:root{
  --bg:#f7f8fb;
  --bg-soft:#eef1f8;
  --fg:#1a1a2e;
  --muted:#5a6270;
  --card:#ffffff;
  --card-glass:rgba(255,255,255,.72);
  --accent:#ff6b6b;
  --accent2:#4d7cfe;
  --accent3:#8b5cf6;
  --line:#e6e9f0;
  --line-soft:rgba(230,233,240,.7);
  --shadow:0 6px 24px rgba(26,26,46,.08);
  --shadow-hover:0 16px 40px rgba(26,26,46,.16);
  --radius:16px;
  --radius-sm:10px;
  --grad-banner:linear-gradient(135deg,#1a1a2e 0%,#2d3561 45%,#4d3a6b 100%);
  --grad-accent:linear-gradient(135deg,#ff6b6b 0%,#8b5cf6 100%);
  --grad-soft:linear-gradient(135deg,rgba(77,124,254,.12),rgba(255,107,107,.12));
}
[data-theme="dark"]{
  --bg:#11131a;
  --bg-soft:#171a23;
  --fg:#e8ecf4;
  --muted:#9aa3b2;
  --card:#1a1d27;
  --card-glass:rgba(26,29,39,.72);
  --line:#2a2f3d;
  --line-soft:rgba(42,47,61,.7);
  --shadow:0 6px 24px rgba(0,0,0,.5);
  --shadow-hover:0 16px 40px rgba(0,0,0,.6);
  --grad-banner:linear-gradient(135deg,#0d0f16 0%,#1a1d3a 45%,#2a1f45 100%);
  --grad-soft:linear-gradient(135deg,rgba(77,124,254,.18),rgba(255,107,107,.18));
}
*{margin:0;padding:0;box-sizing:border-box}
html{scroll-behavior:smooth;-webkit-text-size-adjust:100%}
body{
  font-family:-apple-system,BlinkMacSystemFont,"Segoe UI","PingFang SC","Hiragino Sans GB","Microsoft YaHei",sans-serif;
  background:var(--bg);
  color:var(--fg);
  line-height:1.75;
  transition:background .35s ease,color .35s ease;
  overflow-x:hidden;
}
body::before{
  content:"";
  position:fixed;
  inset:0;
  pointer-events:none;
  z-index:-1;
  background:
    radial-gradient(circle at 12% 8%,rgba(77,124,254,.10),transparent 42%),
    radial-gradient(circle at 88% 14%,rgba(255,107,107,.10),transparent 40%),
    radial-gradient(circle at 50% 100%,rgba(139,92,246,.08),transparent 45%);
}
a{color:var(--accent2);text-decoration:none;transition:color .2s ease}
a:hover{text-decoration:underline}
a:focus-visible,button:focus-visible,input:focus-visible{
  outline:2px solid var(--accent2);
  outline-offset:2px;
  border-radius:6px;
}
img,svg{max-width:100%;display:block}
.container{max-width:1180px;margin:0 auto;padding:0 20px}

