/* Design read: personal editorial companion. DESIGN_VARIANCE 6, MOTION_INTENSITY 3, VISUAL_DENSITY 3. Native CSS; coordinated self-hosted Plex typography. Layers: header 10, mobile navigation 20. */
:root{color-scheme:light dark;--bg:#f8f7f3;--paper:#fdfcf9;--ink:#282a2e;--muted:#636369;--line:#dbd8d1;--accent:#243f65;--soft:#ece9e2;--image:#efede7;--radius:8px;--ease-out:cubic-bezier(0.23,1,0.32,1);--ease-in-out:cubic-bezier(0.77,0,0.175,1);font-family:var(--site-font);background:var(--bg);color:var(--ink)}
@media(prefers-color-scheme:dark){:root{--bg:#202329;--paper:#272b33;--ink:#efede7;--muted:#bcc1cb;--line:#4a4f5a;--accent:#b2c7e6;--soft:#303642;--image:#d8d9dc}}
*{box-sizing:border-box}body{margin:0;font-size:17px;line-height:1.65}a{color:inherit;text-decoration-thickness:1px;text-underline-offset:5px}a:hover{color:var(--accent)}button{font:inherit;cursor:pointer}img{display:block;max-width:100%;height:auto}button,a{-webkit-tap-highlight-color:transparent}a:focus-visible,button:focus-visible{outline:3px solid var(--accent);outline-offset:5px}.skip{position:fixed;top:-100px;left:20px;background:var(--paper);padding:14px;z-index:30}.skip:focus{top:8px}.wrap{width:min(1280px,calc(100% - 96px));margin:auto}.header{border-bottom:1px solid var(--line);min-height:80px;display:flex;align-items:center;justify-content:space-between;gap:20px}.brand{font-weight:650;text-decoration:none;font-size:19px;letter-spacing:-.5px;white-space:nowrap}.brand span{color:var(--muted);font-size:14px;font-weight:400;display:block;letter-spacing:0;line-height:1.2}.nav{display:flex;align-items:center;gap:30px}.nav a{font-size:15px;text-decoration:none;white-space:nowrap}.nav a[aria-current=page]{text-decoration:underline;color:var(--accent)}.lang{border-left:1px solid var(--line);padding-left:23px;font-weight:600}.menu{display:none;color:var(--ink);background:none;border:1px solid var(--line);border-radius:var(--radius);padding:8px 15px;min-height:44px}.hero{display:grid;grid-template-columns:1.06fr 1fr;gap:64px;align-items:center;padding:76px 0 88px}.eyebrow{color:var(--accent);font-size:14px;font-weight:600;margin:0 0 22px}.hero h1{font-family:var(--site-font);font-size:clamp(48px,6.3vw,90px);font-weight:400;line-height:1.06;letter-spacing:-3.5px;margin:0 0 26px}.hero .intro{max-width:440px;font-size:19px;margin:0 0 30px;color:var(--muted)}.actions{display:flex;gap:22px;align-items:center;flex-wrap:wrap}.button{padding:12px 23px;min-height:48px;background:var(--accent);color:var(--bg);text-decoration:none;display:inline-block;border:1px solid var(--accent);border-radius:var(--radius);font-size:16px;font-weight:600;white-space:nowrap}.button:hover{color:var(--bg);filter:brightness(1.1)}.text-link{font-size:16px}.hero-art{background:var(--soft);border-radius:var(--radius);padding:28px 22px 22px;transform:rotate(1deg)}.hero-art img{width:100%;border:1px solid var(--line);border-radius:4px;box-shadow:0 12px 28px #1b2e4a15}.hero-art figcaption{font-size:13px;color:var(--muted);margin-top:14px}.hero-art figure{margin:0}.bridge{border-top:1px solid var(--line);border-bottom:1px solid var(--line);padding:46px 0;display:grid;grid-template-columns:1fr 1.35fr;gap:100px}.bridge h2{font-size:30px;line-height:1.25;font-weight:500;margin:0;max-width:330px}.bridge p{margin:0;max-width:630px;color:var(--muted)}section.block{padding:86px 