/* ===== RECURSION TREE VISUALIZER ===== */
:root {
  --rtv-primary: #8b5cf6;
  --rtv-secondary: #a78bfa;
  --rtv-gradient: linear-gradient(135deg, #6d28d9 0%, #a78bfa 100%);
  --rtv-bg: rgba(139, 92, 246, 0.08);
  --rtv-bg-hover: rgba(139, 92, 246, 0.15);
  --rtv-pending: #f59e0b;
  --rtv-computing: #3b82f6;
  --rtv-computed: #10b981;
  --rtv-return: #a78bfa;
  --rtv-node-width: 130px;
  --rtv-node-height: 60px;
  --rtv-level-height: 110px;
}

.typing-text_rtv {
  color: var(--rtv-secondary);
  font-weight: 600;
}

.visualizer-container.rtv-layout {
  grid-template-columns: 280px 1fr 280px;
  gap: 1rem;
}

.rtv-tree-canvas {
  position: relative;
  min-height: 460px;
  background: rgba(10, 10, 26, 0.45);
  border: 1px solid var(--glass-border);
  border-radius: 12px;
  overflow-x: auto;
  overflow-y: hidden;
}

.rtv-tree-canvas svg {
  position: absolute;
  top: 0;
  left: 0;
  width: 100%;
  height: 100%;
  pointer-events: none;
  z-index: 1;
}

.rtv-tree-inner {
  position: relative;
  width: 100%;
  height: 100%;
  min-height: 460px;
  z-index: 2;
}

.rtv-tree-placeholder {
  position: absolute;
  top: 50%;
  left: 50%;
  transform: translate(-50%, -50%);
  color: var(--text-secondary);
  font-size: 1.1rem;
  font-weight: 500;
  opacity: 0.7;
  text-align: center;
  pointer-events: none;
}

.rtv-tree-placeholder i {
  display: block;
  font-size: 2.5rem;
  margin-bottom: 0.75rem;
  opacity: 0.5;
}

/* ── Recursion Node ── */
.rtv-node {
  position: absolute;
  width: var(--rtv-node-width);
  min-height: var(--rtv-node-height);
  background: var(--glass-bg);
  border: 2px solid var(--glass-border);
  border-radius: 10px;
  padding: 6px 10px;
  cursor: pointer;
  transition: border-color 0.3s ease, box-shadow 0.3s ease, opacity 0.3s ease;
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  user-select: none;
  transform: translate(-50%, -50%);
  z-index: 5;
  overflow: visible;
  box-sizing: border-box;
}

.rtv-node:hover {
  z-index: 10;
}

.rtv-node .rtv-fn-name {
  font-family: "Fira Code", monospace;
  font-size: 0.72rem;
  font-weight: 600;
  color: var(--text-secondary);
  line-height: 1.3;
  max-width: 100%;
  overflow: visible;
  text-overflow: unset;
  white-space: nowrap;
}

.rtv-node .rtv-fn-name .rtv-args {
  color: var(--text-primary);
}

.rtv-node .rtv-return-val {
  font-family: "Fira Code", monospace;
  font-size: 0.78rem;
  font-weight: 700;
  color: var(--rtv-return);
  margin-top: 2px;
  display: none;
  max-width: 100%;
  overflow: visible;
  text-overflow: unset;
  white-space: nowrap;
}

.rtv-node .rtv-return-val.visible {
  display: block;
  animation: rtv-pop-in 0.3s ease;
}

.rtv-node .rtv-collapse-btn {
  position: absolute;
  top: -8px;
  right: -8px;
  width: 18px;
  height: 18px;
  border-radius: 50%;
  background: var(--rtv-primary);
  border: 2px solid var(--bg-primary);
  color: white;
  font-size: 0.65rem;
  font-weight: 700;
  display: flex;
  align-items: center;
  justify-content: center;
  cursor: pointer;
  opacity: 0;
  transition: opacity 0.2s ease;
  line-height: 1;
}

.rtv-node:hover .rtv-collapse-btn {
  opacity: 1;
}

.rtv-node .rtv-partial-label {
  font-size: 0.65rem;
  color: var(--text-secondary);
  opacity: 0.7;
  margin-top: 1px;
}

/* Node States */
.rtv-node.state-pending {
  border-color: var(--rtv-pending);
  box-shadow: 0 0 8px rgba(245, 158, 11, 0.2);
}

.rtv-node.state-computing {
  border-color: var(--rtv-computing);
  box-shadow: 0 0 16px rgba(59, 130, 246, 0.4);
  animation: rtv-pulse-blue 1.2s ease-in-out infinite;
}

.rtv-node.state-computed {
  border-color: var(--rtv-computed);
  box-shadow: 0 0 8px rgba(16, 185, 129, 0.25);
}

