/* ============================================
   VISUALIZATIONS — Animated bars, sort demos,
   trees, racing bars, sparklines
   ============================================ */

/* === Shared button === */
.viz-btn {
  padding: 6px 14px;
  border: 1px solid var(--accent-border);
  border-radius: var(--radius-sm);
  background: var(--bg-surface);
  color: var(--accent);
  font-family: 'Rubik', sans-serif;
  font-size: 0.75rem;
  cursor: pointer;
  transition: background 0.2s, color 0.2s;
}
.viz-btn:hover {
  background: var(--accent);
  color: var(--text-on-accent);
}
.viz-btn:disabled {
  opacity: 0.4;
  cursor: not-allowed;
}

.viz-stage {
  width: 100%;
  will-change: transform, opacity;
  position: relative;
  z-index: 1;
}

.viz-stage-wrap {
  position: relative;
  isolation: isolate;
  overflow: clip;
  transition: min-height var(--motion-viz-minheight-duration) var(--motion-viz-minheight-easing);
}

.viz-controls {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  justify-content: center;
  gap: 8px;
  margin-top: 8px;
}

.viz-controls__status {
  font-family: 'JetBrains Mono', monospace;
  font-size: 0.62rem;
  color: var(--text-muted);
  min-width: 92px;
  text-align: center;
}

.viz-inline-meta {
  margin-top: 6px;
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 10px;
  flex-wrap: wrap;
  color: var(--text-muted);
  font-size: 0.7rem;
}

.viz-legend {
  display: flex;
  gap: 14px;
  justify-content: center;
  margin-top: 8px;
  font-size: 0.68rem;
}

.viz-message {
  margin-top: 8px;
  text-align: center;
  color: var(--text-muted);
  font-size: 0.72rem;
}

.viz-message--ok {
  color: var(--success);
  font-weight: 600;
}

@media (prefers-reduced-motion: reduce) {
  .viz-stage,
  .viz-stage-wrap {
    transition: none !important;
  }
}

/* === Big-O growth (slide 4) === */
.viz-growth {
  max-width: 640px;
  margin: 0 auto;
}

.viz-growth__top {
  display: grid;
  grid-template-columns: 1fr 220px;
  gap: 12px;
  align-items: start;
}

.viz-growth__chart {
  width: 100%;
  background: var(--bg-code);
  border-radius: 10px;
  padding: 8px;
}

.viz-axis {
  stroke: var(--text-muted);
  stroke-width: 1;
}

.viz-axis__label {
  fill: var(--text-muted);
  font-size: 9px;
  font-family: 'Rubik', sans-serif;
}

.viz-line {
  fill: none;
  stroke-width: 2.2;
  opacity: 0.25;
  stroke-dasharray: 420;
  stroke-dashoffset: 420;
  transition: stroke-dashoffset var(--motion-viz-line-duration) var(--motion-viz-line-easing), opacity 0.25s ease;
}

.viz-line--on {
  opacity: 1;
  stroke-dashoffset: 0;
}

.viz-growth__table {
  background: var(--bg-surface-2);
  border: 1px solid var(--border);
  border-radius: 8px;
  padding: 8px;
}

.viz-growth__table-title {
  color: var(--text-secondary);
  font-size: 0.68rem;
  margin-bottom: 6px;
}

.viz-growth__row {
  display: grid;
  grid-template-columns: 10px 1fr auto;
  gap: 6px;
  align-items: center;
  font-size: 0.66rem;
  color: var(--text-secondary);
  margin-bottom: 4px;
}

.viz-growth__dot {
  width: 8px;
  height: 8px;
  border-radius: 999px;
}

.viz-growth__slider-wrap {
  margin-top: 8px;
  display: flex;
  align-items: center;
  gap: 10px;
  font-size: 0.68rem;
  color: var(--text-secondary);
}

