:root{--blue:#087ff5;--ink:#071d49;--navy:#06223b;--muted:#526a83;--line:#dce6ef;--pale:#f3f8fc}*{box-sizing:border-box}html{scroll-behavior:smooth;scroll-padding-top:88px}body{margin:0;color:var(--ink);background:#fff;font-family:Inter,-apple-system,BlinkMacSystemFont,"Segoe UI",Arial,sans-serif}a{color:inherit;text-decoration:none}a:hover{color:var(--blue)}a:focus-visible,summary:focus-visible{outline:3px solid #52aeff;outline-offset:5px}.skip{position:absolute;left:20px;top:-100px;z-index:100;background:white;padding:12px}.skip:focus{top:10px}.top{height:64px;background:#fff;border-bottom:1px solid var(--line);position:sticky;top:0;z-index:20}.top-in{max-width:1480px;margin:auto;padding:0 28px;height:100%;display:flex;align-items:center;gap:24px}.logo{display:flex;align-items:center;gap:10px;margin-right:auto;white-space:nowrap;font-size:20px}.logo i{width:27px;height:27px;border:6px dotted #174879;border-radius:50%}.top nav{display:flex;gap:20px;font-size:12px;white-space:nowrap}.actions{display:flex;gap:10px}.btn{display:inline-flex;justify-content:center;align-items:center;padding:12px 18px;border-radius:6px;font-size:13px;font-weight:600;border:1px solid var(--line)}.btn.blue{background:var(--blue);color:#fff;border-color:var(--blue)}.btn.light{border-color:#66829c;color:white}.btn:hover{filter:brightness(1.08)}.wrap{width:min(1180px,calc(100% - 64px));margin-inline:auto}.crumb{padding:20px 0;font-size:12px;color:var(--muted)}.crumb span{padding:0 8px;color:#8ba0b2}.hero{color:#fff;background:linear-gradient(115deg,#051c33,#0b3356);position:relative;overflow:hidden}.hero .wrap{padding-block:44px 38px}.eyebrow{font-size:11px;letter-spacing:.16em;text-transform:uppercase;color:#77bfff;font-weight:600;margin:0 0 18px}.hero h1{font-size:clamp(36px,4.2vw,56px);line-height:1.06;letter-spacing:-.035em;margin:0 0 22px;max-width:940px}.hero h1 em{font-style:normal;color:#78c4ff}.hero .lead{max-width:790px;color:#dbe8f3;font-size:18px;line-height:1.6;margin:0}.hero-foot{display:flex;align-items:center;justify-content:space-between;gap:30px;border-top:1px solid #36536e;margin-top:30px;padding-top:22px;font-size:12px;color:#adc8de}.hero-foot .links{display:flex;gap:12px}.hero-foot .topics{display:flex;gap:26px}.topics b{color:#75bfff;margin-right:9px;font-size:10px}.section{padding-block:58px}.section+.section{border-top:1px solid var(--line)}.section-label{font-size:11px;font-weight:650;letter-spacing:.13em;text-transform:uppercase;color:var(--blue);margin:0 0 14px}.section h2{font-size:32px;letter-spacing:-.025em;line-height:1.18;margin:0 0 20px}.section h3{font-size:19px;line-height:1.35;margin:0 0 12px}p{font-size:16px;line-height:1.75;margin:0 0 18px;color:#2c4966}p:last-child{margin-bottom:0}.intro-grid{display:grid;grid-template-columns:.8fr 1.2fr;gap:70px}.intro-grid .large{font-size:22px;line-height:1.5;color:var(--ink)}.technical-list{margin:0}.technical-list>div{display:grid;grid-template-columns:40px 175px 1fr;gap:20px;padding:22px 0;border-top:1px solid var(--line);align-items:start}.technical-list dt{font-size:17px;font-weight:650;line-height:1.4}.technical-list dd{margin:0;color:#36516c;font-size:15px;line-height:1.65}.technical-list>div::before{content:attr(data-number);color:var(--blue);font-size:12px;font-weight:700;padding-top:5px}.soft{background:var(--pale)}.band{background:var(--navy);color:#fff;padding-block:38px}.band .wrap{display:grid;grid-template-columns:.8fr 1.2fr;gap:70px;align-items:start}.band h2{font-size:30px;line-height:1.15;letter-spacing:-.02em;margin:0}.band em{font-style:normal;color:#79c7ff}.band p{color:#d1e1ed}.note{border-left:3px solid var(--blue);padding:20px 24px;background:var(--pale);font-size:15px;line-height:1.65}.note b{display:block;margin-bottom:6px}.note p{font-size:15px}.scenarios{counter-reset:scene}.scenario{padding:25px 0;border-top:1px solid #cbdbe8;display:grid;grid-template-columns:50px .85fr 