/* Earthing System — interface styles */
:root{
  --bg:#eef2f5; --panel:#ffffff; --panel-2:#f7f9fb; --line:#d8e0e7;
  --ink:#1a2027; --ink-2:#4a5661; --ink-3:#5f6c78;
  --accent:#0f6b8a; --accent-2:#0d5a75; --accent-soft:#e3f0f5;
  --ok:#0b7a45; --ok-soft:#e3f6ec; --bad:#c0322b; --bad-soft:#fdecea;
  --warn:#8a5208; --warn-soft:#fdf3e2;
  --focus:#0f6b8a; --on-accent:#ffffff;
  --shadow:0 1px 2px rgba(16,32,48,.06),0 4px 14px rgba(16,32,48,.06);
  --r:9px; --mono:"JetBrains Mono","Cascadia Mono",Consolas,monospace;
}
[data-theme="dark"]{
  --bg:#12171c; --panel:#1a2128; --panel-2:#151b21; --line:#2a343d;
  --ink:#e6edf3; --ink-2:#a9b8c6; --ink-3:#8d9cab;
  --accent:#4bb6d8; --accent-2:#69c8e8; --accent-soft:#17323d;
  --ok:#4ed08a; --ok-soft:#12301f; --bad:#f18179; --bad-soft:#3a1a17;
  --warn:#e6b25e; --warn-soft:#33260f;
  --focus:#69c8e8; --on-accent:#0b1a22;
  --shadow:0 1px 2px rgba(0,0,0,.4),0 4px 16px rgba(0,0,0,.3);
}
*{box-sizing:border-box}
html,body{height:100%}
body{margin:0;background:var(--bg);color:var(--ink);
  font:14px/1.5 "Segoe UI",Inter,system-ui,-apple-system,sans-serif;}
a{color:var(--accent)}
h1,h2,h3,h4{margin:0}

/* ---------- shell ---------- */
#app{display:grid;grid-template-columns:246px 1fr;grid-template-rows:auto 1fr;
  grid-template-areas:"brand top" "nav main";height:100vh}
#brand{grid-area:brand;background:var(--accent);color:var(--on-accent);display:flex;
  align-items:center;gap:10px;padding:0 16px;height:56px}
#brand .logo{width:26px;height:26px;flex:0 0 26px}
#brand b{font-size:16px;letter-spacing:.2px}
#brand span{font-size:12px;opacity:.92;margin-inline-start:auto}
#top{grid-area:top;background:var(--panel);border-bottom:1px solid var(--line);
  height:56px;display:flex;align-items:center;gap:10px;padding:0 16px}
#top .grow{flex:1}
#nav{grid-area:nav;background:var(--panel);border-inline-end:1px solid var(--line);
  overflow-y:auto;padding:10px 8px}
#main{grid-area:main;overflow-y:auto;padding:18px 22px 60px}

/* ---------- nav ---------- */
.navgroup{font-size:12px;text-transform:uppercase;letter-spacing:.9px;
  color:var(--ink-3);margin:14px 10px 6px;font-weight:700}
.navitem{display:flex;align-items:center;gap:9px;padding:8px 10px;border-radius:7px;
  cursor:pointer;color:var(--ink-2);font-size:13.5px;user-select:none}
.navitem:hover{background:var(--panel-2);color:var(--ink)}
.navitem.active{background:var(--accent-soft);color:var(--accent);font-weight:600}
.navitem .n{width:20px;height:20px;border-radius:5px;background:var(--panel-2);
  display:grid;place-items:center;font-size:12px;font-weight:700;color:var(--ink-3)}
.navitem.active .n{background:var(--accent);color:var(--on-accent)}
.navitem .dot{margin-inline-start:auto;width:7px;height:7px;border-radius:50%;background:transparent}
.navitem.done .dot{background:var(--ok)}
.navitem.failed .dot{background:var(--bad)}

/* ---------- controls ---------- */
button,.btn{font:inherit;border:1px solid var(--line);background:var(--panel);
  color:var(--ink);padding:7px 13px;border-radius:7px;cursor:pointer;
  display:inline-flex;align-items:center;gap:7px}
button:hover{border-color:var(--accent);color:var(--accent)}
button.primary{background:var(--accent);border-color:var(--accent);color:var(--on-accent);font-weight:600}
button.primary:hover{background:var(--accent-2);color:var(--on-accent)}
button.ghost{border-color:transparent;background:transparent}
button:disabled{opacity:.5;cursor:not-allowed}
input,select,textarea{font:inherit;color:var(--ink);background:var(--panel);
  border:1px solid var(--line);border-radius:6px;padding:6px 8px;width:100%}
input:focus,select:focus,textarea:focus{outline:none;border-color:var(--accent)}
input:focus-visible,select:focus-visible,textarea:focus-visible{outline:2px solid var(--focus);outline-offset:1px}
input[type=checkbox]{width:auto}
label{font-size:12.5px;color:var(--ink-2)}

