/* ==========================================================================
   RoofFolio — visual system v3 “Pitch”
   ─ Worksheet paper for input and reading; a dark instrument for output.
   ─ One motif: a roof slope at a real pitch (the 6:12 wedge, the cut edge).
   ─ Type: Archivo across widths (condensed display + readouts, normal UI,
     expanded labels) and Source Serif 4 for reading and for variables.
   ─ Colour carries meaning: ink = object, steel = geometry/links,
     amber = the answer, rust = stale, red = error.
   All fonts self-hosted, SIL OFL 1.1. No inline styles (CSP).
   ========================================================================== */

@font-face{font-family:"Archivo";src:url(/assets/fonts/archivo-var.woff2) format("woff2");font-weight:400 800;font-stretch:62% 112%;font-display:swap}
@font-face{font-family:"Source Serif 4";src:url(/assets/fonts/source-serif-4-400.woff2) format("woff2");font-weight:400;font-style:normal;font-display:swap}
@font-face{font-family:"Source Serif 4";src:url(/assets/fonts/source-serif-4-400-italic.woff2) format("woff2");font-weight:400;font-style:italic;font-display:swap}
@font-face{font-family:"Source Serif 4";src:url(/assets/fonts/source-serif-4-greek-italic.woff2) format("woff2");font-weight:400;font-style:italic;unicode-range:U+0370-03FF;font-display:swap}

:root{
  /* paper side */
  --paper:#f0ede6; --paper-2:#e5e1d7; --sheet:#f8f6f1; --field:#fffdf8;
  --ink:#13181c; --ink-2:#343c43; --graphite:#595f66;
  --rule:#d3cec3; --rule-2:#aea89b;
  --steel:#255a8c; --steel-2:#1a4570; --steel-wash:#dce5ee;
  --amber:#f2a93b; --amber-ink:#8a4f00; --amber-wash:#fbebcf;
  --rust:#a2410f; --rust-wash:#f6e3d8;
  --error:#b42318; --error-wash:#fbe9e7;
  --ok:#2e7a55;
  /* instrument side */
  --night:#15212c; --night-2:#1c2b38; --night-line:#2e4152;
  --chalk:#e8ecee; --chalk-2:#a9b5bf; --sky:#8ab7dd; --amber-hi:#f5b554; --rust-hi:#f09a6c;

  --sans:"Archivo",system-ui,-apple-system,"Segoe UI",Roboto,sans-serif;
  --serif:"Source Serif 4","Iowan Old Style","Palatino Linotype",Palatino,serif;
  --gutter:clamp(16px,4vw,56px);
  --max:1360px;
  --cut:48px; /* 6:12 → 48 over 96 */
}

*,*::before,*::after{box-sizing:border-box}
html{scroll-behavior:smooth;scroll-padding-top:24px;-webkit-text-size-adjust:100%}
body{margin:0;background:var(--paper);color:var(--ink);font:400 16px/1.55 var(--sans);font-stretch:100%;-webkit-font-smoothing:antialiased;text-rendering:optimizeLegibility;overflow-x:hidden;font-variant-numeric:lining-nums}
a{color:var(--steel);text-decoration-thickness:1px;text-underline-offset:.2em}
a:hover{color:var(--steel-2);text-decoration-thickness:2px}
button,input,select,summary{font:inherit;color:inherit}
button,a,input,select,summary{touch-action:manipulation}
button{cursor:pointer}
button:disabled{cursor:not-allowed;opacity:.4}
:focus-visible{outline:2px solid var(--steel);outline-offset:3px}
::selection{background:var(--amber-wash);color:var(--ink)}
h1,h2,h3,p,figure{margin-top:0}
p{margin-bottom:1em}
var,.sym{font:italic 400 1.08em/1 var(--serif);letter-spacing:0}
.vh{position:absolute!important;width:1px;height:1px;overflow:hidden;clip:rect(0 0 0 0);clip-path:inset(50%);white-space:nowrap}
[hidden]{display:none!important}
.skip{position:absolute;left:12px;top:-80px;background:var(--ink);color:var(--paper);padding:12px 16px;z-index:30;font-weight:600}
.skip:focus{top:12px}
.wrap{max-width:var(--max);margin-inline:auto;padding-inline:var(--gutter)}
main{min-height:60vh}

/* ---------- voices ---------- */
.kicker,.label,.ws-units,.th-pos,.aside-h,.mn-h,.scope-k,.ft-h,.tm-h,.lim-h,.example-tag,.limits-h,.handoff-h,.result-label,.sched-title,.drawing-caption,.hi-top,.ro-label,.st-out,.tt,.map-side span{font:600 11px/1.3 var(--sans);font-stretch:112%;letter-spacing:.09em;text-transform:uppercase}
.kicker{color:var(--graphite);margin:0 0 12px}
.deck{font:400 clamp(18px,1.5vw,21px)/1.5 var(--serif);color:var(--ink-2);max-width:36em}
.help,.field small{display:block;color:var(--graphite);font-size:13px;line-height:1.45;margin:6px 0 0}
.stage{display:inline-grid;place-items:center;width:20px;height:20px;border-radius:50%;background:var(--ink);color:var(--paper);font:700 11px/1 var(--sans);font-stretch:87%;letter-spacing:0;flex:none;margin-right:10px;vertical-align:1px}

/* ---------- brand ---------- */
.brand{display:inline-flex;align-items:flex-end;gap:9px;color:var(--ink);text-decoration:none;line-height:1}
.brand:hover{color:var(--ink)}
.mark{width:34px;height:21px;flex:none;margin-bottom:3px}
.mk-wedge{fill:var(--amber)}
.mk-base{stroke:currentColor;stroke-width:1.5}
.wordmark{font:800 27px/1 var(--sans);font-stretch:66%;letter-spacing:-.005em}
.wordmark span{font-weight:400}
.brand-lg .wordmark{font-size:44px}
.brand-lg .mark{width:54px;height:33px;margin-bottom:5px}

/* ---------- masthead ---------- */
.masthead{background:var(--paper);border-bottom:1px solid var(--ink);position:relative;z-index:10}
.mh-inner{max-width:var(--max);margin:auto;padding:0 var(--gutter);display:flex;align-items:center;gap:28px;min-height:64px}
.tools-inline{display:flex;align-items:center;gap:0;margin-left:auto;align-self:stretch}
.ti-group{display:flex;align-items:stretch}
.ti-label{display:flex;align-items:center;font:italic 400 14px/1 var(--serif);color:var(--graphite);padding-right:10px}
.tools-inline a{display:flex;align-items:center;padding:0 10px;color:var(--ink);text-decoration:none;font-size:14.5px;font-weight:500;position:relative;white-space:nowrap}
.tools-inline a::after{content:"";position:absolute;left:10px;right:10px;bottom:-1px;height:3px;background:transparent}
.tools-inline a:hover::after{background:var(--rule-2)}
.tools-inline a[aria-current]{font-weight:700}
.tools-inline a[aria-current]::after{background:var(--amber)}
.ti-ridge{width:34px;align-self:center;height:18px;margin:0 8px;background:linear-gradient(to top left,transparent calc(50% - .75px),var(--ink) calc(50% - .75px),var(--ink) calc(50% + .75px),transparent calc(50% + .75px)) left/50% 100% no-repeat,linear-gradient(to top right,transparent calc(50% - .75px),var(--ink) calc(50% - .75px),var(--ink) calc(50% + .75px),transparent calc(50% + .75px)) right/50% 100% no-repeat}
.site-nav{display:flex;gap:2px;padding-left:18px;border-left:1px solid var(--rule-2)}
.site-nav a{color:var(--ink-2);text-decoration:none;font-size:14.5px;padding:8px 8px}
.site-nav a:hover{color:var(--ink);text-decoration:underline;text-underline-offset:6px}
.tools-menu{display:none;margin-left:auto}
.tools-menu summary{list-style:none;display:flex;align-items:center;gap:10px;cursor:pointer;min-height:44px;padding:0 4px 0 14px;border-left:1px solid var(--rule-2);font-weight:600;font-size:15px}
.tools-menu summary::-webkit-details-marker{display:none}
.tools-menu summary::after{content:"";width:18px;height:10px;background:linear-gradient(to top right,transparent 46%,var(--ink) 46%,var(--ink) 58%,transparent 58%) left/50% 100% no-repeat,linear-gradient(to top left,transparent 46%,var(--ink) 46%,var(--ink) 58%,transparent 58%) right/50% 100% no-repeat;transition:transform .15s}
.tools-menu[open] summary::after{transform:scaleY(-1)}
.tm-panel{position:absolute;left:0;right:0;top:100%;background:var(--paper);border-bottom:1px solid var(--ink);padding:8px var(--gutter) 18px;box-shadow:0 18px 30px -24px rgba(19,24,28,.5)}
.tm-group{padding-top:12px}
.tm-h{color:var(--ink);margin:0 0 4px;display:flex;gap:10px;align-items:baseline}
.tm-h span{font:italic 400 13px var(--serif);text-transform:none;letter-spacing:0;color:var(--graphite)}
.tm-panel ul{list-style:none;margin:0;padding:0}
.tm-panel li a{display:grid;grid-template-columns:22px 1fr;gap:0 8px;padding:9px 0;border-top:1px solid var(--rule);text-decoration:none;color:var(--ink)}
.tm-n{grid-row:1/3;font:700 13px/1.3 var(--sans);font-stretch:70%;color:var(--amber-ink)}
.tm-t{font-weight:600;font-size:15.5px}
.tm-o{font-size:13px;color:var(--graphite)}
.tm-panel li a[aria-current] .tm-t{text-decoration:underline;text-decoration-color:var(--amber);text-decoration-thickness:3px;text-underline-offset:5px}
.tm-foot{display:flex;flex-wrap:wrap;gap:6px 18px;margin:14px 0 0;padding-top:12px;border-top:1px solid var(--ink);font-size:14px}

