/* PDFzen — shared styles. Clean, responsive, crawlable, ad-slot ready. */
:root{
  --bg:#ffffff; --fg:#1a1d24; --muted:#5b6470; --line:#e6e8ec;
  --brand:#2563eb; --brand-d:#1e40af; --soft:#f4f7fb; --accent:#0f766e;
  --max:920px; --radius:12px;
}
*{box-sizing:border-box}
html{-webkit-text-size-adjust:100%}
body{margin:0;font-family:-apple-system,BlinkMacSystemFont,"Segoe UI",Roboto,"Helvetica Neue",Arial,"PingFang SC","Microsoft YaHei",sans-serif;
  color:var(--fg);background:var(--bg);line-height:1.7;font-size:17px}
a{color:var(--brand);text-decoration:none}
a:hover{text-decoration:underline}
.wrap{max-width:var(--max);margin:0 auto;padding:0 18px}
header.site{border-bottom:1px solid var(--line);background:var(--soft)}
header.site .wrap{display:flex;align-items:center;justify-content:space-between;padding:14px 18px}
.github-banner{background:linear-gradient(90deg,var(--brand),var(--brand-d));color:#fff;font-size:14px;text-align:center;padding:9px 18px;line-height:1.5}
.github-banner a{color:#fff;font-weight:600;text-decoration:underline}
.github-banner .gh-star{margin-right:6px}
.logo{font-weight:800;font-size:20px;color:var(--fg);letter-spacing:-.3px}
.logo span{color:var(--brand)}
nav.top a{margin-left:18px;font-size:15px;color:var(--muted)}
.hero{padding:40px 0 26px;text-align:center}
.hero h1{font-size:34px;line-height:1.25;margin:0 0 12px;letter-spacing:-.5px}
.hero p{color:var(--muted);max-width:620px;margin:0 auto;font-size:18px}
.grid{display:grid;grid-template-columns:repeat(auto-fill,minmax(230px,1fr));gap:14px;margin:26px 0}
.card{border:1px solid var(--line);border-radius:var(--radius);padding:16px 18px;background:#fff;transition:.15s}
.card:hover{border-color:var(--brand);box-shadow:0 4px 16px rgba(37,99,235,.08)}
.card h3{margin:0 0 6px;font-size:17px}
.card p{margin:0;color:var(--muted);font-size:14px}
.cats{display:grid;grid-template-columns:repeat(auto-fill,minmax(190px,1fr));gap:12px;margin:26px 0}
.cat{display:block;border:1px solid var(--line);border-radius:var(--radius);padding:16px 18px;background:#fff;transition:.15s}
.cat:hover{border-color:var(--brand);box-shadow:0 4px 16px rgba(37,99,235,.08)}
.cat h3{margin:0 0 4px;font-size:17px}
.cat p{margin:0;color:var(--muted);font-size:13px}
.sec-h{margin:34px 0 4px;font-size:22px;letter-spacing:-.3px}
.new{display:inline-block;background:var(--accent);color:#fff;font-size:11px;font-weight:600;padding:1px 6px;border-radius:6px;vertical-align:middle;margin-left:5px}
article.page{padding:30px 0 10px}
article.page h1{font-size:30px;line-height:1.3;margin:0 0 10px;letter-spacing:-.4px}
.meta{color:var(--muted);font-size:14px;margin-bottom:18px}
.lead{font-size:19px;color:#2b313b}
h2{font-size:23px;margin:34px 0 10px;letter-spacing:-.3px}
h3{font-size:19px;margin:24px 0 8px}
p{margin:12px 0}
ul,ol{margin:12px 0;padding-left:22px}
li{margin:6px 0}
code,kbd{background:var(--soft);border:1px solid var(--line);border-radius:6px;padding:1px 6px;font-size:14px}
.answer{background:var(--soft);border:1px solid var(--line);border-left:4px solid var(--brand);border-radius:10px;padding:14px 16px;margin:18px 0}
.answer strong{color:var(--brand-d)}
table{border-collapse:collapse;width:100%;margin:18px 0;font-size:15px}
th,td{border:1px solid var(--line);padding:9px 12px;text-align:left}
th{background:var(--soft);font-weight:700}
.steps{counter-reset:step}