1.4fr;gap:20px}.scenario::before{counter-increment:scene;content:"0" counter(scene);color:var(--blue);font-size:24px;font-weight:600}.scenario h3{margin:0}.scenario p{font-size:15px}.columns{display:grid;grid-template-columns:1fr 1fr;gap:54px}.plain-list{padding-left:20px;color:#36516c;font-size:15px;line-height:1.7}.plain-list li{padding:5px 0}.table-scroll{overflow-x:auto;border:1px solid var(--line);border-radius:8px;margin:25px 0}.table-scroll:focus-visible{outline:2px solid var(--blue)}table{width:100%;border-collapse:collapse;font-size:14px;line-height:1.55;text-align:left}caption{text-align:left;font-size:12px;padding:14px 18px;background:#fff;color:var(--muted)}th,td{padding:16px 18px;border-bottom:1px solid var(--line);vertical-align:top}thead th{background:#edf5fb;font-size:12px;color:#274c70}tbody th{font-weight:600;min-width:135px}tr:last-child>*{border-bottom:0}.table-scroll .tag{font-size:11px;display:inline-block;background:#e6f3ff;border-radius:4px;padding:3px 6px;color:#1166a9}.passport{display:grid;grid-template-columns:1fr 1fr 1fr;gap:0;border-block:1px solid var(--line);margin-top:28px}.passport div{padding:22px;border-right:1px solid var(--line)}.passport div:first-child{padding-left:0}.passport div:last-child{border:0}.passport b{display:block;font-size:27px;margin-bottom:8px}.passport span{font-size:13px;line-height:1.6;color:var(--muted)}.figure{margin:28px 0;background:#f1f7fb;border:1px solid var(--line);border-radius:10px;padding:26px}.figure svg{width:100%;height:auto;display:block}.figure figcaption{font-size:12px;line-height:1.6;color:var(--muted);margin-top:18px;max-width:850px}.svg-text{font-family:Inter,Arial,sans-serif;fill:#173b5e}.timeline{display:grid;grid-template-columns:repeat(3,1fr);gap:30px;margin-top:28px}.timeline>div{border-top:2px solid #91bde0;padding-top:18px}.timeline b{display:block;margin-bottom:9px;font-size:16px}.timeline p{font-size:14px}.end-links{display:flex;justify-content:space-between;align-items:center;gap:25px;padding-block:30px;border-top:1px solid var(--line)}.end-links div{font-size:13px;color:var(--muted)}.end-links a{font-size:14px;color:var(--blue);font-weight:600}.footer{border-top:1px solid var(--line);padding-block:25px 32px;color:var(--muted);font-size:12px}.footer .wrap{display:flex;justify-content:space-between;gap:20px}.footer nav{display:flex;gap:22px}.article-hero{background:#eef5fa;color:var(--ink);border-bottom:1px solid var(--line)}.article-hero .eyebrow{color:#1468a7}.article-hero .lead{color:#36516c}.article-hero h1{max-width:1000px}.article-hero .hero-foot{border-color:#cbdce9;color:var(--muted)}.article-layout{display:grid;grid-template-columns:225px minmax(0,1fr);gap:65px;padding-block:48px}.toc{align-self:start;position:sticky;top:95px;font-size:13px;line-height:1.5}.toc b{font-size:11px;letter-spacing:.12em;display:block;margin-bottom:14px;text-transform:uppercase;color:var(--muted)}.toc a{display:block;padding:10px 0;border-bottom:1px solid var(--line)}.article{max-width:830px;min-width:0}.article section{padding:0 0 38px;margin-bottom:38px;border-bottom:1px solid var(--line)}.article h2{font-size:29px;line-height:1.25;letter-spacing:-.02em;margin:0 0 20px}.article h3{font-size:20px;margin:28px 0 12px}.article p{font-size:17px;line-height:1.8}.article .note p{font-size:15px}.checklist{list-style:none;padding:0;counter-reset:check}.checklist li{counter-increment:check;position:relative;padding:14px 0 14px 45px;border-top:1px solid var(--line);font-size:15px;line-height:1.7;color:#36516c}.checklist li::before{content:counter(check,decimal-leading-zero);position:absolute;left:0;top:16px;font-size:12px;font-weight:700;color:var(--blue)}.metric-example{display:flex;gap:25px;align-items:baseline;margin:20px 0}.metric-example b{font-size:38px;letter-spacing:-.04em;color:var(--blue)}.metric-example span{font-size:13px;color:var(--muted)}.chart-grid{display:grid;grid-template-columns:1.15fr 1fr;gap:45px;align-items:center}.chart-grid .figure{margin:0}.chart-grid p{font-size:15px}.kicker-line{font-size:13px;color:var(--blue);margin-bottom:24px}.tech-index{display:flex;gap:20px;flex-wrap:wrap;padding:20px 0;border-bottom:1px solid var(--line);font-size:12px;color:var(--muted)}
