/* ============================================
   Ambient Drone Generator — Hardware Synth UI
   ============================================ */

/* Font */
@font-face {
  font-family: 'Iosevka';
  src: url('fonts/iosevka-light.woff2') format('woff2');
  font-weight: 300;
  font-style: normal;
  font-display: swap;
}

/* Design Tokens */
:root {
  --bg: #161513;
  --bg-panel: #1c1a17;
  --bg-inset: #121110;
  --text: #e6e3e1;
  --text-secondary: #a09a92;
  --text-muted: #6d685f;
  --accent: #f0b105;
  --accent-dim: rgba(240, 177, 5, 0.25);
  --border: #33312e;
  --border-light: #3d3a36;
  --radius-panel: 24px;
  --radius-control: 8px;
  --font: 'IBM Plex Mono', 'SF Mono', 'Fira Code', 'Cascadia Code', monospace;
  --transition: 0.2s ease;
}

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

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

/* Base */
html {
  font-size: 16px;
}

body {
  font-family: var(--font);
  font-weight: 300;
  background: var(--bg);
  color: var(--text);
  min-height: 100vh;
  line-height: 1.4;
  overflow-x: hidden;
  text-transform: uppercase;
  letter-spacing: 0.04em;
}

a:link, a:visited {
  color: var(--accent);
  transition: 0.4s ease-in-out;
  border-radius: 2px;
  padding: 2px;
  margin: -2px;
}
a:hover, a:active {
  background-color: var(--accent);
  text-decoration: none;
  color: var(--bg);
}

hr {
  margin-block: 1rem;
  border: 1.5px solid var(--border);
}

.text-muted {
  color: var(--text-muted);
}

/* ============ App Container ============ */

.app {
  position: relative;
  z-index: 1;
  max-width: 1100px;
  margin: 0 auto;
  padding: 1.5rem 1.5rem 120px;
  min-height: 100vh;
}

/* ============ Mode (hidden in hardware UI) ============ */

.mode-panel {
  display: none;
}

.mode-panel.active {
  display: block;
}

/* ============ Rack Layout ============ */

.rack {
  display: grid;
  gap: 1rem;
}

.rack__top {
  display: grid;
  grid-template-columns: 1fr auto;
  gap: 1rem;
  align-items: stretch;
}

.rack__layers {
  display: flex;
  justify-content: flex-end;
  gap: 1rem;
}

/* ============ Header ============ */

.header {
  display: flex;
  flex-direction: column;
  align-items: flex-start;
  gap: 1rem;
  padding: 1rem;
}

.header h1 {
  font-size: 3.75rem;
  font-weight: 300;
  letter-spacing: -0.003125em;
  color: var(--text);
  line-height: 1.2;
  text-transform: none;
  white-space: nowrap;
}

.tagline {
  font-size: 1.125rem;
  color: var(--text);
  margin-top: 0.25rem;
}

/* ============ Panels ============ */

.panel {
  /* background: var(--bg-panel); */
  border: 1.5px solid var(--border);
  border-radius: var(--radius-panel);
  padding: 1rem;
}

.panel__label {
  display: block;
  font-size: 0.625rem;
  color: var(--text-muted);
  letter-spacing: 0.1em;
  margin-bottom: 0.75rem;
}

/* ============ Effects Panel ============ */

.panel--effects {
  display: flex;
  flex-direction: column;
}

.effects-row {
  display: flex;
  gap: 1rem;
  flex: 1;
  align-items: flex-end;
}

.control-stage {
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 0.5rem;
  /* flex: 1; */
}

.control-stage.bypassed {
  opacity: 0.35;
}

.control-stage.bypassed .fader {
  pointer-events: none;
}

/* Hide native range inputs that have fader replacements */
input[data-fader] {
  position: absolute;
  opacity: 0;
  pointer-events: none;
  width: 0;
  height: 0;
}

/* ============ Bypass Toggle (small switch) ============ */

.bypass-toggle {
  position: relative;
  width: 24px;
  height: 24px;
  background: none;
  border: 1.5px solid var(--border);
  border-radius: 50%;
  cursor: pointer;
  transition: all var(--transition);
  padding: 0;
  flex-shrink: 0;
}

