/* =============================================================================
   TradeSchool V15 — design layer
   -----------------------------------------------------------------------------
   Loaded after main.css and overrides it. Kept separate so the V7-V14 CSS stays
   readable as history rather than being rewritten in place.

   THE CONCEPT: the equipment data plate.

   Every trade in this curriculum has the same ritual at the start of a job. You
   find the plate, the tag, the marker or the stamp, and you read it before you
   touch anything. A motor nameplate, a valve tag, an ASME A13.1 pipe marker, an
   arc-flash label, a WPS number on a weldment, a header stamp on lumber. The
   plate is the trades' native interface, so it is this site's interface too.

   PALETTE: pulled from real field colour coding, not from a trend.
     - ground is warm graphite, the colour of unpainted tool steel and enclosure
       powder coat, not the near-black that every dark UI defaults to
     - each trade's signal colour is the colour that trade actually uses:
         electrical    arc-flash / hazard label yellow
         hvac          refrigerant cylinder rose (the R-410A cylinder colour)
         plumbing      ASME A13.1 potable water green
         industrial    machine-guard safety orange
         welding       oxide red, the colour of hot then quenched steel
         construction  chalk-line and blueprint blue
     - danger / warning / notice follow ANSI Z535.1

   TYPE:
     - Saira Condensed for display. Condensed gothic is the class of face that
       is actually silkscreened onto equipment and stencilled onto signage.
     - Saira for body, so headings and text share a skeleton.
     - IBM Plex Mono for data, labels and every value the labs compute. It was
       drawn for engineering documentation, which is what these readouts are.

   SIGNATURE: .nameplate. Engraved rows on a brushed plate with corner fasteners,
   used as the concept header. It carries the trade, the unit, the one-line
   definition and the field-verification cue in the same reading order as a real
   data plate.
   ========================================================================== */

:root{
  /* --- ground ------------------------------------------------------------ */
  --bg:#101317;
  --bg2:#141820;
  --panel:#171B21;
  --panel2:#1E232B;
  --line:rgba(233,229,220,.10);
  --line2:rgba(233,229,220,.19);
  --text:#E9E5DC;
  --muted:#97A1AD;
  --shadow:0 24px 64px rgba(0,0,0,.42);
  --radius:14px;

  /* --- trade signal colours ---------------------------------------------- */
  --sig-electrical:#F0B429;
  --sig-hvac:#E0607E;
  --sig-plumbing:#2FA36B;
  --sig-industrial:#E4712F;
  --sig-welding:#C4472F;
  --sig-construction:#4A87C7;

  /* --- ANSI Z535 status -------------------------------------------------- */
  --sig-danger:#D93B2B;
  --sig-warn:#F0B429;
  --sig-notice:#4A87C7;
  --sig-safe:#2FA36B;

  /* Default accent. Every legacy rule that referenced --lime now resolves to
     the active trade's signal colour, so the whole app re-themes per world. */
  --accent:#C9CDD4;
  --lime:var(--accent);
  --lime2:var(--accent);
  --cyan:var(--sig-construction);
  --orange:var(--sig-industrial);
  --red:var(--sig-danger);

  --mono:"IBM Plex Mono",ui-monospace,SFMono-Regular,Menlo,monospace;
  --sans:"Saira","Saira Condensed",system-ui,-apple-system,sans-serif;
  --display:"Saira Condensed","Saira",system-ui,sans-serif;
}

