/* Machining Charts. Steel ground, graphite ink, white panels; one accent marks the hole zone and the answer. */
@font-face{font-family:'Big Shoulders Display';font-style:normal;font-weight:700 900;font-display:swap;src:url(/fonts/big-shoulders-display-latin.woff2) format('woff2')}
@font-face{font-family:'Public Sans';font-style:normal;font-weight:400 700;font-display:swap;src:url(/fonts/public-sans-latin.woff2) format('woff2')}
:root{color-scheme:light;--ground:#e6e9ec;--ink:#14181c;--ink-2:#47505a;--line:#bcc4ca;--paper:#fff;--accent:#2f5bea;--on-accent:#fff;--panel:#1b3a9e;--panel-text:#e8eeff;--panel-kicker:#b9c9ff;--hi:#fff;--bad:#b3261e;--bad-bg:#fdecea;--clear:#7ee2a8;--trans:#ffd166;--inter:#ffa38f;--clear-d:#1f8a4c;--trans-d:#b07800;--inter-d:#d4472b;--r-s:4px;--r-m:8px;--r-l:14px;
--display:'Big Shoulders Display',Impact,'Arial Narrow',sans-serif;--body:'Public Sans',system-ui,-apple-system,'Segoe UI',Roboto,sans-serif;--ease:cubic-bezier(.23,1,.32,1)}
*{box-sizing:border-box}
body{margin:0;background:var(--ground);color:var(--ink);font:400 1.0625rem/1.6 var(--body);-webkit-font-smoothing:antialiased}
a{color:var(--ink);text-decoration-color:var(--accent);text-decoration-thickness:2px;text-underline-offset:3px}
:focus-visible{outline:3px solid var(--accent);outline-offset:2px}
.wrap{max-width:72rem;margin:0 auto;padding-left:max(1rem,env(safe-area-inset-left));padding-right:max(1rem,env(safe-area-inset-right))}
.skip{position:absolute;left:-999px;top:0;background:var(--ink);color:#fff;padding:.6rem 1rem;z-index:10}
.skip:focus{left:0}
h1,h2,h3{text-wrap:balance}
h1{font:900 clamp(2.6rem,6vw,4.6rem)/.92 var(--display);margin:0 0 1rem}
h2{font:900 clamp(1.8rem,3vw,2.3rem)/1.05 var(--display);margin:3rem 0 .75rem;padding-top:.7rem;border-top:3px solid var(--ink)}
h3{font:800 1.4rem/1.15 var(--display);margin:1.75rem 0 .3rem}
main p,main li{max-width:46rem}
main>h1:first-child{margin-top:2rem}
main{padding-bottom:3rem}

.site-header{border-bottom:3px solid var(--ink)}
.site-header .wrap{display:flex;align-items:center;padding-top:.9rem;padding-bottom:.9rem}
.brand{display:flex;align-items:center;gap:.6rem;text-decoration:none;color:var(--ink);font:800 1.6rem/1 var(--display)}

/* hero */
.hero{display:grid;grid-template-columns:minmax(0,5fr) minmax(0,7fr);gap:2.5rem;padding:2rem 0 1rem;align-items:start}
.lede{font-size:1.15rem;color:var(--ink-2);margin:0 0 1.5rem}
.facts{list-style:none;margin:0;padding:0;display:grid;gap:1rem}
.facts li{border-top:2px solid var(--ink);padding-top:.6rem;color:var(--ink-2);font-size:.98rem}
.facts b{display:block;color:var(--ink);font:800 1.35rem/1.1 var(--display);margin-bottom:.1rem}