.viz-growth__slider {
  flex: 1;
}

/* === 1. Animated Bars (O(n) vs O(n²)) === */
.viz-bars { max-width: 500px; margin: 0 auto; }
.viz-bars__row { margin-bottom: 8px; }
.viz-bars__row--visible { opacity: 1; }
.viz-bars__label {
  display: block;
  font-family: 'JetBrains Mono', monospace;
  font-size: 0.7rem;
  color: var(--text-muted);
  margin-bottom: 2px;
}
.viz-bars__pair { display: flex; flex-direction: column; gap: 3px; }
.viz-bars__track {
  height: 22px;
  background: var(--bg-surface-2);
  border-radius: 4px;
  overflow: hidden;
  position: relative;
}
.viz-bars__bar {
  height: 100%;
  border-radius: 4px;
  display: flex;
  align-items: center;
  padding: 0 8px;
  font-family: 'JetBrains Mono', monospace;
  font-size: 0.6rem;
  color: #fff;
  width: 0;
  transition: none;
  min-width: fit-content;
}
.viz-bars__bar--on { background: #3B82F6; }
.viz-bars__bar--on2 { background: #FB7185; }
.viz-bars__bar--animate {
  width: var(--target-w) !important;
  transition: width var(--motion-viz-bars-duration) var(--motion-viz-bars-easing);
}

/* === Binary search (slide 10) === */
.viz-binary {
  max-width: 560px;
  margin: 0 auto;
}

.viz-binary__arr {
  display: flex;
  flex-wrap: wrap;
  justify-content: center;
  gap: 4px;
}

.viz-binary__cell {
  min-width: 44px;
  padding: 6px 4px;
  border: 1px solid var(--border);
  border-radius: 6px;
  background: var(--bg-surface-2);
  color: var(--text-secondary);
  text-align: center;
  font-family: 'JetBrains Mono', monospace;
  font-size: 0.74rem;
  transition: all 0.25s ease;
}

.viz-binary__cell--faded {
  opacity: 0.18;
}

.viz-binary__cell--mid {
  border-color: #f59e0b;
  background: rgba(245, 158, 11, 0.18);
  color: #f59e0b;
}

.viz-binary__cell--found {
  border-color: #22c55e;
  background: rgba(34, 197, 94, 0.2);
  color: #22c55e;
}

.viz-binary__idx {
  display: block;
  font-size: 0.55rem;
  color: var(--text-muted);
  margin-bottom: 1px;
}

.viz-binary__meta {
  margin-top: 6px;
  display: flex;
  justify-content: center;
  gap: 8px;
  flex-wrap: wrap;
  font-size: 0.66rem;
  color: var(--text-muted);
  font-family: 'JetBrains Mono', monospace;
}

.viz-binary__hint {
  margin-top: 5px;
  text-align: center;
  color: var(--text-muted);
  font-size: 0.64rem;
}

/* === 2. Selection Sort / QuickSort Bars === */
.viz-sort__bars {
  display: flex;
  align-items: flex-end;
  justify-content: center;
  gap: 4px;
  height: 120px;
  padding: 0 8px;
}
.viz-sort__bar {
  flex: 1;
  max-width: 44px;
  background: var(--bg-surface-2);
  border: 1px solid var(--border);
  border-radius: 4px 4px 0 0;
  display: flex;
  align-items: flex-start;
  justify-content: center;
  padding-top: 4px;
  transition: background 0.3s, border-color 0.3s;
  position: relative;
}
.viz-sort__bar span {
  font-family: 'JetBrains Mono', monospace;
  font-size: 0.65rem;
  color: var(--text-secondary);
}
.viz-sort__bar--sorted {
  background: rgba(52, 211, 153, 0.15);
  border-color: var(--accent);
}
.viz-sort__bar--sorted span { color: var(--accent); }
.viz-sort__bar--min {
  background: rgba(251, 113, 133, 0.2);
  border-color: #FB7185;
}
.viz-sort__bar--min span { color: #FB7185; }
.viz-sort__bar--scan {
  background: rgba(34, 211, 238, 0.15);
  border-color: #22D3EE;
}
.viz-sort__bar--scan span { color: #22D3EE; }
.viz-sort__bar--pivot {
  background: rgba(52, 211, 153, 0.25);
  border-color: var(--accent);
  border-width: 2px;
}
.viz-sort__bar--pivot span { color: var(--accent); font-weight: 600; }

/* === Memory model (slide 12) === */
.viz-memory {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 10px;
}

.viz-memory__side {
  background: var(--bg-surface-2);
  border: 1px solid var(--border);
  border-radius: 8px;
  padding: 8px;
}

.viz-memory__side h4 {
  margin: 0 0 6px;
  font-size: 0.76rem;
  color: var(--text-secondary);
}

.viz-memory__row {
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 4px;
  flex-wrap: wrap;
}

.viz-memory__row--links span {
  color: var(--text-muted);
}

.viz-memory__cell {
  padding: 5px 8px;
  min-width: 30px;
  text-align: center;
  border-radius: 6px;
  border: 1px solid var(--border);
  background: var(--bg-code);
  color: var(--text-secondary);
  font-family: 'JetBrains Mono', monospace;
  font-size: 0.7rem;
  transition: all 0.2s ease;
}

