:root{
 --ink:#111827;--teal:#0f766e;--teal-dark:#0b5f59;--mint:#ecfdf5;--slate:#475569;--muted:#64748b;
 --paper:#ffffff;--line:#dbe4ea;--soft:#f6f8fa;--warm:#fff8e8;--danger:#9f1239;--radius:20px;
 --shadow:0 18px 50px rgba(15,23,42,.08);--max:1160px;
}
*{box-sizing:border-box} html{scroll-behavior:smooth} body{margin:0;font-family:Inter,ui-sans-serif,system-ui,-apple-system,BlinkMacSystemFont,"Segoe UI",sans-serif;color:var(--ink);background:var(--paper);line-height:1.7;-webkit-font-smoothing:antialiased}
a{color:var(--teal-dark);text-decoration-thickness:.08em;text-underline-offset:.18em}a:hover{color:var(--teal)}
.skip-link{position:absolute;left:-999px;top:8px;background:#fff;padding:.65rem 1rem;z-index:1000;border:2px solid var(--teal)}.skip-link:focus{left:8px}
.site-header{position:sticky;top:0;z-index:50;background:rgba(255,255,255,.93);backdrop-filter:blur(14px);border-bottom:1px solid rgba(219,228,234,.85)}
.header-inner{max-width:var(--max);margin:auto;padding:.8rem 1.25rem;display:flex;align-items:center;justify-content:space-between;gap:1rem}.brand{display:flex;align-items:center;gap:.7rem;color:var(--ink);text-decoration:none;font-weight:800;letter-spacing:-.02em}.brand svg{width:34px;height:34px}.brand small{display:block;color:var(--muted);font-weight:600;font-size:.67rem;letter-spacing:.08em;text-transform:uppercase}
.nav-toggle{display:none;border:1px solid var(--line);background:#fff;border-radius:12px;padding:.55rem .65rem;font:inherit}.nav-list{display:flex;align-items:center;gap:.25rem;list-style:none;margin:0;padding:0}.nav-list a{display:block;padding:.48rem .65rem;border-radius:10px;color:var(--slate);text-decoration:none;font-size:.9rem;font-weight:650}.nav-list a:hover,.nav-list a[aria-current="page"]{background:var(--mint);color:var(--teal-dark)}
main{min-height:70vh}.hero{background:linear-gradient(135deg,#f7fffc 0%,#eefbf7 52%,#f8fafc 100%);border-bottom:1px solid var(--line)}.hero-grid{max-width:var(--max);margin:auto;padding:5rem 1.25rem 4.5rem;display:grid;grid-template-columns:1.05fr .95fr;align-items:center;gap:3.6rem}.eyebrow{display:inline-flex;align-items:center;gap:.45rem;color:var(--teal-dark);font-weight:800;font-size:.78rem;letter-spacing:.1em;text-transform:uppercase;background:#dff8ef;border:1px solid #b6ead8;border-radius:999px;padding:.38rem .7rem}.hero h1,.page-hero h1{font-size:clamp(2.3rem,5.5vw,4.7rem);line-height:1.02;letter-spacing:-.055em;margin:.9rem 0 1.15rem;max-width:900px}.hero p{font-size:1.12rem;color:var(--slate);max-width:720px}.hero-actions{display:flex;flex-wrap:wrap;gap:.75rem;margin-top:1.5rem}.btn{display:inline-flex;align-items:center;justify-content:center;gap:.4rem;border-radius:12px;padding:.8rem 1rem;text-decoration:none;font-weight:800}.btn-primary{background:var(--teal);color:#fff}.btn-primary:hover{background:var(--teal-dark);color:#fff}.btn-secondary{background:#fff;border:1px solid var(--line);color:var(--ink)}
.hero-media{position:relative}.hero-media img{display:block;width:100%;aspect-ratio:1/1;object-fit:cover;border-radius:28px;box-shadow:var(--shadow)}.hero-badge{position:absolute;right:-12px;bottom:22px;background:#fff;border:1px solid var(--line);box-shadow:var(--shadow);border-radius:16px;padding:.85rem 1rem;font-weight:750;max-width:230px}.hero-badge span{display:block;color:var(--teal);font-size:.78rem;text-transform:uppercase;letter-spacing:.08em}
