:root{
  color-scheme:light;
  --bg:#F4F3EF; --surface:#FFFFFF; --surface-2:#EAE8E1;
  --ink:#1A1C1A; --ink-2:#4F554F; --ink-3:#6C726B;
  --line:rgba(26,28,26,.10); --line-strong:rgba(26,28,26,.22);
  --accent:#2F6B4F; --accent-ink:#FFFFFF; --accent-soft:rgba(47,107,79,.10);
  --glass:rgba(255,255,255,.58); --glass-strong:rgba(255,255,255,.76);
  --glass-edge:rgba(255,255,255,.75); --glass-line:rgba(26,28,26,.08);
  --glass-shadow:0 1px 1px rgba(26,28,26,.04),0 10px 30px -8px rgba(26,28,26,.18);
  --amb-1:rgba(150,190,160,.42); --amb-2:rgba(214,190,150,.38); --amb-3:rgba(150,175,205,.26);
  --r-sm:10px; --r-md:16px; --r-lg:24px; --r-pill:999px;
  --ease:cubic-bezier(.2,.8,.2,1);
}
@media (prefers-color-scheme:dark){:root:not([data-theme="light"]){
  color-scheme:dark;
  --bg:#101210; --surface:#181A18; --surface-2:#1F221F;
  --ink:#E9EAE6; --ink-2:#AFB4AD; --ink-3:#8C918A;
  --line:rgba(233,234,230,.10); --line-strong:rgba(233,234,230,.22);
  --accent:#86C9A3; --accent-ink:#0B1710; --accent-soft:rgba(134,201,163,.12);
  --glass:rgba(26,30,27,.52); --glass-strong:rgba(26,30,27,.72);
  --glass-edge:rgba(255,255,255,.14); --glass-line:rgba(255,255,255,.08);
  --glass-shadow:0 1px 1px rgba(0,0,0,.3),0 14px 40px -10px rgba(0,0,0,.6);
  --amb-1:rgba(50,120,85,.22); --amb-2:rgba(150,110,60,.20); --amb-3:rgba(60,90,140,.18);
}}
:root[data-theme="dark"]{
  color-scheme:dark;
  --bg:#101210; --surface:#181A18; --surface-2:#1F221F;
  --ink:#E9EAE6; --ink-2:#AFB4AD; --ink-3:#8C918A;
  --line:rgba(233,234,230,.10); --line-strong:rgba(233,234,230,.22);
  --accent:#86C9A3; --accent-ink:#0B1710; --accent-soft:rgba(134,201,163,.12);
  --glass:rgba(26,30,27,.52); --glass-strong:rgba(26,30,27,.72);
  --glass-edge:rgba(255,255,255,.14); --glass-line:rgba(255,255,255,.08);
  --glass-shadow:0 1px 1px rgba(0,0,0,.3),0 14px 40px -10px rgba(0,0,0,.6);
  --amb-1:rgba(50,120,85,.22); --amb-2:rgba(150,110,60,.20); --amb-3:rgba(60,90,140,.18);
}
*{box-sizing:border-box}
html{-webkit-text-size-adjust:100%;scroll-padding-top:96px}
body{margin:0;background:var(--bg);color:var(--ink);font-family:"Instrument Sans",system-ui,-apple-system,"Segoe UI",sans-serif;
  font-size:16px;line-height:1.6;overflow-x:hidden;transition:background-color .3s var(--ease),color .3s var(--ease)}
body::before{content:"";position:fixed;inset:-20vmax;z-index:-1;pointer-events:none;
  background:radial-gradient(40vmax 30vmax at 10% 6%,var(--amb-1),transparent 70%),
             radial-gradient(38vmax 30vmax at 92% 20%,var(--amb-2),transparent 70%),
             radial-gradient(40vmax 34vmax at 55% 100%,var(--amb-3),transparent 70%)}
img{max-width:100%;display:block}
a{color:var(--accent);text-decoration:underline;text-decoration-thickness:1px;text-underline-offset:3px}
a:hover{text-decoration-thickness:2px}
:focus-visible{outline:2px solid var(--accent);outline-offset:3px;border-radius:6px}
.wrap{max-width:1180px;margin-inline:auto;padding-inline:clamp(16px,4vw,32px)}
.mono{font-family:"IBM Plex Mono",ui-monospace,Menlo,Consolas,monospace;font-size:12.5px;line-height:1.5}
h1,h2,h3{font-family:"Newsreader",Georgia,serif;font-weight:500;line-height:1.12;margin:0;letter-spacing:-.01em;text-wrap:balance}
h1{font-size:clamp(2.2rem,5.2vw,3.7rem)}
h2{font-size:clamp(1.5rem,2.8vw,2rem);margin-bottom:12px}
h3{font-size:1.2rem}
p{margin:0 0 1em}
.muted{color:var(--ink-2)}
.skip{position:absolute;left:-9999px}
.skip:focus{left:12px;top:12px;background:var(--ink);color:var(--bg);padding:10px 14px;border-radius:8px;z-index:100}