/* ---------- buttons ---------- */
.button,.primary{display:inline-flex;align-items:center;justify-content:center;gap:14px;background:var(--ink);color:var(--paper);border:0;border-radius:0;min-height:52px;padding:14px 22px;font:700 16px/1.1 var(--sans);font-stretch:87%;letter-spacing:.01em;text-decoration:none;transition:background-color .15s}
.button:hover,.primary:hover{background:var(--steel-2);color:#fff}
.button::after{content:"";width:16px;height:10px;background:var(--amber);clip-path:polygon(0 100%,100% 100%,100% 0)}
.btn-wedge{width:16px;height:10px;fill:var(--amber)}
.text-button{border:0;background:transparent;padding:6px 0;color:var(--steel);text-decoration:underline;text-underline-offset:4px;font-size:14.5px;font-weight:500;min-height:44px}
.text-button:hover{color:var(--steel-2);text-decoration-thickness:2px}
.secondary{display:flex;align-items:center;justify-content:center;gap:8px;width:100%;border:1px dashed var(--ink-2);color:var(--ink);background:transparent;padding:10px 16px;min-height:46px;font-weight:600;font-size:14.5px;margin-top:16px}
.secondary:hover{border-style:solid;background:var(--sheet)}
.quiet{font-weight:600;font-size:15px}

/* ==========================================================================
   HOMEPAGE
   ========================================================================== */
.hero{display:grid;grid-template-columns:minmax(0,4.7fr) minmax(0,7.3fr);gap:clamp(28px,3.5vw,56px);align-items:center;padding-top:clamp(28px,4vw,56px);padding-bottom:clamp(56px,7vw,104px)}
.hero-eyebrow{font:600 11.5px/1.3 var(--sans);font-stretch:112%;letter-spacing:.1em;text-transform:uppercase;color:var(--ink-2);margin:0 0 20px;display:flex;align-items:center;gap:10px}
.hero-eyebrow::before{content:"";width:22px;height:11px;background:var(--amber);clip-path:polygon(0 100%,100% 100%,100% 0);flex:none}
.hero-h1{font:800 clamp(44px,4.9vw,72px)/.9 var(--sans);font-stretch:62%;letter-spacing:-.005em;margin:0 0 24px}
.hero-h1 span{display:block;white-space:nowrap}
.hero-h1 .l2{color:var(--amber-ink)}
.hero-dek{font:400 19px/1.45 var(--serif);color:var(--ink-2);max-width:23em;margin:0 0 26px}
.flow{list-style:none;margin:0 0 30px;padding:14px 0;border-top:1px solid var(--ink);border-bottom:1px solid var(--rule);display:flex;flex-wrap:wrap;align-items:center;gap:8px 0}
.flow li{display:flex;align-items:center;font:700 16px/1 var(--sans);font-stretch:87%;color:var(--ink)}
.flow li+li::before{content:"";width:26px;height:8px;margin:0 14px 0 12px;background:var(--graphite);clip-path:polygon(0 45%,78% 45%,78% 0,100% 50%,78% 100%,78% 55%,0 55%)}
.flow .stage{margin-right:8px}
.hero-go{display:flex;flex-wrap:wrap;align-items:center;gap:12px 22px;margin:0}

/* the instrument (shared by hero and tool pages) */
.inst-dark,.inst{background:var(--night);color:var(--chalk);position:relative}
.inst-dark a,.inst a{color:var(--chalk)}
.inst-dark :focus-visible,.inst :focus-visible{outline-color:var(--amber)}
.inst-cut{position:absolute;top:0;width:96px;height:var(--cut);pointer-events:none}
.inst-cut span{position:absolute;font:600 10px/1 var(--sans);font-stretch:112%;letter-spacing:.08em;color:var(--graphite);white-space:nowrap}
.hero-inst{margin:0;clip-path:polygon(0 var(--cut),96px 0,100% 0,100% 100%,0 100%);padding:0}
.hero-inst .inst-cut{left:0}
.hero-inst .inst-cut span{left:10px;top:-2px;transform:rotate(-26.565deg);transform-origin:left top;display:none}
.hi-top{display:flex;justify-content:space-between;gap:12px;padding:16px 24px 0 120px;color:var(--chalk-2)}
.hi-tool{color:var(--chalk)}
.hi-measure{display:flex;flex-wrap:wrap;align-items:center;gap:8px;padding:18px 24px 0 24px}
.hi-measure .stage,.hi-bottom .stage,.inst .stage{background:var(--amber);color:var(--night)}
.chip{display:inline-flex;align-items:baseline;gap:6px;border:1px solid var(--night-line);padding:5px 10px;font:600 14px/1.1 var(--sans);font-stretch:87%;color:var(--chalk);font-variant-numeric:tabular-nums}
.chip var{color:var(--amber-hi);font-size:17px}
.hi-draw{padding:4px 12px 0}
.hi-art-narrow{display:none}
.hi-art-narrow .dg,.drawing .dg.compact{max-width:520px;margin-inline:auto}
.hi-bottom{display:grid;grid-template-columns:1fr auto;gap:0;border-top:1px solid var(--night-line);margin-top:4px}
.hi-calc{grid-column:1/-1;padding:12px 24px;border-bottom:1px solid var(--night-line);display:flex;align-items:center;font-size:15px;color:var(--chalk-2);font-variant-numeric:tabular-nums}
.hi-calc-line var{color:var(--chalk);font-size:18px}
.hi-calc-line b{color:var(--amber-hi);font-weight:700}
.hi-result{padding:18px 24px 22px;display:grid;grid-template-columns:auto 1fr;column-gap:0;align-items:baseline}
.hi-result .stage{grid-row:1}
.ro-label{color:var(--amber-hi)}
.ro-value{grid-column:1/-1;font:700 clamp(58px,6vw,88px)/.95 var(--sans);font-stretch:62%;color:var(--amber);letter-spacing:-.01em;margin:6px 0 10px;font-variant-numeric:tabular-nums}
.ro-value small{font:500 .26em var(--sans);font-stretch:100%;color:var(--chalk-2);margin-left:10px;letter-spacing:0}
.ro-flag{grid-column:1/-1;border-left:3px solid var(--amber);padding:2px 0 2px 12px;font-size:15px;line-height:1.4;color:var(--chalk);max-width:30em}
.hi-next{border-left:1px solid var(--night-line);padding:18px 24px;display:flex;flex-direction:column;gap:10px;justify-content:flex-end;min-width:230px}
.hi-next a{font-weight:600;text-decoration:none;display:flex;justify-content:space-between;gap:16px;padding-bottom:8px;border-bottom:1px solid var(--night-line)}
.hi-next a::after{content:"→";color:var(--amber)}
.hi-next a:hover{color:#fff;border-bottom-color:var(--amber)}
.hi-next .stage{margin-bottom:6px}

