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

:root {
  --bg:            #111111;
  --grid-line:     #2e2e2e;
  --tile-border:   #2e2e2e;
  --tile-bg:       #1a1a1a;
  --tile-fg:       #909090;
  --prime-bg:      #1c1c1c;
  --prime-fg:      #ffffff;
  --prime-glow:    rgba(255, 255, 255, 0.25);
  --prime-glow2:   rgba(255, 255, 255, 0.08);
  --wave-color:    #aaff00;
  --lens-color:    rgba(170, 255, 0, 0.55);
  --composite-fg:  #3a3a3a;
  --composite-bg:  #111111;
  --ui-fg:         #666666;
  --ui-border:     #2a2a2a;
  --ui-bg:         #0f0f0f;
  --ui-hover-bg:   #1e1e1e;
  --one-fg:        #505050;
  --font-mono:     'IBM Plex Mono', 'Courier New', monospace;
  --font-ui:       'IBM Plex Sans', system-ui, sans-serif;
  --tile-size:      28px;
  --tile-gap:       2px;
  --tile-step:      30px;
  --tile-font-size: 10px;
  --header-h:       48px;
}

[data-theme="light"] {
  --bg:            #f2f0ea;
  --grid-line:     #dddad2;
  --tile-border:   #c8c4bc;
  --tile-bg:       #faf8f4;
  --tile-fg:       #555555;
  --prime-bg:      #f5f5f7;
  --prime-fg:      #111111;
  --prime-glow:    rgba(0, 0, 0, 0.12);
  --prime-glow2:   rgba(0, 0, 0, 0.04);
  --wave-color:    #f97316;
  --lens-color:    rgba(249, 115, 22, 0.55);
  --composite-fg:  #999999;
  --composite-bg:  #e8e8e8;
  --ui-fg:         #777799;
  --ui-border:     #c8c4bc;
  --ui-bg:         #eae8e2;
  --ui-hover-bg:   #dddad4;
  --one-fg:        #aaaaaa;
}

html, body {
  height: 100%;
  overflow: hidden;
  background-color: var(--bg);
  transition: background-color 0.35s;
}

body {
  display: flex;
  flex-direction: column;
  font-family: var(--font-ui);
  background-image: radial-gradient(circle, var(--grid-line) 1.5px, transparent 1.5px);
  background-size: var(--tile-step) var(--tile-size);
  background-position: 0 calc(50vh - var(--tile-size) / 2 - var(--header-h) / 2 + 1px);
  background-attachment: fixed;
}

/* ── Header ──────────────────────────────────────────────── */

#controls {
  flex-shrink: 0;
  height: var(--header-h);
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 0 20px;
  border-bottom: 1px solid var(--ui-border);
  background: var(--ui-bg);
  position: relative;
  z-index: 30;
  transition: background 0.35s, border-color 0.35s;
}

.controls-title {
  font-family: var(--font-mono);
  font-size: 10px;
  font-weight: 500;
  letter-spacing: 0.12em;
  color: var(--ui-fg);
  text-transform: uppercase;
}

.controls-group {
  display: flex;
  align-items: center;
  gap: 8px;
}

.controls-label {
  font-family: var(--font-mono);
  font-size: 13px;
  color: var(--ui-fg);
}

#max-n {
  width: 64px;
  font-family: var(--font-mono);
  font-size: 13px;
  padding: 4px 8px;
  background: var(--tile-bg);
  border: 1px solid var(--ui-border);
  color: var(--prime-fg);
  border-radius: 3px;
  text-align: center;
  outline: none;
  transition: background 0.35s, border-color 0.35s, color 0.35s;
}

#max-n:focus {
  border-color: var(--wave-color);
}

#reset-btn,
#theme-toggle,
.zoom-btn {
  font-family: var(--font-mono);
  font-size: 12px;
  padding: 4px 10px;
  background: var(--ui-bg);
  border: 1px solid var(--ui-border);
  color: var(--ui-fg);
  border-radius: 3px;
  cursor: pointer;
  transition: background 0.2s, color 0.2s, opacity 0.2s;
  letter-spacing: 0.04em;
}

#reset-btn:hover,
#theme-toggle:hover,
.zoom-btn:hover:not(:disabled) {
  background: var(--ui-hover-bg);
  color: var(--prime-fg);
}

.zoom-btn {
  font-size: 15px;
  padding: 2px 8px;
  line-height: 1;
}

.zoom-btn:disabled {
  opacity: 0.3;
  cursor: default;
}

.zoom-label {
  min-width: 3.8ch;
  text-align: center;
  font-size: 11px;
  letter-spacing: 0.05em;
  tabular-nums: all;
  font-variant-numeric: tabular-nums;
}

.controls-sep {
  width: 1px;
  height: 16px;
  background: var(--ui-border);
  margin: 0 2px;
  flex-shrink: 0;
}

