/* ===========================================================
   Aizhi — AI Tools & Guides   (theme: news/ai_hub)
   Lightweight, single-file, system-font, zero-JS.
   =========================================================== */
:root{
  --bg:#0b0f1a; --surface:#11162a; --surface-2:#161d36;
  --text:#e8ebf5; --muted:#9aa3c0; --line:#222a47;
  --brand:#7c8bff; --brand-2:#a855f7; --accent:#22d3ee;
  --radius:14px; --maxw:1140px;
  --grad:linear-gradient(135deg,#7c8bff 0%,#a855f7 55%,#22d3ee 120%);
  --shadow:0 8px 30px rgba(2,6,23,.45);
  --font:-apple-system,BlinkMacSystemFont,"Segoe UI",Roboto,Inter,"Helvetica Neue",Arial,"PingFang SC","Microsoft Yahei",sans-serif;
}
*{box-sizing:border-box}
html{-webkit-text-size-adjust:100%}
body{
  margin:0;font-family:var(--font);background:var(--bg);color:var(--text);
  line-height:1.65;font-size:16px;-webkit-font-smoothing:antialiased;
}
a{color:var(--brand);text-decoration:none}
a:hover{color:var(--accent)}
img{max-width:100%;height:auto;display:block}
h1,h2,h3{line-height:1.25;margin:0 0 .5em;font-weight:700;letter-spacing:-.01em}
p{margin:0 0 1em}
.container{max-width:var(--maxw);margin:0 auto;padding:0 20px}

/* ---------- Header ---------- */
.site-header{position:sticky;top:0;z-index:50;background:rgba(11,15,26,.82);
  backdrop-filter:saturate(140%) blur(10px);border-bottom:1px solid var(--line)}
.header-inner{display:flex;align-items:center;gap:18px;min-height:64px}
.brand{display:inline-flex;align-items:center;gap:9px;font-weight:800;font-size:20px;color:var(--text);letter-spacing:-.02em}
.brand:hover{color:var(--text)}
.brand-mark{display:inline-grid;place-items:center;width:30px;height:30px;border-radius:9px;
  background:var(--grad);color:#0b0f1a;font-size:16px;box-shadow:var(--shadow)}
.brand-text{background:var(--grad);-webkit-background-clip:text;background-clip:text;-webkit-text-fill-color:transparent}
.site-nav{margin-left:auto}
.site-nav ul{display:flex;flex-wrap:wrap;gap:4px;list-style:none;margin:0;padding:0}
.site-nav a{display:inline-block;padding:8px 13px;border-radius:9px;color:var(--muted);font-size:14.5px;font-weight:600}
.site-nav a:hover{color:var(--text);background:var(--surface-2)}

/* ---------- Hero ---------- */
.hero{position:relative;overflow:hidden;border-bottom:1px solid var(--line);
  background:radial-gradient(1100px 380px at 18% -10%,rgba(124,139,255,.20),transparent 60%),
             radial-gradient(900px 360px at 92% 0,rgba(168,85,247,.16),transparent 60%)}
.hero .container{padding-top:60px;padding-bottom:54px}
.hero-title{font-size:clamp(30px,5vw,50px);margin:0 0 14px;max-width:18ch}
.hero-title .grad{background:var(--grad);-webkit-background-clip:text;background-clip:text;-webkit-text-fill-color:transparent}
.hero-sub{font-size:clamp(16px,2.2vw,19px);color:var(--muted);max-width:62ch;margin:0 0 22px}
.hero-cats{display:flex;flex-wrap:wrap;gap:10px}
.chip{display:inline-block;padding:8px 15px;border:1px solid var(--line);border-radius:999px;
  background:var(--surface);color:var(--text);font-size:14px;font-weight:600}
.chip:hover{border-color:var(--brand);color:var(--text);background:var(--surface-2)}