.glass{position:relative;background:var(--glass);border:1px solid var(--glass-line);box-shadow:var(--glass-shadow),inset 0 1px 0 var(--glass-edge);
  -webkit-backdrop-filter:blur(22px) saturate(170%);backdrop-filter:blur(22px) saturate(170%)}
.glass::after{content:"";position:absolute;inset:0;border-radius:inherit;pointer-events:none;
  background:linear-gradient(160deg,rgba(255,255,255,.22),rgba(255,255,255,0) 38%)}
:root[data-theme="dark"] .glass::after{background:linear-gradient(160deg,rgba(255,255,255,.07),rgba(255,255,255,0) 38%)}
@media (prefers-color-scheme:dark){:root:not([data-theme="light"]) .glass::after{background:linear-gradient(160deg,rgba(255,255,255,.07),rgba(255,255,255,0) 38%)}}
.glass--strong{background:var(--glass-strong)}
@supports not ((backdrop-filter:blur(1px)) or (-webkit-backdrop-filter:blur(1px))){.glass{background:var(--glass-strong)}}
@media (prefers-reduced-transparency:reduce){.glass{background:var(--surface);-webkit-backdrop-filter:none;backdrop-filter:none}}

.nav-shell{position:sticky;top:12px;z-index:50;padding-inline:clamp(10px,3vw,24px);margin-top:12px}
.navbar{max-width:1180px;margin-inline:auto;border-radius:var(--r-pill);display:flex;align-items:center;gap:8px;padding:6px 6px 6px 20px}
.logo{font-family:"Newsreader",Georgia,serif;font-weight:600;font-size:1.3rem;color:var(--ink);text-decoration:none;margin-right:auto;white-space:nowrap}
.logo:hover{text-decoration:none}
.nav{display:flex;gap:2px}
.nav a{display:inline-flex;align-items:center;min-height:44px;padding:0 14px;border-radius:var(--r-pill);color:var(--ink-2);text-decoration:none;font-size:.95rem;font-weight:500;transition:background-color .2s var(--ease),color .2s}
.nav a:hover{color:var(--ink);background:var(--accent-soft)}
.nav a[aria-current]{color:var(--ink);background:var(--glass-strong);box-shadow:inset 0 0 0 1px var(--glass-line)}
.theme-btn{display:grid;place-items:center;width:44px;height:44px;border-radius:50%;border:0;background:transparent;color:var(--ink);cursor:pointer;transition:background-color .2s}
.theme-btn:hover{background:var(--accent-soft)}
.theme-btn svg{width:20px;height:20px}
.theme-btn .i-sun{display:none}
:root[data-theme="dark"] .theme-btn .i-sun{display:block}
:root[data-theme="dark"] .theme-btn .i-moon{display:none}
@media (prefers-color-scheme:dark){:root:not([data-theme="light"]) .theme-btn .i-sun{display:block}:root:not([data-theme="light"]) .theme-btn .i-moon{display:none}}
@media (max-width:640px){
  .navbar{flex-wrap:wrap;border-radius:var(--r-lg);padding:6px 6px 6px 16px}
  .nav{order:3;width:100%;justify-content:space-between;margin:2px -2px 0}
  .nav a{padding:0 10px;font-size:.9rem}
}

