:root {
  --bg: #f6f4ef; --panel: #fffefb; --ink: #1f1b16; --muted: #6b6258; --line: #ddd6c9;
  --accent: #c2410c; --accent-ink: #fff; --accent-soft: #fde8dc; --teal: #0f766e; --warn: #b45309;
  --dot: #1f1b16; --shadow: 0 1px 2px rgba(31, 27, 22, .08), 0 4px 14px rgba(31, 27, 22, .05);
  color-scheme: light;
}
@media (prefers-color-scheme: dark) {
  :root {
    --bg: #15120f; --panel: #1e1a16; --ink: #f1ebe2; --muted: #a39a8d; --line: #3a332b;
    --accent: #f08a4b; --accent-ink: #1b0f06; --accent-soft: #3a2316; --teal: #4fd1c5; --warn: #f0b04b;
    --dot: #f1ebe2; --shadow: none; color-scheme: dark;
  }
}
* { box-sizing: border-box; }
body { margin: 0; background: var(--bg); color: var(--ink); font: 15px/1.5 system-ui, -apple-system, "Segoe UI", Roboto, sans-serif; }
.top { display: flex; align-items: center; gap: 20px; padding: 12px 24px; background: var(--panel); border-bottom: 1px solid var(--line); position: sticky; top: 0; z-index: 5; flex-wrap: wrap; }
.brand { display: flex; align-items: center; gap: 10px; }
.brand h1 { font-size: 20px; margin: 0; letter-spacing: -.02em; }
.logo { width: 24px; height: 24px; border-radius: 6px; background: var(--accent); display: inline-block; position: relative; }
.logo::after { content: ""; position: absolute; inset: 5px 6px; border-left: 2px solid #fff; border-right: 2px solid #fff; box-shadow: inset 0 0 0 0 #fff; }
nav { display: flex; gap: 4px; flex: 1; flex-wrap: wrap; }
nav button { background: none; border: 0; padding: 8px 14px; border-radius: 8px; font: inherit; color: var(--muted); cursor: pointer; font-weight: 600; }
nav button:hover { color: var(--ink); background: var(--bg); }
nav button[aria-current="page"] { background: var(--accent-soft); color: var(--accent); }
main { max-width: 1180px; margin: 0 auto; padding: 24px; }
h2 { font-size: 22px; margin: 0 0 4px; letter-spacing: -.01em; }
h3 { font-size: 13px; text-transform: uppercase; letter-spacing: .08em; color: var(--muted); margin: 26px 0 10px; }
.lede { color: var(--muted); margin: 0 0 18px; max-width: 70ch; }
.panel { background: var(--panel); border: 1px solid var(--line); border-radius: 12px; padding: 16px; box-shadow: var(--shadow); }
.controls { display: flex; flex-wrap: wrap; gap: 12px 16px; align-items: flex-end; }
.field { display: flex; flex-direction: column; gap: 4px; font-size: 12px; color: var(--muted); font-weight: 600; }
.field.grow { flex: 1; min-width: 220px; }
.check { display: flex; align-items: center; gap: 6px; font-size: 14px; color: var(--ink); padding-bottom: 6px; font-weight: 500; }
input[type=text], input[type=number], select { font: inherit; padding: 7px 10px; border: 1px solid var(--line); border-radius: 8px; background: var(--bg); color: var(--ink); min-width: 0; }
input[type=text]:focus, input[type=number]:focus, select:focus, button:focus-visible { outline: 2px solid var(--accent); outline-offset: 1px; }
input[type=number] { width: 80px; }
button { font: inherit; cursor: pointer; }
button.primary { background: var(--accent); color: var(--accent-ink); border: 0; padding: 8px 16px; border-radius: 8px; font-weight: 600; }
button.primary:hover { filter: brightness(1.08); }
button.ghost, button.small { background: none; border: 1px solid var(--line); color: var(--ink); padding: 6px 12px; border-radius: 8px; }
button.small { padding: 3px 9px; font-size: 13px; }
button.ghost:hover, button.small:hover { border-color: var(--accent); color: var(--accent); }
.tones { display: flex; flex-wrap: wrap; gap: 8px; margin: 14px 0 2px; }
.tone { display: inline-flex; flex-direction: column; align-items: center; min-width: 48px; padding: 6px 10px; border-radius: 10px; background: var(--accent-soft); color: var(--ink); font-weight: 700; }
.tone small { font-weight: 500; color: var(--muted); font-size: 11px; }
.tone.optional { background: var(--bg); border: 1px dashed var(--line); }
.grid { display: grid; grid-template-columns: repeat(auto-fill, minmax(168px, 1fr)); gap: 14px; }
.card { background: var(--panel); border: 1px solid var(--line); border-radius: 12px; padding: 10px; display: flex; flex-direction: column; align-items: center; gap: 4px; box-shadow: var(--shadow); }