/* six tools on one roof */
.map{padding-top:clamp(40px,5vw,72px);padding-bottom:clamp(56px,7vw,96px)}
.map-head{border-top:2px solid var(--ink);padding-top:22px}
.map-head{display:grid;grid-template-columns:minmax(0,5fr) minmax(0,6fr);gap:16px 56px;align-items:end;margin-bottom:clamp(36px,5vw,64px)}
.map-head h2,.chain-head h2,.refs-head h2{font:800 clamp(36px,4.4vw,64px)/.92 var(--sans);font-stretch:66%;margin:0;letter-spacing:-.005em}
.map-head p,.chain-head p,.refs-head p{font:400 18px/1.5 var(--serif);color:var(--ink-2);margin:0;max-width:32em}
.map-stage{position:relative;--roof:230px}
.map-roof{position:absolute;left:0;right:0;top:0;width:100%;height:var(--roof);overflow:visible}
.mr-line{fill:none;stroke:var(--ink);stroke-width:2.5;vector-effect:non-scaling-stroke;stroke-linejoin:miter}
.mr-base{fill:none;stroke:var(--rule-2);stroke-width:1;stroke-dasharray:4 5;vector-effect:non-scaling-stroke}
.map-ridge{position:absolute;left:50%;top:-58px;transform:translateX(-50%);display:flex;align-items:baseline;gap:8px;white-space:nowrap;background:var(--paper);padding:0 10px}
.mf-sym{font:italic 400 40px/1 var(--serif);color:var(--amber-ink)}
.mf-eq{font:500 19px/1 var(--sans);color:var(--ink)}
.mf-eq i{font-family:var(--serif)}
.map-side{position:absolute;top:calc(var(--roof) * .42);margin:0;font:700 22px/1 var(--sans);font-stretch:70%;display:flex;flex-direction:column;gap:4px}
.map-side span{color:var(--graphite)}
.ms-g{left:0}.ms-m{right:0;text-align:right}
.map-list{list-style:none;margin:0;padding:0;display:grid;grid-template-columns:repeat(6,minmax(0,1fr));position:relative}
.st{position:relative;padding-top:calc(var(--roof) + 26px)}
.st-node{position:absolute;left:50%;top:calc(var(--roof) * var(--k));width:14px;height:14px;margin:-7px 0 0 -7px;border-radius:50%;background:var(--paper);border:2.5px solid var(--ink);z-index:2}
.st-1,.st-6{--k:.8333}.st-2,.st-5{--k:.5}.st-3,.st-4{--k:.1667}
.st::before{content:"";position:absolute;left:50%;top:calc(var(--roof) * var(--k) + 8px);bottom:calc(100% - var(--roof) - 18px);border-left:1px solid var(--rule-2)}
.st-link{display:block;padding:0 14px;text-decoration:none;color:var(--ink);text-align:center}
.st-n{display:block;font:700 13px/1 var(--sans);font-stretch:70%;color:var(--amber-ink);margin-bottom:8px}
.st-link strong{display:block;font:750 21px/1.08 var(--sans);font-stretch:80%;margin-bottom:8px}
.st-out{display:block;color:var(--steel);margin-bottom:8px;font-size:10px}
.st-d{display:block;font:400 15px/1.45 var(--serif);color:var(--ink-2)}
.st-link:hover strong{text-decoration:underline;text-decoration-color:var(--amber);text-decoration-thickness:3px;text-underline-offset:5px}
.st:has(.st-link:hover) .st-node,.st:has(.st-link:focus-visible) .st-node{background:var(--amber);border-color:var(--ink)}

/* the chain, set as one equation */
.chain{background:var(--paper-2);padding:clamp(56px,7vw,96px) 0;border-top:1px solid var(--rule-2);border-bottom:1px solid var(--rule-2)}
.chain-head{display:grid;grid-template-columns:minmax(0,5fr) minmax(0,6fr);gap:16px 56px;align-items:end;margin-bottom:44px}
.eqn{display:flex;flex-wrap:wrap;align-items:flex-start;gap:18px 0;border-top:2px solid var(--ink);padding-top:26px}
.term{display:flex;flex-direction:column;text-decoration:none;color:var(--ink);padding:0 4px;min-width:0}
.tv{font:700 clamp(32px,3.3vw,50px)/.95 var(--sans);font-stretch:62%;font-variant-numeric:tabular-nums;white-space:nowrap}
.tv small{font:500 15px var(--sans);font-stretch:100%;color:var(--graphite);letter-spacing:0}
.tl{font-weight:600;font-size:14.5px;margin-top:10px}
.tn{font:italic 400 14.5px/1.35 var(--serif);color:var(--graphite)}
.tt{margin-top:10px;color:var(--steel);font-size:10px}
.term:hover .tv{color:var(--steel-2)}
.term:last-of-type .tv{color:var(--amber-ink)}
.opr{font:400 clamp(26px,2.8vw,42px)/1.1 var(--sans);font-stretch:70%;color:var(--amber-ink);padding:0 clamp(6px,1vw,16px);white-space:nowrap}
.chain-foot{margin:30px 0 0;font:italic 400 15px/1.5 var(--serif);color:var(--graphite);max-width:52em}

/* reference sheets */
.refs{padding-top:clamp(56px,7vw,96px);padding-bottom:clamp(40px,5vw,72px)}
.refs-head{display:grid;grid-template-columns:minmax(0,5fr) minmax(0,6fr);gap:16px 56px;align-items:end;margin-bottom:40px}
.ref-list{list-style:none;margin:0;padding:0;display:grid;grid-template-columns:repeat(3,minmax(0,1fr));border-top:2px solid var(--ink)}
.ref-list li+li{border-left:1px solid var(--rule-2)}
.ref-item{display:grid;grid-template-columns:auto 1fr;gap:4px 16px;padding:24px 26px 30px;text-decoration:none;color:var(--ink);height:100%}
.ref-list li:first-child .ref-item{padding-left:0}
.ref-list li:last-child .ref-item{padding-right:0}
.ref-fig{grid-column:1/-1;display:block;height:150px;margin-bottom:18px;border-bottom:1px solid var(--rule)}
.ref-fig .dg{height:100%;width:100%}
.ref-no{grid-row:2/4;font:800 50px/.9 var(--sans);font-stretch:62%;color:var(--steel)}
.ref-title{font:400 23px/1.2 var(--serif)}
.ref-desc{font-size:14.5px;line-height:1.5;color:var(--graphite)}
.ref-item:hover .ref-title{text-decoration:underline;text-decoration-color:var(--amber);text-decoration-thickness:2px;text-underline-offset:4px}

/* scope statement */
.scope{padding-top:clamp(40px,5vw,64px);padding-bottom:clamp(64px,8vw,112px);display:grid;grid-template-columns:minmax(0,5fr) minmax(0,7fr);gap:32px 56px;align-items:start}
.scope-state{font:800 clamp(30px,3.4vw,48px)/.98 var(--sans);font-stretch:66%;margin:0}
.scope-state span{display:block;color:var(--amber-ink)}
.scope-cols{display:grid;grid-template-columns:1fr 1fr;gap:0 40px}
.scope-k{color:var(--ink);margin-bottom:12px;padding-bottom:10px;border-bottom:2px solid var(--ink)}
.scope ul{list-style:none;margin:0;padding:0}
.scope li{padding:9px 0 9px 22px;border-bottom:1px solid var(--rule);position:relative;font:400 16.5px/1.4 var(--serif)}
.scope li::before{content:"";position:absolute;left:0;top:15px;width:11px;height:7px;background:var(--steel);clip-path:polygon(0 100%,100% 100%,100% 0)}
.scope-not li::before{background:none;border-top:1.5px solid var(--rust);width:10px;height:0;top:19px;clip-path:none}
.scope-more{grid-column:2;margin:0;font-weight:600}

