:root{
  --brand:#1f6feb;
  --brand-2:#ff7a18;
  --brand-3:#7c5cff;
  --bg:#f7f9fc;
  --bg-2:#eef3fb;
  --text:#1f2328;
  --muted:#5b6573;
  --card:#ffffff;
  --card-glass:rgba(255,255,255,.72);
  --line:#e5e9f0;
  --line-soft:rgba(31,111,235,.12);
  --shadow:0 8px 24px rgba(18,38,63,.08);
  --shadow-lg:0 20px 48px rgba(18,38,63,.14);
  --shadow-glow:0 10px 30px rgba(31,111,235,.28);
  --radius-sm:10px;
  --radius:16px;
  --radius-lg:22px;
  --radius-pill:999px;
  --header-h:72px;
  --ease:cubic-bezier(.22,.61,.36,1);
  --grad-hero:linear-gradient(135deg,#1f6feb 0%,#7c5cff 45%,#ff7a18 100%);
  --grad-brand:linear-gradient(135deg,#1f6feb,#7c5cff);
  --grad-warm:linear-gradient(135deg,#ff7a18,#ffb457);
  --grad-soft:linear-gradient(135deg,rgba(31,111,235,.12),rgba(255,122,24,.12));
  --grad-line:linear-gradient(90deg,rgba(31,111,235,0),rgba(31,111,235,.5),rgba(255,122,24,.5),rgba(255,122,24,0));
}

html[data-theme="dark"]{
  --brand:#5b9bff;
  --brand-2:#ff9a4d;
  --brand-3:#a58bff;
  --bg:#0d1117;
  --bg-2:#111823;
  --text:#e6edf3;
  --muted:#9aa7b6;
  --card:#161d27;
  --card-glass:rgba(22,29,39,.72);
  --line:#232c38;
  --line-soft:rgba(91,155,255,.18);
  --shadow:0 8px 24px rgba(0,0,0,.45);
  --shadow-lg:0 20px 48px rgba(0,0,0,.55);
  --shadow-glow:0 10px 30px rgba(91,155,255,.3);
  --grad-hero:linear-gradient(135deg,#1b3a6b 0%,#3a2a6b 45%,#6b3a1b 100%);
  --grad-brand:linear-gradient(135deg,#5b9bff,#a58bff);
  --grad-warm:linear-gradient(135deg,#ff9a4d,#ffc078);
  --grad-soft:linear-gradient(135deg,rgba(91,155,255,.14),rgba(255,154,77,.14));
}

*{box-sizing:border-box}

html{
  scroll-behavior:smooth;
  -webkit-text-size-adjust:100%;
  scroll-padding-top:calc(var(--header-h) + 12px);
}

body{
  margin:0;
  font-family:-apple-system,BlinkMacSystemFont,"Segoe UI","Microsoft YaHei","PingFang SC","Hiragino Sans GB",sans-serif;
  color:var(--text);
  background:var(--bg);
  line-height:1.8;
  font-size:16px;
  overflow-x:hidden;
  transition:background-color .4s var(--ease),color .4s var(--ease);
  -webkit-font-smoothing:antialiased;
  -moz-osx-font-smoothing:grayscale;
}

body::before{
  content:"";
  position:fixed;
  inset:0;
  pointer-events:none;
  z-index:0;
  background:
    radial-gradient(600px 300px at 8% -5%,rgba(31,111,235,.10),transparent 65%),
    radial-gradient(520px 280px at 95% 8%,rgba(255,122,24,.10),transparent 65%),
    radial-gradient(500px 300px at 50% 110%,rgba(124,92,255,.08),transparent 65%);
}

html[data-theme="dark"] body::before{
  background:
    radial-gradient(600px 300px at 8% -5%,rgba(91,155,255,.14),transparent 65%),
    radial-gradient(520px 280px at 95% 8%,rgba(255,154,77,.12),transparent 65%),
    radial-gradient(500px 300px at 50% 110%,rgba(165,139,255,.12),transparent 65%);
}

main,header,footer{position:relative;z-index:1}

a{
  color:var(--brand);
  text-decoration:none;
  transition:color .25s var(--ease),opacity .25s var(--ease);
}

a:hover{
  color:var(--brand-2);
  text-decoration:none;
}

img,svg{max-width:100%;display:block}

h1,h2,h3,h4{
  line-height:1.3;
  letter-spacing:-.01em;
  color:var(--text);
}

p{margin:0 0 12px}

ul,ol{padding-left:1.3em;margin:0 0 12px}
li{margin-bottom:6px;color:var(--muted)}

