/* Measure Twice — "paint chip" system.
   Layout: white working surface; each of the six categories owns a swatch color that runs through its
   cards, calculator result panel and page band, like a strip from a paint-chip fan. */
:root{
  --bg:#ffffff; --surface:#f3f5f7; --ink:#17202a; --muted:#5d6875; --line:#dde2e7; --focus:#2f5bd3;
  --c-plan:#2f5bd3; --c-energy:#c4441f; --c-inside:#167a7b; --c-masonry:#5a6b7c; --c-framing:#966010; --c-outside:#33783e;
  --t-plan:#2f5bd3; --t-energy:#c4441f; --t-inside:#167a7b; --t-masonry:#4d5d6d; --t-framing:#8a580e; --t-outside:#2f7039;
  --cat:var(--c-plan); --cat-text:var(--t-plan); --on-cat:#ffffff;
  --display:"Bricolage Grotesque","Avenir Next","Segoe UI",system-ui,sans-serif;
  --body:"Atkinson Hyperlegible","Segoe UI",system-ui,-apple-system,sans-serif;
  --r-lg:18px; --r-md:12px; --r-sm:8px;
  color-scheme:light;
}
@media (prefers-color-scheme:dark){:root:not([data-theme="light"]){
  --bg:#12161b; --surface:#1b2128; --ink:#e9edf1; --muted:#9ba6b2; --line:#2b333c; --focus:#8fb0ff;
  --t-plan:#8fb0ff; --t-energy:#ff9a74; --t-inside:#5cc9ca; --t-masonry:#a9b8c8; --t-framing:#e8b467; --t-outside:#7fcf8d; color-scheme:dark}}
:root[data-theme="dark"]{
  --bg:#12161b; --surface:#1b2128; --ink:#e9edf1; --muted:#9ba6b2; --line:#2b333c; --focus:#8fb0ff;
  --t-plan:#8fb0ff; --t-energy:#ff9a74; --t-inside:#5cc9ca; --t-masonry:#a9b8c8; --t-framing:#e8b467; --t-outside:#7fcf8d; color-scheme:dark}

.cat-plan{--cat:var(--c-plan);--cat-text:var(--t-plan)} .cat-energy{--cat:var(--c-energy);--cat-text:var(--t-energy)}
.cat-inside{--cat:var(--c-inside);--cat-text:var(--t-inside)} .cat-masonry{--cat:var(--c-masonry);--cat-text:var(--t-masonry)}
.cat-framing{--cat:var(--c-framing);--cat-text:var(--t-framing)} .cat-outside{--cat:var(--c-outside);--cat-text:var(--t-outside)}

*{box-sizing:border-box}
html{-webkit-text-size-adjust:100%}
body{margin:0;background:var(--bg);color:var(--ink);font-family:var(--body);font-size:18px;line-height:1.6}
a{color:var(--cat-text)}
a:focus-visible,button:focus-visible,input:focus-visible,select:focus-visible,summary:focus-visible{outline:3px solid var(--focus);outline-offset:2px;border-radius:4px}
.wrap{max-width:1140px;margin:0 auto;padding-left:max(18px,env(safe-area-inset-left,0px));padding-right:max(18px,env(safe-area-inset-right,0px))}
h1,h2,h3{font-family:var(--display);line-height:1.08;text-wrap:balance;margin:0;letter-spacing:-.015em}
h1{font-size:clamp(36px,5.4vw,60px);font-weight:750}
h2{font-size:clamp(26px,3vw,34px);font-weight:700;margin-top:44px}
h3{font-size:22px;font-weight:700;margin-top:26px}
svg.ico{width:1em;height:1em;flex:none}

