/* ==========================================================================
   Chord Randomizer — Nathaniel School of Music
   Music studio aesthetic
   ========================================================================== */

@import url('https://fonts.googleapis.com/css2?family=Inter:wght@400;500;600;700;800;900&family=JetBrains+Mono:wght@400;500;700&display=swap');

/* ---------- Tokens ---------- */
:root {
  --bg:           #0b0d11;
  --bg-raised:    #12151b;
  --surface:      #181c25;
  --surface-alt:  #1e2330;
  --border:       #252a38;
  --border-light: #2e3548;

  --text:         #e8ebf2;
  --text-2:       #99a1b3;
  --text-3:       #5c6478;

  --gold:         #d4a84b;
  --gold-dim:     #b08d3a;
  --gold-glow:    rgba(212, 168, 75, 0.10);
  --gold-strong:  rgba(212, 168, 75, 0.20);

  --blue:         #5b8def;
  --blue-glow:    rgba(91, 141, 239, 0.12);
  --green:        #4ade80;
  --green-glow:   rgba(74, 222, 128, 0.12);
  --root:         #e8b44a;

  --cols: 4;
  --radius: 10px;
}

*, *::before, *::after { box-sizing: border-box; margin: 0; }

body {
  background: var(--bg);
  color: var(--text);
  font-family: 'Inter', system-ui, -apple-system, sans-serif;
  font-size: 14px;
  line-height: 1.55;
  -webkit-font-smoothing: antialiased;
}

html, body { overflow-x: hidden; }
img { max-width: 100%; height: auto; display: block; }

/* ==========================================================================
   HERO — cinematic music studio feel, two-column layout
   ========================================================================== */
.hero {
  position: relative;
  background: #08090d;
  overflow: hidden;
}

/* --- Layered background effects --- */
.hero-bg {
  position: absolute;
  inset: 0;
  pointer-events: none;
}

.hero-glow {
  position: absolute;
  border-radius: 50%;
  filter: blur(80px);
  animation: glowPulse 6s ease-in-out infinite alternate;
}

.hero-glow--gold {
  width: 600px;
  height: 500px;
  top: -30%;
  left: 5%;
  background: radial-gradient(ellipse, rgba(212,168,75,0.12), transparent 70%);
  opacity: 0.7;
}

.hero-glow--blue {
  width: 500px;
  height: 450px;
  top: -15%;
  right: 10%;
  background: radial-gradient(ellipse, rgba(108,171,247,0.10), transparent 70%);
  opacity: 0.8;
  animation-delay: 3s;
}

.hero-glow--pink {
  width: 400px;
  height: 350px;
  bottom: -20%;
  right: 30%;
  background: radial-gradient(ellipse, rgba(244,114,182,0.07), transparent 70%);
  opacity: 0.6;
  animation-delay: 5s;
}

@keyframes glowPulse {
  0%   { opacity: 0.5; transform: scale(1); }
  100% { opacity: 0.8; transform: scale(1.08); }
}

.hero-grid-lines {
  position: absolute;
  inset: 0;
  background-image:
    linear-gradient(rgba(255,255,255,0.018) 1px, transparent 1px),
    linear-gradient(90deg, rgba(255,255,255,0.018) 1px, transparent 1px);
  background-size: 50px 50px;
  mask-image: radial-gradient(ellipse 90% 80% at 50% 50%, black, transparent);
  -webkit-mask-image: radial-gradient(ellipse 90% 80% at 50% 50%, black, transparent);
}

/* --- Hero layout --- */
.hero-inner {
  max-width: 1440px;
  margin: 0 auto;
  padding: 20px 28px 0;
  position: relative;
  z-index: 2;
}

.hero-nav {
  display: flex;
  align-items: center;
  justify-content: space-between;
  margin-bottom: 32px;
}

.logo-link { display: flex; align-items: center; }
.logo-img { height: 32px; opacity: 0.9; }
.hero-nav-right { display: flex; align-items: center; gap: 8px; }

/* Centered hero layout */
.hero-center {
  text-align: center;
  max-width: 1000px;
  margin: 0 auto;
  padding-bottom: 40px;
}

