:root{--bg:#f8f8f4;--paper:#fff;--text:#24372e;--body:#3d4943;--muted:#7a847e;--line:#e3e6de;--accent:#285842;--soft:#eaf0e5;--lime:#dce9ab;--code:#f0f2eb;--reader-size:18px;--header-height:72px;color-scheme:light}
html[data-theme=dark]{--bg:#161d19;--paper:#1c2520;--text:#e2e8e1;--body:#c5cfc7;--muted:#94a396;--line:#344137;--accent:#b7dba5;--soft:#26382b;--lime:#c2dc91;--code:#202d24;color-scheme:dark}
*{box-sizing:border-box}html{scroll-behavior:smooth;scroll-padding-top:104px}body{margin:0;background:var(--bg);color:var(--text);font-family:-apple-system,BlinkMacSystemFont,"PingFang SC","Microsoft YaHei",sans-serif;-webkit-font-smoothing:antialiased}button,input,a{-webkit-tap-highlight-color:transparent}button,input{font:inherit}button,a{touch-action:manipulation}button{cursor:pointer}button{color:inherit}a{color:inherit;text-decoration:none}button:focus-visible,a:focus-visible,input:focus-visible{outline:3px solid var(--accent);outline-offset:4px}button:disabled{cursor:default;opacity:.35}button{border:0;background:none}button[hidden],[hidden]{display:none!important}::selection{background:var(--lime);color:#173e30}.sr-only{position:absolute;width:1px;height:1px;overflow:hidden;clip:rect(0,0,0,0);white-space:nowrap}.skip-link{position:fixed;top:-80px;left:20px;padding:12px 20px;background:var(--accent);color:var(--bg);z-index:100}.skip-link:focus{top:12px}
.site-header{height:var(--header-height);position:sticky;top:0;z-index:20;border-bottom:1px solid var(--line);background:var(--bg)}.header-inner{max-width:1416px;height:100%;margin:auto;padding:0 38px;display:flex;align-items:center;justify-content:space-between;gap:20px}.brand{display:flex;align-items:center;gap:12px;font-size:20px;font-weight:650;letter-spacing:-.7px}.brand-mark{display:grid;place-items:center;position:relative;width:34px;height:34px;background:#173e30;color:#e6eeb7;font:700 23px/1 ui-monospace,monospace;border-radius:8px}.brand-mark span{position:absolute;right:5px;bottom:5px;font-size:16px}.brand-subtitle{margin-left:13px;padding-left:13px;border-left:1px solid var(--line);font-size:13px;font-weight:450;letter-spacing:1px;color:var(--muted)}.header-actions{display:flex;align-items:center;gap:20px;font-size:13px}.toolbar-button{display:flex;align-items:center;gap:7px;padding:9px 3px;min-height:44px;white-space:nowrap}.toolbar-button:hover{color:var(--accent)}.search-trigger>span:first-child{font-size:28px;line-height:1}.toolbar-button kbd{font:10px/1.4 ui-monospace,monospace;border:1px solid var(--line);padding:3px 5px;border-radius:4px;color:var(--muted)}.aa{font-family:Georgia,serif;font-size:20px}.mobile-only{display:none}
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.article-body{padding-top:33px}.content{font-size:var(--reader-size);line-height:1.95;letter-spacing:.25px;color:var(--body);overflow-wrap:anywhere;word-break:normal}.content p{margin:0 0 1.2em}.content strong{color:var(--text);font-weight:650}.content h3{font-size:1.15em;line-height:1.6;color:var(--text);margin:2em 0 1em}.content a{color:var(--accent);text-decoration:underline;text-underline-offset:4px;word-break:break-all}.content :not(pre)>code{font: .86em/1.65 ui-monospace,SFMono-Regular,Menlo,Consolas,monospace;background:var(--code);padding:3px 5px;border-radius:4px;color:var(--accent);overflow-wrap:anywhere;white-space:break-spaces}.chapter{padding-top:55px;margin-top:42px;border-top:1px solid var(--line);scroll-margin-top:104px}.chapter-heading{display:flex;align-items:flex-start;gap:15px;margin-bottom:29px}.chapter-number{font:12px/2 ui-monospace,monospace;color:var(--accent);padding-top:3px}.chapter-heading h2{font-size:27px;line-height:1.45;font-weight:600;letter-spacing:-.4px;margin:0;flex:1}.copy-chapter{font-size:10px;white-space:nowrap;color:var(--muted);padding:8px 0 8px 10px;min-height:40px;opacity:.7}.copy-chapter:hover{opacity:1;color:var(--accent)}.tutorial-image{margin:32px 0 35px}.image-button{display:block;max-width:100%;padding:0;margin:0 auto;cursor:zoom-in;border-radius:9px;overflow:hidden;outline-offset:5px;line-height:0;box-shadow:0 0 0 1px var(--line)}.tutorial-image img{display:block;height:auto;width:auto;max-width:100%;background:var(--paper)}.introduction .tutorial-image:first-child{margin-top:0;margin-bottom:33px}.example{margin:28px 0;background:var(--code);border:1px solid var(--line);border-radius:8px;overflow:hidden;letter-spacing:0}.example-toolbar{display:flex;align-items:center;justify-content:space-between;gap:12px;padding:10px 17px;border-bottom:1px solid var(--line);font-size:10px;line-height:1.5;color:var(--muted)}.copy-code{border:1px solid var(--line);border-radius:4px;padding:6px 12px;font-size:11px;background:var(--bg);min-height:32px}.copy-code:hover{border-color:var(--accent);color:var(--accent)}.example pre{margin:0;padding:20px 22px;white-space:pre-wrap;overflow-wrap:anywhere;font: .82em/1.95 ui-monospace,SFMono-Regular,Menlo,Consolas,monospace;color:var(--body);tab-size:2}.example pre code{font:inherit}.search-focus{outline:3px solid var(--accent);outline-offset:10px;border-radius:2px}

dialog{border:1px solid var(--line);border-radius:13px;background:var(--paper);color:var(--text);padding:24px;max-height:calc(100dvh - 40px);box-shadow:0 24px 100px #0003}dialog::backdrop{background:#101d1877;backdrop-filter:blur(3px)}body:has(dialog[open]){overflow:hidden}.dialog-title{display:flex;align-items:center;justify-content:space-between;gap:16px;margin:0 0 20px}.dialog-title h2{font-size:18px;font-weight:600;margin:0}.dialog-title small{font-size:12px;font-weight:400;color:var(--muted);margin-left:8px}.dialog-title button{font-size:26px;min-width:36px;min-height:36px;line-height:1}.settings-dialog{width:min(380px,calc(100vw - 32px))}.setting-row{display:flex;justify-content:space-between;align-items:center;gap:15px;font-size:13px;padding:17px 0;border-top:1px solid var(--line)}.size-controls,.theme-controls{display:flex;align-items:center;gap:5px}.size-controls button{width:40px;min-height:40px;background:var(--soft);border-radius:5px}.size-controls output{min-width:25px;text-align:center;font:12px ui-monospace,monospace}.theme-controls button{min-height:40px;min-width:59px;padding:8px 13px;border:1px solid var(--line);border-radius:5px}.theme-controls button[aria-pressed=true]{background:var(--accent);border-color:var(--accent);color:var(--bg)}.setting-hint{font-size:11px;color:var(--muted);margin:10px 0 0}.search-dialog{width:min(660px,calc(100vw - 28px));padding:25px}.search-box{display:block}.search-box input{width:100%;border:1px solid var(--line);background:var(--bg);color:var(--text);padding:14px;border-radius:7px;font-size:16px;outline-offset:2px}.search-status{color:var(--muted);font-size:12px;margin:18px 0 12px}.search-results{max-height:55dvh;overflow-y:auto;overscroll-behavior:contain}.search-result{width:100%;display:block;text-align:left;padding:15px 4px;border-top:1px solid var(--line)}.search-result:hover{background:var(--soft)}.search-result strong{display:block;font-size:12px;font-weight:600;color:var(--accent);margin-bottom:6px}.search-result span{display:block;font-size:13px;line-height:1.8;color:var(--body)}.toc-dialog{width:min(390px,calc(100vw - 28px));height:calc(100dvh - 50px);padding:22px;overflow:hidden}.toc-dialog .toc{height:calc(100% - 118px);padding-right:0}.toc-dialog .toc-link{font-size:14px;padding-top:11px;padding-bottom:11px}.toc-dialog .toc-group-title{font-size:11px}.drawer-download{display:block;border-top:1px solid var(--line);font-size:12px;color:var(--accent);padding-top:16px;margin-top:13px}.image-dialog{width:calc(100vw - 28px);max-width:1500px;height:calc(100dvh - 28px);max-height:none;border:0;background:var(--bg);padding:0;overflow:hidden}.lightbox-toolbar{height:64px;display:flex;align-items:center;justify-content:space-between;padding:0 24px;border-bottom:1px solid var(--line);font-size:12px;gap:12px}.lightbox-toolbar p{margin:0}.lightbox-toolbar>div{display:flex;gap:10px}.lightbox-toolbar button{min-height:40px;padding:7px 10px;background:var(--soft);border-radius:5px;white-space:nowrap}.image-viewport{height:calc(100% - 64px);overflow:auto;overscroll-behavior:contain;display:grid;place-items:center;padding:20px;touch-action:pan-x pan-y pinch-zoom}.image-viewport img{display:block;max-width:100%;max-height:calc(100dvh - 135px);width:auto;height:auto;object-fit:contain}.image-dialog.is-zoomed .image-viewport{display:block;text-align:center}.image-dialog.is-zoomed