.dd-page,.dl-page{--doc-accent:#4a9bff;--doc-accent-2:#22d3ee;--doc-soft:rgba(74,155,255,0.11);--doc-line:color-mix(in srgb,var(--current-text-primary) 12%,transparent);--doc-line-strong:color-mix(in srgb,var(--current-text-primary) 22%,transparent);--doc-muted:var(--current-text-secondary);background:var(--current-bg);color:var(--current-text-primary);min-height:100vh;overflow-x:clip}[data-theme=light] .dd-page,[data-theme=light] .dl-page{--doc-accent:#1f6fe0;--doc-accent-2:#0891b2;--doc-soft:rgba(31,111,224,0.08)}.dd-container,.dl-container{width:min(1280px,calc(100% - 48px));margin-inline:auto}.dl-hero{position:relative;overflow:hidden;padding:calc(var(--header-height) + 48px) 0 0;border-bottom:1px solid var(--doc-line)}.dl-hero__grid{position:absolute;inset:0;background-image:linear-gradient(var(--doc-line) 1px,transparent 1px),linear-gradient(90deg,var(--doc-line) 1px,transparent 1px);background-size:72px 72px;opacity:.42;-webkit-mask-image:linear-gradient(180deg,black,transparent 85%);mask-image:linear-gradient(180deg,black,transparent 85%);pointer-events:none}.dl-crumbs{position:relative;z-index:2;display:flex;flex-wrap:wrap;gap:8px;color:var(--doc-muted);font-size:12px}.dl-crumbs a{color:var(--doc-muted);text-decoration:none}.dl-crumbs a:hover{color:var(--doc-accent)}.dl-hero__inner{position:relative;z-index:2;max-width:850px;padding:clamp(48px,7vw,84px) 0 clamp(38px,5vw,54px)}.dl-kicker{display:flex;align-items:center;gap:10px;margin:0 0 18px;color:var(--doc-muted);font-size:10px;font-weight:650;letter-spacing:.14em;text-transform:uppercase}.dl-kicker span{width:24px;height:1px;background:var(--doc-accent)}.dl-hero h1{margin:0;font-family:var(--font-family-chinese);font-size:clamp(42px,5.4vw,68px);font-weight:800;letter-spacing:-.045em}.dl-hero p{max-width:720px;margin:18px 0 0;color:var(--doc-muted);font-size:15px;line-height:1.85}.dl-tools{border-bottom:1px solid var(--doc-line);background:color-mix(in srgb,var(--current-surface) 38%,transparent)}.dl-tools__inner{justify-content:space-between;gap:24px;padding:18px 0}.dl-search,.dl-tools__inner{display:flex;align-items:center}.dl-search{width:min(430px,100%);gap:8px;padding:8px 12px;border:1px solid var(--doc-line-strong);border-radius:5px;background:var(--current-bg)}.dl-search:focus-within{border-color:var(--doc-accent);box-shadow:0 0 0 3px var(--doc-soft)}.dl-search svg{width:16px;height:16px;flex:0 0 auto;color:var(--doc-muted)}.dl-search input{width:100%;border:0;outline:0;background:transparent;color:var(--current-text-primary);font:inherit;font-size:12px}.dl-cats{display:flex;flex-wrap:wrap;gap:4px}.dl-cats button{display:inline-flex;align-items:center;gap:7px;padding:7px 9px;border:1px solid transparent;border-radius:4px;background:transparent;color:var(--doc-muted);font:inherit;font-size:11px;cursor:pointer}.dl-cats button span{color:var(--doc-muted);font-family:ui-monospace,monospace;font-size:9px;opacity:.7}.dl-cats button:hover{color:var(--current-text-primary);background:color-mix(in srgb,var(--current-text-primary) 5%,transparent)}.dl-cats button.is-active{color:var(--doc-accent);border-color:color-mix(in srgb,var(--doc-accent) 26%,transparent);background:var(--doc-soft)}.dl-list{padding:clamp(40px,6vw,68px) 0 clamp(64px,8vw,96px)}.dl-list__bar{display:flex;align-items:center;justify-content:space-between;gap:20px;padding-bottom:14px;border-bottom:1px solid var(--doc-line-strong);color:var(--doc-muted);font-family:ui-monospace,monospace;font-size:10px}.dl-list__bar