/* ---------- layout ---------- */
.page{display:none}
.page.active{display:block;animation:fade .18s ease}
@keyframes fade{from{opacity:0;transform:translateY(4px)}to{opacity:1;transform:none}}
.pagehead{margin-bottom:14px}
.pagehead h2{font-size:19px;letter-spacing:-.2px}
.pagehead p{margin:4px 0 0;color:var(--ink-2);font-size:13px;max-width:80ch}
.sechead{font-size:16px;margin:26px 0 12px;padding-top:14px;border-top:1px solid var(--line)}
.cols{display:grid;gap:16px}
.cols.c2{grid-template-columns:minmax(320px,400px) 1fr}
.cols.c2e{grid-template-columns:1fr 1fr}
.cols.c3{grid-template-columns:repeat(3,1fr)}
@media(max-width:1100px){.cols.c2,.cols.c2e,.cols.c3{grid-template-columns:1fr}}

.card{background:var(--panel);border:1px solid var(--line);border-radius:var(--r);
  box-shadow:var(--shadow);margin-bottom:16px;overflow:hidden}
.card>h3{padding:11px 15px;border-bottom:1px solid var(--line);font-size:13.5px;
  background:var(--panel-2);display:flex;align-items:center;gap:8px}
.card>h3 .sub{font-weight:400;color:var(--ink-3);font-size:12px;margin-inline-start:auto}
.card .body{padding:14px 15px}
.card .body.tight{padding:8px 10px}

.field{display:grid;grid-template-columns:1fr 108px 42px;gap:8px;align-items:center;
  margin-bottom:8px}
.field .u{font-size:12px;color:var(--ink-3)}
.field.wide{grid-template-columns:1fr 158px}
.field.full{grid-template-columns:1fr}
.hint{font-size:12px;color:var(--ink-3);margin:-4px 0 10px}

/* ---------- field help ----------
   The explanation lives in the markup next to its input but stays out of the
   way: a small ? badge on the label calls it up on hover or on click, and
   "Explain all" in the top bar puts every one of them back inline. */
.field .fh{display:none;grid-column:1/-1;font-size:12px;line-height:1.45;
  color:var(--ink-3);margin:2px 0 4px;max-width:64ch}
body.helpall .field .fh{display:block}
body.helpall .qm{opacity:.6}

.qm{display:inline-flex;align-items:center;justify-content:center;width:14px;
  height:14px;margin-inline-start:5px;border-radius:50%;font-size:10px;
  font-weight:700;line-height:1;cursor:help;user-select:none;vertical-align:1px;
  color:var(--ink-3);background:transparent;border:1px solid var(--line);
  transition:color .12s,border-color .12s,background .12s}
.qm{position:relative;width:16px;height:16px;font-size:11px}
.qm::after{content:'';position:absolute;inset:-4px;border-radius:50%}
.qm:hover,.qm:focus-visible{color:var(--on-accent);background:var(--accent);border-color:var(--accent)}
.qm:focus-visible{outline:2px solid var(--focus);outline-offset:2px}

.pfield label i{font-style:normal;color:var(--ink-3)}
.pfield[data-help]{cursor:help}
.pfield[data-help] label{border-bottom:1px dotted var(--line)}
.pfield[data-help]:hover label{color:var(--accent);border-bottom-color:var(--accent)}

#btnHelp.on{background:var(--accent-soft);color:var(--accent);border-color:var(--accent)}

