:root {
  --bg: #07080c;
  --panel: #0d1018;
  --panel-2: #121622;
  --text: #e8ecf4;
  --muted: #6f7891;
  --line: #1d2433;          /* parade border */
  --neon: #36e0ff;          /* default neon edge */
  --root-w: 9vw;
}
* { box-sizing: border-box; margin: 0; padding: 0; }
html, body { height: 100%; }
body {
  font-family: "Segoe UI", system-ui, -apple-system, Roboto, sans-serif;
  background:
    radial-gradient(140% 120% at 50% -10%, #0f1422 0%, var(--bg) 55%),
    repeating-linear-gradient(0deg, rgba(54,224,255,.025) 0 2px, transparent 2px 4px); /* lofi scanline */
  color: var(--text);
  line-height: 1.35;
  overflow: hidden;
  letter-spacing: .02em;
}

/* ---- overall frame: a bordered console ---- */
.app {
  height: 100vh;
  width: 100vw;
  display: flex;
  gap: 1vw;
  padding: 1.2vh 1vw;
  border: 1px solid var(--line);
}

/* ---- left: rainbow root column, framed ---- */
.roots {
  flex: 0 0 var(--root-w);
  height: 100%;
  border: 1px solid var(--line);
  border-radius: 12px;
  padding: .5vh .4vw;
  background: linear-gradient(180deg, var(--panel), var(--panel-2));
}
.root-col {
  height: 100%;
  display: flex;
  flex-direction: column;
  gap: .5vh;
}
button.chord-btn.root {
  flex: 1 1 0;
  border: 1px solid rgba(255,255,255,.18);
  border-radius: 9px;
  font-size: clamp(.85rem, 1.6vw, 1.5rem);
  font-weight: 800;
  color: #06070a;
  cursor: pointer;
  display: flex; align-items: center; justify-content: center;
  text-shadow: 0 1px 0 rgba(255,255,255,.25);
  box-shadow: 0 0 10px rgba(0,0,0,.4), inset 0 0 8px rgba(255,255,255,.12);
  transition: transform .06s ease, filter .12s ease, box-shadow .15s ease;
}
button.chord-btn.root:hover { filter: brightness(1.15); }
button.chord-btn.root:active { transform: scale(.93); }
button.chord-btn.root.active {
  box-shadow: 0 0 0 2px rgba(255,255,255,.7), 0 0 18px var(--gc, #fff);
  filter: brightness(1.25);
}

/* ---- right stage ---- */
.stage {
  flex: 1 1 auto;
  height: 100%;
  display: flex;
  flex-direction: column;
  min-width: 0;
  gap: 1vh;
}

/* ---- diagram stage: ABOVE buttons, smaller, black, framed, fade-in ---- */
.diagram-box {
  flex: 0 0 30vh;
  display: flex;
  justify-content: center;
  align-items: stretch;
}
.diagram-stage {
  width: 30vh;
  max-width: 100%;
  background: #000;
  border: 1px solid var(--line);
  border-radius: 14px;
  box-shadow: 0 0 30px rgba(54,224,255,.08), inset 0 0 40px rgba(0,0,0,.9);
  display: flex; align-items: center; justify-content: center;
  overflow: hidden;
}
#diagramImg {
  max-width: 90%;
  max-height: 90%;
  height: auto; width: auto;
  border-radius: 4px;
  opacity: 0;
  transition: opacity .5s ease;
  filter: drop-shadow(0 0 10px rgba(54,224,255,.12));
}
#diagramImg.show { opacity: 1; }

/* chord grid below the diagram */
.chords {
  flex: 1 1 auto;
  min-height: 0;
  border: 1px solid var(--line);
  border-radius: 12px;
  padding: .6vh .5vw;
  background: linear-gradient(180deg, var(--panel), var(--panel-2));
  display: flex;
}
.chord-grid {
  flex: 1 1 auto;
  display: grid;
  gap: .5vh .4vw;
  align-content: stretch;
}
.chord-grid .spacer {
  border: 1px solid var(--line);
  border-left: 3px solid var(--line);
  background: linear-gradient(180deg, #11151f, #0c0f17);
  color: var(--muted);
  cursor: pointer;
  opacity: .5;
}
.chord-grid .spacer:hover { box-shadow: none; background: linear-gradient(180deg, #11151f, #0c0f17); }
.chord-grid button {
  border: 1px solid var(--line);
  border-left: 3px solid var(--bc, var(--neon));
  border-radius: 8px;
  background: linear-gradient(180deg, #11151f, #0c0f17);
  color: var(--text);
  font-size: clamp(.6rem, 1.15vw, 1rem);
  font-weight: 600;
  cursor: pointer;
  padding: .15rem .25rem;
  display: flex; align-items: center; justify-content: center;
  text-align: center;
  letter-spacing: .01em;
  text-shadow: 0 0 6px rgba(54,224,255,.18);
  transition: transform .06s ease, box-shadow .15s ease, background .15s ease, color .15s ease;
  overflow: hidden;
}
.chord-grid button:hover {
  background: linear-gradient(180deg, #161c2a, #10141e);
  box-shadow: 0 0 10px rgba(54,224,255,.25);
}
.chord-grid button:active { transform: scale(.95); }
.chord-grid button.active {
  background: var(--bc, var(--neon));
  color: #06070a;
  border-color: #06070a;
  box-shadow: 0 0 14px var(--bc, var(--neon)), 0 0 0 1px rgba(255,255,255,.4);
  text-shadow: none;
}