a{color:var(--doc-muted);font-family:var(--font-family-sans);text-decoration:none}.dl-list__bar a:hover{color:var(--doc-accent)}.dl-scroll{max-height:calc(100vh - 300px);overflow-y:auto;overscroll-behavior:contain;padding-right:8px;scrollbar-width:thin;scrollbar-color:color-mix(in srgb,var(--doc-accent) 40%,transparent) transparent}.dl-grid{display:grid;grid-template-columns:repeat(3,minmax(0,1fr));gap:12px;margin-top:16px}.dl-card{display:flex;min-height:260px;flex-direction:column;padding:22px;border:1px solid var(--doc-line);border-radius:7px;background:color-mix(in srgb,var(--current-surface) 45%,transparent);color:inherit;text-decoration:none;transition:transform .3s cubic-bezier(.22,1,.36,1),border-color .25s,background .25s}.dl-card:hover{transform:translateY(-3px);border-color:var(--doc-accent);background:var(--doc-soft)}.dl-card__top{display:flex;align-items:center;gap:9px;margin-bottom:28px;color:var(--doc-muted);font-size:9px}.dl-card__top span:first-child{color:var(--doc-accent);font-family:ui-monospace,monospace}.dl-card__top span:nth-child(2){padding:3px 5px;border:1px solid var(--doc-line);border-radius:2px;color:var(--doc-accent-2)}.dl-card__top span:last-child{margin-left:auto;overflow:hidden;text-overflow:ellipsis;white-space:nowrap}.dl-card h2{margin:0;font-size:19px;font-weight:650;line-height:1.45;letter-spacing:-.025em}.dl-card p{display:-webkit-box;margin:10px 0 18px;overflow:hidden;-webkit-box-orient:vertical;-webkit-line-clamp:3;color:var(--doc-muted);font-size:12px;line-height:1.75}.dl-card__foot{display:flex;justify-content:space-between;gap:12px;margin-top:auto;padding-top:12px;border-top:1px solid var(--doc-line);color:var(--doc-muted);font-size:9px}.dl-card__foot span:last-child{color:var(--doc-accent)}.dl-empty{padding:32px;border:1px dashed var(--doc-line-strong);color:var(--doc-muted);font-size:13px}.dd-hero{position:relative;overflow:visible;padding:calc(var(--header-height) + 34px) 0 clamp(34px,5vw,52px);border-bottom:1px solid var(--doc-line)}.dd-hero__grid{position:absolute;inset:0;background-image:linear-gradient(var(--doc-line) 1px,transparent 1px),linear-gradient(90deg,var(--doc-line) 1px,transparent 1px);background-size:72px 72px;opacity:.38;-webkit-mask-image:linear-gradient(180deg,black,transparent 82%);mask-image:linear-gradient(180deg,black,transparent 82%);pointer-events:none}.dd-crumbs{position:relative;z-index:2;display:flex;flex-wrap:wrap;gap:8px;color:var(--doc-muted);font-size:12px}.dd-crumbs a{color:var(--doc-muted);text-decoration:none}.dd-crumbs a:hover{color:var(--doc-accent)}.dd-back{display:inline-flex;align-items:center;gap:7px;margin-top:28px;color:var(--doc-accent);font-size:11px;text-decoration:none}.dd-back,.dd-hero__main{position:relative;z-index:2}.dd-hero__main{display:flex;align-items:flex-end;justify-content:space-between;gap:40px;padding-top:28px}.dd-tag{display:inline-flex;padding:4px 7px;border:1px solid color-mix(in srgb,var(--doc-accent) 30%,transparent);border-radius:3px;color:var(--doc-accent-2);font-size:9px;letter-spacing:.08em}.dd-hero h1{max-width:900px;margin:17px 0 0;font-family:var(--font-family-chinese);font-size:clamp(32px,4.3vw,56px);font-weight:800;line-height:1.18;letter-spacing:-.045em}.dd-summary{max-width:780px;margin:16px 0 0;color:var(--doc-muted);font-size:14px;line-height:1.85}.dd-tools{position:relative;display:flex;flex:0 0 auto;flex-wrap:wrap;gap:9px;padding-bottom:4px}.dd-tools button{display:inline-flex;min-height:44px;align-items:center;gap:8px;padding:0 17px;border:1px solid