img{max-width:none;max-height:none;display:inline-block;vertical-align:top;min-width:100%}.toast{position:fixed;bottom:40px;left:50%;transform:translateX(-50%) translateY(15px);background:var(--text);color:var(--bg);font-size:13px;padding:12px 20px;border-radius:7px;z-index:100;opacity:0;pointer-events:none;transition:opacity .2s,transform .2s;max-width:calc(100vw - 40px);width:max-content}.toast.visible{opacity:1;transform:translateX(-50%) translateY(0)}.mobile-reading-bar{display:none}.reading-progress{height:3px;position:fixed;top:0;left:0;right:0;background:var(--accent);z-index:30;transform-origin:left;transform:scaleX(0);animation:reading linear;animation-timeline:scroll(root block)}@keyframes reading{to{transform:scaleX(1)}}
@media(min-width:1440px){.page-layout{gap:100px}.article-header{padding-top:72px}.article-header h1{font-size:72px}.title-code{font-size:88px}}
@media(max-width:1100px){.page-layout{grid-template-columns:216px minmax(0,1fr);gap:42px;padding:0 30px}.header-inner{padding:0 30px}.toc-link{font-size:11px}.chapter-heading h2{font-size:24px}.article-header h1{font-size:58px}.title-code{font-size:72px}}
@media(max-width:800px){:root{--header-height:62px}.header-inner{padding:0 22px}.header-actions{gap:16px}.brand-subtitle{display:none}.page-layout{display:block;padding:0 26px;max-width:740px}.sidebar{display:none}.mobile-only{display:flex}.desktop-only{display:none}.toolbar-button kbd{display:none}.search-trigger>span:nth-child(2){display:none}main{padding-bottom:85px}.article-header{padding-top:43px;padding-bottom:34px}.eyebrow{font-size:11px;letter-spacing:1.5px;margin-bottom:23px}.article-header h1{font-size:46px;letter-spacing:-1.5px;line-height:1.25;margin-bottom:22px}.title-code{font-size:72px}.hero-description{font-size:14px;line-height:1.85;margin-bottom:23px}.hero-bottom{margin-top:27px}.content{line-height:1.95}.article-body{padding-top:27px}.chapter{padding-top:35px;margin-top:35px}.chapter-heading{gap:10px;margin-bottom:25px;flex-wrap:wrap}.chapter-heading h2{font-size:24px}.chapter-number{font-size:11px;padding-top:2px}.copy-chapter{font-size:10px}.mobile-reading-bar{position:fixed;left:0;right:0;bottom:0;z-index:15;display:flex;align-items:center;justify-content:space-between;gap:18px;padding:7px 20px calc(7px + env(safe-area-inset-bottom));border-top:1px solid var(--line);background:var(--bg);min-height:53px;font-size:12px}.mobile-reading-bar button{font-size:12px;min-height:37px;white-space:nowrap;padding:0}.mobile-reading-bar button span{margin-right:4px}.mobile-reading-bar>span{min-width:0;flex:1;white-space:nowrap;text-overflow:ellipsis;overflow:hidden;font-size:11px;color:var(--muted)}.mobile-reading-bar a{width:32px;min-height:37px;display:grid;place-items:center;font-size:21px}.toast{bottom:80px}.tutorial-image{margin:26px 0 29px}.example pre{padding:17px}.lightbox-toolbar{padding:0 12px;font-size:11px}.lightbox-toolbar button{padding:7px 9px}.image-viewport{padding:12px}}
@media(max-width:380px){.header-inner{padding:0 16px}.header-actions{gap:12px}.page-layout{padding:0 20px}.brand{font-size:18px;gap:9px}.brand-mark{width:30px;height:30px;font-size:21px}.article-header h1{font-size:39px}.title-code{font-size:65px}.article-meta{font-size:10px;gap:7px}.meta-divider{margin:0 1px}.hero-bottom{gap:17px}.hero-bottom p{font-size:10px}.start-button{padding:13px 17px;gap:23px}.chapter-heading h2{font-size:22px}.copy-chapter{flex-basis:100%;text-align:right;padding:0;min-height:24px;margin-top:-7px}.chapter-heading{row-gap:5px}}
@media(prefers-reduced-motion:reduce){html{scroll-behavior:auto}*,*::before,*::after{animation:none!important;transition:none!important}}
@media print{.site-header,.sidebar,.mobile-reading-bar,.reading-progress,.copy-chapter,.example-toolbar,.hero-bottom,dialog{display:none!important}.page-layout{display:block;padding:0;max-width:none}body{background:white;color:black}main{max-width:none}.article-header{padding-top:0}.content{font-size:12pt}.chapter{break-before:page}.tutorial-image{break-inside:avoid}.image-button{box-shadow:none}.tutorial-image img{max-height:75vh;max-width:100%;object-fit:contain}.example{break-inside:avoid}.example pre{color:black}}