:root{
    --accent:#c89b3c;
    --good:#4e9b74;
    --blue:#4f7cac;
    --purple:#665d8a;
    --gold:#c89b3c;
    --red:#b86a6a;
  }
  header{margin-bottom:38px;}
  .eyebrow{font-family:'Space Mono',monospace;font-size:12px;letter-spacing:0.32em;text-transform:uppercase;color:var(--accent);margin-bottom:14px;}
  h1{font-family:'Merriweather',serif;font-weight:500;font-size:clamp(32px,5vw,52px);line-height:1.04;letter-spacing:-0.02em;max-width:23ch;}
  h1 em{font-style:italic;color:var(--red);}
  .sub{color:var(--muted);font-size:18px;line-height:1.6;max-width:74ch;margin-top:18px;}

  .layout{display:grid;grid-template-columns:1.38fr 1fr;gap:28px;margin-top:42px;align-items:start;}
  @media(max-width:900px){.layout{grid-template-columns:1fr;}}
  .stage{background:var(--panel);border:1px solid var(--line);border-radius:20px;padding:14px;position:relative;overflow:hidden;}
  canvas{width:100%;height:540px;display:block;border-radius:12px;}
  .stage-tag{position:absolute;top:25px;left:26px;font-family:'Space Mono',monospace;font-size:12px;letter-spacing:.14em;color:var(--accent);text-transform:uppercase;pointer-events:none;}
  .hint{position:absolute;bottom:20px;left:0;right:0;text-align:center;font-family:'Space Mono',monospace;font-size:10px;letter-spacing:.1em;color:var(--faint);text-transform:uppercase;pointer-events:none;}
  .side{display:flex;flex-direction:column;gap:18px;}
  .controls,.factcard,.legend{background:var(--panel);border:1px solid var(--line);border-radius:18px;padding:22px 24px;}
  .ctrl-label{font-family:'Space Mono',monospace;font-size:12px;letter-spacing:.1em;color:var(--muted);text-transform:uppercase;}
  .pick{display:grid;grid-template-columns:repeat(4,1fr);gap:8px;margin:14px 0 20px;}
  button{font-family:'DM Sans',sans-serif;font-weight:700;color:var(--ink);background:transparent;border:1px solid var(--line);border-radius:8px;padding:11px 8px;cursor:pointer;transition:.18s;}
  button:hover{border-color:var(--blue);background:rgba(79,124,172,.1);}
  button.active{border-color:var(--good);color:var(--good);background:rgba(78,155,116,.08);}
  .pick button{font-family:'Merriweather',serif;font-size:15px;}
  .ctrl-row{display:flex;align-items:center;justify-content:space-between;}
  .ctrl-val{font-family:'Space Mono',monospace;font-size:14px;color:var(--blue);}
  input[type=range]{-webkit-appearance:none;appearance:none;width:100%;height:4px;border-radius:4px;background:var(--panel-raised);outline:none;margin:13px 0 18px;}
  input[type=range]::-webkit-slider-thumb{-webkit-appearance:none;width:18px;height:18px;border-radius:50%;background:#fff;border:3px solid var(--blue);cursor:pointer;}
  .btns{display:flex;gap:10px}.btns button{flex:1;font-size:12px;letter-spacing:.08em;text-transform:uppercase;}
  .factcard .fc-title{font-family:'Merriweather',serif;font-size:20px;color:var(--blue);margin-bottom:8px;}
  .fc-desc{color:var(--muted);font-size:14px;line-height:1.55;margin-bottom:15px;}
  .fc-row{display:flex;justify-content:space-between;gap:12px;align-items:baseline;padding:8px 0;border-top:1px solid var(--line);}
  .fc-row .k{font-family:'Space Mono',monospace;font-size:11px;letter-spacing:.05em;color:var(--muted);text-transform:uppercase;}
  .fc-row .v{font-family:'Space Mono',monospace;font-size:13px;color:var(--good);text-align:right;}
  .legend{display:flex;flex-direction:column;gap:12px}.leg-item{display:flex;align-items:center;gap:12px}.dot{width:13px;height:13px;border-radius:50%;flex-shrink:0}.dot.blue{background:var(--blue)}.dot.gold{background:var(--gold)}.dot.red{background:var(--red)}
  .leg-text{font-size:15px}.leg-text span{display:block;color:var(--muted);font-size:13px;margin-top:1px;}
  .concept{margin-top:48px}.concept h2{font-family:'Merriweather',serif;font-weight:500;font-size:26px;margin-bottom:24px}.steps{display:grid;grid-template-columns:repeat(3,1fr);gap:20px}@media(max-width:780px){.steps{grid-template-columns:1fr}}
  .step{background:var(--panel);border:1px solid var(--line);border-radius:16px;padding:26px}.step-num{font-family:'Space Mono',monospace;font-size:13px;color:var(--accent);letter-spacing:.1em;margin-bottom:14px}.step h3{font-family:'Merriweather',serif;font-weight:500;font-size:19px;margin-bottom:10px;color:var(--blue)}.step p{color:var(--muted);font-size:15px;line-height:1.62}.eq{font-family:'Space Mono',monospace;font-size:14px;color:var(--ink);background:rgba(255,255,255,.04);border:1px solid var(--line);border-radius:8px;padding:10px 12px;margin-top:14px}
  .result{margin-top:42px;background:var(--panel);border:1px solid var(--line);border-radius:18px;padding:32px}.result .label{font-family:'Space Mono',monospace;font-size:12px;letter-spacing:.18em;text-transform:uppercase;color:var(--blue);margin-bottom:18px}.electronics-eq{font-family:'Space Mono',monospace;color:var(--muted);font-size:18px;line-height:1.7;border-bottom:1px solid var(--line);padding-bottom:16px}.answer{color:var(--muted);font-size:18px;line-height:1.6;margin-top:18px}.answer b{color:var(--good)}