main{padding-block:28px 72px}
.stage{position:relative;border-radius:var(--r-lg);overflow:hidden;min-height:clamp(400px,58vh,560px);display:flex;align-items:flex-end;background:#15170f;isolation:isolate}
.stage>img{position:absolute;inset:0;width:100%;height:100%;object-fit:cover;z-index:-1}
.stage--short{min-height:clamp(280px,38vh,400px)}
.stage__panel{margin:clamp(12px,2.4vw,24px);padding:clamp(20px,3vw,32px);border-radius:var(--r-lg);max-width:660px;width:100%}
.stage__cap{position:absolute;right:14px;top:14px;border-radius:var(--r-pill);padding:6px 12px;color:var(--ink-2)}
.stage__cap a{color:inherit}
.lede{font-size:clamp(1.05rem,1.6vw,1.2rem);color:var(--ink-2);max-width:40em;margin:12px 0 0}
.crumbs{margin:0 0 12px;color:var(--ink-3)}
.crumbs a{color:var(--ink-2)}
.btn{display:inline-flex;align-items:center;justify-content:center;gap:8px;min-height:44px;padding:0 20px;border-radius:var(--r-pill);border:0;
  background:var(--ink);color:var(--bg);font:inherit;font-weight:600;font-size:.95rem;text-decoration:none;cursor:pointer;transition:transform .15s var(--ease),opacity .15s}
.btn:hover{text-decoration:none;opacity:.9}
.btn:active{transform:scale(.97)}
.btn--quiet{background:var(--accent-soft);color:var(--ink)}
.cta-row{display:flex;gap:10px;flex-wrap:wrap;margin-top:22px}

section{margin-top:clamp(52px,7vw,88px)}
.sec-head{display:flex;justify-content:space-between;align-items:flex-end;gap:16px;flex-wrap:wrap;margin-bottom:22px}
.sec-head p{margin:0;max-width:40em}
.cards{display:grid;gap:16px;grid-template-columns:repeat(auto-fill,minmax(270px,1fr))}
.card{display:flex;flex-direction:column;border-radius:var(--r-lg);overflow:hidden;text-decoration:none;color:var(--ink);transition:transform .2s var(--ease)}
.card:hover{text-decoration:none;transform:translateY(-2px)}
.card img{aspect-ratio:16/10;object-fit:cover;width:100%}
.card__b{padding:18px 20px 22px}
.card__b b{display:block;font-family:"Newsreader",Georgia,serif;font-weight:500;font-size:1.3rem;line-height:1.15}
.card__b span{display:block;margin-top:6px;color:var(--ink-2);font-size:.94rem}
.card__b em{font-style:normal;font-family:"IBM Plex Mono",monospace;font-size:11.5px;color:var(--accent);text-transform:uppercase;letter-spacing:.08em}

