--ink);
  line-height:1.2;
}
.sec-desc{
  margin-top:16px;color:var(--ink-2);
  font-size:16px;max-width:680px;line-height:1.75;
}

/* ============= 卡片通用 ============= */
.card{
  background:var(--card);
  border:1px solid var(--line);
  border-radius:var(--radius);
  padding:32px;
  transition:all .3s cubic-bezier(.4,0,.2,1);
  position:relative;
  overflow:hidden;
}
.card::before{
  content:'';position:absolute;
  top:0;left:0;right:0;height:1px;
  background:linear-gradient(90deg,transparent,rgba(124,58,237,.3),transparent);
  opacity:0;transition:opacity .3s;
}
.card:hover{
  transform:translateY(-6px);
  box-shadow:var(--shadow-lg);
  border-color:#d4daf0;
}
.card:hover::before{opacity:1}

/* ============= 网格 ============= */
.grid-2{display:grid;grid-template-columns:repeat(2,1fr);gap:24px;margin-top:48px}
.grid-3{display:grid;grid-template-columns:repeat(3,1fr);gap:20px;margin-top:48px}
.grid-4{display:grid;grid-template-columns:repeat(4,1fr);gap:18px;margin-top:48px}
@media(max-width:980px){.grid-3,.grid-4{grid-template-columns:repeat(2,1fr)}}
@media(max-width:680px){.grid-2,.grid-3,.grid-4{grid-template-columns:1fr}}

/* ============= 方向卡片 ============= */
.dir-card{
  background:var(--card);border:1px solid var(--line);
  border-radius:var(--radius);padding:32px;
  transition:all .3s cubic-bezier(.4,0,.2,1);
  position:relative;overflow:hidden;display:block;
}
.dir-card::before{
  content:'';position:absolute;top:0;left:0;right:0;height:3px;
  background:var(--grad);opacity:0;transition:opacity .3s;
}
.dir-card::after{
  content:'';position:absolute;
  top:0;right:0;width:120px;height:120px;
  background:radial-gradient(circle,rgba(124,58,237,.06) 0%,transparent 70%);
  opacity:0;transition:opacity .3s;
  pointer-events:none;
}
.dir-card:hover{transform:translateY(-6px);box-shadow:var(--shadow-lg);border-color:#d4daf0}
.dir-card:hover::before{opacity:1}
.dir-card:hover::after{opacity:1}
.dir-ic{
  width:54px;height:54px;border-radius:16px;
  background:var(--grad-soft);
  border:1px solid #e0e7ff;
  display:flex;align-items:center;justify-content:center;
  font-size:26px;margin-bottom:20px;
  position:relative;z-index:1;
}
.dir-card h3{font-size:18.5px;font-weight:700;margin-bottom:10px;position:relative;z-index:1}
.dir-card p{font-size:14.5px;color:var(--ink-2);margin-bottom:18px;line-height:1.7;position:relative;z-index:1}
.dir-tags{display:flex;flex-wrap:wrap;gap:6px;position:relative;z-index:1}
.tag{font-size:12px;color:var(--blue);background:#eff6ff;border:1px solid #dbeafe;padding:3px 10px;border-radius:999px;white-space:nowrap;font-weight:500}
.tag-violet{color:var(--violet);background:#f5f3ff;border-color:#ede9fe}

/* ============= 服务卡片 ============= */
.svc-card{
  background:var(--card);border:1px solid var(--line);
  border-radius:var(--radius);padding:28px;
  display:flex;flex-direction:column;
  transition:all .3s cubic-bezier(.4,0,.2,1);
  position:relative;overflow:hidden;
}
.svc-card::after{
  content:'';position:absolute;
  top:0;right:0;width:160px;height:160px;
  background:radial-gradient(circle,rgba(37,99,235,.06) 0%,transparent 70%);
  opacity:0;transition:opacity .3s;
  pointer-events:none;
}
.svc-card:hover{transform:translateY(-6px);box-shadow:var(--shadow-lg);border-color:#d4daf0}
.svc-card:hover::after{opacity:1}
.svc-num{
  display:inline-flex;align-items:center;gap:6px;
  font-size:11px;font-weight:800;letter-spacing:1.5px;
  color:var(--violet);text-transform:uppercase;
  background:#f5f3ff;padding:4px 10px;border-radius:999px;
  margin-bottom:14px;width:fit-content;
}
.svc-card h3{font-size:17.5px;font-weight:700;margin-bottom:10px}
.svc-card p{font-size:14px;color:var(--ink-2);flex:1;line-height:1.7}
.svc-card .svc-meta{
  margin-top:18px;font-size:12.5px;color:var(--ink-3);
  border-top:1px dashed var(--line);padding-top:14px;
  display:flex;align-items:center;gap:6px;
}
.svc-card .svc-meta::before{content:'⏱'}

