/* ============================================================
   qq-app.org — Stylesheet (QQ brand palette, no frameworks)
   ============================================================ */
:root{
  --qq:#0099FF;        /* QQ blue */
  --qq-light:#28B7FF;
  --qq-dark:#0C2074;   /* dark navy nav */
  --red:#CF222E;       /* QQ scarf red accent */
  --ink:#1A1A1A;
  --muted:#5b6b7a;
  --line:#e6eaef;
  --bg-soft:#f5f9ff;
}
*{box-sizing:border-box;margin:0;padding:0;}
html{scroll-behavior:smooth;}
body{font-family:'Inter',-apple-system,BlinkMacSystemFont,Arial,sans-serif;color:var(--ink);line-height:1.6;background:#fff;-webkit-font-smoothing:antialiased;}
a{color:var(--qq);text-decoration:none;}
a:hover{text-decoration:underline;}
img{max-width:100%;display:block;}
h1,h2,h3,h4{line-height:1.2;color:var(--ink);}

.wrap{max-width:1180px;margin:0 auto;padding:0 24px;}
@media(max-width:600px){.wrap{padding:0 16px;}}
.sec{padding:72px 0;border-bottom:1px solid var(--line);}
.sec.alt{background:var(--bg-soft);}
.sec.dark{background:var(--qq-dark);}
.lbl{display:block;text-align:center;font-size:12px;font-weight:700;letter-spacing:.14em;text-transform:uppercase;color:var(--qq);margin-bottom:12px;}
.dark .lbl{color:var(--qq-light);}
.h2{font-size:clamp(1.7rem,3.2vw,2.5rem);font-weight:900;letter-spacing:-.03em;text-align:center;margin-bottom:14px;}
.dark .h2{color:#fff;}
.h2-sub{font-size:1.02rem;color:var(--muted);text-align:center;max-width:640px;margin:0 auto 44px;}
.dark .h2-sub{color:rgba(255,255,255,.7);}

/* ── NAV ── */
.site-nav{position:sticky;top:0;z-index:1000;background:var(--qq-dark);box-shadow:0 2px 12px rgba(0,0,0,.12);}
.nav-inner{max-width:1180px;margin:0 auto;padding:0 24px;height:64px;display:flex;align-items:center;gap:20px;}
.nav-logo{display:flex;align-items:center;gap:9px;font-weight:900;font-size:20px;color:#fff;}
.nav-logo:hover{text-decoration:none;}
.nav-logo img{border-radius:7px;background:#fff;padding:2px;}
.nav-links{list-style:none;display:flex;gap:6px;margin-left:18px;}
.nav-links a{color:rgba(255,255,255,.86);font-size:14.5px;font-weight:600;padding:8px 14px;border-radius:8px;transition:.15s;}
.nav-links a:hover,.nav-links a.active{background:rgba(255,255,255,.14);color:#fff;text-decoration:none;}
.nav-ctas{margin-left:auto;display:flex;align-items:center;gap:10px;}
.btn-nav-dl{background:var(--qq);color:#fff;font-size:14px;font-weight:700;padding:9px 18px;border-radius:8px;transition:.15s;white-space:nowrap;}
.btn-nav-dl:hover{background:var(--qq-light);text-decoration:none;}
.nav-hamburger{display:none;flex-direction:column;gap:5px;background:none;border:none;cursor:pointer;padding:6px;margin-left:auto;}
.nav-hamburger span{width:24px;height:2px;background:#fff;border-radius:2px;}
@media(max-width:780px){
  .nav-links{display:none;position:absolute;top:64px;left:0;right:0;background:var(--qq-dark);flex-direction:column;padding:10px 24px 16px;gap:2px;}
  .nav-links.open{display:flex;}
  .nav-ctas{margin-left:0;}
  .nav-hamburger{display:flex;}
}

/* ── TL;DR ── */
.tldr{background:linear-gradient(90deg,var(--qq),var(--qq-light));color:#fff;font-size:14.5px;text-align:center;padding:11px 24px;font-weight:500;}
.tldr strong{font-weight:800;}
.tldr a{color:#fff;text-decoration:underline;font-weight:700;}

