.blog-article{max-width:800px;padding-top:40px;padding-bottom:var(--article-tail, clamp(64px, 9vw, 120px))}.article-shell{--article-tail: clamp(64px, 9vw, 120px)}.blog-article a{text-underline-offset:4px}.blog-article a:focus-visible{outline:2px solid var(--color-ink);outline-offset:4px}.breadcrumb{margin-bottom:32px;font-size:15px;color:var(--color-text-secondary)}.article-heading h1{font-size:clamp(34px,5.5vw,52px);line-height:1.12;font-weight:800;overflow-wrap:anywhere}.article-heading .description{margin-top:24px;font-size:21px;line-height:1.55;color:var(--color-text-secondary)}.article-heading .byline{display:flex;flex-wrap:wrap;align-items:center;gap:8px 24px;margin-top:28px;font-size:15px}.article-heading .updated{margin-top:8px;font-size:14px;color:var(--color-text-secondary)}.article-hero{display:block;width:100%;height:auto;margin-top:32px;border-radius:6px}.blog-prose{margin-top:44px;font-size:18px;line-height:1.75;overflow-wrap:anywhere}.blog-prose>:first-child{margin-top:0}.blog-prose p,.blog-prose ul,.blog-prose ol{margin:1.25em 0}.blog-prose li+li{margin-top:.45em}.blog-prose h2{font-size:29px;line-height:1.25;margin:2em 0 .7em;scroll-margin-top:32px}.blog-prose h3{font-size:23px;line-height:1.3;margin:1.7em 0 .65em}.blog-prose h4,.blog-prose h5,.blog-prose h6{font-size:19px;margin:1.5em 0 .6em}.blog-prose blockquote{margin:1.5em 0;padding:.1em 0 .1em 24px;border-left:3px solid var(--color-ink);color:var(--color-text-secondary)}.blog-prose img{height:auto;margin:28px auto;border-radius:6px}.blog-prose code{font-size:.88em}.blog-prose pre{padding:20px;overflow-x:auto;border-radius:6px;line-height:1.6}.blog-prose pre code{overflow-wrap:normal}.blog-prose table{width:100%;border-collapse:collapse;margin:28px 0;font-size:16px;line-height:1.55}.blog-prose th,.blog-prose td{text-align:left;vertical-align:top;padding:14px 16px;border-bottom:1px solid var(--sand-200)}.blog-prose th[align=right],.blog-prose td[align=right]{text-align:right}.blog-prose th[align=center],.blog-prose td[align=center]{text-align:center}.blog-prose th{color:var(--color-ink);font-weight:600;border-top:1px solid var(--sand-200)}.blog-prose hr{margin:40px 0;border:0;border-top:1px solid var(--sand-200)}@media(max-width:520px){.blog-prose{font-size:17px}.blog-prose th,.blog-prose td{padding:10px 8px}.blog-prose table{font-size:14px}}.blog-prose .tldr{margin:36px 0 0;padding:18px 22px 20px;border:1px solid var(--sand-200);border-radius:6px;background:var(--color-panel);font-size:16.5px;line-height:1.65}.blog-prose .tldr-label{margin:0 0 10px;font-size:12.5px;font-weight:600;letter-spacing:.06em;text-transform:uppercase;color:var(--color-text-tertiary)}.blog-prose .tldr ul{margin:0;padding-left:1.15em}.blog-prose .tldr li+li{margin-top:.55em}@media(max-width:520px){.blog-prose .tldr{padding:14px 16px 16px;font-size:15.5px}}an <img> cannot be hovered into,and inline markup lets the drawing take its colours from the tokens below — so one drawing serves the page and the old light/dark image pair is gone. There is no theme swap here on purpose: blog pages have no automatic dark mode (no prefers-color-scheme anywhere in the CSS),and `data-theme` is a zone marker the landing page paints on itself. Do not reintroduce one. The `figure img` rule stays for any ordinary image