/* ============= 作品卡片 ============= */
.tabs{display:flex;gap:8px;margin-top:36px;flex-wrap:wrap;background:rgba(241,243,250,.6);padding:5px;border-radius:16px;width:fit-content}
.tab{padding:10px 20px;border-radius:12px;font-size:14px;font-weight:600;color:var(--ink-2);background:transparent;border:none;cursor:pointer;transition:all .25s;font-family:inherit}
.tab:hover{color:var(--blue)}
.tab.active{background:var(--card);color:var(--ink);box-shadow:var(--shadow-sm)}
.works-panel{display:none;grid-template-columns:repeat(3,1fr);gap:18px}
.works-panel.active{display:grid;animation:fadeIn .35s ease}
@keyframes fadeIn{from{opacity:0;transform:translateY(10px)}to{opacity:1;transform:none}}
@media(max-width:980px){.works-panel.active{grid-template-columns:repeat(2,1fr)}}
@media(max-width:640px){.works-panel.active{grid-template-columns:1fr}}
.work-card{
  background:var(--card);border:1px solid var(--line);
  border-radius:16px;padding:22px;
  transition:all .25s cubic-bezier(.4,0,.2,1);
  display:block;position:relative;overflow:hidden;
}
.work-card::before{
  content:'';position:absolute;top:0;left:0;
  width:3px;height:0;background:var(--grad);
  transition:height .3s ease;
}
.work-card:hover{transform:translateY(-4px);box-shadow:var(--shadow-md);border-color:#d4daf0}
.work-card:hover::before{height:100%}
.work-badge{
  display:inline-block;font-size:10.5px;font-weight:700;
  padding:3px 10px;border-radius:999px;margin-bottom:12px;
  letter-spacing:.5px;text-transform:uppercase;
}
.badge-new{background:linear-gradient(135deg,#fef3c7,#fde68a);color:#b45309;border:1px solid #fcd34d}
.badge-book{background:#eff6ff;color:#1d4ed8;border:1px solid #dbeafe}
.badge-sys{background:#f5f3ff;color:#6d28d9;border:1px solid #ede9fe}
.badge-prod{background:#ecfdf5;color:#047857;border:1px solid #d1fae5}
.badge-research{background:#fef2f2;color:#b91c1c;border:1px solid #fee2e2}
.work-card h4{font-size:15.5px;font-weight:700;margin-bottom:8px;line-height:1.45}
.work-card p{font-size:13px;color:var(--ink-2);line-height:1.65}
.work-card .work-link{
  margin-top:14px;font-size:12.5px;color:var(--blue);
  display:inline-flex;align-items:center;gap:5px;
  opacity:.7;font-weight:600;transition:all .25s;
}
.work-card:hover .work-link{opacity:1;gap:8px}
.work-foot{margin-top:32px;font-size:13.5px;color:var(--ink-3);text-align:center}
.work-foot a{color:var(--blue);font-weight:600}

/* ============= 时间线 ============= */
.timeline{position:relative;margin-top:48px;padding-left:36px}
.timeline::before{
  content:'';position:absolute;left:8px;top:8px;bottom:8px;
  width:2px;
  background:linear-gradient(180deg,#60a5fa,#a78bfa 50%,#f0abfc);
  border-radius:2px;
}
.tl-item{position:relative;padding-bottom:36px}
.tl-item:last-child{padding-bottom:0}
.tl-item::before{
  content:'';position:absolute;left:-32px;top:6px;
  width:14px;height:14px;border-radius:50%;
  background:var(--card);border:3px solid var(--violet);
  box-shadow:0 0 0 4px rgba(124,58,237,.12);
}
.tl-year{
  display:inline-block;
  font-size:12px;font-weight:800;color:var(--blue);
  letter-spacing:1.5px;text-transform:uppercase;
  background:#eff6ff;padding:4px 12px;border-radius:999px;
}
.tl-item h4{font-size:17px;font-weight:700;margin:10px 0 8px}
.tl-item p{font-size:14.5px;color:var(--ink-2);line-height:1.7}

/* ============= FAQ ============= */
.faq{margin-top:40px;display:flex;flex-direction:column;gap:10px}
.faq-item{
  border:1px solid var(--line);
  border-radius:14px;
  background:var(--card);overflow:hidden;
  transition:all .25s;
}
.faq-item:hover{border-color:#c7d2fe}
.faq-q{
  width:100%;text-align:left;padding:18px 22px;
  font-size:15px;font-weight:600;
  background:none;border:none;cursor:pointer;
  display:flex;justify-content:space-between;align-items:center;gap:12px;
  color:var(--ink);font-family:inherit;transition:color .25s;
}
.faq-q:hover{color:var(--blue)}
.faq-q .arrow{
  width:28px;height:28px;border-radius:50%;
  background:#f1f5f9;display:flex;align-items:center;justify-content:center;
  transition:all .25s;color:var(--ink-3);flex-shrink:0;font-size:18px;
}
.faq-item.open .arrow{transform:rotate(45deg);background:var(--grad-cool);color:#fff}
.faq-a{display:none;padding:0 22px 20px;font-size:14px;color:var(--ink-2);line-height:1.75}
.faq-item.open .faq-a{display:block;animation:fadeIn .25s ease}