/* calculator */
.calc{background:var(--paper);border:3px solid var(--ink);border-radius:var(--r-l);padding:1.25rem;display:grid;gap:1rem;min-width:0}
.row{display:grid;grid-template-columns:1fr 1fr;gap:.75rem;align-items:start}
.row:first-child{grid-template-columns:2fr 1fr}
.field{display:grid;gap:.3rem;min-width:0}
.field span{font-weight:700;font-size:.9rem}
.field input,.field select{width:100%;font:800 1.9rem/1.1 var(--display);padding:.45rem .7rem;border:2px solid var(--ink);border-radius:var(--r-s);background:#fff;color:var(--ink);min-height:3.25rem;transition:border-color 150ms ease,background-color 150ms ease,color 150ms ease}
.field select{font:700 1.1rem var(--body)}
.field small,.hint{font-size:.85rem;color:var(--ink-2);transition:color 150ms ease}
fieldset.field{border:0;margin:0;padding:0;min-width:0}
.field legend{font-weight:700;font-size:.9rem;padding:0;margin-bottom:.3rem}
.pair{display:grid;grid-template-columns:1fr 1fr;gap:.35rem}
.field.cls select{font:800 1.6rem/1.1 var(--display);padding:.45rem .4rem;min-height:3.25rem}
.field.cls select:disabled{opacity:.45}
.hint{margin:-.4rem 0 0}
.field input::placeholder{color:var(--ink-2);font-weight:600}
.chips{display:flex;flex-wrap:wrap;gap:.4rem}
button{font:700 1rem var(--body);padding:.55rem 1rem;border:2px solid var(--ink);background:var(--ink);color:#fff;border-radius:var(--r-s);cursor:pointer;min-height:2.75rem;touch-action:manipulation;transition:transform 140ms var(--ease),background-color 120ms ease,color 120ms ease}
button:active{transform:scale(.97)}
.chip,.ghost{background:#fff;color:var(--ink)}
.result{display:grid;gap:.75rem;align-content:start;min-height:18rem}
.answer{background:var(--panel);color:var(--panel-text);border-radius:var(--r-m);padding:1rem 1.1rem}
.answer .kicker{display:block;font-size:.9rem;font-weight:700;color:var(--panel-kicker)}
.answer strong{display:block;font:900 clamp(2.4rem,6vw,3.4rem)/1 var(--display);color:var(--hi);margin:.15rem 0 .3rem}
/* fit type: light tints on the blue panel, darker dots on white */
.answer[data-fit=clearance] strong{color:var(--clear)}
.answer[data-fit=transition] strong{color:var(--trans)}
.answer[data-fit=interference] strong{color:var(--inter)}
.dot{display:inline-block;width:.7rem;height:.7rem;border-radius:50%;margin-right:.45rem}
.sr{position:absolute;width:1px;height:1px;overflow:hidden;clip:rect(0 0 0 0)}
.dot.clearance{background:var(--clear-d)}.dot.transition{background:var(--trans-d)}.dot.interference{background:var(--inter-d)}
.actions{display:flex;flex-wrap:wrap;align-items:center;gap:.5rem}
.status{font-weight:600;color:var(--ink-2)}
.note{font-size:.9rem;color:var(--ink-2);margin:0}
.note.warn{color:var(--bad);font-weight:700;border-left:4px solid var(--bad);background:var(--bad-bg);padding:.55rem .7rem}
/* inputs the calculator can't use: red border, red tint, red reason in the hint */
.field [aria-invalid=true]{border-color:var(--bad);background:var(--bad-bg);color:var(--bad)}
.field small.bad{color:var(--bad);font-weight:700}

/* zone diagram */
.zones{display:block;width:100%;max-width:26rem;height:14rem;font:600 12px var(--body);fill:var(--ink)}
.zones .zero{stroke:var(--ink);stroke-width:1.5;stroke-dasharray:4 3}
.zones .zh{fill:var(--accent)}
.zones .zs{fill:var(--paper);stroke:var(--ink);stroke-width:2}
.zones .zh+text+text+.zl{fill:var(--on-accent)}
.zones .zl{font:800 15px var(--display)}
.zones .zt{fill:var(--ink-2)}