.hero-badge {
  display: inline-block;
  font-size: 10px;
  font-weight: 700;
  letter-spacing: 2px;
  text-transform: uppercase;
  color: var(--gold);
  background: var(--gold-glow);
  border: 1px solid var(--gold-strong);
  padding: 4px 12px;
  border-radius: 999px;
  margin-bottom: 20px;
}

.hero h1 {
  font-size: 52px;
  font-weight: 900;
  letter-spacing: -2px;
  line-height: 1.0;
  margin-bottom: 20px;
  background: linear-gradient(160deg, #ffffff 0%, #fff 40%, var(--gold) 100%);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
}

.hero-tagline {
  font-size: 17px;
  color: var(--text-2);
  line-height: 1.7;
  max-width: 680px;
  margin: 0 auto 24px;
}

/* Feature pills */
.hero-features {
  display: flex;
  flex-wrap: wrap;
  justify-content: center;
  gap: 8px;
  margin-bottom: 28px;
}

.feat-pill {
  font-size: 11px;
  font-weight: 600;
  letter-spacing: 0.3px;
  padding: 5px 14px;
  border-radius: 999px;
  border: 1px solid var(--border-light);
  background: rgba(255,255,255,0.03);
  color: var(--text-2);
}

.feat-pill:nth-child(1) { border-color: rgba(212,168,75,0.3); color: #d4a84b; }
.feat-pill:nth-child(2) { border-color: rgba(108,171,247,0.3); color: #6cabf7; }
.feat-pill:nth-child(3) { border-color: rgba(52,211,153,0.3); color: #34d399; }
.feat-pill:nth-child(4) { border-color: rgba(244,114,182,0.3); color: #f472b6; }
.feat-pill:nth-child(5) { border-color: rgba(192,132,252,0.3); color: #c084fc; }
.feat-pill:nth-child(6) { border-color: rgba(212,168,75,0.3); color: #d4a84b; }

/* ==========================================================================
   HERO DEMO — steps + app preview side by side
   ========================================================================== */
.hero-demo {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 40px;
  align-items: center;
  margin-bottom: 24px;
  text-align: left;
}

/* --- How-it-works steps --- */
.hero-steps {
  display: flex;
  flex-direction: column;
  gap: 20px;
}

.step {
  display: flex;
  gap: 14px;
  align-items: flex-start;
}

.step-num {
  flex-shrink: 0;
  width: 28px;
  height: 28px;
  border-radius: 50%;
  border: 1px solid var(--gold-strong);
  background: var(--gold-glow);
  color: var(--gold);
  font-family: 'JetBrains Mono', monospace;
  font-size: 12px;
  font-weight: 800;
  display: flex;
  align-items: center;
  justify-content: center;
}

.step-body {
  display: flex;
  flex-direction: column;
  gap: 3px;
}

.step-body strong {
  font-size: 14px;
  font-weight: 700;
  color: var(--text);
}

.step-body span {
  font-size: 13px;
  color: var(--text-3);
  line-height: 1.5;
}

.step-body kbd {
  font-family: 'JetBrains Mono', monospace;
  background: rgba(255,255,255,0.06);
  border: 1px solid var(--border);
  border-radius: 3px;
  padding: 0 4px;
  font-size: 11px;
  font-weight: 600;
  color: var(--gold);
}

/* --- Styled app preview panel --- */
.hero-preview {
  background: var(--bg-raised);
  border: 1px solid var(--border);
  border-radius: 14px;
  padding: 14px;
  box-shadow: 0 8px 32px rgba(0,0,0,0.3), 0 0 0 1px rgba(255,255,255,0.03) inset;
}

.preview-bar {
  display: flex;
  align-items: center;
  justify-content: space-between;
  margin-bottom: 12px;
  padding: 0 2px;
}

.preview-title {
  font-size: 10px;
  font-weight: 700;
  letter-spacing: 0.8px;
  text-transform: uppercase;
  color: var(--gold);
}

.preview-play {
  font-size: 11px;
  font-weight: 600;
  color: var(--text-3);
  border: 1px solid var(--border);
  border-radius: 6px;
  padding: 3px 10px;
}

/* Chord cards */
.hero-deck {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 8px;
  width: 100%;
}