@media (orientation: portrait) {
  .app::after {
    content: "Best viewed in landscape";
    position: fixed; inset: 0; display: flex; align-items: center; justify-content: center;
    background: var(--bg); color: var(--muted); font-size: 1.2rem; z-index: 9;
  }
}

/* ---- placeholder "?" popup toast ---- */
.toast {
  position: fixed;
  left: 50%; bottom: 4vh;
  transform: translateX(-50%) translateY(20px);
  background: linear-gradient(180deg, #11151f, #0c0f17);
  border: 1px solid var(--neon);
  color: var(--text);
  padding: .7rem 1.2rem;
  border-radius: 10px;
  font-size: clamp(.8rem, 1.4vw, 1rem);
  letter-spacing: .03em;
  box-shadow: 0 0 22px rgba(54,224,255,.35);
  opacity: 0;
  pointer-events: none;
  transition: opacity .25s ease, transform .25s ease;
  z-index: 20;
}
.toast.show {
  opacity: 1;
  transform: translateX(-50%) translateY(0);
}

/* ---- first-load onboarding pointing at root column ---- */
.onboard {
  position: fixed;
  inset: 0;
  z-index: 30;
  display: flex;
  align-items: center;
  justify-content: flex-start;
  padding-left: calc(var(--root-w) + 2vw);
  background: rgba(4,5,8,.55);
  backdrop-filter: blur(2px);
  transition: opacity .35s ease;
}
.onboard.hide { opacity: 0; pointer-events: none; }
.onboard-card {
  max-width: 320px;
  background: linear-gradient(180deg, #11151f, #0c0f17);
  border: 1px solid var(--neon);
  border-radius: 14px;
  padding: 1.1rem 1.3rem;
  box-shadow: 0 0 30px rgba(54,224,255,.3);
}
.onboard-card h2 {
  margin: 0 0 .5rem;
  font-size: 1.25rem;
  color: var(--neon);
  text-shadow: 0 0 10px rgba(54,224,255,.5);
}
.onboard-card p {
  margin: 0 0 .9rem;
  color: var(--text);
  font-size: .95rem;
  line-height: 1.45;
}
.onboard-card b { color: #fff; }
.onboard-ok {
  background: var(--neon);
  color: #06070a;
  border: none;
  border-radius: 8px;
  padding: .5rem 1.1rem;
  font-weight: 700;
  cursor: pointer;
  font-size: .9rem;
}
.onboard-ok:hover { filter: brightness(1.1); }
.onboard-arrow {
  font-size: clamp(3rem, 7vw, 6rem);
  color: var(--neon);
  margin-right: 1.5vw;
  text-shadow: 0 0 18px rgba(54,224,255,.6);
  animation: nudge 1.1s ease-in-out infinite;
}
@keyframes nudge {
  0%, 100% { transform: translateX(0); }
  50% { transform: translateX(-14px); }
}

/* ---- ad slot (defined space so layout never jumps) ---- */
.ad-slot {
  flex: 0 0 auto;
  min-height: 90px;
  margin: 0 0 1vh;
  display: flex;
  align-items: center;
  justify-content: center;
  border: 1px dashed var(--line);
  border-radius: 10px;
  background: rgba(255,255,255,.02);
  overflow: hidden;
}
.ad-placeholder {
  color: var(--muted);
  font-size: .8rem;
  letter-spacing: .04em;
  padding: .6rem;
  text-align: center;
}

/* ---- consent gate (bottom banner) ---- */
.consent {
  position: fixed;
  left: 0; right: 0; bottom: 0;
  z-index: 40;
  display: flex;
  justify-content: center;
  padding: 1.2vh 1vw;
  background: linear-gradient(0deg, rgba(4,5,8,.92), rgba(4,5,8,.55));
  transition: opacity .3s ease, transform .3s ease;
}
.consent.hide { opacity: 0; transform: translateY(100%); pointer-events: none; }
.consent-card {
  max-width: 640px;
  width: 100%;
  background: linear-gradient(180deg, #11151f, #0c0f17);
  border: 1px solid var(--neon);
  border-radius: 12px;
  padding: .9rem 1.1rem;
  box-shadow: 0 0 26px rgba(54,224,255,.28);
  display: flex;
  align-items: center;
  gap: 1rem;
  flex-wrap: wrap;
}
.consent-card p {
  flex: 1 1 240px;
  margin: 0;
  color: var(--text);
  font-size: .85rem;
  line-height: 1.4;
}
.consent-btns { display: flex; gap: .6rem; }
.consent-accept, .consent-reject {
  border: none; border-radius: 8px; padding: .5rem 1rem;
  font-weight: 700; cursor: pointer; font-size: .85rem;
}
.consent-accept { background: var(--neon); color: #06070a; }
.consent-reject { background: transparent; color: var(--muted); border: 1px solid var(--line); }
.consent-accept:hover { filter: brightness(1.1); }

/* ---- standalone legal / privacy page ---- */
.legal {
  max-width: 720px;
  margin: 6vh auto;
  padding: 0 1.2rem;
  line-height: 1.6;
}
.legal h1 { font-size: 1.8rem; margin-bottom: .3rem; }
.legal h2 { font-size: 1.1rem; margin: 1.6rem 0 .4rem; color: var(--neon); }
.legal p { color: var(--text); margin: .4rem 0; }
.legal a { color: var(--neon); }