/* the floating explanation itself */
#fieldtip{position:fixed;z-index:80;max-width:330px;padding:9px 12px;
  border-radius:8px;background:var(--panel);color:var(--ink-2);
  border:1px solid var(--line);box-shadow:0 6px 24px rgba(16,32,48,.16);
  font-size:12.5px;line-height:1.5;pointer-events:none}
#fieldtip.pinned{pointer-events:auto}
[data-theme="dark"] #fieldtip{box-shadow:0 6px 24px rgba(0,0,0,.5)}
#fieldtip .ft-arrow{position:absolute;top:-5px;width:9px;height:9px;
  margin-inline-start:-4.5px;background:var(--panel);border-left:1px solid var(--line);
  border-top:1px solid var(--line);transform:rotate(45deg)}
#fieldtip.above .ft-arrow{top:auto;bottom:-5px;border-left:0;border-top:0;
  border-right:1px solid var(--line);border-bottom:1px solid var(--line)}
#fieldtip sub{font-size:.8em}
fieldset{border:1px solid var(--line);border-radius:7px;padding:10px 12px;margin:0 0 12px}
legend{font-size:12px;color:var(--ink-2);padding:0 5px;font-weight:600}

/* ---------- data display ---------- */
table.data{width:100%;border-collapse:collapse;font-size:12.8px}
table.data th,table.data td{border-bottom:1px solid var(--line);padding:6px 9px;text-align:left}
table.data th{color:var(--ink-2);font-weight:600;background:var(--panel-2);
  position:sticky;top:0}
table.data td.n{text-align:right;font-variant-numeric:tabular-nums;font-family:var(--mono);font-size:12px}
table.data tr:hover td{background:var(--panel-2)}
table.data input{padding:3px 6px;font-size:12.5px}
table.data td.sym{font-family:var(--mono);color:var(--accent);width:74px}
table.data td.src{color:var(--ink-3);font-size:12px}

.kpis{display:grid;grid-template-columns:repeat(auto-fit,minmax(140px,1fr));gap:10px;margin-bottom:14px}
.kpi{background:var(--panel);border:1px solid var(--line);border-radius:var(--r);
  padding:11px 13px;box-shadow:var(--shadow)}
.kpi .v{font-size:20px;font-weight:700;letter-spacing:-.4px;font-variant-numeric:tabular-nums}
.kpi .l{font-size:12px;color:var(--ink-2);margin-top:2px}
.kpi.ok .v{color:var(--ok)} .kpi.bad .v{color:var(--bad)}

.badge{display:inline-flex;align-items:center;gap:5px;padding:2px 9px;border-radius:20px;
  font-size:12px;font-weight:700}
.badge.ok{background:var(--ok-soft);color:var(--ok)}
.badge.bad{background:var(--bad-soft);color:var(--bad)}
.badge.warn{background:var(--warn-soft);color:var(--warn)}
.badge.info{background:var(--accent-soft);color:var(--accent)}

.formula{font-family:"Cambria Math",Georgia,serif;background:var(--panel-2);
  border-inline-start:3px solid var(--accent);padding:7px 11px;border-radius:0 6px 6px 0;
  font-size:13px;margin:9px 0;color:var(--ink-2);overflow-x:auto}
.note{background:var(--warn-soft);border:1px solid color-mix(in srgb,var(--warn) 30%,transparent);
  border-radius:7px;padding:9px 12px;font-size:12.5px;margin:10px 0;color:var(--ink)}
.note.info{background:var(--accent-soft);border-color:color-mix(in srgb,var(--accent) 30%,transparent)}
.plot{width:100%;height:340px}
.plot.tall{height:460px}
.empty{color:var(--ink-3);font-size:13px;padding:22px;text-align:center;
  border:1px dashed var(--line);border-radius:8px}
.rowbtns{display:flex;gap:8px;flex-wrap:wrap;margin-top:10px}
.tabs{display:flex;gap:2px;border-bottom:1px solid var(--line);margin-bottom:12px;flex-wrap:wrap}
.tab{padding:7px 13px;cursor:pointer;font-size:13px;color:var(--ink-2);
  border-bottom:2px solid transparent;user-select:none}
.tab:hover{color:var(--ink)}
.tab.active{color:var(--accent);border-bottom-color:var(--accent);font-weight:600}
.tabpane{display:none}.tabpane.active{display:block}
.chips{display:flex;gap:6px;flex-wrap:wrap;margin:6px 0 10px}
.chip{padding:3px 10px;border:1px solid var(--line);border-radius:20px;font-size:12px;
  cursor:pointer;color:var(--ink-2)}
.chip:hover{border-color:var(--accent);color:var(--accent)}
.chip.on{background:var(--accent);border-color:var(--accent);color:var(--on-accent)}

