:root {
  --bg: #ffffff;
  --bg-soft: #f8fafc;
  --card: #ffffff;
  --card-strong: #f8fafc;
  --text: #0f172a;
  --muted: #475569;
  --accent: #f59e0b;
  --accent-2: #22c55e;
  --line: rgba(15, 23, 42, 0.10);
  --shadow: 0 18px 50px rgba(15, 23, 42, 0.08);
}

* { box-sizing: border-box; }
html { scroll-behavior: smooth; }
body {
  margin: 0;
  font-family: Inter, system-ui, sans-serif;
  background: var(--bg);
  color: var(--text);
}

a { color: inherit; text-decoration: none; }

.hero {
  padding: 1.2rem clamp(1rem, 3vw, 3rem) 4rem;
}

.topbar {
  display: flex;
  justify-content: space-between;
  align-items: center;
  gap: 1rem;
  margin-bottom: 3rem;
}

.brand {
  font-weight: 800;
  letter-spacing: 0.06em;
  text-transform: lowercase;
}

.nav-links {
  display: flex;
  gap: 1rem;
  flex-wrap: wrap;
  color: var(--muted);
}

.hero-content {
  display: grid;
  grid-template-columns: 1.6fr 1fr;
  gap: 2rem;
  align-items: start;
}

.eyebrow {
  text-transform: uppercase;
  letter-spacing: 0.18em;
  font-size: 0.75rem;
  color: var(--accent);
  margin-bottom: 0.75rem;
}

h1, h2, h3, p { margin-top: 0; }
h1 {
  font-size: clamp(2.4rem, 5vw, 4.6rem);
  line-height: 1;
  margin-bottom: 1rem;
}

.lead {
  max-width: 60ch;
  color: var(--muted);
  font-size: 1.08rem;
}

.hero-card,
.card,
.info-card,
.note-card {
  background: var(--card);
  border: 1px solid var(--line);
  border-radius: 24px;
  padding: 1.35rem;
  box-shadow: var(--shadow);
}

.hero-actions {
  display: flex;
  gap: 1rem;
  margin-top: 1.5rem;
  flex-wrap: wrap;
}

.button {
  border-radius: 999px;
  padding: 0.9rem 1.2rem;
  font-weight: 700;
}

.button.primary {
  background: linear-gradient(135deg, var(--accent), #fb7185);
  color: #111827;
}

.button.ghost {
  border: 1px solid var(--line);
  color: var(--text);
  background: #ffffff;
}

.section {
  padding: 0 clamp(1rem, 3vw, 3rem) 4rem;
}

.section-head {
  max-width: 70ch;
  margin-bottom: 1.4rem;
}

.contrast {
  background: #f8fafc;
  padding-top: 3.5rem;
}

.card-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(260px, 1fr));
  gap: 1rem;
}

.card-top {
  display: flex;
  justify-content: space-between;
  gap: 1rem;
  align-items: center;
}

.tag {
  font-size: 0.8rem;
  color: #0b1220;
  background: #dcfce7;
  padding: 0.35rem 0.65rem;
  border-radius: 999px;
  font-weight: 700;
}

.diagram {
  display: grid;
  gap: 0.5rem;
  margin: 1rem 0;
}

.string-row {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 1rem;
  padding-bottom: 0.45rem;
  border-bottom: 1px solid rgba(15,23,42,0.08);
}

.string-name { color: var(--muted); }

.fret-mark {
  min-width: 2rem;
  text-align: center;
  padding: 0.3rem 0.55rem;
  border-radius: 999px;
  font-weight: 700;
}

.fret-mark.open { background: #1d4ed8; }
.fret-mark.pressed { background: #16a34a; }
.fret-mark.mute { background: #b91c1c; }

.finger-list {
  padding-left: 1.15rem;
  color: var(--muted);
}

.tip {
  margin-top: 1rem;
  color: #1e293b;
}

.notes-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(180px, 1fr));
  gap: 1rem;
}

.theory-block {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
  gap: 1rem;
  margin-top: 1.25rem;
}

.theory-block ul {
  margin: 0.75rem 0 0;
  padding-left: 1.2rem;
  color: var(--muted);
}

.theory-block li {
  margin-bottom: 0.4rem;
}

.note-card h3 {
  font-size: 1.4rem;
  margin-bottom: 0.5rem;
}

.scale-layout {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(260px, 1fr));
  gap: 1rem;
}

.scale-strip {
  margin-top: 1.4rem;
  display: grid;
  grid-template-columns: repeat(8, minmax(0, 1fr));
  gap: 0.6rem;
}

.scale-note {
  background: var(--card-strong);
  border: 1px solid var(--line);
  padding: 1rem 0.4rem;
  border-radius: 18px;
  text-align: center;
  font-weight: 800;
  color: var(--text);
}

.scale-note.tonic {
  background: linear-gradient(135deg, #f59e0b, #ef4444);
  color: #111827;
}

.practice-list {
  display: grid;
  gap: 1rem;
}

.practice-step {
  display: grid;
  grid-template-columns: 64px 1fr;
  gap: 1rem;
  align-items: start;
  background: var(--card);
  border: 1px solid var(--line);
  border-radius: 20px;
  padding: 1rem;
}

.practice-step span {
  width: 48px;
  height: 48px;
  display: grid;
  place-items: center;
  border-radius: 50%;
  background: var(--accent);
  color: #111827;
  font-weight: 800;
}

.footer {
  padding: 2rem 1rem 3rem;
  text-align: center;
  color: var(--muted);
}

.muted { color: var(--muted); }

@media (max-width: 900px) {
  .hero-content { grid-template-columns: 1fr; }
  .topbar { flex-direction: column; align-items: flex-start; }
}

@media (max-width: 640px) {
  .scale-strip { grid-template-columns: repeat(4, minmax(0, 1fr)); }
}