style.css

/* =============================================
   KEYWAVE — Piano + Learn Mode Styles
   ============================================= */

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

:root {
  --bg: #080c14;
  --surface: #0d1521;
  --surface2: #111d2e;
  --border: #1a2540;
  --border2: #243352;
  --accent: #00e5ff;
  --accent2: #ff3cac;
  --accent3: #ffd600;
  --accent-green: #00ff88;
  --accent-red: #ff4444;
  --white-key: #e8edf5;
  --white-key-active: #c8f5ff;
  --black-key: #111827;
  --black-key-active: #003d55;
  --text: #ccd6f6;
  --text-dim: #4a6080;
  --font-display: 'Bebas Neue', sans-serif;
  --font-mono: 'DM Mono', monospace;
}

html, body { height: 100%; background: var(--bg); color: var(--text); font-family: var(--font-mono); overflow-x: hidden; }

/* ── Background ── */
.bg-grid {
  position: fixed; inset: 0;
  background-image: linear-gradient(rgba(0,229,255,0.04) 1px, transparent 1px), linear-gradient(90deg,rgba(0,229,255,0.04) 1px,transparent 1px);
  background-size: 48px 48px; pointer-events: none; z-index: 0;
}
.glow-orb { position: fixed; border-radius: 50%; filter: blur(90px); pointer-events: none; z-index: 0; }
.orb1 { width:500px;height:500px;background:rgba(0,229,255,0.07);top:-150px;left:-100px; }
.orb2 { width:400px;height:400px;background:rgba(255,60,172,0.06);bottom:-100px;right:-100px; }

/* ── Header ── */
header {
  position: relative; z-index: 20;
  display: flex; align-items: center; justify-content: space-between;
  padding: 22px 48px 0;
}
.logo { font-family: var(--font-display); font-size: 2.6rem; letter-spacing: 0.12em; }
.logo span { color: var(--accent); text-shadow: 0 0 20px rgba(0,229,255,0.5); }
.header-right { display: flex; align-items: center; gap: 20px; }
.meta { display: flex; gap: 20px; font-size: 0.7rem; letter-spacing: 0.16em; color: var(--text-dim); }
.meta span { color: var(--accent); }

/* Learn Mode Toggle Button */
.learn-toggle-btn {
  background: rgba(0,229,255,0.08);
  border: 1px solid var(--accent);
  color: var(--accent);
  font-family: var(--font-mono);
  font-size: 0.7rem;
  letter-spacing: 0.15em;
  padding: 8px 18px;
  border-radius: 8px;
  cursor: pointer;
  transition: all 0.2s;
}
.learn-toggle-btn:hover, .learn-toggle-btn.active {
  background: rgba(0,229,255,0.18);
  box-shadow: 0 0 18px rgba(0,229,255,0.25);
}
.learn-toggle-btn.active {
  color: #fff;
  border-color: var(--accent);
  background: rgba(0,229,255,0.22);
}

/* ══ LEARN MODE PANEL ══ */
.learn-panel {
  position: relative; z-index: 15;
  background: linear-gradient(180deg, #0a1525 0%, #0d1a2c 100%);
  border-bottom: 1px solid var(--border2);
  border-top: 1px solid var(--border2);
  margin: 12px 24px 0;
  border-radius: 16px;
  overflow: hidden;
  animation: slideDown 0.3s ease-out;
  box-shadow: 0 12px 48px rgba(0,0,0,0.5), inset 0 1px 0 rgba(255,255,255,0.04);
}
.learn-panel.hidden { display: none; }
@keyframes slideDown {
  from { opacity:0; transform: translateY(-12px); }
  to   { opacity:1; transform: translateY(0); }
}
/* top accent line */
.learn-panel::before {
  content:''; position:absolute; top:0;left:0;right:0; height:2px;
  background: linear-gradient(90deg, transparent, var(--accent2), var(--accent), var(--accent3), transparent);
}

/* ── Tabs ── */
.learn-tabs {
  display: flex; gap: 4px; padding: 16px 20px 0;
}
.learn-tab {
  background: transparent;
  border: 1px solid var(--border);
  color: var(--text-dim);
  font-family: var(--font-mono);
  font-size: 0.68rem;
  letter-spacing: 0.14em;
  padding: 8px 20px;
  border-radius: 8px 8px 0 0;
  cursor: pointer;
  transition: all 0.15s;
  border-bottom: none;
}
.learn-tab:hover { color: var(--text); background: rgba(255,255,255,0.04); }
.learn-tab.active { background: var(--surface2); color: var(--accent); border-color: var(--border2); }