/* ---------- Header ---------- */
header.site-header{
  position:sticky;
  top:0;
  z-index:1000;
  background:var(--card-glass);
  -webkit-backdrop-filter:blur(18px) saturate(1.4);
  backdrop-filter:blur(18px) saturate(1.4);
  border-bottom:1px solid var(--line-soft);
  box-shadow:var(--shadow);
  transition:background .35s ease,border-color .35s ease;
}
.nav-wrap{
  display:flex;
  align-items:center;
  gap:16px;
  height:64px;
}
.logo{
  display:flex;
  align-items:center;
  gap:10px;
  font-weight:800;
  font-size:20px;
  color:var(--fg);
  letter-spacing:.5px;
  transition:transform .25s ease;
}
.logo:hover{text-decoration:none;transform:translateY(-1px)}
.logo svg{
  width:34px;
  height:34px;
  border-radius:10px;
  box-shadow:0 4px 14px rgba(255,107,107,.28);
  transition:transform .35s ease;
}
.logo:hover svg{transform:rotate(-6deg) scale(1.05)}
nav.main-nav{
  flex:1;
  display:flex;
  gap:2px;
  flex-wrap:wrap;
}
nav.main-nav a{
  position:relative;
  padding:8px 11px;
  border-radius:8px;
  color:var(--fg);
  font-size:14px;
  transition:background .2s ease,color .2s ease,transform .2s ease;
}
nav.main-nav a::after{
  content:"";
  position:absolute;
  left:11px;
  right:11px;
  bottom:4px;
  height:2px;
  border-radius:2px;
  background:var(--grad-accent);
  transform:scaleX(0);
  transform-origin:left;
  transition:transform .25s ease;
}
nav.main-nav a:hover{
  background:var(--bg-soft);
  text-decoration:none;
  transform:translateY(-1px);
}
nav.main-nav a:hover::after{transform:scaleX(1)}
.search-box{display:flex;align-items:center;gap:6px}
.search-box input{
  border:1px solid var(--line);
  background:var(--bg);
  color:var(--fg);
  padding:8px 12px;
  border-radius:8px;
  width:150px;
  font-size:13px;
  transition:width .3s ease,border-color .2s ease,box-shadow .2s ease;
}
.search-box input:focus{
  width:190px;
  border-color:var(--accent2);
  box-shadow:0 0 0 3px rgba(77,124,254,.15);
  outline:none;
}
.search-box button{
  border:none;
  background:var(--accent2);
  color:#fff;
  padding:8px 14px;
  border-radius:8px;
  cursor:pointer;
  font-size:13px;
  font-weight:600;
  transition:background .2s ease,transform .2s ease,box-shadow .2s ease;
}
.search-box button:hover{
  background:var(--accent3);
  transform:translateY(-1px);
  box-shadow:0 6px 16px rgba(139,92,246,.3);
}
.theme-toggle,.menu-toggle{
  border:1px solid var(--line);
  background:var(--bg);
  color:var(--fg);
  width:38px;
  height:38px;
  border-radius:10px;
  cursor:pointer;
  font-size:16px;
  line-height:1;
  transition:background .2s ease,transform .25s ease,border-color .2s ease;
}
.theme-toggle:hover,.menu-toggle:hover{
  background:var(--bg-soft);
  transform:rotate(12deg) scale(1.05);
}
.menu-toggle{display:none}

/* ---------- Breadcrumb ---------- */
.breadcrumb{
  font-size:13px;
  color:var(--muted);
  margin:16px 0 0;
}
.breadcrumb a{color:var(--muted)}
.breadcrumb a:hover{color:var(--accent2)}

/* ---------- Banner ---------- */
.banner{
  position:relative;
  overflow:hidden;
  background:var(--grad-banner);
  color:#fff;
  border-radius:22px;
  margin:24px auto;
  padding:56px 44px;
  min-height:340px;
  display:flex;
  align-items:center;
  box-shadow:0 20px 50px rgba(26,26,46,.28);
  isolation:isolate;
}
.banner::before{
  content:"";
  position:absolute;
  inset:-40%;
  background:
    radial-gradient(circle at 20% 30%,rgba(255,107,107,.35),transparent 38%),
    radial-gradient(circle at 80% 70%,rgba(77,124,254,.35),transparent 40%),
    radial-gradient(circle at 55% 15%,rgba(139,92,246,.28),transparent 42%);
  animation:bannerFloat 14s ease-in-out infinite alternate;
  z-index:-1;
}
.banner::after{
  content:"";
  position:absolute;
  inset:0;
  background:linear-gradient(180deg,rgba(255,255,255,.06),transparent 55%);
  pointer-events:none;
  z-index:-1;
}
@keyframes bannerFloat{
  0%{transform:translate3d(-3%,-2%,0) scale(1)}
  100%{transform:translate3d(3%,2%,0) scale(1.08)}
}
.slide{display:none;animation:fade .6s ease}
.slide.active{display:block}
@keyframes fade{
  from{opacity:0;transform:translateY(14px)}
  to{opacity:1;transform:none}
}
.banner h1{
  font-size:34px;
  line-height:1.35;
  margin-bottom:14px;
  letter-spacing:.5px;
  text-shadow:0 2px 20px rgba(0,0,0,.25);
}
.banner p{
  font-size:16px;
  color:#c9d1e6;
  max-width:720px;
}
.banner .cta{
  display:inline-block;
  margin-top:24px;
  background:var(--grad-accent);
  color:#fff;
  padding:12px 28px;
  border-radius:12px;
  font-weight:600;
  box-shadow:0 10px 26px rgba(255,107,107,.35);
  transition:transform .25s ease,box-shadow .25s ease,filter .25s ease;
}
.banner .cta:hover{
  text-decoration:none;
  transform:translateY(-3px) scale(1.02);
  box-shadow:0 16px 36px rgba(139,92,246,.45);
  filter:brightness(1.06);
}
.dots{
  position:absolute;
  bottom:20px;
  right:32px;
  display:flex;
  gap:9px;
  z-index:2;
}
.dots span{
  width:9px;
  height:9px;
  border-radius:50%;
  background:rgba(255,255,255,.35);
  cursor:pointer;
  transition:background .25s ease,transform .25s ease,width .25s ease;
}
.dots span:hover{transform:scale(1.3)}
.dots span.active{
  background:var(--accent);
  width:22px;
  border-radius:6px;
}