/* ==========================================================================
   TOOL PAGES
   ========================================================================== */
.crumbs{display:flex;flex-wrap:wrap;gap:8px;font-size:13px;color:var(--graphite);padding:20px 0 0}
.crumbs a{color:var(--graphite)}
.crumbs span[aria-hidden]{color:var(--rule-2)}
.tool-head{display:grid;grid-template-columns:minmax(0,1fr) auto;gap:20px 56px;align-items:end;padding:22px 0 30px}
.tool-head h1{font:800 clamp(44px,5.6vw,80px)/.88 var(--sans);font-stretch:62%;margin:0 0 16px;letter-spacing:-.005em}
.th-dek{font:400 clamp(18px,1.5vw,20px)/1.5 var(--serif);color:var(--ink-2);margin:0;max-width:34em}
.th-side{display:flex;flex-direction:column;align-items:flex-end;gap:14px}
.th-map{display:flex;flex-direction:column;align-items:flex-end;gap:8px}
.roofmap{width:220px;height:auto;overflow:visible}
.rm-line{fill:none;stroke:var(--ink);stroke-width:1.6}
.rm-base{fill:none;stroke:var(--rule-2);stroke-dasharray:3 4}
.rm-f{font:italic 400 13px var(--serif);fill:var(--amber-ink)}
.rm-node{fill:var(--paper);stroke:var(--ink);stroke-width:1.5}
.rm-node.is-before{fill:var(--ink)}
.rm-node.is-here{fill:var(--amber);stroke:var(--ink);stroke-width:2}
.th-pos{color:var(--graphite);margin:0;text-align:right}
.th-group{color:var(--ink)}
.th-step{display:flex;gap:18px;margin:0;font-size:14px}
.th-step a{color:var(--ink-2);text-decoration:none;border-bottom:1px solid var(--rule-2);padding-bottom:2px}
.th-step a:hover{color:var(--ink);border-bottom-color:var(--amber)}
.noscript{background:var(--rust-wash);color:var(--rust);padding:14px 16px;margin-bottom:20px}

.bench{display:grid;grid-template-columns:minmax(300px,410px) minmax(0,1fr);gap:0 clamp(28px,3.4vw,52px);align-items:start;margin-bottom:clamp(64px,8vw,112px)}

/* worksheet (inputs) */
.worksheet{border-top:2px solid var(--ink);padding-top:16px;min-width:0}
.ws-head{display:flex;align-items:center;justify-content:space-between;gap:12px}
.ws-head h2,.inst-head h2{font:800 22px/1 var(--sans);font-stretch:75%;margin:0;display:flex;align-items:center}
.ws-units{color:var(--graphite);margin:4px 0 18px}
.setup{display:grid;grid-template-columns:1fr 1fr;gap:0 12px;margin-bottom:6px;padding-bottom:6px;border-bottom:1px solid var(--rule)}
.setup>.field:only-child{grid-column:1/-1}
.setup .field small{display:none}
.setup .field{margin-bottom:12px}
.field{margin:0 0 20px;min-width:0}
fieldset{padding:0;border:0;margin:0;min-width:0}
.field>label,.field>legend{display:flex;align-items:baseline;gap:6px;font-size:14.5px;font-weight:600;line-height:1.3;margin-bottom:7px;padding:0}
.field>legend{float:left;width:100%}
.field>legend+*{clear:both}
.field .sym{color:var(--amber-ink);font-size:18px;margin-left:auto;padding-left:8px}
.input-shell{display:flex;align-items:stretch;background:var(--field);border:1px solid var(--rule-2);border-bottom:2px solid var(--ink);min-height:48px;transition:border-color .12s,background-color .12s}
.input-shell:hover{border-color:var(--ink-2)}
.input-shell:focus-within{outline:2px solid var(--steel);outline-offset:2px;border-color:var(--ink)}
.input-shell input{border:0;width:100%;min-width:0;padding:10px 12px;font:600 18px/1.2 var(--sans);font-stretch:87%;font-variant-numeric:tabular-nums;background:transparent;color:var(--ink);outline:0;border-radius:0}
.input-shell span{display:flex;align-items:center;padding:0 12px 0 4px;font-size:14px;color:var(--graphite);white-space:nowrap}
.input-shell span:empty{display:none}
.input-shell b{font-weight:500}
.select-shell{position:relative}
.select-shell::after{content:"";position:absolute;right:14px;top:50%;width:12px;height:7px;margin-top:-3px;background:var(--ink);clip-path:polygon(0 0,100% 0,50% 100%);pointer-events:none}
select{appearance:none;-webkit-appearance:none;width:100%;padding:10px 38px 10px 12px;border:1px solid var(--rule-2);border-bottom:2px solid var(--ink);border-radius:0;background:var(--field);color:var(--ink);min-height:48px;font-size:15px;font-weight:500}
select:hover{border-color:var(--ink-2)}
select:focus-visible{outline:2px solid var(--steel);outline-offset:2px}
.measure-pair{display:grid;grid-template-columns:1fr 1fr;gap:8px}
.measure-pair label,.measurement>label.help{display:block;font-size:12px;color:var(--graphite);margin:0 0 4px}
.error{color:var(--error);font-size:13.5px;font-weight:600;margin-top:7px;display:flex;gap:8px;align-items:flex-start}
.error::before{content:"";width:12px;height:12px;background:var(--error);clip-path:polygon(50% 0,100% 100%,0 100%);flex:none;margin-top:3px}
.error:empty{display:none}
.input-shell:has([aria-invalid=true]),[aria-invalid=true]{background:var(--error-wash)}
.input-shell:has([aria-invalid=true]){border-color:var(--error)}
.form-message{color:var(--error);font-size:14px;font-weight:600;border-left:3px solid var(--error);padding:9px 12px;background:var(--error-wash)}
.form-message:empty{display:none}
.import-note{background:var(--steel-wash);border-left:3px solid var(--steel);font-size:14px;padding:11px 14px;margin-bottom:16px}
.import-note:empty{display:none}
.form-note{font:400 16px/1.45 var(--serif);color:var(--ink-2);margin:0 0 6px}
.allowance-block{position:relative;padding-left:14px;margin-left:-14px;border-left:3px solid var(--amber)}
.coverage-block{margin-top:4px}
.coverage-note{background:var(--amber-wash);border-left:3px solid var(--amber-ink);padding:12px 14px;margin:0 0 16px;font:400 15.5px/1.45 var(--serif);color:var(--ink)}
.coverage-note strong{font:700 14px var(--sans);display:block;margin-bottom:2px}
.actions{display:flex;align-items:center;gap:18px;margin-top:24px}
.actions .primary{flex:1}
.local-note{font-size:12.5px;color:var(--graphite);margin:10px 0 0}
.section-entry{padding:16px 0 4px;margin-top:6px;border-top:1px solid var(--ink)}
.section-entry>legend{font:600 11px/1 var(--sans);font-stretch:112%;letter-spacing:.09em;text-transform:uppercase;color:var(--steel);float:left;margin-bottom:10px}
.section-title{clear:both;display:flex;justify-content:space-between;align-items:center;margin-bottom:8px;gap:12px}
.section-title h3{margin:0;font:700 16px/1.2 var(--sans);font-stretch:87%}
.section-title button{font-size:13.5px}
.tiny{font:600 11px/1 var(--sans)}

/* instrument (results) */
.inst{clip-path:polygon(0 0,calc(100% - 96px) 0,100% var(--cut),100% 100%,0 100%);padding:22px clamp(20px,2.6vw,36px) 30px;min-width:0}
.inst .inst-cut{right:0}
.inst-head{display:flex;justify-content:space-between;align-items:center;gap:10px 20px;flex-wrap:wrap;padding:0 90px 16px 0;border-bottom:1px solid var(--night-line);margin-bottom:22px}
.inst-head h2{color:var(--chalk)}
.inst-head .amp{font:italic 400 1em var(--serif);margin:0 .2em;color:var(--chalk-2)}
.result-status{font-size:13px;color:var(--chalk-2);display:flex;gap:8px;align-items:baseline;max-width:100%}
.result-status::before{content:"";width:8px;height:8px;border-radius:50%;background:var(--night-line);flex:none;transform:translateY(-1px)}
.inst:has(.result-number) .result-status::before{background:var(--amber)}
.result-status.stale{color:var(--rust-hi);background:rgba(240,154,108,.1);padding:6px 10px;border-left:3px solid var(--rust-hi)}
.result-status.stale::before{background:var(--rust-hi)}

