:root{
  --bg:#16130f; --bg2:#1d1914; --panel:#221d17; --line:#3a3127; --line2:#2c251e;
  --text:#ece6dc; --muted:#a89c8b; --ply:#d9a95b; --ply2:#b98a42; --blue:#7fb2dc; --red:#e57a63; --ok:#9bbf72;
  --paper:#f7f3ea; --ink:#2a2620;
  --sans:"Inter",system-ui,-apple-system,"Segoe UI",Roboto,Helvetica,Arial,sans-serif;
  --mono:"IBM Plex Mono",ui-monospace,SFMono-Regular,Menlo,Consolas,monospace;
  --r:12px;
}
*{box-sizing:border-box}
html{-webkit-text-size-adjust:100%}
body{margin:0;background:var(--bg);color:var(--text);font:15px/1.55 var(--sans);
  background-image:radial-gradient(circle at 20% -10%,rgba(217,169,91,.10),transparent 45%),
  linear-gradient(rgba(255,255,255,.018) 1px,transparent 1px),linear-gradient(90deg,rgba(255,255,255,.018) 1px,transparent 1px);
  background-size:auto,28px 28px,28px 28px}
a{color:var(--ply)}
h2{font-size:1rem;letter-spacing:.02em;margin:0 0 .75rem;font-weight:650}
code{font-family:var(--mono);font-size:.9em;background:rgba(255,255,255,.06);padding:0 .3em;border-radius:4px}
.wrap{max-width:1360px;margin:0 auto;padding:0 16px}
.top{position:sticky;top:0;z-index:20;background:rgba(22,19,15,.92);backdrop-filter:blur(8px);border-bottom:1px solid var(--line2)}
.bar{display:flex;align-items:center;justify-content:space-between;gap:12px;height:58px}
.brand{display:flex;align-items:center;gap:10px;color:var(--text);text-decoration:none}
.brand b{display:block;font-size:1.02rem;line-height:1.1}
.brand small{display:block;color:var(--muted);font-size:.72rem;letter-spacing:.14em;text-transform:uppercase}
.mark svg{width:30px;height:30px;display:block}
.mark rect{fill:var(--ply)}.mark rect:nth-child(n+3){fill:var(--text)}
.actions{display:flex;gap:8px}
.btn{appearance:none;border:1px solid var(--ply2);background:var(--ply);color:#1b150d;font:600 .9rem var(--sans);padding:.55rem .9rem;border-radius:9px;cursor:pointer;min-height:40px}
.btn:hover{filter:brightness(1.07)}
.btn.ghost{background:transparent;color:var(--ply);border-color:var(--line)}
.btn.small{min-height:32px;padding:.3rem .7rem;font-size:.82rem}
.layout{display:grid;grid-template-columns:370px minmax(0,1fr);gap:18px;padding-top:18px;padding-bottom:30px;align-items:start}
.inputs,.results{min-width:0}
.panel{background:var(--panel);border:1px solid var(--line2);border-radius:var(--r);padding:16px;margin-bottom:16px;box-shadow:0 1px 0 rgba(255,255,255,.03) inset}
.inputs{position:sticky;top:76px;max-height:calc(100vh - 92px);overflow:auto;scrollbar-width:thin}
.grp{border-bottom:1px dashed var(--line);padding-bottom:14px;margin-bottom:14px}
.grp:last-of-type{border-bottom:0}
.grp-h{display:flex;justify-content:space-between;align-items:center;gap:8px;margin-bottom:.6rem}
.grp-h h2{margin:0}
label{display:block;font-size:.8rem;color:var(--muted);margin-bottom:8px}
.lbl{display:block;font-size:.8rem;color:var(--muted);margin-bottom:4px}
input,select{display:block;width:100%;margin-top:3px;background:#15110d;border:1px solid var(--line);color:var(--text);border-radius:8px;padding:.5rem .6rem;font:500 .95rem var(--mono);min-height:40px}
select{font-family:var(--sans)}
input:focus,select:focus{outline:2px solid var(--ply);outline-offset:0;border-color:transparent}
input.bad{border-color:var(--red)}
.row2,.row3{display:grid;gap:8px}.row2{grid-template-columns:1fr 1fr}.row3{grid-template-columns:1fr 1fr 1fr}
.full{margin-bottom:8px}
.hint{color:var(--muted);font-size:.78rem;margin:.1rem 0 .6rem}
.verify{font-size:.78rem;color:#f0c987;background:rgba(217,169,91,.1);border:1px solid rgba(217,169,91,.3);border-radius:8px;padding:.4rem .55rem;margin:.2rem 0 .7rem}
.seg{display:inline-flex;border:1px solid var(--line);border-radius:9px;overflow:hidden}
.seg.wide{display:flex;width:100%;margin-bottom:10px}
.seg button{flex:1;appearance:none;border:0;background:transparent;color:var(--muted);font:600 .8rem var(--sans);padding:.5rem .55rem;cursor:pointer;min-height:38px}
.seg button+button{border-left:1px solid var(--line)}