/* ── Sections ── */
.learn-section { padding: 20px 24px 22px; }
.learn-section.hidden { display: none; }

/* ── SONG MODE ── */
.song-select-row {
  display: flex; align-items: center; gap: 10px; flex-wrap: wrap; margin-bottom: 16px;
}
.song-select-row select {
  background: var(--surface2); border: 1px solid var(--border2);
  color: var(--text); font-family: var(--font-mono); font-size: 0.72rem;
  padding: 7px 12px; border-radius: 7px; cursor: pointer; outline: none;
}
.song-select-row button, .quiz-controls button {
  font-family: var(--font-mono); font-size: 0.68rem; letter-spacing: 0.12em;
  padding: 7px 16px; border-radius: 7px; border: 1px solid var(--border2);
  background: rgba(0,229,255,0.08); color: var(--accent); cursor: pointer; transition: all 0.15s;
}
.song-select-row button:hover, .quiz-controls button:hover { background: rgba(0,229,255,0.18); }
button.danger { background: rgba(255,68,68,0.1) !important; color: var(--accent-red) !important; border-color: rgba(255,68,68,0.3) !important; }
button.danger:hover { background: rgba(255,68,68,0.2) !important; }
button.secondary { background: rgba(255,255,255,0.05) !important; color: var(--text-dim) !important; }
button.secondary:enabled:hover { background: rgba(255,255,255,0.1) !important; color: var(--text) !important; }
button:disabled { opacity: 0.4; cursor: not-allowed; }

/* Note scroll / queue */
.note-scroll-area {
  background: rgba(0,0,0,0.3); border: 1px solid var(--border);
  border-radius: 10px; padding: 12px 16px; margin-bottom: 14px;
  overflow-x: auto; overflow-y: hidden;
}
.note-queue {
  display: flex; gap: 8px; min-height: 44px; align-items: center;
  transition: transform 0.2s ease;
}
.nq-chip {
  flex-shrink: 0; display: flex; flex-direction: column; align-items: center;
  background: var(--surface2); border: 1px solid var(--border2);
  border-radius: 8px; padding: 5px 10px; min-width: 44px;
  font-size: 0.62rem; color: var(--text-dim); transition: all 0.15s;
}
.nq-chip .nq-note { font-family: var(--font-display); font-size: 1.1rem; color: var(--text); line-height:1; }
.nq-chip .nq-key  { font-size: 0.58rem; color: var(--accent); margin-top: 2px; }
.nq-chip.current  {
  background: rgba(0,229,255,0.15); border-color: var(--accent);
  transform: scale(1.15); box-shadow: 0 0 18px rgba(0,229,255,0.3);
}
.nq-chip.current .nq-note { color: var(--accent); }
.nq-chip.done { opacity: 0.3; }
.nq-chip.upcoming { opacity: 0.7; }

/* Press hint */
.press-hint {
  display: flex; gap: 20px; align-items: center;
  background: rgba(0,0,0,0.25); border: 1px solid var(--border);
  border-radius: 12px; padding: 14px 24px; margin-bottom: 12px; flex-wrap: wrap;
}
.press-block { display: flex; flex-direction: column; align-items: center; gap: 3px; }
.press-hint-label { font-size: 0.55rem; letter-spacing: 0.2em; color: var(--text-dim); }
.hint-note { font-family: var(--font-display); font-size: 2.4rem; color: var(--accent); letter-spacing: 0.08em; line-height:1; text-shadow: 0 0 20px rgba(0,229,255,0.5); }
.hint-key  { font-family: var(--font-display); font-size: 2rem; color: var(--accent2); text-shadow: 0 0 16px rgba(255,60,172,0.5); line-height:1; }
.hint-finger { font-family: var(--font-mono); font-size: 0.85rem; color: var(--accent3); }

/* Progress */
.song-progress-row {
  display: flex; align-items: center; gap: 12px; font-size: 0.65rem; color: var(--text-dim);
}
.progress-bar { flex: 1; height: 5px; background: var(--border); border-radius: 3px; overflow: hidden; }
.progress-fill { height: 100%; background: linear-gradient(90deg, var(--accent), var(--accent2)); border-radius: 3px; width: 0%; transition: width 0.3s ease; }

