@font-face{font-family:Smiley;src:url('../aperture/SmileySans-Oblique.woff2') format('woff2');font-weight:400;font-style:normal;font-display:swap}
:root{--paper:#f4f7ee;--ink:#263c28;--muted:#617158;--green:#597d36;--line:#ced6c3;--wash:#eaf0df;--sans:-apple-system,BlinkMacSystemFont,'Helvetica Neue','PingFang SC','Microsoft YaHei',sans-serif;--serif:Georgia,'Times New Roman','Songti SC','Noto Serif CJK SC',serif}
*{box-sizing:border-box}html{scroll-behavior:smooth;scroll-padding-top:40px}body{margin:0;background:var(--paper);color:var(--ink);font:16px/1.7 var(--sans);-webkit-font-smoothing:antialiased}a{color:inherit;text-decoration:none}a:hover{color:var(--green)}a:focus-visible,summary:focus-visible,.math-block:focus-visible{outline:2px solid var(--green);outline-offset:5px}::selection{background:#cdddb7}.skip{position:fixed;top:-100px;left:20px;z-index:20;padding:10px 18px;background:var(--ink);color:var(--paper)}.skip:focus{top:12px}.blog-header{height:110px;padding:0 4.8%;display:flex;align-items:center;justify-content:space-between;gap:30px}.identity{display:flex;align-items:center;gap:13px;font:23px var(--serif);letter-spacing:3px}.crest{display:block;width:37px;height:37px;background:var(--ink);mask:url('../aperture/crest-small.png') center/contain no-repeat;-webkit-mask:url('../aperture/crest-small.png') center/contain no-repeat}.blog-header nav{display:flex;gap:36px;font-size:14px}.blog-header nav a{display:flex;align-items:center;min-height:44px}.blog-header [aria-current]{text-decoration:underline;text-underline-offset:8px;text-decoration-color:var(--line)}.eyebrow{margin:0;font-size:11px;letter-spacing:1.7px;line-height:1.7;color:var(--muted)}.reading-progress{position:fixed;top:0;left:0;right:0;height:2px;z-index:15;pointer-events:none}.reading-progress span{display:block;height:100%;background:var(--green);transform:scaleX(0);transform-origin:left}
.post-header{max-width:1100px;margin:0 auto;padding:42px 0 65px;border-bottom:1px solid var(--line)}.back-link{display:inline-flex;align-items:center;gap:16px;font-size:12px;color:var(--muted);min-height:44px;margin-bottom:45px}.post-header>.eyebrow{margin-bottom:23px}.post-header h1{margin:0;display:flex;align-items:baseline;flex-wrap:wrap;gap:20px 30px;font-weight:400}.title-latin{font:400 clamp(80px,8vw,112px)/1.08 Smiley,'Arial Narrow',sans-serif;letter-spacing:-3px}.title-chinese{font:400 39px/1.5 var(--serif);letter-spacing:3px}.post-meta{display:flex;align-items:center;flex-wrap:wrap;gap:8px 24px;font-size:12px;color:var(--muted);margin-top:30px}.source-link{display:inline-flex;gap:24px;align-items:center;font-size:12px;min-height:40px;border-bottom:1px solid var(--line);margin-top:13px}.source-link span{font-size:18px}.reading-layout{max-width:1100px;margin:0 auto;display:grid;grid-template-columns:minmax(0,780px) 220px;gap:100px;padding-top:58px}.post-body{min-width:0;font-size:17px;line-height:2;overflow-wrap:break-word}.post-body>p{margin:0 0 24px}.post-body>p:first-child{font-size:19px;line-height:1.95;margin-bottom:48px}.post-body h2{font:400 31px/1.5 var(--serif);letter-spacing:.2px;margin:70px 0 27px;padding-top:28px;border-top:1px solid var(--line);scroll-margin-top:45px}.post-body h2:first-of-type{margin-top:0}.post-body h3{font:400 25px/1.65 var(--serif);margin:48px 0 22px;scroll-margin-top:45px}.post-body h4{font-size:20px;line-height:1.6;font-weight:500;margin:38px 0 19px}.post-body h5{font-size:18px;line-height:1.7;font-weight:500;margin:32px 0 18px}.post-body h6{font-size:16px;line-height:1.7;font-weight:500;margin:26px 0 17px;color:var(--muted)}.post-body a{color:var(--green);text-decoration:underline;text-underline-offset:5px;text-decoration-color:#a9bb97;word-break:break-word}.post-body strong{font-weight:600}.post-body em{font-family:var(--serif)}.post-body .katex{font-size:1.07em}.math-block{margin:30px 0 33px;padding:22px 16px;overflow-x:auto;background:var(--wash);border-left:2px