#toast{position:fixed;inset-inline-end:18px;bottom:18px;display:flex;flex-direction:column;
  gap:8px;z-index:99}
.toast{background:var(--panel);border:1px solid var(--line);border-inline-start:4px solid var(--accent);
  border-radius:8px;padding:10px 14px;box-shadow:var(--shadow);font-size:13px;max-width:380px;
  animation:slide .2s ease}
.toast.err{border-inline-start-color:var(--bad)}
.toast.ok{border-inline-start-color:var(--ok)}
@keyframes slide{from{opacity:0;transform:translateX(20px)}to{opacity:1;transform:none}}
.spinner{width:14px;height:14px;border:2px solid var(--line);border-top-color:var(--accent);
  border-radius:50%;animation:spin .7s linear infinite;display:inline-block}
@keyframes spin{to{transform:rotate(360deg)}}
.muted{color:var(--ink-3)}
.small{font-size:12px}
.mono{font-family:var(--mono)}
canvas.layout{width:100%;border:1px solid var(--line);border-radius:7px;background:var(--panel-2)}
#modal{position:fixed;inset:0;background:rgba(10,18,26,.55);display:none;place-items:center;z-index:100}
#modal.on{display:grid}
#modal .box{background:var(--panel);border-radius:12px;width:min(920px,92vw);
  max-height:88vh;overflow:auto;box-shadow:0 20px 60px rgba(0,0,0,.3)}
#modal .box header{padding:13px 18px;border-bottom:1px solid var(--line);
  display:flex;align-items:center;gap:10px;position:sticky;top:0;background:var(--panel)}
#modal .box .content{padding:16px 18px}

.pgrid{display:grid;grid-template-columns:repeat(auto-fill,minmax(104px,1fr));gap:5px 8px}
.pfield{display:flex;flex-direction:column;gap:2px}
.pfield label{font-size:12px;color:var(--ink-3);text-transform:none}
.pfield input{padding:3px 6px;font-size:12px}

/* ---------- verdict and reasoning ---------- */
.verdictbox{border-radius:8px;padding:12px 14px;margin-bottom:12px;border:1px solid}
.verdictbox.ok{background:var(--ok-soft);border-color:color-mix(in srgb,var(--ok) 32%,transparent)}
.verdictbox.bad{background:var(--bad-soft);border-color:color-mix(in srgb,var(--bad) 32%,transparent)}
.verdictbox p{margin:8px 0 0;font-size:13px;line-height:1.6}
table.data.checks tr.crow.has-why{cursor:pointer}
table.data.checks tr.crow.open td{background:var(--panel-2)}
.twist{display:inline-block;width:14px;color:var(--ink-3);font-size:11px}
.why{padding:4px 6px 10px 22px;font-size:12.6px;line-height:1.65;color:var(--ink-2)}
.why p{margin:7px 0}
.why .vsum{color:var(--ink)}
.why .mean{border-inline-start:2px solid var(--line);padding-inline-start:10px}
.why b{color:var(--ink)}
.why ol{margin:6px 0 0;padding-inline-start:20px}
.why li{margin:5px 0}

/* ---------- theory browser ---------- */
.theorywrap{display:grid;grid-template-columns:246px 1fr;gap:18px;align-items:start}
@media(max-width:1000px){.theorywrap{grid-template-columns:1fr}}
.toc{position:sticky;top:0;max-height:calc(100vh - 96px);overflow-y:auto;
  background:var(--panel);border:1px solid var(--line);border-radius:var(--r);padding:10px}
.toc a{display:block;padding:5px 9px;border-radius:6px;font-size:12.5px;color:var(--ink-2);
  text-decoration:none;line-height:1.35}
.toc a:hover{background:var(--panel-2);color:var(--ink)}
.toc a.on{background:var(--accent-soft);color:var(--accent);font-weight:600}
#theoryBody{padding:0}
.doc{padding:22px 30px;max-width:86ch;font-size:14px;line-height:1.72;color:var(--ink)}
.doc h1{font-size:23px;margin:0 0 6px}
.doc h2{font-size:18px;margin:34px 0 10px;padding-bottom:6px;border-bottom:2px solid var(--accent);
  scroll-margin-top:14px}
.doc h3{font-size:15px;margin:22px 0 7px;color:var(--accent)}
.doc h4{font-size:13.5px;margin:16px 0 5px}
.doc p{margin:11px 0}
.doc ul,.doc ol{margin:10px 0;padding-inline-start:24px}
.doc li{margin:5px 0}
.doc hr{border:0;border-top:1px solid var(--line);margin:26px 0}
.doc code{background:var(--panel-2);border:1px solid var(--line);border-radius:4px;
  padding:1px 5px;font-family:var(--mono);font-size:12.5px}
.doc pre.mdcode{background:var(--panel-2);border:1px solid var(--line);
  border-inline-start:3px solid var(--accent);border-radius:0 7px 7px 0;
  padding:11px 14px;overflow-x:auto;font-family:var(--mono);font-size:12.5px;line-height:1.6;
  white-space:pre;margin:12px 0}
.doc blockquote{margin:12px 0;padding:9px 14px;background:var(--warn-soft);
  border:1px solid color-mix(in srgb,var(--warn) 28%,transparent);border-radius:7px;font-size:13px}
.doc table.mdtable{width:100%;border-collapse:collapse;margin:14px 0;font-size:12.8px;display:block;
  overflow-x:auto}
.doc table.mdtable th,.doc table.mdtable td{border:1px solid var(--line);padding:6px 9px;text-align:left}
.doc table.mdtable th{background:var(--panel-2);font-weight:600}
.doc a{color:var(--accent)}

