/* ===== fusi.si — AI · Tech · Tools 内容站 · 浅色现代设计系统 ===== */
:root{
  --bg:#f5f7fb;
  --surface:#ffffff;
  --surface-2:#f1f4fa;
  --text:#0f172a;
  --muted:#5b6b7e;
  --line:#e6eaf2;
  --accent:#4f46e5;
  --accent-2:#7c3aed;
  --accent-3:#0ea5e9;
  --good:#10b981;
  --warn:#f59e0b;
  --star:#f59e0b;
  --shadow-sm:0 1px 2px rgba(15,23,42,.05), 0 1px 3px rgba(15,23,42,.06);
  --shadow:0 18px 40px -20px rgba(15,23,42,.25);
  --shadow-lg:0 30px 60px -25px rgba(79,70,229,.35);
  --radius:18px;
  --radius-sm:12px;
  --maxw:1160px;
  --font:"Inter",-apple-system,BlinkMacSystemFont,"Segoe UI",Roboto,"PingFang SC","Microsoft YaHei",Helvetica,Arial,sans-serif;
}
*{box-sizing:border-box}
html{scroll-behavior:smooth}
html,body{margin:0;padding:0}
body{
  font-family:var(--font);
  background:var(--bg);
  color:var(--text);
  line-height:1.7;
  font-size:16px;
  -webkit-font-smoothing:antialiased;
  text-rendering:optimizeLegibility;
}
a{color:var(--accent);text-decoration:none;transition:color .15s}
a:hover{color:var(--accent-2);text-decoration:none}
img{max-width:100%;display:block}
h1,h2,h3,h4{line-height:1.25;color:var(--text);font-weight:800;letter-spacing:-.01em}
.wrap{max-width:var(--maxw);margin:0 auto;padding:0 22px}

/* 双语切换 */
.zh,.en{display:inline}
html[lang="en"] .zh{display:none!important}
html[lang="zh"] .en{display:none!important}
.block-zh,.block-en{display:block}
html[lang="en"] .block-zh{display:none!important}
html[lang="zh"] .block-en{display:none!important}

/* ===== Header ===== */
.site-header{position:sticky;top:0;z-index:50;background:rgba(255,255,255,.82);backdrop-filter:saturate(180%) blur(14px);border-bottom:1px solid var(--line)}
.header-inner{display:flex;align-items:center;gap:18px;height:68px}
.logo{font-weight:800;font-size:21px;letter-spacing:-.02em;color:var(--text);display:flex;align-items:center;gap:10px}
.logo .dot{width:30px;height:30px;border-radius:9px;background:linear-gradient(135deg,var(--accent),var(--accent-2));display:inline-grid;place-items:center;color:#fff;font-weight:900;font-size:15px;box-shadow:var(--shadow-sm)}
.nav{display:flex;gap:26px;margin-left:auto;align-items:center}
.nav a{color:var(--muted);font-size:15px;font-weight:600}
.nav a:hover{color:var(--text)}
.lang-toggle{display:flex;border:1px solid var(--line);border-radius:999px;overflow:hidden;background:var(--surface)}
.lang-toggle button{background:transparent;color:var(--muted);border:0;padding:7px 13px;cursor:pointer;font-size:13px;font-weight:700}
.lang-toggle button.active{background:linear-gradient(135deg,var(--accent),var(--accent-2));color:#fff}
.menu-btn{display:none;background:none;border:0;color:var(--text);font-size:24px;cursor:pointer}