/* ── FREE LEARN MODE ── */
.free-info { display: flex; gap: 14px; flex-wrap: wrap; margin-bottom: 20px; }
.free-card {
  flex: 1; min-width: 100px; background: rgba(0,0,0,0.25);
  border: 1px solid var(--border2); border-radius: 12px; padding: 14px 18px;
  display: flex; flex-direction: column; align-items: center; gap: 6px;
}
.free-card-label { font-size: 0.55rem; letter-spacing: 0.2em; color: var(--text-dim); }
.free-big { font-family: var(--font-display); font-size: 2rem; color: var(--accent); letter-spacing: 0.06em; }
.free-big.accent2 { color: var(--accent2); text-shadow: 0 0 12px rgba(255,60,172,0.4); }
.free-big.accent3 { color: var(--accent3); font-size: 1.5rem; }

.note-reference { background: rgba(0,0,0,0.2); border: 1px solid var(--border); border-radius: 10px; padding: 14px 18px; }
.ref-title { font-size: 0.58rem; letter-spacing: 0.2em; color: var(--text-dim); margin-bottom: 10px; }
.ref-grid { display: flex; flex-wrap: wrap; gap: 6px; }
.ref-item {
  display: flex; flex-direction: column; align-items: center; gap: 2px;
  background: var(--surface2); border: 1px solid var(--border);
  border-radius: 8px; padding: 6px 10px; min-width: 52px;
}
.ref-item.black-ref { border-color: rgba(255,60,172,0.25); }
.ref-note { font-family: var(--font-display); font-size: 1rem; color: var(--text); }
.ref-key  { font-size: 0.7rem; color: var(--accent); font-weight: 500; }
.ref-fgr  { font-size: 0.52rem; color: var(--text-dim); }

/* ── QUIZ MODE ── */
.quiz-top { display: flex; gap: 14px; margin-bottom: 16px; flex-wrap: wrap; }
.quiz-score-block {
  flex: 1; min-width: 80px; background: rgba(0,0,0,0.3);
  border: 1px solid var(--border2); border-radius: 12px;
  padding: 12px; display: flex; flex-direction: column; align-items: center; gap: 4px;
}
.qs-label { font-size: 0.55rem; letter-spacing: 0.18em; color: var(--text-dim); }
.qs-val { font-family: var(--font-display); font-size: 2rem; color: var(--text); line-height: 1; }
.qs-val.accent2 { color: var(--accent2); }
.qs-val.accent3 { color: var(--accent3); }

.quiz-challenge {
  background: rgba(0,0,0,0.25); border: 1px solid var(--border);
  border-radius: 12px; padding: 18px 24px; text-align: center; margin-bottom: 14px;
}
.quiz-prompt { font-family: var(--font-display); font-size: 2rem; color: var(--accent); letter-spacing: 0.08em; margin-bottom: 6px; }
.quiz-sub { font-size: 0.65rem; color: var(--text-dim); letter-spacing: 0.1em; }
.quiz-feedback {
  margin-top: 10px; font-family: var(--font-display); font-size: 1.5rem;
  letter-spacing: 0.1em; min-height: 32px; transition: all 0.2s;
}
.quiz-feedback.correct { color: var(--accent-green); }
.quiz-feedback.wrong   { color: var(--accent-red); }

.quiz-controls { display: flex; align-items: center; gap: 12px; flex-wrap: wrap; }
.difficulty-row { display: flex; align-items: center; gap: 8px; margin-left: auto; }
.difficulty-row label { font-size: 0.6rem; letter-spacing: 0.15em; color: var(--text-dim); }
.diff-btn {
  font-family: var(--font-mono); font-size: 0.62rem; letter-spacing: 0.1em;
  padding: 5px 12px; border-radius: 6px; border: 1px solid var(--border2);
  background: rgba(255,255,255,0.04); color: var(--text-dim); cursor: pointer; transition: all 0.15s;
}
.diff-btn:hover { color: var(--text); }
.diff-btn.active { background: rgba(0,229,255,0.12); color: var(--accent); border-color: var(--accent); }

/* ══ MAIN PIANO ══ */
main {
  position: relative; z-index: 10;
  display: flex; flex-direction: column; align-items: center;
  padding: 24px 24px 0; gap: 20px;
}

.piano-wrapper {
  background: linear-gradient(180deg, #0d1a2e 0%, #060a10 100%);
  border: 1px solid var(--border); border-radius: 20px;
  padding: 28px 32px 0;
  box-shadow: 0 24px 80px rgba(0,0,0,0.7), inset 0 1px 0 rgba(255,255,255,0.04);
  position: relative; overflow: hidden;
}
.piano-wrapper::before {
  content:''; position:absolute; top:0;left:0;right:0; height:3px;
  background: linear-gradient(90deg, transparent, var(--accent), var(--accent2), transparent);
}