/* ---------- browser-mode boot splash ---------- */
#boot{position:fixed;inset:0;z-index:200;display:grid;place-items:center;
  background:var(--bg);transition:opacity .35s ease}
.bootbox{text-align:center;max-width:440px;padding:26px}
.bootlogo{font-size:46px;color:var(--accent);line-height:1}
.bootbox h2{font-size:22px;margin:10px 0 14px;letter-spacing:-.3px}
.bootbox p{margin:0 0 14px;color:var(--ink-2);font-size:13.5px;min-height:20px}
.bootbox .bootsub{font-size:12px;color:var(--ink-3);margin:10px 0 0}
.bootbar{height:5px;background:var(--line);border-radius:3px;overflow:hidden}
.bootbar i{display:block;height:100%;width:0;background:var(--accent);
  border-radius:3px;transition:width .4s ease}
#boot.failed .bootbar i{background:var(--bad)}
#boot.failed .bootlogo{color:var(--bad)}

.doc figure{margin:18px 0 4px;text-align:center}
.doc figure img{max-width:100%;border:1px solid var(--line);border-radius:7px;background:#fff}
.doc p.figcap{margin:6px 0 20px;text-align:center;font-size:12.5px;color:var(--ink-3);
  font-style:italic;line-height:1.55}

/* ---------- scale drawings (web/draw.js) ---------- */
.drawing{width:100%;border-radius:7px;background:var(--panel-2);
  border:1px solid var(--line);overflow:hidden}
.drawing:empty{min-height:230px}
.drawing.tall:empty{min-height:330px}
.drawing svg{display:block;width:100%;height:auto}
.drawing text{user-select:none}
select.inline{font:inherit;font-size:12px;padding:2px 5px;border:1px solid var(--line);
  border-radius:5px;background:var(--panel);color:var(--ink)}

/* ---------- the soil survey table ---------- */
table.data th.rn,table.data td.rn{width:26px;text-align:right;color:var(--ink-3);
  font-size:12px;padding-inline-end:2px}
table.data th.derived,table.data td.derived{text-align:right;color:var(--ink-3);
  font-family:var(--mono);font-size:12px;white-space:nowrap}
table.data th[data-help]{cursor:help}
.drawing.sm{margin:2px 0 10px}

/* 1.8.0: multi-line inputs (touch zones, injection points, readings, route) */
.field.full textarea{width:100%;box-sizing:border-box;resize:vertical;
  font-family:ui-monospace,SFMono-Regular,Consolas,monospace;font-size:12px}

/* 1.8.4: DXF import panel and fence outlines in the electrode table */
.dxfbox { margin: 10px 0; border: 1px solid var(--line); border-radius: 8px; padding: 8px 12px; }
.dxfbox summary { cursor: pointer; font-weight: 600; }
.pfield input.wide { min-width: 260px; width: 100%; }
.pfield:has(input.wide) { grid-column: 1 / -1; }

table.data b.ok{color:var(--ok)} table.data .bad{color:var(--bad)}
#rkZones select{font-size:12px;padding:2px 4px;max-width:150px}