.container{
  width:min(1180px,92%);
  margin:0 auto;
}

/* ===== Header ===== */
.header{
  position:sticky;
  top:0;
  z-index:50;
  background:var(--card-glass);
  -webkit-backdrop-filter:blur(16px) saturate(180%);
  backdrop-filter:blur(16px) saturate(180%);
  border-bottom:1px solid var(--line);
  box-shadow:0 1px 0 rgba(255,255,255,.4) inset;
  transition:background-color .4s var(--ease),border-color .4s var(--ease);
}

html[data-theme="dark"] .header{
  box-shadow:0 1px 0 rgba(255,255,255,.04) inset;
}

.nav{
  display:flex;
  align-items:center;
  justify-content:space-between;
  padding:14px 0;
  gap:16px;
  min-height:var(--header-h);
}

.logo{
  display:flex;
  align-items:center;
  gap:10px;
  font-weight:800;
  font-size:20px;
  color:var(--text);
  letter-spacing:-.02em;
  transition:transform .3s var(--ease);
}

.logo:hover{
  color:var(--text);
  transform:translateY(-1px);
}

.logo-mark{
  width:38px;
  height:38px;
  border-radius:12px;
  background:var(--grad-hero);
  background-size:200% 200%;
  display:grid;
  place-items:center;
  color:#fff;
  font-weight:900;
  font-size:15px;
  box-shadow:var(--shadow-glow);
  transition:transform .4s var(--ease),box-shadow .4s var(--ease);
  animation:gradShift 8s ease infinite;
}

.logo:hover .logo-mark{
  transform:rotate(-6deg) scale(1.06);
  box-shadow:0 12px 34px rgba(124,92,255,.4);
}

@keyframes gradShift{
  0%,100%{background-position:0% 50%}
  50%{background-position:100% 50%}
}

.nav-links{
  display:flex;
  gap:6px;
  flex-wrap:wrap;
  align-items:center;
}

.nav-links a{
  color:var(--muted);
  font-size:15px;
  font-weight:500;
  padding:8px 12px;
  border-radius:var(--radius-pill);
  position:relative;
  transition:color .25s var(--ease),background-color .25s var(--ease),transform .25s var(--ease);
}

.nav-links a::after{
  content:"";
  position:absolute;
  left:50%;
  bottom:4px;
  width:0;
  height:2px;
  border-radius:2px;
  background:var(--grad-brand);
  transform:translateX(-50%);
  transition:width .3s var(--ease);
}

.nav-links a:hover{
  color:var(--brand);
  background:var(--line-soft);
  transform:translateY(-1px);
}

.nav-links a:hover::after{width:40%}

.nav-actions{
  display:flex;
  gap:10px;
  align-items:center;
}

.btn{
  display:inline-block;
  padding:10px 16px;
  border-radius:var(--radius-sm);
  border:1px solid var(--line);
  background:var(--card);
  color:var(--text);
  font-weight:600;
  font-size:14px;
  font-family:inherit;
  cursor:pointer;
  white-space:nowrap;
  transition:transform .25s var(--ease),box-shadow .25s var(--ease),background-color .25s var(--ease),border-color .25s var(--ease),color .25s var(--ease);
}

.btn:hover{
  transform:translateY(-2px);
  box-shadow:var(--shadow);
  border-color:var(--brand);
  color:var(--brand);
}

.btn:active{transform:translateY(0) scale(.98)}

.btn.primary{
  background:var(--grad-brand);
  background-size:180% 180%;
  border-color:transparent;
  color:#fff;
  box-shadow:var(--shadow-glow);
}

.btn.primary:hover{
  color:#fff;
  box-shadow:0 14px 34px rgba(31,111,235,.42);
  transform:translateY(-2px);
}

.breadcrumb{
  font-size:13px;
  color:var(--muted);
  padding:0 0 12px;
  opacity:.9;
}

.breadcrumb a{color:var(--muted)}
.breadcrumb a:hover{color:var(--brand)}

/* ===== Hero ===== */
.hero{
  position:relative;
  padding:52px 0 40px;
  overflow:hidden;
}