/* Per-world accent. app.js already puts .theme-<world> on the shell. */
/* main.css scopes these as `.shell.theme-*`, so match that specificity. */
.shell.theme-electrical{--accent:var(--sig-electrical);--lime:var(--sig-electrical);--accent-soft:rgba(240,180,41,.09);--trade-line:rgba(240,180,41,.3)}
.shell.theme-hvac{--accent:var(--sig-hvac);--lime:var(--sig-hvac);--accent-soft:rgba(224,96,126,.09);--trade-line:rgba(224,96,126,.3)}
.shell.theme-plumbing{--accent:var(--sig-plumbing);--lime:var(--sig-plumbing);--accent-soft:rgba(47,163,107,.09);--trade-line:rgba(47,163,107,.3)}
.shell.theme-industrial{--accent:var(--sig-industrial);--lime:var(--sig-industrial);--accent-soft:rgba(228,113,47,.09);--trade-line:rgba(228,113,47,.3)}
.shell.theme-welding{--accent:var(--sig-welding);--lime:var(--sig-welding);--accent-soft:rgba(196,71,47,.1);--trade-line:rgba(196,71,47,.32)}
.shell.theme-construction{--accent:var(--sig-construction);--lime:var(--sig-construction);--accent-soft:rgba(74,135,199,.09);--trade-line:rgba(74,135,199,.3)}
.shell.theme-home{--accent:#C9CDD4;--lime:#C9CDD4;--accent-soft:rgba(201,205,212,.07);--trade-line:rgba(201,205,212,.22)}

/* --------------------------------------------------------------------------
   Ground. The old radial washes read as generic dark-UI atmosphere; replaced
   with a faint machined grid, which is what a shop drawing sits on.
   ------------------------------------------------------------------------ */
body{
  background:
    linear-gradient(rgba(233,229,220,.016) 1px,transparent 1px) 0 0/72px 72px,
    linear-gradient(90deg,rgba(233,229,220,.016) 1px,transparent 1px) 0 0/72px 72px,
    var(--bg);
  font-family:var(--sans);
  font-weight:400;
  -webkit-font-smoothing:antialiased;
}
::selection{background:var(--accent);color:#101317}

/* Chanel's rule: one accessory off. The ambient particle canvas was atmosphere
   that said nothing about trades. */
.particle-canvas{display:none!important}

h1,h2,h3,.brand{font-family:var(--display);letter-spacing:-.005em;font-weight:700}
h1{letter-spacing:-.01em}
.hero h1,.home-intro h1{
  font-family:var(--display);
  font-weight:700;
  letter-spacing:-.012em;
  line-height:.92;
  text-transform:none;
}
.hero h1 span,.home-intro h1 span{color:var(--accent)}
.eyebrow{
  font-family:var(--mono);font-size:10px;font-weight:500;
  letter-spacing:.16em;text-transform:uppercase;color:var(--accent);
}

/* --------------------------------------------------------------------------
   Chrome
   ------------------------------------------------------------------------ */
.topbar{background:rgba(16,19,23,.86);border-bottom:1px solid var(--line);backdrop-filter:blur(14px)}
.brand-mark{
  border-radius:3px;border:1px solid var(--line2);color:var(--accent);
  background:linear-gradient(160deg,#232830,#171B21);box-shadow:none;
}
.icon-btn,.ghost-btn,.solid-btn{border-radius:4px;font-family:var(--sans);font-weight:600}
.solid-btn{background:var(--accent);color:#101317;border-color:var(--accent)}
.solid-btn:hover{transform:none;filter:brightness(1.08);box-shadow:none}
.kbd{border-radius:3px;font-family:var(--mono)}

.footer{
  display:flex;flex-wrap:wrap;gap:12px 28px;align-items:center;
  border-top:1px solid var(--line);padding-top:20px;
  font-family:var(--mono);font-size:11px;color:var(--muted);
}
.footer-link{
  background:none;border:0;padding:0;cursor:pointer;
  font:inherit;color:var(--accent);text-decoration:underline;
  text-underline-offset:3px;text-decoration-thickness:1px;
}
.footer-link:hover{color:var(--text)}

/* Panels: square off the oversized pill radius. Trade equipment has corners. */
.world-card,.path-card,.concept-card,.practice-card,.stat-card,
.tool-card,.workspace,.big-sim-stage,.circuit-controls,.topic-context-card,
.search-box,.metric,.instruction,.lab-live-explain,.reference-lead,
.field-evidence,.behavior-flow,.field-story,.safety-note-v7,.course-hero{
  border-radius:6px;
}
.world-machine{border-radius:8px}

