:root{--bg:#f6f8fa;--panel:#fff;--ink:#151a21;--muted:#5a6573;--line:#dce1e8;--grid:#edf0f4;--accent:#0b7285;--accent-2:#095c6b;--accent-soft:#e3f1f4;--warm:#f08c00;
--f-display:"Bricolage Grotesque",ui-sans-serif,system-ui,sans-serif;--f-body:"Instrument Sans",ui-sans-serif,system-ui,-apple-system,"Apple SD Gothic Neo","Malgun Gothic","PingFang SC","Hiragino Sans GB","Microsoft YaHei",sans-serif;--r:14px}
*{box-sizing:border-box}
html{-webkit-text-size-adjust:100%}
body{margin:0;background:var(--bg);color:var(--ink);font:16px/1.65 var(--f-body)}
a{color:var(--accent)}
img,svg{max-width:100%}
.wrap{max-width:1160px;margin:0 auto;padding:0 20px}
.narrow>*{max-width:820px}
.skip{position:absolute;left:-999px;top:8px;background:var(--ink);color:#fff;padding:8px 12px;border-radius:8px;z-index:10}.skip:focus{left:8px}
.vh{position:absolute;width:1px;height:1px;overflow:hidden;clip:rect(0 0 0 0);white-space:nowrap}

/* header */
.top{background:var(--panel);border-bottom:1px solid var(--line);position:sticky;top:0;z-index:5}
.top-in{display:flex;align-items:center;gap:20px;min-height:60px}
.logo{display:inline-flex;align-items:center;gap:8px;font:700 19px/1 var(--f-display);color:var(--ink);text-decoration:none;flex:none}.logo svg{width:24px;height:24px}
.main{display:flex;gap:2px;overflow-x:auto;scrollbar-width:none;flex:1;min-width:0}
.main a{white-space:nowrap;padding:7px 11px;border-radius:999px;color:var(--muted);text-decoration:none;font-size:14.5px;font-weight:500}
.main a:hover{color:var(--ink);background:var(--bg)}.main a[aria-current]{color:var(--accent);background:var(--accent-soft)}
.langs{display:flex;border:1px solid var(--line);border-radius:999px;padding:2px;flex:none}
.langs a{padding:4px 10px;border-radius:999px;font-size:13px;color:var(--muted);text-decoration:none}.langs a[aria-current]{background:var(--ink);color:#fff}
@media (max-width:820px){.top-in{flex-wrap:wrap;gap:8px 12px;padding:8px 0}.main{order:3;flex-basis:100%;margin:0 -20px;padding:0 14px}.langs{margin-left:auto}}

/* hero */
.hero{padding:44px 20px 18px}
.crumbs{font-size:13.5px;color:var(--muted);margin-bottom:10px}.crumbs a{color:var(--muted)}
h1{font:700 clamp(32px,5vw,52px)/1.08 var(--f-display);letter-spacing:-.02em;margin:0 0 14px;max-width:900px}
.lead{font-size:clamp(16.5px,2vw,19px);color:var(--muted);margin:0;max-width:760px}
.badges{display:flex;flex-wrap:wrap;gap:8px;list-style:none;padding:0;margin:18px 0 0}
.badges li{font-size:13.5px;font-weight:600;color:var(--accent);background:var(--accent-soft);padding:5px 12px;border-radius:999px}

/* tool */
.tool{margin-top:16px;scroll-margin-top:80px}
.stage{display:grid;grid-template-columns:minmax(0,1fr) minmax(0,1.15fr);gap:18px;background:var(--panel);border:1px solid var(--line);border-radius:20px;padding:18px;box-shadow:0 10px 30px -18px rgba(21,26,33,.25)}
.drop{border:2px dashed #b7c8d0;border-radius:var(--r);display:flex;flex-direction:column;align-items:center;justify-content:center;text-align:center;gap:10px;padding:34px 20px;background:linear-gradient(180deg,#fbfdfe,#f1f7f9);transition:border-color .15s,background .15s;min-height:300px}
.tool.over .drop{border-color:var(--accent);background:var(--accent-soft)}
.drop-ic{width:46px;height:46px;color:var(--accent)}
.drop-t{font:700 21px/1.25 var(--f-display);margin:0}
.btn{display:inline-flex;align-items:center;justify-content:center;gap:6px;border-radius:999px;padding:12px 26px;font:600 16px/1 var(--f-body);cursor:pointer;text-decoration:none;border:0}
.btn.primary{background:var(--accent);color:#fff}.btn.primary:hover{background:var(--accent-2)}
#sg-file:focus-visible+.drop-alt,.btn:focus-visible{outline:3px solid #99c9d3;outline-offset:2px}
.drop-alt{display:flex;gap:8px;align-items:center;flex-wrap:wrap;justify-content:center;color:var(--muted);font-size:14.5px}
.link{background:none;border:0;padding:2px;color:var(--accent);font:600 14.5px var(--f-body);cursor:pointer;text-decoration:underline;text-underline-offset:3px}
.drop-f{margin:0;font-size:13px;color:var(--muted)}
.drop-p{display:flex;align-items:center;gap:6px;margin:0;font-size:13px;color:var(--muted)}
.ex{margin:0;display:flex;flex-direction:column;gap:6px}
.ex-svg{display:block;width:100%;height:auto;border:1px solid var(--grid);border-radius:12px}
.ex figcaption{font-size:12.5px;color:var(--muted);text-align:right}
.tool.live .stage{display:block;padding:0;overflow:hidden}
.tool iframe.app{display:block;width:100%;height:860px;border:0;background:var(--bg)}
.tool .loading{padding:120px 20px;text-align:center;color:var(--muted)}
@media (max-width:860px){.stage{grid-template-columns:1fr}.drop{min-height:240px}}
.note{color:var(--muted);font-size:14px}

