/* ═══════════════════════════════════════════════════════════════
   TonaMisa — Style Sheet
   Design: Dark glassmorphism, purple-violet accent palette
   ═══════════════════════════════════════════════════════════════ */

/* ── Reset & tokens ──────────────────────────────────────────── */
*, *::before, *::after {
  box-sizing: border-box;
  margin: 0;
  padding: 0;
}

:root {
  /* Colors */
  --clr-bg:           #0b0c14;
  --clr-surface:      #11131f;
  --clr-surface-2:    #181a2e;
  --clr-border:       rgba(255,255,255,0.07);
  --clr-border-glow:  rgba(139,92,246,0.35);

  --clr-accent:       #8b5cf6;
  --clr-accent-soft:  rgba(139,92,246,0.18);
  --clr-accent-2:     #a78bfa;
  --clr-accent-3:     #c4b5fd;

  --clr-highlight:    #7c3aed;
  --clr-highlight-2:  #6d28d9;

  --clr-green:        #34d399;
  --clr-green-soft:   rgba(52,211,153,0.15);
  --clr-red:          #f87171;
  --clr-amber:        #fbbf24;

  --clr-text-1:       #f0f0fa;
  --clr-text-2:       #9b9bbd;
  --clr-text-3:       #5c5c82;

  /* Typography */
  --font-sans:        'Inter', system-ui, sans-serif;
  --font-mono:        'JetBrains Mono', monospace;

  /* Spacing */
  --space-xs: 0.25rem;
  --space-sm: 0.5rem;
  --space-md: 1rem;
  --space-lg: 1.5rem;
  --space-xl: 2rem;
  --space-2xl: 3rem;

  /* Radii */
  --radius-sm:   8px;
  --radius-md:   16px;
  --radius-lg:   24px;
  --radius-full: 9999px;

  /* Shadows */
  --shadow-card: 0 4px 32px rgba(0,0,0,0.5);
  --shadow-glow: 0 0 40px rgba(139,92,246,0.25);
  --shadow-key-active: 0 0 20px rgba(139,92,246,0.7), 0 0 40px rgba(139,92,246,0.4);

  /* Transitions */
  --t-fast:   120ms ease;
  --t-normal: 220ms ease;
  --t-slow:   400ms ease;
}

/* ── Base ────────────────────────────────────────────────────── */
html {
  font-size: 16px;
  scroll-behavior: smooth;
}

body {
  font-family: var(--font-sans);
  background-color: var(--clr-bg);
  color: var(--clr-text-1);
  min-height: 100dvh;
  overflow-x: hidden;
  -webkit-font-smoothing: antialiased;
}

/* ── Background blobs ────────────────────────────────────────── */
.bg-blob {
  position: fixed;
  border-radius: 50%;
  filter: blur(80px);
  pointer-events: none;
  z-index: 0;
  animation: blobDrift 14s ease-in-out infinite alternate;
}

.bg-blob-1 {
  width: 500px; height: 500px;
  background: radial-gradient(circle, rgba(109,40,217,0.25), transparent 70%);
  top: -120px; left: -100px;
  animation-duration: 16s;
}

.bg-blob-2 {
  width: 420px; height: 420px;
  background: radial-gradient(circle, rgba(139,92,246,0.15), transparent 70%);
  bottom: -80px; right: -60px;
  animation-duration: 20s;
  animation-delay: -6s;
}

.bg-blob-3 {
  width: 300px; height: 300px;
  background: radial-gradient(circle, rgba(167,139,250,0.1), transparent 70%);
  top: 40%; left: 50%;
  transform: translate(-50%, -50%);
  animation-duration: 12s;
  animation-delay: -3s;
}

@keyframes blobDrift {
  from { transform: translate(0, 0) scale(1); }
  to   { transform: translate(30px, 20px) scale(1.05); }
}

/* ── App Shell ───────────────────────────────────────────────── */
.app-shell {
  position: relative;
  z-index: 1;
  display: flex;
  flex-direction: column;
  min-height: 100dvh;
  max-width: 680px;
  margin: 0 auto;
  padding: 0 var(--space-md);
}

/* ── Header ──────────────────────────────────────────────────── */
.app-header {
  padding: var(--space-xl) 0 var(--space-lg);
  text-align: center;
}

.logo {
  display: flex;
  align-items: center;
  justify-content: center;
  gap: var(--space-sm);
  margin-bottom: var(--space-xs);
}