solid #a5b790;border-radius:0;max-width:100%;overscroll-behavior-inline:contain}.math-block .katex-display{margin:0;width:max-content;min-width:100%;text-align:center}.post-figure{margin:36px 0 39px}.post-figure>a{display:block;line-height:0;border:1px solid var(--line);background:#fafaf4;overflow:hidden}.post-figure img{display:block;width:100%;height:auto;max-width:100%;transition:opacity .2s}.post-figure a:hover img{opacity:.9}.post-figure figcaption{display:flex;justify-content:space-between;gap:20px;color:var(--muted);font-size:11px;line-height:1.8;padding-top:10px}.post-body>p:last-child{font-size:13px;color:var(--muted);padding-top:25px;border-top:1px solid var(--line);margin-top:60px}.toc{min-width:0}.toc-inner{position:sticky;top:45px}.toc nav{margin-top:23px;display:flex;flex-direction:column;gap:7px}.toc nav a{font-size:12px;color:var(--muted);line-height:1.7;display:block;padding:5px 0 5px 15px;border-left:1px solid var(--line);transition:color .15s,border-color .15s}.toc nav a:hover,.toc nav a.active{color:var(--ink);border-left-color:var(--green)}.toc nav a.toc-sub{font-size:11px;padding-left:26px;color:#7a8772}.toc nav a.toc-sub.active{color:var(--ink)}.back-top{display:inline-block;font-size:11px;color:var(--muted);margin-top:30px;min-height:40px}.mobile-toc{display:none}.post-footer{max-width:1100px;margin:80px auto 0;padding:30px 0 40px;border-top:1px solid var(--line);display:flex;justify-content:space-between;gap:20px;font-size:12px;color:var(--muted)}.post-footer a{display:flex;gap:25px}
@media(max-width:1250px){.post-header,.reading-layout,.post-footer{margin-left:7%;margin-right:7%}.reading-layout{grid-template-columns:minmax(0,1fr) 190px;gap:65px}}
@media(max-width:950px){.reading-layout{display:block;max-width:760px;margin-left:auto;margin-right:auto;padding:40px 6% 0}.post-header{padding-bottom:45px}.toc{display:none}.mobile-toc{display:block;margin:0 0 35px;border-top:1px solid var(--line);border-bottom:1px solid var(--line);font-size:13px}.mobile-toc summary{display:flex;justify-content:space-between;align-items:center;min-height:52px;cursor:pointer;list-style:none}.mobile-toc summary::-webkit-details-marker{display:none}.mobile-toc[open] summary span{transform:rotate(45deg)}.mobile-toc nav{display:flex;flex-direction:column;gap:14px;padding:10px 0 23px}.mobile-toc nav a{color:var(--muted)}.mobile-toc .toc-sub{padding-left:18px;font-size:12px}.post-body h2{font-size:29px}.post-body h3{font-size:24px}}
@media(max-width:600px){html{scroll-padding-top:24px}.blog-header{height:90px;padding:0 6%;gap:18px}.identity{font-size:20px;gap:9px}.crest{width:30px;height:30px}.blog-header nav{gap:18px;font-size:12px}.post-header{margin:0 6%;padding:13px 0 35px}.back-link{margin-bottom:29px}.post-header>.eyebrow{font-size:10px;margin-bottom:16px}.post-header h1{gap:0 18px;align-items:baseline}.title-latin{font-size:72px;letter-spacing:-2px}.title-chinese{font-size:27px;letter-spacing:2px}.post-meta{gap:5px 17px;font-size:11px;margin-top:21px}.source-link{font-size:11px;margin-top:12px}.reading-layout{padding-top:29px}.post-body{font-size:16px;line-height:1.95}.post-body>p{margin-bottom:21px}.post-body>p:first-child{font-size:17px;margin-bottom:35px}.post-body h2{font-size:26px;margin-top:52px;padding-top:23px}.post-body h3{font-size:22px;margin-top:36px}.post-body h4{font-size:19px}.post-body h5{font-size:17px}.math-block{margin:25px 0;padding:19px 13px}.math-block .katex{font-size:1em}.post-figure{margin:27px 0}.post-figure figcaption{font-size:10px}.post-footer{margin:55px 6% 0;padding:24px 0 30px;font-size:10px}}
@media(max-width:360px){.blog-header nav{gap:12px}.identity{font-size:19px;gap:7px}.title-latin{font-size:64px}.title-chinese{font-size:24px}.post-header h1{gap:0 12px}}
@media(prefers-reduced-motion:reduce){html{scroll-behavior:auto}*,*:before,*:after{transition:none!important;animation:none!important}}