/* sections */
.block{padding:56px 20px 8px}
h2{font:700 clamp(24px,3vw,32px)/1.2 var(--f-display);letter-spacing:-.01em;margin:0 0 16px}
h3{font-size:17px;margin:0 0 6px}
.sub{color:var(--muted);margin:-6px 0 22px;max-width:720px}
.steps{counter-reset:s;list-style:none;padding:0;margin:0;display:grid;gap:12px}
.steps li{counter-increment:s;position:relative;padding:14px 16px 14px 58px;background:var(--panel);border:1px solid var(--line);border-radius:12px}
.steps li::before{content:counter(s);position:absolute;left:16px;top:13px;width:28px;height:28px;border-radius:50%;background:var(--accent);color:#fff;font-weight:700;display:grid;place-items:center;font-size:14px}
.hub{display:grid;grid-template-columns:repeat(auto-fill,minmax(250px,1fr));gap:16px}
.hub-card{display:flex;flex-direction:column;gap:6px;background:var(--panel);border:1px solid var(--line);border-radius:16px;padding:14px;text-decoration:none;color:var(--ink);transition:transform .15s,box-shadow .15s,border-color .15s}
.hub-card:hover{transform:translateY(-2px);border-color:#99c9d3;box-shadow:0 12px 26px -18px rgba(11,114,133,.55)}
.hub-card .thumb{display:block;border-radius:10px;overflow:hidden;background:#fff;margin-bottom:6px}
.hub-card .thumb .ex-svg{border:0;border-radius:0}
.hub-card strong{font:700 18px/1.3 var(--f-display)}.hub-card span:last-child{color:var(--muted);font-size:14.5px}
.trio{display:grid;grid-template-columns:repeat(3,1fr);gap:16px}.quad{display:grid;grid-template-columns:repeat(4,1fr);gap:16px}
@media (max-width:960px){.quad{grid-template-columns:repeat(2,1fr)}}
@media (max-width:760px){.trio,.quad{grid-template-columns:1fr}}
.tile{display:block;background:var(--panel);border:1px solid var(--line);border-radius:14px;padding:18px;color:var(--ink);text-decoration:none}
.tile p{margin:0;color:var(--muted);font-size:15px}

/* article */
.article{display:grid;grid-template-columns:1fr;gap:20px;padding-top:56px}
.toc{background:var(--panel);border:1px solid var(--line);border-radius:12px;padding:14px 18px;font-size:14.5px}
.toc ol{margin:6px 0 0;padding-left:20px;columns:2;column-gap:28px}.toc li{margin:3px 0;break-inside:avoid}
@media (max-width:640px){.toc ol{columns:1}}
.prose section{scroll-margin-top:80px}
.prose h2{margin-top:44px}.prose section:first-child h2{margin-top:8px}
.prose p,.prose li{max-width:72ch}
.prose ul,.prose ol{padding-left:22px}.prose li{margin:6px 0}
.prose code{background:#eef2f5;border-radius:5px;padding:1px 5px;font-size:.92em}
.cmp{width:100%;border-collapse:collapse;margin:16px 0;font-size:15px;background:var(--panel);border:1px solid var(--line);border-radius:12px;overflow:hidden}
.cmp th,.cmp td{padding:10px 14px;border-bottom:1px solid var(--grid);text-align:left;vertical-align:top}
.cmp thead th{background:var(--bg);font-size:13.5px;color:var(--muted)}
.cmp tbody tr:last-child td{border-bottom:0}
.meta{color:var(--muted);font-size:13.5px}
.faq details{background:var(--panel);border:1px solid var(--line);border-radius:12px;margin:0 0 10px;padding:0 18px}
.faq summary{cursor:pointer;font-weight:600;padding:14px 0;list-style:none;display:flex;justify-content:space-between;gap:12px}
.faq summary::after{content:"+";color:var(--accent);font-size:20px;line-height:1}.faq details[open] summary::after{content:"−"}
.faq summary::-webkit-details-marker{display:none}
.faq details p{margin:0 0 16px;color:var(--muted)}

/* footer */
.foot{margin-top:72px;background:var(--panel);border-top:1px solid var(--line);padding:36px 0 44px;font-size:14.5px;color:var(--muted)}
.foot-in{display:grid;grid-template-columns:1fr 1.4fr;gap:28px}
.foot-about p{margin:10px 0 0;max-width:360px}.foot a{color:var(--muted)}
.foot-tools{display:grid;grid-template-columns:repeat(2,1fr);gap:6px 20px;align-content:start}.foot-tools a{text-decoration:none}.foot-tools a:hover{color:var(--accent)}
@media (max-width:760px){.foot-in{grid-template-columns:1fr}}
html[lang=ko] body{word-break:keep-all}
@media (max-width:640px){.hero{padding-top:28px}.badges{margin-top:12px}.block{padding-top:44px}}
html[lang=zh-CN]{--f-display:"PingFang SC","Hiragino Sans GB","Microsoft YaHei",system-ui,sans-serif;--f-body:"PingFang SC","Hiragino Sans GB","Microsoft YaHei",system-ui,-apple-system,sans-serif}
html[lang=zh-CN] h1{letter-spacing:0}