.result-body{display:grid;grid-template-columns:minmax(0,1.15fr) minmax(0,1fr);grid-template-rows:auto auto auto auto auto auto 1fr;column-gap:clamp(24px,3vw,48px);align-items:start}
.result-body>*{grid-column:1}
.print-summary{display:none}
.result-label{color:var(--amber-hi);margin:0}
.result-number{display:flex;align-items:baseline;flex-wrap:wrap;gap:0 12px;font:700 clamp(64px,7vw,108px)/.92 var(--sans);font-stretch:62%;color:var(--amber);margin:8px 0 14px;font-variant-numeric:tabular-nums;overflow-wrap:anywhere;letter-spacing:-.01em}
.result-number.is-long{font-size:clamp(52px,5.2vw,80px)}
.result-number.is-xlong{font-size:clamp(40px,4vw,60px)}
.result-number .u{font:500 .24em/1 var(--sans);font-stretch:100%;color:var(--chalk-2);letter-spacing:0}
.result-flag{border-left:3px solid var(--amber);padding:2px 0 2px 12px;margin:0 0 14px;font-size:15.5px;line-height:1.4;font-weight:600;color:var(--chalk);max-width:34em}
.calc-line{display:flex;flex-direction:column;gap:3px;margin:0 0 14px;padding:10px 0;border-top:1px solid var(--night-line);border-bottom:1px solid var(--night-line);font-variant-numeric:tabular-nums}
.cl-k{font:600 10.5px/1.3 var(--sans);font-stretch:112%;letter-spacing:.09em;text-transform:uppercase;color:var(--chalk-2)}
.cl-v{font-size:16px;color:var(--chalk);overflow-wrap:anywhere}
.cl-v var{color:var(--chalk);font-size:19px}
.cl-v b{color:var(--amber-hi)}
.result-note{font:400 16.5px/1.45 var(--serif);color:var(--chalk);margin:0 0 8px;max-width:34em}
.result-sub{font-size:12.5px;color:var(--chalk-2)}
.schedules{grid-column:2;grid-row:1/-1;display:grid;gap:18px;align-content:start;min-width:0}
.sched-title{color:var(--chalk-2);margin:0;padding-bottom:7px;border-bottom:1px solid var(--chalk-2);display:flex;align-items:center;gap:8px}
.sched-measured .sched-title::before{content:"";width:14px;height:8px;background:var(--sky)}
.sched-allow .sched-title{color:var(--amber-hi);border-bottom-color:var(--amber)}
.sched-allow .sched-title::before{content:"";width:14px;height:8px;background:repeating-linear-gradient(135deg,var(--amber) 0 1.5px,transparent 1.5px 4px);outline:1px solid var(--amber)}
.sched-round .sched-title::before{content:"";width:14px;height:8px;outline:1px solid var(--chalk-2);background:repeating-linear-gradient(135deg,var(--chalk-2) 0 1px,transparent 1px 5px)}
.sched-excluded .sched-title{border-bottom-style:dashed}
.schedule{margin:0}
.schedule>div{display:flex;justify-content:space-between;align-items:baseline;gap:16px;padding:8px 0;border-bottom:1px solid var(--night-line)}
.schedule dt{color:var(--chalk-2);font-size:14px;line-height:1.35}
.schedule dd{margin:0;text-align:right;font:600 16px/1.3 var(--sans);font-stretch:80%;font-variant-numeric:tabular-nums;color:var(--chalk);overflow-wrap:anywhere}
.inst:has(.result-status.stale) .result-number{color:var(--chalk-2);opacity:.55}
.inst:has(.result-status.stale) .schedules,.inst:has(.result-status.stale) .calc-line{opacity:.45}
.empty-result{grid-column:1/-1;color:var(--chalk-2);font:400 17px/1.45 var(--serif);margin:12px 0 4px;max-width:30em}
.readout-rule{grid-column:1/-1;height:2px;width:min(360px,80%);margin:34px 0 18px;background:linear-gradient(90deg,var(--night-line),var(--night-line)) center/100% 1px no-repeat;position:relative}
.readout-rule::before,.readout-rule::after{content:"";position:absolute;top:-4px;width:9px;height:9px;background:var(--chalk-2);clip-path:polygon(0 50%,100% 0,100% 100%)}
.readout-rule::before{left:0}.readout-rule::after{right:0;transform:scaleX(-1)}
.drawing{margin:26px 0 0;padding:14px 0 0;border-top:1px solid var(--night-line)}
.drawing .dg{max-height:430px}
.drawing-caption{display:flex;justify-content:space-between;gap:15px;color:var(--chalk-2);padding-top:8px;font-size:10px}
.limits-note{margin-top:20px;padding:14px 16px 14px 22px;background:var(--night-2);position:relative}
.limits-note::before{content:"";position:absolute;left:0;top:0;bottom:0;width:6px;background:repeating-linear-gradient(135deg,var(--chalk-2) 0 1px,transparent 1px 5px);opacity:.7}
.limits-h{color:var(--chalk);margin:0 0 6px;display:flex;align-items:center}
.limits-h .stage{width:18px;height:18px;font-size:10px}
.scope-note{font-size:14px;line-height:1.5;color:var(--chalk);margin:0}
.result-actions{display:flex;gap:8px;flex-wrap:wrap;margin-top:18px}
.tool-button{border:1px solid var(--chalk-2);background:transparent;color:var(--chalk);min-height:42px;padding:8px 14px;font:600 13.5px/1 var(--sans);font-stretch:87%}
.tool-button:hover:not(:disabled){background:var(--chalk);color:var(--night)}
.handoffs{margin-top:22px}
.handoffs:empty{display:none}
.handoff-h{color:var(--chalk);margin:0 0 6px;display:flex;align-items:center}
.handoff-h .stage{width:18px;height:18px;font-size:10px}
.handoffs a{display:grid;grid-template-columns:30px 1fr auto;align-items:center;gap:10px;padding:13px 0;border-top:1px solid var(--night-line);text-decoration:none;font-weight:700;font-size:17px;font-stretch:87%}
.handoffs a:last-child{border-bottom:1px solid var(--night-line)}
.ho-n{font:700 13px/1 var(--sans);font-stretch:70%;color:var(--amber-hi)}
.ho-a{color:var(--amber)}
.handoffs a:hover .ho-t{text-decoration:underline;text-decoration-color:var(--amber);text-underline-offset:4px}