.logo-icon {
  width: 2.4rem;
  height: 2.4rem;
  border-radius: 10px;
  object-fit: cover;
  box-shadow: 0 0 12px rgba(139,92,246,0.5);
  animation: iconFloat 3s ease-in-out infinite;
  flex-shrink: 0;
}

@keyframes iconFloat {
  0%, 100% { transform: translateY(0); }
  50%       { transform: translateY(-4px); }
}

.logo-text {
  font-size: 2rem;
  font-weight: 800;
  letter-spacing: -0.03em;
  background: linear-gradient(135deg, var(--clr-accent-3) 0%, var(--clr-accent) 60%, var(--clr-highlight-2) 100%);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
}

.logo-tagline {
  font-size: 0.8rem;
  color: var(--clr-text-3);
  font-weight: 400;
  letter-spacing: 0.02em;
}

/* ── Main ────────────────────────────────────────────────────── */
.app-main {
  flex: 1;
  display: flex;
  flex-direction: column;
  gap: var(--space-lg);
  padding-bottom: var(--space-xl);
}

/* ── Status bar ──────────────────────────────────────────────── */
.status-bar {
  display: flex;
  align-items: center;
  justify-content: center;
  gap: var(--space-sm);
  padding: var(--space-sm) var(--space-lg);
  background: var(--clr-surface);
  border: 1px solid var(--clr-border);
  border-radius: var(--radius-full);
  width: fit-content;
  margin: 0 auto;
  font-size: 0.82rem;
  font-weight: 500;
  color: var(--clr-text-2);
  letter-spacing: 0.04em;
  transition: border-color var(--t-normal), background var(--t-normal);
}

.status-bar.active {
  border-color: var(--clr-green);
  background: var(--clr-green-soft);
  color: var(--clr-green);
}

.status-bar.waiting {
  border-color: var(--clr-amber);
  background: rgba(251,191,36,0.08);
  color: var(--clr-amber);
}

.status-dot {
  width: 8px;
  height: 8px;
  border-radius: 50%;
  background: var(--clr-text-3);
  transition: background var(--t-normal);
}

.status-bar.active .status-dot {
  background: var(--clr-green);
  box-shadow: 0 0 8px var(--clr-green);
  animation: pulse 1.4s ease-in-out infinite;
}

.status-bar.waiting .status-dot {
  background: var(--clr-amber);
  box-shadow: 0 0 8px var(--clr-amber);
  animation: pulse 0.8s ease-in-out infinite;
}

@keyframes pulse {
  0%, 100% { opacity: 1; }
  50%       { opacity: 0.35; }
}

/* ── Section eyebrow ─────────────────────────────────────────── */
.section-eyebrow {
  font-size: 0.68rem;
  font-weight: 700;
  letter-spacing: 0.15em;
  color: var(--clr-text-3);
  text-align: center;
  margin-bottom: var(--space-md);
  text-transform: uppercase;
}

/* ── Note Display Card ───────────────────────────────────────── */
.note-display-card {
  background: linear-gradient(145deg, var(--clr-surface-2), var(--clr-surface));
  border: 1px solid var(--clr-border);
  border-radius: var(--radius-lg);
  padding: var(--space-xl) var(--space-xl) var(--space-lg);
  box-shadow: var(--shadow-card);
  position: relative;
  overflow: hidden;
  transition: border-color var(--t-normal), box-shadow var(--t-slow);
}

.note-display-card.has-note {
  border-color: var(--clr-border-glow);
  box-shadow: var(--shadow-card), var(--shadow-glow);
}

/* Subtle inner shine */
.note-display-card::before {
  content: '';
  position: absolute;
  inset: 0;
  background: radial-gradient(ellipse at 50% 0%, rgba(139,92,246,0.08) 0%, transparent 60%);
  pointer-events: none;
}

.note-main {
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: var(--space-xs);
  min-height: 9rem;
  justify-content: center;
}

.note-name {
  font-size: clamp(5rem, 20vw, 8rem);
  font-weight: 900;
  line-height: 1;
  letter-spacing: -0.04em;
  font-family: var(--font-sans);
  color: var(--clr-text-1);
  transition: color var(--t-fast), transform var(--t-fast);
  will-change: transform;
}

.note-name.active {
  background: linear-gradient(135deg, #fff 20%, var(--clr-accent-3) 60%, var(--clr-accent) 100%);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
  transform: scale(1.03);
}