/* header */
.top{border-bottom:1px solid var(--line);background:var(--bg)}
.top .wrap{display:flex;align-items:center;gap:20px;flex-wrap:wrap;padding-block:14px}
.brand{display:flex;align-items:center;gap:10px;font-family:var(--display);font-weight:800;font-size:23px;color:var(--ink);text-decoration:none;letter-spacing:-.02em}
.brand .mark{width:34px;height:34px}
.mainnav{display:flex;gap:22px;margin-left:auto}
.mainnav a{font-weight:700;font-size:16px;color:var(--ink);text-decoration:none}
.mainnav a:hover{color:var(--c-plan)}
.units{display:inline-flex;border:1px solid var(--line);border-radius:999px;padding:3px;background:var(--surface)}
.units button{font:700 14px var(--body);border:0;background:transparent;color:var(--muted);padding:7px 14px;border-radius:999px;cursor:pointer}
.units button[aria-pressed="true"]{background:var(--ink);color:var(--bg)}
@media (max-width:640px){.top .wrap{gap:10px 12px}.brand{font-size:20px}.brand .mark{width:30px;height:30px}.mainnav{order:3;width:100%;margin:0;gap:18px}.units{margin-left:auto}.units button{padding:6px 11px}}

/* home hero with swatch fan */
.hero{display:grid;grid-template-columns:minmax(0,1.1fr) minmax(0,.9fr);gap:40px;align-items:center;padding-block:48px 24px}
@media (max-width:860px){.hero{grid-template-columns:1fr;gap:28px;padding-block:32px 8px}}
.hero h1{font-size:clamp(40px,6.2vw,74px);max-width:13ch}
.hero .lede{margin-top:18px}
.lede{font-size:20px;color:var(--muted);max-width:60ch;margin:12px 0 0}
.search{margin-top:26px;max-width:540px;position:relative}
.search input{width:100%;font:400 19px var(--body);padding:16px 18px 16px 50px;border:2px solid var(--ink);border-radius:var(--r-md);background:var(--bg);color:var(--ink)}
.search svg{position:absolute;left:17px;top:50%;transform:translateY(-50%);width:22px;height:22px;color:var(--muted)}
.fan{display:flex;flex-direction:column;gap:10px}
.chip{display:flex;align-items:center;gap:14px;background:var(--cat);color:var(--on-cat);border-radius:var(--r-md);padding:14px 18px;text-decoration:none;
  transform:rotate(var(--rot,0deg));transform-origin:left center;transition:transform .25s ease}
.chip:hover{transform:rotate(0deg) translateX(6px)}
.chip svg{width:30px;height:30px}
.chip b{font-family:var(--display);font-size:21px;font-weight:700;line-height:1.1}
.chip small{display:block;font-size:14px;opacity:.85}
.chip .n{margin-left:auto;font-weight:700;font-size:15px;opacity:.9;font-variant-numeric:tabular-nums}
@media (max-width:860px){.fan{flex-direction:row;overflow-x:auto;gap:10px;padding-bottom:6px;scroll-snap-type:x mandatory}
  .chip{flex:0 0 auto;transform:none;scroll-snap-align:start}.chip small,.chip .n{display:none}}

/* season strip */
.season{margin-top:34px;border-radius:var(--r-lg);background:var(--surface);padding:24px;display:grid;grid-template-columns:minmax(0,1fr) minmax(0,2fr);gap:20px;align-items:center}
@media (max-width:760px){.season{grid-template-columns:1fr}}
.season h2{margin:0;font-size:28px}
.season p{margin:6px 0 0;color:var(--muted);font-size:16px}
.season .links{display:flex;flex-wrap:wrap;gap:10px}
.pill{display:inline-flex;align-items:center;gap:8px;padding:10px 14px;border-radius:999px;background:var(--bg);border:1px solid var(--line);color:var(--ink);text-decoration:none;font-weight:700;font-size:16px}
.pill:hover{border-color:var(--cat);color:var(--cat-text)}
.pill svg{color:var(--cat-text);width:18px;height:18px}

