.nb-dusk[data-size=page] .nb-dusk-kick{margin-top:28px}.nb-dusk[data-size=page] h1{margin-top:28px;max-width:15em;font-size:clamp(32px,4.6vw,60px);line-height:1.15;text-shadow:0 2px 20px rgba(30,20,60,.3)}:lang(zh-CN) .nb-dusk[data-size=page] h1{font-weight:900;letter-spacing:.04em}.nb-dusk[data-size=page] .nb-dusk-lede{margin-top:16px;max-width:36em;font:500 clamp(17px,1.5vw,20px)/1.7 var(--font-display)}.nb-page{padding-top:clamp(36px,5vw,64px)}.nb-read{max-width:720px;font-size:17px;line-height:1.8}.nb-read>p+p{margin-top:1em}.nb-read-lead{font:500 19px/1.7 var(--font-display)}.nb-page-sec{margin-top:clamp(36px,4vw,52px)}.nb-page-first{margin-top:0}.nb-page-sec h2,.nb-sheet h2{font-size:clamp(24px,2.4vw,30px);line-height:1.25;margin-bottom:14px}.nb-page-sec h3{font-size:19px;line-height:1.3}.nb-link,.nb-read a:not([class]){color:var(--brand-hover);text-decoration:underline;text-underline-offset:3px;overflow-wrap:anywhere}.nb-onward{color:var(--brand-hover);font-weight:600;text-decoration:underline;text-underline-offset:4px;text-decoration-thickness:1px}.nb-onward:after{content:" \2192"}.nb-onward:hover{text-decoration-thickness:2px}.nb-page-actions{display:flex;flex-wrap:wrap;align-items:center;gap:16px 28px;margin-top:40px}.nb-page-actions .nb-go{min-height:52px}.nb-steps{display:grid;gap:22px}.nb-steps li{display:grid;grid-template-columns:44px 1fr;gap:16px;align-items:start}.nb-step-num{display:inline-flex;align-items:center;justify-content:center;width:40px;height:40px;border-radius:8px 8px 8px 0;background:var(--brand);color:#fff;font:600 18px/1 var(--font-display)}.nb-steps p{color:var(--ink-muted);margin-top:2px}.nb-updated{color:var(--ink-muted);font-size:15px}.nb-toc{margin-top:24px;padding:18px 22px;background:var(--surface);border-radius:var(--r)}.nb-toc h2{font:600 15px var(--font-text);margin-bottom:8px}.nb-toc ol{margin:0;padding-left:1.4em;columns:2 220px;column-gap:32px;font-size:15px;line-height:1.9}.nb-toc a{color:var(--brand-hover);text-decoration:underline;text-underline-offset:3px}.nb-policy .nb-page-sec h2{scroll-margin-top:24px}.nb-page-split{display:grid;grid-template-columns:minmax(0,7fr) minmax(0,4fr);gap:clamp(28px,4vw,56px);align-items:start}.nb-page>.nb-page-split{margin-top:clamp(36px,4vw,52px)}.nb-page.nb-page-split,.nb-page>.nb-page-split:first-child{margin-top:0}.nb-sheet{background:var(--surface);border-radius:var(--r);padding:clamp(22px,3vw,36px);box-shadow:0 1px 2px #1e24300f,0 10px 28px -12px #1e24302e}.nb-aside{display:grid;gap:28px;padding-top:8px}.nb-aside-block h2,.nb-aside-block h3{font-size:19px;line-height:1.3;margin-bottom:6px}.nb-aside-block p{color:var(--ink-muted)}.nb-aside-block p+.nb-onward{display:inline-block;margin-top:10px}.nb-aside-block+.nb-aside-block{border-top:1px solid var(--line);padding-top:24px}.nb-ticks{display:grid;gap:8px;margin-top:10px}.nb-ticks li{position:relative;padding-left:26px}.nb-ticks li:before{content:"";position:absolute;left:2px;top:.55em;width:12px;height:7px;border:solid var(--brand);border-width:0 0 2px 2px;transform:rotate(-45deg)}@media (max-width: 900px){.nb-page-split{grid-template-columns:1fr}}.nb-trap{position:absolute;left:-9999px;width:1px;height:1px;overflow:hidden}.nb-form{display:grid;gap:18px}.nb-form-req{font-size:14px;color:var(--ink-muted)}.nb-form-pair{display:grid;grid-template-columns:1fr 1fr;gap:18px}@media (max-width: 560px){.nb-form-pair{grid-template-columns:1fr}}.nb-slot{display:flex;flex-direction:column;gap:6px;min-width:0}.nb-slot label{font-size:15px;font-weight:600}.nb-slot label span{color:var(--brand)}.nb-slot-hint{font-size:14px;color:var(--ink-muted)}.nb-slot :is(input,select,textarea){width:100%;border:1.5px solid var(--edge);border-radius:10px;background:var(--field);color:var(--ink);font:16px/1.5 var(--font-text);padding:11px 14px}.nb-slot textarea{resize:vertical;min-height:140px}.nb-slot :is(input,select,textarea):focus-visible{outline:3px solid var(--ink);outline-offset:1px}.nb-slot-error{display:none;font-size:14px;font-weight:600;color:var(--brand-hover)}.nb-slot-error:before{content:"! "}.nb-slot[data-invalid] .nb-slot-error{display:block}.nb-slot[data-invalid] :is(input,select,textarea){border-color:var(--brand);border-width:2px;background:#fff8f6}.nb-form-alert{padding:12px 16px;border-left:4px solid var(--brand);background:#fbefec;color:var(--ink);border-radius:0 8px 8px 0}.nb-form-foot{display:flex;flex-wrap:wrap;align-items:center;gap:14px 20px}.nb-form-foot .nb-go{min-height:52px}.nb-form-foot .nb-go[aria-disabled=true]{opacity:.7;cursor:progress}.nb-form-note{flex:1 1 220px;font-size:14px;color:var(--ink-muted)}.nb-form-note a{color:var(--brand-hover);text-decoration:underline;text-underline-offset:3px}.nb-sent{padding:20px 22px;border-left:4px solid var(--brand);background:var(--bg);border-radius:0 10px 10px 0}.nb-sent:focus-visible{outline:3px solid var(--ink);outline-offset:2px}.nb-sent-title{font:600 20px/1.3 var(--font-display);margin-bottom:4px}.nb-about{padding-bottom:clamp(48px,6vw,88px)}.nb-ab-intro{display:grid;grid-template-columns:minmax(0,1fr) minmax(280px,380px);gap:clamp(32px,5vw,72px);align-items:start}.nb-ledger{background:var(--surface, #FFFFFF);border:1px solid var(--rule);border-top:4px solid var(--brand);padding:22px 24px 18px}.nb-ledger h2{font-size:20px;margin-bottom:8px}.nb-ledger dl{margin:0}.nb-ledger dl div{display:flex;align-items:baseline;gap:10px;padding:10px 0}.nb-ledger dl div+div{border-top:1px solid var(--line)}.nb-ledger dt{font-size:15px;color:var(--ink-muted)}.nb-ledger dt:after{content:"";flex:1}.nb-ledger dd{margin:0 0 0 auto;font:600 26px/1 var(--font-display);color:var(--ink);font-variant-numeric:tabular-nums}.nb-ab-intro .nb-read h2{font-size:clamp(24px,2.6vw,34px);line-height:1.2;margin-bottom:14px}.nb-ab-intro .nb-read{padding-top:22px}.nb-ab-sec{margin-top:clamp(56px,7vw,96px)}.nb-ab-sec>h2,.nb-ab-close h2{font-size:clamp(24px,2.6vw,34px);line-height:1.2}.nb-rivers-map{position:relative;display:grid;grid-template-columns:minmax(0,1.1fr) minmax(0,.9fr) auto;align-items:stretch;margin-top:28px}.nb-rivers-steps{display:grid;grid-template-rows:repeat(3,1fr);gap:0;margin:0;padding:0}.nb-rivers-steps li{display:grid;grid-template-columns:44px 1fr;column-gap:16px;align-content:center;min-height:112px;padding:10px 24px 10px 0}.nb-rivers-num{grid-row:1 / 3;display:inline-grid;place-items:center;width:40px;height:40px;border-radius:50%;background:var(--sky);color:#fff;font:600 18px/1 var(--font-display)}.nb-rivers-steps h3{font-size:20px;line-height:1.3}.nb-rivers-steps p{margin-top:2px;color:var(--ink-muted);max-width:30em}.nb-rivers-art{width:100%;height:100%;overflow:visible}.nb-rivers-art path{fill:none;stroke:var(--band-low);stroke-width:3;stroke-linecap:round;vector-effect:non-scaling-stroke}.nb-rivers-art .nb-rivers-one{stroke:var(--brand);stroke-width:6}.nb-rivers-end{display:grid;place-items:center;margin:0}.nb-rivers-end span{display:inline-block;padding:12px 18px;background:var(--brand);color:#fff;font:600 17px/1.2 var(--font-display);border-radius:999px;white-space:nowrap}.nb-ab-close{display:grid;grid-template-columns:minmax(0,1fr) auto;gap:24px 48px;align-items:center;margin-top:clamp(56px,7vw,96px);padding:clamp(28px,4vw,48px);background:var(--sky);color:var(--masthead-ink);border-radius:var(--r)}.nb-ab-close h2{color:#fff}.nb-ab-close :focus-visible{outline:3px solid #FFFFFF;outline-offset:3px}@media (max-width: 900px){.nb-ab-intro{grid-template-columns:1fr}.nb-rivers-map{grid-template-columns:1fr;padding-left:20px;border-left:3px solid var(--band-low)}.nb-rivers-art{display:none}.nb-rivers-steps li{min-height:0;padding:12px 0}.nb-rivers-end{justify-items:start;margin-top:8px}.nb-ab-close{grid-template-columns:1fr}}