.note-name.idle {
  color: var(--clr-text-3);
}

.note-detail {
  font-size: 0.9rem;
  font-weight: 500;
  color: var(--clr-text-2);
  letter-spacing: 0.05em;
  font-family: var(--font-mono);
  transition: color var(--t-normal);
  min-height: 1.4em;
}

.note-detail.active {
  color: var(--clr-accent-2);
}

/* Frequency display */
.frequency-display {
  display: flex;
  justify-content: center;
  margin-top: var(--space-sm);
}

.freq-value {
  font-family: var(--font-mono);
  font-size: 0.8rem;
  color: var(--clr-text-3);
  background: rgba(255,255,255,0.04);
  border: 1px solid var(--clr-border);
  border-radius: var(--radius-full);
  padding: 3px 14px;
  letter-spacing: 0.05em;
  transition: color var(--t-normal), border-color var(--t-normal);
  min-width: 96px;
  text-align: center;
}

.freq-value.active {
  color: var(--clr-accent-3);
  border-color: rgba(139,92,246,0.3);
}

/* Waveform canvas */
.waveform-canvas {
  display: block;
  width: 100%;
  height: 52px;
  margin-top: var(--space-md);
  border-radius: var(--radius-sm);
  opacity: 0.6;
  background: transparent;
}

/* ── Keyboard ────────────────────────────────────────────────── */
.keyboard-section {
  background: linear-gradient(145deg, var(--clr-surface-2), var(--clr-surface));
  border: 1px solid var(--clr-border);
  border-radius: var(--radius-lg);
  padding: var(--space-xl) var(--space-md) var(--space-lg);
  box-shadow: var(--shadow-card);
}

.keyboard-wrapper {
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: var(--space-sm);
  overflow-x: auto;
  padding-bottom: var(--space-xs);
  scrollbar-width: thin;
  scrollbar-color: var(--clr-accent) transparent;
}

.keyboard-wrapper::-webkit-scrollbar        { height: 4px; }
.keyboard-wrapper::-webkit-scrollbar-track  { background: transparent; }
.keyboard-wrapper::-webkit-scrollbar-thumb  { background: var(--clr-accent); border-radius: 2px; }

.keyboard {
  display: flex;
  align-items: flex-start;
  justify-content: flex-start;
  position: relative;
  height: 140px;
  width: fit-content;
  margin: 0 auto;
  user-select: none;
}

/* White keys */
.key {
  position: relative;
  border-radius: 0 0 var(--radius-sm) var(--radius-sm);
  cursor: default;
  transition: background var(--t-fast), box-shadow var(--t-fast), transform var(--t-fast);
}

.key.white {
  background: linear-gradient(180deg, #e8e8f0 0%, #f5f5ff 40%, #ffffff 100%);
  border: 1px solid rgba(0,0,0,0.3);
  border-top: none;
  width: 42px;
  height: 140px;
  margin: 0 1.5px;
  z-index: 1;
  box-shadow: 0 4px 8px rgba(0,0,0,0.4), inset 0 1px 0 rgba(255,255,255,0.6);
}

.key.white:hover {
  background: linear-gradient(180deg, #d0d0e8 0%, #eaeaf8 40%, #f8f8ff 100%);
}

.key.black {
  background: linear-gradient(180deg, #1a1a2e 0%, #252540 50%, #1e1e35 100%);
  border: 1px solid rgba(0,0,0,0.5);
  border-top: none;
  width: 28px;
  height: 88px;
  position: absolute;
  z-index: 2;
  border-radius: 0 0 5px 5px;
  box-shadow: 0 4px 10px rgba(0,0,0,0.7), inset 0 -2px 4px rgba(255,255,255,0.05);
}

/* Active / highlighted key */
.key.white.highlighted {
  background: linear-gradient(180deg, var(--clr-highlight) 0%, var(--clr-accent) 40%, var(--clr-accent-2) 100%);
  box-shadow: var(--shadow-key-active), 0 4px 8px rgba(0,0,0,0.4);
  transform: scaleY(0.98) translateY(1px);
}

.key.black.highlighted {
  background: linear-gradient(180deg, var(--clr-highlight-2) 0%, var(--clr-accent) 60%, var(--clr-accent-2) 100%);
  box-shadow: var(--shadow-key-active), 0 4px 10px rgba(0,0,0,0.7);
}

/* Key label */
.key-label {
  position: absolute;
  bottom: 6px;
  left: 50%;
  transform: translateX(-50%);
  font-size: 0.6rem;
  font-weight: 600;
  font-family: var(--font-mono);
  color: rgba(30,30,60,0.6);
  letter-spacing: 0;
  pointer-events: none;
  white-space: nowrap;
  transition: color var(--t-fast);
}