/* ===== Hero ===== */
.hero{position:relative;overflow:hidden;padding:78px 0 56px;text-align:center}
.hero::before{content:"";position:absolute;inset:0;background:
  radial-gradient(60% 60% at 15% 0%, rgba(79,70,229,.12), transparent 60%),
  radial-gradient(50% 50% at 90% 10%, rgba(124,58,237,.12), transparent 60%),
  radial-gradient(40% 40% at 50% 100%, rgba(14,165,233,.10), transparent 60%);
  pointer-events:none}
.hero .wrap{position:relative}
.hero-badge{display:inline-flex;align-items:center;gap:8px;font-size:13px;font-weight:700;color:var(--accent);background:rgba(79,70,229,.08);border:1px solid rgba(79,70,229,.18);padding:7px 15px;border-radius:999px;margin-bottom:22px}
.hero-badge .dot{width:7px;height:7px;border-radius:50%;background:var(--good);box-shadow:0 0 0 4px rgba(16,185,129,.18)}
.hero h1{font-size:clamp(34px,5vw,56px);line-height:1.08;margin:0 0 18px;font-weight:850;letter-spacing:-.03em}
.hero h1 .g{background:linear-gradient(120deg,var(--accent),var(--accent-2));-webkit-background-clip:text;background-clip:text;color:transparent}
.hero p{font-size:19px;color:var(--muted);max-width:700px;margin:0 auto 30px;line-height:1.65}
.cta-row{display:flex;gap:14px;justify-content:center;flex-wrap:wrap}
.btn{display:inline-flex;align-items:center;gap:9px;padding:13px 24px;border-radius:999px;font-weight:700;font-size:15px;border:1px solid transparent;cursor:pointer;box-shadow:var(--shadow-sm);transition:transform .15s,box-shadow .15s}
.btn:hover{transform:translateY(-2px);box-shadow:var(--shadow)}
.btn-primary{background:linear-gradient(135deg,var(--accent),var(--accent-2));color:#fff}
.btn-ghost{background:var(--surface);color:var(--text);border-color:var(--line)}
.btn-sm{padding:9px 16px;font-size:14px}

/* ===== Sections ===== */
.section{padding:54px 0}
.eyebrow{font-size:13px;font-weight:800;letter-spacing:.12em;text-transform:uppercase;color:var(--accent);margin:0 0 8px}
.section h2{font-size:clamp(26px,3.4vw,34px);margin:0 0 8px}
.section .sub{color:var(--muted);margin:0 0 30px;font-size:17px;max-width:680px}
.grid{display:grid;gap:22px}
.grid.cols-3{grid-template-columns:repeat(3,1fr)}
.grid.cols-2{grid-template-columns:repeat(2,1fr)}
.grid.cols-4{grid-template-columns:repeat(4,1fr)}

/* ===== Tool card ===== */
.card{background:var(--surface);border:1px solid var(--line);border-radius:var(--radius);padding:24px;transition:transform .18s,box-shadow .18s,border-color .18s;box-shadow:var(--shadow-sm);display:block;height:100%}
.card:hover{transform:translateY(-4px);box-shadow:var(--shadow);border-color:#d6dcff}
.card .cat{display:inline-block;font-size:12px;color:var(--accent);background:rgba(79,70,229,.08);padding:4px 11px;border-radius:999px;margin-bottom:12px;font-weight:700}
.card h3{margin:0 0 8px;font-size:21px}
.card .desc{color:var(--muted);font-size:14.5px;margin:0 0 16px}
.card .more{display:inline-flex;align-items:center;gap:6px;font-size:14px;font-weight:700;color:var(--accent)}
.card:hover .more{gap:10px}
.rating{color:var(--star);font-size:15px;letter-spacing:2px;font-weight:700}
.rating .num{color:var(--text);font-weight:800;margin-left:8px;letter-spacing:0;font-size:15px}
.tag-row{display:flex;flex-wrap:wrap;gap:7px;margin-top:14px}
.tag{font-size:12px;color:var(--muted);border:1px solid var(--line);padding:3px 10px;border-radius:999px;background:var(--surface-2)}

/* Category pills */
.pills{display:flex;flex-wrap:wrap;gap:10px;margin-bottom:28px}
.pill{font-size:14px;padding:8px 17px;border-radius:999px;border:1px solid var(--line);color:var(--muted);cursor:pointer;background:var(--surface);font-weight:600;transition:.15s}
.pill:hover{border-color:#d6dcff;color:var(--text)}
.pill.active{background:linear-gradient(135deg,var(--accent),var(--accent-2));color:#fff;border-color:transparent;box-shadow:var(--shadow-sm)}

