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

:root {
  --bg: #281466;
  --circle: #ffce00;
  --glow: rgba(255, 206, 0, 0.3);
  --text: rgba(255, 255, 255, 0.7);
  --panel-bg: rgba(0, 0, 0, 0.85);
  --panel-text: rgba(255, 255, 255, 0.9);
  --panel-muted: rgba(255, 255, 255, 0.5);
  --panel-border: rgba(255, 255, 255, 0.1);
}

html,
body {
  height: 100%;
  overflow: hidden;
  font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', system-ui, sans-serif;
  -webkit-font-smoothing: antialiased;
  background: var(--bg);
  color: var(--text);
  transition: background 0.6s ease;
  user-select: none;
  -webkit-user-select: none;
  touch-action: manipulation;
}

/* Main layout */
.app {
  display: grid;
  place-items: center;
  height: 100%;
  width: 100%;
  position: relative;
}

/* Breathing circle */
.circle {
  width: min(85vw, 85vh);
  height: min(85vw, 85vh);
  border-radius: 50%;
  background: radial-gradient(circle at 48% 48%, var(--circle) 0%, color-mix(in srgb, var(--circle), #000 15%) 80%);
  box-shadow: 0 0 80px 30px var(--glow), inset 0 0 0 1px rgba(255,255,255,0.05);
  transform: scale(0.25);
  will-change: transform;
  filter: url(#wobble) blur(1.5px);
  -webkit-filter: url(#wobble) blur(1.5px);
  transition: box-shadow 0.8s ease, background 0.6s ease;
}

/* Text cue */
.text-cue {
  position: absolute;
  font-size: clamp(1rem, 3vw, 1.5rem);
  font-weight: 300;
  letter-spacing: 0.2em;
  text-transform: uppercase;
  color: var(--text);
  opacity: 0;
  transition: opacity 0.4s ease;
  pointer-events: none;
}

/* Gear button */
.gear-btn {
  position: fixed;
  top: 1rem;
  left: 1rem;
  z-index: 100;
  background: none;
  border: none;
  cursor: pointer;
  opacity: 0.25;
  transition: opacity 0.3s ease;
  padding: 0.5rem;
  color: var(--text);
}

.gear-btn:hover,
.gear-btn:focus-visible {
  opacity: 0.7;
}

.gear-btn svg {
  width: 22px;
  height: 22px;
  fill: currentColor;
}

/* Settings overlay */
.settings-overlay {
  position: fixed;
  inset: 0;
  background: rgba(0, 0, 0, 0.4);
  z-index: 200;
  opacity: 0;
  pointer-events: none;
  transition: opacity 0.3s ease;
  backdrop-filter: blur(4px);
  -webkit-backdrop-filter: blur(4px);
}

.settings-overlay.open {
  opacity: 1;
  pointer-events: auto;
}

/* Settings panel */
.settings-panel {
  position: fixed;
  top: 0;
  left: 0;
  bottom: 0;
  width: min(340px, 85vw);
  background: var(--panel-bg);
  z-index: 300;
  transform: translateX(-100%);
  transition: transform 0.35s cubic-bezier(0.4, 0, 0.2, 1);
  overflow-y: auto;
  overscroll-behavior: contain;
  padding: 1.5rem;
  color: var(--panel-text);
}

.settings-panel.open {
  transform: translateX(0);
}

.settings-header {
  display: flex;
  justify-content: space-between;
  align-items: center;
  margin-bottom: 1.5rem;
}

.settings-header h2 {
  font-size: 1.2rem;
  font-weight: 500;
  letter-spacing: 0.05em;
}

#settings-close {
  background: none;
  border: none;
  color: var(--panel-muted);
  font-size: 1.5rem;
  cursor: pointer;
  padding: 0.25rem 0.5rem;
  line-height: 1;
}

.settings-section {
  margin-bottom: 1.5rem;
}

.settings-section h3 {
  font-size: 0.7rem;
  text-transform: uppercase;
  letter-spacing: 0.15em;
  color: var(--panel-muted);
  margin-bottom: 0.75rem;
  font-weight: 500;
}

/* Pattern list */
.pattern-list {
  display: flex;
  flex-direction: column;
  gap: 0.25rem;
}