.seg button.on{background:var(--ply);color:#1b150d}
.checks{display:flex;flex-wrap:wrap;gap:6px 14px;margin-bottom:8px}
.chk{display:flex;align-items:center;gap:7px;color:var(--text);font-size:.88rem;margin:0}
.chk input{width:18px;height:18px;min-height:0;margin:0;accent-color:var(--ply)}
.switch{position:relative;display:inline-block;width:46px;height:26px;margin:0}
.switch input{opacity:0;width:0;height:0;position:absolute}
.switch span{position:absolute;inset:0;background:#3a3127;border-radius:20px;transition:.2s;cursor:pointer}
.switch span:before{content:"";position:absolute;width:20px;height:20px;left:3px;top:3px;background:var(--text);border-radius:50%;transition:.2s}
.switch input:checked+span{background:var(--ply)}.switch input:checked+span:before{transform:translateX(20px);background:#1b150d}
.sr{position:absolute;width:1px;height:1px;overflow:hidden;clip:rect(0 0 0 0)}
[hidden]{display:none!important}
.stats{display:grid;grid-template-columns:repeat(auto-fit,minmax(150px,1fr));gap:10px}
.stat{background:#1a1612;border:1px solid var(--line2);border-radius:10px;padding:10px 12px}
.stat .k{font-size:.72rem;color:var(--muted);text-transform:uppercase;letter-spacing:.08em}
.stat .v{font:600 1.15rem var(--mono);color:var(--text);margin-top:2px}
.stat .s{font-size:.75rem;color:var(--muted)}
.stat.hero{grid-column:1/-1;display:flex;flex-wrap:wrap;align-items:baseline;gap:6px 18px;background:linear-gradient(135deg,rgba(217,169,91,.16),rgba(217,169,91,.04));border-color:rgba(217,169,91,.35)}
.stat.hero .v{font-size:1.6rem;color:var(--ply)}
.alert{border-radius:10px;padding:.55rem .75rem;margin:0 0 8px;font-size:.88rem;border:1px solid}
.alert.err{background:rgba(229,122,99,.12);border-color:rgba(229,122,99,.5)}
.alert.warn{background:rgba(240,201,135,.1);border-color:rgba(240,201,135,.4)}
.alert.note{background:rgba(127,178,220,.08);border-color:rgba(127,178,220,.3)}
.draw{background:var(--paper);border-radius:10px;padding:8px;overflow:auto;-webkit-overflow-scrolling:touch}
.draw svg{display:block;width:100%;height:auto;max-height:78vh}
.two{display:grid;grid-template-columns:minmax(0,1fr) minmax(0,1fr);gap:16px}
.two .panel{margin-bottom:16px}
.h-row{display:flex;justify-content:space-between;align-items:center;margin-bottom:.6rem}.h-row h2{margin:0}
.tbl{width:100%;border-collapse:collapse;font-size:.86rem}
.tbl th{text-align:left;color:var(--muted);font-weight:600;font-size:.74rem;text-transform:uppercase;letter-spacing:.06em;border-bottom:1px solid var(--line);padding:6px 8px}
.tbl td{border-bottom:1px solid var(--line2);padding:7px 8px;vertical-align:top}
.tbl td.n{font-family:var(--mono);white-space:nowrap}
.tbl tfoot td{font-weight:700;border-bottom:0}
.tbl input{display:inline-block;width:86px;min-height:32px;padding:.25rem .4rem;margin:0}
.scroll{overflow-x:auto}
.sheets{display:grid;grid-template-columns:repeat(auto-fill,minmax(300px,1fr));gap:12px}
.sheet figcaption{font-size:.8rem;color:var(--muted);margin-top:4px}
.sheet .draw{padding:4px}
.steps{padding-left:1.2rem;margin:0 0 1rem}.steps li{margin-bottom:.55rem}
.btns{display:flex;flex-wrap:wrap;gap:8px;margin:.5rem 0}
.mods{display:flex;flex-wrap:wrap;gap:10px;align-items:center}
.pill{display:inline-block;background:#1a1612;border:1px solid var(--line);border-radius:999px;padding:.2rem .65rem;font-size:.8rem;font-family:var(--mono)}
.mini{display:none}
.foot{border-top:1px solid var(--line2);color:var(--muted);font-size:.82rem;padding:18px 0 40px}
.foot .by a{color:var(--ply);font-weight:600;text-decoration:none;letter-spacing:.04em}
.toast{position:fixed;left:50%;bottom:24px;transform:translateX(-50%) translateY(30px);opacity:0;background:var(--text);color:#1b150d;padding:.55rem .9rem;border-radius:9px;font-weight:600;transition:.25s;z-index:50;pointer-events:none}
.toast.show{opacity:1;transform:translateX(-50%)}
.print-only{display:none}
@media (max-width:1000px){
  .layout{grid-template-columns:minmax(0,1fr)}