.page-hero{background:linear-gradient(180deg,#f8fffc,#fff);border-bottom:1px solid var(--line)}.page-hero-inner{max-width:var(--max);margin:auto;padding:3.15rem 1.25rem 2.55rem}.page-hero h1{font-size:clamp(2.15rem,4.15vw,3.65rem);line-height:1.04;max-width:980px}.page-hero .lede{font-size:1.08rem;color:var(--slate);max-width:800px}.breadcrumbs{font-size:.82rem;color:var(--muted);margin-bottom:.8rem}.breadcrumbs a{color:var(--muted)}
.section{max-width:var(--max);margin:auto;padding:4rem 1.25rem}.cards{display:grid;grid-template-columns:repeat(3,1fr);gap:1rem}.card{border:1px solid var(--line);border-radius:var(--radius);padding:1.35rem;background:#fff}.card h3{margin:.2rem 0 .5rem}.card p{margin:.3rem 0;color:var(--slate)}.card-icon{width:42px;height:42px;border-radius:12px;background:var(--mint);display:grid;place-items:center;color:var(--teal);font-weight:900}
.article-shell{max-width:var(--max);margin:auto;padding:2.9rem 1.25rem 5rem;display:grid;grid-template-columns:minmax(0,770px) 250px;gap:3.6rem;align-items:start}.article{min-width:0}.article h2{font-size:clamp(1.5rem,2.35vw,2rem);line-height:1.2;letter-spacing:-.03em;margin:2.55rem 0 .85rem;scroll-margin-top:105px}.article h3{font-size:1.2rem;margin:1.9rem 0 .6rem;scroll-margin-top:105px}.article p,.article li{color:#263244}.article > p:first-of-type{font-size:1.1rem;color:var(--slate)}.article blockquote{margin:1.4rem 0;padding:1rem 1.15rem;border-left:4px solid var(--teal);background:var(--mint);border-radius:0 14px 14px 0}.article table{width:100%;border-collapse:separate;border-spacing:0;margin:1.5rem 0;border:1px solid var(--line);border-radius:16px;overflow:hidden;font-size:.93rem}.article th,.article td{padding:.75rem .8rem;border-bottom:1px solid var(--line);vertical-align:top}.article th{background:#f1f8f6;text-align:left}.article tr:last-child td{border-bottom:0}.article code{background:var(--soft);border:1px solid var(--line);border-radius:6px;padding:.08em .3em}.article img{max-width:100%}
.toc{position:sticky;top:82px;border-left:1px solid var(--line);padding:.15rem .65rem .15rem 1rem;max-height:calc(100vh - 108px);overflow:auto;scrollbar-width:thin;scrollbar-color:#cbd5e1 transparent}.toc strong{display:block;font-size:.76rem;text-transform:uppercase;letter-spacing:.09em;margin-bottom:.55rem;color:var(--muted)}.toc a{display:block;text-decoration:none;color:var(--slate);padding:.18rem 0;font-size:.81rem;line-height:1.28}.toc a:hover{color:var(--teal)}
.callout{border:1px solid #b8e6d8;background:var(--mint);border-radius:18px;padding:1.2rem 1.35rem;margin:1.5rem 0}.callout strong{color:var(--teal-dark)}.callout.warning{background:var(--warm);border-color:#f4d889}.callout.warning strong{color:#854d0e}.callout.danger{background:#fff1f2;border-color:#fecdd3}.callout.danger strong{color:var(--danger)}
.figure-card{margin:2rem 0;border:1px solid var(--line);border-radius:22px;overflow:hidden;background:#fff;box-shadow:0 12px 35px rgba(15,23,42,.05)}.figure-card img{width:100%;display:block;max-height:540px;object-fit:cover}.figure-card figcaption{padding:.75rem 1rem;color:var(--muted);font-size:.86rem}.image-grid{display:grid;grid-template-columns:1fr 1fr;gap:1rem;margin:1.7rem 0}.image-grid .figure-card{margin:0}