/* Hide text, keep for screen readers */
.bypass-toggle .toggle-on,
.bypass-toggle .toggle-off {
  position: absolute;
  width: 1px;
  height: 1px;
  overflow: hidden;
  clip: rect(0, 0, 0, 0);
}

/* Dot indicator */
.bypass-toggle::after {
  content: '';
  position: absolute;
  top: 50%;
  left: 50%;
  transform: translate(-50%, -50%);
  width: 8px;
  height: 8px;
  border-radius: 50%;
  background: var(--text-muted);
  transition: background var(--transition);
}

.bypass-toggle.active {
  border-color: var(--accent);
}

.bypass-toggle.active::after {
  background: var(--accent);
  box-shadow: 0 0 6px var(--accent-dim);
}

.bypass-toggle:hover {
  border-color: var(--accent);
}

.bypass-toggle:focus-visible {
  outline: 2px solid var(--accent);
  outline-offset: 2px;
}

/* ============ Vertical Fader ============ */

.fader {
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 0.375rem;
  width: 72px;
  user-select: none;
}

.fader__track {
  position: relative;
  width: 72px;
  height: 160px;
  background: var(--bg-inset);
  border: 1.5px solid var(--text-muted);
  border-radius: var(--radius-control);
  cursor: pointer;
  touch-action: none;
  overflow: hidden;
}

.fader__fill {
  position: absolute;
  bottom: 32px;
  left: 0;
  width: 100%;
  background: var(--text);
  transition: height 0.05s linear;
}

.fader__readout {
  position: absolute;
  left: 0;
  right: 0;
  bottom: 0;
  height: 32px;
  display: flex;
  align-items: center;
  justify-content: center;
  background: var(--bg);
  z-index: 1;
  font-family: var(--font);
  font-size: 1.125rem;
  font-weight: 300;
  color: var(--text);
  pointer-events: none;
  letter-spacing: 0.02em;
  font-variant-numeric: tabular-nums;
}

.fader__label {
  font-size: 1.125rem;
  color: var(--text);
  letter-spacing: -0.00625em;
  text-align: center;
  margin-top: 0.125rem;
}

.fader:focus-visible {
  outline: none;
}

.fader:focus-visible .fader__track {
  box-shadow: 0 0 0 2px var(--accent);
}

/* ============ Fader Row (inside panels) ============ */

.fader-row {
  display: flex;
  gap: 16px;
  padding-top: 0.75rem;
}

/* ============ Layer Toggle (power button) ============ */

.layer-toggle {
  display: flex;
  align-items: center;
  gap: 8px;
  padding: 2px;
  background: var(--text-muted);
  border: none;
  border-radius: var(--radius-control);
  cursor: pointer;
  flex-shrink: 0;
  font-family: var(--font);
  font-weight: 300;
  transition: background var(--transition);
  width: 72px;
}

section.has-content .layer-toggle {
  justify-content: flex-end;
}

.layer-toggle:hover {
  opacity: 0.85;
}

.layer-toggle:focus-visible {
  outline: 2px solid var(--accent);
  outline-offset: 2px;
}

.has-content .layer-toggle {
  background: var(--accent);
}

/* Power symbol indicators */
.toggle-on-ind,
.toggle-off-ind {
  font-size: 0.875rem;
  color: rgba(0, 0, 0, 0.45);
  flex-shrink: 0;
  line-height: 1;
}

.layer-toggle .toggle-on-ind { display: none; }
.layer-toggle .toggle-off-ind { display: block; }
.has-content .layer-toggle .toggle-on-ind { display: block; }
.has-content .layer-toggle .toggle-off-ind { display: none; }

/* Layer ID inside toggle */
.toggle-id {
  display: flex;
  align-items: center;
  justify-content: center;
  padding: 0 8px;
  height: 44px;
  min-width: 44px;
  background: var(--bg);
  border-radius: calc(var(--radius-control) - 2px);
  font-size: 1.5rem;
  color: var(--text);
  line-height: 1;
}

/* ============ Layer Panel ============ */

.panel--layer {
  display: flex;
  flex-direction: column;
  align-items: center;
}

/* Layer header width = 5 faders × 72px + 4 gaps × 16px */
.panel--layer .layer-header {
  width: calc(5 * 72px + 4 * 16px);
}

/* ============ Layer Header ============ */

.layer-header {
  display: flex;
  align-items: center;
  gap: 1rem;
  margin-bottom: 0.625rem;
}