.hero::before{
  content:"";
  position:absolute;
  inset:0;
  background:
    radial-gradient(900px 420px at 8% 0%,rgba(31,111,235,.16),transparent 62%),
    radial-gradient(760px 380px at 92% 6%,rgba(255,122,24,.15),transparent 62%),
    radial-gradient(600px 320px at 50% 100%,rgba(124,92,255,.10),transparent 65%);
  pointer-events:none;
}

html[data-theme="dark"] .hero::before{
  background:
    radial-gradient(900px 420px at 8% 0%,rgba(91,155,255,.20),transparent 62%),
    radial-gradient(760px 380px at 92% 6%,rgba(255,154,77,.16),transparent 62%),
    radial-gradient(600px 320px at 50% 100%,rgba(165,139,255,.16),transparent 65%);
}

.hero::after{
  content:"";
  position:absolute;
  left:0;
  right:0;
  bottom:0;
  height:1px;
  background:var(--grad-line);
  opacity:.7;
}

.hero-grid{
  position:relative;
  display:grid;
  grid-template-columns:1.3fr .7fr;
  gap:32px;
  align-items:center;
}

.hero h1{
  font-size:clamp(28px,4.2vw,44px);
  line-height:1.22;
  margin:0 0 16px;
  font-weight:800;
  background:linear-gradient(120deg,var(--text) 0%,var(--text) 55%,var(--brand) 100%);
  -webkit-background-clip:text;
  background-clip:text;
  -webkit-text-fill-color:transparent;
  animation:fadeUp .8s var(--ease) both;
}

html[data-theme="dark"] .hero h1{
  background:linear-gradient(120deg,#e6edf3 0%,#e6edf3 55%,var(--brand) 100%);
  -webkit-background-clip:text;
  background-clip:text;
}

.hero p{
  color:var(--muted);
  font-size:16.5px;
  margin:0 0 16px;
  max-width:62ch;
  animation:fadeUp .8s var(--ease) both;
  animation-delay:.08s;
}

.badge{
  display:inline-flex;
  align-items:center;
  gap:8px;
  padding:7px 14px;
  border-radius:var(--radius-pill);
  background:var(--card-glass);
  -webkit-backdrop-filter:blur(10px);
  backdrop-filter:blur(10px);
  border:1px solid var(--line-soft);
  color:var(--brand);
  font-weight:700;
  font-size:12.5px;
  letter-spacing:.02em;
  margin-bottom:16px;
  box-shadow:var(--shadow);
  animation:fadeUp .7s var(--ease) both;
}

.badge::before{
  content:"";
  width:7px;
  height:7px;
  border-radius:50%;
  background:var(--grad-warm);
  box-shadow:0 0 0 4px rgba(255,122,24,.18);
  animation:pulse 2.2s ease infinite;
}

@keyframes pulse{
  0%,100%{opacity:1;transform:scale(1)}
  50%{opacity:.6;transform:scale(.82)}
}

.hero-card{
  position:relative;
  background:var(--card-glass);
  -webkit-backdrop-filter:blur(18px) saturate(160%);
  backdrop-filter:blur(18px) saturate(160%);
  border:1px solid var(--line);
  border-radius:var(--radius-lg);
  padding:22px;
  box-shadow:var(--shadow-lg);
  overflow:hidden;
  transition:transform .45s var(--ease),box-shadow .45s var(--ease),border-color .45s var(--ease);
  animation:fadeUp .9s var(--ease) both;
  animation-delay:.15s;
}

.hero-card::before{
  content:"";
  position:absolute;
  inset:0 0 auto 0;
  height:3px;
  background:var(--grad-hero);
  background-size:200% 100%;
  animation:gradShift 6s linear infinite;
}

.hero-card:hover{
  transform:translateY(-6px);
  box-shadow:0 28px 60px rgba(18,38,63,.18);
  border-color:var(--line-soft);
}

.hero-card h2{
  font-size:18px;
  margin:0 0 10px;
}

.hero-card a{
  display:inline-flex;
  align-items:center;
  font-size:14.5px;
  font-weight:600;
  padding:9px 12px;
  border-radius:var(--radius-sm);
  background:rgba(31,111,235,.06);
  border:1px solid transparent;
  transition:transform .25s var(--ease),background-color .25s var(--ease),border-color .25s var(--ease),box-shadow .25s var(--ease);
}

html[data-theme="dark"] .hero-card a{background:rgba(91,155,255,.10)}

.hero-card a:hover{
  transform:translateX(4px);
  background:rgba(31,111,235,.12);
  border-color:var(--line-soft);
  box-shadow:var(--shadow);
}