/* ---------- Sections ---------- */
section.block{margin:48px 0}
section.block h2{
  font-size:26px;
  margin-bottom:8px;
  position:relative;
  padding-left:16px;
  letter-spacing:.3px;
}
section.block h2::before{
  content:"";
  position:absolute;
  left:0;
  top:6px;
  bottom:6px;
  width:5px;
  border-radius:3px;
  background:var(--grad-accent);
  box-shadow:0 0 12px rgba(255,107,107,.35);
}
section.block .lead{
  color:var(--muted);
  margin-bottom:24px;
  font-size:15px;
}
h3{font-size:20px;margin:24px 0 10px;letter-spacing:.2px}
h4{font-size:16px;margin:16px 0 8px;color:var(--accent2)}
p{margin-bottom:14px;color:var(--fg)}

/* ---------- Grid & Cards ---------- */
.grid{display:grid;gap:20px}
.grid-3{grid-template-columns:repeat(3,1fr)}
.grid-2{grid-template-columns:repeat(2,1fr)}
.card{
  background:var(--card);
  border:1px solid var(--line);
  border-radius:var(--radius);
  padding:22px;
  box-shadow:var(--shadow);
  transition:transform .3s cubic-bezier(.2,.8,.3,1),box-shadow .3s ease,border-color .3s ease;
  position:relative;
  overflow:hidden;
}
.card::before{
  content:"";
  position:absolute;
  inset:0;
  background:var(--grad-soft);
  opacity:0;
  transition:opacity .3s ease;
  pointer-events:none;
}
.card:hover{
  transform:translateY(-6px);
  box-shadow:var(--shadow-hover);
  border-color:rgba(77,124,254,.35);
}
.card:hover::before{opacity:1}
.card > *{position:relative;z-index:1}
.card svg{
  width:100%;
  height:150px;
  border-radius:var(--radius-sm);
  margin-bottom:14px;
  transition:transform .35s ease;
}
.card:hover svg{transform:scale(1.03)}

/* ---------- Stats ---------- */
.stats{
  display:grid;
  grid-template-columns:repeat(4,1fr);
  gap:20px;
  margin:28px 0;
}
.stat{
  background:var(--card-glass);
  -webkit-backdrop-filter:blur(14px) saturate(1.3);
  backdrop-filter:blur(14px) saturate(1.3);
  border:1px solid var(--line);
  border-radius:var(--radius);
  padding:24px 18px;
  text-align:center;
  box-shadow:var(--shadow);
  transition:transform .3s ease,box-shadow .3s ease,border-color .3s ease;
}
.stat:hover{
  transform:translateY(-4px);
  box-shadow:var(--shadow-hover);
  border-color:rgba(255,107,107,.4);
}
.stat .num{
  font-size:32px;
  font-weight:800;
  background:var(--grad-accent);
  -webkit-background-clip:text;
  background-clip:text;
  color:transparent;
  line-height:1.2;
}
.stat .label{font-size:13px;color:var(--muted);margin-top:4px}

/* ---------- Article cards ---------- */
.article-card{
  background:var(--card);
  border:1px solid var(--line);
  border-radius:var(--radius);
  padding:22px;
  display:flex;
  flex-direction:column;
  gap:8px;
  box-shadow:var(--shadow);
  transition:transform .3s cubic-bezier(.2,.8,.3,1),box-shadow .3s ease,border-color .3s ease;
}
.article-card:hover{
  transform:translateY(-5px);
  box-shadow:var(--shadow-hover);
  border-color:rgba(139,92,246,.35);
}
.article-card h3{
  font-size:17px;
  margin:0;
  line-height:1.5;
  transition:color .2s ease;
}
.article-card:hover h3{color:var(--accent2)}
.article-meta{
  font-size:12px;
  color:var(--muted);
  display:flex;
  gap:12px;
  flex-wrap:wrap;
}
.article-card p{
  font-size:14px;
  color:var(--muted);
  margin:0;
}
.read-more{
  font-size:13px;
  font-weight:600;
  margin-top:auto;
  color:var(--accent2);
  transition:transform .2s ease,color .2s ease;
  display:inline-block;
}
.read-more:hover{
  text-decoration:none;
  color:var(--accent);
  transform:translateX(4px);
}