.module{margin:2rem 0;border-radius:22px;padding:1.5rem;border:1px solid var(--line);background:linear-gradient(145deg,#fff,#f8fbfa)}.module h2,.module h3{margin-top:0}.boundary-grid{display:grid;grid-template-columns:repeat(4,1fr);gap:.8rem}.boundary-step{padding:1rem;border-radius:16px;background:#fff;border:1px solid var(--line)}.boundary-step b{display:block;color:var(--teal);font-size:.8rem;text-transform:uppercase;letter-spacing:.07em}.boundary-step span{display:block;font-weight:800;margin:.15rem 0 .35rem}
.selector{background:#0f172a;color:#fff}.selector h2,.selector p{color:#fff}.selector-options{display:flex;flex-wrap:wrap;gap:.6rem;margin:1rem 0}.selector button{border:1px solid #475569;background:#1e293b;color:#fff;border-radius:12px;padding:.7rem .9rem;cursor:pointer;font:inherit;font-weight:700}.selector button:hover,.selector button:focus{background:#0f766e;outline:2px solid #99f6e4;outline-offset:2px}.selector-output{margin-top:1rem;padding:1rem;border-radius:14px;background:#fff;color:var(--ink);min-height:74px}.selector-output strong{color:var(--teal-dark)}
.ladder{display:grid;gap:.75rem;margin:1.5rem 0}.ladder-item{display:grid;grid-template-columns:62px 1fr;gap:1rem;align-items:start;border:1px solid var(--line);border-radius:16px;padding:1rem}.ladder-num{width:48px;height:48px;border-radius:14px;background:var(--mint);display:grid;place-items:center;color:var(--teal);font-weight:900}.ladder-item h3{margin:.1rem 0 .25rem}
.faq-list details{border:1px solid var(--line);border-radius:14px;margin:.7rem 0;background:#fff}.faq-list summary{cursor:pointer;font-weight:800;padding:1rem 1.1rem}.faq-list details>div{padding:0 1.1rem 1rem;color:var(--slate)}
.related{border-top:1px solid var(--line);margin-top:3rem;padding-top:2rem}.related-grid{display:grid;grid-template-columns:repeat(3,1fr);gap:.8rem}.related a{display:block;border:1px solid var(--line);border-radius:14px;padding:1rem;text-decoration:none;color:var(--ink);font-weight:750}.related a:hover{background:var(--mint);border-color:#b6ead8}
.site-footer{border-top:1px solid var(--line);background:#0f172a;color:#cbd5e1}.footer-inner{max-width:var(--max);margin:auto;padding:3rem 1.25rem;display:grid;grid-template-columns:1.2fr .8fr .8fr;gap:2rem}.site-footer a{color:#d7fff2}.site-footer p{color:#aab8ca}.footer-title{color:#fff;font-weight:900;font-size:1.05rem}.footer-links{list-style:none;padding:0;margin:0}.footer-links li{margin:.35rem 0}.footer-bottom{max-width:var(--max);margin:auto;padding:1rem 1.25rem;border-top:1px solid #273449;color:#8fa0b7;font-size:.82rem}
.badge-row{display:flex;flex-wrap:wrap;gap:.55rem;margin-top:1rem}.mini-badge{font-size:.78rem;font-weight:750;border-radius:999px;padding:.4rem .65rem;border:1px solid var(--line);background:#fff;color:var(--slate)}