.stats{
  display:grid;
  grid-template-columns:repeat(3,1fr);
  gap:12px;
  margin-top:18px;
}

.stat{
  position:relative;
  background:var(--card-glass);
  -webkit-backdrop-filter:blur(10px);
  backdrop-filter:blur(10px);
  border:1px solid var(--line);
  border-radius:var(--radius);
  padding:16px 12px;
  text-align:center;
  transition:transform .35s var(--ease),box-shadow .35s var(--ease),border-color .35s var(--ease);
}

.stat:hover{
  transform:translateY(-4px);
  box-shadow:var(--shadow);
  border-color:var(--line-soft);
}

.stat strong{
  display:block;
  font-size:24px;
  font-weight:800;
  background:var(--grad-brand);
  -webkit-background-clip:text;
  background-clip:text;
  -webkit-text-fill-color:transparent;
  letter-spacing:-.02em;
}

.stat span{
  font-size:12.5px;
  color:var(--muted);
}

/* ===== Sections ===== */
.section{
  padding:44px 0;
  position:relative;
}

.section h2{
  font-size:clamp(22px,2.6vw,30px);
  margin:0 0 10px;
  font-weight:800;
  position:relative;
  display:inline-block;
  padding-bottom:8px;
}

.section h2::after{
  content:"";
  position:absolute;
  left:0;
  bottom:0;
  width:64px;
  height:4px;
  border-radius:4px;
  background:var(--grad-hero);
  background-size:200% 100%;
  animation:gradShift 5s linear infinite;
}

.section .lead{
  color:var(--muted);
  margin:0 0 24px;
  font-size:16px;
  max-width:80ch;
}

/* ===== Grid & Cards ===== */
.grid{display:grid;gap:18px}
.grid-3{grid-template-columns:repeat(3,1fr)}
.grid-2{grid-template-columns:repeat(2,1fr)}

.card{
  position:relative;
  background:var(--card);
  border:1px solid var(--line);
  border-radius:var(--radius);
  padding:20px;
  box-shadow:var(--shadow);
  overflow:hidden;
  transition:transform .4s var(--ease),box-shadow .4s var(--ease),border-color .4s var(--ease),background-color .4s var(--ease);
}

.card::before{
  content:"";
  position:absolute;
  inset:0;
  border-radius:inherit;
  padding:1px;
  background:var(--grad-hero);
  -webkit-mask:linear-gradient(#000 0 0) content-box,linear-gradient(#000 0 0);
  -webkit-mask-composite:xor;
  mask:linear-gradient(#000 0 0) content-box,linear-gradient(#000 0 0);
  mask-composite:exclude;
  opacity:0;
  transition:opacity .4s var(--ease);
  pointer-events:none;
}

.card::after{
  content:"";
  position:absolute;
  top:-60%;
  right:-30%;
  width:200px;
  height:200px;
  border-radius:50%;
  background:radial-gradient(circle,rgba(31,111,235,.10),transparent 70%);
  opacity:0;
  transition:opacity .5s var(--ease),transform .5s var(--ease);
  pointer-events:none;
}

.card:hover{
  transform:translateY(-6px);
  box-shadow:var(--shadow-lg);
  border-color:transparent;
}

.card:hover::before{opacity:1}
.card:hover::after{opacity:1;transform:translate(-14px,14px)}

.card h3{
  margin:0 0 8px;
  font-size:18px;
  font-weight:700;
}

.card p{
  margin:0 0 8px;
  color:var(--muted);
  font-size:15px;
}

.card p:last-child{margin-bottom:0}

.card ul{padding-left:1.15em}
.card li{font-size:14.5px}

.tag{
  display:inline-block;
  font-size:12px;
  padding:4px 10px;
  border-radius:var(--radius-pill);
  background:linear-gradient(135deg,rgba(31,111,235,.12),rgba(124,92,255,.12));
  color:var(--brand);
  font-weight:700;
  letter-spacing:.02em;
  margin-bottom:10px;
  border:1px solid var(--line-soft);
  transition:transform .3s var(--ease),box-shadow .3s var(--ease);
}