/* calculator */
.calc{display:grid;gap:24px;margin-top:28px;align-items:start}
@media (min-width:900px){.calc{grid-template-columns:minmax(0,420px) minmax(0,1fr);gap:40px}}
.form{border-radius:var(--r-lg);padding:22px}
@media (min-width:900px){.form{position:sticky;top:100px}}
.field{margin-bottom:18px}
.field:last-child{margin-bottom:0}
.field label{display:block;font-weight:600;font-size:.92rem;margin-bottom:6px}
.field .hint{display:block;font-weight:400;color:var(--ink-3);font-size:.85rem;margin-top:2px}
.field input,.field select{width:100%;min-height:44px;padding:0 12px;border-radius:var(--r-sm);border:1px solid var(--line-strong);background:var(--surface);color:var(--ink);font:inherit;font-size:1rem}
.field input:focus,.field select:focus{outline:2px solid var(--accent);outline-offset:1px}
.out{border-radius:var(--r-lg);padding:22px 24px}
.out h2{margin-top:0}
.rows{list-style:none;margin:0;padding:0}
.rows li{display:flex;justify-content:space-between;gap:16px;padding:12px 0;border-top:1px solid var(--line)}
.rows li:first-child{border-top:0}
.rows b{font-family:"Newsreader",Georgia,serif;font-weight:500;font-size:1.25rem;font-variant-numeric:tabular-nums;white-space:nowrap}
.rows span small{display:block;color:var(--ink-3);font-size:.84rem;margin-top:2px}
.assume{margin-top:22px;padding-top:16px;border-top:1px solid var(--line);color:var(--ink-3);font-size:.9rem}
.assume ul{margin:8px 0 0;padding-left:1.1em}
.big{display:grid;gap:12px;grid-template-columns:repeat(auto-fit,minmax(150px,1fr));margin-bottom:20px}
.big div{border-radius:var(--r-md);padding:14px 16px;background:var(--accent-soft)}
.big b{display:block;font-family:"Newsreader",Georgia,serif;font-size:1.9rem;font-weight:500;line-height:1.1;font-variant-numeric:tabular-nums}
.big span{display:block;font-size:.85rem;color:var(--ink-2);margin-top:2px}

/* article */
.entry{display:grid;gap:28px;margin-top:28px;align-items:start}
@media (min-width:920px){.entry{grid-template-columns:minmax(0,1fr) 300px;gap:48px}}
.prose{font-family:"Newsreader",Georgia,serif;font-size:1.2rem;line-height:1.65}
.prose p{max-width:34em}
.prose h2{margin-top:38px;font-size:1.5rem}
.prose ul{margin:0 0 1em;padding-left:1.1em}
.toc{border-radius:var(--r-lg);padding:18px 20px;font-size:.95rem}
@media (min-width:920px){.toc{position:sticky;top:100px}}
.toc p{font-family:"IBM Plex Mono",monospace;font-size:11.5px;text-transform:uppercase;letter-spacing:.08em;color:var(--ink-3);margin:0 0 10px}
.toc ol{margin:0;padding:0;list-style:none;counter-reset:t}
.toc li{counter-increment:t;border-top:1px solid var(--line)}
.toc li:first-child{border-top:0}
.toc a{display:block;padding:9px 0;color:var(--ink);text-decoration:none}
.toc a:hover{color:var(--accent)}
.toc a::before{content:counter(t) ". ";color:var(--ink-3)}
.revised{margin-top:36px;padding-top:14px;border-top:1px solid var(--line);color:var(--ink-3);font-family:"IBM Plex Mono",monospace;font-size:12.5px}
.notice{border-radius:var(--r-lg);padding:20px 22px;margin-top:26px;max-width:42em;font-family:"Instrument Sans",sans-serif;font-size:1rem}
.notice h2{font-size:1.3rem}
.credits{list-style:none;padding:0;margin:0;columns:2 250px;column-gap:28px;font-family:"Instrument Sans",sans-serif;font-size:.9rem;color:var(--ink-2)}
.credits li{break-inside:avoid;padding:3px 0}

.foot{margin-top:24px;padding:0 clamp(10px,3vw,24px) 24px}
.foot__in{max-width:1180px;margin-inline:auto;border-radius:var(--r-lg);padding:22px 26px;display:grid;gap:14px;color:var(--ink-2);font-size:.92rem}
.foot__row{display:flex;justify-content:space-between;align-items:center;gap:16px;flex-wrap:wrap}
.foot nav{display:flex;flex-wrap:wrap;gap:4px}
.foot nav a{display:inline-flex;align-items:center;min-height:44px;padding:0 10px;color:var(--ink-2);text-decoration:none;border-radius:var(--r-pill)}
.foot nav a:hover{color:var(--ink);background:var(--accent-soft)}
.foot .dis{margin:0;font-size:.84rem;color:var(--ink-3);max-width:62em}
@media (prefers-reduced-motion:reduce){*,*::before,*::after{transition:none!important;animation:none!important}}