/* =====================================================================
   1.10.0 accessibility and responsive pass (WCAG 2.2 AA)
   ===================================================================== */
.sr-only{position:absolute!important;width:1px;height:1px;padding:0;margin:-1px;
  overflow:hidden;clip:rect(0 0 0 0);white-space:nowrap;border:0}
.skip-link{position:fixed;left:12px;top:-60px;z-index:300;background:var(--panel);color:var(--accent);
  padding:10px 16px;border-radius:8px;border:2px solid var(--focus);font-weight:600;text-decoration:none;
  box-shadow:var(--shadow)}
.skip-link:focus{top:10px}

/* one visible focus ring for every control reached by keyboard */
:focus-visible{outline:2px solid var(--focus);outline-offset:2px}
button:focus-visible,.btn:focus-within:has(input:focus-visible),.tab:focus-visible,.chip:focus-visible,
summary:focus-visible{outline:2px solid var(--focus);outline-offset:2px}
#main:focus,.pagehead h2:focus{outline:none}
#brand :focus-visible{outline-color:var(--on-accent)}

/* icons */
.ico{width:16px;height:16px;flex:0 0 16px}
.iconbtn{padding:6px 8px}
#btnTheme{padding:7px 9px}
button:hover .ico{color:inherit}

/* the file input fills its label so the whole button opens the picker */
.filebtn{position:relative;overflow:hidden}
.filebtn input[type=file]{position:absolute;inset:0;opacity:0;cursor:pointer;width:100%}

/* nav items are buttons now: reset the browser button look */
button.navitem{width:100%;border:0;background:transparent;font:inherit;font-size:14px;text-align:start;
  color:var(--ink-2);min-height:36px}
button.navitem:hover{background:var(--panel-2);color:var(--ink);border:0}
button.navitem.active{background:var(--accent-soft);color:var(--accent)}
/* completion is not colour only: a tick or a cross shape on the dot */
.navitem.done .dot,.navitem.failed .dot{width:14px;height:14px;display:grid;place-items:center;
  font-size:11px;font-weight:800;color:var(--panel);line-height:1}
.navitem.done .dot::before{content:'✓'}
.navitem.failed .dot::before{content:'!'}

/* tabs, chips and the expandable verdict rows */
.tab{min-height:32px;display:inline-flex;align-items:center}
button.chip{font:inherit;font-size:12px;background:var(--panel);min-height:26px}
button.chip.on{background:var(--accent);color:var(--on-accent);border-color:var(--accent)}
button.twist{border:0;background:transparent;padding:0;width:24px;height:24px;min-height:24px;
  justify-content:center;color:var(--ink-2);font-size:12px;vertical-align:-6px;margin-inline-end:2px}
button.twist:hover{color:var(--accent);border:0}
input[type=checkbox],input[type=radio]{width:18px;height:18px;accent-color:var(--accent);vertical-align:-4px}

/* chart text alternatives */
details.plotdata{margin:4px 10px 8px;font-size:12.5px}
details.plotdata summary{cursor:pointer;color:var(--accent);padding:4px 0;min-height:24px;width:max-content}
.plotdata-body{max-height:320px;overflow:auto;display:grid;gap:10px;grid-template-columns:repeat(auto-fill,minmax(220px,1fr));margin-top:6px}
.plotdata-body caption{text-align:left;font-weight:600;padding:4px 0;color:var(--ink)}

/* the menu button only exists on narrow screens */
.navtoggle{display:none;margin-inline-start:6px;border-color:color-mix(in srgb,var(--on-accent) 50%,transparent);background:transparent;color:var(--on-accent);padding:6px 8px}
.navtoggle:hover{color:var(--on-accent);border-color:var(--on-accent);background:color-mix(in srgb,var(--on-accent) 12%,transparent)}
.scrim{position:fixed;inset:0;background:rgba(10,18,26,.45);z-index:40}

/* wide tables scroll inside their card instead of pushing the page sideways */
.card .body{overflow-x:auto}