.card:hover .tag{
  transform:translateY(-1px);
  box-shadow:0 6px 16px rgba(31,111,235,.18);
}

html[data-theme="dark"] .tag{
  background:linear-gradient(135deg,rgba(91,155,255,.16),rgba(165,139,255,.16));
}

/* ===== Article List ===== */
.article-list{display:grid;gap:14px}

.article-item{
  display:grid;
  grid-template-columns:120px 1fr;
  gap:16px;
  align-items:start;
  background:var(--card);
  border:1px solid var(--line);
  border-radius:var(--radius);
  padding:14px;
  box-shadow:var(--shadow);
  transition:transform .35s var(--ease),box-shadow .35s var(--ease),border-color .35s var(--ease);
  position:relative;
  overflow:hidden;
}

.article-item::before{
  content:"";
  position:absolute;
  left:0;
  top:0;
  bottom:0;
  width:3px;
  background:var(--grad-brand);
  transform:scaleY(0);
  transform-origin:top;
  transition:transform .4s var(--ease);
}

.article-item:hover{
  transform:translateX(6px);
  box-shadow:var(--shadow-lg);
  border-color:var(--line-soft);
}

.article-item:hover::before{transform:scaleY(1)}

.article-thumb{
  width:120px;
  height:84px;
  border-radius:12px;
  overflow:hidden;
  background:var(--bg-2);
  flex-shrink:0;
  transition:transform .45s var(--ease),box-shadow .45s var(--ease);
}

.article-item:hover .article-thumb{
  transform:scale(1.04);
  box-shadow:var(--shadow);
}

.article-thumb svg{
  width:100%;
  height:100%;
  transition:transform .5s var(--ease);
}

.article-item:hover .article-thumb svg{transform:scale(1.08)}

.article-item h3{
  margin:0 0 6px;
  font-size:17px;
  font-weight:700;
  transition:color .3s var(--ease);
}

.article-item:hover h3{color:var(--brand)}

.article-item a{
  font-weight:600;
  font-size:14px;
  display:inline-block;
  transition:transform .3s var(--ease);
}

.article-item a:hover{transform:translateX(4px)}

.meta{
  color:var(--muted);
  font-size:13px;
  margin:0 0 6px;
}

/* ===== FAQ ===== */
.faq-item{
  border:1px solid var(--line);
  border-radius:var(--radius);
  background:var(--card);
  margin-bottom:12px;
  overflow:hidden;
  box-shadow:var(--shadow);
  transition:box-shadow .35s var(--ease),border-color .35s var(--ease),transform .35s var(--ease);
}

.faq-item:hover{
  box-shadow:var(--shadow-lg);
  border-color:var(--line-soft);
}

.faq-item.open{
  border-color:var(--line-soft);
  box-shadow:var(--shadow-lg);
}

.faq-q{
  width:100%;
  text-align:left;
  padding:16px 48px 16px 18px;
  background:transparent;
  border:0;
  font-weight:700;
  font-size:16px;
  font-family:inherit;
  color:var(--text);
  cursor:pointer;
  position:relative;
  line-height:1.6;
  transition:color .3s var(--ease),background-color .3s var(--ease);
}

.faq-q::after{
  content:"+";
  position:absolute;
  right:18px;
  top:50%;
  transform:translateY(-50%);
  width:26px;
  height:26px;
  border-radius:50%;
  display:grid;
  place-items:center;
  font-size:18px;
  font-weight:600;
  color:var(--brand);
  background:rgba(31,111,235,.10);
  transition:transform .4s var(--ease),background-color .4s var(--ease),color .4s var(--ease);
}

html[data-theme="dark"] .faq-q::after{background:rgba(91,155,255,.16)}

.faq-q:hover{
  color:var(--brand);
  background:rgba(31,111,235,.04);
}

.faq-item.open .faq-q{color:var(--brand)}

.faq-item.open .faq-q::after{
  content:"−";
  transform:translateY(-50%) rotate(180deg);
  background:var(--grad-brand);
  color:#fff;
}

.faq-a{
  padding:0 18px 18px;
  color:var(--muted);
  display:none;
  font-size:15px;
  animation:fadeDown .4s var(--ease) both;
}

.faq-item.open .faq-a{display:block}

@keyframes fadeDown{
  from{opacity:0;transform:translateY(-8px)}
  to{opacity:1;transform:translateY(0)}
}

/* ===== HowTo ===== */
#howto ol{
  counter-reset:step;
  list-style:none;
  padding-left:0;
  margin:0;
}