/* Hidden — JS still references these elements */
.layer-name,
.layer-clear {
  display: none;
}

/* Sequencer layer-name is visible and pushes clear button to the right */
.sequencer-layer .layer-name {
  display: block;
  flex: 1;
  font-size: 1.125rem;
  color: var(--text-muted);
  letter-spacing: -0.00625em;
}

.sequencer-layer .layer-clear {
  display: flex;
  align-items: center;
  justify-content: center;
  font-family: var(--font);
  font-size: 0.875rem;
  letter-spacing: -0.00625em;
  color: var(--text-muted);
  background: none;
  border: none;
  cursor: pointer;
  padding: 0;
  transition: color var(--transition);
}
.sequencer-layer.has-content .layer-clear{
  color: var(--text);
}

.sequencer-layer .layer-clear:hover {
  color: var(--accent);
}

/* ============ Layer Controls (Chord Select) ============ */

.layer-controls {
  flex: 1;
}

.layer-chord {
  width: 100%;
  height: 48px;
  padding: 0 2.5rem 0 0.875rem;
  font-family: var(--font);
  font-size: 1.125rem;
  font-weight: 300;
  letter-spacing: 0.04em;
  text-transform: uppercase;
  color: var(--text);
  background: var(--bg-inset);
  border: 1.5px solid var(--text-muted);
  border-radius: var(--radius-control);
  cursor: pointer;
  appearance: none;
  background-image: url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' width='10' height='10' viewBox='0 0 12 12'%3E%3Cpath fill='%236d685f' d='M6 8L1 3h10z'/%3E%3C/svg%3E");
  background-repeat: no-repeat;
  background-position: right 0.875rem center;
}

.layer-chord:focus-visible {
  outline: 2px solid var(--accent);
  outline-offset: 2px;
}

.layer-chord option {
  background: var(--bg-panel);
  color: var(--text);
}

/* ============ Sequencer Panel ============ */

.panel--sequencer {
  display: grid;
  grid-template-columns: auto 1fr;
  gap: 1.25rem;
}

.sequencer-left {
  display: flex;
  flex-direction: column;
  min-width: 180px;
}

.sequencer-right {
  display: flex;
  flex-direction: column;
  min-width: 0;
}

.sequencer-options {
  display: none;
}

/* ============ Sequencer Grid ============ */

.sequencer-grid {
  position: relative;
  height: 120px;
  background: var(--bg-inset);
  border: 1.5px solid var(--border);
  border-radius: var(--radius-control) var(--radius-control) 0 0;
  border-bottom: none;
  overflow: hidden;
}

@keyframes flashLimit {
  0%   { box-shadow: inset 0 0 0 2px var(--accent); }
  50%  { box-shadow: inset 0 0 0 2px transparent; }
  100% { box-shadow: inset 0 0 0 2px var(--accent); }
}

.sequencer-grid.at-limit {
  animation: flashLimit 0.4s ease;
}

.grid-lines {
  position: absolute;
  top: 0;
  left: 0;
  right: 0;
  bottom: 0;
  display: flex;
  pointer-events: none;
}

.grid-line {
  flex: 1;
  border-right: 1px solid var(--border-light);
}

.grid-line.beat {
  background: var(--border);
}

.grid-line:last-child {
  border-right: none;
}

.grid-playhead {
  position: absolute;
  top: 0;
  left: 0;
  width: 2px;
  height: 100%;
  background: var(--accent);
  box-shadow: 0 0 8px var(--accent-dim);
  z-index: 10;
  pointer-events: none;
}

.grid-notes {
  position: absolute;
  top: 0;
  left: 0;
  right: 0;
  bottom: 0;
}

.grid-info {
  display: flex;
  padding: 0 0 0.5rem 0;
}

.beat-label {
  flex: 1;
  text-align: center;
  font-size: 0.5625rem;
  color: var(--text-muted);
}

/* ============ Note Blocks ============ */

.note-block {
  position: absolute;
  height: 30px;
  width: calc(6.25% - 8px);
  margin-left: 2px;
  background: var(--accent);
  border-radius: var(--radius-control);
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 1rem;
  font-weight: 300;
  color: #161513;
  cursor: grab;
  user-select: none;
  box-shadow: 0 2px 8px rgba(0, 0, 0, 0.3);
  transition: transform 0.1s ease, box-shadow 0.1s ease;
  z-index: 5;
}