a post may carry. */ .blog-prose figure{margin:32px 0}.blog-prose figure img{display:block;margin:0 auto;max-width:100%;height:auto}.blog-prose figure[id],.blog-prose #table-1{scroll-margin-top:96px}.blog-prose figcaption{margin-top:12px;font-size:16px;line-height:1.55;color:var(--color-text-secondary)}.blog-prose .tbl-cap{color:var(--color-text-secondary)}.fig-ui{margin:40px 0}.fig-ui-grid{display:grid;grid-template-columns:repeat(3,minmax(0,1fr));gap:20px}.fig-ui-shot{width:100%;cursor:zoom-in}.fig-ui-shot,.fig-lightbox-phone{position:relative;display:block;aspect-ratio:438 / 908;-webkit-user-select:none;user-select:none;border-radius:calc(80 / 438 * 100%) / calc(80 / 908 * 100%)}.fig-ui-shot ::selection,.fig-lightbox-phone ::selection{background:transparent}.fig-ui-shot:before,.fig-lightbox-phone:before{content:"";position:absolute;left:calc(14 / 438 * 100%);top:calc(13 / 908 * 100%);width:calc(410 / 438 * 100%);height:calc(882 / 908 * 100%);border-radius:calc(66 / 410 * 100%) / calc(66 / 882 * 100%);background:#000}.blog-prose .fig-ui-shot img,.fig-lightbox-phone img{position:absolute;left:calc(18 / 438 * 100%);top:calc(17 / 908 * 100%);width:calc(402 / 438 * 100%);max-width:none;height:auto;margin:0;border-radius:0;-webkit-mask:url(/blog/measuring-which-emails-need-you/ui/iphone-17-pro-screen.svg) 0 0 / 100% 100% no-repeat;mask:url(/blog/measuring-which-emails-need-you/ui/iphone-17-pro-screen.svg) 0 0 / 100% 100% no-repeat}.fig-ui-shot:after,.fig-lightbox-phone:after{content:"";position:absolute;inset:0;background:url(/blog/measuring-which-emails-need-you/ui/iphone-17-pro-frame.svg) 0 0 / 100% 100% no-repeat;pointer-events:none}@media(max-width:640px){.fig-ui-grid{grid-template-columns:repeat(2,minmax(0,1fr));gap:20px 16px}}.fig-lightbox-lock{overflow:hidden;scrollbar-gutter:stable}.fig-lightbox{position:fixed;inset:0;width:100%;height:100%;max-width:none;max-height:none;margin:0;padding:0;border:0;background:transparent;color:var(--cream-250);overflow:hidden;overscroll-behavior:contain;touch-action:pinch-zoom}.fig-lightbox::backdrop{background:#0f1611}.fig-lightbox[open]{display:grid;box-sizing:border-box;grid-template-columns:76px minmax(0,1fr) 76px;grid-template-rows:minmax(0,1fr) auto;grid-template-areas:"prev stage next" ". caption .";row-gap:14px;padding:max(20px,env(safe-area-inset-top)) max(8px,env(safe-area-inset-right)) max(20px,env(safe-area-inset-bottom)) max(8px,env(safe-area-inset-left))}.fig-lightbox-stage{grid-area:stage;min-height:0;container-type:size;display:grid;place-items:center}.fig-lightbox-phone{width:min(100cqw,100cqh * 438 / 908)}.fig-lightbox-full:not(.is-loaded){visibility:hidden}.fig-lightbox-caption{grid-area:caption;justify-self:center;align-self:center;max-width:60ch;margin:0;font-size:15px;line-height:1.5;text-align:center;text-wrap:balance}.fig-lightbox-count{margin-left:.5em;color:#f3f5ee9e;font-variant-numeric:tabular-nums;white-space:nowrap}.fig-lightbox-button{display:grid;place-items:center;width:44px;height:44px;padding:0;border:1px solid rgba(243,245,238,.22);border-radius:50%;background:#f3f5ee14;color:var(--cream-250);cursor:pointer}.fig-lightbox-button:hover{background:#f3f5ee2e}.fig-lightbox-button:focus-visible{outline:2px solid