.hero-card {
  background: var(--surface);
  border: 1px solid var(--border-light);
  border-radius: 10px;
  padding: 14px 10px;
  text-align: center;
  display: flex;
  flex-direction: column;
  gap: 8px;
  position: relative;
  overflow: hidden;
}

.hero-card::before {
  content: '';
  position: absolute;
  top: 0; left: 0; right: 0;
  height: 3px;
  border-radius: 10px 10px 0 0;
}

.hc1::before { background: #d4a84b; }
.hc1 { border-color: rgba(212,168,75,0.3); background: linear-gradient(180deg, rgba(212,168,75,0.08) 0%, var(--surface) 60%); }

.hc2::before { background: #6cabf7; }
.hc2 { border-color: rgba(108,171,247,0.3); background: linear-gradient(180deg, rgba(108,171,247,0.08) 0%, var(--surface) 60%); }

.hc3::before { background: #34d399; }
.hc3 { border-color: rgba(52,211,153,0.3); background: linear-gradient(180deg, rgba(52,211,153,0.08) 0%, var(--surface) 60%); }

.hc4::before { background: #f472b6; }
.hc4 { border-color: rgba(244,114,182,0.3); background: linear-gradient(180deg, rgba(244,114,182,0.08) 0%, var(--surface) 60%); }

.hc-name {
  font-family: 'JetBrains Mono', monospace;
  font-size: 17px;
  font-weight: 800;
  color: var(--text);
  letter-spacing: 0.5px;
}

.hc-notes {
  font-family: 'JetBrains Mono', monospace;
  font-size: 10px;
  font-weight: 500;
  color: var(--text-3);
  letter-spacing: 0.5px;
}

.hc-inv {
  font-size: 10px;
  font-weight: 600;
  text-transform: uppercase;
  letter-spacing: 0.6px;
  padding: 2px 8px;
  border-radius: 999px;
  background: rgba(255,255,255,0.05);
  color: var(--text-3);
  align-self: center;
}

.hero-actions {
  display: flex;
  justify-content: center;
  gap: 16px;
}

/* ---------- Shortcuts pills ---------- */
.shortcuts {
  display: flex;
  gap: 14px;
  flex-wrap: wrap;
}

.shortcut {
  display: inline-flex;
  align-items: center;
  gap: 5px;
  font-size: 12px;
}

.shortcut .key {
  font-family: 'JetBrains Mono', monospace;
  background: rgba(255,255,255,0.06);
  border: 1px solid var(--border);
  border-radius: 4px;
  padding: 1px 6px;
  font-size: 11px;
  font-weight: 600;
  color: var(--gold);
}

.shortcut .label { color: var(--text-3); font-size: 11px; }

/* ---------- Icon buttons ---------- */
.iconRow { display: flex; gap: 6px; }

.iconBtn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  width: 36px;
  height: 36px;
  border-radius: 8px;
  border: 1px solid var(--border);
  background: rgba(255,255,255,0.04);
  color: var(--text-2);
  cursor: pointer;
  text-decoration: none;
  transition: background 0.15s, border-color 0.15s;
}
.iconBtn:hover {
  background: rgba(255,255,255,0.08);
  border-color: var(--border-light);
}
.iconBtn svg { width: 18px; height: 18px; }

/* ==========================================================================
   LAYOUT
   ========================================================================== */
.wrap {
  max-width: 1440px;
  margin: 0 auto;
  padding: 24px;
}

.grid {
  display: grid;
  gap: 24px;
  grid-template-columns: 340px minmax(0, 1fr);
  align-items: start;
}

/* ==========================================================================
   SIDEBAR CONTROLS — clean, minimal, collapsible
   ========================================================================== */
.sidebar {
  display: flex;
  flex-direction: column;
  gap: 2px;
  background: var(--bg-raised);
  border: 1px solid var(--border);
  border-radius: 14px;
  overflow: hidden;
}

.ctrl-section {
  padding: 16px 20px;
  border-bottom: 1px solid var(--border);
}

.ctrl-section:last-child { border-bottom: none; }

.section-title {
  font-size: 11px;
  font-weight: 700;
  letter-spacing: 0.8px;
  text-transform: uppercase;
  color: var(--text-3);
  margin-bottom: 12px;
}

