@import url('https://fonts.googleapis.com/css2?family=DM+Sans:wght@400;500;600;700&family=Space+Grotesk:wght@400;500;600;700&display=swap');
:root{--ink:#091317;--panel:#101e23;--ice:#d8f7ff;--blue:#00b8f0;--deep:#006987;--mist:#a9bec5;--line:#294047;--river-progress:0;--page-progress:0}
*{box-sizing:border-box}
html{scroll-behavior:smooth;scroll-padding-top:90px}
body{margin:0;background:var(--ink);color:#f4f8f9;font:18px/1.65 'DM Sans',Arial,sans-serif;overflow-x:hidden}
a{color:inherit;text-underline-offset:5px}a:hover{color:var(--blue)}a:focus-visible,button:focus-visible{outline:3px solid var(--blue);outline-offset:5px}
h1,h2,h3,strong,b{font-family:'Space Grotesk',Arial,sans-serif}h1,h2,h3,p{margin-top:0}
h2{font-size:clamp(2.5rem,5vw,5rem);font-weight:500;line-height:1.03;letter-spacing:-.055em;margin-bottom:32px}
h3{line-height:1.2}.eyebrow{font-size:11px;letter-spacing:.18em;font-weight:700;color:#7eddf8;margin-bottom:24px}
.skip{position:absolute;left:20px;top:-100px;background:#fff;color:#000;padding:10px 16px;z-index:1000}.skip:focus{top:12px}
.progress{position:fixed;z-index:999;left:0;top:0;height:3px;width:0;background:var(--blue)}
header{height:92px;display:flex;align-items:center;justify-content:space-between;padding:8px 5%;background:#fff;color:var(--ink);position:relative;z-index:100}
header img{height:72px;width:115px;object-fit:contain}.edition{font-size:11px;letter-spacing:.17em;font-weight:700}
.header-actions{display:flex;align-items:center;gap:30px}.language{display:flex;border:1px solid #cad4d7;border-radius:30px;padding:3px}
.language button{border:0;background:transparent;color:#526167;border-radius:22px;padding:7px 11px;font:700 11px 'DM Sans';cursor:pointer}
.language button[aria-pressed=true]{background:var(--ink);color:#fff}.press-nav{text-decoration:none;font-size:13px}.press-nav span{margin-left:12px}
.hero{height:calc(100svh - 92px);min-height:680px;position:relative;display:flex;align-items:center;isolation:isolate;overflow:hidden}
.hero-photo{position:absolute;inset:-12% 0;z-index:-3;background:#20343d url('everest.jpg') 58% center/cover no-repeat;will-change:transform}
.hero-glow{position:absolute;z-index:-2;width:60vw;height:60vw;border-radius:50%;right:-22vw;bottom:-32vw;background:radial-gradient(circle,rgba(0,184,240,.28),transparent 68%);will-change:transform}
.hero:after{content:'';position:absolute;inset:0;z-index:-1;background:linear-gradient(90deg,rgba(4,13,17,.94) 5%,rgba(4,13,17,.54) 58%,rgba(4,13,17,.18)),linear-gradient(0deg,var(--ink),transparent 45%)}
.hero-inner{padding:70px 8% 130px;max-width:1120px}.hero .eyebrow{color:#c2f4ff}
h1{font-size:clamp(5rem,12vw,12rem);line-height:.82;letter-spacing:-.075em;font-weight:500;margin:0 0 42px}h1 em{font-style:normal;color:var(--ice)}
.intro{font-size:clamp(1.15rem,2vw,1.55rem);max-width:660px;color:#d0e0e5;line-height:1.5}
.start{display:inline-flex;align-items:center;gap:28px;text-decoration:none;font-size:13px;margin-top:16px}.start span{width:46px;height:46px;border:1px solid #6d8a94;border-radius:50%;display:grid;place-items:center;font-size:20px}
.hero-meta{position:absolute;bottom:25px;left:5%;right:5%;display:flex;justify-content:space-between;font-size:10px;letter-spacing:.18em;color:#9bb2ba}
.river-story{position:relative;max-width:1480px;margin:auto;padding:60px 0 100px;isolation:isolate}
.river-bed{position:absolute;z-index:-1;left:50%;top:0;bottom:0;width:min(29vw,340px);transform:translateX(-50%);opacity:.95;filter:drop-shadow(0 0 28px rgba(0,184,240,.15))}
.river-bed svg{width:100%;height:100%;overflow:visible}.river-shadow{fill:none;stroke:#152c35;stroke-width:114;stroke-linecap:round}
.river-water{fill:none;stroke:#20c3ef;stroke-width:44;stroke-linecap:round;stroke-dasharray:1;stroke-dashoffset:calc(1 - var(--river-progress));opacity:.78}
.chapter{min-height:90vh;position:relative;display:grid;grid-template-columns:1fr 1fr;align-items:center;padding:110px 8%;gap:14%;border-bottom:1px solid rgba(89,122,133,.18)}
.chapter:nth-of-type(even) .chapter-card{grid-column:2}.chapter:nth-of-type(odd) .chapter-card{grid-column:1}.chapter.opening{padding-top:50px}