.pattern-option {
  display: flex;
  align-items: center;
  gap: 0.5rem;
  padding: 0.6rem 0.75rem;
  border-radius: 8px;
  cursor: pointer;
  transition: background 0.2s ease;
}

.pattern-option:hover {
  background: rgba(255, 255, 255, 0.05);
}

.pattern-option.active {
  background: rgba(255, 255, 255, 0.1);
}

.pattern-option input[type='radio'] {
  display: none;
}

.pattern-name {
  flex: 1;
  font-size: 0.9rem;
}

.pattern-desc {
  font-size: 0.75rem;
  color: var(--panel-muted);
  font-variant-numeric: tabular-nums;
}

/* Custom sliders */
.custom-section {
  padding-left: 0.25rem;
}

.slider-row {
  display: flex;
  align-items: center;
  gap: 0.5rem;
  margin-bottom: 0.5rem;
}

.slider-label {
  width: 5.5rem;
  font-size: 0.8rem;
  color: var(--panel-muted);
}

.custom-slider {
  flex: 1;
  -webkit-appearance: none;
  appearance: none;
  height: 4px;
  border-radius: 2px;
  background: rgba(255, 255, 255, 0.15);
  outline: none;
}

.custom-slider::-webkit-slider-thumb {
  -webkit-appearance: none;
  appearance: none;
  width: 16px;
  height: 16px;
  border-radius: 50%;
  background: var(--panel-text);
  cursor: pointer;
}

.custom-slider::-moz-range-thumb {
  width: 16px;
  height: 16px;
  border-radius: 50%;
  background: var(--panel-text);
  border: none;
  cursor: pointer;
}

.slider-value {
  width: 2.5rem;
  text-align: right;
  font-size: 0.8rem;
  font-variant-numeric: tabular-nums;
  color: var(--panel-muted);
}

/* Palette selector */
.palette-list {
  display: flex;
  flex-wrap: wrap;
  gap: 0.5rem;
}

.palette-option {
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 0.3rem;
  background: none;
  border: 2px solid transparent;
  border-radius: 10px;
  padding: 0.4rem;
  cursor: pointer;
  transition: border-color 0.2s ease;
}

.palette-option.active {
  border-color: rgba(255, 255, 255, 0.4);
}

.palette-swatch {
  width: 40px;
  height: 40px;
  border-radius: 8px;
  display: grid;
  place-items: center;
}

.palette-dot {
  width: 16px;
  height: 16px;
  border-radius: 50%;
}

.palette-name {
  font-size: 0.6rem;
  color: var(--panel-muted);
  letter-spacing: 0.05em;
}

/* Toggle switch */
.setting-row {
  display: flex;
  justify-content: space-between;
  align-items: center;
  padding: 0.5rem 0;
  font-size: 0.9rem;
}

.toggle {
  position: relative;
  display: inline-block;
  width: 40px;
  height: 22px;
}

.toggle input {
  opacity: 0;
  width: 0;
  height: 0;
}

.toggle-slider {
  position: absolute;
  inset: 0;
  background: rgba(255, 255, 255, 0.15);
  border-radius: 22px;
  cursor: pointer;
  transition: background 0.3s ease;
}

.toggle-slider::before {
  content: '';
  position: absolute;
  top: 3px;
  left: 3px;
  width: 16px;
  height: 16px;
  border-radius: 50%;
  background: white;
  transition: transform 0.3s ease;
}

.toggle input:checked + .toggle-slider {
  background: rgba(255, 255, 255, 0.4);
}

.toggle input:checked + .toggle-slider::before {
  transform: translateX(18px);
}

/* Reduced motion */
@media (prefers-reduced-motion: reduce) {
  .circle {
    filter: none;
    transition: none;
  }

  .settings-panel {
    transition: none;
  }

  .settings-overlay {
    transition: none;
  }
}

/* Scrollbar styling for settings */
.settings-panel::-webkit-scrollbar {
  width: 4px;
}

.settings-panel::-webkit-scrollbar-track {
  background: transparent;
}

.settings-panel::-webkit-scrollbar-thumb {
  background: rgba(255, 255, 255, 0.15);
  border-radius: 2px;
}