#theme-toggle {
  font-size: 15px;
  padding: 3px 9px;
}

/* ── Strip viewport ──────────────────────────────────────── */

#strip-viewport {
  flex: 1;
  overflow-x: auto;
  overflow-y: hidden;
  display: flex;
  align-items: center;
  cursor: ew-resize;
  position: relative;
  scrollbar-width: thin;
  scrollbar-color: var(--tile-border) transparent;
}

#strip-viewport::-webkit-scrollbar {
  height: 3px;
}
#strip-viewport::-webkit-scrollbar-track {
  background: transparent;
}
#strip-viewport::-webkit-scrollbar-thumb {
  background: var(--tile-border);
  border-radius: 2px;
}

#strip-track {
  display: flex;
  flex-direction: row;
  align-items: center;
  flex-shrink: 0;
  min-width: max-content;
  gap: var(--tile-gap);
  /* padding-left/right set by JS */
}

/* ── Tiles ───────────────────────────────────────────────── */

.tile {
  width: var(--tile-size);
  height: var(--tile-size);
  flex-shrink: 0;
  border: 1px solid var(--tile-border);
  background: var(--tile-bg);
  color: var(--tile-fg);
  font-family: var(--font-mono);
  font-size: var(--tile-font-size);
  font-weight: 700;
  display: flex;
  align-items: center;
  justify-content: center;
  position: relative;
  user-select: none;
  transition: background 0.4s, color 0.4s, border-color 0.4s, box-shadow 0.4s;
}

.tile[data-state="one"] {
  color: var(--one-fg);
  font-style: italic;
  font-weight: 400;
}

.tile[data-state="prime"] {
  background: var(--prime-bg);
  color: var(--prime-fg);
  border-color: var(--prime-fg);
  font-weight: 700;
  box-shadow:
    0 0 10px var(--prime-glow),
    0 0 24px var(--prime-glow2),
    inset 0 0 8px var(--prime-glow2);
  animation: prime-emerge 0.55s cubic-bezier(0.34, 1.56, 0.64, 1) forwards;
}

.tile[data-state="composite"] {
  background: var(--composite-bg);
  color: var(--composite-fg);
  border-color: var(--tile-border);
  opacity: 0.65;
  text-decoration: line-through;
  text-decoration-color: var(--composite-fg);
}

.tile[data-state="wave-hit"] {
  animation: wave-flash 0.28s ease-out forwards;
}

/* ── Keyframes ───────────────────────────────────────────── */

@keyframes prime-emerge {
  0%   { transform: scale(0.86); opacity: 0.7; }
  55%  { transform: scale(1.11); }
  100% { transform: scale(1);    opacity: 1;   }
}

@keyframes wave-flash {
  0% {
    border-color: var(--wave-color);
    box-shadow: 0 0 8px var(--wave-color);
  }
  100% {
    border-color: var(--tile-border);
    box-shadow: none;
    background: var(--composite-bg);
    color: var(--composite-fg);
    opacity: 0.65;
  }
}


@keyframes hint-bob {
  0%, 100% { transform: translateY(0); opacity: 0.6; }
  50%       { transform: translateY(7px); opacity: 1; }
}

/* ── Canvas + Lens ───────────────────────────────────────── */

#wave-canvas {
  position: fixed;
  top: 0;
  left: 0;
  pointer-events: none;
  z-index: 10;
  /* physical size set by JS */
}

#center-lens {
  position: fixed;
  left: 50vw;
  top: var(--header-h);
  bottom: 0;
  width: 2px;
  transform: translateX(-50%);
  background: linear-gradient(
    to bottom,
    transparent 0%,
    var(--lens-color) 15%,
    var(--lens-color) 85%,
    transparent 100%
  );
  pointer-events: none;
  z-index: 20;
  opacity: 0;
}


/* ── Scroll hint ─────────────────────────────────────────── */

#scroll-hint {
  position: fixed;
  bottom: 20px;
  right: 28px;
  font-family: var(--font-mono);
  font-size: 10px;
  letter-spacing: 0.1em;
  color: var(--ui-fg);
  pointer-events: none;
  z-index: 30;
  transition: opacity 0.7s ease;
  animation: hint-bob 2.2s ease-in-out infinite;
}

/* ── Compact zoom (labels hidden below 75%) ─────────────── */

body.zoom-compact .tile {
  color: transparent !important;
  text-decoration-color: transparent !important;
  transition: background 0.4s, color 0.25s, border-color 0.4s, box-shadow 0.4s, opacity 0.4s;
}

body.zoom-compact .tile[data-state="prime"] {
  background: var(--wave-color) !important;
  border-color: var(--wave-color) !important;
}

/* ── Reduced motion ──────────────────────────────────────── */

@media (prefers-reduced-motion: reduce) {
  .tile                  { animation: none !important; transition: background 0.15s, color 0.15s, opacity 0.15s; }
  #center-lens           { animation: none !important; }
  #scroll-hint           { animation: none; }
}