/* ── BREADCRUMB ── */
.breadcrumb{background:var(--bg-soft);border-bottom:1px solid var(--line);}
.bc-wrap{max-width:1180px;margin:0 auto;padding:11px 24px;font-size:13px;color:var(--muted);}
.bc-wrap a{color:var(--qq);}
.bc-sep{margin:0 8px;color:#aab;}

/* ── HERO ── */
.hero{background:linear-gradient(135deg,#eaf4ff 0%,#f5f9ff 100%);padding:64px 0;}
.hero-in{max-width:1180px;margin:0 auto;padding:0 24px;display:grid;grid-template-columns:1.15fr .85fr;gap:48px;align-items:center;}
.hero h1{font-size:clamp(2rem,4.4vw,3.2rem);font-weight:900;letter-spacing:-.04em;margin-bottom:18px;}
.hero h1 .hl{color:var(--qq);}
.hero-sub{font-size:1.12rem;color:var(--muted);margin-bottom:28px;max-width:540px;}
.hero-btns{display:flex;gap:14px;flex-wrap:wrap;}
.btn-primary{background:var(--qq);color:#fff;font-size:15px;font-weight:700;padding:14px 28px;border-radius:10px;transition:.15s;box-shadow:0 6px 18px rgba(0,153,255,.32);}
.btn-primary:hover{background:var(--qq-light);text-decoration:none;transform:translateY(-1px);}
.btn-outline{background:transparent;color:var(--qq);font-size:15px;font-weight:700;padding:14px 28px;border-radius:10px;border:2px solid var(--qq);transition:.15s;}
.btn-outline:hover{background:var(--qq);color:#fff;text-decoration:none;}
.hero-visual{display:flex;justify-content:center;}
@media(max-width:820px){.hero-in{grid-template-columns:1fr;text-align:center;}.hero-btns{justify-content:center;}.hero-sub{margin-left:auto;margin-right:auto;}.hero-visual{display:none;}}

/* ── STATS ── */
.stats-grid{display:grid;grid-template-columns:repeat(4,1fr);gap:1px;background:var(--line);border:1px solid var(--line);border-radius:14px;overflow:hidden;}
.stats-grid>div{background:#fff;padding:28px 18px;text-align:center;}
.stat-n{font-size:2rem;font-weight:900;color:var(--qq);letter-spacing:-.03em;}
.stat-l{font-size:13px;color:var(--muted);margin-top:4px;}
@media(max-width:640px){.stats-grid{grid-template-columns:repeat(2,1fr);}}

/* ── PLATFORM TABLE ── */
.tbl-wrap{overflow-x:auto;border-radius:14px;box-shadow:0 4px 20px rgba(0,0,0,.06);border:1px solid var(--line);}
.dl-table{width:100%;border-collapse:collapse;font-size:14.5px;min-width:560px;}
.dl-table th{background:var(--qq-dark);color:#fff;text-align:left;padding:14px 18px;font-size:13px;font-weight:700;}
.dl-table td{padding:14px 18px;border-bottom:1px solid var(--line);color:#444;vertical-align:middle;}
.dl-table tr:last-child td{border-bottom:none;}
.dl-table tr:nth-child(even) td{background:var(--bg-soft);}
.dl-table .btn-sm{display:inline-block;background:var(--qq);color:#fff;font-size:13px;font-weight:700;padding:7px 16px;border-radius:7px;}
.dl-table .btn-sm:hover{background:var(--qq-light);text-decoration:none;}

/* ── DOWNLOAD CARDS ── */
.dl-cards{display:grid;grid-template-columns:repeat(4,1fr);gap:18px;}
.dl-card{background:#fff;border:1px solid var(--line);border-radius:14px;padding:28px 22px;text-align:center;box-shadow:0 4px 18px rgba(0,0,0,.05);transition:.18s;}
.dl-card:hover{box-shadow:0 10px 30px rgba(0,153,255,.14);transform:translateY(-3px);}
.dl-card .ico{font-size:2.4rem;margin-bottom:12px;}
.dl-card h3{font-size:1.05rem;font-weight:800;margin-bottom:6px;}
.dl-card p{font-size:13px;color:var(--muted);margin-bottom:18px;}
.dl-card .btn-dl{display:block;background:var(--qq);color:#fff;font-weight:700;font-size:14px;padding:11px;border-radius:8px;}
.dl-card .btn-dl:hover{background:var(--qq-light);text-decoration:none;}
@media(max-width:860px){.dl-cards{grid-template-columns:repeat(2,1fr);}}
@media(max-width:460px){.dl-cards{grid-template-columns:1fr;}}

