/* 2026 ammonia loop: soda white, hazard yellow, steam gray */
:root{
  --soda:#f4f7fb;
  --nh3:#e0b429;
  --steam:#8a93a0;
  --ink:#1c2430;
  --mute:#5c6570;
  --sans:"Noto Sans SC","PingFang SC",sans-serif;
  --mono:"IBM Plex Mono",ui-monospace,monospace;
}
*{box-sizing:border-box}
html{scroll-behavior:smooth}
section[id]{scroll-margin-top:64px}
body{margin:0;background:#e8edf2;color:var(--ink);font-family:var(--sans);line-height:1.7}
img{max-width:100%;display:block}
a{color:inherit;text-decoration:none}
button{font-family:inherit;cursor:pointer}
code{font-family:var(--mono);color:#8a6a10}
.skip{position:absolute;left:-999px}
.skip:focus{left:8px;top:8px;background:var(--nh3);padding:8px;z-index:40}
.nh3{position:sticky;top:0;z-index:30;display:flex;justify-content:space-between;align-items:center;padding:10px 20px;background:#2a2410;color:var(--nh3);border-bottom:6px solid var(--nh3)}
.nm small{display:block;font-family:var(--mono);font-size:11px;font-weight:400;color:#e8d48a}
#nav{display:flex;flex-wrap:wrap;gap:8px 14px;align-items:center}
#nav a{font-size:13px;color:#e8d48a}
#nav a.on{color:#fff}
.go{background:var(--nh3)!important;color:#2a2410!important;padding:6px 12px;font-weight:700}
.menu{display:none;background:transparent;color:var(--nh3);border:1px solid var(--nh3);padding:6px 10px}
.solvay>img{width:100%;height:min(52vh,480px);object-fit:cover}
.loop{width:min(860px,calc(100% - 32px));margin:20px auto 0;background:var(--soda);padding:24px 28px;box-shadow:0 0 0 1px #d0d6de}
.sankey{width:220px;height:80px;display:block}
.k{font-family:var(--mono);font-size:12px;letter-spacing:.14em;color:#8a6a10;margin:0 0 8px}
h1,h2,h3{margin:0 0 10px;line-height:1.2}
h1{font-size:clamp(1.6rem,3.8vw,2.6rem)}
.bal{margin:16px 0;padding:12px;background:#fff8d8;border-left:8px solid var(--nh3)}
.bal p{margin:4px 0 0;color:var(--mute);font-size:14px}
.acts{display:flex;flex-wrap:wrap;gap:8px}
.btn{display:inline-flex;align-items:center;padding:9px 14px;background:#2a2410;color:var(--nh3);border:0;font-weight:700;font-size:14px}
.btn.ghost{background:transparent;color:var(--ink);border:1px solid #2a2410;font-weight:400}
.w{width:min(1040px,calc(100% - 32px));margin:0 auto;padding:64px 0}
.steam{background:#d7dee6}
.tri,.g2,.cycle{display:grid;gap:14px;margin-top:16px}
.tri{grid-template-columns:repeat(3,1fr)}
.g2{grid-template-columns:1fr 1fr}
.cycle{grid-template-columns:repeat(4,1fr)}
.tri article,.g2 article,.cycle article{background:var(--soda);padding:16px}
.hot{outline:3px solid var(--nh3)}
ul{margin:0;padding-left:1.1em}
figure{margin:28px 0 0}
figcaption{font-size:13px;color:var(--mute);margin-top:8px}
footer{background:#2a2410;color:var(--nh3)}
.end{display:flex;justify-content:space-between;align-items:center;gap:12px;padding:22px 0}
@media(max-width:900px){
  .menu{display:block}
  #nav{display:none;position:absolute;top:52px;left:10px;right:10px;flex-direction:column;background:#2a2410;padding:10px}
  #nav.open{display:flex}
  .tri,.g2,.cycle{grid-template-columns:1fr}
  .end{flex-direction:column;align-items:flex-start}
}
body::after{content:"";pointer-events:none;position:fixed;inset:0;z-index:4;opacity:.08;background-image:url("images/texture.webp");background-size:320px auto;mix-blend-mode:overlay}