/* tables */
.table-wrap{overflow-x:auto;background:var(--paper);border:2px solid var(--ink);border-radius:var(--r-m);margin:.9rem 0}
table{border-collapse:collapse;width:100%;font-size:.95rem;font-variant-numeric:tabular-nums}
caption{text-align:left;font-size:.85rem;color:var(--ink-2);padding:.5rem .75rem;caption-side:bottom;border-top:1px solid var(--line)}
th,td{padding:.5rem .7rem;text-align:left;vertical-align:top;border-bottom:1px solid var(--line)}
thead th{background:var(--ink);color:#fff;font-size:.85rem}
tbody th{font-weight:700;white-space:nowrap}
tbody tr:last-child>*{border-bottom:0}
td.num{white-space:nowrap}
.calc .table-wrap{margin:0}
/* single-zone size lookup (zone pages) */
.lookup{max-width:30rem;margin:1.5rem 0 0}

/* steps, lists, cite */
ol.steps{list-style:none;counter-reset:s;padding:0;margin:.75rem 0;display:grid;gap:.5rem}
ol.steps li{counter-increment:s;position:relative;padding:.7rem .9rem .7rem 3.2rem;background:var(--paper);border:2px solid var(--ink);border-radius:var(--r-m)}
ol.steps li::before{content:counter(s);position:absolute;left:.85rem;top:.75rem;width:1.6rem;height:1.6rem;border-radius:50%;background:var(--ink);color:#fff;font-weight:700;display:grid;place-items:center;font-size:.9rem}
ul.plain{padding-left:1.2rem}
ul.plain li{margin:.4rem 0}
.cite{margin-top:3rem;font-size:.92rem;color:var(--ink-2)}
.cite h2{font-size:1.4rem;margin-top:0}

.site-footer{background:var(--ink);color:#d9dee3;padding:1.5rem 0;font-size:.9rem}
.site-footer p{margin:.3rem 0;max-width:46rem}
.site-footer a{color:#fff}

@media (hover:hover){.chip:hover,.ghost:hover{background:var(--ink);color:#fff}}
/* one column: heading, then the calculator, then the intro and facts (the HTML order stays intro-first for search) */
@media (max-width:900px){.hero{grid-template-columns:minmax(0,1fr);gap:1rem;padding-top:1rem}
  .hero>div{display:contents}.hero h1{order:1;margin:0}.hero .calc{order:2}.lede{order:3;margin:.5rem 0 0}.facts{order:4}}
@media (max-width:40rem){.pref th:nth-child(2),.pref td:nth-child(2){display:none}table{font-size:.88rem}th,td{padding:.45rem .5rem}}
/* phones: inputs and the answer fit on the first screen */
@media (max-width:36rem){
  .site-header .wrap{padding-top:.6rem;padding-bottom:.6rem}
  .hero h1{font-size:2.3rem}
  .calc{padding:.85rem;gap:.7rem;border-width:2px}
  .row{gap:.5rem}
  .field{gap:.15rem}
  .field input,.field select{min-height:2.75rem;padding:.3rem .55rem}
  .field input{font-size:1.5rem}
  .field.cls select{font-size:1.3rem;min-height:2.75rem;padding:.3rem .35rem}
  .field small,.hint{font-size:.78rem}
  .hint{margin-top:-.25rem}
  .chips{flex-wrap:nowrap;overflow-x:auto;scrollbar-width:none;margin:0 -.85rem;padding:0 .85rem}
  .chips::-webkit-scrollbar{display:none}
  .chip{flex:none;min-height:2.5rem;padding:.4rem .75rem}
  .answer{padding:.75rem .9rem}
  .answer strong{font-size:2.2rem}
  /* narrow tables: let row labels wrap, tighten cells */
  table{font-size:.8rem}th,td{padding:.4rem .35rem}tbody th{white-space:normal}
}
/* reduced motion: keep colour fades, drop movement */
@media (prefers-reduced-motion:reduce){button:active{transform:none}html{scroll-behavior:auto}}

/* print: the result and tables, no controls */
@media print{
  body{background:#fff;font-size:10.5pt}
  .site-header,.site-footer,.chips,.actions,.skip,.row{display:none}
  .calc,.table-wrap{border:1px solid #000}
  .answer{background:none;color:#000;border:1px solid #000}
  .answer strong,.answer .kicker{color:#000}
  thead th{background:#ddd;color:#000}
  .hero{grid-template-columns:1fr}
  .lookup .field{display:none}
}