*{box-sizing:border-box}html{scroll-behavior:smooth;scroll-padding-top:20px}body{margin:0;color:#17324e;background:#f4f8fc;font:16px/1.85 system-ui,-apple-system,"Segoe UI","Microsoft YaHei",sans-serif}a{color:#126bb7;text-underline-offset:4px;overflow-wrap:anywhere}a:hover{color:#03477f}a:focus-visible{outline:3px solid #eeab32;outline-offset:4px}.skip{position:absolute;left:10px;top:-80px;background:white;padding:10px}.skip:focus{top:10px}header{background:white;border-bottom:1px solid #dbe7f1}.bar{max-width:1180px;margin:auto;padding:18px 28px;display:flex;align-items:center;justify-content:space-between;gap:18px}.brand{font-weight:800;font-size:24px;text-decoration:none;white-space:nowrap}.bar nav{display:flex;gap:22px;flex-wrap:wrap}.layout{max-width:1180px;margin:32px auto 70px;display:grid;grid-template-columns:minmax(0,1fr) 220px;gap:30px;padding:0 28px}article{background:white;border:1px solid #dbe7f1;border-radius:18px;min-width:0;overflow:hidden}.hero{padding:36px 36px 30px;background:linear-gradient(140deg,#f2f9ff,white);border-bottom:1px solid #dbe7f1}.crumb{font-size:14px;color:#5d7288}.crumb ol{list-style:none;display:flex;gap:9px;flex-wrap:wrap;padding:0;margin:0 0 22px}.eyebrow{font-size:13px;letter-spacing:.08em;color:#216aa2;margin-bottom:8px}h1{font-size:32px;line-height:1.45;letter-spacing:-.02em;margin:8px 0 18px}h2{font-size:23px;line-height:1.5;margin:0 0 16px}h3{font-size:18px;line-height:1.6;margin:18px 0 6px}p{margin:0 0 16px}.lead{font-size:18px}.meta{font-size:13px;color:#5d7288;margin:18px 0 0}.content{padding:0 36px 34px}.content>section{padding-top:34px;scroll-margin-top:24px}.note{padding:16px 19px;border-left:3px solid #2785cc;background:#f1f7fd;font-size:14px}.choices{border-collapse:collapse;width:100%;font-size:15px}.choices th,.choices td{padding:14px 12px;border-bottom:1px solid #dbe7f1;text-align:left;vertical-align:top}.choices th{background:#eff6fc;color:#234e74}.steps{padding-left:24px}.steps li{padding-left:6px;margin-bottom:20px}.steps h3{margin:0 0 6px}.steps p{margin:0}.sample{white-space:pre-wrap;overflow-wrap:anywhere;background:#f4f8fc;border:1px solid #dbe7f1;border-radius:10px;padding:20px;font-size:15px;line-height:1.9}.model{border-top:1px solid #dbe7f1;padding:16px 0}.model h3{margin:0 0 7px;font-size:17px}.model p{margin-bottom:8px}.model details{font-size:13px;color:#526c84}.model code{word-break:break-all}.model summary{cursor:pointer;color:#126bb7}.model small{color:#5d7288}.faq details{padding:16px 0;border-bottom:1px solid #dbe7f1}.faq summary{font-weight:650;cursor:pointer}.faq p{margin:12px 0 0}.related{display:flex;flex-direction:column;gap:10px}aside{align-self:start;position:sticky;top:26px;font-size:14px}aside nav{display:flex;flex-direction:column;gap:12px}aside strong{display:block;margin-bottom:16px}footer{border-top:1px solid #dbe7f1;padding:26px;text-align:center;color:#5d7288;font-size:14px}footer a{margin:0 9px}@media(max-width:850px){.layout{display:block;max-width:780px}aside{position:static;margin-top:28px}aside nav{flex-direction:row;flex-wrap:wrap}h1{font-size:28px}}@media(max-width:560px){.bar{padding:14px 18px;align-items:flex-start}.brand{font-size:22px}.bar nav{gap:8px 14px;font-size:13px;justify-content:flex-end}.layout{margin:18px auto 38px;padding:0 12px}.hero{padding:25px 21px}.content{padding:0 21px 26px}h1{font-size:25px}.lead{font-size:16px}h2{font-size:21px}.choices thead{position:absolute;clip-path:inset(50%);width:1px;height:1px;overflow:hidden}.choices tr{display:block;border:1px solid #dbe7f1;border-radius:9px;margin:12px 0;padding:10px 13px}.choices td{display:block;border:0;padding:6px 0}.choices td:before{content:attr(data-label);display:block;font-size:12px;color:#627a90}.choices td:first-child{font-weight:650}.choices td:first-child:before{font-weight:400}.sample{padding:15px}.note{padding:14px 16px}aside{padding:0 10px}}@media(prefers-reduced-motion:reduce){html{scroll-behavior:auto}} .mobile-toc{display:none}@media(max-width:850px){aside{display:none}.mobile-toc{display:block;padding:12px 21px;border-bottom:1px solid #dbe7f1}.mobile-toc summary{padding:10px 0;color:#126bb7;font-weight:650;cursor:pointer;min-height:44px}.mobile-toc nav{display:grid;grid-template-columns:1fr 1fr;gap:4px 12px;padding:8px 0 12px}.mobile-toc a{padding:8px 0;font-size:14px;line-height:1.7;min-height:42px}}