var(--doc-line-strong);border-radius:5px;background:transparent;color:var(--current-text-primary);font:inherit;font-size:12px;font-weight:650;cursor:pointer;transition:background .2s ease,border-color .2s ease,color .2s ease,transform .2s ease}.dd-tools button:hover{transform:translateY(-1px)}.dd-tools button:focus-visible{outline:2px solid var(--doc-accent);outline-offset:2px}.dd-tools button svg{width:15px;height:15px}.dd-tools .dd-export{border-color:var(--doc-accent);background:var(--doc-accent);color:#fff;box-shadow:0 6px 20px color-mix(in srgb,var(--doc-accent) 24%,transparent)}.dd-tools .dd-export:hover{background:color-mix(in srgb,var(--doc-accent) 84%,#fff)}.dd-tools .dd-export:disabled{opacity:.65;cursor:wait}.dd-tools .dd-share{border-color:color-mix(in srgb,var(--doc-accent) 48%,var(--doc-line-strong));color:var(--doc-accent);background:var(--doc-soft)}.dd-tools .dd-share:hover{border-color:var(--doc-accent)}.dd-share-wrap{position:relative}.dd-share-wrap:after{content:"";position:absolute;left:0;right:0;bottom:100%;height:12px}.dd-share-menu{position:absolute;z-index:60;right:0;bottom:calc(100% + 10px);display:flex;flex-direction:column-reverse;align-items:flex-end;gap:8px;width:auto;padding:0;border:0;background:transparent;box-shadow:none;opacity:0;visibility:hidden;pointer-events:none;transition:opacity .16s ease,visibility .16s ease}.dd-share-wrap:focus-within .dd-share-menu,.dd-share-wrap:hover .dd-share-menu,.dd-share-wrap[data-open=true] .dd-share-menu{opacity:1;visibility:visible;pointer-events:auto}.dd-tools .dd-share-menu .dd-share-item{display:inline-flex;min-height:40px;align-items:center;gap:9px;padding:0 14px 0 6px;border:1px solid var(--doc-line-strong);border-radius:999px;background:var(--current-surface);color:var(--current-text-primary);box-shadow:0 10px 28px rgba(0,0,0,.24);font:inherit;font-size:11px;font-weight:650;white-space:nowrap;cursor:pointer;opacity:0;transform:translateY(12px) scale(.72);transform-origin:bottom right;transition:opacity .16s ease,transform .26s cubic-bezier(.22,1,.36,1),border-color .18s ease,color .18s ease;transition-delay:0s}.dd-share-wrap:focus-within .dd-share-item,.dd-share-wrap:hover .dd-share-item,.dd-share-wrap[data-open=true] .dd-share-item{opacity:1;transform:translateY(0) scale(1);transition-delay:calc(var(--i) * 45ms)}.dd-tools .dd-share-menu .dd-share-item:hover{border-color:var(--doc-accent);color:var(--doc-accent);transform:translateY(0) scale(1.02)}.dd-share-icon{display:grid;width:30px;height:30px;flex:0 0 auto;place-items:center;border-radius:50%;color:#fff}.dd-tools .dd-share-icon svg{width:19px;height:19px}.dd-share-icon--link{background:var(--doc-soft);color:var(--doc-accent)}.dd-share-icon--wechat{background:#07c160}.dd-share-icon--weibo{background:#e6162d}.dd-share-icon--qq{background:#12b7f5}.dd-share-symbol{font-family:var(--font-family-chinese);font-size:15px;font-weight:800;line-height:1}.dd-pdf-toast{position:fixed;z-index:120;right:24px;bottom:calc(env(safe-area-inset-bottom) + 92px);display:flex;width:min(460px,calc(100vw - 32px));align-items:center;gap:10px;padding:12px 13px;border:1px solid var(--doc-line-strong);border-top:2px solid var(--doc-accent);border-radius:7px;background:var(--current-surface);box-shadow:0 18px 50px rgba(0,0,0,.3);color:var(--current-text-primary);animation:dd-toast-in .22s cubic-bezier(.22,1,.36,1)}.dd-pdf-toast p{flex:1;margin:0;color:var(--current-text-secondary);font-size:11px;line-height:1.6}.dd-pdf-toast a{flex:0 0 