@media(max-width:1150px){.top nav{gap:12px;font-size:11px}.top-in{gap:15px;padding-inline:22px}.logo{font-size:18px}.actions .btn{padding:10px 12px}.intro-grid,.band .wrap{gap:40px}}
@media(max-width:1000px){.top nav{display:none}.intro-grid,.band .wrap{grid-template-columns:1fr;gap:22px}.article-layout{grid-template-columns:180px minmax(0,1fr);gap:35px}.scenario{grid-template-columns:35px 1fr}.scenario p{grid-column:2}.chart-grid{grid-template-columns:1fr}.technical-list>div{grid-template-columns:30px 145px 1fr;gap:15px}}
@media(max-width:700px){.wrap{width:calc(100% - 36px)}.top-in{padding-inline:18px}.actions .btn:not(.blue){display:none}.logo{font-size:16px}.hero .wrap{padding-block:34px 28px}.hero h1{font-size:36px}.hero .lead{font-size:16px}.hero-foot{align-items:flex-start;flex-direction:column;gap:18px}.hero-foot .topics{gap:14px;flex-wrap:wrap}.section{padding-block:38px}.section h2,.band h2{font-size:27px}.columns,.timeline,.article-layout{grid-template-columns:1fr;gap:25px}.technical-list>div{grid-template-columns:27px 1fr;gap:12px}.technical-list dd{grid-column:2}.passport{grid-template-columns:1fr}.passport div,.passport div:first-child{padding:16px 0;border-right:0;border-bottom:1px solid var(--line)}.passport b{font-size:24px}.figure{padding:12px}.diagram-scroll{overflow-x:auto}.diagram-scroll svg{min-width:740px}.article-layout{padding-block:28px}.toc{position:static}.article h2{font-size:26px}.article p{font-size:16px}.end-links{align-items:flex-start;flex-direction:column}.footer .wrap{flex-direction:column}.metric-example b{font-size:30px}th,td{padding:12px}.table-scroll table{min-width:580px}.hero-foot .links{flex-wrap:wrap}}
@media(prefers-reduced-motion:reduce){html{scroll-behavior:auto}}

/* Visual finish: isolated to the four stage-one pages. */
.photo-hero{background:#06223b;max-width:1480px;margin-inline:auto}
.photo-hero .hero-scene{position:absolute;top:0;left:0;width:100%;height:auto;display:block;mask-image:linear-gradient(to bottom,#000 76%,transparent 100%)}
.photo-hero .hero-shade{position:absolute;inset:0;background:linear-gradient(90deg,rgba(6,34,59,.95) 0%,rgba(6,34,59,.86) 28%,rgba(6,34,59,.4) 48%,transparent 70%),linear-gradient(0deg,#06223b 0%,#06223b 38%,transparent 65%)}
.photo-hero .wrap{position:relative;z-index:1;padding-block:25px 24px}
.photo-hero .eyebrow{margin-bottom:12px;font-size:10px;max-width:540px}
.photo-hero h1{font-size:36px;line-height:1.07;max-width:590px;margin-bottom:18px}
.photo-hero .lead{max-width:560px;font-size:15px;line-height:1.6}
.photo-hero .hero-foot{margin-top:20px;padding-top:18px;gap:22px}
.photo-hero .hero-foot .links{margin-left:auto}
.section> .wrap>p{max-width:960px}
.technical-list dd{max-width:800px}
.band{padding-block:44px}
.note{border-radius:0 6px 6px 0}
.table-scroll{background:#fff;box-shadow:0 3px 16px rgba(7,29,73,.025)}
thead th{background:#e7f1f8;letter-spacing:.025em}
tbody tr:nth-child(even){background:#f8fbfd}
.figure{background:linear-gradient(135deg,#f4f9fc,#edf5fa);border-color:#d3e2ed}
.article-hero{background:linear-gradient(115deg,#eaf3f9,#f6f9fc)}
.article-hero .wrap{padding-block:38px 28px;border-left:3px solid #087ff5;padding-left:28px}
.article-hero h1{font-size:46px;max-width:900px;line-height:1.08}
.article-hero .lead{max-width:720px;font-size:17px}
.article-layout{grid-template-columns:215px minmax(0,760px);gap:65px}
.article p{font-size:16px;line-height:1.8}
.toc a:hover{background:#f3f8fc}
@media(max-width:700px){.photo-hero h1{font-size:32px}.photo-hero .hero-foot .links{margin-left:0}.article-layout{grid-template-columns:minmax(0,1fr)}.article-hero h1{font-size:34px}.article-hero .wrap{padding-left:18px}}