/* Fretwise — built on the Justin Horner design system.
   Graphite, Bone and Steel, with Tube Amber reserved for the note you're looking at. */

:root {
  --ground: #111214;
  --surface: #2A2D33;
  --ink: #ECE7DF;
  --muted: #9AA1AB;
  --line: #3B3F47;
  --accent: #F28C28;
  --on-accent: #111214;
  --accent-text: #F28C28;
  --focus: #F28C28;
  /* fretboard */
  --board: #2A2D33;
  --board-dim: #1B1D21;
  --fret: #4A4F58;
  --string: #8B929C;
  --nut: #ECE7DF;
  --ring: #5A5F68;

  --font-display: "Barlow Condensed", "Arial Narrow", sans-serif;
  --font-body: Barlow, "Helvetica Neue", Arial, sans-serif;
  --font-mono: "JetBrains Mono", ui-monospace, Menlo, monospace;
  --space-1: 8px; --space-2: 16px; --space-3: 32px; --space-4: 64px;
  --radius-1: 4px; --radius-2: 8px;
  color-scheme: dark;
}
@media (prefers-color-scheme: light) {
  :root {
    --ground: #F4F0E9;
    --surface: #E6E0D6;
    --ink: #16171A;
    --muted: #565C65;
    --line: #CFC8BC;
    --accent-text: #964808;
    --focus: #964808;
    --board: #E6E0D6;
    --board-dim: #EEE9E1;
    --fret: #B3AA9C;
    --string: #6B717A;
    --nut: #16171A;
    --ring: #9D958A;
    color-scheme: light;
  }
}

*, *::before, *::after { box-sizing: border-box; }
html { -webkit-text-size-adjust: 100%; }
body {
  margin: 0; background: var(--ground); color: var(--ink);
  font: 400 17px/26px var(--font-body);
}
a { color: var(--accent-text); }
:focus-visible { outline: 2px solid var(--focus); outline-offset: 2px; }
h1, h2, h3 { font-family: var(--font-display); margin: 0; }
h1 { font-weight: 800; font-size: clamp(48px, 8vw, 88px); line-height: .9; text-transform: uppercase; }
h1:focus { outline: none; }
h2 { font-weight: 700; font-size: 28px; line-height: 1.1; }
h3 { font-weight: 700; font-size: 22px; line-height: 1.15; }
p { margin: 0; }
.muted { color: var(--muted); }
.small { font-size: 14px; line-height: 20px; font-weight: 500; }
.tag { font: 500 13px/16px var(--font-mono); letter-spacing: .08em; text-transform: uppercase; color: var(--muted); }
.lbl { font-size: 14px; line-height: 20px; font-weight: 500; color: var(--muted); }
.mono-sm { font: 500 12px/1 var(--font-mono); color: var(--muted); }

.skip { position: absolute; left: -9999px; top: 8px; background: var(--ink); color: var(--ground); padding: 8px 16px; border-radius: var(--radius-1); z-index: 10; }
.skip:focus { left: 16px; }

/* ---------- header ---------- */
.site {
  display: flex; align-items: center; flex-wrap: wrap; gap: 12px 40px;
  padding: 20px 32px; border-bottom: 1px solid var(--line);
}
.brand { display: flex; align-items: center; gap: 12px; text-decoration: none; color: var(--ink); }
.brand img { display: block; }
@media (prefers-color-scheme: light) { .brand img { filter: invert(1); } } /* dark disc on light pages */
.brand span { font: 800 28px/1 var(--font-display); letter-spacing: .04em; text-transform: uppercase; }
.site nav { display: flex; flex-wrap: wrap; gap: 8px 28px; }
.nav {
  font: 500 13px/1 var(--font-mono); letter-spacing: .08em; text-transform: uppercase;
  color: var(--ink); text-decoration: none; padding: 14px 0 10px; border-bottom: 2px solid transparent;
}
.nav:hover { border-color: var(--muted); }
.nav[aria-current="page"] { border-color: var(--ink); }
.back { margin-left: auto; }

/* ---------- layout ---------- */
.wrap { max-width: 1240px; margin: 0 auto; padding: 64px 32px; display: flex; flex-direction: column; gap: 40px; }
main:focus { outline: none; }
.site-foot { padding-top: 0; padding-bottom: 48px; }
.hero { display: flex; flex-direction: column; gap: 16px; max-width: 780px; }
.lede { font-size: 19px; line-height: 29px; color: var(--muted); }
.stack { display: flex; flex-direction: column; gap: 24px; }
.stack-sm { display: flex; flex-direction: column; gap: 12px; }
.row { display: flex; flex-wrap: wrap; gap: 8px; }
.field { display: flex; flex-direction: column; gap: 10px; }
.controls { display: flex; flex-wrap: wrap; align-items: flex-end; justify-content: space-between; gap: 24px; }
.controls.col { flex-direction: column; align-items: stretch; gap: 20px; }
.controls-row, .controls-end { display: flex; flex-wrap: wrap; align-items: flex-end; gap: 20px 40px; }
.controls-end { gap: 16px 24px; }