/* ── FEATURE CARDS ── */
.feat-grid{display:grid;grid-template-columns:repeat(3,1fr);gap:22px;}
.feat-card{background:#fff;border:1px solid var(--line);border-radius:14px;padding:28px 24px;transition:.18s;}
.feat-card:hover{box-shadow:0 8px 26px rgba(0,0,0,.08);border-color:#cfe4ff;}
.feat-ico{width:52px;height:52px;border-radius:12px;background:linear-gradient(135deg,var(--qq),var(--qq-light));display:flex;align-items:center;justify-content:center;margin-bottom:16px;}
.feat-ico svg{width:26px;height:26px;fill:#fff;}
.feat-card h3{font-size:1.12rem;font-weight:800;margin-bottom:8px;}
.feat-card p{font-size:14px;color:var(--muted);}
@media(max-width:820px){.feat-grid{grid-template-columns:1fr 1fr;}}
@media(max-width:520px){.feat-grid{grid-template-columns:1fr;}}

/* ── SCREENSHOTS GRID ── */
.shots-3{display:grid;grid-template-columns:repeat(3,1fr);gap:16px;}
.shots-2{display:grid;grid-template-columns:repeat(2,1fr);gap:20px;margin-top:20px;}
.shot{border:1px solid var(--line);border-radius:12px;overflow:hidden;background:#fff;box-shadow:0 4px 16px rgba(0,0,0,.05);}
.shot img{width:100%;height:200px;object-fit:cover;display:block;}
.shot .cap{font-size:12.5px;color:var(--muted);padding:9px 14px;border-top:1px solid var(--line);}
@media(max-width:780px){.shots-3{grid-template-columns:1fr 1fr;}}
@media(max-width:520px){.shots-3,.shots-2{grid-template-columns:1fr;}}

/* ── HOW IT WORKS ── */
.steps{display:grid;grid-template-columns:repeat(4,1fr);gap:20px;}
.step{text-align:center;padding:10px;}
.step-n{width:46px;height:46px;border-radius:50%;background:var(--qq);color:#fff;font-weight:900;display:flex;align-items:center;justify-content:center;margin:0 auto 14px;font-size:18px;}
.step h3{font-size:1.02rem;font-weight:700;margin-bottom:7px;}
.step p{font-size:13.5px;color:var(--muted);}
@media(max-width:780px){.steps{grid-template-columns:1fr 1fr;}}
@media(max-width:420px){.steps{grid-template-columns:1fr;}}

/* ── COMPARISON ── */
.cmp-wrap{overflow-x:auto;border-radius:14px;box-shadow:0 4px 20px rgba(0,0,0,.06);border:1px solid var(--line);}
.cmp-table{width:100%;border-collapse:collapse;font-size:14px;min-width:560px;}
.cmp-table th{background:var(--qq-dark);color:#fff;text-align:left;padding:13px 16px;font-size:12.5px;font-weight:700;}
.cmp-table th.hl{background:var(--qq);}
.cmp-table td{padding:11px 16px;border-bottom:1px solid var(--line);color:#444;}
.cmp-table tr:nth-child(even) td{background:var(--bg-soft);}
.cmp-table tr:last-child td{border-bottom:none;}
.yes{color:#1a7f37;font-weight:700;}
.no{color:#cf222e;}

/* ── USE CASES ── */
.uc-grid{display:grid;grid-template-columns:repeat(3,1fr);gap:20px;}
.uc{background:#fff;border:1px solid var(--line);border-radius:14px;overflow:hidden;}
.uc img{width:100%;height:160px;object-fit:cover;}
.uc-b{padding:18px 20px;}
.uc-b h3{font-size:1.05rem;font-weight:800;margin-bottom:7px;}
.uc-b p{font-size:13.5px;color:var(--muted);}
@media(max-width:820px){.uc-grid{grid-template-columns:1fr;}}