.note-block:hover {
  transform: scale(1.05);
  box-shadow: 0 4px 12px rgba(0, 0, 0, 0.4);
}

.note-block.stacked {
  box-shadow: 0 1px 4px rgba(0, 0, 0, 0.4);
  transform: none;
}

.note-block.stacked:hover {
  transform: none;
}

.note-block.dragging {
  cursor: grabbing;
  transform: scale(1.1);
  box-shadow: 0 6px 20px rgba(0, 0, 0, 0.5);
  z-index: 20;
  opacity: 0.9;
}

.note-block.playing {
  animation: note-pulse 0.3s ease-out;
}

@keyframes note-pulse {
  0% {
    transform: scale(1);
    box-shadow: 0 2px 8px rgba(0, 0, 0, 0.3);
  }
  50% {
    transform: scale(1.15);
    box-shadow: 0 0 20px var(--accent-dim);
  }
  100% {
    transform: scale(1);
    box-shadow: 0 2px 8px rgba(0, 0, 0, 0.3);
  }
}

.note-block .delete-note {
  position: absolute;
  top: -6px;
  right: -6px;
  width: 16px;
  height: 16px;
  background: #ef4444;
  border: none;
  border-radius: 50%;
  color: white;
  font-size: 10px;
  line-height: 1;
  cursor: pointer;
  opacity: 0;
  transition: opacity 0.2s ease;
  display: flex;
  align-items: center;
  justify-content: center;
}

.note-block:hover .delete-note {
  opacity: 1;
}

/* ============ Keyboard ============ */

.keyboard {
  position: relative;
  display: flex;
  flex: 1;
  background: var(--bg-inset);
  border: 1.5px solid var(--border);
  border-top: none;
  border-radius: 0 0 var(--radius-control) var(--radius-control);
  min-height: 140px;
  overflow: hidden;
}

.key {
  position: relative;
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: flex-start;
  padding-top: 0.625rem;
  cursor: pointer;
  transition: background var(--transition);
  user-select: none;
}

.key.white {
  flex: 1;
  background: #E6E3E1;
  border-right: 1px solid var(--border);
}

.key.white:last-of-type {
  border-right: none;
}

.key.white:hover {
  background: #ece9e6;
}

.key.white.active {
  background: var(--accent);
}

.key.black {
  position: absolute;
  top: 0;
  width: 32px;
  height: 52%;
  background: #161513;
  border-radius: 0 0 6px 6px;
  z-index: 1;
}

.key.black:hover {
  background: #252321;
}

.key.black.active {
  background: var(--accent);
}

.note-label {
  font-family: var(--font);
  font-size: 1.125rem;
  font-weight: 300;
  color: #161513;
  line-height: 1;
}

.key.black .note-label {
  color: #6D685F;
}

.key.white.active .note-label,
.key.black.active .note-label {
  color: #161513;
}

/* ============ Play Button ============ */

.play-btn {
  display: flex;
  align-items: center;
  gap: 8px;
  padding: 2px;
  background: var(--text-muted);
  border: none;
  border-radius: var(--radius-control);
  cursor: pointer;
  font-family: var(--font);
  font-weight: 300;
  flex-shrink: 0;
  transition: background var(--transition);
  width: 72px;
}

.play-btn:hover {
  opacity: 0.85;
}

.play-btn:focus-visible {
  outline: 2px solid var(--accent);
  outline-offset: 2px;
}

.play-btn.playing {
  background: var(--accent);
  justify-content: flex-end;
}

/* I/O indicators */
.play-btn .toggle-on-ind { display: none; }
.play-btn .toggle-off-ind { display: block; }
.play-btn.playing .toggle-on-ind { display: block; }
.play-btn.playing .toggle-off-ind { display: none; }

/* SVG icons inside the toggle-id box */
.play-icon,
.pause-icon {
  width: 20px;
  height: 20px;
  color: var(--bg);
}

.play-icon {
  margin-left: 2px; /* optical center for play triangle */
}

.play-btn .pause-icon { display: none; }
.play-btn.playing .play-icon { display: none; }
.play-btn.playing .pause-icon { display: block; }

