*{box-sizing:border-box}html{scroll-behavior:smooth}:root{--bg:#06141d;--panel:#0c2633;--text:#f5faf9;--muted:#b7ccd2;--green:#8dca57;--blue:#66c8e8;--line:rgba(255,255,255,.14)}body{margin:0;background:linear-gradient(#06141d,#082331 55%,#06141d);color:var(--text);font-family:Arial,Helvetica,sans-serif;line-height:1.55}.shell{width:min(1220px,calc(100% - 32px));margin:auto}header{position:sticky;top:0;z-index:20;background:rgba(4,18,26,.92);backdrop-filter:blur(12px);border-bottom:1px solid var(--line)}.nav{min-height:70px;display:flex;justify-content:space-between;align-items:center;gap:20px}.brand{color:#fff;text-decoration:none;font-weight:900;letter-spacing:.08em}.brand b{color:var(--green)}nav{display:flex;gap:18px;flex-wrap:wrap}nav a{color:var(--muted);text-decoration:none}.active,nav a:hover{color:#fff}.hero{padding:70px 0 40px}.eyebrow{text-transform:uppercase;letter-spacing:.14em;color:var(--green);font-size:.78rem;font-weight:900}h1{font-size:clamp(3rem,7vw,6rem);line-height:.95;margin:.15em 0}.lead{max-width:900px;color:var(--muted);font-size:1.2rem}.hero-image,.science-card{margin:28px 0 0;background:var(--panel);border:1px solid var(--line);border-radius:22px;overflow:hidden}.expand{width:100%;padding:0;border:0;background:#000;cursor:zoom-in}.expand img{display:block;width:100%;height:auto}.hero-image figcaption,.science-card figcaption{padding:20px}.hero-image h2,.science-card h3{margin:0 0 7px}.hero-image p,.science-card p{margin:0;color:var(--muted)}.feature{margin:35px 0 65px;padding:34px;border:1px solid var(--line);border-radius:24px;background:linear-gradient(135deg,rgba(102,200,232,.11),rgba(141,202,87,.09))}.feature h2,.section-head h2,.roadmap h2{font-size:clamp(2rem,4vw,3.5rem);margin:.1em 0}.process{display:flex;align-items:center;gap:10px;flex-wrap:wrap;margin-top:24px}.process span{padding:13px 16px;background:var(--panel);border:1px solid var(--line);border-radius:14px}.process b{color:var(--green)}.chapter{padding:55px 0;border-top:1px solid var(--line)}.gallery{display:grid;grid-template-columns:repeat(3,1fr);gap:20px}.science-card{margin:0}.science-card img{aspect-ratio:16/10;object-fit:cover}.science-card.missing{display:none}.roadmap{padding:65px 0 100px;border-top:1px solid var(--line)}.phases{display:grid;grid-template-columns:repeat(4,1fr);gap:16px}.phases article{background:var(--panel);border:1px solid var(--line);border-radius:18px;padding:22px}.phases b{font-size:2rem;color:var(--blue)}.phases p{color:var(--muted)}#lightbox{position:fixed;inset:0;z-index:100;background:rgba(0,0,0,.94);display:grid;place-items:center;padding:30px}#lightbox[hidden]{display:none}#lightbox img{max-width:96vw;max-height:92vh}#close{position:absolute;top:12px;right:22px;border:0;background:none;color:#fff;font-size:3rem;cursor:pointer}@media(max-width:900px){.gallery{grid-template-columns:repeat(2,1fr)}.phases{grid-template-columns:repeat(2,1fr)}}@media(max-width:600px){.nav{align-items:flex-start;flex-direction:column;padding:15px 0}.gallery,.phases{grid-template-columns:1fr}.feature{padding:24px 18px}}
/* v4: full shared navigation + visual hydrogen chapter */
header .nav{min-height:86px}.brand{font-size:1rem;white-space:nowrap}
header nav{align-items:center;justify-content:flex-end}
header nav a{padding:9px 8px;text-transform:uppercase;font-size:.82rem;font-weight:800;letter-spacing:.02em}
header nav .nav-cta{border:1px solid #d9a71d;border-radius:4px;padding:12px 16px;color:#fff}
.feature-gallery{display:grid;grid-template-columns:repeat(2,minmax(0,1fr));gap:16px;margin-top:26px}
.feature-image{border:1px solid var(--line);border-radius:17px;overflow:hidden;background:#06141d;padding:0;cursor:zoom-in}
.feature-image img{display:block;width:100%;aspect-ratio:16/10;object-fit:cover}
.science-card.missing{display:block}
@media(max-width:980px){header .nav{align-items:flex-start;flex-direction:column;padding:15px 0}header nav{justify-content:flex-start}.feature-gallery{grid-template-columns:1fr}}