0}h2{font-family:var(--site-font);font-size:clamp(30px,3.3vw,45px);font-weight:400;line-height:1.18;letter-spacing:-1px;margin:0 0 20px}h3{font-size:23px;line-height:1.35;font-weight:600;letter-spacing:-.4px;margin:0 0 12px}.section-head{margin-bottom:35px}.section-head p{max-width:670px;color:var(--muted);margin:0}.section-head a{display:inline-block;margin-top:16px}.projects{display:grid;grid-template-columns:1.15fr 1fr;gap:44px}.project{min-width:0}.project.wide{grid-column:1/-1;display:grid;grid-template-columns:1.13fr 1fr;align-items:center;gap:55px}.project figure{margin:0 0 22px;background:var(--image);padding:20px;border-radius:var(--radius)}.project img{aspect-ratio:1.65;object-fit:contain;width:100%}.project figcaption{color:#51525a;font-size:12px;margin-top:10px}.project h3 a{text-decoration:none}.project p{color:var(--muted);margin:0 0 18px;max-width:570px}.kind{font-size:14px;color:var(--accent);margin:0 0 8px!important}.project.small{border-top:1px solid var(--line);padding:24px 0 0}.notes{display:grid;grid-template-columns:1fr 1fr;gap:0 65px}.note{padding:27px 0;border-top:1px solid var(--line)}.note a{text-decoration:none}.note h3{font-size:25px;max-width:510px}.note p{color:var(--muted);margin:0}.note .read{color:var(--accent);font-size:14px;display:inline-block;margin-top:18px}.principles{display:grid;grid-template-columns:1fr 1fr;gap:35px 70px}.principle p{color:var(--muted);max-width:520px;margin:0}.learn-strip{background:var(--soft);padding:54px;border-radius:var(--radius);display:grid;grid-template-columns:1.2fr 1fr;gap:55px;align-items:center}.learn-strip p{color:var(--muted);max-width:540px;margin:0 0 20px}.footer{border-top:1px solid var(--line);padding:40px 0 35px;display:flex;justify-content:space-between;gap:30px;font-size:14px;color:var(--muted)}.footer p{margin:0}.footer a{white-space:nowrap}.page-head{padding:65px 0 55px;max-width:900px}.page-head h1{font-family:var(--site-font);font-weight:400;font-size:clamp(40px,5vw,68px);line-height:1.1;letter-spacing:-2px;margin:0 0 24px}.page-head p{max-width:690px;font-size:20px;color:var(--muted);margin:0}.back{display:inline-block;margin-bottom:28px;font-size:15px}.article-shell{display:grid;grid-template-columns:230px minmax(0,730px);gap:80px;padding:0 0 80px}.article-shell aside{font-size:14px;color:var(--muted);border-top:1px solid var(--line);padding-top:20px}.article-shell aside a{display:block;margin:12px 0}.prose h2{font-size:31px;margin:43px 0 18px}.prose h2:first-child{margin-top:0}.prose p{margin:0 0 23px;font-size:18px;line-height:1.85}.prose li{margin-bottom:14px}.prose figure{margin:35px 0}.prose figcaption{font-size:14px;color:var(--muted);margin-top:15px}.prose img{border:1px solid var(--line);border-radius:var(--radius)}.takeaway{background:var(--soft);padding:26px 30px;border-left:3px solid var(--accent);margin:35px 0}.takeaway p:last-child{margin-bottom:0}.share{border-top:1px solid var(--line);margin-top:50px;padding-top:25px}.share-controls{display:flex;flex-wrap:wrap;gap:10px}.share button,.share a{color:var(--ink);border:1px solid var(--line);background:var(--paper);border-radius:var(--radius);font-size:14px;min-height:44px;padding:8px 13px;text-decoration:none}.share p{font-size:14px;margin:10px 0}.status{padding:25px;background:var(--soft);font-size:16px}.learning-points{display:grid;grid-template-columns:1fr 1fr;gap:50px;margin:30px 0 75px}.learning-points p{color:var(--muted)}.notfound{text-align:center;padding:90px 0}.toc{padding:30px 0}.toc a{margin-right:22px}.zh h1,.zh h2{font-family:var(--site-font);letter-spacing:0;line-height:1.3}.zh .hero h1{font-size:clamp(43px,5.6vw,75px)}.zh .prose p{line-height:1.95}.zh .page-head h1{font-size:clamp(37px,4.7vw,62px)}