.rtv-node.state-computed .rtv-fn-name {
  color: var(--rtv-computed);
}

.rtv-node.state-computed .rtv-args {
  color: var(--text-primary);
}

/* Nodes hidden when parent collapsed */
.rtv-node.node-collapsed {
  opacity: 0;
  pointer-events: none;
}

/* SVG Edges */
.rtv-edge {
  stroke: var(--glass-border);
  stroke-width: 2;
  fill: none;
  transition: stroke 0.3s ease, opacity 0.3s ease;
}

.rtv-edge.edge-pending {
  stroke: var(--rtv-pending);
  stroke-dasharray: 4 4;
  opacity: 0.5;
}

.rtv-edge.edge-active {
  stroke: var(--rtv-computing);
  stroke-width: 2.5;
  opacity: 1;
}

.rtv-edge.edge-computed {
  stroke: var(--rtv-computed);
  opacity: 0.8;
}

.rtv-edge.edge-hidden {
  opacity: 0;
}

/* Edge return-value animation */
.rtv-edge-return-flow {
  stroke: var(--rtv-return);
  stroke-width: 3;
  stroke-dasharray: 6 6;
  animation: rtv-flow 0.6s linear infinite;
  opacity: 0;
  transition: opacity 0.3s ease;
}

.rtv-edge-return-flow.visible {
  opacity: 1;
}

/* ── Stack Panel ── */
.rtv-info-panel {
  background: var(--glass-bg);
  border: 1px solid var(--glass-border);
  border-radius: 12px;
  padding: 1rem;
  backdrop-filter: blur(10px);
}

.rtv-panel-title {
  font-size: 0.75rem;
  font-weight: 600;
  text-transform: uppercase;
  letter-spacing: 0.08em;
  color: var(--text-secondary);
  margin-bottom: 0.75rem;
  display: flex;
  align-items: center;
  gap: 0.5rem;
}

.rtv-panel-title i {
  color: var(--rtv-primary);
}

.rtv-stack-container {
  max-height: 300px;
  overflow-y: auto;
  display: flex;
  flex-direction: column;
  gap: 2px;
}

.rtv-stack-frame {
  display: flex;
  align-items: center;
  gap: 0.5rem;
  padding: 0.45rem 0.65rem;
  background: rgba(255, 255, 255, 0.03);
  border: 1px solid var(--glass-border);
  border-radius: 6px;
  font-family: "Fira Code", monospace;
  font-size: 0.78rem;
  color: var(--text-secondary);
  transition: all 0.3s ease;
  position: relative;
}

.rtv-stack-frame .rtv-stack-idx {
  font-size: 0.65rem;
  color: var(--text-secondary);
  opacity: 0.5;
  width: 16px;
  text-align: right;
}

.rtv-stack-frame .rtv-stack-ret {
  margin-left: auto;
  font-size: 0.7rem;
  color: var(--rtv-return);
  font-weight: 600;
}

.rtv-stack-frame.active {
  background: rgba(59, 130, 246, 0.1);
  border-color: var(--rtv-computing);
  color: var(--text-primary);
  box-shadow: 0 0 8px rgba(59, 130, 246, 0.15);
}

.rtv-stack-frame.done {
  background: rgba(16, 185, 129, 0.08);
  border-color: var(--rtv-computed);
  color: var(--text-secondary);
}

.rtv-stack-frame.entering {
  animation: rtv-slide-in 0.25s ease;
}

@keyframes rtv-slide-in {
  from {
    transform: translateX(-10px);
    opacity: 0;
  }
  to {
    transform: translateX(0);
    opacity: 1;
  }
}

/* ── Return Values Panel ── */
.rtv-returns-container {
  max-height: 200px;
  overflow-y: auto;
  display: flex;
  flex-direction: column;
  gap: 0.25rem;
}

.rtv-return-item {
  display: flex;
  align-items: center;
  gap: 0.5rem;
  padding: 0.3rem 0.5rem;
  font-family: "Fira Code", monospace;
  font-size: 0.75rem;
  color: var(--text-secondary);
  border-radius: 4px;
  animation: rtv-pop-in 0.3s ease;
}

.rtv-return-item .rtv-ret-fn {
  color: var(--text-primary);
  font-weight: 500;
}

.rtv-return-item .rtv-ret-arrow {
  color: var(--rtv-return);
  font-weight: 700;
  margin: 0 0.25rem;
}

.rtv-return-item .rtv-ret-value {
  color: var(--rtv-return);
  font-weight: 700;
}

/* ── Execution Log ── */
.rtv-log-container {
  max-height: 140px;
  overflow-y: auto;
  font-family: "Fira Code", monospace;
  font-size: 0.72rem;
  line-height: 1.6;
}