.concept-panel{display:grid;grid-template-columns:240px 1fr;gap:1.4rem;align-items:center}.concept-device{border:2px solid #0f766e;border-radius:18px;padding:1rem;background:#ecfdf5;display:grid;grid-template-columns:1fr 1fr;gap:.65rem}.concept-screen{grid-column:1/-1;background:#0f172a;color:#fff;border-radius:10px;padding:1.1rem;text-align:center;font-weight:850}.concept-user{background:#fff;border:1px solid #b6ead8;border-radius:10px;padding:.65rem;text-align:center;font-weight:750}.data-map-grid{display:grid;grid-template-columns:1fr auto 1fr auto 1fr;gap:.7rem;align-items:center}.data-map-grid>div:not(.arrow){background:#fff;border:1px solid var(--line);border-radius:14px;padding:1rem}.data-map-grid b,.data-map-grid span{display:block}.data-map-grid span{color:var(--slate);font-size:.9rem;margin-top:.25rem}.data-map-grid .arrow{font-size:1.6rem;color:var(--teal);font-weight:900}

/* V1.1 FAQ scanability */
.faq-article h2{border-top:1px solid var(--line);padding-top:1.55rem;margin-top:1.65rem;font-size:clamp(1.48rem,2.15vw,1.88rem)}
.faq-article h2:first-child{border-top:0;padding-top:0;margin-top:0}
.faq-article h2 + p{margin-top:.25rem}
.faq-article p + p{margin-top:.8rem}
.faq-page .toc a{font-size:.79rem;padding:.14rem 0;line-height:1.24}
.faq-page .toc{max-height:calc(100vh - 102px)}

@media(max-width:980px){.nav-toggle{display:block}.nav-list{display:none;position:absolute;left:1rem;right:1rem;top:66px;flex-direction:column;align-items:stretch;background:#fff;border:1px solid var(--line);border-radius:16px;padding:.6rem;box-shadow:var(--shadow)}.nav-list.is-open{display:flex}.nav-list a{padding:.75rem}.hero-grid{grid-template-columns:1fr;padding-top:3.5rem}.hero-media{max-width:680px}.article-shell{grid-template-columns:1fr;gap:1rem}.toc{position:static;border-left:0;border:1px solid var(--line);border-radius:14px;padding:1rem;order:-1;max-height:none;overflow:visible}.boundary-grid{grid-template-columns:1fr 1fr}.concept-panel{grid-template-columns:1fr}.data-map-grid{grid-template-columns:1fr}.data-map-grid .arrow{transform:rotate(90deg);text-align:center}.footer-inner{grid-template-columns:1fr 1fr}}
@media(max-width:680px){.hero-grid,.section,.article-shell,.page-hero-inner{padding-left:1rem;padding-right:1rem}.hero-grid{padding-bottom:3rem}.hero h1,.page-hero h1{font-size:2.35rem}.cards,.related-grid,.image-grid,.footer-inner{grid-template-columns:1fr}.boundary-grid{grid-template-columns:1fr}.hero-badge{position:static;margin-top:.75rem}.article table{display:block;overflow-x:auto;white-space:normal}.header-inner{padding:.7rem 1rem}}
@media(prefers-reduced-motion:reduce){html{scroll-behavior:auto}*{transition:none!important;animation:none!important}}
:focus-visible{outline:3px solid #14b8a6;outline-offset:3px}


/* V1.2 editorial image enrichment */
.editorial-figure{margin:1.8rem 0 2.2rem;border:1px solid var(--line);border-radius:20px;overflow:hidden;background:#fff;box-shadow:0 12px 30px rgba(15,23,42,.055)}
.editorial-figure img{display:block;width:100%;height:auto;max-height:520px;object-fit:cover;background:#f8fafc}
.editorial-figure.contain img{object-fit:contain;padding:1rem;max-height:500px}
.editorial-figure figcaption{padding:.72rem .95rem;color:var(--muted);font-size:.84rem;line-height:1.45;border-top:1px solid var(--line)}
@media(max-width:680px){.editorial-figure{margin:1.4rem 0 1.8rem;border-radius:16px}.editorial-figure img{max-height:390px}.editorial-figure.contain img{max-height:360px;padding:.7rem}}