/* ── Piano ── */
.piano { display:flex; position:relative; height:200px; gap:3px; user-select:none; }

/* White keys */
.key {
  position: relative; display:flex; flex-direction:column; align-items:center;
  justify-content:flex-end; padding-bottom:12px;
  width:52px; height:200px;
  background: linear-gradient(180deg,#d0d8e8 0%,#e8edf5 40%,#c5ccdb 100%);
  border-radius: 0 0 10px 10px; border: 1px solid #b0bcd0; border-top:none;
  box-shadow: 0 8px 24px rgba(0,0,0,0.6), inset 0 1px 0 rgba(255,255,255,0.9);
  cursor: pointer; transition: background 0.06s, transform 0.06s, box-shadow 0.06s; z-index:1;
}
.key:hover { background: linear-gradient(180deg,#e0eaf8 0%,#fff 40%,#d5ddef 100%); }
.key.active, .key:active {
  background: linear-gradient(180deg,#c8f5ff 0%,#a8edfa 100%);
  transform: scaleY(0.97) translateY(3px);
  box-shadow: 0 2px 8px rgba(0,0,0,0.5), inset 0 2px 6px rgba(0,229,255,0.25);
}

/* Glow highlight for learn mode */
.key.learn-highlight {
  background: linear-gradient(180deg, #fffbe0 0%, #ffd600 40%, #e6c000 100%) !important;
  box-shadow: 0 0 24px rgba(255,214,0,0.7), 0 8px 24px rgba(0,0,0,0.5) !important;
  transform: scaleY(0.99);
  animation: pulse-key 0.6s ease-in-out infinite alternate;
}
.key.black.learn-highlight {
  background: linear-gradient(180deg, #664d00 0%, #ffb300 100%) !important;
  box-shadow: 0 0 20px rgba(255,179,0,0.8) !important;
}
@keyframes pulse-key {
  from { box-shadow: 0 0 18px rgba(255,214,0,0.6), 0 8px 24px rgba(0,0,0,0.5); }
  to   { box-shadow: 0 0 36px rgba(255,214,0,1),   0 8px 24px rgba(0,0,0,0.5); }
}

/* Quiz correct / wrong flash */
.key.quiz-correct { background: linear-gradient(180deg, #00ff88 0%, #00cc66 100%) !important; box-shadow: 0 0 24px rgba(0,255,136,0.7) !important; }
.key.quiz-wrong   { background: linear-gradient(180deg, #ff4444 0%, #cc0000 100%) !important; box-shadow: 0 0 24px rgba(255,68,68,0.7) !important; }

.key .label { font-family: var(--font-mono); font-size: 0.58rem; font-weight:500; letter-spacing:0.08em; color:#7a8aaa; }
.key .kbd   { font-size: 0.65rem; font-weight:500; color: var(--accent); letter-spacing:0.06em; margin-top:2px; opacity:0.8; }
.key.active .label, .key.active .kbd { color: #00b8d4; }

/* Black keys */
.key.black {
  position:absolute; top:0; width:34px; height:125px;
  background: linear-gradient(180deg,#1e2a3e 0%,#111827 60%,#0a0f1a 100%);
  border-radius: 0 0 8px 8px; border: 1px solid #0a0f1a; border-top:none;
  box-shadow: 0 10px 20px rgba(0,0,0,0.8), inset 0 1px 0 rgba(255,255,255,0.08);
  z-index:3; padding-bottom:8px;
}
.key.black:hover { background: linear-gradient(180deg,#2a3d5e 0%,#1e2d45 60%,#111827 100%); }
.key.black.active, .key.black:active {
  background: linear-gradient(180deg,#004d69 0%,#003d55 100%);
  transform: scaleY(0.96) translateY(3px);
  box-shadow: 0 3px 8px rgba(0,0,0,0.9), inset 0 2px 6px rgba(0,229,255,0.3);
}
.key.black .label { color: #3a5070; font-size:0.52rem; }
.key.black .kbd   { color: var(--accent2); font-size:0.6rem; }

.key::after {
  content:''; position:absolute; inset:0; border-radius:inherit;
  background: radial-gradient(circle at center, rgba(0,229,255,0.3) 0%, transparent 70%);
  opacity:0; pointer-events:none; transition: opacity 0.12s;
}
.key.active::after { opacity:1; }