.key.black .key-label {
  color: rgba(200,200,255,0.3);
  font-size: 0.52rem;
  bottom: 4px;
}

.key.highlighted .key-label {
  color: rgba(255,255,255,0.9);
}

.key.black.highlighted .key-label {
  color: rgba(255,255,255,0.95);
}

/* Octave hint */
.keyboard-octave-hint {
  font-size: 0.72rem;
  font-family: var(--font-mono);
  color: var(--clr-text-3);
  letter-spacing: 0.08em;
  min-height: 1.2em;
  text-align: center;
}

/* ── Controls ────────────────────────────────────────────────── */
.controls {
  display: flex;
  justify-content: center;
}

.btn-primary {
  display: flex;
  align-items: center;
  gap: var(--space-sm);
  padding: 0.875rem 2.25rem;
  font-family: var(--font-sans);
  font-size: 1rem;
  font-weight: 700;
  color: #fff;
  background: linear-gradient(135deg, var(--clr-highlight) 0%, var(--clr-accent) 100%);
  border: none;
  border-radius: var(--radius-full);
  cursor: pointer;
  letter-spacing: 0.02em;
  box-shadow: 0 4px 24px rgba(109,40,217,0.45), 0 1px 0 rgba(255,255,255,0.1) inset;
  transition: transform var(--t-fast), box-shadow var(--t-fast), background var(--t-normal);
  position: relative;
  overflow: hidden;
}

.btn-primary::before {
  content: '';
  position: absolute;
  inset: 0;
  background: linear-gradient(135deg, rgba(255,255,255,0.12), transparent);
  border-radius: inherit;
  pointer-events: none;
}

.btn-primary:hover {
  transform: translateY(-2px);
  box-shadow: 0 8px 30px rgba(109,40,217,0.55), 0 1px 0 rgba(255,255,255,0.1) inset;
}

.btn-primary:active {
  transform: translateY(0);
  box-shadow: 0 2px 10px rgba(109,40,217,0.35);
}

.btn-primary.btn-stop {
  background: linear-gradient(135deg, #6b1010 0%, #991b1b 100%);
  box-shadow: 0 4px 24px rgba(153,27,27,0.45);
}

.btn-primary.btn-stop:hover {
  box-shadow: 0 8px 30px rgba(153,27,27,0.55);
}

.btn-icon {
  font-size: 1.1rem;
  transition: transform var(--t-fast);
}

.btn-primary:hover .btn-icon {
  transform: scale(1.15);
}

/* ── Info panel ──────────────────────────────────────────────── */
.info-panel {
  display: flex;
  flex-wrap: wrap;
  justify-content: center;
  gap: var(--space-md);
}

.info-item {
  display: flex;
  align-items: center;
  gap: var(--space-xs);
  font-size: 0.75rem;
  color: var(--clr-text-3);
  font-weight: 500;
}

.info-icon {
  font-size: 0.85rem;
}

/* ── Footer ──────────────────────────────────────────────────── */
.app-footer {
  text-align: center;
  padding: var(--space-md) 0 var(--space-xl);
  font-size: 0.72rem;
  color: var(--clr-text-3);
  letter-spacing: 0.04em;
  border-top: 1px solid var(--clr-border);
  margin-top: auto;
}

/* ── Responsive ──────────────────────────────────────────────── */
@media (max-width: 480px) {
  .key.white { width: 34px; height: 116px; margin: 0 1px; }
  .key.black { width: 22px; height: 72px; }
  .keyboard  { height: 116px; }

  .key-label { font-size: 0.52rem; }
  .key.black .key-label { font-size: 0.44rem; }

  .note-display-card { padding: var(--space-lg) var(--space-md) var(--space-md); }
  .keyboard-section  { padding: var(--space-lg) var(--space-sm) var(--space-md); }

  .btn-primary { padding: 0.75rem 1.75rem; font-size: 0.95rem; }
}

@media (max-width: 360px) {
  .key.white { width: 28px; height: 100px; }
  .key.black { width: 18px; height: 62px; }
  .keyboard  { height: 100px; }
}

/* ── Utility ─────────────────────────────────────────────────── */
.visually-hidden {
  position: absolute;
  width: 1px; height: 1px;
  padding: 0; margin: -1px;
  overflow: hidden;
  clip: rect(0,0,0,0);
  white-space: nowrap;
  border: 0;
}