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

body, html {
  width: 100%;
  height: 100%;
  overflow: hidden;
  background-color: #000;
  font-family: -apple-system, BlinkMacSystemFont, "SF Pro Display", "Segoe UI", Roboto, Helvetica, Arial, sans-serif;
  -webkit-font-smoothing: antialiased;
}

canvas {
  display: block;
  position: absolute;
  top: 0;
  left: 0;
  width: 100%;
  height: 100%;
}

/* ---- Liquid Glass Overlay ---- */

#ui-overlay {
  position: absolute;
  inset: 0;
  display: flex;
  flex-direction: column;
  justify-content: center;
  align-items: center;
  z-index: 100;
  background: rgba(0, 0, 0, 0.55);
  backdrop-filter: blur(40px) saturate(180%);
  -webkit-backdrop-filter: blur(40px) saturate(180%);
  transition: opacity 0.6s ease;
  color: white;
  text-align: center;
  padding: 32px;
}

#ui-overlay.hidden {
  opacity: 0;
  pointer-events: none;
}

#ui-overlay h1 {
  font-size: clamp(32px, 6vw, 56px);
  font-weight: 600;
  letter-spacing: -0.02em;
  margin-bottom: 12px;
  background: linear-gradient(180deg, rgba(255,255,255,0.95) 0%, rgba(255,255,255,0.7) 100%);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
}

#ui-overlay p {
  font-size: clamp(14px, 2.5vw, 17px);
  line-height: 1.5;
  opacity: 0.6;
  max-width: 360px;
  margin-bottom: 32px;
}

#begin-btn {
  padding: 14px 40px;
  font-size: 17px;
  font-weight: 600;
  color: #000;
  background: rgba(255, 255, 255, 0.9);
  border: 0.5px solid rgba(255, 255, 255, 0.3);
  border-radius: 100px;
  cursor: pointer;
  backdrop-filter: blur(10px);
  -webkit-backdrop-filter: blur(10px);
  box-shadow: 0 4px 24px rgba(0, 0, 0, 0.2), inset 0 1px 0 rgba(255, 255, 255, 0.5);
  transition: transform 0.15s ease, background 0.2s ease, box-shadow 0.2s ease;
  letter-spacing: -0.01em;
}

#begin-btn:hover {
  background: rgba(255, 255, 255, 1);
  box-shadow: 0 6px 32px rgba(0, 0, 0, 0.25), inset 0 1px 0 rgba(255, 255, 255, 0.6);
}

#begin-btn:active {
  transform: scale(0.96);
}

#status-msg {
  margin-top: 16px;
  font-size: 13px;
  opacity: 0.4;
}

/* ---- Debug ---- */

#debug-info {
  position: absolute;
  bottom: 12px;
  left: 12px;
  color: rgba(255, 255, 255, 0.4);
  font-family: "SF Mono", "Menlo", "Consolas", monospace;
  font-size: 11px;
  pointer-events: none;
  z-index: 50;
}

#key-hints {
  position: absolute;
  top: 10px;
  left: 50%;
  transform: translateX(-50%);
  display: flex;
  gap: 16px;
  z-index: 50;
  pointer-events: none;
}

.hint {
  font-family: -apple-system, BlinkMacSystemFont, "SF Pro Display", sans-serif;
  font-size: 11px;
  color: rgba(255, 255, 255, 0.35);
  letter-spacing: 0.02em;
}

.hint kbd {
  display: inline-block;
  padding: 1px 6px;
  font-family: "SF Mono", "Menlo", "Consolas", monospace;
  font-size: 10px;
  color: rgba(255, 255, 255, 0.5);
  background: rgba(255, 255, 255, 0.08);
  border: 1px solid rgba(255, 255, 255, 0.12);
  border-radius: 4px;
  backdrop-filter: blur(4px);
  -webkit-backdrop-filter: blur(4px);
}

/* ---- Glass Control Buttons ---- */

.glass-btn {
  display: flex;
  align-items: center;
  gap: 7px;
  padding: 10px 18px;
  font-size: 14px;
  font-weight: 500;
  font-family: -apple-system, BlinkMacSystemFont, "SF Pro Display", "Segoe UI", Roboto, Helvetica, Arial, sans-serif;
  color: rgba(255, 255, 255, 0.85);
  background: rgba(255, 255, 255, 0.08);
  border: 0.5px solid rgba(255, 255, 255, 0.15);
  border-radius: 100px;
  cursor: pointer;
  backdrop-filter: blur(20px);
  -webkit-backdrop-filter: blur(20px);
  box-shadow: 0 4px 16px rgba(0, 0, 0, 0.15), inset 0 1px 0 rgba(255, 255, 255, 0.1);
  transition: background 0.2s ease, box-shadow 0.2s ease, transform 0.15s ease, opacity 0.3s ease;
  letter-spacing: -0.01em;
  white-space: nowrap;
  -webkit-font-smoothing: antialiased;
}

.glass-btn:hover {
  background: rgba(255, 255, 255, 0.14);
  box-shadow: 0 6px 24px rgba(0, 0, 0, 0.2), inset 0 1px 0 rgba(255, 255, 255, 0.15);
}