#howto ol li{
  position:relative;
  counter-increment:step;
  padding:12px 12px 12px 52px;
  margin-bottom:10px;
  border-radius:var(--radius-sm);
  background:rgba(31,111,235,.04);
  border:1px solid transparent;
  color:var(--text);
  font-size:15px;
  transition:transform .3s var(--ease),background-color .3s var(--ease),border-color .3s var(--ease),box-shadow .3s var(--ease);
}

html[data-theme="dark"] #howto ol li{background:rgba(91,155,255,.07)}

#howto ol li::before{
  content:counter(step);
  position:absolute;
  left:12px;
  top:50%;
  transform:translateY(-50%);
  width:28px;
  height:28px;
  border-radius:50%;
  display:grid;
  place-items:center;
  font-size:13px;
  font-weight:800;
  color:#fff;
  background:var(--grad-brand);
  box-shadow:0 6px 14px rgba(31,111,235,.3);
}

#howto ol li:hover{
  transform:translateX(6px);
  background:rgba(31,111,235,.09);
  border-color:var(--line-soft);
  box-shadow:var(--shadow);
}

/* ===== Footer ===== */
.footer{
  position:relative;
  background:linear-gradient(160deg,#0f172a 0%,#131c33 50%,#0b1120 100%);
  color:#cbd5e1;
  padding:44px 0 30px;
  margin-top:40px;
  overflow:hidden;
}

.footer::before{
  content:"";
  position:absolute;
  top:0;
  left:0;
  right:0;
  height:1px;
  background:var(--grad-line);
  opacity:.6;
}

.footer::after{
  content:"";
  position:absolute;
  top:-120px;
  right:-80px;
  width:360px;
  height:360px;
  border-radius:50%;
  background:radial-gradient(circle,rgba(31,111,235,.18),transparent 70%);
  pointer-events:none;
}

.footer a{
  color:#e2e8f0;
  transition:color .25s var(--ease),transform .25s var(--ease);
  display:inline-block;
}

.footer a:hover{
  color:#fff;
  transform:translateX(3px);
}

.footer-grid{
  display:grid;
  grid-template-columns:1.2fr .8fr .8fr .8fr;
  gap:22px;
  position:relative;
  z-index:1;
}

.footer h3,.footer h4{
  color:#fff;
  margin:0 0 12px;
  font-size:16px;
  font-weight:700;
}

.footer h3{font-size:19px}

.small{
  font-size:13px;
  color:#94a3b8;
  line-height:1.9;
}

.footer .small a{color:#cbd5e1}

/* ===== Back to top ===== */
.to-top{
  position:fixed;
  right:18px;
  bottom:18px;
  width:46px;
  height:46px;
  border-radius:50%;
  background:var(--grad-brand);
  color:#fff;
  border:0;
  display:none;
  place-items:center;
  cursor:pointer;
  z-index:60;
  font-size:18px;
  font-weight:700;
  box-shadow:var(--shadow-glow);
  transition:transform .3s var(--ease),box-shadow .3s var(--ease);
  animation:fadeUp .4s var(--ease) both;
}

.to-top:hover{
  transform:translateY(-4px) scale(1.06);
  box-shadow:0 16px 36px rgba(31,111,235,.45);
}

.to-top:active{transform:scale(.94)}

/* ===== Animations ===== */
@keyframes fadeUp{
  from{opacity:0;transform:translateY(18px)}
  to{opacity:1;transform:translateY(0)}
}

@keyframes fadeIn{
  from{opacity:0}
  to{opacity:1}
}

.section{
  animation:fadeUp .7s var(--ease) both;
}

.section:nth-of-type(2){animation-delay:.05s}
.section:nth-of-type(3){animation-delay:.1s}
.section:nth-of-type(4){animation-delay:.15s}

.grid > .card,
.article-list > .article-item,
#faqList > .faq-item{
  animation:fadeUp .6s var(--ease) both;
}

.grid > .card:nth-child(1),
.article-list > .article-item:nth-child(1){animation-delay:.04s}
.grid > .card:nth-child(2),
.article-list > .article-item:nth-child(2){animation-delay:.08s}
.grid > .card:nth-child(3),
.article-list > .article-item:nth-child(3){animation-delay:.12s}
.grid > .card:nth-child(4),
.article-list > .article-item:nth-child(4){animation-delay:.16s}
.grid > .card:nth-child(5),
.article-list > .article-item:nth-child(5){animation-delay:.20s}
.grid > .card:nth-child(6),
.article-list > .article-item:nth-child(6){animation-delay:.24s}
.article-list > .article-item:nth-child(7){animation-delay:.28s}
.article-list > .article-item:nth-child(8){animation-delay:.32s}
.article-list > .article-item:nth-child(9){animation-delay:.36s}
.article-list > .article-item:nth-child(10){animation-delay:.40s}