/* --- Collapsible details --- */
.ctrl-details {
  border-bottom: 1px solid var(--border);
}

.ctrl-details:last-of-type { border-bottom: none; }

.ctrl-details summary {
  display: flex;
  align-items: center;
  padding: 14px 20px;
  font-size: 12px;
  font-weight: 600;
  letter-spacing: 0.5px;
  text-transform: uppercase;
  color: var(--text-2);
  cursor: pointer;
  user-select: none;
  list-style: none;
  transition: color 0.15s;
}

.ctrl-details summary::-webkit-details-marker { display: none; }

.ctrl-details summary::before {
  content: '';
  display: inline-block;
  width: 6px;
  height: 6px;
  border-right: 2px solid var(--text-3);
  border-bottom: 2px solid var(--text-3);
  transform: rotate(-45deg);
  margin-right: 12px;
  transition: transform 0.2s;
  flex-shrink: 0;
}

.ctrl-details[open] summary::before {
  transform: rotate(45deg);
}

.ctrl-details summary:hover { color: var(--text); }

.ctrl-body {
  padding: 4px 20px 18px;
}

/* --- Form fields --- */
.field {
  margin-bottom: 14px;
}
.field:last-child { margin-bottom: 0; }

label {
  display: block;
  font-size: 12px;
  font-weight: 500;
  color: var(--text-3);
  margin-bottom: 6px;
}

select,
input[type="number"] {
  width: 100%;
  padding: 9px 12px;
  border-radius: 8px;
  border: 1px solid var(--border);
  background: var(--bg);
  color: var(--text);
  font-family: inherit;
  font-size: 13px;
  outline: none;
  transition: border-color 0.15s;
}

select:focus,
input[type="number"]:focus {
  border-color: var(--gold-dim);
}

.field-row {
  display: flex;
  gap: 12px;
  margin-bottom: 14px;
}
.field-row .field { flex: 1; margin-bottom: 0; }

.range-row {
  display: flex;
  align-items: center;
  gap: 12px;
}

.range-row input[type="range"] { flex: 1; }

.range-value {
  font-family: 'JetBrains Mono', monospace;
  font-size: 12px;
  font-weight: 600;
  color: var(--gold);
  white-space: nowrap;
  min-width: 56px;
  text-align: right;
}

.hint-inline {
  font-weight: 400;
  color: var(--text-3);
  font-size: 11px;
  margin-left: 4px;
}

/* --- Range slider --- */
input[type="range"] {
  width: 100%;
  height: 20px;
  border: none;
  background: transparent;
  outline: none;
  -webkit-appearance: none;
  appearance: none;
}

input[type="range"]::-webkit-slider-track {
  height: 4px;
  background: var(--border);
  border-radius: 2px;
}

input[type="range"]::-webkit-slider-thumb {
  -webkit-appearance: none;
  width: 16px;
  height: 16px;
  border-radius: 50%;
  background: var(--gold);
  border: 2px solid var(--bg);
  margin-top: -6px;
  cursor: pointer;
  box-shadow: 0 0 8px rgba(212,168,75,0.3);
}

input[type="range"]::-moz-range-track {
  height: 4px;
  background: var(--border);
  border-radius: 2px;
  border: none;
}

input[type="range"]::-moz-range-thumb {
  width: 16px;
  height: 16px;
  border-radius: 50%;
  background: var(--gold);
  border: 2px solid var(--bg);
  cursor: pointer;
}

/* --- Toggle switch --- */
.switch {
  display: flex;
  align-items: center;
  gap: 10px;
  cursor: pointer;
  padding: 4px 0;
  user-select: none;
}

.switch input {
  position: absolute;
  opacity: 0;
  width: 0;
  height: 0;
  pointer-events: none;
}

.switch-track {
  width: 36px;
  height: 20px;
  background: var(--border);
  border-radius: 10px;
  position: relative;
  flex-shrink: 0;
  transition: background 0.2s;
}