auto;color:var(--doc-accent);font-size:11px;font-weight:650;text-decoration:none;white-space:nowrap}.dd-pdf-toast>button{flex:0 0 auto;width:22px;height:22px;padding:0;border:0;background:transparent;color:var(--doc-muted);font-size:18px;line-height:1;cursor:pointer}.dd-pdf-toast>button:hover{color:var(--current-text-primary)}@keyframes dd-toast-in{0%{opacity:0;transform:translateY(8px)}to{opacity:1;transform:translateY(0)}}.dd-pdf-holder{position:fixed;z-index:-1;left:-10000px;top:0;width:700px}.dd-pdf-export{width:700px!important;max-width:700px;padding:24px;box-sizing:border-box;background:#fff!important;color:#111827!important;font-family:var(--font-family-chinese)}.dd-pdf-export *{background:transparent!important;box-shadow:none!important;color:#111827!important;border-color:#d1d5db!important}.dd-pdf-export h2{margin:26px 0 12px;padding-top:10px;border-top:1px solid #d1d5db;font-size:22px;line-height:1.35}.dd-pdf-export h2:first-child{margin-top:0;padding-top:0;border-top:0}.dd-pdf-export li,.dd-pdf-export p{max-width:100%;overflow-wrap:anywhere}.dd-pdf-export p{margin:0 0 10px;font-size:12.5px;line-height:1.75}.dd-pdf-export ul{margin:10px 0 16px;padding:0;list-style:none}.dd-pdf-export li{position:relative;padding:5px 0 5px 15px;font-size:12px;line-height:1.7}.dd-pdf-export li:before{content:"";position:absolute;left:0;top:12px;width:4px;height:4px;border-radius:50%;background:#4a9bff}.dd-pdf-export .dd-code{font-size:10px}.dd-pdf-export .dd-code,.dd-pdf-export .dd-note{border:1px solid #d1d5db!important;border-left:2px solid #4a9bff!important}.dd-body{padding:clamp(48px,7vw,82px) 0}.dd-grid{display:grid;grid-template-columns:210px minmax(0,1fr) 250px;gap:40px;align-items:start}.dd-toc{position:sticky;top:calc(var(--header-height) + 20px);display:flex;flex-direction:column;gap:3px}.dd-toc>span{margin-bottom:10px;color:var(--doc-muted);font-family:ui-monospace,monospace;font-size:9px;letter-spacing:.13em}.dd-toc a{padding:6px 0;border-bottom:1px solid var(--doc-line);color:var(--doc-muted);font-size:11px;line-height:1.5;text-decoration:none}.dd-toc a:hover{color:var(--doc-accent)}.dd-article{min-width:0;max-width:780px}.dd-article h2{margin:0 0 14px;padding-top:7px;font-family:var(--font-family-chinese);font-size:clamp(23px,2.6vw,30px);font-weight:750;letter-spacing:-.025em;scroll-margin-top:calc(var(--header-height) + 18px)}.dd-article h2:not(:first-child){margin-top:46px;padding-top:24px;border-top:1px solid var(--doc-line-strong)}.dd-article p{margin:0 0 13px;color:var(--doc-muted);font-size:14px;line-height:1.95}.dd-article ul{margin:14px 0 20px;padding:0;list-style:none}.dd-article li{position:relative;padding:7px 0 7px 17px;color:var(--doc-muted);font-size:13px;line-height:1.8}.dd-article li:before{content:"";position:absolute;left:0;top:15px;width:5px;height:5px;border-radius:50%;background:var(--doc-accent)}.dd-article code{padding:2px 5px;border:1px solid var(--doc-line);border-radius:3px;background:color-mix(in srgb,var(--current-surface) 60%,transparent);color:var(--doc-accent-2);font-size:.9em}.dd-code{margin:18px 0 22px;overflow-x:auto;padding:16px 18px;border:1px solid var(--doc-line);border-left:2px solid var(--doc-accent);border-radius:0 5px 5px 0;background:color-mix(in srgb,var(--current-surface) 70%,transparent);color:var(--current-text-secondary);font-family:ui-monospace,SFMono-Regular,Menlo,monospace;font-size:11px;line-height:1.8;white-space:pre}.dd-note{margin:24px 0;padding:16px 18px;border:1px solid var(--doc-line);border-left:2px solid