/* ============ Layer states ============ */

.layer.has-content {
  border-color: var(--accent);
}

.sequencer-layer {
  border-color: var(--border);
}

.sequencer-layer.has-content {
  border-color: var(--accent);
}

/* ============ Footer ============ */

footer {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 1rem;
  padding: 0.75rem 1.5rem;
  color: var(--text-muted);
  font-size: 0.75rem;
}

footer a {
  color: var(--text-muted);
}

footer a:hover {
  color: var(--text);
}

.info-btn {
  background: none;
  border: 1.5px solid var(--accent-dim);
  color: var(--text);
  font-family: inherit;
  font-size: 0.75rem;
  padding: 0.2rem 0.6rem;
  border-radius: 3px;
  cursor: pointer;
  transition: border-color var(--transition), color var(--transition);
  white-space: nowrap;
}

.info-btn:hover {
  background: var(--accent);
  border-color: var(--accent);
  color: var(--bg);
}

.info-btn:focus-visible {
  outline: 2px solid var(--accent);
  outline-offset: 2px;
}

/* ============ Info Modal ============ */

.info-overlay {
  position: fixed;
  inset: 0;
  background: rgba(0, 0, 0, 0.7);
  z-index: 100;
  display: flex;
  align-items: center;
  justify-content: center;
  padding: 1.5rem;
}

.info-overlay[hidden] {
  display: none;
}

.info-modal {
  position: relative;
  background: var(--bg-panel);
  border: 1.5px solid var(--border-light);
  border-radius: 1rem;
  width: 100%;
  max-width: 560px;
  max-height: 80vh;
  display: flex;
  flex-direction: column;
}

.info-modal__close {
  position: absolute;
  top: 0.75rem;
  right: 0.75rem;
  background: none;
  border: none;
  color: var(--text-muted);
  font-size: 1.25rem;
  line-height: 1;
  cursor: pointer;
  padding: 0.25rem 0.5rem;
  transition: color var(--transition);
}

.info-modal__close:hover {
  color: var(--text);
}

.info-modal__close:focus-visible {
  outline: 2px solid var(--accent);
  outline-offset: 2px;
  border-radius: 2px;
}

.info-modal__body {
  overflow-y: auto;
  padding: 1.75rem 2rem 2rem;
  font-size: 1.125rem;
  line-height: 1.6;
  color: var(--text);
  text-transform: none;
  font-family: system-ui, -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, Oxygen, Ubuntu, Cantarell, 'Open Sans', 'Helvetica Neue', sans-serif;
}

.info-modal__body h2 {
  font-size: 1.25rem;
  font-weight: 600;
  color: var(--text);
  margin: 0 0 1.25rem;
  padding-right: 2rem; /* avoid close button overlap */
}

.info-modal__body h3 {
  font-size: 1.25rem;
  font-weight: 600;
  color: var(--text);
  text-transform: uppercase;
  letter-spacing: 0.06em;
  margin: 1.5rem 0 0.5rem;
}

.info-modal__body h3:first-of-type {
  margin-top: 0;
}

.info-modal__body h4 {
  font-size: 1.25rem;
  font-weight: 600;
  color: var(--text);
  margin: 1rem 0 0.4rem;
}

.info-modal__body p {
  margin: 0 0 0.6rem;
}

.info-modal__body ul {
  margin: 0 0 0.6rem;
  padding-left: 1.25rem;
}

.info-modal__body li {
  margin-bottom: 0.3rem;
}

.info-modal__body code {
  font-family: monospace;
  font-size: 0.8125rem;
  background: var(--bg-inset);
  border: 1px solid var(--border);
  border-radius: 2px;
  padding: 0.1em 0.35em;
  color: var(--text);
}

/* ============ Responsive (<768px) ============ */

@media (max-width: 768px) {
  .app {
    padding: 1rem 0.75rem 120px;
  }

  .rack__top {
    grid-template-columns: 1fr;
  }

  .rack__layers {
    flex-direction: column;
  }

  .panel--sequencer {
    grid-template-columns: 1fr;
  }

  .sequencer-left {
    min-width: 0;
  }

  .sequencer-left .fader-row {
    justify-content: flex-start;
  }

  .header {
    padding: 1rem;
    flex-direction: column;
    justify-content: space-between;
    align-items: start;
  }

  .panel--layer,
  .panel--effects {
    align-items: start;
  }
  .fader__track {
    height: 120px;
  }
}