/* ── FAQ ── */
.faq-list{display:flex;flex-direction:column;gap:10px;max-width:840px;margin:0 auto;}
.faq-item{background:#fff;border:1.5px solid var(--line);border-radius:12px;overflow:hidden;transition:.15s;}
.faq-item[open]{border-color:var(--qq);box-shadow:0 4px 18px rgba(0,153,255,.08);}
.faq-q{list-style:none;display:flex;justify-content:space-between;align-items:center;gap:10px;padding:16px 20px;cursor:pointer;font-size:15px;font-weight:700;color:var(--qq-dark);}
.faq-q::-webkit-details-marker{display:none;}
.faq-item[open] .faq-q{color:var(--qq);}
.faq-ico{width:24px;height:24px;border-radius:50%;background:var(--bg-soft);flex-shrink:0;position:relative;}
.faq-item[open] .faq-ico{background:var(--qq);}
.faq-ico::before,.faq-ico::after{content:'';position:absolute;top:50%;left:50%;transform:translate(-50%,-50%);background:#888;border-radius:2px;}
.faq-item[open] .faq-ico::before,.faq-item[open] .faq-ico::after{background:#fff;}
.faq-ico::before{width:11px;height:2px;}
.faq-ico::after{width:2px;height:11px;transition:opacity .2s;}
.faq-item[open] .faq-ico::after{opacity:0;}
.faq-a{padding:0 20px 18px;border-top:1px solid var(--line);}
.faq-a p{font-size:14px;color:var(--muted);margin-top:14px;}

/* ── 2-COL TEXT+IMAGE ── */
.split{display:grid;grid-template-columns:1fr 1fr;gap:40px;align-items:center;}
.split img{border-radius:14px;border:1px solid var(--line);box-shadow:0 6px 24px rgba(0,0,0,.07);}
.split h3{font-size:1.4rem;font-weight:800;margin-bottom:14px;}
.split p{font-size:15px;color:var(--muted);margin-bottom:12px;}
@media(max-width:780px){.split{grid-template-columns:1fr;}}

/* ── CTA ── */
.cta-final{background:linear-gradient(135deg,var(--qq),var(--qq-light));text-align:center;padding:64px 24px;color:#fff;}
.cta-final h2{font-size:clamp(1.7rem,3.2vw,2.4rem);font-weight:900;margin-bottom:12px;color:#fff;}
.cta-final p{font-size:1.05rem;opacity:.92;max-width:560px;margin:0 auto 28px;}
.cta-btns{display:flex;gap:14px;justify-content:center;flex-wrap:wrap;}
.btn-cta-w{background:#fff;color:var(--qq);font-weight:800;font-size:15px;padding:14px 30px;border-radius:10px;}
.btn-cta-w:hover{text-decoration:none;transform:translateY(-1px);}
.btn-cta-o{background:rgba(255,255,255,.16);color:#fff;font-weight:700;font-size:15px;padding:14px 26px;border-radius:10px;border:1.5px solid rgba(255,255,255,.5);}
.btn-cta-o:hover{background:rgba(255,255,255,.26);text-decoration:none;}

/* ── prose (privacy/legal) ── */
.prose{max-width:820px;margin:0 auto;}
.prose h1{font-size:2rem;font-weight:900;margin-bottom:10px;}
.prose .upd{font-size:13px;color:var(--muted);margin-bottom:26px;}
.prose h2{font-size:1.2rem;font-weight:800;margin:26px 0 10px;color:var(--qq-dark);}
.prose p{font-size:15px;color:#444;line-height:1.8;margin-bottom:12px;}