/* Use-case card (home) */
.usecase{background:var(--surface);border:1px solid var(--line);border-radius:var(--radius);padding:26px;box-shadow:var(--shadow-sm);transition:transform .18s,box-shadow .18s}
.usecase:hover{transform:translateY(-4px);box-shadow:var(--shadow)}
.usecase .ico{width:46px;height:46px;border-radius:12px;display:grid;place-items:center;font-size:24px;background:linear-gradient(135deg,rgba(79,70,229,.12),rgba(124,58,237,.12));margin-bottom:14px}
.usecase h3{font-size:19px;margin:0 0 8px}
.usecase p{color:var(--muted);font-size:14.5px;margin:0 0 14px}
.usecase a{font-weight:700;font-size:14px}

/* Trust row */
.trust{display:flex;gap:14px;flex-wrap:wrap;justify-content:center;margin-top:34px}
.trust .t{display:flex;align-items:center;gap:10px;background:var(--surface);border:1px solid var(--line);border-radius:999px;padding:10px 18px;font-weight:600;font-size:14px;box-shadow:var(--shadow-sm)}
.trust .t .ico{width:30px;height:30px;border-radius:50%;display:grid;place-items:center;background:rgba(16,185,129,.12);color:var(--good);font-weight:900}

/* ===== Article ===== */
.article{max-width:840px;margin:0 auto;padding:48px 22px 80px}
.article .crumb{color:var(--muted);font-size:14px;margin-bottom:20px}
.article .crumb a{color:var(--muted);font-weight:600}
.article .crumb a:hover{color:var(--accent)}
.article h1{font-size:clamp(30px,4.5vw,42px);margin:0 0 12px;line-height:1.12}
.article .badge{display:inline-block;font-size:12px;font-weight:700;padding:4px 12px;border-radius:999px;background:rgba(79,70,229,.1);color:var(--accent);margin-left:10px;vertical-align:middle}
.article .meta{color:var(--muted);font-size:14px;margin-bottom:28px;display:flex;gap:18px;flex-wrap:wrap;align-items:center}
.article .meta .rating .num{font-size:15px}
.article h2{font-size:26px;margin:40px 0 14px;padding-top:6px}
.article h3{font-size:20px;margin:28px 0 10px}
.article p{margin:0 0 17px;color:#334155}
.article ul,.article ol{margin:0 0 18px;padding-left:24px;color:#334155}
.article li{margin:7px 0}
.article .lead{font-size:19px;color:var(--text);line-height:1.7}
.pros-cons{display:grid;grid-template-columns:1fr 1fr;gap:18px;margin:26px 0}
.pros-cons .box{background:var(--surface);border:1px solid var(--line);border-radius:14px;padding:20px;box-shadow:var(--shadow-sm)}
.pros-cons h4{margin:0 0 12px;font-size:17px;display:flex;align-items:center;gap:8px}
.pros-box h4{color:var(--good)}
.cons-box h4{color:var(--warn)}
.pros-cons ul{padding-left:20px;color:#475569}
.callout{background:linear-gradient(135deg,rgba(79,70,229,.08),rgba(124,58,237,.08));border:1px solid rgba(79,70,229,.2);border-radius:14px;padding:20px 22px;margin:28px 0;font-size:16.5px}
.callout b{color:var(--accent)}
table.tbl{width:100%;border-collapse:collapse;margin:20px 0;font-size:15px;overflow:hidden;border-radius:12px;box-shadow:var(--shadow-sm)}
table.tbl th,table.tbl td{border:1px solid var(--line);padding:12px 14px;text-align:left}
table.tbl th{background:var(--surface-2);color:var(--text);font-weight:700}
table.tbl tr:nth-child(even) td{background:var(--surface-2)}
.related{display:grid;grid-template-columns:repeat(3,1fr);gap:16px;margin-top:20px}

/* ===== Ad slot ===== */
.ad-slot{margin:34px 0;border:1px dashed var(--line);border-radius:14px;background:var(--surface-2);text-align:center;padding:30px 14px;color:var(--muted);font-size:13px}
.ad-slot .label{font-size:11px;letter-spacing:1.5px;text-transform:uppercase;opacity:.7;margin-bottom:8px;font-weight:700}