var(--cream-250);outline-offset:3px}.fig-lightbox-close{grid-area:next;justify-self:center;align-self:start}.fig-lightbox-prev{grid-area:prev;place-self:center}.fig-lightbox-next{grid-area:next;place-self:center}@media(max-width:640px){.fig-lightbox[open]{grid-template-columns:52px minmax(0,1fr) 52px;grid-template-rows:52px minmax(0,1fr) auto;grid-template-areas:". . close" "stage stage stage" "prev caption next";row-gap:10px;padding-top:max(8px,env(safe-area-inset-top));padding-inline:max(16px,env(safe-area-inset-left)) max(16px,env(safe-area-inset-right))}.fig-lightbox-close{grid-area:close;justify-self:end;align-self:center}.fig-lightbox-prev{justify-self:start}.fig-lightbox-next{justify-self:end}.fig-lightbox-caption{font-size:14px}}@keyframes fig-lightbox-fade{0%{opacity:0}}@keyframes fig-lightbox-grow{0%{opacity:0;transform:scale(.96)}}.fig-lightbox[open],.fig-lightbox[open]::backdrop{animation:fig-lightbox-fade .18s ease-out}.fig-lightbox[open] .fig-lightbox-phone{animation:fig-lightbox-grow .22s cubic-bezier(.2,.8,.2,1)}@media(prefers-reduced-motion:reduce){.fig-lightbox[open],.fig-lightbox[open]::backdrop,.fig-lightbox[open] .fig-lightbox-phone{animation:none}}.fig-interactive{margin:40px 0}@media(max-width:700px){.fig-interactive{max-width:100%}.fig-interactive .fig-chart{width:100%;max-width:100%}}.fig-chart{width:100%;height:auto}.fig-grid{stroke:var(--sand-200);stroke-width:1}.fig-ray{stroke:var(--sage-300);stroke-width:2.4;stroke-dasharray:9 6}.fig-axis{stroke:var(--sage-200);stroke-width:1.3}.fig-chart text{font-family:Switzer,-apple-system,BlinkMacSystemFont,sans-serif;fill:var(--color-text-secondary)}.fig-tick{font-size:14px;fill:var(--color-text-tertiary)}.fig-axlab{font-size:15px;fill:var(--color-text-secondary)}.fig-raylab{font-size:13px;fill:var(--color-text-tertiary)}.fig-floor{stroke:var(--color-text-tertiary);stroke-width:2.5;stroke-dasharray:10 7;opacity:1}.fig-floorlab{font-weight:700}.fig-floornote{opacity:.8}.fig-pt,.fig-ptname{opacity:0;pointer-events:none}.fig-ptname{font-weight:600;fill:var(--fig-c);paint-order:stroke;stroke:var(--color-canvas);stroke-width:4px}.fig-wrap.is-hot .fig-series.is-on .fig-pt,.fig-wrap.is-hot .fig-series.is-on .fig-ptname,.fig-chart .fig-series:hover .fig-pt,.fig-chart .fig-series:hover .fig-ptname{opacity:1}.fig-chart .fig-series:focus-visible .fig-pt,.fig-chart .fig-series:focus-visible .fig-ptname{opacity:1}.fig-note{font-size:14.5px;fill:var(--color-text-tertiary)}.fig-keylab{font-size:14.5px;fill:var(--color-text-secondary)}#figure-2 .fig-tick,#figure-3 .fig-tick{font-size:22px}#figure-2 .fig-axlab,#figure-3 .fig-axlab{font-size:23px}#figure-2 .fig-raylab,#figure-3 .fig-raylab{font-size:20px}#figure-2 .fig-note,#figure-2 .fig-keylab,#figure-2 .fig-ptname{font-size:22px}#figure-a1 .fig-barlab{font-size:24px;font-weight:600;fill:var(--color-text-secondary)}#figure-a1 .fig-segnum{font-size:22px;font-weight:700;fill:var(--color-text-secondary)}#figure-a1 .fig-keylab,#figure-a1 .fig-note{font-size:21px}#figure-a1 .fig-seg-d0{fill:var(--color-brand)}#figure-a1 .fig-seg-d1{fill:var(--ochre-500)}#figure-a1 .fig-seg-d2{fill:var(--sand-200)}#figure-a1 .fig-seg-c0{fill:var(--ochre-500)}.fig-chart .fig-series,.fig-chart .fig-key{--fig-c: var(--sage-400)}.fig-chart [data-group=local]{--fig-c: var(--color-brand)}.fig-chart [data-group=openai]{--fig-c: var(--ochre-500)}.fig-chart [data-group=anthropic]{--fig-c: var(--night-700)}.fig-track{stroke:var(--fig-c);stroke-width:2.2;stroke-linecap:round;stroke-linejoin:round}.fig-key circle{fill:var(--fig-c)}.fig-name{font-size:13.5px;font-weight:600;fill:var(--fig-c);opacity:0;pointer-events:none;paint-order:stroke;stroke:var(--color-canvas);stroke-width:4px;stroke-linejoin:round;transition:opacity .15s ease}.fig-series{opacity:.82;transition:opacity .15s ease;cursor:pointer}@media(hover:hover){.fig-chart:hover .fig-series{opacity:.16}.fig-chart:hover .fig-series:hover,.fig-chart:hover .fig-series:hover .fig-name{opacity:1}}.fig-chart:has(.fig-series:focus-visible) .fig-series{opacity:.16}.fig-chart:has(.fig-series:focus-visible) .fig-series:focus-visible{opacity:1}.fig-chart:has(.fig-series:focus-visible) .fig-series:focus-visible .fig-name{opacity:1}.fig-chart .fig-series:focus{outline:none}.fig-plain{margin:40px 0}.fig-slope{stroke:var(--sage-300);stroke-width:1.6}.fig-slope-jev{stroke:var(--matcha-500);stroke-width:3}.fig-colhead{font-family:ui-monospace,Menlo,monospace;font-size:15px;letter-spacing:.08em;fill:var(--color-text-secondary)}.fig-callout{font-size:21px;font-weight:600;fill:var(--color-text)}.fig-zone{fill:var(--color-panel);stroke:var(--sand-200);stroke-width:1.5}.fig-zonename{font-family:ui-monospace,Menlo,monospace;font-size:15px;letter-spacing:.08em;fill:var(--color-text-secondary)}.fig-zonenote{font-size:16px;fill:var(--color-text-tertiary)}.fig-node{fill:#fff;stroke:var(--sand-200);stroke-width:1.5}.fig-node-out{fill:var(--matcha-100);stroke:var(--matcha-500)}.fig-node-fit{fill:var(--ochre-tint);stroke:var(--ochre-500)}.fig-nodetitle{font-size:21px;font-weight:600;fill:var(--color-text)}.fig-nodesub{font-size:16px;fill:var(--color-text-secondary)}.fig-q{font-size:19px;fill:var(--color-text)}.fig-qp{font-family:ui-monospace,Menlo,monospace;font-size:15px;fill:var(--color-text-tertiary)}.fig-edge{fill:none;stroke:var(--sage-300);stroke-width:1.8}.fig-arrow{fill:var(--sage-300)}.fig-bar{fill:var(--sage-600)}.fig-bar-bad{fill:var(--sage-200)}.fig-bar-free{fill:var(--matcha-500)}.fig-steplab{font-size:22px;font-weight:600;fill:var(--color-text)}.fig-stepname{font-size:17px;fill:var(--color-text-secondary)}.fig-stepnote{font-size:15px;fill:var(--color-text-tertiary);font-style:italic}.fig-dot.fig-dot-alone{fill:var(--sage-200)}.fig-dot.fig-dot-harness{fill:var(--sage-600)}.fig-dot.fig-dot-jev{fill:var(--matcha-500)}.fig-span{stroke:var(--sage-200);stroke-width:2}.fig-span-jev{stroke:var(--matcha-500);stroke-width:2}.fig-leader{stroke:var(--sage-200);stroke-width:1.4}.fig-modellab{font-size:20px;fill:var(--color-text-tertiary)}.fig-modellab-jev{fill:var(--matcha-500);font-weight:600}.fig-pointlab{font-size:22px;fill:var(--color-text-secondary)}.fig-pointlab-jev{fill:var(--matcha-500);font-weight:600}.fig-dot.fig-keydot-alone{fill:var(--sage-200)}.fig-dot.fig-keydot-harness{fill:var(--sage-600)}#jev-figure-4 .fig-bar-m0{fill:var(--forest-800)}#jev-figure-4 .fig-bar-m1{fill:var(--sage-600)}#jev-figure-4 .fig-bar-m2{fill:var(--sage-500)}#jev-figure-4 .fig-bar-m3{fill:var(--sage-400)}#jev-figure-4 .fig-bar-m4{fill:var(--sage-300)}#jev-figure-4 .fig-bar-m5{fill:var(--sage-200)}#jev-figure-4 .fig-bar-jev{fill:var(--matcha-500)}#jev-figure-4 .fig-barval{font-size:16px;fill:var(--color-text-secondary)}#jev-figure-4 .fig-barval-jev{font-size:16px;fill:var(--matcha-500);font-weight:600}#jev-figure-4 .fig-legend{font-size:18px;fill:var(--color-text-secondary)}#jev-figure-4 .fig-legend-jev{font-size:18px;fill:var(--matcha-500);font-weight:600}#jev-figure-4 .fig-zonenote{font-size:18px}#jev-figure-1 .fig-tick,#jev-figure-2 .fig-tick{font-size:22px}#jev-figure-1 .fig-note,#jev-figure-2 .fig-note{font-size:21px}#jev-figure-1 .fig-keylab,#jev-figure-2 .fig-keylab{font-size:22px}@media(max-width:760px){.fig-plain .fig-chart{width:100%;max-width:100%}}.fig-wrap{display:grid;grid-template-columns:minmax(0,1fr) 284px;gap:6px;align-items:start}.fig-wrap-stacked{grid-template-columns:minmax(0,1fr)}.fig-wrap-stacked .fig-legend{grid-template-columns:repeat(3,minmax(0,1fr));margin-top:0;max-height:184px;overflow-y:auto;align-content:start;scrollbar-gutter:stable;padding-top:2px;mask-image:linear-gradient(to bottom,black calc(100% - 22px),transparent);-webkit-mask-image:linear-gradient(to bottom,black calc(100% - 22px),transparent)}.fig-wrap-stacked .fig-group{grid-column:auto!important;grid-row:auto!important}.fig-wrap-stacked .fig-group[data-group]{margin-top:0}.fig-wrap [data-group=openai]{--fig-c: var(--ochre-500)}.fig-wrap [data-group=anthropic]{--fig-c: var(--night-700)}.fig-wrap [data-group=local]{--fig-c: var(--color-brand)}.fig-series{opacity:.5;transition:opacity .12s ease}.fig-track{stroke:var(--fig-c);stroke-width:1.6;fill:none}.fig-dot{fill:var(--fig-c)}.fig-hit{stroke:transparent;stroke-width:15}.fig-legend{font-size:13px;line-height:1.3;display:grid;grid-template-columns:repeat(2,minmax(0,1fr));gap:2px 12px;align-items:start}.fig-group[data-group=openai]{grid-column:1;grid-row:1 / span 2}.fig-group[data-group=anthropic]{grid-column:2;grid-row:1}.fig-group[data-group=local]{grid-column:2;grid-row:2;margin-top:12px}.fig-grouphead{margin:0 0 5px;font-size:12.5px;letter-spacing:.05em;color:var(--color-text-tertiary);font-weight:600}.fig-grouphead span{opacity:.65;font-weight:400}.fig-legend ul{list-style:none;margin:0;padding:0}.fig-item{display:flex;align-items:center;gap:6px;padding:1px 4px;border-radius:3px;scroll-margin:32px 0;cursor:pointer;color:var(--color-text-secondary);transition:opacity .12s ease}.fig-swatch{width:9px;height:9px;border-radius:2px;background:var(--fig-c);flex:none}.fig-item:focus-visible{outline:2px solid var(--color-focus);outline-offset:1px}.fig-item.is-unusable{opacity:.55;cursor:default}.fig-item.is-unusable .fig-swatch{filter:grayscale(1)}.fig-item.is-unusable s{text-decoration-thickness:1px}.fig-wrap.is-hot .fig-series{opacity:.08}.fig-wrap.is-hot .fig-series.is-on{opacity:1}.fig-wrap.is-hot .fig-series.is-on .fig-track{stroke-width:3}.fig-wrap.is-hot .fig-item{opacity:.35}.fig-wrap.is-hot .fig-item.is-on{opacity:1;background:var(--color-panel);font-weight:600;color:var(--color-ink)}@media(max-width:760px){.fig-wrap{grid-template-columns:1fr}.fig-legend{grid-template-columns:repeat(2,minmax(0,1fr));font-size:11.5px}}.blog-prose details.appendix{margin:2em 0 0;border-top:1px solid var(--sand-200);border-bottom:1px solid var(--sand-200)}.blog-prose details.appendix>summary{display:flex;align-items:center;gap:16px;padding:20px 0;cursor:pointer;list-style:none}.blog-prose