/* ---------- buttons ---------- */
.btn, .nb {
  font: 500 15px/1 var(--font-body); min-height: 44px; padding: 0 18px;
  border-radius: var(--radius-1); border: 1px solid var(--line); background: transparent; color: var(--ink);
  cursor: pointer; display: inline-flex; align-items: center; justify-content: center; gap: 8px; text-decoration: none;
}
.nb { font: 700 20px/1 var(--font-display); min-width: 52px; height: 48px; padding: 0 10px; }
.nb.lg { font-size: 24px; min-width: 64px; height: 56px; }
.btn:hover, .nb:hover { border-color: var(--muted); }
.btn[aria-pressed="true"], .nb[aria-pressed="true"], .btn.on, .nb.on { background: var(--ink); color: var(--ground); border-color: var(--ink); }
.nb.wrong { border-style: dashed; color: var(--muted); text-decoration: line-through; }
[aria-disabled="true"] { cursor: default; }

/* ---------- fretboard (sideways) ---------- */
.board-sec { display: flex; flex-direction: column; gap: 20px; }
.board-scroll { overflow-x: auto; }
.fb, .fn { display: grid; }
.c, .v { position: relative; display: flex; align-items: center; justify-content: center; background: var(--board); }
.c { height: 46px; border-right: 2px solid var(--fret); }
.c.open { background: var(--ground); border-right: 6px solid var(--nut); }
.c.dim, .v.dim { background: var(--board-dim); }
.c.open.dim, .v.open.dim { background: var(--ground); }
.c::before { content: ""; position: absolute; left: 0; right: 0; top: 50%; height: 1px; background: var(--string); }
.c.s0::before { height: 3px; margin-top: -1px; }
.c.s1::before { height: 2.5px; margin-top: -1px; }
.c.s2::before { height: 2px; }
.c.s3::before { height: 1.5px; }
.fn span { font: 500 12px/1 var(--font-mono); color: var(--muted); text-align: center; padding-top: 12px; }
.fn span.in { color: var(--ink); }

/* ---------- fretboard (upright, phones) ---------- */
.fv { display: grid; grid-template-columns: 24px repeat(6, minmax(0, 1fr)); }
.v { height: 40px; border-bottom: 2px solid var(--fret); }
.v.open { background: var(--ground); border-bottom: 5px solid var(--nut); }
.v::before { content: ""; position: absolute; top: 0; bottom: 0; left: 50%; width: 1px; background: var(--string); }
.v.s0::before { width: 3px; margin-left: -1px; }
.v.s1::before { width: 2.5px; margin-left: -1px; }
.v.s2::before { width: 2px; }
.v.s3::before { width: 1.5px; }
.vn { font: 500 11px/1 var(--font-mono); color: var(--muted); display: flex; align-items: center; }
.vn.in { color: var(--ink); }

/* ---------- note marks ---------- */
.mk {
  position: relative; z-index: 1; width: 32px; height: 32px; border-radius: 50%;
  display: flex; align-items: center; justify-content: center; font: 600 14px/1 var(--font-body);
}
.mk-root { background: var(--accent); color: var(--on-accent); }
.mk-tone { background: var(--ink); color: var(--ground); }
.mk-ghost { background: var(--ground); color: var(--muted); box-shadow: inset 0 0 0 1px var(--ring); }
.mk.ping { animation: ping .3s ease-out; }
@keyframes ping { 50% { transform: scale(1.25); } }
.hit { position: absolute; inset: 0; z-index: 2; background: transparent; border: 0; cursor: pointer; padding: 0; }
.hit:hover { background: color-mix(in srgb, var(--ink) 10%, transparent); }
.hit:focus-visible { outline-offset: -2px; }

.board-foot { display: flex; flex-wrap: wrap; align-items: flex-end; justify-content: space-between; gap: 16px; }
.where { display: grid; grid-template-columns: repeat(auto-fit, minmax(150px, 1fr)); gap: 16px; margin: 0; border-top: 1px solid var(--line); padding-top: 24px; }
.where dt { font-size: 14px; line-height: 20px; font-weight: 500; color: var(--muted); }
.where dd { margin: 4px 0 0; font: 700 22px/1.1 var(--font-display); }