/* category sections on home */
.catsec{margin-top:56px;scroll-margin-top:16px}
.cathead{display:flex;align-items:center;gap:14px;border-bottom:4px solid var(--cat);padding-bottom:12px}
.cathead .badge{width:46px;height:46px;border-radius:var(--r-sm);background:var(--cat);color:var(--on-cat);display:grid;place-items:center}
.cathead .badge svg{width:26px;height:26px}
.cathead h2{margin:0}
.cathead p{margin:2px 0 0;color:var(--muted);font-size:16px}
.list{display:grid;grid-template-columns:repeat(auto-fill,minmax(300px,1fr));gap:0 36px;margin-top:6px}
.row{display:block;padding:16px 0;border-bottom:1px solid var(--line);text-decoration:none;color:var(--ink)}
.row strong{display:block;font-family:var(--display);font-size:21px;font-weight:700;line-height:1.2}
.row span{display:block;color:var(--muted);font-size:16px;margin-top:2px}
.row:hover strong{color:var(--cat-text)}
.guides-grid .row strong{font-size:19px}

/* page band (calculator and guide pages) */
.band{background:var(--cat);color:var(--on-cat);position:relative;overflow:hidden}
.band .wrap{padding-block:30px 34px;position:relative}
.band .wm{position:absolute;right:max(18px,env(safe-area-inset-right,0px));top:50%;transform:translateY(-50%);width:170px;height:170px;opacity:.16}
@media (max-width:640px){.band .wm{width:110px;height:110px;top:30%}}
.band h1{color:var(--on-cat);max-width:20ch}
.band .lede{color:var(--on-cat);opacity:.92}
.crumbs{font-size:15px;margin:0 0 10px;color:var(--muted)}
.crumbs a{color:inherit}
.band .crumbs{color:var(--on-cat);opacity:.88}
.meta{font-size:15px;color:var(--muted);margin:10px 0 0}
.band .meta{color:var(--on-cat);opacity:.85}

main{padding-block:0 64px}
.plain{padding-block:36px 0}

/* calculator */
.calc{display:grid;grid-template-columns:minmax(0,1.2fr) minmax(0,1fr);gap:24px;margin-top:-18px;align-items:start;position:relative}
@media (max-width:820px){.calc{grid-template-columns:1fr;margin-top:18px}}
.form{background:var(--bg);border:1px solid var(--line);border-radius:var(--r-lg);padding:24px;display:grid;grid-template-columns:1fr 1fr;gap:18px 18px;box-shadow:0 10px 30px -18px rgba(23,32,42,.35)}
@media (max-width:480px){.form{grid-template-columns:1fr;padding:18px}}
.field{display:flex;flex-direction:column;gap:6px;min-width:0}
.field.full{grid-column:1/-1}
.field label{font-size:15px;font-weight:700;color:var(--ink)}
.inp{display:flex;align-items:stretch;border:1.5px solid var(--line);border-radius:var(--r-sm);background:var(--surface);overflow:hidden}
.inp:focus-within{border-color:var(--cat);background:var(--bg)}
.inp input,.inp select{flex:1;min-width:0;border:0;background:transparent;color:var(--ink);font:700 19px var(--body);padding:11px 12px;font-variant-numeric:tabular-nums}
.inp select{font-weight:400;font-size:17px}
.inp .u{display:flex;align-items:center;padding:0 12px;font-size:15px;color:var(--muted);border-left:1px solid var(--line)}
.result{background:color-mix(in srgb,var(--cat) 84%,#000);color:var(--on-cat);border-radius:var(--r-lg);padding:24px;position:sticky;top:16px}
.result .k{font-size:16px;font-weight:700;opacity:.9}
.result .main{font-family:var(--display);font-weight:800;font-size:clamp(40px,6vw,58px);line-height:1.05;margin:6px 0 2px;font-variant-numeric:tabular-nums;letter-spacing:-.02em}
.result .main mark{background:none;color:inherit}
.result dl{margin:16px 0 0;display:grid;gap:0}
.result dl div{display:flex;justify-content:space-between;gap:14px;border-top:1px solid rgba(255,255,255,.28);padding:10px 0}
.result dt{opacity:.9;font-size:16px}
.result dd{margin:0;font-weight:700;font-variant-numeric:tabular-nums;text-align:right}
.result .note{font-size:14px;opacity:.85;margin:14px 0 0;line-height:1.5}
.copy{margin-top:16px;font:700 15px var(--body);background:rgba(255,255,255,.16);color:var(--on-cat);border:1px solid rgba(255,255,255,.45);border-radius:999px;padding:9px 16px;cursor:pointer}
.copy:hover{background:rgba(255,255,255,.28)}