/* Paired illustrations retain the author's visual correspondence. */
.figure-pair{display:grid;grid-template-columns:minmax(0,1fr) minmax(0,1fr);gap:16px;margin:36px 0 39px}.figure-pair .post-figure{margin:0;min-width:0}.figure-pair .post-figure a{height:auto}.figure-pair figcaption{font-size:10px}.post-figure.figure-small{max-width:470px;margin:34px auto 39px}

.figure-steps{margin:36px 0 40px;border:1px solid var(--line);background:#f8faf3}.step-tabs{display:grid;grid-template-columns:1fr 1fr;border-bottom:1px solid var(--line)}.step-tabs button,.step-next{font:inherit;cursor:pointer;color:inherit;background:transparent;border:0}.step-tabs button{padding:15px 19px;text-align:left;font-size:13px;line-height:1.7;color:var(--muted);position:relative}.step-tabs button+button{border-left:1px solid var(--line)}.step-tabs button span{display:block;font-size:11px}.step-tabs button[aria-selected="true"]{background:var(--wash);color:var(--ink)}.step-tabs button[aria-selected="true"]:after{content:'';position:absolute;bottom:-1px;left:0;right:0;height:2px;background:var(--green)}.step-tabs button:focus-visible,.step-next:focus-visible{outline:2px solid var(--green);outline-offset:-4px}.step-panel{padding:17px 17px 0}.step-panel[hidden]{display:none}.step-panel .post-figure{margin:0}.step-panel .post-figure>a{border:0}.step-panel figcaption{padding-top:8px}.step-footer{display:flex;align-items:center;justify-content:space-between;gap:15px;padding:13px 17px 16px}.step-description{font-size:11px;line-height:1.8;color:var(--muted);margin:0}.step-next{white-space:nowrap;font-size:12px;min-height:40px;padding:0 3px 0 15px}.step-next span{margin-left:12px}

.source-panel{margin:34px 0 38px}.source-panel>a{display:block;background:white;border:1px solid var(--line);line-height:0}.source-panel svg{display:block;width:100%;height:auto}.source-panel figcaption,.source-experiment figcaption{color:var(--muted);font-size:10px;line-height:1.9;padding-top:11px}.source-panel figcaption a,.source-experiment figcaption a{color:var(--muted);text-decoration-color:var(--line)}
.source-experiment{margin:33px 0 42px}.source-toolbar{display:flex;align-items:center;justify-content:space-between;gap:15px;background:var(--wash);border:1px solid var(--line);border-bottom:0;padding:8px 13px;font-size:11px;line-height:1.7;color:var(--muted)}.source-window{width:100%;height:var(--scaled-height,400px);position:relative;background:#fff;border:1px solid var(--line);overflow:hidden}.source-window iframe{display:block;position:absolute;top:0;left:0;border:0;width:1280px;transform:scale(var(--source-scale,1));transform-origin:top left;background:white}.post-body>noscript{font-size:12px;color:var(--muted)}
@media(max-width:600px){.figure-pair{gap:10px;margin:28px 0 32px}.figure-pair figcaption{font-size:9px;line-height:1.7}.post-figure.figure-small{max-width:80%;margin:28px auto 32px}.step-tabs button{padding:12px 13px;font-size:12px}.step-tabs button span{font-size:10px}.step-panel{padding:11px 11px 0}.step-footer{padding:9px 11px 12px;gap:7px}.step-description{font-size:10px}.step-next{font-size:11px;padding-left:5px}.step-next span{margin-left:5px}.source-toolbar{padding:6px 10px}.source-panel,.source-experiment{margin:27px 0 33px}}

/* Keep the original interactive pages live, with room to explore at full size. */
.source-open,.source-close{font:inherit;cursor:pointer;border:0;background:transparent;color:var(--ink);min-height:36px;padding:0 8px;white-space:nowrap}.source-open:focus-visible,.source-close:focus-visible{outline:2px solid var(--green);outline-offset:2px}.source-help{font:12px/1.8 var(--sans);color:var(--muted);margin:0;padding:12px 14px;background:#f8faf3;border:1px solid var(--line);border-bottom:0}.source-dialog{width:calc(100vw - 36px);max-width:1500px;height:calc(100dvh - 36px);max-height:none;padding:0;border:1px solid var(--line);background:white;color:var(--ink);overflow:hidden}.source-dialog[open]{display:flex;flex-direction:column}.source-dialog::backdrop{background:rgba(22,35,23,.56)}.source-dialog-header{display:flex;align-items:center;justify-content:space-between;gap:16px;padding:10px 16px;background:var(--paper);border-bottom:1px solid var(--line);font:13px/1.6 var(--sans);flex-shrink:0}.source-dialog .source-help{line-height:22px;border:0;border-bottom:1px solid var(--line);flex-shrink:0}.source-dialog>iframe{display:block;border:0;flex:1;min-height:0;width:100%;background:white}.source-dialog-open{overflow:hidden}@media(max-width:600px){.source-dialog{width:calc(100vw - 12px);height:calc(100dvh - 12px)}.source-dialog-header{font-size:11px;padding:7px 9px;gap:6px}.source-help{font-size:11px;padding:10px}.source-dialog-header>span{max-width:75%}}

/* Author-approved heading palette B. */
.article-page{--chapter-heading:#36742a;--section-heading:#536b78;--method-heading:#328e41}
.article-page .post-body h2{color:var(--chapter-heading)}
.article-page .post-body h3{color:var(--section-heading)}
.article-page .post-body h4,.article-page .post-body h5,.article-page .post-body h6{color:var(--method-heading)}
@media(max-width:600px){.figure-pair{grid-template-columns:minmax(0,1fr);gap:22px}.figure-pair figcaption{font-size:10px}}