/* ---------- cards ---------- */
.cards { display: grid; grid-template-columns: repeat(auto-fit, minmax(210px, 1fr)); gap: 16px; }
.cards.two { grid-template-columns: repeat(auto-fit, minmax(min(340px, 100%), 1fr)); align-items: start; }
.card { background: var(--surface); border-radius: var(--radius-2); padding: 24px; display: flex; flex-direction: column; gap: 8px; }
.card.pad { padding: 32px; gap: 16px; }
.card .big { font: 800 32px/1 var(--font-display); }
.card p { font-size: 15px; line-height: 23px; color: var(--muted); }
.card .list { margin: 0; padding-left: 20px; display: flex; flex-direction: column; gap: 10px; font-size: 16px; line-height: 24px; }

.chip { display: inline-flex; flex-direction: column; align-items: center; gap: 4px; min-width: 44px; padding: 8px 6px; border: 1px solid var(--line); border-radius: var(--radius-1); }
.chip b { font: 700 22px/1 var(--font-display); }
.chip small { font-size: 13px; line-height: 16px; color: var(--muted); }
.chip.big { min-width: 52px; padding: 10px 8px; }
.chip.big b { font-size: 26px; }
.steps, .formula { list-style: none; margin: 0; padding: 0; display: flex; flex-wrap: wrap; align-items: center; gap: 8px; }
.steps li { display: inline-flex; align-items: center; gap: 8px; }
.gap { font-size: 13px; line-height: 16px; font-weight: 500; color: var(--muted); }

/* ---------- chord shapes ---------- */
.shapes { display: flex; flex-wrap: wrap; gap: 12px; }
.shape {
  background: transparent; border: 1px solid var(--line); border-radius: var(--radius-2); padding: 16px 18px;
  cursor: pointer; display: flex; flex-direction: column; align-items: center; gap: 10px; color: var(--ink);
}
.shape:hover { border-color: var(--muted); }
.shape[aria-pressed="true"] { border-color: var(--ink); box-shadow: inset 0 0 0 1px var(--ink); }
.dg { display: grid; grid-template-columns: repeat(5, 20px) 1px; padding: 0 8px; }
.dt { height: 18px; display: flex; align-items: center; justify-content: center; font: 500 12px/1 var(--font-mono); color: var(--muted); transform: translateX(-50%); }
.dc { height: 22px; position: relative; border-left: 1px solid var(--string); border-bottom: 1px solid var(--string); }
.dc.nut { border-top: 4px solid var(--nut); }
.dc i { position: absolute; left: -7px; top: 4px; width: 12px; height: 12px; border-radius: 50%; background: var(--ink); }
.dc i.r { background: var(--accent); }

/* ---------- practice ---------- */
.nb.str { flex-direction: column; gap: 2px; min-width: 48px; height: 52px; }
.nb.str small { font: 500 11px/1 var(--font-mono); opacity: .8; }
.row-gap { width: 8px; }
.practice-head { display: flex; flex-direction: column; gap: 12px; }
.practice-head h1 { font-size: clamp(40px, 6vw, 72px); }
.answer-sec { gap: 20px; min-height: 140px; }
.feedback-row { align-items: center; gap: 16px; min-height: 48px; }
.feedback { font: 700 28px/1.1 var(--font-display); }
.stats { display: grid; grid-template-columns: repeat(auto-fit, minmax(180px, 1fr)); gap: 16px; align-items: end; border-top: 1px solid var(--line); padding-top: 32px; }
.stats div { display: flex; flex-direction: column; gap: 6px; }
.stats b { font: 800 44px/1 var(--font-display); }
.stats-end { align-items: flex-start; }

/* ---------- call to action / pager ---------- */
.cta, .pager { display: flex; flex-wrap: wrap; align-items: center; justify-content: space-between; gap: 24px; border-top: 1px solid var(--line); padding-top: 40px; }
.cta h2 { font-size: 36px; }
.cta > div:first-child { display: flex; flex-direction: column; gap: 6px; }
.pager { padding-top: 32px; gap: 12px; }

/* ---------- phones ---------- */
@media (max-width: 640px) {
  .site { padding: 14px 16px 0; gap: 4px 24px; }
  .brand img { width: 36px; height: 36px; }
  .brand span { font-size: 24px; }
  .site nav { order: 3; width: 100%; gap: 0 20px; }
  .nav { font-size: 12px; }
  .back { order: 2; font-size: 12px; }
  .wrap { padding: 32px 16px; gap: 32px; }
  .site-foot { padding-top: 0; }
  .lede { font-size: 17px; line-height: 26px; }
  .card.pad { padding: 20px 16px; }
  .answers { display: grid; grid-template-columns: repeat(6, minmax(0, 1fr)); gap: 6px; }
  .nb.lg { min-width: 0; height: 48px; font-size: 22px; }
  .feedback { font-size: 22px; }
  .practice-opts { order: 3; }
  .stats { order: 4; }
  .answer-sec { min-height: 0; }
}
@media (prefers-reduced-motion: reduce) { .mk.ping { animation: none; } }
.shape-name { font: 700 18px/1 var(--font-display); }