/* ===== Footer ===== */
.site-footer{border-top:1px solid var(--line);background:var(--surface);padding:48px 0 30px;margin-top:50px}
.footer-grid{display:grid;grid-template-columns:1.6fr 1fr 1fr 1fr;gap:30px}
.footer-grid h4{font-size:15px;margin:0 0 14px;color:var(--text)}
.footer-grid a{display:block;color:var(--muted);font-size:14px;margin:8px 0;font-weight:500}
.footer-grid a:hover{color:var(--accent)}
.footer-about{color:var(--muted);font-size:14px;margin-top:12px;line-height:1.6;max-width:340px}
.footer-bottom{border-top:1px solid var(--line);margin-top:34px;padding-top:22px;color:var(--muted);font-size:13px;text-align:center}

/* ===== Cookie banner ===== */
.cookie-banner{position:fixed;left:0;right:0;bottom:0;z-index:100;background:rgba(255,255,255,.97);backdrop-filter:blur(10px);border-top:1px solid var(--line);box-shadow:0 -10px 40px -18px rgba(15,23,42,.3);padding:18px 22px;display:flex;gap:16px;align-items:center;flex-wrap:wrap}
.cookie-banner p{margin:0;font-size:14px;color:var(--muted);flex:1;min-width:240px;line-height:1.6}
.cookie-banner a{color:var(--accent);font-weight:600}
.cookie-banner .acts{display:flex;gap:10px}
.cookie-banner button{padding:10px 20px;border-radius:999px;border:0;cursor:pointer;font-weight:700;font-size:14px}
.cookie-accept{background:linear-gradient(135deg,var(--accent),var(--accent-2));color:#fff}
.cookie-decline{background:var(--surface);border:1px solid var(--line)!important;color:var(--text)}

/* ===== Responsive ===== */
@media(max-width:980px){
  .grid.cols-4{grid-template-columns:repeat(2,1fr)}
  .grid.cols-3{grid-template-columns:repeat(2,1fr)}
  .footer-grid{grid-template-columns:1fr 1fr}
  .related{grid-template-columns:1fr 1fr}
}
@media(max-width:680px){
  .nav{display:none;position:absolute;top:68px;left:0;right:0;background:var(--surface);flex-direction:column;padding:18px 22px;border-bottom:1px solid var(--line);box-shadow:var(--shadow)}
  .nav.open{display:flex}
  .menu-btn{display:block;margin-left:auto}
  .hero{padding:54px 0 40px}
  .grid.cols-3,.grid.cols-2,.grid.cols-4{grid-template-columns:1fr}
  .pros-cons{grid-template-columns:1fr}
  .related{grid-template-columns:1fr}
  .footer-grid{grid-template-columns:1fr}
  .article .meta{gap:10px}
}

/* ---- FAQ accordion ---- */
.faq{margin:18px 0 6px;border-top:1px solid var(--line)}
.faq-item{padding:16px 0;border-bottom:1px solid var(--line)}
.faq-item h4{margin:0 0 6px;font-size:15.5px;line-height:1.5;color:var(--text);font-weight:700}
.faq-item p{margin:0;color:var(--muted);font-size:14.5px;line-height:1.75}

/* ---- code blocks (shared, not language-specific) ---- */
.code{background:#0f172a;color:#e2e8f0;border-radius:12px;padding:16px 18px;overflow-x:auto;margin:14px 0;font-size:13.5px;line-height:1.7;border:1px solid #1e293b}
.code code{font-family:ui-monospace,SFMono-Regular,Menlo,Consolas,"Courier New",monospace;white-space:pre-wrap;word-break:break-word}
.article h3{font-size:17px;margin:20px 0 8px;color:var(--text)}
.article pre:not(.code){background:#0f172a;color:#e2e8f0;padding:14px 16px;border-radius:10px;overflow-x:auto}
.article :not(pre)>code{background:#eef2ff;color:#3730a3;padding:1.5px 6px;border-radius:5px;font-size:13.5px;font-family:ui-monospace,Menlo,Consolas,monospace}
.article li code{background:#eef2ff;color:#3730a3;padding:1.5px 5px;border-radius:5px;font-size:13px}

/* ---- guide figure (SVG diagram) ---- */
.fig{margin:22px 0 6px;padding:0}
.fig img{width:100%;height:auto;border-radius:14px;border:1px solid var(--line);box-shadow:var(--shadow-sm);background:#fff}
.fig figcaption{margin-top:9px;font-size:12.5px;color:var(--muted);text-align:center}