/* ── FOOTER ── */
.site-footer{background:var(--qq-dark);color:rgba(255,255,255,.78);}
.footer-top{max-width:1180px;margin:0 auto;padding:48px 24px 32px;}
.footer-grid{display:grid;grid-template-columns:1.6fr 1fr 1fr 1fr;gap:32px;}
.footer-brand-link{display:flex;align-items:center;gap:9px;font-size:20px;font-weight:900;color:#fff;margin-bottom:12px;}
.footer-brand-link img{border-radius:7px;background:#fff;padding:2px;}
.footer-brand-link:hover{text-decoration:none;}
.footer-tagline{font-size:13.5px;color:rgba(255,255,255,.6);max-width:300px;}
.footer-col h4{font-size:13px;text-transform:uppercase;letter-spacing:.08em;color:#fff;margin-bottom:14px;}
.footer-col ul{list-style:none;}
.footer-col li{margin-bottom:9px;}
.footer-col a{color:rgba(255,255,255,.72);font-size:14px;}
.footer-col a:hover{color:#fff;}
.footer-disc{border-top:1px solid rgba(255,255,255,.12);padding:20px 24px;max-width:1180px;margin:0 auto;}
.footer-disc p{font-size:12px;color:rgba(255,255,255,.55);line-height:1.7;}
.footer-disc a{color:rgba(255,255,255,.75);}
@media(max-width:780px){.footer-grid{grid-template-columns:1fr 1fr;}}
@media(max-width:460px){.footer-grid{grid-template-columns:1fr;}}

/* ============================================================
   QQ-STYLE IMMERSIVE HERO (matches official im.qq.com)
   ============================================================ */
.qq-hero{
  position:relative;
  min-height:calc(100vh - 64px);
  display:flex;
  flex-direction:column;
  align-items:center;
  justify-content:center;
  text-align:center;
  padding:60px 24px 40px;
  overflow:hidden;
  background:
    linear-gradient(110deg,
      #1a7fb8 0%, #169fbe 12%, #14b3ad 22%,
      #2f7fd0 34%, #5a66d4 46%, #8a63d8 56%,
      #b06fd0 66%, #cf86c4 76%,
      #e6a6b0 88%, #f3c8a4 100%);
}
/* dense vertical "curtain" of light beams — matches official QQ hero */
.qq-hero::before{
  content:"";position:absolute;inset:0;
  background:repeating-linear-gradient(90deg,
    rgba(255,255,255,.22) 0 1px,
    rgba(255,255,255,.07) 1px 7px,
    rgba(0,0,0,.10) 7px 8px,
    rgba(255,255,255,.07) 8px 14px);
  mix-blend-mode:soft-light;pointer-events:none;
}
/* soft glowing smiley accent on the right, like the original */
.qq-hero::after{
  content:"";position:absolute;
  right:9%;top:46%;width:88px;height:88px;
  border-radius:50%;
  border:2px solid rgba(255,255,255,.55);
  box-shadow:0 0 24px rgba(255,255,255,.5), inset 0 0 18px rgba(255,255,255,.35);
  background:
    radial-gradient(circle at 35% 42%, rgba(255,255,255,.9) 0 3px, transparent 4px),
    radial-gradient(circle at 65% 42%, rgba(255,255,255,.9) 0 3px, transparent 4px);
  pointer-events:none;z-index:1;
}
@media(max-width:780px){.qq-hero::after{display:none;}}
.qq-hero>*{position:relative;z-index:2;}
.qq-hero h1{
  font-size:clamp(2rem,5vw,3.6rem);
  font-weight:900;letter-spacing:-.02em;
  color:#fff;line-height:1.08;
  text-shadow:0 0 28px rgba(255,255,255,.45), 0 2px 24px rgba(0,0,0,.18);
  margin-bottom:14px;
}
.qq-hero .hero-tag{
  font-size:clamp(1rem,2vw,1.25rem);
  color:rgba(255,255,255,.92);
  margin-bottom:40px;font-weight:500;
  text-shadow:0 1px 12px rgba(0,0,0,.15);
}
.qq-dl-btn{
  display:inline-flex;align-items:center;gap:14px;
  background:rgba(255,255,255,.92);color:#1a1a1a;
  font-size:clamp(1.2rem,2.6vw,1.7rem);font-weight:800;
  padding:18px 48px;border-radius:60px;
  backdrop-filter:blur(8px);-webkit-backdrop-filter:blur(8px);
  border:1px solid rgba(255,255,255,.6);
  box-shadow:0 0 44px rgba(255,255,255,.55), 0 12px 40px rgba(0,0,0,.18);
  transition:.18s;
}
.qq-dl-btn:hover{transform:translateY(-2px);box-shadow:0 16px 48px rgba(0,0,0,.28);text-decoration:none;color:#1a1a1a;}
.qq-dl-btn .dl-ico{
  width:34px;height:34px;border-radius:50%;
  border:2.5px solid #1a1a1a;display:flex;align-items:center;justify-content:center;
  font-size:18px;flex-shrink:0;
}
.qq-ver{margin-top:22px;font-size:14px;font-weight:700;color:rgba(255,255,255,.95);letter-spacing:.02em;text-shadow:0 1px 8px rgba(0,0,0,.2);}
.qq-more{margin-top:10px;font-size:14px;}
.qq-more a{color:rgba(255,255,255,.92);font-weight:500;}
.qq-more a:hover{color:#fff;}
/* platform icon row */
.qq-platforms{
  display:flex;gap:clamp(20px,4vw,52px);flex-wrap:wrap;justify-content:center;
  margin-top:56px;
}
.qq-plat{display:flex;flex-direction:column;align-items:center;gap:8px;color:rgba(255,255,255,.88);font-size:13px;font-weight:500;transition:.15s;}
.qq-plat:hover{color:#fff;text-decoration:none;transform:translateY(-2px);}
.qq-plat svg{width:30px;height:30px;fill:rgba(255,255,255,.9);}
.qq-plat:hover svg{fill:#fff;}
/* hero bottom links */
.qq-hero-foot{margin-top:auto;padding-top:48px;font-size:13px;color:rgba(255,255,255,.8);}
.qq-hero-foot a{color:rgba(255,255,255,.92);}
.qq-hero-foot .cw{display:block;margin-top:6px;color:rgba(255,255,255,.65);font-size:12px;}