.glass-btn:active {
  transform: scale(0.95);
}

.glass-btn svg {
  flex-shrink: 0;
  opacity: 0.7;
}

/* Eye icon — hide UI toggle */
#btn-hide-ui {
  position: absolute;
  top: 18px;
  right: 18px;
  z-index: 120;
  padding: 10px;
}

/* Upload button — top right, next to eye icon */
#btn-upload {
  position: absolute;
  top: 18px;
  right: 64px;
  z-index: 120;
  padding: 10px;
}

#btn-hide-ui.icon-btn {
  padding: 10px;
  border-radius: 50%;
  width: 40px;
  height: 40px;
  justify-content: center;
}

.glass-btn.off {
  opacity: 0.35;
}

.glass-btn.off svg {
  opacity: 0.4;
}

/* Controls container */
#controls {
  position: absolute;
  bottom: 24px;
  right: 18px;
  display: flex;
  gap: 10px;
  z-index: 110;
  transition: opacity 0.3s ease, transform 0.3s ease;
}

#controls.hidden {
  opacity: 0;
  pointer-events: none;
  transform: translateY(8px);
}

/* Reset button hidden until veil first opened */
#btn-reset {
  opacity: 0;
  pointer-events: none;
  transition: opacity 0.4s ease, background 0.2s ease, box-shadow 0.2s ease, transform 0.15s ease;
}

#btn-reset.visible {
  opacity: 1;
  pointer-events: auto;
}

/* ---- Settings Panel ---- */

#settings-panel {
  position: absolute;
  bottom: 80px;
  right: 18px;
  z-index: 130;
  width: 220px;
  padding: 18px;
  background: rgba(20, 20, 20, 0.75);
  border: 0.5px solid rgba(255, 255, 255, 0.12);
  border-radius: 18px;
  backdrop-filter: blur(30px);
  -webkit-backdrop-filter: blur(30px);
  box-shadow: 0 8px 40px rgba(0, 0, 0, 0.3), inset 0 1px 0 rgba(255, 255, 255, 0.06);
  transition: opacity 0.25s ease, transform 0.25s ease;
  display: flex;
  flex-direction: column;
  gap: 16px;
}

#settings-panel.hidden {
  opacity: 0;
  pointer-events: none;
  transform: translateY(8px) scale(0.96);
}

.settings-section {
  display: flex;
  flex-direction: column;
  gap: 8px;
}

.settings-label {
  font-size: 11px;
  font-weight: 600;
  color: rgba(255, 255, 255, 0.4);
  text-transform: uppercase;
  letter-spacing: 0.06em;
}

/* Filter mode chips */
.filter-row {
  display: flex;
  gap: 6px;
  flex-wrap: wrap;
}

.filter-chip {
  padding: 6px 12px;
  font-size: 12px;
  font-weight: 500;
  font-family: inherit;
  color: rgba(255, 255, 255, 0.55);
  background: rgba(255, 255, 255, 0.06);
  border: 0.5px solid rgba(255, 255, 255, 0.1);
  border-radius: 100px;
  cursor: pointer;
  transition: all 0.2s ease;
  -webkit-font-smoothing: antialiased;
}

.filter-chip:hover {
  background: rgba(255, 255, 255, 0.1);
  color: rgba(255, 255, 255, 0.8);
}

.filter-chip.active {
  background: rgba(255, 255, 255, 0.18);
  color: #fff;
  border-color: rgba(255, 255, 255, 0.25);
  box-shadow: 0 0 12px rgba(255, 255, 255, 0.08);
}

/* Toggle switches */
.toggle-row {
  display: flex;
  align-items: center;
  justify-content: space-between;
}

.toggle-switch {
  width: 44px;
  height: 26px;
  border-radius: 13px;
  border: none;
  cursor: pointer;
  background: rgba(255, 255, 255, 0.12);
  position: relative;
  transition: background 0.25s ease;
  padding: 0;
}

.toggle-switch::after {
  content: '';
  position: absolute;
  top: 3px;
  left: 3px;
  width: 20px;
  height: 20px;
  border-radius: 50%;
  background: #fff;
  box-shadow: 0 1px 4px rgba(0, 0, 0, 0.3);
  transition: transform 0.25s ease;
}

.toggle-switch.on {
  background: rgba(255, 255, 255, 0.35);
}

.toggle-switch.on::after {
  transform: translateX(18px);
}

/* Volume slider */
.volume-slider {
  -webkit-appearance: none;
  appearance: none;
  width: 100%;
  height: 4px;
  border-radius: 2px;
  background: rgba(255, 255, 255, 0.12);
  outline: none;
  cursor: pointer;
}

.volume-slider::-webkit-slider-thumb {
  -webkit-appearance: none;
  appearance: none;
  width: 16px;
  height: 16px;
  border-radius: 50%;
  background: #fff;
  box-shadow: 0 1px 6px rgba(0, 0, 0, 0.3);
  cursor: pointer;
}

.volume-slider::-moz-range-thumb {
  width: 16px;
  height: 16px;
  border-radius: 50%;
  background: #fff;
  border: none;
  box-shadow: 0 1px 6px rgba(0, 0, 0, 0.3);
  cursor: pointer;
}