/* ---------- method (below the bench) ---------- */
.method{display:grid;grid-template-columns:220px minmax(0,800px);gap:clamp(28px,5vw,88px);margin-bottom:clamp(64px,8vw,112px);counter-reset:sec}
.method-nav{align-self:start;position:sticky;top:24px}
.mn-h{margin:0 0 10px;color:var(--ink)}
.method-nav ol,.toc{list-style:none;margin:0;padding:0;counter-reset:toc}
.method-nav li,.toc li{counter-increment:toc}
.method-nav a,.toc a{display:grid;grid-template-columns:26px 1fr;padding:7px 0;color:var(--ink-2);text-decoration:none;font-size:14.5px;line-height:1.35;border-top:1px solid var(--rule)}
.method-nav a::before,.toc a::before{content:counter(toc);font:700 13px/1.5 var(--sans);font-stretch:70%;color:var(--amber-ink)}
.method-nav a:hover,.toc a:hover{color:var(--steel)}
.m-sec{padding:0 0 40px;margin-bottom:40px;border-bottom:1px solid var(--rule-2);counter-increment:sec}
.m-sec:last-child{border-bottom:0}
.m-sec h2,.article section h2{font:800 clamp(28px,2.6vw,38px)/1 var(--sans);font-stretch:70%;margin:0 0 20px;display:flex;align-items:baseline;gap:14px}
.m-sec h2::before,.article section h2::before{content:counter(sec);font:700 .5em/1 var(--sans);font-stretch:87%;color:var(--paper);background:var(--ink);min-width:1.6em;height:1.6em;display:inline-grid;place-items:center;flex:none;transform:translateY(-.2em)}
.continue h2::before{content:"→"}
.method-body p,.method-body li{font:400 18px/1.6 var(--serif);color:var(--ink)}
.steps{list-style:none;padding:0;margin:0;counter-reset:st}
.steps li{counter-increment:st;display:grid;grid-template-columns:52px 1fr;gap:0 10px;padding:14px 0;border-top:1px solid var(--rule)}
.steps li::before{content:counter(st);font:800 36px/.9 var(--sans);font-stretch:62%;color:var(--steel)}
.formula{margin:0 0 22px;padding:20px 0 16px;border-top:2px solid var(--ink);border-bottom:1px solid var(--ink)}
.formula .eq{display:flex;align-items:baseline;gap:12px;padding:7px 0;font:400 20px/1.4 var(--serif);flex-wrap:wrap}
.formula .lhs{font-style:italic;color:var(--ink)}
.formula .op{color:var(--amber-ink);font-family:var(--sans)}
.formula .rhs{color:var(--ink-2)}
.formula .eq-n{margin-left:auto;font:500 13px var(--sans);color:var(--graphite)}
.m-defs{color:var(--ink-2)}
.method-body :is(.lim-h,.example-tag),.article :is(.example-tag){font:600 11px/1.3 var(--sans);font-stretch:112%;letter-spacing:.09em;text-transform:uppercase}
.example{border-left:4px solid var(--amber);background:var(--sheet);padding:20px 24px}
.example-tag{color:var(--amber-ink);margin:0 0 10px}
.example p:last-child{margin-bottom:0}
.lim-grid{display:grid;grid-template-columns:1fr 1fr;gap:28px;margin-bottom:16px}
.lim-h{color:var(--ink);margin:0 0 10px;padding-bottom:8px;border-bottom:2px solid var(--ink)}
.assume{list-style:none;padding:0;margin:0}
.assume li{padding:10px 0;border-bottom:1px solid var(--rule);font-size:17px!important}
.limit-box{background:var(--night);color:var(--chalk);padding:18px 20px 6px;position:relative}
.limit-box .lim-h{color:var(--chalk);border-bottom-color:var(--chalk-2)}
.method-body .limit-box p{color:var(--chalk);font-size:16px}
.qa{padding:18px 0 4px;border-top:1px solid var(--rule)}
.qa h3{font:700 19px/1.25 var(--sans);font-stretch:87%;margin-bottom:8px}
.related-list{list-style:none;margin:0;padding:0;display:grid;grid-template-columns:repeat(auto-fit,minmax(220px,1fr));border-top:2px solid var(--ink)}
.related-list li+li{border-left:1px solid var(--rule-2)}
.related-list a{display:flex;flex-direction:column;gap:6px;padding:16px 18px 18px;text-decoration:none;color:var(--ink);height:100%}
.related-list li:first-child a{padding-left:0}
.rl-k{font:600 10.5px/1.3 var(--sans);font-stretch:112%;letter-spacing:.09em;text-transform:uppercase;color:var(--graphite)}
.rl-t{font:750 21px/1.1 var(--sans);font-stretch:80%}
.rl-o{font:italic 400 15px/1.3 var(--serif)!important;color:var(--steel)!important}
.related-list a:hover .rl-t{text-decoration:underline;text-decoration-color:var(--amber);text-decoration-thickness:3px;text-underline-offset:4px}

/* ==========================================================================
   REFERENCE & INFORMATION PAGES
   ========================================================================== */
.article-head{display:grid;grid-template-columns:1fr;gap:0 32px;padding:26px 0 34px;border-bottom:2px solid var(--ink);margin-bottom:40px}
.article-head.is-ref{grid-template-columns:auto 1fr;align-items:end}
.sheet-no{font:800 clamp(96px,13vw,190px)/.76 var(--sans);font-stretch:62%;color:var(--steel);letter-spacing:-.02em}
.article-head h1{font:800 clamp(40px,5.4vw,78px)/.9 var(--sans);font-stretch:62%;margin:0 0 16px;max-width:13em}
.article-head .deck{margin:0}
.article-layout{display:grid;grid-template-columns:230px minmax(0,760px);gap:clamp(28px,5vw,88px);margin-bottom:clamp(64px,8vw,112px)}
.article-aside{align-self:start;position:sticky;top:24px;display:grid;gap:28px}
.aside-h{margin:0 0 8px;color:var(--ink)}
.aside-tools{list-style:none;margin:0;padding:0}
.aside-tools a{display:flex;flex-direction:column;padding:9px 0;border-top:1px solid var(--rule);text-decoration:none;color:var(--ink);font-weight:700;font-stretch:87%;font-size:16px}
.at-g{font:italic 400 13px var(--serif);color:var(--graphite)}
.aside-tools a:hover{color:var(--steel)}
.article{counter-reset:sec;min-width:0}
.article section{counter-increment:sec;padding:0 0 30px;margin-bottom:34px;border-bottom:1px solid var(--rule-2)}
.article section:last-child{border-bottom:0}
.article p,.article li{font:400 18.5px/1.62 var(--serif);color:var(--ink)}
.article ul{padding-left:22px}
.article li{margin-bottom:6px}
.article table{border-collapse:collapse;width:100%;margin:6px 0 24px}
.article th{font:600 11px/1.3 var(--sans);font-stretch:112%;letter-spacing:.09em;text-transform:uppercase;color:var(--ink);text-align:left;padding:0 16px 10px 0;border-bottom:2px solid var(--ink)}
.article td{text-align:left;vertical-align:top;padding:12px 16px 12px 0;border-bottom:1px solid var(--rule);font:400 16.5px/1.5 var(--serif)}
.article td:first-child{font:700 17px/1.3 var(--sans);font-stretch:80%;white-space:nowrap;padding-right:28px;width:1%}
.article .example{margin:4px 0 24px}
.article .example p{font-size:17.5px}
.plate{margin:6px 0 28px;background:var(--sheet);border-top:2px solid var(--ink)}
.plate-art{padding:18px 14px 8px}
.plate-art .dg{max-height:400px}
.plate figcaption{display:flex;gap:14px;align-items:baseline;border-top:1px solid var(--rule);padding:12px 16px;font:italic 400 15.5px/1.5 var(--serif);color:var(--ink-2)}
.plate-no{font:700 13px/1.4 var(--sans);font-style:normal;font-stretch:87%;color:var(--steel);white-space:nowrap}
.k-info .article-head{grid-template-columns:1fr}
.nf-page{padding-top:40px;padding-bottom:100px;max-width:900px;margin-left:0}
.nf-page h1{font:800 clamp(44px,6vw,88px)/.9 var(--sans);font-stretch:62%;margin:0 0 20px}
.nf-page .dg{margin:10px 0 26px;max-width:520px}

/* ==========================================================================
   FOOTER
   ========================================================================== */
.site-footer{background:var(--night);color:var(--chalk);clip-path:polygon(0 36px,100% 0,100% 100%,0 100%);padding-top:36px;margin-top:0}
.site-footer a{color:var(--chalk)}
.site-footer :focus-visible{outline-color:var(--amber)}
.ft-inner{max-width:var(--max);margin:auto;padding:48px var(--gutter) 30px;display:grid;grid-template-columns:minmax(0,3.2fr) minmax(0,6fr) minmax(0,2fr);gap:36px 48px;align-items:start}
.site-footer .brand{color:var(--chalk)}
.ft-state{font:400 17px/1.5 var(--serif);color:var(--chalk-2);margin:18px 0 0;max-width:22em}
.ft-state em{color:var(--chalk);font-style:italic}
.ft-cols{display:grid;grid-template-columns:repeat(4,minmax(0,1fr));gap:24px}
.ft-h{color:var(--amber-hi);margin:0 0 10px}
.ft-cols ul{list-style:none;margin:0;padding:0}
.ft-cols a{display:block;padding:5px 0;text-decoration:none;font-size:14.5px;line-height:1.35;color:var(--chalk)}
.ft-cols a:hover{text-decoration:underline;text-decoration-color:var(--amber)}
.ft-fan{justify-self:end}
.pitch-fan{width:200px;height:auto;overflow:visible}
.pf-base{stroke:var(--chalk-2);stroke-width:1}
.pf-major{stroke:var(--chalk);stroke-width:1.2}
.pf-minor{stroke:var(--night-line);stroke-width:1}
.pitch-fan text{font:600 10.5px var(--sans);font-stretch:87%;fill:var(--chalk-2)}
.ft-colophon{max-width:var(--max);margin:auto;padding:14px var(--gutter) 28px;display:flex;flex-wrap:wrap;gap:6px 28px;border-top:1px solid var(--night-line);font-size:12.5px;color:var(--chalk-2)}