.viz-memory__cell--active {
  border-color: #22d3ee;
  background: rgba(34, 211, 238, 0.14);
  color: #22d3ee;
}

.viz-memory__cell--insert {
  border-color: var(--accent);
  background: var(--accent-light);
  color: var(--accent);
  font-weight: 600;
}

.viz-memory__hint {
  margin-top: 6px;
  font-size: 0.63rem;
  color: var(--text-muted);
  text-align: center;
}

/* === Recursion stack (slide 15) === */
.viz-stack {
  display: flex;
  flex-direction: column;
  gap: 4px;
  max-width: 280px;
  margin: 0 auto;
}

.viz-stack__frame {
  border: 1px solid var(--border);
  border-radius: 6px;
  padding: 4px 8px;
  background: var(--bg-surface-2);
  color: var(--text-secondary);
  font-family: 'JetBrains Mono', monospace;
  font-size: 0.64rem;
  text-align: center;
}

.viz-stack__frame--active {
  border-color: var(--accent);
  background: var(--accent-light);
  color: var(--accent);
  font-weight: 600;
}

/* === 5. Racing Bars === */
.viz-race { max-width: 500px; margin: 0 auto; }
.viz-race__row {
  display: flex;
  align-items: center;
  gap: 8px;
  margin-bottom: 6px;
}
.viz-race__algo {
  font-family: 'JetBrains Mono', monospace;
  font-size: 0.65rem;
  width: 130px;
  flex-shrink: 0;
  text-align: right;
}
.viz-race__track {
  flex: 1;
  height: 24px;
  background: var(--bg-surface-2);
  border-radius: 4px;
  overflow: hidden;
}
.viz-race__bar {
  height: 100%;
  border-radius: 4px;
  width: 0;
  transition: none;
}
.viz-race__bar--bubble { background: #FB7185; }
.viz-race__bar--sorted { background: #84CC16; }
.viz-race__bar--animate {
  width: var(--target-w) !important;
  transition: width var(--motion-viz-race-duration) var(--motion-viz-race-easing);
}
.viz-race__val {
  font-family: 'JetBrains Mono', monospace;
  font-size: 0.6rem;
  width: 100px;
  flex-shrink: 0;
}

.viz-race__title {
  text-align: center;
  color: var(--text-secondary);
  font-size: 0.68rem;
  margin-bottom: 6px;
}

.viz-race__ratio {
  text-align: center;
  margin-top: 6px;
  font-size: 0.74rem;
  color: var(--error);
  font-weight: 600;
}

/* === 6. Horizontal Bars (sort comparison) === */
.viz-hbars { max-width: 450px; margin: 0 auto; }
.viz-hbars__row {
  display: flex;
  align-items: center;
  gap: 6px;
  margin-bottom: 4px;
}
.viz-hbars__name {
  font-family: 'JetBrains Mono', monospace;
  font-size: 0.65rem;
  color: var(--text-secondary);
  width: 110px;
  flex-shrink: 0;
  text-align: right;
}
.viz-hbars__track {
  flex: 1;
  height: 16px;
  background: var(--bg-surface-2);
  border-radius: 3px;
  overflow: hidden;
}
.viz-hbars__bar {
  height: 100%;
  border-radius: 3px;
  transition: width 0.8s ease;
}
.viz-hbars__val {
  font-family: 'JetBrains Mono', monospace;
  font-size: 0.6rem;
  color: var(--text-muted);
  width: 40px;
  flex-shrink: 0;
}

/* === 7. Two Sum Demo === */
.viz-twosum { text-align: center; }
.viz-twosum__arr {
  display: flex;
  justify-content: center;
  gap: 4px;
  margin-bottom: 8px;
}
.viz-twosum__cell {
  width: 50px;
  padding: 8px 0;
  background: var(--bg-surface-2);
  border: 1px solid var(--border);
  border-radius: 6px;
  font-family: 'JetBrains Mono', monospace;
  font-size: 0.85rem;
  color: var(--text-secondary);
  transition: all 0.3s;
}
.viz-twosum__cell--current {
  background: rgba(34, 211, 238, 0.15);
  border-color: #22D3EE;
  color: #22D3EE;
}
.viz-twosum__cell--found {
  background: rgba(52, 211, 153, 0.2);
  border-color: var(--accent);
  color: var(--accent);
}
.viz-twosum__idx {
  display: block;
  font-size: 0.55rem;
  color: var(--text-muted);
  margin-bottom: 2px;
}
.viz-twosum__dict {
  padding: 8px;
  background: var(--bg-code);
  border-radius: 6px;
  font-family: 'JetBrains Mono', monospace;
}