@media(max-width:1000px){.wrap{width:calc(100% - 48px)}.nav{gap:19px}.hero{gap:35px;padding:60px 0}.hero h1{letter-spacing:-2px}.article-shell{grid-template-columns:170px minmax(0,1fr);gap:40px}.bridge{gap:45px}.hero-art{padding:20px 14px 15px}.project.wide{gap:35px}}
@media(max-width:767px){.wrap{width:calc(100% - 36px)}.header{min-height:76px;position:relative}.menu{display:block}.nav{display:none;position:absolute;left:0;right:0;top:76px;z-index:20;background:var(--paper);border:1px solid var(--line);padding:20px;box-shadow:0 10px 20px #1b2e4a15}.nav.open{display:flex;flex-direction:column;align-items:stretch;gap:8px}.nav a{padding:8px 5px;min-height:44px;font-size:17px}.lang{border-left:0;border-top:1px solid var(--line);padding-top:15px!important}.hero{grid-template-columns:1fr;gap:42px;padding:43px 0 52px}.hero h1{font-size:57px;letter-spacing:-2.5px}.hero .intro{font-size:18px;max-width:380px}.hero-art{transform:none}.bridge{grid-template-columns:1fr;gap:20px;padding:32px 0}.bridge h2{max-width:100%;font-size:28px}.projects,.notes,.principles,.learning-points{grid-template-columns:1fr;gap:32px}.project.wide{grid-column:auto;display:block}.project figure{padding:12px}.project figcaption{font-size:12px}.block{padding:52px 0!important}.section-head{margin-bottom:27px}.learn-strip{grid-template-columns:1fr;gap:16px;padding:30px 25px}.learn-strip h2{font-size:32px}.footer{flex-direction:column;gap:18px;padding:30px 0}.page-head{padding:40px 0}.page-head h1{font-size:43px}.page-head p{font-size:18px}.article-shell{grid-template-columns:1fr;gap:25px}.article-shell aside{display:flex;flex-wrap:wrap;gap:10px 20px}.article-shell aside p{width:100%;margin:0}.article-shell aside a{margin:0}.prose p{font-size:17px}.prose h2{font-size:29px}.takeaway{padding:23px}.zh .hero h1{font-size:47px}.zh .page-head h1{font-size:38px}.actions{gap:18px}.notes{gap:0}}
@media(prefers-reduced-motion:no-preference){a,button{transition:color .16s,background-color .16s,transform .16s}.button:active{transform:translateY(1px)}.project a:hover img{transform:translateY(-2px)}img{transition:transform .2s}}
@media(max-width:767px){.en .hero h1{font-size:clamp(38px,11.5vw,47px);letter-spacing:-1.8px}}

.app-link{display:inline-block;color:var(--accent);font-weight:600;margin-left:24px}.case-app{margin:-25px 0 46px}.case-app .app-link{margin:0;padding:11px 20px;border:1px solid var(--accent);border-radius:var(--radius);text-decoration:none;min-height:48px}.case-app .app-link:hover{background:var(--soft)}@media(max-width:767px){.app-link{margin-left:0;display:block;margin-top:12px}.case-app{margin:-12px 0 35px}.case-app .app-link{display:inline-block}}
.page-head h1,.note h3{text-wrap:balance}

/* A visitor-controlled explanation; its final comparison also reads without JS. */
.save-explainer{padding:24px;border:1px solid var(--line);border-radius:var(--radius);background:#edf1f6}
.save-explainer [hidden]{display:none!important}
.save-explainer>figcaption{margin:0 0 24px;max-width:none;color:var(--ink);font-size:18px}