/* --------------------------------------------------------------------------
   SIGNATURE — the equipment data plate
   ------------------------------------------------------------------------ */
.nameplate{
  position:relative;
  margin:0 0 28px;
  padding:22px 26px 20px;
  border:1px solid var(--line2);
  border-radius:4px;
  background:
    repeating-linear-gradient(90deg,rgba(233,229,220,.014) 0 2px,transparent 2px 5px),
    linear-gradient(158deg,#252A32 0%,#1B1F26 46%,#20252D 100%);
  box-shadow:inset 0 1px 0 rgba(233,229,220,.07), 0 12px 32px rgba(0,0,0,.34);
}
/* four corner fasteners */
.nameplate:before,.nameplate:after,
.nameplate .plate-rows:before,.nameplate .plate-rows:after{
  content:"";position:absolute;width:7px;height:7px;border-radius:50%;
  background:radial-gradient(circle at 34% 30%,#5c6470,#2b3038 68%);
  box-shadow:inset 0 0 0 1px rgba(0,0,0,.5);
}
.nameplate:before{left:9px;top:9px}
.nameplate:after{right:9px;top:9px}
.nameplate .plate-rows:before{left:9px;bottom:9px}
.nameplate .plate-rows:after{right:9px;bottom:9px}

.nameplate .plate-head{
  display:flex;flex-wrap:wrap;gap:10px 16px;align-items:baseline;
  padding-bottom:14px;margin-bottom:14px;
  border-bottom:1px solid rgba(233,229,220,.13);
}
.nameplate .plate-mark{
  font-family:var(--mono);font-size:10px;letter-spacing:.18em;
  text-transform:uppercase;color:var(--accent);
}
.nameplate .plate-title{
  font-family:var(--display);font-size:clamp(30px,4vw,50px);
  font-weight:700;line-height:1;letter-spacing:-.01em;margin:0;flex:1 1 100%;
}
.nameplate .plate-rows{
  position:relative;
  display:grid;grid-template-columns:repeat(auto-fit,minmax(190px,1fr));
  gap:2px;
}
.nameplate .plate-row{
  padding:9px 12px;background:rgba(16,19,23,.34);
  border:1px solid rgba(233,229,220,.06);
}
.nameplate .plate-row small{
  display:block;font-family:var(--mono);font-size:9px;letter-spacing:.14em;
  text-transform:uppercase;color:var(--muted);margin-bottom:5px;
}
.nameplate .plate-row b{
  display:block;font-family:var(--sans);font-weight:600;font-size:14px;
  line-height:1.35;color:var(--text);
}
.nameplate .plate-row.wide{grid-column:1/-1}
.nameplate .plate-row.wide b{font-weight:500;font-size:15px}

/* --------------------------------------------------------------------------
   Fixes for defects found in the V15 audit
   ------------------------------------------------------------------------ */

/* 1. The concept "Visual reference" panel rendered as a large white box on a
      dark page, because the figure had no background of its own. */
.visual-learning figure,.concept-visual,.topic-photo,.visual-frame{
  background:var(--panel)!important;
  border:1px solid var(--line);
  border-radius:6px;
  overflow:hidden;
}
.visual-learning img,.concept-visual img,.topic-photo img,.visual-frame img{
  display:block;width:100%;height:auto;background:var(--panel2);
}
.visual-learning figcaption,.topic-photo figcaption{
  padding:14px 16px;background:var(--panel2);border-top:1px solid var(--line);
}
.topic-photo figcaption b{font-family:var(--display);font-weight:600;font-size:15px}
.topic-photo figcaption em,.visual-learning figcaption em{
  display:block;margin-top:6px;font-family:var(--mono);font-size:10px;
  font-style:normal;color:var(--muted);
}
/* SVG diagrams are drawn on their own ground and must not be letterboxed. */
.visual-learning img[src$=".svg"],.topic-photo img[src$=".svg"]{background:transparent}