/* ==========================================================================
   DRAWING SYSTEM
   Light by default; the instrument panels switch the variables to dark.
   object = --dg-obj · dimension = --dg-dim · the answer = --dg-ans
   ========================================================================== */
.dg{--dg-obj:var(--ink);--dg-dim:var(--steel);--dg-ans:#c77a0a;--dg-ans-t:var(--amber-ink);--dg-muted:var(--graphite);--dg-bg:var(--sheet);--dg-fill:#dfe6ee;--dg-poche:var(--ink);--dg-allow:#e0921c;--dg-allow-w:#fbe5c2;
  display:block;width:100%;height:auto;overflow:visible;font-family:var(--sans)}
.inst .dg,.inst-dark .dg{--dg-obj:var(--chalk);--dg-dim:var(--sky);--dg-ans:var(--amber);--dg-ans-t:var(--amber-hi);--dg-muted:var(--chalk-2);--dg-bg:var(--night);--dg-fill:#243748;--dg-poche:#8093a3;--dg-allow:var(--amber);--dg-allow-w:#3a3322}
.dg text{font-size:13.5px;font-stretch:87%;fill:var(--dg-dim);font-variant-numeric:tabular-nums}
.dg.compact text{font-size:16px}
.dg .sym{font:italic 400 1.2em var(--serif)}
.dg .val{font-weight:600}
.dg .dim-text{paint-order:stroke;stroke:var(--dg-bg);stroke-width:6px;stroke-linejoin:round}
.dg .dim path{stroke:var(--dg-dim);stroke-width:1;fill:none}
.dg .dim .ah,.dg .ah{fill:var(--dg-dim);stroke:none}
.dg .dim.answer path{stroke:var(--dg-ans);stroke-width:1.8}
.dg .dim.answer .ah{fill:var(--dg-ans)}
.dg .dim.answer text{fill:var(--dg-ans-t);font-weight:700}
.dg .ext{stroke:var(--dg-dim);stroke-width:.8;opacity:.45;fill:none}
.dg .ref{stroke:var(--dg-obj);stroke-width:3.6;stroke-linecap:round;fill:none}
.dg .obj{stroke:var(--dg-obj);stroke-width:1.8;fill:none}
.dg .obj.thin{stroke-width:1.2}
.dg .obj.ghost{opacity:.3;stroke-width:3}
.dg .poche{fill:var(--dg-poche)}
.dg .fill-sheet{fill:var(--dg-bg)}
.dg .hatch{stroke:var(--dg-obj);stroke-width:.6;opacity:.5;fill:none}
.dg .hatch.allow{stroke:var(--dg-allow);opacity:1}
.dg .hatch.faint{stroke:var(--dg-dim);opacity:.4}
.dg .guide{stroke:var(--dg-muted);stroke-width:1;stroke-dasharray:4 4;fill:none;opacity:.8}
.dg .guide.solid{stroke-dasharray:none;stroke-width:.9}
.dg .cl{stroke:var(--dg-muted);stroke-width:1;stroke-dasharray:18 4 3 4;fill:none}
.dg .node{fill:var(--dg-bg);stroke:var(--dg-obj);stroke-width:2}
.dg .node.soft{fill:var(--dg-muted);stroke:none}
.dg .note{font-size:10.5px;font-stretch:112%;letter-spacing:.1em;fill:var(--dg-muted);font-weight:600}
.dg.compact .note{font-size:12.5px}
.dg .strong{font-weight:700}
.dg .verm{fill:var(--dg-ans-t)}
.dg .faint{fill:var(--dg-muted)}
.dg .result-text{fill:var(--dg-obj)}
.dg .pitch-glyph path{stroke:var(--dg-dim);stroke-width:1.3;fill:none}
.dg .pitch-glyph.answer path{stroke:var(--dg-ans);stroke-width:2}
.dg .pitch-glyph.answer text{fill:var(--dg-ans-t);font-weight:700}
.dg .plan{fill:var(--dg-fill);fill-opacity:.55;stroke:var(--dg-dim);stroke-width:1.2;stroke-dasharray:6 4}
.dg .surface{fill:var(--dg-fill);stroke:var(--dg-obj);stroke-width:2.4;stroke-linejoin:round}
.dg .surface-lines{stroke:var(--dg-obj);opacity:.18;stroke-width:1}
.dg .tile.base{fill:var(--dg-fill);stroke:var(--dg-dim);stroke-width:1}
.dg .tile.empty{fill:none;stroke:var(--dg-muted);stroke-width:1;stroke-dasharray:2 2;opacity:.6}
.dg .tile.allow{fill:var(--dg-allow-w);stroke:var(--dg-allow);stroke-width:1}
.dg .ghosted{opacity:.45}.dg .faded{opacity:.35}
.dg .grid-fine{stroke:var(--dg-dim);opacity:.35;stroke-width:.6}
.dg .bar.measured{fill:var(--dg-fill);stroke:var(--dg-dim);stroke-width:1}
.dg .bar.allow{fill:var(--dg-allow-w);stroke:var(--dg-allow);stroke-width:1}
.dg .bar.excess{fill:none;stroke:var(--dg-obj);stroke-width:1}
.dg .tape{stroke:var(--dg-obj);stroke-width:1;fill:none}
.dg .tape-num{font-size:11px;fill:var(--dg-muted)}
.dg.compact .tape-num{font-size:12.5px}
.dg .tape-num.strong{font-size:14px;font-weight:700}
.dg.compact .tape-num.strong{font-size:16px}
.dg .dim-open{stroke:var(--dg-dim);stroke-width:1;stroke-dasharray:3 5;fill:none}
/* input ↔ drawing: focusing a field lights its dimension */
.dg [data-dim].hl path{stroke:var(--dg-ans)!important;stroke-width:2.2}
.dg [data-dim].hl .ah{fill:var(--dg-ans)}
.dg [data-dim].hl text{fill:var(--dg-ans-t);font-weight:700}
.dg [data-dim].hl rect{stroke:var(--dg-ans);stroke-width:2}
.dg .dim path,.dg [data-dim] rect{transition:stroke .15s,stroke-width .15s}