.chapter-card{max-width:650px;background:rgba(9,19,23,.82);backdrop-filter:blur(12px);border:1px solid rgba(121,181,200,.18);padding:clamp(28px,4.5vw,62px);box-shadow:0 28px 70px rgba(0,0,0,.22)}
.lead{font-size:clamp(1.12rem,1.7vw,1.4rem);line-height:1.6;color:#c1d2d8}.source-link{display:inline-block;margin-top:18px;font-size:13px;color:#bbdce5}
.river-marker{position:absolute;left:50%;top:50%;transform:translate(-50%,-50%);width:118px;height:118px;border-radius:50%;background:#dff9ff;color:#09202a;display:flex;flex-direction:column;align-items:center;justify-content:center;text-align:center;box-shadow:0 0 0 12px rgba(9,19,23,.82),0 0 55px rgba(0,184,240,.35);z-index:2}
.river-marker span{font:600 25px 'Space Grotesk'}.river-marker small{font-size:7px;line-height:1.35;letter-spacing:.08em;max-width:88px;text-transform:uppercase;margin-top:3px}
.rewind{position:absolute;left:50%;bottom:55px;transform:translateX(-50%);width:min(420px,80vw);text-align:center;font:500 17px/1.5 'Space Grotesk';color:#a8e7f7;background:var(--ink);padding:14px}
.stat-pair,.result-grid{display:grid;grid-template-columns:1fr 1fr;gap:28px;margin:40px 0;padding:28px 0;border-top:1px solid var(--line);border-bottom:1px solid var(--line)}
.stat-pair strong,.result-grid strong{display:block;color:var(--ice);font-size:clamp(2.2rem,4vw,4rem);line-height:1;letter-spacing:-.06em;font-weight:500}
.stat-pair span,.result-grid span,.single-stat span,.science-total span{display:block;color:var(--mist);font-size:13px;line-height:1.45;margin-top:12px}
aside{border-left:2px solid var(--blue);padding:5px 0 5px 22px;color:#9fb5bd;font-size:14px;margin:30px 0}aside h3{color:#dff8ff;font-size:19px;margin-bottom:10px}aside p{margin-bottom:0}
.flow-strip{display:grid;grid-template-columns:repeat(3,1fr);margin-top:42px}.flow-strip>div{padding:20px 20px 20px 0;border-top:2px solid var(--blue);position:relative}.flow-strip>div:after{content:'→';position:absolute;right:7px;top:17px;color:#4f8494}.flow-strip>div:last-child:after{display:none}
.flow-strip b{font-size:10px;color:#56cbed}.flow-strip strong,.flow-strip span{display:block}.flow-strip strong{font-size:15px;margin:18px 0 5px}.flow-strip span{font-size:12px;color:#9eb3ba}
.single-stat{margin-top:35px;padding:30px 0;border-top:1px solid var(--line)}.single-stat strong{font-size:clamp(3rem,6vw,5rem);color:var(--ice);font-weight:500;letter-spacing:-.06em}
.fuel-chapter .river-water{filter:hue-rotate(20deg)}.waste-chapter{background:radial-gradient(circle at 50% 50%,rgba(0,126,165,.08),transparent 42%)}
.equation{display:flex;align-items:center;justify-content:space-between;gap:12px;margin:38px 0}.equation span{flex:1}.equation b{display:block;font-size:clamp(1.8rem,3vw,3rem);font-weight:500}.equation small{font-size:11px;color:#9bb1b8}.equation i{font-style:normal;color:#56808d}
.science-chapter{min-height:125vh}.science-chapter .chapter-card{max-width:720px}.science-total{padding:30px 0;margin-top:36px;border-top:1px solid var(--line)}
.science-total strong{display:block;font-size:clamp(3.5rem,7vw,6.5rem);font-weight:500;letter-spacing:-.07em;color:var(--ice)}
.thermal{height:30px;display:flex;background:#18333d;margin-top:20px}.thermal-fuels{width:93.82%;background:#c6f2ff}.thermal-urine{width:6.18%;background:#00a8dc}
.thermal-key{display:flex;justify-content:space-between;font-size:12px;color:#9bb4bd;margin-top:10px}
.six-callout{display:grid;grid-template-columns:auto 1fr;gap:28px;align-items:center;margin:48px -20px 30px;padding:30px 20px;background:#d9f8ff;color:#0c1b20}
.six-callout>span{font:600 clamp(3rem,6vw,5.6rem)/1 'Space Grotesk';letter-spacing:-.07em}.six-callout h3{font-size:22px;margin-bottom:8px}.six-callout p{font-size:14px;margin:0;color:#344c55}
.citation-note{font-size:13px;color:#9bb2ba}.action-chapter{min-height:105vh}.action-chapter .chapter-card{max-width:760px;background:rgba(11,36,45,.9)}