/* 2. Portrait hero photos were blowing the world hero to ~800px tall. */
.course-hero{display:grid;grid-template-columns:minmax(0,420px) 1fr;align-items:stretch}
.course-hero-media{position:relative;overflow:hidden;min-height:260px;max-height:420px}
.course-hero-media img{width:100%;height:100%;object-fit:cover;object-position:center}
.course-hero-copy{padding:34px 38px;display:flex;flex-direction:column;justify-content:center}
.field-caption{
  font-family:var(--mono);font-size:9px;letter-spacing:.14em;
  background:rgba(16,19,23,.9);border:1px solid var(--line);border-radius:3px;
}
@media(max-width:860px){
  .course-hero{grid-template-columns:1fr}
  .course-hero-media{max-height:220px}
  .course-hero-copy{padding:24px 20px}
}

/* 3. The home hero collage overlapped its own captions. Replaced with a
      three-up strip that shows all three photos in full. */
.home-hero-strip{
  display:grid;grid-template-columns:repeat(3,1fr);gap:8px;align-content:start;
}
.home-hero-strip figure{
  margin:0;position:relative;border:1px solid var(--line);border-radius:5px;
  overflow:hidden;aspect-ratio:3/4;background:var(--panel2);
}
.home-hero-strip img{width:100%;height:100%;object-fit:cover;display:block}
.home-hero-strip figcaption{
  position:absolute;left:0;right:0;bottom:0;padding:9px 10px;
  background:linear-gradient(transparent,rgba(16,19,23,.93));
  font-family:var(--mono);font-size:9px;letter-spacing:.1em;
  text-transform:uppercase;color:var(--text);
}
@media(max-width:720px){.home-hero-strip{grid-template-columns:1fr 1fr}
  .home-hero-strip figure:last-child{display:none}}

/* 4. Tabs read as generic pills. Now they read as a machine selector. */
.course-tabs{gap:0;border:1px solid var(--line);border-radius:5px;overflow:hidden;width:max-content}
.course-tabs button{
  border:0;border-right:1px solid var(--line);border-radius:0;
  font-family:var(--mono);font-size:11px;letter-spacing:.09em;text-transform:uppercase;
  padding:11px 18px;background:transparent;color:var(--muted);
}
.course-tabs button:last-child{border-right:0}
.course-tabs button.active{background:var(--accent);color:#101317;font-weight:600}

/* --------------------------------------------------------------------------
   Standards and currency page
   ------------------------------------------------------------------------ */
.standards-head{max-width:760px}
.standards-list{display:grid;gap:34px;padding:12px 0 40px}
.standards-group h2{
  font-family:var(--display);font-size:15px;font-weight:600;
  letter-spacing:.13em;text-transform:uppercase;color:var(--accent);
  padding-bottom:9px;margin:0 0 14px;border-bottom:1px solid var(--line);
}
.standards-group.theme-electrical{--accent:var(--sig-electrical)}
.standards-group.theme-hvac{--accent:var(--sig-hvac)}
.standards-group.theme-plumbing{--accent:var(--sig-plumbing)}
.standards-group.theme-industrial{--accent:var(--sig-industrial)}
.standards-group.theme-welding{--accent:var(--sig-welding)}
.standards-group.theme-construction{--accent:var(--sig-construction)}