.rtv-log-container::-webkit-scrollbar,
.rtv-stack-container::-webkit-scrollbar,
.rtv-returns-container::-webkit-scrollbar {
  width: 4px;
}

.rtv-log-container::-webkit-scrollbar-thumb,
.rtv-stack-container::-webkit-scrollbar-thumb,
.rtv-returns-container::-webkit-scrollbar-thumb {
  background: var(--glass-border);
  border-radius: 2px;
}

.rtv-log-line {
  padding: 0.15rem 0.3rem;
  border-radius: 2px;
  white-space: nowrap;
  animation: rtv-fade-in 0.2s ease;
}

.rtv-log-line .rtv-log-time {
  color: var(--text-secondary);
  opacity: 0.5;
  margin-right: 0.5rem;
}

.rtv-log-line .rtv-log-call {
  color: var(--rtv-computing);
}

.rtv-log-line .rtv-log-return {
  color: var(--rtv-computed);
}

.rtv-log-line .rtv-log-info {
  color: var(--text-secondary);
}

/* ── Legend ── */
.rtv-legend {
  display: flex;
  gap: 1rem;
  padding: 0.5rem 0;
  flex-wrap: wrap;
}

.rtv-legend-item {
  display: flex;
  align-items: center;
  gap: 0.4rem;
  font-size: 0.75rem;
  color: var(--text-secondary);
}

.rtv-legend-dot {
  width: 10px;
  height: 10px;
  border-radius: 50%;
  flex-shrink: 0;
}

.rtv-legend-dot.dot-pending { background: var(--rtv-pending); }
.rtv-legend-dot.dot-computing { background: var(--rtv-computing); }
.rtv-legend-dot.dot-computed { background: var(--rtv-computed); }
.rtv-legend-dot.dot-return { background: var(--rtv-return); }

/* ── Information Box ── */
.rtv-algo-info {
  font-size: 0.8rem;
  color: var(--text-secondary);
  line-height: 1.6;
}

.rtv-algo-info code {
  font-family: "Fira Code", monospace;
  font-size: 0.78rem;
  color: var(--rtv-secondary);
  background: rgba(139, 92, 246, 0.1);
  padding: 0.1rem 0.3rem;
  border-radius: 3px;
}

.rtv-stats-grid {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 0.5rem;
  margin-top: 0.5rem;
}

.rtv-stat {
  background: rgba(255, 255, 255, 0.02);
  border: 1px solid var(--glass-border);
  border-radius: 6px;
  padding: 0.4rem 0.6rem;
}

.rtv-stat-label {
  font-size: 0.65rem;
  color: var(--text-secondary);
  text-transform: uppercase;
  letter-spacing: 0.05em;
}

.rtv-stat-value {
  font-family: "Fira Code", monospace;
  font-size: 0.9rem;
  font-weight: 600;
  color: var(--rtv-primary);
  margin-top: 0.15rem;
}

/* ── Zoom Controls ── */
.rtv-zoom-controls {
  display: flex;
  gap: 0.25rem;
  margin-top: 0.5rem;
}

.rtv-zoom-btn {
  width: 28px;
  height: 28px;
  display: flex;
  align-items: center;
  justify-content: center;
  background: rgba(255, 255, 255, 0.05);
  border: 1px solid var(--glass-border);
  border-radius: 6px;
  color: var(--text-secondary);
  cursor: pointer;
  font-size: 0.75rem;
  transition: all 0.2s ease;
}

.rtv-zoom-btn:hover {
  background: var(--rtv-bg);
  border-color: var(--rtv-primary);
  color: var(--text-primary);
}

/* ── Animations ── */
@keyframes rtv-pulse-blue {
  0%, 100% { box-shadow: 0 0 8px rgba(59, 130, 246, 0.3); }
  50% { box-shadow: 0 0 20px rgba(59, 130, 246, 0.6); }
}

@keyframes rtv-pop-in {
  0% { transform: scale(0.8); opacity: 0; }
  50% { transform: scale(1.05); }
  100% { transform: scale(1); opacity: 1; }
}

@keyframes rtv-fade-in {
  from { opacity: 0; }
  to { opacity: 1; }
}

@keyframes rtv-flow {
  0% { stroke-dashoffset: 12; }
  100% { stroke-dashoffset: 0; }
}

@keyframes rtv-glow-in {
  0% { box-shadow: 0 0 0 rgba(139, 92, 246, 0); }
  100% { box-shadow: 0 0 20px rgba(139, 92, 246, 0.4); }
}

/* ── Section Overrides ── */
.rtv-sidebar {
  display: flex;
  flex-direction: column;
  gap: 1rem;
}