.action-grid{display:grid;grid-template-columns:repeat(3,1fr);gap:18px;margin-top:50px}.action-grid article{border-top:2px solid var(--blue);padding-top:20px}.action-grid b{font-size:11px;color:#61cbe9}.action-grid h3{font-size:19px;margin:13px 0}.action-grid p{font-size:13px;color:#a9c0c8}
blockquote{font:500 clamp(1.45rem,2.5vw,2.3rem)/1.35 'Space Grotesk';margin:55px 0 0;padding:0;color:#dbf7ff}blockquote strong{color:#5ed7f7}
.archive{background:#eef6f8;color:#0b1a1f;padding:120px 8%}.archive-head{max-width:820px;margin-bottom:80px}.archive .eyebrow{color:#007fa7}.archive .lead{color:#496069}
.press-group{display:grid;grid-template-columns:230px 1fr;gap:55px;padding:35px 0;border-top:1px solid #b9cdd3}.press-year strong{display:block;font-size:clamp(3rem,5vw,5rem);font-weight:500;line-height:1;letter-spacing:-.07em}.press-year span{display:block;font-size:12px;color:#587079;margin-top:10px}
.press-items{display:grid;grid-template-columns:1fr 1fr;gap:0 30px}.press-item{display:flex;justify-content:space-between;gap:15px;text-decoration:none;padding:17px 0;border-bottom:1px solid #cad9dd}.press-item b{display:block;font-size:15px}.press-item small{display:block;font-size:11px;color:#61767d;margin-top:4px}.press-item i{font-style:normal;color:#108eb4}
.archive-note{font-size:12px;color:#667c84;max-width:800px;margin-top:50px}
.sources{padding:100px 8%;max-width:1450px;margin:auto}.source-grid{display:grid;grid-template-columns:1fr 1fr;gap:20px}
.source-grid a{display:grid;grid-template-columns:110px 1fr;gap:20px;padding:25px 0;border-top:1px solid var(--line);text-decoration:none}.source-grid b{color:#82dff7;font-size:13px}.source-grid span{font-size:14px;color:#a9bec5}
footer{background:#fff;color:#101719;padding:70px 8%;display:grid;grid-template-columns:180px 2fr;gap:30px 60px;align-items:start}footer img{width:160px}footer h2{font-size:clamp(2rem,4vw,4rem);margin:0}footer a{font-size:13px}footer>span{font-size:10px;letter-spacing:.15em;align-self:center}
.reveal,.press-group{transition:opacity .8s ease,transform .9s cubic-bezier(.2,.7,.2,1)}.js .reveal:not(.visible),.js .press-group:not(.visible){opacity:.08;transform:translateY(45px)}
@media(max-width:900px){
  .edition{display:none}.chapter{grid-template-columns:1fr;padding:110px 7% 110px 15%;min-height:auto}.chapter:nth-of-type(n) .chapter-card{grid-column:1}.river-bed{left:7%;width:90px;transform:none}.river-shadow{stroke-width:70}.river-water{stroke-width:24}.river-marker{left:7%;width:72px;height:72px}.river-marker span{font-size:17px}.river-marker small{display:none}.chapter-card{max-width:none}.rewind{position:relative;left:auto;bottom:auto;transform:none;margin:60px auto -20px}.press-group{grid-template-columns:1fr;gap:18px}.action-grid{grid-template-columns:1fr}.source-grid{grid-template-columns:1fr}
}
@media(max-width:650px){
  body{font-size:16px}header{height:78px;padding:6px 5%}header img{height:62px;width:96px}.header-actions{gap:12px}.press-nav{display:none}.language button{padding:6px 9px}
  .hero{height:calc(100svh - 78px);min-height:630px}.hero-inner{padding:60px 7% 110px}h1{font-size:clamp(4.2rem,22vw,7rem)}.hero-meta span:last-child{display:none}
  .chapter{padding:90px 6% 90px 18%}.river-bed{left:3%;width:74px}.river-marker{left:6%;width:56px;height:56px}.river-marker span{font-size:13px}.chapter-card{padding:26px 22px}.stat-pair,.result-grid{gap:15px}.stat-pair strong,.result-grid strong{font-size:2rem}
  .flow-strip{grid-template-columns:1fr}.flow-strip>div:after{content:'↓';top:auto;bottom:-11px;right:12px}.flow-strip>div:last-child:after{display:none}.six-callout{grid-template-columns:1fr;gap:12px}.equation{gap:6px}.equation small{font-size:9px}.thermal-key{flex-direction:column;gap:4px}
  .archive{padding:80px 7%}.press-items{grid-template-columns:1fr}.source-grid a{grid-template-columns:75px 1fr}.sources{padding:75px 7%}footer{grid-template-columns:1fr;padding:50px 7%}footer img{width:130px}
}
@media(prefers-reduced-motion:reduce){html{scroll-behavior:auto}.hero-photo,.hero-glow{transform:none!important}.reveal,.press-group{transition:none}.js .reveal:not(.visible),.js .press-group:not(.visible){opacity:1;transform:none}.river-water{stroke-dashoffset:0}}