@media (max-width: 820px){
  #app{grid-template-columns:1fr;grid-template-rows:auto auto 1fr;
    grid-template-areas:"brand" "top" "main";height:100dvh}
  #brand{height:52px}
  #brand span{margin-inline-start:auto}
  .navtoggle{display:inline-flex}
  #top{height:auto;flex-wrap:wrap;padding:8px 12px;gap:6px}
  #top #projName{max-width:none!important;flex:1 1 100%}
  #top .grow{display:none}
  #top button .bl,#top .btn .bl{font-size:13px}
  #nav{position:fixed;z-index:50;top:52px;bottom:0;left:0;width:min(300px,86vw);
    transform:translateX(-102%);transition:transform .2s ease;box-shadow:0 10px 40px rgba(0,0,0,.25)}
  body.navopen #nav{transform:none}
  #main{padding:14px 12px 60px}
  .cols.c2{grid-template-columns:minmax(0,1fr)}
  .cols>*{min-width:0}
  .field{grid-template-columns:minmax(0,1fr) 104px 40px}
  .field.wide{grid-template-columns:minmax(0,1fr)}
  .theorywrap{grid-template-columns:minmax(0,1fr)}
  .doc{padding:16px 14px}
  .toc{position:static;max-height:260px}
  .plot{height:300px}.plot.tall{height:380px}
  .kpis{grid-template-columns:repeat(auto-fit,minmax(120px,1fr))}
  #toast{inset-inline:12px;bottom:12px}
  .toast{max-width:none}
  .tabs{flex-wrap:nowrap;overflow-x:auto;scrollbar-width:thin}
  .tab{white-space:nowrap}
  button,.btn{min-height:40px}
  button.twist{min-height:24px}
  #modal .box{width:calc(100vw - 16px);max-height:92dvh}
}

/* honour a reduced-motion setting (WCAG 2.3.3) */
@media (prefers-reduced-motion: reduce){
  *,*::before,*::after{animation-duration:.01ms!important;animation-iteration-count:1!important;
    transition-duration:.01ms!important;scroll-behavior:auto!important}
  .spinner{animation:none;border-top-color:var(--accent);border-right-color:var(--accent)}
}

/* forced-colours (Windows high contrast): keep the state cues */
@media (forced-colors: active){
  .navitem.active,.tab.active,.chip.on{outline:2px solid CanvasText}
  .badge{border:1px solid CanvasText}
}

/* ---------- 3-D electrode view (web/grid3d.js) ---------- */
.g3d{position:relative;width:100%;height:100%;min-height:380px;border-radius:7px;overflow:hidden;
  background:linear-gradient(var(--panel-2),var(--panel))}
.g3d canvas{display:block;width:100%;height:100%;outline:none}
.g3d canvas:focus-visible{outline:2px solid var(--focus);outline-offset:-2px}
.g3d-bar{position:absolute;left:8px;top:8px;right:8px;display:flex;gap:6px;flex-wrap:wrap;align-items:center;pointer-events:none}
.g3d-bar>*{pointer-events:auto}
.g3d-bar button{padding:4px 9px;font-size:12px;min-height:28px;background:color-mix(in srgb,var(--panel) 88%,transparent)}
.g3d-bar button[aria-pressed=true]{background:var(--accent-soft);color:var(--accent);border-color:var(--accent)}
.g3d-bar label{display:inline-flex;align-items:center;gap:6px;font-size:12px;color:var(--ink-2);
  background:color-mix(in srgb,var(--panel) 88%,transparent);border:1px solid var(--line);border-radius:7px;padding:3px 8px}
.g3d-bar input[type=range]{width:90px;padding:0;border:0;background:transparent}
.g3d-legend{position:absolute;right:10px;bottom:10px;display:grid;gap:8px;pointer-events:none}
.g3d-key{background:color-mix(in srgb,var(--panel) 90%,transparent);border:1px solid var(--line);border-radius:7px;
  padding:6px 9px;font-size:12px;color:var(--ink-2);min-width:170px}
.g3d-key b{color:var(--ink);font-weight:600;display:block;margin-bottom:3px}
.g3d-key i{display:block;height:9px;border-radius:3px;margin:3px 0}
.g3d-key span{display:flex;justify-content:space-between;font-variant-numeric:tabular-nums}
.g3d-tip{position:absolute;pointer-events:none;background:var(--panel);color:var(--ink);border:1px solid var(--line);
  border-radius:7px;padding:6px 9px;font-size:12px;box-shadow:var(--shadow);white-space:nowrap;transform:translate(12px,12px)}
.g3d-help{position:absolute;left:10px;bottom:10px;font-size:12px;color:var(--ink-2);max-width:52%;
  background:color-mix(in srgb,var(--panel) 85%,transparent);border-radius:6px;padding:4px 8px}
@media (max-width:820px){.g3d-help{display:none}.g3d-key{min-width:140px}}
/* the drawing viewer is white paper in both themes, so its placeholder keeps dark ink */
#dView .empty{color:#5f6c78;border-color:#c9d2da}