.switch-track::after {
  content: '';
  position: absolute;
  top: 2px;
  left: 2px;
  width: 16px;
  height: 16px;
  border-radius: 50%;
  background: var(--text-3);
  transition: transform 0.2s, background 0.2s;
}

.switch input:checked + .switch-track {
  background: var(--gold);
}

.switch input:checked + .switch-track::after {
  transform: translateX(16px);
  background: #fff;
}

.switch-text {
  font-size: 13px;
  font-weight: 500;
  color: var(--text);
}

.switch-row {
  display: flex;
  gap: 20px;
  margin-bottom: 14px;
}

/* ==========================================================================
   MAIN PANEL — action bar + exercises
   ========================================================================== */
.main-panel {
  display: flex;
  flex-direction: column;
  gap: 16px;
}

/* --- Action bar (Generate, Play) --- */
.action-bar {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 12px;
  flex-wrap: wrap;
}

.action-bar-right {
  display: flex;
  align-items: center;
  gap: 10px;
}

.ex-label {
  font-size: 12px;
  color: var(--text-3);
  font-weight: 500;
  margin-bottom: 0;
}

.action-bar select {
  width: auto;
  padding: 8px 12px;
}

.btn-generate {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  padding: 10px 20px;
  border-radius: 10px;
  border: 1px solid var(--gold-dim);
  background: var(--gold-glow);
  color: var(--gold);
  font-size: 14px;
  font-weight: 700;
  cursor: pointer;
  transition: background 0.15s, box-shadow 0.15s;
  width: auto;
}

.btn-generate:hover {
  background: var(--gold-strong);
  box-shadow: 0 0 20px rgba(212,168,75,0.1);
}

.btn-generate svg { width: 18px; height: 18px; }

.btn-play {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  padding: 10px 18px;
  border-radius: 10px;
  border: 1px solid var(--border-light);
  background: var(--surface);
  color: var(--text);
  font-size: 14px;
  font-weight: 600;
  cursor: pointer;
  transition: all 0.15s;
  width: auto;
}

.btn-play:hover {
  background: var(--surface-alt);
  border-color: var(--blue);
}

.btn-play.playing {
  border-color: var(--green);
  background: var(--green-glow);
  color: var(--green);
  box-shadow: 0 0 20px rgba(74,222,128,0.08);
}

.btn-play svg { width: 14px; height: 14px; }

/* --- Display area --- */
.display {
  background: var(--bg-raised);
  border: 1px solid var(--border);
  border-radius: 14px;
  padding: 20px;
  position: relative;
  overflow: hidden;
}

/* Hidden panelHeader — we moved buttons to action-bar but keep for JS compat */
.panelHeader { display: none; }

/* --- Exercises --- */
#exercises {
  display: flex;
  flex-direction: column;
  gap: 20px;
}

.exercise {
  border: 1px solid color-mix(in srgb, var(--ex-color, var(--gold)) 25%, var(--border));
  padding: 16px;
  border-radius: 12px;
  background: color-mix(in srgb, var(--ex-color, var(--gold)) 6%, var(--surface));
  overflow: hidden;
  position: relative;
}

.exercise::before {
  content: '';
  position: absolute;
  top: 0; left: 0; right: 0;
  height: 3px;
  background: linear-gradient(90deg, var(--ex-color, var(--gold)), transparent);
  border-radius: 12px 12px 0 0;
  opacity: 0.7;
}

/* Per-exercise accent colors */
.exercise[data-color="0"] { --ex-color: #d4a84b; } /* gold */
.exercise[data-color="1"] { --ex-color: #6cabf7; } /* blue */
.exercise[data-color="2"] { --ex-color: #34d399; } /* green */
.exercise[data-color="3"] { --ex-color: #f472b6; } /* pink */
.exercise[data-color="4"] { --ex-color: #c084fc; } /* purple */

.exercise .title {
  font-size: 11px;
  color: var(--ex-color, var(--gold));
  margin: 0 0 14px;
  letter-spacing: 0.8px;
  text-transform: uppercase;
  font-weight: 700;
  display: flex;
  align-items: center;
  gap: 12px;
  flex-wrap: wrap;
}