/* ---------- Sections ---------- */
.section{padding:46px 0 8px}
.section-head{display:flex;align-items:baseline;justify-content:space-between;gap:16px;margin-bottom:22px}
.section-head h2{font-size:clamp(20px,3vw,28px);margin:0}
.see-all{color:var(--muted);font-size:14px;font-weight:600;white-space:nowrap}

/* ---------- Cards ---------- */
.card-grid{display:grid;grid-template-columns:repeat(auto-fill,minmax(250px,1fr));gap:18px}
.card{display:block;background:var(--surface);border:1px solid var(--line);border-radius:var(--radius);
  padding:20px;box-shadow:var(--shadow);transition:transform .15s ease,border-color .15s ease}
.card:hover{transform:translateY(-3px);border-color:var(--brand)}
.cat-card{display:flex;align-items:center;gap:13px;font-weight:700;color:var(--text);font-size:17px}
.card-icon{display:inline-grid;place-items:center;min-width:40px;height:40px;border-radius:11px;
  background:var(--surface-2);color:var(--brand);font-size:18px}
.post-card .card-title{font-size:18px;margin:0 0 8px}
.post-card .card-title a{color:var(--text)}
.post-card .card-title a:hover{color:var(--brand)}
.card-meta{color:var(--muted);font-size:13px;margin:0 0 10px}
.card-excerpt{color:var(--muted);font-size:14.5px;margin:0 0 14px;
  display:-webkit-box;-webkit-line-clamp:3;-webkit-box-orient:vertical;overflow:hidden}
.card-readmore{color:var(--brand);font-weight:600;font-size:14px}

/* ---------- Content layout (list/show) ---------- */
.page-wrap{padding:28px 0 10px}
.breadcrumb{font-size:13.5px;color:var(--muted);margin-bottom:18px}
.breadcrumb ol{list-style:none;display:flex;flex-wrap:wrap;gap:8px;margin:0;padding:0}
.breadcrumb li::after{content:"›";margin-left:8px;color:var(--line)}
.breadcrumb li:last-child::after{content:""}
.breadcrumb a{color:var(--muted)}.breadcrumb a:hover{color:var(--brand)}
.content-layout{display:grid;grid-template-columns:minmax(0,1fr) 312px;gap:34px;align-items:start}
.main-content{min-width:0}
.page-h1{font-size:clamp(26px,4vw,38px);margin:0 0 10px}
.category-desc,.article-meta{color:var(--muted)}
.article-meta{font-size:14px;margin:0 0 24px;display:flex;flex-wrap:wrap;gap:10px;align-items:center}
.article-body{font-size:17px;line-height:1.8}
.article-body p{margin:0 0 1.15em}
.article-body h2{font-size:24px;margin:1.6em 0 .5em}
.article-body h3{font-size:20px;margin:1.4em 0 .5em}
.article-body img{border-radius:10px;margin:1.2em 0;border:1px solid var(--line)}
.article-body a{text-decoration:underline;text-underline-offset:2px}

/* Article list (list page) */
.article-list{list-style:none;margin:0;padding:0;display:grid;gap:16px}
.article-item{background:var(--surface);border:1px solid var(--line);border-radius:var(--radius);padding:20px 22px;box-shadow:var(--shadow)}
.article-item h2{font-size:19px;margin:0 0 8px}
.article-item h2 a{color:var(--text)}.article-item h2 a:hover{color:var(--brand)}
.article-item .article-excerpt{color:var(--muted);font-size:14.5px;margin:0 0 10px}
.read-more{font-weight:600;font-size:14px}

/* Prev/Next + related */
.article-pagination{display:flex;flex-wrap:wrap;gap:14px;margin:30px 0;padding-top:20px;border-top:1px solid var(--line)}
.article-pagination>div{flex:1 1 220px;background:var(--surface);border:1px solid var(--line);border-radius:12px;padding:12px 16px}
.article-pagination span{display:block;color:var(--muted);font-size:12px;margin-bottom:3px}
.related-articles{margin-top:36px}
.related-articles h2{font-size:22px;margin-bottom:16px}
.related-articles ul{list-style:none;margin:0;padding:0;display:grid;gap:10px}
.related-articles li{display:flex;justify-content:space-between;gap:14px;padding:11px 14px;background:var(--surface);border:1px solid var(--line);border-radius:10px}
.related-articles time{color:var(--muted);font-size:13px;white-space:nowrap}