.save-explainer>figcaption strong,.save-explainer>figcaption span{display:block}
.save-explainer>figcaption span{color:var(--muted);font-size:14px;margin-top:5px}
.save-explainer-panels{display:grid;grid-template-columns:repeat(2,minmax(0,1fr));gap:16px}
.save-explainer-panels>div{padding:20px;background:var(--paper);border:1px solid var(--line);border-radius:var(--radius);min-width:0}
.save-explainer .save-panel-label{font-size:14px;line-height:1.5;color:var(--muted);margin:0 0 12px}
.save-explainer .save-version{font-size:18px;line-height:1.5;margin:0;min-block-size:2lh;font-weight:500;overflow-wrap:anywhere}
.save-explainer-track{position:relative;margin-top:24px;padding-bottom:8px;border-bottom:1px solid var(--line)}
.save-explainer-track ol{list-style:none;display:grid;grid-template-columns:repeat(4,minmax(0,1fr));padding:0;margin:0}
.save-explainer-track li{display:flex;min-width:0;margin:0;position:relative}
.save-explainer-track button{display:block;width:100%;padding:8px 3px;min-height:44px;background:none;border:0;border-radius:4px;color:var(--muted);font-size:14px;line-height:1.5;overflow-wrap:anywhere;transition:none}
.save-explainer-track button span{display:block;font-size:16px;margin-bottom:5px}
.save-explainer-track [aria-current=step],.save-explainer-track [data-current] .save-step-static{color:var(--accent);font-weight:500}
.save-step-static{display:block;padding:8px 3px;font-size:14px;line-height:1.5;color:var(--muted)}
.save-track-marker{position:absolute;left:0;bottom:-1px;width:25%;height:3px;background:var(--accent);transition:transform 220ms var(--ease-in-out)}
.save-track-marker[data-instant]{transition:none}
.save-explainer .save-explainer-status{font-size:16px;line-height:1.7;min-block-size:2lh;margin:22px 0 0}
.save-explainer-actions{display:flex;flex-wrap:wrap;gap:12px;margin-top:18px}
.save-explainer-actions button{min-height:44px;padding:8px 14px;border:1px solid var(--accent);border-radius:var(--radius);font-size:15px;background:var(--paper);color:var(--accent);transition:none}
.save-explainer-actions button[data-save-next]{background:var(--accent);color:var(--bg)}
.save-explainer-actions button:disabled{opacity:.5;cursor:default}
@media(max-width:599px){.save-explainer-panels{grid-template-columns:minmax(0,1fr)}.save-explainer .save-explainer-status{min-block-size:3lh}}
@media(prefers-color-scheme:dark){.save-explainer{background:var(--soft)}}
@media(prefers-reduced-motion:reduce){.save-track-marker{transition:none}}

/* Enhanced mobile navigation stays rendered so reversals retarget its transition. */
@media(max-width:767px){
 .nav[data-menu-enhanced]{display:flex;flex-direction:column;align-items:stretch;gap:8px;visibility:hidden;opacity:0;transform:translateY(-6px);pointer-events:none;transition:opacity var(--menu-duration,180ms) var(--ease-out),transform var(--menu-duration,180ms) var(--ease-out)}
 .nav[data-menu-enhanced].open{visibility:visible;opacity:1;transform:translateY(0);pointer-events:auto}
 .nav[data-menu-enhanced][data-closing]{visibility:visible}
 .nav[data-menu-enhanced][data-menu-instant]{transition:none}
}
@media(max-width:767px) and (prefers-reduced-motion:reduce){.nav[data-menu-enhanced]{transform:none;transition-property:opacity;transition-duration:80ms}.nav[data-menu-enhanced].open{transform:none}}
.share [data-share-status]{min-block-size:3lh}