.exercise .title .spacer { flex: 1; min-width: 16px; }

.exercise .playEx {
  padding: 6px 14px;
  border-radius: 8px;
  border: 1px solid var(--border-light);
  background: transparent;
  color: var(--text-2);
  cursor: pointer;
  font-size: 12px;
  font-weight: 600;
  transition: all 0.15s;
  min-height: 32px;
  min-width: auto;
}

.exercise .playEx:hover {
  background: rgba(255,255,255,0.04);
  color: var(--text);
}

.exercise .playEx.active {
  border-color: var(--green);
  color: var(--green);
  background: var(--green-glow);
}

.exercise .dlMidi {
  padding: 6px 14px;
  border-radius: 8px;
  border: 1px solid var(--border);
  background: transparent;
  color: var(--text-3);
  cursor: pointer;
  font-size: 12px;
  font-weight: 500;
  margin-left: 6px;
  transition: all 0.15s;
  min-height: 32px;
  min-width: auto;
}

.exercise .dlMidi:hover {
  color: var(--gold);
  border-color: var(--gold-dim);
}

/* --- Chord cards --- */
.cards {
  display: grid;
  gap: 10px;
  grid-template-columns: repeat(auto-fit, minmax(160px, 1fr));
}

.cardItem {
  background: var(--bg-raised);
  border: 1px solid var(--border);
  border-radius: 10px;
  padding: 10px;
  display: flex;
  flex-direction: column;
  gap: 6px;
  transition: border-color 0.2s, box-shadow 0.2s;
}

.nameBadge {
  padding: 10px 8px;
  border-radius: 8px;
  background: var(--bg);
  color: var(--text);
  font-size: 16px;
  font-weight: 700;
  text-align: center;
  letter-spacing: 0.5px;
  border: none;
}

.invRow {
  padding: 6px 10px;
  border-radius: 6px;
  background: var(--bg);
  font-family: 'JetBrains Mono', monospace;
  font-size: 12px;
  color: var(--text-2);
  border: none;
}

.invRow .root {
  color: var(--root);
  font-weight: 800;
}

.invBadge {
  display: inline-block;
  margin-left: auto;
  font-size: 10px;
  padding: 1px 7px;
  border-radius: 999px;
  background: var(--surface);
  color: var(--gold);
  font-weight: 600;
  border: none;
}

/* --- Chord shape visual (white/black key pattern) --- */
.chord-shape-row {
  display: flex;
  justify-content: center;
  padding: 4px 0 2px;
}

.chord-shape {
  display: block;
  opacity: 0.85;
}

/* Active card */
.cardItem.active {
  border-color: var(--blue);
  box-shadow: 0 0 0 2px var(--blue-glow), 0 4px 16px rgba(0,0,0,0.2);
}

.cardItem.active .nameBadge {
  background: var(--blue-glow);
  color: #fff;
}

.cardItem.active .invRow {
  background: var(--blue-glow);
}

@media (min-width: 1400px) { .cards { grid-template-columns: repeat(5, 1fr); } }
@media (min-width: 1100px) and (max-width: 1399px) { .cards { grid-template-columns: repeat(4, 1fr); } }
@media (min-width: 800px) and (max-width: 1099px) { .cards { grid-template-columns: repeat(3, 1fr); } }
@media (min-width: 550px) and (max-width: 799px) { .cards { grid-template-columns: repeat(2, 1fr); } }
@media (max-width: 549px) { .cards { grid-template-columns: 1fr; } }

/* ==========================================================================
   DONATE
   ========================================================================== */
.donate-section {
  margin-top: 40px;
  padding: 32px;
  background: var(--bg-raised);
  border: 1px solid var(--border);
  border-radius: 14px;
}

.donate-header {
  text-align: center;
  margin-bottom: 24px;
}
.donate-header h3 {
  font-size: 18px;
  font-weight: 700;
  margin-bottom: 6px;
}
.donate-header p {
  font-size: 13px;
  color: var(--text-2);
}

.donate-grid {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 20px;
}

.donate-card {
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: 12px;
  padding: 24px;
  text-align: center;
}

.donate-card h4 {
  font-size: 11px;
  color: var(--gold);
  font-weight: 700;
  text-transform: uppercase;
  letter-spacing: 1px;
  margin-bottom: 16px;
}