/* ---------- FAQ ---------- */
.faq-item{
  border:1px solid var(--line);
  border-radius:12px;
  background:var(--card);
  margin-bottom:10px;
  overflow:hidden;
  transition:border-color .25s ease,box-shadow .25s ease;
}
.faq-item:hover{border-color:rgba(77,124,254,.35)}
.faq-item.open{
  border-color:rgba(255,107,107,.4);
  box-shadow:0 8px 24px rgba(255,107,107,.10);
}
.faq-q{
  width:100%;
  text-align:left;
  background:none;
  border:none;
  padding:16px 18px;
  font-size:15px;
  font-weight:600;
  color:var(--fg);
  cursor:pointer;
  display:flex;
  justify-content:space-between;
  align-items:center;
  gap:10px;
  font-family:inherit;
  transition:background .2s ease,color .2s ease;
}
.faq-q:hover{background:var(--bg-soft)}
.faq-q::after{
  content:"+";
  color:var(--accent);
  font-size:20px;
  font-weight:700;
  line-height:1;
  transition:transform .3s ease;
  flex-shrink:0;
}
.faq-item.open .faq-q::after{content:"−";transform:rotate(180deg)}
.faq-a{
  display:none;
  padding:0 18px 16px;
  color:var(--muted);
  font-size:14px;
  animation:fade .35s ease;
}
.faq-item.open .faq-a{display:block}

/* ---------- Lists ---------- */
ol.howto,ul.plain{padding-left:22px;margin-bottom:14px}
ol.howto li,ul.plain li{
  margin-bottom:8px;
  color:var(--fg);
  transition:color .2s ease,transform .2s ease;
}
ol.howto li:hover,ul.plain li:hover{
  color:var(--accent2);
  transform:translateX(3px);
}
ul.plain li a{color:var(--accent2)}

/* ---------- Contact ---------- */
.contact-grid{
  display:grid;
  grid-template-columns:repeat(2,1fr);
  gap:16px;
}
.contact-item{
  background:var(--card-glass);
  -webkit-backdrop-filter:blur(12px);
  backdrop-filter:blur(12px);
  border:1px solid var(--line);
  border-radius:12px;
  padding:16px;
  transition:transform .25s ease,border-color .25s ease,box-shadow .25s ease;
}
.contact-item:hover{
  transform:translateY(-3px);
  border-color:rgba(77,124,254,.4);
  box-shadow:var(--shadow);
}
.contact-item strong{
  display:block;
  font-size:13px;
  color:var(--muted);
  margin-bottom:4px;
  font-weight:600;
}

/* ---------- Blockquote ---------- */
blockquote.card{
  margin:14px 0;
  border-left:4px solid var(--accent);
  font-style:normal;
}
blockquote.card p{margin:0;color:var(--muted);font-size:14px}

/* ---------- Footer ---------- */
footer.site-footer{
  background:var(--card-glass);
  -webkit-backdrop-filter:blur(16px) saturate(1.3);
  backdrop-filter:blur(16px) saturate(1.3);
  border-top:1px solid var(--line);
  margin-top:52px;
  padding:44px 0 22px;
  font-size:14px;
  color:var(--muted);
}
.footer-grid{
  display:grid;
  grid-template-columns:2fr 1fr 1fr 1fr;
  gap:28px;
}
footer h4{
  color:var(--fg);
  font-size:15px;
  margin-bottom:12px;
  position:relative;
  padding-left:10px;
}
footer h4::before{
  content:"";
  position:absolute;
  left:0;
  top:5px;
  bottom:5px;
  width:3px;
  border-radius:2px;
  background:var(--grad-accent);
}
footer ul{list-style:none}
footer ul li{margin-bottom:8px;transition:transform .2s ease}
footer ul li:hover{transform:translateX(3px)}
footer a{color:var(--muted);transition:color .2s ease}
footer a:hover{color:var(--accent2);text-decoration:none}
footer p{color:var(--muted);font-size:13px;margin-bottom:10px}
.footer-bottom{
  border-top:1px solid var(--line);
  margin-top:28px;
  padding-top:18px;
  text-align:center;
  font-size:13px;
  color:var(--muted);
}
.footer-bottom p{margin-bottom:6px;font-size:12.5px}