/* Pagination */
.pagination{display:flex;flex-wrap:wrap;gap:7px;margin:26px 0 6px}
.page-num{display:inline-block;min-width:38px;text-align:center;padding:8px 12px;border:1px solid var(--line);
  border-radius:9px;background:var(--surface);color:var(--text);font-weight:600;font-size:14px}
.page-num:hover{border-color:var(--brand)}

/* Sidebar */
.sidebar{display:grid;gap:22px;position:sticky;top:84px}
.sidebar-section{background:var(--surface);border:1px solid var(--line);border-radius:var(--radius);padding:18px 20px;box-shadow:var(--shadow)}
.sidebar-section h2{font-size:16px;margin:0 0 12px;padding-bottom:10px;border-bottom:1px solid var(--line)}
.sidebar-section ul{list-style:none;margin:0;padding:0;display:grid;gap:9px}
.sidebar-section a{color:var(--muted);font-size:14.5px}
.sidebar-section a:hover{color:var(--brand)}

/* ---------- Footer ---------- */
.site-footer{margin-top:56px;border-top:1px solid var(--line);background:var(--surface);padding:42px 0 28px}
.footer-cols{display:grid;grid-template-columns:1.6fr 1fr 1fr;gap:28px;margin-bottom:26px}
.footer-tagline{color:var(--muted);font-size:14px;margin-top:12px;max-width:42ch}
.footer-h{font-size:14px;text-transform:uppercase;letter-spacing:.08em;color:var(--text);margin:0 0 12px}
.footer-col ul{list-style:none;margin:0;padding:0;display:grid;gap:8px}
.footer-col a{color:var(--muted);font-size:14px}
.footer-col a:hover{color:var(--brand)}
.partner-links{border-top:1px solid var(--line);padding-top:16px;margin-top:6px;
  display:flex;flex-wrap:wrap;gap:6px 14px;font-size:12.5px}
.partner-links a{color:#56608a}
.partner-links a:hover{color:var(--muted)}
.footer-copy{color:var(--muted);font-size:13px;margin:18px 0 0}

/* ---------- Responsive ---------- */
@media (max-width:880px){
  .content-layout{grid-template-columns:1fr}
  .sidebar{position:static}
  .footer-cols{grid-template-columns:1fr 1fr}
}
@media (max-width:560px){
  .header-inner{flex-wrap:wrap;min-height:0;padding:10px 0;gap:8px 18px}
  .site-nav{margin-left:0;width:100%}
  .site-nav ul{gap:2px}.site-nav a{padding:7px 10px}
  .footer-cols{grid-template-columns:1fr}
}

/* ---------- Article thumbnails (list cards) ---------- */
.article-item{padding:0;overflow:hidden}
.article-card{display:flex;gap:0;align-items:stretch}
.card-thumb-link{flex:0 0 224px;display:block;overflow:hidden;background:var(--surface-2)}
.card-thumb{width:224px;height:100%;min-height:152px;object-fit:cover;border:0;border-radius:0;margin:0;transition:transform .35s ease}
.card-thumb-link:hover .card-thumb{transform:scale(1.06)}
.card-body{flex:1;min-width:0;padding:18px 22px}
.card-body .read-more{display:inline-block;margin-top:2px}
/* ---------- Article hero image (show page) ---------- */
.article-hero{display:block;width:100%;height:clamp(180px,26vw,320px);object-fit:cover;border-radius:12px;margin:.4em 0 1.6em;border:1px solid var(--line);background:var(--surface-2)}
@media (max-width:600px){
  .article-card{flex-direction:column}
  .card-thumb-link{flex:none;width:100%}
  .card-thumb{width:100%;height:188px;min-height:0}
  .card-body{padding:16px 18px}
}