/* ── Responsive ── */
@media (max-width: 1200px) {
  .visualizer-container.rtv-layout {
    grid-template-columns: 240px 1fr;
  }
  .rtv-info-panel.rtv-stack-panel {
    display: none;
  }
}

@media (max-width: 1024px) {
  .visualizer-container.rtv-layout {
    grid-template-columns: 1fr;
  }
  .rtv-tree-canvas {
    min-height: 360px;
  }
  .rtv-tree-inner {
    min-height: 360px;
  }
}

@media (max-width: 768px) {
  .rtv-node {
    min-height: 48px;
    padding: 4px 8px;
  }
  .rtv-node .rtv-fn-name {
    font-size: 0.65rem;
  }
  .rtv-node .rtv-return-val {
    font-size: 0.7rem;
  }
  .rtv-legend {
    gap: 0.6rem;
  }
}

@media (max-width: 480px) {
  .rtv-node {
    min-height: 40px;
    padding: 3px 6px;
  }
  .rtv-node .rtv-fn-name {
    font-size: 0.58rem;
  }
  .rtv-node .rtv-return-val {
    font-size: 0.6rem;
  }
  .rtv-stack-frame {
    font-size: 0.7rem;
    padding: 0.3rem 0.5rem;
  }
}

/* ── Shared Visualizer Styles (local copy) ── */
.status-box {
  background: var(--dark-surface);
  border: 1px solid var(--glass-border);
  border-radius: 8px;
  padding: 1rem;
  font-size: 0.85rem;
  color: var(--text-secondary);
  font-family: "Fira Code", monospace;
  overflow-wrap: break-word;
}

.visualizer-card {
  background: var(--glass-bg);
  border: 1px solid var(--glass-border);
  border-radius: 16px;
  padding: 1.5rem;
  backdrop-filter: blur(10px);
  box-shadow: var(--glass-shadow);
  position: relative;
  overflow: hidden;
}

.visualizer-card::before {
  content: "";
  position: absolute;
  top: 0;
  left: 0;
  width: 100%;
  height: 3px;
  background: var(--gradient-1);
}

.control-group {
  display: flex;
  flex-direction: column;
  gap: 0.5rem;
  margin-bottom: 1rem;
}

.control-group label {
  font-size: 0.85rem;
  font-weight: 600;
  color: var(--text-secondary);
  display: flex;
  justify-content: space-between;
}

.control-group label span.val-display {
  color: var(--accent);
  font-family: "Fira Code", monospace;
}

.control-input {
  background: rgba(255, 255, 255, 0.06);
  border: 1px solid var(--glass-border);
  border-radius: 8px;
  color: var(--text-primary);
  padding: 0.65rem 0.8rem;
  font-family: inherit;
  font-size: 0.9rem;
  outline: none;
  width: 100%;
  transition: all 0.2s;
}

.control-input:focus {
  border-color: var(--primary-light);
  box-shadow: 0 0 0 2px rgba(167, 139, 250, 0.2);
}

.btn-control-row {
  display: flex;
  gap: 0.5rem;
}

.btn-control {
  flex: 1;
  padding: 0.65rem 0.4rem;
  font-weight: 600;
  display: flex;
  justify-content: center;
  align-items: center;
  gap: 0.3rem;
  cursor: pointer;
  transition: all 0.2s ease;
  font-size: 0.78rem;
}

.btn-control:disabled {
  opacity: 0.5;
  cursor: not-allowed;
}

input[type="range"].slider-custom {
  -webkit-appearance: none;
  appearance: none;
  width: 100%;
  height: 6px;
  border-radius: 3px;
  background: rgba(255, 255, 255, 0.1);
  outline: none;
  transition: background 0.3s;
}

input[type="range"].slider-custom::-webkit-slider-thumb {
  -webkit-appearance: none;
  appearance: none;
  width: 16px;
  height: 16px;
  border-radius: 50%;
  background: var(--primary-light);
  cursor: pointer;
  transition: transform 0.1s ease;
  box-shadow: 0 0 6px rgba(124, 58, 237, 0.5);
}

input[type="range"].slider-custom::-webkit-slider-thumb:hover {
  transform: scale(1.2);
}

.visualizer-main-panel {
  display: flex;
  flex-direction: column;
  gap: 1.5rem;
}

.visualizer-sidebar {
  display: flex;
  flex-direction: column;
  gap: 1.5rem;
}

@media (max-width: 768px) {
  .btn-control-row {
    flex-wrap: wrap;
  }
  .btn-control {
    font-size: 0.72rem;
    padding: 0.5rem 0.3rem;
  }
}

@media (max-width: 480px) {
  .btn-control-row {
    flex-direction: column;
  }
}