/* ==========================================================================
   RESPONSIVE
   ========================================================================== */
@media (min-width:1100px){.eqn{flex-wrap:nowrap}.term{flex:0 1 auto}}
@media (max-width:1240px){
  .tools-inline .ti-label{display:none}
  .tools-inline a{padding:0 8px;font-size:14px}
  .ti-ridge{width:26px;margin:0 4px}
  .hi-bottom{grid-template-columns:1fr}
  .hi-next{border-left:0;border-top:1px solid var(--night-line);flex-direction:row;flex-wrap:wrap;align-items:center;min-width:0}
  .hi-next a{flex:1;min-width:180px}
  .result-body{grid-template-columns:1fr;grid-template-rows:none}
  .schedules{grid-column:1;grid-row:auto;grid-template-columns:repeat(auto-fit,minmax(220px,1fr));column-gap:28px;margin-top:10px}
  .st-link strong{font-size:19px}
  .st-link{padding:0 8px}
}
@media (max-width:1080px){
  .tools-inline,.site-nav{display:none}
  .tools-menu{display:block}
  .mh-inner{position:relative}
  .hero{grid-template-columns:1fr}
  .hero-text{display:grid;grid-template-columns:minmax(0,1fr) minmax(0,1fr);gap:0 40px;align-items:end}
  .hero-eyebrow,.hero-h1{grid-column:1}
  .hero-dek{grid-column:2;grid-row:2}
  .flow{grid-column:1/-1}
  .hero-go{grid-column:1/-1}
  .bench{grid-template-columns:minmax(290px,360px) minmax(0,1fr)}
  .map-head,.chain-head,.refs-head{grid-template-columns:1fr}
  .ft-inner{grid-template-columns:1fr 1fr}
  .ft-cols{grid-column:1/-1;grid-row:2}
  .ft-fan{grid-row:1;grid-column:2}
}
@media (max-width:900px){
  .map-stage{--roof:0px}
  .map-roof,.st::before{display:none}
  .map-ridge{position:static;transform:none;justify-content:center;margin:0;padding:18px 0;border-top:1px solid var(--ink);border-bottom:1px solid var(--ink);grid-column:1/-1;order:3;background:transparent}
  .map-list{grid-template-columns:1fr;gap:0;counter-reset:none}
  .map-stage{display:flex;flex-direction:column}
  .st{padding:16px 0 16px 34px;border-top:1px solid var(--rule)}
  .st-node{left:6px;top:24px;margin:0}
  .st-1 .st-node,.st-2 .st-node,.st-3 .st-node{border-radius:50%}
  .st-link{text-align:left;padding:0}
  .st::after{content:"";position:absolute;left:12px;top:0;bottom:0;border-left:1.5px solid var(--ink);z-index:1}
  .st-1::after,.st-4::after{top:24px}
  .st-3::after,.st-6::after{bottom:auto;height:24px}
  .st-node{z-index:2}
  .tool-head{grid-template-columns:1fr}
  .th-side{align-items:flex-start}
  .th-map{align-items:flex-start}
  .th-pos{text-align:left}
  .method,.article-layout{grid-template-columns:1fr}
  .method-nav,.article-aside{position:static}
  .method-nav ol{display:grid;grid-template-columns:repeat(auto-fit,minmax(170px,1fr));column-gap:20px}
  .article-aside{grid-template-columns:repeat(auto-fit,minmax(230px,1fr))}
  .ref-list{grid-template-columns:1fr}
  .ref-list li+li{border-left:0;border-top:1px solid var(--rule-2)}
  .ref-item,.ref-list li:first-child .ref-item,.ref-list li:last-child .ref-item{padding:20px 0 24px;grid-template-columns:auto 1fr 200px}
  .ref-fig{grid-column:3;grid-row:1/4;height:110px;margin:0;border:0}
  .ref-no{grid-row:1/3}
  .scope{grid-template-columns:1fr}
  .scope-more{grid-column:1}
  .lim-grid{grid-template-columns:1fr}
}
@media (max-width:900px){
  /* the tool map becomes two groups, with F between them */
  .map-list{display:contents}
  .map-side{position:static;padding:4px 0 14px;flex-direction:row;align-items:baseline;gap:12px;text-align:left}
  .ms-g{order:0}.st-1{order:1}.st-2{order:2}.st-3{order:3}.map-ridge{order:4}.ms-m{order:5;padding-top:22px}.st-4{order:6}.st-5{order:7}.st-6{order:8}
}
@media (max-width:780px){
  .bench{grid-template-columns:1fr;gap:28px}
  .inst{margin-inline:calc(var(--gutter) * -1);padding:20px var(--gutter) 28px}
  .inst-head{padding-right:70px}
  .drawing .dg{max-height:none}
  .hero-text{display:block}
  .hero-inst{margin-inline:calc(var(--gutter) * -1)}
  .hi-art-wide{display:none}
  .hi-art-narrow{display:block}
  .hi-top{padding-left:110px}
  .article-head.is-ref{grid-template-columns:1fr}
  .sheet-no{font-size:88px;margin-bottom:12px}
  .eqn{flex-direction:column;gap:0;padding-top:8px}
  .term{display:grid;grid-template-columns:1fr auto;gap:2px 12px;padding:14px 0;border-bottom:1px solid var(--rule-2);width:100%}
  .tv{grid-column:2;grid-row:1/4;text-align:right;align-self:center;font-size:40px}
  .tl{margin-top:0}
  .tt{margin-top:4px}
  .opr{display:none}
  .ref-item,.ref-list li:first-child .ref-item,.ref-list li:last-child .ref-item{grid-template-columns:auto 1fr}
  .ref-fig{display:none}
  .scope-cols{grid-template-columns:1fr;gap:28px}
  .ft-inner{grid-template-columns:1fr}
  .ft-fan{display:none}
  .ft-cols{grid-template-columns:1fr 1fr;grid-row:auto}
}
@media (max-width:560px){
  .mh-inner{min-height:56px;gap:12px}
  .wordmark{font-size:24px}
  .mark{width:30px;height:18px}
  .tools-menu summary{font-size:14px;padding-left:10px}
  .setup{grid-template-columns:1fr}
  .hero-h1{font-size:clamp(44px,13.4vw,60px)}
  .hi-measure{padding:14px 16px 0}
  .hi-top{padding:14px 16px 0 96px;font-size:10px}
  .hi-calc,.hi-result,.hi-next{padding-left:16px;padding-right:16px}
  .chip{font-size:13px;padding:4px 8px}
  .result-number{font-size:clamp(56px,19vw,80px)}
  .result-number.is-long{font-size:clamp(44px,13vw,64px)}
  .result-number.is-xlong{font-size:clamp(34px,10vw,48px)}
  .schedules{grid-template-columns:1fr}
  .drawing-caption{flex-direction:column;gap:2px}
  .plate figcaption{flex-direction:column;gap:4px}
  .article td:first-child{white-space:normal;width:auto}
  .article p,.article li{font-size:17.5px}
  .article td{font-size:15.5px}
  .formula .eq{font-size:17.5px}
  .method-body p,.method-body li{font-size:17px}
  .measure-pair{gap:6px}
  .tool-head h1{font-size:clamp(42px,14vw,60px)}
  .th-step{flex-direction:column;gap:8px}
  .hero-dek{margin-bottom:20px;font-size:18px}
  .flow{margin-bottom:24px}
  .related-list li+li{border-left:0;border-top:1px solid var(--rule)}
  .related-list a,.related-list li:first-child a{padding:14px 0}
}
@media (max-width:420px){
  .flow li{font-size:14px}
  .flow .stage{margin-right:6px}
  .flow li+li::before{width:14px;margin:0 8px 0 6px}
}
@media (max-width:360px){
  .input-shell span{padding:0 8px 0 2px}
  .ft-cols{grid-template-columns:1fr}
  .hi-top{padding-left:84px}
}
@media (pointer:coarse){.tool-button{min-height:44px}}
@media (prefers-reduced-motion:reduce){
  html{scroll-behavior:auto}
  *,*::before,*::after{transition:none!important;animation:none!important}
}

/* ==========================================================================
   PRINT — a light worksheet, whatever the screen shows
   ========================================================================== */
@media print{
  @page{margin:14mm}
  *{-webkit-print-color-adjust:exact;print-color-adjust:exact}
  body{background:#fff;color:#000;font-size:10pt}
  .skip,.tools-inline,.site-nav,.tools-menu,.crumbs,.th-side,.method-nav,.actions,.local-note,.result-actions,.handoffs,.text-button,.secondary,.site-footer,.hero-go,.map,.refs,.scope,.chain,.article-aside,.continue,noscript,.inst-cut{display:none!important}
  .masthead{border-bottom:1.5pt solid #000}
  .mh-inner{min-height:0;padding:0 0 8pt}
  .wrap{max-width:none;padding:0}
  .tool-head{padding:8pt 0 10pt}
  .tool-head h1{font-size:28pt}
  .th-dek,.deck{font-size:11pt}
  .bench{display:block;margin:0 0 14pt}
  .worksheet{display:none}
  .inst,.inst-dark{background:#fff!important;color:#000;clip-path:none;border:1pt solid #000;padding:10pt 12pt}
  .inst *{color:#000!important}
  .inst .dg,.inst-dark .dg{--dg-obj:#000;--dg-dim:#1a4570;--dg-ans:#000;--dg-ans-t:#000;--dg-muted:#444;--dg-bg:#fff;--dg-fill:#e6e6e6;--dg-poche:#000;--dg-allow:#555;--dg-allow-w:#eee}
  .inst-head{padding-right:0;margin-bottom:10pt;border-color:#999}
  .result-body{display:block}
  .schedules{display:grid;grid-template-columns:1fr 1fr;gap:6pt 18pt;margin-top:8pt}
  .result-number{font-size:32pt;margin:4pt 0 8pt}
  .result-note{font-size:10pt}
  .calc-line{padding:5pt 0;margin-bottom:6pt}
  .result-flag,.calc-line,.schedule>div,.drawing{border-color:#999!important}
  .limits-note{background:#fff;border:1px solid #999}
  .limits-note::before{display:none}
  .drawing{break-inside:avoid;margin-top:10pt}
  .drawing .dg{max-height:62mm}
  .print-summary{display:block;grid-column:1/-1;font:9pt/1.45 var(--sans);white-space:pre-line;border:1px solid #999;padding:8pt;margin-bottom:10pt;column-count:2;column-gap:14pt}
  .method,.article-layout{display:block;margin:14pt 0 0}
  .m-sec,.article section{padding-bottom:10pt;margin-bottom:10pt}
  .m-sec h2,.article section h2{font-size:16pt}
  .method-body p,.method-body li,.article p,.article li{font-size:10.5pt}
  .limit-box{background:#fff;color:#000;border:1px solid #000}
  .method-body .limit-box p,.limit-box .lim-h{color:#000}
  .scope-note,.schedule>div,.qa,.plate,.example,.formula,.limit-box,.steps li{break-inside:avoid}
  .hero{display:block}
  a{color:#000}
}