/* ---------- Back to top ---------- */
#backToTop{
  position:fixed;
  right:24px;
  bottom:24px;
  width:46px;
  height:46px;
  border-radius:50%;
  background:var(--grad-accent);
  color:#fff;
  border:none;
  font-size:20px;
  cursor:pointer;
  display:none;
  box-shadow:0 8px 24px rgba(255,107,107,.4);
  z-index:999;
  transition:transform .25s ease,box-shadow .25s ease,filter .25s ease;
}
#backToTop:hover{
  transform:translateY(-4px) scale(1.06);
  box-shadow:0 14px 32px rgba(139,92,246,.5);
  filter:brightness(1.08);
}

/* ---------- Reveal ---------- */
.reveal{
  opacity:0;
  transform:translateY(24px);
  transition:opacity .7s cubic-bezier(.2,.8,.3,1),transform .7s cubic-bezier(.2,.8,.3,1);
  will-change:opacity,transform;
}
.reveal.visible{opacity:1;transform:none}

/* ---------- Responsive ---------- */
@media(max-width:900px){
  .grid-3{grid-template-columns:1fr 1fr}
  .stats{grid-template-columns:1fr 1fr}
  .footer-grid{grid-template-columns:1fr 1fr}
  .contact-grid{grid-template-columns:1fr}
  .banner{padding:44px 30px;min-height:300px}
  .banner h1{font-size:28px}
  nav.main-nav a{padding:7px 9px;font-size:13px}
  .search-box input{width:120px}
  .search-box input:focus{width:150px}
}
@media(max-width:640px){
  .grid-3,.grid-2{grid-template-columns:1fr}
  .stats{grid-template-columns:1fr 1fr;gap:14px}
  .stat{padding:18px 12px}
  .stat .num{font-size:26px}
  .nav-wrap{
    height:auto;
    padding:12px 0;
    flex-wrap:wrap;
    gap:10px;
  }
  .logo{font-size:18px}
  .main-nav{
    display:none;
    width:100%;
    flex-direction:column;
    gap:2px;
    padding:8px 0 4px;
    border-top:1px solid var(--line);
    margin-top:4px;
  }
  .main-nav.open{display:flex;animation:fade .3s ease}
  .main-nav a{padding:10px 12px}
  .menu-toggle{display:block;order:3}
  .search-box{order:4;flex:1;min-width:0}
  .search-box input{width:100%;flex:1}
  .search-box input:focus{width:100%}
  .theme-toggle{order:2;margin-left:auto}
  .banner{padding:36px 22px;border-radius:18px;min-height:280px;margin:18px auto}
  .banner h1{font-size:23px;line-height:1.4}
  .banner p{font-size:14px}
  .banner .cta{padding:10px 22px;font-size:14px}
  .dots{right:20px;bottom:16px}
  section.block{margin:36px 0}
  section.block h2{font-size:22px}
  h3{font-size:18px}
  .footer-grid{grid-template-columns:1fr;gap:22px}
  #backToTop{right:16px;bottom:16px;width:42px;height:42px}
  .card,.article-card{padding:18px}
  .contact-grid{gap:12px}
}
@media(max-width:380px){
  .stats{grid-template-columns:1fr}
  .banner h1{font-size:20px}
}

/* ---------- Motion & Print ---------- */
@media(prefers-reduced-motion:reduce){
  *,*::before,*::after{
    animation-duration:.001ms !important;
    animation-iteration-count:1 !important;
    transition-duration:.001ms !important;
    scroll-behavior:auto !important;
  }
  .reveal{opacity:1;transform:none}
}
@media print{
  header.site-header,#backToTop,.banner,.dots,.search-box,.theme-toggle,.menu-toggle{display:none !important}
  body{background:#fff;color:#000}
  .card,.article-card,.stat,.contact-item{box-shadow:none;border:1px solid #ccc}
  a{color:#000;text-decoration:underline}
}