/* transparent nav variant for hero pages */
.site-nav.nav-on-hero{background:transparent;box-shadow:none;position:absolute;top:0;left:0;right:0;}
.site-nav.nav-on-hero .nav-links a{color:#fff;text-shadow:0 1px 8px rgba(0,0,0,.25);}
.site-nav.nav-on-hero .nav-links a:hover,.site-nav.nav-on-hero .nav-links a.active{background:rgba(255,255,255,.22);}
.site-nav.nav-on-hero .nav-logo{text-shadow:0 1px 8px rgba(0,0,0,.25);}
.site-nav.nav-on-hero .btn-nav-dl{display:none;}
@media(max-width:780px){.site-nav.nav-on-hero{background:var(--qq-dark);position:sticky;}.site-nav.nav-on-hero .btn-nav-dl{display:inline-block;background:var(--qq);border:none;}}

/* ── deep article content sections ── */
.article{max-width:880px;margin:0 auto;}
.article h2{text-align:left;font-size:clamp(1.4rem,2.6vw,1.9rem);margin-bottom:14px;}
.article h3{font-size:1.15rem;font-weight:800;color:var(--qq-dark);margin:24px 0 10px;}
.article p{font-size:15.5px;color:#415061;line-height:1.85;margin-bottom:14px;}
.article ul{margin:0 0 16px 22px;}
.article li{font-size:15px;color:#415061;line-height:1.8;margin-bottom:8px;}
.article .lead{font-size:17px;color:#2a3744;line-height:1.8;margin-bottom:18px;}
.callout{background:#fff;border:1px solid var(--line);border-left:4px solid var(--qq);border-radius:0 12px 12px 0;padding:18px 22px;margin:20px 0;}
.callout strong{color:var(--qq-dark);}
.two-col{display:grid;grid-template-columns:1fr 1fr;gap:32px;margin-top:8px;}
@media(max-width:780px){.two-col{grid-template-columns:1fr;}}

/* ── SEO text block ── */
.seo-block{background:var(--bg-soft);border-top:1px solid var(--line);border-bottom:1px solid var(--line);}
.seo-block .wrap{max-width:900px;padding-top:40px;padding-bottom:40px;}
.seo-block h2{font-size:1.2rem;font-weight:800;color:var(--qq-dark);text-align:left;margin-bottom:12px;}
.seo-block p{font-size:14px;color:#5b6b7a;line-height:1.8;margin:0;}