/* article layout with table of contents */
.doc{display:grid;grid-template-columns:minmax(0,1fr) 250px;gap:56px;margin-top:20px}
@media (max-width:980px){.doc{grid-template-columns:1fr;gap:0}.toc{display:none}}
.toc{position:sticky;top:20px;align-self:start;margin-top:44px;font-size:15px;border-left:3px solid var(--cat);padding-left:16px}
.toc b{display:block;font-family:var(--display);font-size:17px;margin-bottom:8px}
.toc a{display:block;color:var(--muted);text-decoration:none;padding:4px 0;line-height:1.35}
.toc a:hover{color:var(--cat-text)}
.guide{max-width:70ch}
.guide p,.guide li{color:var(--ink)}
.guide li{margin:4px 0}
.formula{background:var(--surface);border-left:5px solid var(--cat);padding:14px 16px;border-radius:0 var(--r-sm) var(--r-sm) 0;overflow-x:auto;font-weight:700}
.tbl{overflow-x:auto;margin:16px 0;border:1px solid var(--line);border-radius:var(--r-md)}
table{border-collapse:collapse;width:100%;font-size:16px}
th,td{text-align:left;padding:10px 14px;border-bottom:1px solid var(--line);vertical-align:top}
tr:last-child td{border-bottom:0}
th{font-size:15px;color:var(--ink);background:var(--surface)}
td{font-variant-numeric:tabular-nums}
details{border-bottom:1px solid var(--line);padding:14px 0}
summary{cursor:pointer;font-weight:700;font-size:18px}
details p{margin:8px 0 0}
.cta{display:flex;align-items:center;gap:16px;flex-wrap:wrap;background:var(--cat);color:var(--on-cat);border-radius:var(--r-lg);padding:20px 22px;margin-top:32px}
.cta p{margin:0;font-family:var(--display);font-size:22px;font-weight:700;color:var(--on-cat)}
.cta a{margin-left:auto;background:var(--bg);color:var(--ink);text-decoration:none;font-weight:700;padding:11px 18px;border-radius:999px}

/* related */
.related{display:grid;grid-template-columns:repeat(auto-fill,minmax(240px,1fr));gap:14px;margin-top:18px}
.rel{display:flex;gap:12px;align-items:flex-start;background:var(--surface);border-radius:var(--r-md);padding:16px;text-decoration:none;color:var(--ink)}
.rel .dot{width:36px;height:36px;border-radius:var(--r-sm);background:var(--cat);color:var(--on-cat);display:grid;place-items:center;flex:none}
.rel .dot svg{width:20px;height:20px}
.rel strong{display:block;font-family:var(--display);font-size:18px;line-height:1.2}
.rel span{display:block;font-size:14px;color:var(--muted);margin-top:4px}
.rel:hover strong{color:var(--cat-text)}

footer{border-top:1px solid var(--line);padding-block:34px;font-size:15px;color:var(--muted);background:var(--surface)}
footer .wrap{display:grid;grid-template-columns:minmax(0,1.3fr) minmax(0,1fr);gap:28px}
@media (max-width:700px){footer .wrap{grid-template-columns:1fr}}
.fcol{display:flex;flex-direction:column;gap:10px;min-width:0}
.fcol strong{font-family:var(--display);font-size:20px;color:var(--ink)}
.fcol nav{display:flex;flex-wrap:wrap;gap:8px 18px}
footer a{color:var(--muted)}
@media (prefers-reduced-motion:reduce){*{transition:none!important;animation:none!important}.chip{transform:none}}
.sr{position:absolute;width:1px;height:1px;overflow:hidden;clip:rect(0 0 0 0);white-space:nowrap}