/* ── Legend ── */
.legend { display:flex; flex-direction:column; gap:4px; align-items:center; width:100%; max-width:900px; }
.legend-row { display:flex; gap:6px; justify-content:center; flex-wrap:wrap; }
.legend-chip {
  font-family: var(--font-mono); font-size:0.6rem; letter-spacing:0.1em;
  color: var(--text-dim); background: rgba(255,255,255,0.03);
  border: 1px solid var(--border); border-radius:4px;
  padding: 2px 7px; min-width:34px; text-align:center;
}
.black-labels .legend-chip { color: var(--accent2); border-color: rgba(255,60,172,0.2); }

/* ── Controls ── */
.controls { display:flex; gap:28px; align-items:flex-end; flex-wrap:wrap; justify-content:center; padding: 0 16px; }
.control-group { display:flex; flex-direction:column; gap:8px; }
.control-group label { font-size:0.6rem; letter-spacing:0.2em; color:var(--text-dim); }
.btn-group { display:flex; align-items:center; gap:6px; }
.btn-group button {
  background: rgba(255,255,255,0.05); border: 1px solid var(--border);
  color: var(--accent); font-family: var(--font-mono); font-size:1rem;
  width:34px; height:34px; border-radius:6px; cursor:pointer; transition: all 0.15s;
}
.btn-group button:hover { background: rgba(0,229,255,0.1); border-color: var(--accent); }
.btn-group span { font-family: var(--font-display); font-size:1.4rem; color:var(--text); min-width:24px; text-align:center; }
.wave-group { gap:4px; }
.wave-btn {
  background: rgba(255,255,255,0.04) !important; border: 1px solid var(--border) !important;
  color: var(--text-dim) !important; font-family: var(--font-mono) !important;
  font-size:0.62rem !important; letter-spacing:0.1em;
  padding: 6px 10px; border-radius:6px; cursor:pointer; transition: all 0.15s;
  width:auto !important; height:auto !important;
}
.wave-btn:hover { background: rgba(0,229,255,0.08) !important; color: var(--accent) !important; }
.wave-btn.active { background: rgba(0,229,255,0.15) !important; border-color: var(--accent) !important; color: var(--accent) !important; }
input[type="range"] {
  -webkit-appearance:none; width:140px; height:4px;
  background: var(--border); border-radius:2px; outline:none; cursor:pointer;
}
input[type="range"]::-webkit-slider-thumb {
  -webkit-appearance:none; width:16px; height:16px;
  background: var(--accent); border-radius:50%; box-shadow:0 0 10px rgba(0,229,255,0.5); transition:transform 0.1s;
}
input[type="range"]::-webkit-slider-thumb:hover { transform: scale(1.2); }

/* ── Note Display ── */
.note-display {
  position:fixed; top:28px; left:50%; transform:translateX(-50%);
  font-family: var(--font-display); font-size:3.5rem; letter-spacing:0.15em;
  color: var(--accent); text-shadow: 0 0 30px rgba(0,229,255,0.6);
  pointer-events:none; z-index:200; opacity:0; transition: opacity 0.1s;
}
.note-display.show { opacity:1; animation: noteFlash 0.5s ease-out forwards; }
@keyframes noteFlash {
  0%   { opacity:1; transform:translateX(-50%) scale(1.1); }
  40%  { opacity:1; transform:translateX(-50%) scale(1); }
  100% { opacity:0; transform:translateX(-50%) scale(0.9); }
}

/* ── Footer ── */
footer {
  position:relative; z-index:10;
  display:flex; justify-content:center; gap:40px;
  padding:22px 48px; font-size:0.58rem; letter-spacing:0.2em; color:var(--text-dim); margin-top:auto;
}
#mode-indicator { color: var(--accent2); }

/* ── Responsive ── */
@media(max-width:900px){
  header{padding:16px 20px 0;}
  .piano{height:160px;gap:2px;}
  .key{width:38px;height:160px;}
  .key.black{width:26px;height:98px;}
  .piano-wrapper{padding:18px 16px 0;}
  .controls{gap:16px;}
  input[type="range"]{width:100px;}
  .learn-panel{margin:10px 12px 0;}
}
@media(max-width:600px){
  .logo{font-size:2rem;}
  .piano{height:130px;}
  .key{width:30px;height:130px;}
  .key.black{width:20px;height:80px;}
  .piano-wrapper{padding:12px 8px 0;}
  footer{flex-direction:column;align-items:center;gap:6px;}
  .header-right{flex-direction:column;gap:8px;align-items:flex-end;}
  .free-info{gap:8px;}
  .quiz-top{gap:8px;}
}