.viz-twosum__meta {
  text-align: center;
  font-size: 0.68rem;
  color: var(--text-muted);
  margin: 4px 0;
}

/* === Hash flow (slide 21) === */
.viz-hash {
  max-width: 560px;
  margin: 0 auto;
}

.viz-hash__keys {
  display: flex;
  justify-content: center;
  gap: 6px;
  flex-wrap: wrap;
}

.viz-hash__key {
  padding: 4px 8px;
  border: 1px solid var(--border);
  border-radius: 6px;
  background: var(--bg-surface-2);
  color: var(--text-secondary);
  font-family: 'JetBrains Mono', monospace;
  font-size: 0.66rem;
  transition: border-color 0.25s ease, background 0.25s ease, color 0.25s ease, transform 0.25s ease;
}

.viz-hash__key--active {
  border-color: var(--accent);
  background: var(--accent-light);
  color: var(--accent);
  transform: translateY(-2px);
}

.viz-hash__pipe {
  margin: 8px 0;
  display: flex;
  justify-content: center;
  align-items: center;
  gap: 6px;
  flex-wrap: wrap;
}

.viz-hash__arrow {
  color: var(--text-muted);
  font-size: 0.8rem;
}

.viz-hash__func,
.viz-hash__slot {
  padding: 5px 10px;
  border-radius: 6px;
  border: 1px solid var(--border);
  background: var(--bg-code);
  color: var(--text-secondary);
  font-family: 'JetBrains Mono', monospace;
  font-size: 0.65rem;
}

.viz-hash__slots {
  display: grid;
  gap: 4px;
  max-width: 220px;
  margin: 0 auto;
}

.viz-hash__slot-row {
  display: grid;
  grid-template-columns: 40px 1fr;
  gap: 8px;
  align-items: center;
  border: 1px solid var(--border);
  border-radius: 6px;
  padding: 3px 8px;
  background: var(--bg-surface-2);
  font-family: 'JetBrains Mono', monospace;
  font-size: 0.64rem;
  color: var(--text-secondary);
  transition: border-color 0.25s ease, background 0.25s ease, color 0.25s ease, transform 0.25s ease;
}

.viz-hash__slot-row--active {
  border-color: #22d3ee;
  background: rgba(34, 211, 238, 0.1);
  color: #22d3ee;
  transform: translateX(3px);
}

/* === BFS queue (slide 30) === */
.viz-graph-wave {
  max-width: 480px;
  margin: 0 auto;
}

.viz-queue {
  margin-top: 6px;
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 8px;
  flex-wrap: wrap;
  font-size: 0.66rem;
  color: var(--text-secondary);
}

.viz-queue__items {
  display: flex;
  gap: 4px;
  flex-wrap: wrap;
}

.viz-queue__item,
.viz-queue__empty {
  padding: 3px 8px;
  border-radius: 6px;
  border: 1px solid var(--border);
  background: var(--bg-surface-2);
  font-family: 'JetBrains Mono', monospace;
  font-size: 0.62rem;
}

.viz-queue__item {
  animation: queueItemPop var(--motion-viz-queue-pop-duration) var(--motion-viz-queue-pop-easing);
}

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

@keyframes queueItemPop {
  from {
    opacity: 0;
    transform: translateY(4px) scale(0.95);
  }
  to {
    opacity: 1;
    transform: translateY(0) scale(1);
  }
}

/* === Dijkstra (slide 35) === */
.viz-dijkstra {
  max-width: 560px;
  margin: 0 auto;
}

/* === Responsive === */
@media (max-width: 768px) {
  .viz-growth__top { grid-template-columns: 1fr; }
  .viz-memory { grid-template-columns: 1fr; }
  .viz-sort__bars { height: 90px; }
  .viz-bars__bar span { font-size: 0.5rem; }
  .viz-race__algo { width: 90px; font-size: 0.55rem; }
  .viz-race__val { width: 70px; font-size: 0.5rem; }
  .viz-hbars__name { width: 80px; font-size: 0.55rem; }
  .viz-twosum__cell { width: 40px; font-size: 0.75rem; }
}