.standard-card{
  display:grid;grid-template-columns:minmax(0,290px) 1fr;gap:0;
  border:1px solid var(--line);border-radius:5px;overflow:hidden;margin-bottom:10px;
  background:var(--panel);
}
.standard-plate{
  padding:18px 20px;background:linear-gradient(158deg,#252A32,#1B1F26);
  border-right:1px solid var(--line);
}
.standard-plate span{
  display:block;font-family:var(--mono);font-size:9px;letter-spacing:.14em;
  text-transform:uppercase;color:var(--muted);margin-bottom:5px;
}
.standard-plate b{
  display:block;font-family:var(--sans);font-weight:600;font-size:15px;
  line-height:1.35;color:var(--text);margin-bottom:14px;
}
.standard-plate b:last-child{margin-bottom:0}
.standard-plate .standard-current{color:var(--accent);font-family:var(--mono);font-size:13px}
.standard-body{padding:18px 22px}
.standard-body p{margin:0 0 14px;line-height:1.6;color:#C4CBD4;font-size:14px}
.standard-sowhat{
  margin:0!important;padding-top:14px;border-top:1px solid var(--line);color:var(--text)!important;
}
.standard-sowhat small{
  display:block;font-family:var(--mono);font-size:9px;letter-spacing:.14em;
  text-transform:uppercase;color:var(--muted);margin-bottom:6px;
}
.standards-foot{
  border-top:1px solid var(--line);padding:22px 0 60px;max-width:820px;
  color:var(--muted);font-size:13px;line-height:1.65;
}
@media(max-width:760px){.standard-card{grid-template-columns:1fr}
  .standard-plate{border-right:0;border-bottom:1px solid var(--line)}}

/* --------------------------------------------------------------------------
   V15 labs
   ------------------------------------------------------------------------ */
.lab15-stage{display:grid;place-items:center;padding:18px;min-height:520px}
.lab15-svg{width:100%;height:auto;max-height:560px}
.lab15-svg text{font-family:var(--mono)}

.lab15-inputs{display:grid;gap:8px}
.lab15-io{display:flex;align-items:center;justify-content:space-between;gap:10px}
.lab15-io span{font-family:var(--mono);font-size:11px;letter-spacing:.08em;color:var(--muted)}
.lab15-dirs{display:grid;grid-template-columns:1fr auto 1fr;gap:6px;margin:10px 0}

.push{
  border:1px solid var(--line2);background:rgba(233,229,220,.03);color:var(--text);
  border-radius:4px;padding:10px 12px;cursor:pointer;
  font-family:var(--mono);font-size:11px;letter-spacing:.07em;transition:.12s ease;
}
.push:hover{border-color:var(--accent)}
.push.on{background:var(--accent);color:#101317;border-color:var(--accent);font-weight:600}

.lab15-toggle{
  display:flex;align-items:center;gap:10px;padding:9px 2px;cursor:pointer;
  font-size:13px;color:#C4CBD4;
}
.lab15-toggle input{accent-color:var(--accent);width:16px;height:16px;cursor:pointer}

.metric-row{display:grid;grid-template-columns:repeat(3,1fr);gap:6px;margin:12px 0}
.metric{padding:11px 12px;border:1px solid var(--line);background:var(--panel2)}
.metric b{font-family:var(--mono);font-size:15px;color:var(--text);display:block}
.metric small{
  display:block;margin-top:4px;font-family:var(--mono);font-size:9px;
  letter-spacing:.09em;text-transform:uppercase;color:var(--muted);
}
.lab-live-explain{
  padding:14px 15px;border:1px solid var(--line);border-left:2px solid var(--accent);
  background:var(--panel2);
}
.lab-live-explain b{display:block;font-family:var(--display);font-weight:600;font-size:15px;margin-bottom:6px}
.lab-live-explain span{display:block;font-size:13px;line-height:1.6;color:#B3BBC5}
.sim-note{font-size:11px!important;line-height:1.6;color:var(--muted);margin-top:14px}
.workspace-bar{font-family:var(--mono);font-size:10px;letter-spacing:.11em;text-transform:uppercase}

.range-row{margin-bottom:14px}
.range-head{display:flex;justify-content:space-between;align-items:baseline;margin-bottom:7px}
.range-head span{font-size:13px;color:#C4CBD4}
.range-head b{font-family:var(--mono);font-size:12px;color:var(--accent)}
input[type=range]{width:100%;accent-color:var(--accent)}