.steps li{list-style:none;position:relative;padding:10px 0 10px 46px;margin:8px 0;border-bottom:1px dashed var(--line)}
.steps li:before{counter-increment:step;content:counter(step);position:absolute;left:0;top:10px;width:30px;height:30px;border-radius:50%;
  background:var(--brand);color:#fff;font-weight:700;display:flex;align-items:center;justify-content:center}
/* AdSense slot — hidden until a real ad is loaded by js/ads.js (avoids showing an empty placeholder box) */
.ad-slot{display:none}
.ad-slot.has-ad{display:flex;margin:26px 0;padding:14px;border:1px dashed #c9d2e0;background:#fbfcfe;border-radius:10px;text-align:center;color:#9aa4b2;font-size:13px;min-height:90px;align-items:center;justify-content:center}
.ad-slot small{display:none}
.related{margin:34px 0;padding-top:18px;border-top:1px solid var(--line)}
.related h2{margin-top:0}
.related-hub{margin:0 0 8px}
.related-hub a{font-weight:700;color:var(--accent);text-decoration:none}
.related-hub a:hover{text-decoration:underline}
.related-spokes{margin:0;font-size:15px;color:var(--muted)}
.related-spokes a{color:var(--fg)}
.hub-list{margin:22px 0}
.hub-list ul{list-style:none;padding:0;margin:0;display:grid;grid-template-columns:1fr 1fr;gap:10px 22px}
.hub-list li{padding:10px 12px;border:1px solid var(--line);border-radius:var(--radius);background:#fff;font-size:15px;line-height:1.45}
.hub-list li a{font-weight:600;color:var(--accent);text-decoration:none}
.hub-list li a:hover{text-decoration:underline}
.hub-list li span{display:block;color:var(--muted);font-size:13.5px;margin-top:3px}
@media(max-width:600px){.hub-list ul{grid-template-columns:1fr}}
.tags{margin:10px 0 0}
.tags a{display:inline-block;background:var(--soft);border:1px solid var(--line);border-radius:999px;padding:4px 12px;font-size:13px;margin:4px 6px 0 0;color:var(--muted)}
footer.site{border-top:1px solid var(--line);margin-top:40px;padding:24px 0;color:var(--muted);font-size:14px;text-align:center}
.breadcrumb{font-size:14px;color:var(--muted);margin:18px 0 0}
.breadcrumb a{color:var(--muted)}
.pillar-note{background:#fffaf0;border:1px solid #f3e2bf;border-radius:10px;padding:12px 16px;color:#7a5b12;font-size:15px;margin:18px 0}
.about-author{margin:34px 0;padding:18px 20px;border:1px solid var(--line);border-radius:12px;background:var(--soft)}
.about-author h2{margin-top:0;font-size:20px}
.about-author p{color:var(--muted);font-size:15px;margin:10px 0}
.about-author a{font-weight:600}
footer.site a{color:var(--brand)}
/* Tool widget — in-browser PDF toolkit embedded above tutorials */
.tool-embed{margin:22px 0 6px}
.tool-embed h2{margin:0 0 12px;font-size:22px}
.tool-widget-box{border:1px solid var(--line);border-radius:var(--radius);background:linear-gradient(180deg,#f7faff,#fff);padding:18px 18px 16px;box-shadow:0 2px 10px rgba(37,99,235,.06)}
.tw-banner{font-size:14px;color:var(--muted);margin-bottom:12px;line-height:1.55}
.tw-row{display:flex;flex-wrap:wrap;gap:12px;align-items:center;margin-bottom:12px}
.tw-input{flex:1 1 220px;font-size:14px;padding:9px 10px;border:1px solid var(--line);border-radius:8px;background:#fff;min-width:200px}
.tw-field{display:inline-flex;flex-direction:column;font-size:13px;color:var(--muted);gap:4px}
.tw-field span{font-size:12px;opacity:.85}
.tw-field input,.tw-field select{font-size:14px;padding:7px 9px;border:1px solid var(--line);border-radius:8px;background:#fff;color:var(--fg)}