.card.playing { border-color: var(--accent); box-shadow: 0 0 0 3px var(--accent-soft); }
.card .meta { font-size: 12px; color: var(--muted); text-align: center; }
.card .meta b { color: var(--ink); font-family: ui-monospace, Menlo, monospace; font-size: 13px; }
.card .btns { display: flex; gap: 6px; }
.diagram { width: 100%; max-width: 150px; color: var(--ink); }
.d-title { font: 700 13px system-ui, sans-serif; fill: currentColor; }
.d-grid { stroke: currentColor; stroke-width: 1; opacity: .55; }
.d-nut { fill: currentColor; }
.d-dot { fill: var(--dot); }
.d-barre { fill: var(--dot); opacity: .9; }
.d-finger { font: 700 9px system-ui, sans-serif; fill: var(--bg); }
.d-open { fill: none; stroke: currentColor; stroke-width: 1.4; }
.d-mark { font: 700 13px system-ui, sans-serif; fill: currentColor; }
.d-fret { font: 600 11px system-ui, sans-serif; fill: var(--muted); }
.board { overflow-x: auto; padding: 12px; }
.fretboard { width: 100%; min-width: 760px; color: var(--ink); }
.f-fret { stroke: var(--muted); stroke-width: 1.2; opacity: .6; }
.f-nut { stroke: currentColor; stroke-width: 5; }
.f-string { stroke: var(--muted); }
.f-inlay { fill: var(--line); }
.f-num { font: 600 10px system-ui, sans-serif; fill: var(--muted); }
.f-note circle { fill: var(--teal); }
.f-note.root circle { fill: var(--accent); }
.f-note text { font: 700 10px system-ui, sans-serif; fill: #fff; }
.f-note.dim { opacity: .18; }
.f-window { fill-opacity: .1; stroke-opacity: .6; stroke-width: 1.5; stroke-dasharray: 5 4; }
.f-window-label { font: 700 12px system-ui, sans-serif; }
.chips { display: flex; flex-wrap: wrap; gap: 8px; }
.chip { padding: 4px 12px; border-radius: 999px; border: 1px solid var(--line); background: var(--panel); font-weight: 600; font-size: 14px; }
button.chip:hover { border-color: var(--accent); color: var(--accent); }
.chip.best { background: var(--accent-soft); border-color: var(--accent); }
.chip small { color: var(--muted); font-weight: 500; }
.error { color: #b91c1c; font-weight: 600; }
@media (prefers-color-scheme: dark) { .error { color: #fca5a5; } }
.muted { color: var(--muted); }
.kind { display: inline-block; padding: 1px 8px; border-radius: 999px; font-size: 11px; font-weight: 700; text-transform: uppercase; letter-spacing: .04em; background: var(--bg); border: 1px solid var(--line); }
.kind.secondary-dominant, .kind.tritone-sub { color: var(--accent); border-color: var(--accent); }
.kind.borrowed { color: var(--teal); border-color: var(--teal); }
.kind.chromatic { color: var(--warn); border-color: var(--warn); }
.stat { display: inline-block; margin-right: 18px; }
.stat b { font-size: 20px; }
.answers { display: grid; grid-template-columns: repeat(auto-fill, minmax(150px, 1fr)); gap: 8px; margin-top: 14px; }
.answers button { padding: 10px; border: 1px solid var(--line); background: var(--panel); border-radius: 10px; font-weight: 600; color: var(--ink); }
.answers button:hover:not(:disabled) { border-color: var(--accent); }
.answers button.right { background: #dcfce7; border-color: #16a34a; color: #14532d; }
.answers button.wrong { background: #fee2e2; border-color: #dc2626; color: #7f1d1d; }
table { border-collapse: collapse; width: 100%; font-size: 14px; }
th, td { text-align: left; padding: 6px 10px; border-bottom: 1px solid var(--line); }
th { color: var(--muted); font-size: 12px; text-transform: uppercase; letter-spacing: .06em; }
.row-actions { display: flex; gap: 6px; }
.two { display: grid; grid-template-columns: 1fr 1fr; gap: 16px; }
@media (max-width: 760px) { .two { grid-template-columns: 1fr; } main { padding: 14px; } .top { padding: 10px 14px; } }
#toast { position: fixed; bottom: 20px; left: 50%; transform: translateX(-50%) translateY(20px); background: var(--ink); color: var(--bg); padding: 8px 16px; border-radius: 999px; opacity: 0; transition: .2s; pointer-events: none; font-weight: 600; }
#toast.show { opacity: 1; transform: translateX(-50%); }
.foot { text-align: center; color: var(--muted); font-size: 12px; padding: 24px; }