.paypal-btn {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  background: linear-gradient(180deg, #0077c0, #003d80);
  color: #fff;
  border: none;
  border-radius: 999px;
  padding: 11px 22px;
  font-size: 14px;
  font-weight: 600;
  cursor: pointer;
  transition: transform 0.15s, box-shadow 0.15s;
  width: auto;
}
.paypal-btn:hover {
  transform: translateY(-1px);
  box-shadow: 0 4px 16px rgba(0,112,186,0.3);
}
.paypal-btn svg { width: 20px; height: 20px; }

.tab-btns {
  display: flex;
  gap: 6px;
  margin-bottom: 14px;
  justify-content: center;
}
.tab-btn {
  background: var(--bg);
  border: 1px solid var(--border);
  border-radius: 6px;
  padding: 6px 14px;
  color: var(--text-2);
  cursor: pointer;
  font-size: 12px;
  font-weight: 500;
  transition: all 0.15s;
  width: auto;
  min-height: 32px;
  min-width: auto;
}
.tab-btn.active {
  background: var(--blue-glow);
  border-color: var(--blue);
  color: var(--blue);
}
.tab-content { display: none; }
.tab-content.active { display: block; }

.upi-qr {
  max-width: 140px;
  border-radius: 10px;
  background: #fff;
  padding: 6px;
  margin: 10px auto;
}
.upi-qr img { border-radius: 6px; }

.upi-info {
  background: var(--bg);
  border-radius: 8px;
  padding: 12px;
  margin-top: 10px;
  font-size: 12px;
  color: var(--text-2);
  text-align: left;
}
.upi-info strong { color: var(--gold); }
.upi-info div + div { margin-top: 4px; }

.bank-details {
  text-align: left;
  background: var(--bg);
  border-radius: 8px;
  padding: 12px;
  font-size: 12px;
}
.bank-details .row {
  display: flex;
  justify-content: space-between;
  padding: 4px 0;
  border-bottom: 1px solid var(--border);
  margin-bottom: 0;
  gap: 8px;
}
.bank-details .row:last-child { border-bottom: none; }
.bank-details .label { color: var(--text-3); }
.bank-details .value {
  color: var(--text);
  font-family: 'JetBrains Mono', monospace;
  font-weight: 500;
  font-size: 11px;
}

/* ==========================================================================
   FOOTER
   ========================================================================== */
.attribution {
  margin-top: 32px;
  padding: 24px;
  text-align: center;
  border-top: 1px solid var(--border);
}
.attribution-link {
  display: inline-flex;
  align-items: center;
  gap: 10px;
  margin-bottom: 8px;
  text-decoration: none;
  color: var(--text-2);
  font-size: 14px;
  font-weight: 600;
}
.attribution-logo {
  height: 28px;
  opacity: 0.7;
}
.attribution p {
  font-size: 12px;
  color: var(--text-3);
}
.attribution p a {
  color: var(--gold);
  text-decoration: none;
}
.attribution p a:hover { text-decoration: underline; }

/* ==========================================================================
   MISC
   ========================================================================== */
.pill {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  background: var(--gold-glow);
  border: 1px solid var(--gold-strong);
  color: var(--gold);
  padding: 5px 10px;
  border-radius: 999px;
  font-size: 11px;
  font-weight: 600;
}

/* Legacy compat classes */
.card { background: transparent; border: none; padding: 0; box-shadow: none; }
.card h2 { display: none; }
.subhead { display: none; }
.toggle { display: none; }
.toggle-group { display: none; }
.settings-group { display: none; }
.row { display: flex; gap: 12px; align-items: flex-start; margin-bottom: 12px; }
.row:last-child { margin-bottom: 0; }
.row > div { flex: 1; }
.mini { display: none; }
.kbd {
  font-family: 'JetBrains Mono', monospace;
  display: inline-block;
  padding: 1px 6px;
  border-radius: 4px;
  border: 1px solid var(--border);
  background: var(--bg);
  font-size: 11px;
  color: var(--gold);
}
.shortcuts-hint { display: none; }
.hint { font-size: 11px; color: var(--text-3); margin-top: 3px; }