var(--doc-accent);background:var(--doc-soft);color:var(--doc-muted);font-size:12px;line-height:1.75}.dd-note strong{color:var(--doc-accent-2)}.dd-aside{position:sticky;top:calc(var(--header-height) + 20px);display:flex;flex-direction:column;gap:12px}.dd-card{padding:16px;border:1px solid var(--doc-line);border-radius:5px;background:color-mix(in srgb,var(--current-surface) 42%,transparent)}.dd-card>span{display:block;margin-bottom:12px;color:var(--doc-muted);font-family:ui-monospace,monospace;font-size:9px;letter-spacing:.12em}.dd-card dl{display:grid;grid-template-columns:52px 1fr;gap:8px;margin:0;font-size:10px;line-height:1.6}.dd-card dt{color:var(--doc-muted)}.dd-card dd{margin:0;color:var(--current-text-secondary)}.dd-rel{display:flex;flex-direction:column;gap:8px}.dd-rel a{display:block;padding-top:9px;border-top:1px solid var(--doc-line);color:var(--current-text-secondary);font-size:11px;line-height:1.6;text-decoration:none}.dd-rel a:hover{color:var(--doc-accent)}.dd-rel a span{display:block;margin-bottom:2px;color:var(--doc-accent-2);font-size:8px}.dd-cta{display:flex;align-items:center;justify-content:space-between;gap:20px;margin-top:36px;padding:22px;border:1px solid var(--doc-line);border-top:2px solid var(--doc-accent);border-radius:0 0 5px 5px}.dd-cta strong{font-size:15px}.dd-cta p{margin:6px 0 0;color:var(--doc-muted);font-size:11px}.dd-cta a,.dd-cta button{flex:0 0 auto;padding:9px 12px;border:0;border-radius:4px;background:var(--doc-accent);color:#fff;font:inherit;font-size:10px;font-weight:650;text-decoration:none;cursor:pointer}.dd-related{padding:clamp(42px,5vw,64px) 0;border-top:1px solid var(--doc-line);background:color-mix(in srgb,var(--current-surface) 36%,transparent)}.dd-related h2{margin:0 0 18px;font-size:24px;font-weight:700;letter-spacing:-.03em}.dd-related__grid{display:grid;grid-template-columns:repeat(3,1fr);gap:10px}.dd-related__grid a{padding:17px;border:1px solid var(--doc-line);border-radius:5px;color:inherit;text-decoration:none}.dd-related__grid a:hover{border-color:var(--doc-accent)}.dd-related__grid span{color:var(--doc-accent-2);font-size:8px}.dd-related__grid h3{margin:9px 0 0;font-size:14px;font-weight:650;line-height:1.5}@media (max-width:1080px){.dl-grid{grid-template-columns:repeat(2,minmax(0,1fr))}.dd-grid{grid-template-columns:180px minmax(0,1fr);gap:28px}.dd-aside{display:none}}@media (max-width:760px){.dd-container,.dl-container{width:min(100% - 32px,1280px)}.dl-tools__inner{align-items:stretch;flex-direction:column;gap:12px}.dl-search{width:100%}.dl-cats{overflow-x:auto;flex-wrap:nowrap;padding-bottom:2px}.dl-cats button{flex:0 0 auto}.dl-scroll{max-height:none;overflow:visible;padding-right:0}.dl-grid{grid-template-columns:1fr}.dl-card{min-height:0}.dd-hero{padding-top:calc(var(--header-height) + 26px)}.dd-hero__main{align-items:flex-start;flex-direction:column;gap:18px}.dd-tools{width:100%}.dd-share-wrap,.dd-tools>button{flex:1 1 auto}.dd-tools .dd-share{width:100%;justify-content:center}.dd-share-menu{right:0;left:auto}.dd-hero h1{font-size:clamp(30px,8.4vw,44px)}.dd-grid{grid-template-columns:1fr;gap:26px}.dd-toc{position:static;flex-direction:row;flex-wrap:wrap;gap:6px 16px}.dd-toc>span{width:100%}.dd-toc a{border-bottom:0}.dd-cta{align-items:flex-start;flex-direction:column}.dd-pdf-toast{right:16px;left:16px;bottom:calc(env(safe-area-inset-bottom) + 82px);width:auto}.dd-related__grid{grid-template-columns:1fr}}@media (prefers-reduced-motion:reduce){.dd-page *,.dl-page *{transition:none!important;animation:none!important}}