/* ============= 合作流程 ============= */
.steps{display:grid;grid-template-columns:repeat(4,1fr);gap:18px;margin-top:44px}
.step{
  background:var(--card);border:1px solid var(--line);
  border-radius:18px;padding:24px;position:relative;
  transition:all .25s;
}
.step:hover{transform:translateY(-4px);box-shadow:var(--shadow-md);border-color:#d4daf0}
.step-num{
  width:38px;height:38px;border-radius:12px;
  background:var(--grad-cool);color:#fff;
  font-weight:800;font-size:16px;
  display:flex;align-items:center;justify-content:center;
  margin-bottom:16px;
  box-shadow:0 6px 16px rgba(99,102,241,.3);
}
.step h4{font-size:15.5px;font-weight:700;margin-bottom:8px}
.step p{font-size:13.5px;color:var(--ink-2);line-height:1.65}
@media(max-width:980px){.steps{grid-template-columns:repeat(2,1fr)}}
@media(max-width:640px){.steps{grid-template-columns:1fr}}

/* ============= 联系 ============= */
.contact-grid{display:grid;grid-template-columns:1.1fr 1fr;gap:48px;margin-top:44px;align-items:start}
.contact-intro p{font-size:15.5px;color:var(--ink-2);margin-bottom:12px;line-height:1.75}
.contact-intro b{color:var(--ink)}
.social-grid{display:grid;grid-template-columns:repeat(2,1fr);gap:12px}
.social-card{
  display:flex;align-items:center;gap:14px;
  background:var(--card);border:1px solid var(--line);
  border-radius:16px;padding:16px 18px;
  transition:all .25s;position:relative;overflow:hidden;
}
.social-card::before{
  content:'';position:absolute;inset:0;
  background:var(--grad-card);opacity:0;transition:opacity .25s;
}
.social-card:hover{transform:translateY(-3px);border-color:#c7d2fe;box-shadow:var(--shadow-md)}
.social-card:hover::before{opacity:1}
.social-ic{
  width:42px;height:42px;border-radius:12px;
  background:var(--grad-soft);
  display:flex;align-items:center;justify-content:center;
  font-size:18px;flex-shrink:0;
  border:1px solid #e0e7ff;
  position:relative;z-index:1;
}
.social-card b{display:block;font-size:14.5px;font-weight:700;position:relative;z-index:1}
.social-card span{font-size:12px;color:var(--ink-3);position:relative;z-index:1}
.wechat-card{grid-column:1/-1;background:var(--grad-soft);border:1.5px dashed #c7d2fe}
.wechat-card:hover{background:var(--grad-soft)}
.wechat-card .social-ic{background:#fff}
@media(max-width:880px){.contact-grid{grid-template-columns:1fr}}

/* ============= 页脚 ============= */
footer{
  border-top:1px solid var(--line);
  padding:40px 28px;
  text-align:center;color:var(--ink-3);font-size:13.5px;
  background:var(--card);
  position:relative;
}
footer::before{
  content:'';position:absolute;top:-1px;left:50%;transform:translateX(-50%);
  width:120px;height:2px;
  background:var(--grad);
}
footer .foot-links{margin-bottom:14px;display:flex;gap:22px;justify-content:center;flex-wrap:wrap}
footer .foot-links a{color:var(--ink-2);font-weight:500;transition:color .25s}
footer .foot-links a:hover{color:var(--blue)}

/* ============= 正文排版 ============= */
.prose{font-size:16px;color:var(--ink-2)}
.prose p{margin-bottom:18px;line-height:1.85}
.prose b,.prose strong{color:var(--ink);font-weight:600}
.prose h3{font-size:20px;color:var(--ink);margin:32px 0 14px;font-weight:700;letter-spacing:-.3px}
.prose ul{margin:0 0 18px 22px}
.prose li{margin-bottom:10px;line-height:1.75}
.note{
  background:var(--grad-soft);
  border:1px solid #e0e7ff;
  border-radius:16px;
  padding:20px 24px;font-size:14.5px;color:var(--ink-2);
  margin:24px 0;line-height:1.8;
  position:relative;
}
.note::before{
  content:'💡';
  position:absolute;top:-14px;left:20px;
  width:32px;height:32px;border-radius:10px;
  background:var(--card);
  display:flex;align-items:center;justify-content:center;
  font-size:18px;
  box-shadow:var(--shadow-sm);
  border:1px solid var(--line);
}

/* ============= 滚动渐入 ============= */
.reveal{opacity:0;transform:translateY(24px);transition:opacity .7s cubic-bezier(.4,0,.2,1),transform .7s cubic-bezier(.4,0,.2,1)}
.reveal.visible{opacity:1;transform:none}
@media(prefers-reduced-motion:reduce){.reveal{opacity:1;transform:none;transition:none}}

/* ============= 微动效 ============= */
@keyframes float{0%,100%{transform:translateY(0)}50%{transform:translateY(-6px)}}
@keyframes blink-cursor{0%,49%{opacity:1}50%,100%{opacity:0}}

/* ============= 响应式收尾 ============= */
@media(max-width:640px){
  section{padding:64px 20px}
  .nav-in{padding:0 18px;height:58px}
  header.hero{padding:120px 22px 80px}
  header.page-hero{padding:100px 22px 56px}
  .hero-cta .btn{flex:1;justify-content:center}
}