@keyframes dvRise{from{opacity:0;transform:translateY(14px)}50%{opacity:1}to{opacity:0;transform:translateY(-26px)}}
.dv-air{animation:dvRise 1.6s linear infinite}
.dv-air:nth-child(2){animation-delay:.5s}
.dv-air:nth-child(3){animation-delay:1s}

/* --------------------------------------------------------------------------
   Quality floor
   ------------------------------------------------------------------------ */
:focus-visible{outline:2px solid var(--accent);outline-offset:2px;border-radius:2px}
@media(prefers-reduced-motion:reduce){
  *,*:before,*:after{animation-duration:.001ms!important;animation-iteration-count:1!important;transition-duration:.001ms!important}
  html{scroll-behavior:auto}
}

/* Home "how this is built": the section previously had a heading and no body. */
.research-note{border-top:1px solid var(--line);padding:40px 0 20px;display:grid;gap:22px}
.research-note h2{font-family:var(--display);font-size:clamp(24px,3vw,34px);font-weight:700;margin:6px 0 0}
.research-note small{font-family:var(--mono);font-size:10px;letter-spacing:.16em;text-transform:uppercase;color:var(--accent)}
.research-note>p{max-width:640px;color:#B3BBC5;line-height:1.65;margin:0}
.method-rows{display:grid;grid-template-columns:repeat(auto-fit,minmax(250px,1fr));gap:8px}
.method-row{padding:18px 18px 20px;border:1px solid var(--line);background:var(--panel);border-top:2px solid var(--accent)}
.method-row b{display:block;font-family:var(--display);font-size:38px;font-weight:700;line-height:1;color:var(--text);margin-bottom:10px}
.method-row span{display:block;font-size:13px;line-height:1.6;color:var(--muted)}
.home-proof{display:flex;flex-wrap:wrap;gap:8px;margin-top:26px}
.home-proof span{font-family:var(--mono);font-size:11px;color:var(--muted);border:1px solid var(--line);border-radius:3px;padding:7px 11px}
.home-proof b{color:var(--text)}

/* main.css gives .research-note a two-column grid; the method rows are a full
   width band under both columns. */
.method-rows{grid-column:1/-1}

/* --------------------------------------------------------------------------
   Audit fix: the "Visual reference" panel rendered as a large white slab.
   main.css set `.reference-photo img{background:#e8ebe9}` behind an
   object-fit:contain image, so any photo that was not exactly 16:9 showed
   near-white letterbox bars on a dark page. Portrait photos showed more bar
   than photo.
   ------------------------------------------------------------------------ */
.reference-photo{border-radius:6px;background:var(--panel)}
.reference-photo img,
.v7-photo img{
  background:var(--panel2)!important;
  height:auto!important;
  max-height:460px;
  object-fit:contain;
  padding:14px;
}
/* Diagrams are drawn edge to edge on their own ground: no padding, no fill. */
.reference-photo img[src$=".svg"],
.v7-photo img[src$=".svg"]{background:transparent!important;padding:0;max-height:none}
.reference-photo figcaption,.v7-photo figcaption{
  display:grid;gap:6px;padding:14px 16px;
  background:var(--panel2);border-top:1px solid var(--line);
  font-size:12px;line-height:1.55;color:var(--muted);
}
.reference-photo figcaption b{
  font-family:var(--display);font-weight:600;font-size:15px;color:var(--text);max-width:none;
}

/* Audit fix: the concept hero clipped the nameplate, because the hero row had
   a fixed height inherited from the old image-led header. */
.reference-hero{align-items:start;min-height:0;height:auto}
.reference-hero>div{min-height:0;height:auto}
.reference-hero>img{
  max-height:300px;object-fit:cover;border-radius:6px;
  align-self:start;background:var(--panel2);
}
.reference-hero>img[src$=".svg"]{object-fit:contain;background:transparent;max-height:240px}
.reference-actions{margin-top:20px;display:flex;gap:8px;flex-wrap:wrap}

/* The lesson nav "next" chip inherited the old lime. Tie it to the trade. */
.lesson-nav .next,.lesson-nav b,.lesson-next{color:inherit}