/* ===== Scrollbar ===== */
::-webkit-scrollbar{width:10px;height:10px}
::-webkit-scrollbar-track{background:transparent}
::-webkit-scrollbar-thumb{
  background:linear-gradient(180deg,var(--brand),var(--brand-3));
  border-radius:10px;
  border:2px solid var(--bg);
}
::-webkit-scrollbar-thumb:hover{background:var(--brand-2)}

/* ===== Selection ===== */
::selection{
  background:rgba(31,111,235,.22);
  color:var(--text);
}

/* ===== Focus ===== */
a:focus-visible,
button:focus-visible{
  outline:2px solid var(--brand);
  outline-offset:3px;
  border-radius:6px;
}

/* ===== Responsive ===== */
@media (max-width:1080px){
  .nav-links{gap:2px}
  .nav-links a{padding:7px 9px;font-size:14px}
}

@media (max-width:980px){
  .hero{padding:38px 0 30px}
  .hero-grid{grid-template-columns:1fr;gap:24px}
  .hero p{max-width:100%}
  .hero-card{max-width:640px}
  .grid-3{grid-template-columns:1fr 1fr}
  .footer-grid{grid-template-columns:1fr 1fr;gap:24px}
  .nav-links{display:none}
  .section{padding:36px 0}
}

@media (max-width:680px){
  :root{--header-h:64px}
  body{font-size:15.5px}
  .hero{padding:30px 0 24px}
  .hero h1{font-size:26px}
  .hero p{font-size:15px}
  .badge{font-size:12px;padding:6px 12px}
  .stats{gap:8px}
  .stat{padding:12px 8px}
  .stat strong{font-size:19px}
  .stat span{font-size:11.5px}
  .hero-card{padding:18px}
  .grid-3,.grid-2{grid-template-columns:1fr}
  .grid{gap:14px}
  .card{padding:16px;border-radius:14px}
  .card h3{font-size:16.5px}
  .article-item{grid-template-columns:1fr;gap:10px;padding:12px}
  .article-thumb{width:100%;height:150px}
  .article-item:hover{transform:translateY(-4px)}
  .article-item h3{font-size:16px}
  .section{padding:30px 0}
  .section h2{font-size:21px}
  .section .lead{font-size:14.5px;margin-bottom:18px}
  .faq-q{font-size:15px;padding:14px 44px 14px 14px}
  .faq-q::after{width:24px;height:24px;right:14px;font-size:16px}
  .faq-a{padding:0 14px 14px;font-size:14px}
  #howto ol li{padding:10px 10px 10px 46px;font-size:14px}
  #howto ol li::before{width:24px;height:24px;left:10px;font-size:12px}
  .footer{padding:32px 0 24px;margin-top:30px}
  .footer-grid{grid-template-columns:1fr;gap:20px}
  .to-top{right:12px;bottom:12px;width:42px;height:42px}
  .nav{padding:10px 0;gap:10px}
  .logo{font-size:17px}
  .logo-mark{width:34px;height:34px;border-radius:10px;font-size:14px}
  .nav-actions{gap:8px}
  .btn{padding:8px 12px;font-size:13px}
  .breadcrumb{font-size:12px;padding-bottom:10px}
}

@media (max-width:400px){
  .hero h1{font-size:23px}
  .stat strong{font-size:17px}
  .stat span{font-size:11px}
  .nav-actions .btn:first-child{display:none}
}

/* ===== Reduced motion ===== */
@media (prefers-reduced-motion:reduce){
  *,*::before,*::after{
    animation-duration:.001ms !important;
    animation-iteration-count:1 !important;
    transition-duration:.001ms !important;
    scroll-behavior:auto !important;
  }
}

/* ===== Print ===== */
@media print{
  .header,.to-top,.footer{display:none}
  body{background:#fff;color:#000}
  .card,.hero-card,.article-item,.faq-item{box-shadow:none;border:1px solid #ccc}
}