  .inputs{position:static;max-height:none}
  .two{grid-template-columns:1fr}
  .mini{display:flex;position:sticky;top:58px;z-index:15;gap:10px;justify-content:space-between;align-items:center;background:#2a2219;border-bottom:1px solid var(--line);padding:6px 16px;font:600 .82rem var(--mono)}
  .mini a{color:var(--ply);font-family:var(--sans)}
}
@media (max-width:420px){
  .row3{grid-template-columns:1fr 1fr}
  .brand small{display:none}
  .btn{padding:.4rem .6rem;font-size:.8rem}
  .seg button{font-size:.74rem;padding:.45rem .35rem}
}
@media print{
  @page{margin:12mm}
  body{background:#fff;color:#111;font-size:11pt}
  .no-print,.top,.mini,.toast{display:none!important}
  .print-only{display:block}
  .layout{display:block;padding:0}
  .panel{background:#fff;border:1px solid #bbb;box-shadow:none;break-inside:avoid;page-break-inside:avoid;padding:10px;margin-bottom:10px}
  .stat,.alert{background:#fff!important;border-color:#bbb!important;color:#111}
  .stat .v,.stat.hero .v{color:#111}
  .stat .k,.stat .s,.hint,.tbl th,.foot{color:#444}
  .tbl td{border-color:#ddd}
  .draw{background:#fff;padding:0}
  .two{display:block}
  #drawings{border:0;padding:0;break-inside:auto;page-break-inside:auto}
  #drawings>.h-row{display:none}
  .vpane,.vpane[hidden]{display:block!important;break-inside:avoid;page-break-inside:avoid;border:1px solid #bbb;border-radius:0;padding:8px;margin:0 0 10px}
  .vcap{color:#111}.vcap .vscale{color:#444}
  .vpane .draw svg{max-height:7.4in;width:auto;max-width:100%;margin:0 auto}
  #v-rail svg,#v-top svg{max-height:4.2in}
  a{color:#111}
  .print-head h1{font-size:16pt;margin:0 0 4px}
  .print-head p{margin:0 0 8px;font-size:9.5pt}
  .tbl input{border:0;background:transparent;color:#111;width:auto;padding:0;font-family:var(--mono)}
}
.casters,.ladder,.framebox{display:block;margin-top:4px;margin-bottom:10px;padding:10px;border:1px dashed var(--line);border-radius:10px}
.casters .row2,.ladder .row2,.framebox .row2{margin-bottom:8px}
b.ok{color:#4caf72} b.bad{color:#e0533d}
@media print{b.ok{color:#1d6b3a} b.bad{color:#a52a1a}}

/* drawings */
.vtabs{display:flex;flex-wrap:wrap;width:100%;margin-bottom:10px}
.vtabs button{flex:1 1 auto}
.vtabs button[aria-selected="true"]{background:var(--ply);color:#1b150d}
.vpane{margin:0 0 12px}
.vcap{display:flex;flex-wrap:wrap;align-items:center;gap:4px 12px;margin:0 0 6px;font-size:.88rem}
.vcap .vscale{color:var(--muted);font-size:.74rem;flex:1 1 220px}
.vbtns{display:inline-flex;gap:6px;flex-wrap:wrap}
.draw.zoomable{cursor:zoom-in}
#drawings .draw svg{max-height:72vh}
#drawings.all .vpane{border-top:1px dashed var(--line);padding-top:10px}
.viewer{position:fixed;inset:0;z-index:100;background:#120f0c;display:flex;flex-direction:column}
.viewer[hidden]{display:none}
.vbar{background:#120f0c;display:flex;flex-wrap:wrap;gap:6px 10px;align-items:center;justify-content:space-between;padding:8px 12px;border-bottom:1px solid var(--line);font-size:.85rem}
.vstage{flex:1;overflow:auto;-webkit-overflow-scrolling:touch;touch-action:pan-x pan-y pinch-zoom;background:var(--paper);display:flex;align-items:flex-start;justify-content:center}
.vstage svg{display:block;width:100%;height:auto;max-height:100%;flex:none;margin:auto}
body.noscroll{overflow:hidden}
@media (max-width:600px){.vtabs button{font-size:.72rem;padding:.45rem .3rem}.vcap .vbtns .btn{min-height:30px;font-size:.75rem}}
@media print{
  #drawings .vpane .draw svg{max-height:7.4in;width:auto;max-width:100%;margin:0 auto}
  #drawings #v-rail svg,#drawings #v-top svg,#drawings #v-iso svg{max-height:4.4in}
  #drawings.all .vpane{border-top:1px solid #bbb}
  .draw.zoomable{cursor:auto}
}
/* rail stock picker */
#railStockInfo{margin:4px 0 8px;line-height:1.45}
.badge{display:inline-block;padding:1px 7px;border-radius:999px;background:#e3f2e1;color:#1e6b2a;font-weight:700;font-size:.78rem;white-space:nowrap}
.badge.saw{background:#fbeee0;color:#8a4b12}
@media print{.badge{border:1px solid currentColor}}