:root{
  --bg:#0e0f12; --panel:#181a20; --card:#20232b; --text:#f5f5f4;
  --muted:#aaaeb9; --border:#353944; --accent:#d9b24c; --accent2:#f0d57c;
}
*{box-sizing:border-box}
body{margin:0;background:linear-gradient(180deg,#0d0e11,#13151a);color:var(--text);font-family:Inter,ui-sans-serif,system-ui,-apple-system,BlinkMacSystemFont,"Segoe UI",sans-serif}
button,select,input{font:inherit}
button,select{min-height:46px;border-radius:12px;border:1px solid var(--border);background:#14161b;color:var(--text);padding:0 14px}
button{cursor:pointer;font-weight:700}
button:hover{border-color:#666c79}
button:focus,select:focus,input:focus{outline:3px solid rgba(217,178,76,.35);outline-offset:2px}
.primary{background:var(--accent);color:#111;border-color:var(--accent)}
.shell{max-width:980px;margin:auto;padding:24px}
.hero{padding:18px 0 8px}
.brand{display:flex;gap:18px;align-items:center}
.logo{width:72px;height:72px}
h1{font-size:clamp(2rem,6vw,3.4rem);margin:.1rem 0}
h2{margin:.15rem 0 0;font-size:1.35rem}
h3{margin:.2rem 0 .65rem}
p{line-height:1.55}
.eyebrow{margin:0;color:var(--accent2);font-size:.75rem;letter-spacing:.15em;font-weight:800}
.tagline{margin:.2rem 0;color:var(--accent2);font-weight:700}
.intro{color:var(--muted);max-width:760px}
.panel{background:var(--panel);border:1px solid var(--border);border-radius:20px;padding:18px}
.controls{display:grid;grid-template-columns:repeat(4,1fr);gap:12px}
.controls label{display:flex;flex-direction:column;gap:8px;font-size:.86rem;font-weight:700;color:var(--muted)}
.tempo-row{display:flex;align-items:center;gap:10px;min-height:46px}
.tempo-row input{width:100%}
.section-heading{display:flex;justify-content:space-between;align-items:end;gap:12px;margin:26px 0 12px}
.cards{display:grid;grid-template-columns:repeat(3,1fr);gap:12px}
.chord-card{text-align:left;background:var(--card);border:1px solid var(--border);border-radius:18px;padding:17px}
.chord-name{font-size:2.1rem;font-weight:850;margin:.2rem 0}
.notes{color:var(--muted);font-size:.92rem}
.two-col{display:grid;grid-template-columns:1fr 1fr;gap:24px}
.button-row{display:flex;flex-wrap:wrap;gap:8px}
.inv.active{background:var(--accent);color:#111;border-color:var(--accent)}
.help{color:var(--muted);font-size:.92rem}
.keyboard-wrap{overflow-x:auto;padding-bottom:4px}
.keyboard{position:relative;height:155px;min-width:650px}
.white-key{position:absolute;top:0;height:100%;border:1px solid #6f7480;background:#f3f3ee;color:#111;display:flex;align-items:flex-end;justify-content:center;padding-bottom:9px;border-radius:0 0 8px 8px}
.white-key.hit{background:#f4d97f}
.black-key{position:absolute;z-index:2;top:0;height:62%;background:#111;border:1px solid #444;border-radius:0 0 7px 7px}
.black-key.hit{background:var(--accent)}
.bars{display:grid;grid-template-columns:repeat(8,1fr);gap:8px}
.bar{background:var(--card);border:1px solid var(--border);border-radius:14px;padding:9px}
.bar label{display:block;color:var(--muted);font-size:.72rem;font-weight:800;margin-bottom:5px}
.bar select{width:100%;padding:0 8px}
.bottom-actions{margin-top:12px}
.lesson-grid{display:grid;grid-template-columns:repeat(3,1fr);gap:12px;margin-top:13px}
.lesson-grid>div{background:var(--card);border-radius:14px;padding:14px}
.lesson-grid p{margin:.3rem 0;color:var(--muted);font-size:.9rem}
.tip{border-left:4px solid var(--accent);padding-left:12px}
footer{display:flex;flex-wrap:wrap;justify-content:space-between;gap:8px;color:var(--muted);border-top:1px solid var(--border);padding:22px 0 8px;margin-top:26px}
@media(max-width:720px){
  .shell{padding:16px}
  .controls,.cards,.two-col,.lesson-grid{grid-template-columns:1fr}
  .bars{grid-template-columns:repeat(2,1fr)}
  .section-heading{align-items:flex-start;flex-direction:column}
  .brand{align-items:flex-start}
}