details.appendix>summary::-webkit-details-marker{display:none}.blog-prose details.appendix>summary h2{margin:0;scroll-margin-top:32px}.blog-prose details.appendix>summary:before{content:"";flex:none;width:11px;height:11px;margin-left:3px;border-right:2.5px solid var(--color-ink);border-bottom:2.5px solid var(--color-ink);transform:rotate(-45deg);transition:transform .15s ease}.blog-prose details.appendix[open]>summary:before{transform:rotate(45deg)}.blog-prose details.appendix>summary:hover h2{color:var(--color-text-secondary)}.blog-prose details.appendix>summary:focus-visible{outline:2px solid var(--color-ink);outline-offset:4px}.blog-prose details.appendix[open]>summary{padding-bottom:8px}@media(prefers-reduced-motion:reduce){.blog-prose details.appendix>summary:before{transition:none}}.article-toc-rail{display:none}@media(min-width:1200px){.article-shell{display:grid;grid-template-columns:minmax(0,1fr) minmax(0,800px) minmax(0,1fr);column-gap:32px}.article-shell>.blog-article{grid-column:2;grid-row:1;width:100%}.article-toc-rail{display:block;grid-column:1;grid-row:1;justify-self:end;width:100%;max-width:236px;padding-top:40px;margin-bottom:var(--article-tail)}.article-toc{position:sticky;top:32px;max-height:calc(100vh - 64px);overflow-y:auto;padding:2px 4px 2px 2px}.toc-reveal .article-toc:not([data-reveal=shown]){opacity:0;transform:translateY(-6px);visibility:hidden;pointer-events:none}.article-toc[data-animate]{transition:opacity .2s ease,transform .2s ease,visibility 0s linear 0s}.toc-reveal .article-toc[data-animate]:not([data-reveal=shown]){transition:opacity .2s ease,transform .2s ease,visibility 0s linear .2s}}.article-toc ol{list-style:none;margin:0;padding:0;border-left:1px solid var(--sand-200)}.article-toc li+li{margin-top:2px}.toc-link{display:block;margin-left:-1px;padding:6px 0 6px 16px;border-left:2px solid transparent;font-size:14px;line-height:1.45;color:var(--color-text-secondary);text-decoration:none;transition:color .12s ease,border-color .12s ease}.toc-link:hover{color:var(--color-ink)}.toc-link[aria-current]{color:var(--color-ink);border-left-color:var(--color-ink);font-weight:600}.toc-top{display:inline-flex;align-items:center;gap:6px;margin-top:20px;padding-left:17px;font-size:14px;font-weight:600;color:var(--color-text-secondary);text-decoration:none}.toc-top:hover{color:var(--color-ink)}.article-toc a:focus-visible{outline:2px solid var(--color-ink);outline-offset:2px;border-radius:2px}.blog-prose :is(h2,h3)[id]{scroll-margin-top:5rem}.section-copy{all:unset;display:inline-flex;width:1.15em;height:1.15em;margin-left:.35em;align-items:center;justify-content:center;vertical-align:-.12em;color:var(--color-text-tertiary);cursor:pointer;opacity:.5;transition:color .15s ease,opacity .15s ease}.section-copy svg{width:.78em;height:.78em}.section-copy:hover,.section-copy:focus-visible{color:var(--color-brand);opacity:1}.section-copy:focus-visible{border-radius:.2em;outline:2px solid currentColor;outline-offset:2px}.section-copy.is-copied{color:var(--matcha-600);opacity:1}@media(hover:hover)and (pointer:fine){.section-copy{opacity:0}.blog-prose :is(h2,h3):hover .section-copy,.section-copy:focus-visible,.section-copy.is-copied{opacity:1}}@media(prefers-reduced-motion:reduce){.section-copy{transition:none}}