/* Touch targets */
button, a.iconBtn, .tab-btn { min-height: 36px; }

/* Print */
@media print {
  body { background: #fff; color: #111; }
  .hero, .sidebar, .donate-section, .attribution { display: none; }
  .grid { grid-template-columns: 1fr; }
  .cardItem { break-inside: avoid; }
}

/* ==========================================================================
   RESPONSIVE
   ========================================================================== */

/* Desktop */
@media (min-width: 1025px) {
  .grid { grid-template-columns: 340px 1fr; }
}

/* Tablet — single column grid, hero stays two-col */
@media (max-width: 1024px) {
  .grid { grid-template-columns: 1fr; }

  .hero h1 { font-size: 42px; }
  .hero-center { padding-bottom: 32px; }
  .hero-demo { gap: 24px; }
  .hc-name { font-size: 14px; }
  .hero-card { padding: 10px 8px; }

  .sidebar {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 0;
  }

  .ctrl-section,
  .ctrl-details {
    border-bottom: 1px solid var(--border);
    border-right: 1px solid var(--border);
  }

  .ctrl-section:nth-child(even),
  .ctrl-details:nth-child(even) {
    border-right: none;
  }
}

/* Mobile */
@media (max-width: 767px) {
  .hero-inner { padding: 16px 16px 0; }
  .hero-nav { margin-bottom: 20px; }
  .hero-center { padding-bottom: 24px; }
  .hero h1 { font-size: 34px; letter-spacing: -1.2px; }
  .hero-tagline { font-size: 14px; margin-bottom: 18px; }

  .hero-features { gap: 6px; margin-bottom: 22px; }
  .feat-pill { font-size: 10px; padding: 4px 10px; }

  .hero-demo { grid-template-columns: 1fr; gap: 24px; text-align: center; }
  .hero-steps { align-items: center; }
  .step { text-align: left; max-width: 340px; }
  .hero-preview { max-width: 400px; margin: 0 auto; }

  .hc-name { font-size: 13px; }
  .hero-card { padding: 8px 6px; gap: 4px; }
  .hc-inv { font-size: 9px; padding: 2px 6px; }
  .hc-notes { font-size: 9px; }

  .hero-actions { overflow-x: auto; -webkit-overflow-scrolling: touch; }
  .shortcuts { flex-wrap: nowrap; gap: 10px; justify-content: center; }
  .shortcut { white-space: nowrap; flex-shrink: 0; }

  .wrap { padding: 16px 12px; }

  .sidebar {
    display: flex;
    flex-direction: column;
  }

  .ctrl-section,
  .ctrl-details {
    border-right: none;
  }

  select, input[type="number"] {
    font-size: 16px;
    padding: 11px 14px;
  }

  .field-row {
    flex-direction: column;
    gap: 10px;
  }

  .switch-row {
    flex-direction: column;
    gap: 8px;
  }

  .action-bar {
    flex-direction: column;
    align-items: stretch;
    gap: 10px;
  }

  .action-bar-right {
    justify-content: space-between;
  }

  .btn-generate, .btn-play {
    justify-content: center;
  }

  .display { padding: 14px; }
  .exercise { padding: 12px; }
  .exercise .title .spacer { display: none; }

  .donate-section { padding: 20px; }
  .donate-grid { grid-template-columns: 1fr; }

  .bank-details .row {
    flex-direction: column;
    gap: 2px;
    align-items: flex-start;
  }
}

/* Small mobile */
@media (max-width: 400px) {
  .hero h1 { font-size: 28px; letter-spacing: -0.8px; }
  .hero-inner { padding: 14px 12px 0; }
  .hero-preview { max-width: 300px; }
  .wrap { padding: 12px 8px; }
  .iconBtn { width: 32px; height: 32px; }
  .iconBtn svg { width: 16px; height: 16px; }
}

/* Touch optimization */
@media (hover: none) and (pointer: coarse) {
  button:active, .iconBtn:active, .tab-btn:active {
    transform: scale(0.97);
    opacity: 0.9;
  }
}

/* Mobile text sizing */
@media (max-width: 767px) {
  .invRow { font-size: 13px; }
  .nameBadge { font-size: 15px; }
}