.tw-btn{background:var(--brand);color:#fff;border:0;border-radius:9px;padding:11px 20px;font-size:15px;font-weight:600;cursor:pointer;transition:.15s}
.tw-btn:hover{background:var(--brand-d)}
.tw-status{margin-top:12px;font-size:14px;min-height:18px;color:var(--muted)}
.tw-status.tw-ok{color:var(--accent);font-weight:600}
.tw-status.tw-error{color:#c0392b;font-weight:600}
@media(max-width:600px){.hero h1{font-size:27px}.grid{grid-template-columns:1fr 1fr}
  .tool-widget-box{padding:14px}.tw-input{flex:1 1 100%}}
/* first-hand experience block (E-E-A-T) */
.firsthand{margin:26px 0;padding:18px 20px;background:var(--soft);border:1px solid var(--line);border-left:4px solid var(--accent);border-radius:var(--radius)}
.firsthand h2{margin:0 0 8px;font-size:21px;letter-spacing:-.2px}
.firsthand p{margin:0 0 10px;color:var(--fg)}
.firsthand p:last-child{margin:0}
.firsthand .fh-note{font-size:15px;color:var(--muted)}
.firsthand .fh-note strong{color:var(--accent)}
/* PDF File Analyzer widget */
.analyzer{margin:18px 0;border:1px solid var(--line);border-radius:var(--radius);background:linear-gradient(180deg,#f7faff,#fff);padding:20px}
.drop{border:2px dashed #c2cddd;border-radius:12px;padding:34px 18px;text-align:center;color:var(--muted);font-size:16px;background:#fff;transition:.15s;cursor:pointer}
.drop.drag{border-color:var(--brand);background:#eef4ff}
.drop .browse{color:var(--brand);font-weight:700;cursor:pointer;text-decoration:underline}
.hint{font-size:13px;color:#9aa4b2;text-align:center;margin:10px 0 0}
.result{margin-top:16px}
.res-grid{display:grid;grid-template-columns:repeat(auto-fit,minmax(140px,1fr));gap:12px}
.res-grid > div{border:1px solid var(--line);border-radius:10px;padding:14px;background:#fff;text-align:center}
.res-grid .rl{display:block;font-size:13px;color:var(--muted);margin-bottom:6px}
.res-grid .rv{display:block;font-size:20px;font-weight:800;color:var(--fg)}
.res-note{margin:12px 0 0;font-size:14px;color:var(--accent);background:var(--soft);border-radius:8px;padding:10px 12px}

/* ===== Rebuilt tool widget (P0) — dropzone + file list + progress + privacy pill ===== */
.tool-embed{margin:8px 0 26px}
.tool-embed h2{margin:0 0 14px;font-size:22px}
.tool-widget-box{border:1px solid var(--line);border-radius:14px;background:linear-gradient(180deg,#f7faff,#fff);padding:20px 20px 18px;box-shadow:0 4px 22px rgba(37,99,235,.09)}
.tw-privacy{display:inline-flex;align-items:center;gap:7px;background:rgba(15,118,110,.10);color:var(--accent);border:1px solid rgba(15,118,110,.25);border-radius:999px;padding:6px 13px;font-size:13.5px;font-weight:600;margin-bottom:14px}
.tw-lock{font-size:14px;line-height:1}
.tw-banner{font-size:14.5px;color:var(--muted);margin-bottom:14px;line-height:1.55}
.tw-drop{border:2px dashed #c2cddd;border-radius:12px;padding:30px 18px;text-align:center;background:#fff;cursor:pointer;position:relative;overflow:hidden;transition:border-color .15s,background .15s}
.tw-file{position:absolute;inset:0;width:100%;height:100%;opacity:0;font-size:0;cursor:pointer}
.tw-drop:hover,.tw-drop.tw-drag{border-color:var(--brand);background:#eef4ff}
.tw-drop-inner{display:flex;flex-direction:column;align-items:center;gap:4px;pointer-events:none}
.tw-drop-icon{font-size:26px;margin-bottom:2px}
.tw-drop-text{font-size:16px;color:var(--fg)}
.tw-browse{color:var(--brand);font-weight:700;text-decoration:underline}