/* ── install guide page ── */
.guide-step{display:grid;grid-template-columns:54px 1fr;gap:18px;align-items:start;margin-bottom:28px;}
.guide-step .gs-n{width:46px;height:46px;border-radius:50%;background:var(--qq);color:#fff;font-weight:900;font-size:20px;display:flex;align-items:center;justify-content:center;}
.guide-step h3{font-size:1.15rem;font-weight:800;color:var(--qq-dark);margin-bottom:8px;}
.guide-step p{font-size:15px;color:#415061;line-height:1.8;margin-bottom:12px;}
.guide-step img{border:1px solid var(--line);border-radius:10px;box-shadow:0 4px 16px rgba(0,0,0,.06);width:100%;max-width:520px;}
.guide-toc{background:#fff;border:1px solid var(--line);border-radius:12px;padding:20px 24px;margin-bottom:32px;}
.guide-toc h2{text-align:left;font-size:1.05rem;margin-bottom:10px;color:var(--qq-dark);}
.guide-toc ul{margin:0 0 0 18px;}
.guide-toc li{font-size:14.5px;margin-bottom:6px;}
.video-wrap{position:relative;padding-bottom:56.25%;height:0;border-radius:12px;overflow:hidden;box-shadow:0 6px 24px rgba(0,0,0,.12);margin:8px 0 4px;}
.video-wrap iframe{position:absolute;top:0;left:0;width:100%;height:100%;border:0;}
.err-item{background:#fff;border:1px solid var(--line);border-left:4px solid var(--red);border-radius:0 10px 10px 0;padding:16px 20px;margin-bottom:14px;}
.err-item h3{font-size:1rem;font-weight:800;color:var(--qq-dark);margin-bottom:6px;}
.err-item p{font-size:14px;color:#415061;line-height:1.75;margin:0;}

/* ── errors hub ── */
.err-grid{display:grid;grid-template-columns:repeat(2,1fr);gap:18px;}
.err-card{display:block;background:#fff;border:1px solid var(--line);border-left:4px solid var(--red);border-radius:0 12px 12px 0;padding:22px 24px;transition:.16s;}
.err-card:hover{box-shadow:0 8px 26px rgba(0,0,0,.08);text-decoration:none;transform:translateY(-2px);}
.err-card h3{font-size:1.08rem;font-weight:800;color:var(--qq-dark);margin-bottom:7px;}
.err-card p{font-size:13.5px;color:#5b6b7a;line-height:1.65;margin:0;}
.err-card .err-tag{display:inline-block;font-size:11px;font-weight:700;color:var(--red);background:#fdeaea;padding:3px 10px;border-radius:6px;margin-bottom:10px;}
@media(max-width:680px){.err-grid{grid-template-columns:1fr;}}
/* fix-page step boxes */
.fix-step{background:#fff;border:1px solid var(--line);border-radius:12px;padding:18px 22px;margin-bottom:14px;display:grid;grid-template-columns:38px 1fr;gap:16px;align-items:start;}
.fix-step .fn{width:30px;height:30px;border-radius:50%;background:var(--qq);color:#fff;font-weight:800;font-size:15px;display:flex;align-items:center;justify-content:center;}
.fix-step h3{font-size:1.02rem;font-weight:800;color:var(--qq-dark);margin-bottom:5px;}
.fix-step p{font-size:14px;color:#415061;line-height:1.7;margin:0;}

/* ── utility classes (replacing inline styles for cleaner HTML) ── */
.lbl-left{text-align:left;}
.article h1.fix-h1{font-size:clamp(1.7rem,3.4vw,2.4rem);font-weight:900;margin-bottom:14px;}
.seo-block h2.seo-h2-mt{margin-top:24px;}
.err-card.ec-blue{border-left-color:var(--qq);}
.err-card .err-tag.tag-blue{color:var(--qq);background:#e6f4ff;}
.footer-region{margin-bottom:8px;}
.note-hint{font-size:13px;color:#9aa7b8;}