:root{
  --yellow:#d6b000;
  --yellow-soft:#fff7cf;
  --ink:#242824;
  --muted:#687168;
  --line:#dedfd9;
  --card:#fff;
  --bg:#f6f4ef;
  --green:#355e3b;
  font-family:system-ui,-apple-system,BlinkMacSystemFont,"Segoe UI",sans-serif;
  color:var(--ink);
  background:transparent;
}
*{box-sizing:border-box}
html,body{margin:0;padding:0;background:transparent;color:var(--ink)}
button,input,select{font:inherit}
button{cursor:pointer}
.electricity-app{width:100%;max-width:1120px;margin:0 auto;padding:0 0 28px}
.hero{display:grid;grid-template-columns:minmax(0,1fr) 280px;gap:26px;padding:34px;border:2px solid var(--yellow);border-top-width:6px;border-radius:24px;background:#fff;box-shadow:0 10px 30px rgba(30,35,31,.06)}
.eyebrow{margin:0 0 8px;color:#735e00;font-size:.78rem;font-weight:850;letter-spacing:.1em;text-transform:uppercase}
h1,h2,h3{font-family:Georgia,"Times New Roman",serif;color:#1f2520}
h1{margin:0;font-size:clamp(2.15rem,5vw,3.7rem);line-height:1.02}
.lead{max-width:760px;margin:16px 0 0;color:var(--muted);font-size:1.06rem;line-height:1.65}
.progress-card{align-self:start;padding:18px;border:1px solid var(--line);border-radius:16px;background:var(--bg)}
.progress-card strong{display:block;margin-bottom:10px}
.progress-track{height:10px;overflow:hidden;border-radius:999px;background:#e5e4de}.progress-track span{display:block;width:0;height:100%;background:var(--green);transition:width .2s ease}
.text-button{margin-top:10px;padding:0;border:0;background:transparent;color:#6c5b00;font-size:.86rem;text-decoration:underline}
.safety{margin:18px 0;padding:18px 20px;border-left:5px solid var(--yellow);border-radius:12px;background:var(--yellow-soft);line-height:1.55}.safety strong{display:block;margin-bottom:5px}.safety p{margin:0;color:#554c21}
.toolbar{display:grid;grid-template-columns:minmax(0,1fr) 230px;gap:14px;margin:20px 0}.toolbar label{display:flex;flex-direction:column;gap:6px;color:var(--muted);font-size:.8rem;font-weight:750;text-transform:uppercase;letter-spacing:.04em}.toolbar input,.toolbar select,.section-heading input{width:100%;min-height:46px;padding:10px 13px;border:1px solid var(--line);border-radius:12px;background:#fff;color:var(--ink);text-transform:none;letter-spacing:0;font-weight:500}
.module-grid{display:grid;grid-template-columns:repeat(3,minmax(0,1fr));gap:16px}
.module-card{position:relative;display:flex;flex-direction:column;min-height:245px;padding:22px;border:1px solid var(--line);border-top:5px solid var(--yellow);border-radius:18px;background:#fff;text-align:left;color:inherit;box-shadow:0 8px 22px rgba(30,35,31,.05);transition:transform .15s ease,box-shadow .15s ease}.module-card:hover{transform:translateY(-2px);box-shadow:0 14px 28px rgba(30,35,31,.09)}.module-card.done{border-top-color:var(--green)}
.module-number{display:inline-flex;align-items:center;justify-content:center;width:42px;height:42px;border-radius:12px;background:var(--yellow-soft);color:#705c00;font-weight:850}.module-card.done .module-number{background:#e4efe4;color:var(--green)}
.module-card h2{margin:18px 0 8px;font-size:1.35rem}.module-card p{margin:0;color:var(--muted);line-height:1.5}.module-meta{display:flex;justify-content:space-between;gap:10px;margin-top:auto;padding-top:20px;color:#777f78;font-size:.78rem}.done-badge{font-weight:800;color:var(--green)}
.lesson{margin-top:18px}.back-button{margin:0 0 14px;padding:10px 14px;border:1px solid var(--line);border-radius:999px;background:#fff;color:var(--ink);font-weight:750}.lesson article{padding:clamp(22px,4vw,40px);border:1px solid var(--line);border-radius:22px;background:#fff;box-shadow:0 10px 30px rgba(30,35,31,.05)}
.lesson h2{margin:0 0 8px;font-size:clamp(1.9rem,4vw,3rem)}.lesson-intro{margin:0 0 24px;color:var(--muted);font-size:1.05rem;line-height:1.65}.lesson h3{margin:28px 0 10px;font-size:1.35rem}.lesson p,.lesson li{line-height:1.68}.lesson ul,.lesson ol{padding-left:1.25rem}.formula{margin:16px 0;padding:16px 18px;border-radius:14px;background:#f3f4ef;font-family:ui-monospace,SFMono-Regular,Menlo,monospace;font-size:1.03rem;font-weight:700}.example{margin:18px 0;padding:18px;border:1px solid #dfe7df;border-radius:14px;background:#f8fbf8}.warning{margin:18px 0;padding:18px;border:1px solid #e8d880;border-radius:14px;background:#fff9dd}.tip{margin:18px 0;padding:18px;border-left:4px solid var(--green);border-radius:12px;background:#f0f6f1}.lesson table{width:100%;border-collapse:collapse;margin:18px 0;font-size:.95rem}.lesson th,.lesson td{padding:10px 12px;border-bottom:1px solid var(--line);text-align:left;vertical-align:top}.lesson th{background:#f4f3ef}
.quiz{margin-top:30px;padding:20px;border-radius:16px;background:#f7f6f1}.quiz h3{margin-top:0}.quiz-option{display:block;width:100%;margin:8px 0;padding:12px 14px;border:1px solid var(--line);border-radius:10px;background:#fff;text-align:left}.quiz-option.correct{border-color:#6c9b73;background:#edf7ee}.quiz-option.wrong{border-color:#c98a83;background:#fff0ef}.quiz-feedback{min-height:24px;margin-top:10px;font-weight:700}.complete-button{display:inline-flex;margin-top:24px;padding:12px 17px;border:0;border-radius:12px;background:var(--green);color:#fff;font-weight:800}.complete-button.is-done{background:#e4efe4;color:var(--green)}
.glossary{margin-top:28px;padding:24px;border:1px solid var(--line);border-radius:20px;background:#fff}.section-heading{display:grid;grid-template-columns:minmax(0,1fr) 260px;gap:20px;align-items:end}.section-heading h2{margin:0;font-size:2rem}.glossary-grid{display:grid;grid-template-columns:repeat(2,minmax(0,1fr));gap:10px;margin-top:20px}.term{padding:14px 16px;border-radius:12px;background:var(--bg)}.term strong{display:block;margin-bottom:4px}.term span{color:var(--muted);line-height:1.45}
.empty{grid-column:1/-1;padding:30px;border:1px dashed var(--line);border-radius:14px;text-align:center;color:var(--muted)}
@media(max-width:820px){.hero{grid-template-columns:1fr}.progress-card{width:100%}.module-grid{grid-template-columns:repeat(2,minmax(0,1fr))}.toolbar{grid-template-columns:1fr}.section-heading{grid-template-columns:1fr}}
@media(max-width:560px){.electricity-app{padding-bottom:18px}.hero{padding:24px 20px;border-radius:18px}.module-grid{grid-template-columns:1fr}.module-card{min-height:210px}.glossary{padding:18px}.glossary-grid{grid-template-columns:1fr}.lesson article{padding:22px 18px;border-radius:18px}.lesson table{font-size:.86rem}.lesson th,.lesson td{padding:8px}}