.tw-formats{font-size:12.5px;color:#9aa4b2;margin-top:2px}
.tw-files{margin:14px 0 0;border-top:1px solid var(--line);padding-top:12px}
.tw-file-count{font-size:13px;font-weight:600;color:var(--muted);margin-bottom:8px}
.tw-file-row{display:flex;align-items:center;gap:10px;padding:6px 0;border-bottom:1px dashed var(--line);font-size:14px}
.tw-fname{flex:1 1 auto;overflow:hidden;text-overflow:ellipsis;white-space:nowrap}
.tw-fsize{color:var(--muted);font-size:12.5px;flex:0 0 auto}
.tw-rm{flex:0 0 auto;border:0;background:#fdeceb;color:#c0392b;width:24px;height:24px;border-radius:50%;font-size:16px;line-height:1;cursor:pointer}
.tw-opts{margin:14px 0 0}
.tw-btn{margin-top:14px;background:var(--brand);color:#fff;border:0;border-radius:9px;padding:12px 22px;font-size:15px;font-weight:600;cursor:pointer;transition:background .15s}
.tw-btn:hover:not(:disabled){background:var(--brand-d)}
.tw-btn:disabled{opacity:.6;cursor:progress}
.tw-progress{margin-top:14px;height:8px;border-radius:999px;background:var(--soft);overflow:hidden}
.tw-progress.tw-active .tw-bar{width:42%;height:100%;border-radius:999px;background:linear-gradient(90deg,var(--brand),var(--accent));animation:twslide 1.1s infinite ease-in-out}
@keyframes twslide{0%{margin-left:-42%}100%{margin-left:100%}}
.tw-status{margin-top:12px;font-size:14px;min-height:18px;color:var(--muted)}
.tw-status.tw-ok{color:var(--accent);font-weight:600}
.tw-status.tw-error{color:#c0392b;font-weight:600}
.tw-shake{animation:twshake .42s}
@keyframes twshake{0%,100%{transform:translateX(0)}25%{transform:translateX(-6px)}75%{transform:translateX(6px)}}
@media(max-width:600px){.tool-widget-box{padding:16px}.tw-drop{padding:24px 14px}}

/* 升级批次(2026-08-15): 对比表 + 首页信任条 */
table.cmp{width:100%;border-collapse:collapse;margin:16px 0;font-size:14.5px;background:var(--card);border:1px solid var(--line);border-radius:10px;overflow:hidden}
table.cmp th,table.cmp td{padding:10px 12px;text-align:left;border-bottom:1px solid var(--line);vertical-align:top}
table.cmp thead th{background:var(--soft);font-weight:700}
table.cmp tbody tr:last-child td{border-bottom:0}
table.cmp td:first-child{font-weight:600;color:var(--fg);white-space:nowrap}
.trust-strip{display:flex;flex-wrap:wrap;gap:10px;margin:18px 0 4px}
.trust-strip .pill{background:var(--soft);border:1px solid var(--line);border-radius:999px;padding:7px 14px;font-size:13.5px;font-weight:600;color:var(--accent)}
.trust-strip .pill b{color:var(--brand)}

/* ===== PWA install bar (分发引擎①: 可安装 / 可离线 / 自有分发面) ===== */
#pwa-install{position:fixed;left:50%;bottom:18px;transform:translateX(-50%);z-index:60;display:flex;align-items:center;gap:12px;background:var(--brand);color:#fff;padding:10px 14px;border-radius:999px;box-shadow:0 10px 30px rgba(37,99,235,.35);font-size:14px;max-width:92vw;line-height:1.4}
#pwa-install[hidden]{display:none}
#pwa-install b{font-weight:700}
#pwa-install .pi-btn{background:#fff;color:var(--brand);border:0;border-radius:999px;padding:6px 14px;font-weight:700;cursor:pointer;font-size:13px;white-space:nowrap}
#pwa-install .pi-btn:hover{background:#eef4ff}
#pwa-install .pi-x{background:transparent;border:0;color:#fff;font-size:20px;line-height:1;cursor:pointer;opacity:.8;padding:0 2px}
#pwa-install .pi-x:hover{opacity:1}
@media(max-width:600px){#pwa-install{flex-wrap:wrap;justify-content:center;bottom:10px;font-size:13px}}