:root {
  --bg-primary: #0b0f19;
  --bg-secondary: #121826;
  --bg-panel: rgba(18, 24, 38, 0.85);
  --bg-panel-subtle: rgba(25, 34, 53, 0.7);
  --border-color: rgba(255, 255, 255, 0.1);
  --border-highlight: rgba(99, 102, 241, 0.5);
  --text-primary: #f1f5f9;
  --text-secondary: #94a3b8;
  --text-muted: #64748b;
  --accent-primary: #6366f1;
  --accent-glow: rgba(99, 102, 241, 0.35);
  --accent-secondary: #06b6d4;
  --accent-pink: #ec4899;
  --accent-green: #10b981;
  --danger: #ef4444;
  --panel-radius: 12px;
  --transition-speed: 0.2s;
  --font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, Helvetica, Arial, sans-serif;
  --font-mono: ui-monospace, SFMono-Regular, Menlo, Monaco, Consolas, monospace;
}

* {
  box-sizing: border-box;
  margin: 0;
  padding: 0;
  -webkit-tap-highlight-color: transparent;
}

body {
  background-color: var(--bg-primary);
  color: var(--text-primary);
  font-family: var(--font-family);
  overflow: hidden;
  height: 100vh;
  width: 100vw;
  display: flex;
  user-select: none;
}

/* Simulation Canvas Container */
#sim-container {
  position: relative;
  flex: 1;
  height: 100%;
  display: flex;
  align-items: center;
  justify-content: center;
  background: radial-gradient(circle at center, #131a2d 0%, #080c14 100%);
  overflow: hidden;
}

#canvas {
  display: block;
  cursor: crosshair;
}

/* Top HUD Bar */
.hud-bar {
  position: absolute;
  top: 16px;
  left: 20px;
  right: 20px;
  display: flex;
  justify-content: space-between;
  align-items: center;
  pointer-events: none;
  z-index: 10;
}

.hud-group {
  display: flex;
  gap: 10px;
  pointer-events: auto;
}

.hud-stat-pill {
  background: var(--bg-panel);
  backdrop-filter: blur(12px);
  -webkit-backdrop-filter: blur(12px);
  border: 1px solid var(--border-color);
  border-radius: 20px;
  padding: 6px 14px;
  display: flex;
  align-items: center;
  gap: 8px;
  font-size: 13px;
  font-weight: 500;
  box-shadow: 0 4px 16px rgba(0, 0, 0, 0.4);
}

.hud-stat-pill .label {
  color: var(--text-secondary);
  text-transform: uppercase;
  font-size: 10px;
  letter-spacing: 0.05em;
  font-weight: 600;
}

.hud-stat-pill .value {
  color: var(--text-primary);
  font-family: var(--font-mono);
  font-weight: 700;
}

.hud-stat-pill.counter .value {
  color: #38bdf8;
  font-size: 15px;
}

.hud-stat-pill.limit-alert {
  border-color: rgba(239, 68, 68, 0.6);
  animation: pulse-border 1.5s infinite alternate;
}

@keyframes pulse-border {
  from { box-shadow: 0 0 5px rgba(239, 68, 68, 0.3); }
  to { box-shadow: 0 0 15px rgba(239, 68, 68, 0.8); }
}

/* Centered Stopwatch Timer */
.hud-center-timer {
  position: absolute;
  left: 50%;
  transform: translateX(-50%);
  top: 0;
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  background: rgba(13, 17, 23, 0.88);
  border: 1px solid rgba(56, 189, 248, 0.35);
  backdrop-filter: blur(14px);
  -webkit-backdrop-filter: blur(14px);
  padding: 4px 20px 5px 20px;
  border-radius: 20px;
  box-shadow: 0 4px 20px rgba(0, 0, 0, 0.45), 0 0 15px rgba(56, 189, 248, 0.15);
  pointer-events: auto;
  user-select: none;
  transition: all 0.3s cubic-bezier(0.4, 0, 0.2, 1);
  z-index: 15;
}

.hud-center-timer .timer-label {
  font-size: 8.5px;
  font-weight: 800;
  letter-spacing: 0.12em;
  color: var(--text-muted);
  line-height: 1;
  margin-bottom: 2px;
  text-transform: uppercase;
}

.hud-center-timer .timer-display {
  font-family: var(--font-mono);
  font-size: 20px;
  font-weight: 800;
  letter-spacing: 0.05em;
  color: #38bdf8;
  font-variant-numeric: tabular-nums;
  line-height: 1.1;
  text-shadow: 0 0 12px rgba(56, 189, 248, 0.4);
}

.hud-center-timer.frozen {
  border-color: #f59e0b;
  background: rgba(26, 19, 10, 0.94);
  box-shadow: 0 0 25px rgba(245, 158, 11, 0.45), 0 4px 20px rgba(0, 0, 0, 0.5);
  animation: timer-pulse 2s infinite ease-in-out;
}

.hud-center-timer.frozen .timer-label {
  color: #fbbf24;
}

.hud-center-timer.frozen .timer-display {
  color: #fbbf24;
  text-shadow: 0 0 16px rgba(251, 191, 36, 0.7);
}

@keyframes timer-pulse {
  0%, 100% { box-shadow: 0 0 20px rgba(245, 158, 11, 0.4); }
  50% { box-shadow: 0 0 32px rgba(245, 158, 11, 0.75); }
}

/* Action Button Pills in HUD */
.hud-btn {
  background: var(--bg-panel);
  backdrop-filter: blur(12px);
  -webkit-backdrop-filter: blur(12px);
  border: 1px solid var(--border-color);
  color: var(--text-primary);
  border-radius: 20px;
  padding: 6px 14px;
  font-size: 13px;
  font-weight: 600;
  cursor: pointer;
  display: flex;
  align-items: center;
  gap: 6px;
  transition: all var(--transition-speed);
  box-shadow: 0 4px 16px rgba(0, 0, 0, 0.4);
}

.hud-btn:hover {
  background: rgba(40, 52, 80, 0.9);
  border-color: var(--border-highlight);
  transform: translateY(-1px);
}

.hud-btn:active {
  transform: translateY(0);
}

.hud-btn.primary {
  background: var(--accent-primary);
  border-color: var(--accent-primary);
  color: #ffffff;
}

.hud-btn.primary:hover {
  background: #4f46e5;
  box-shadow: 0 0 16px var(--accent-glow);
}

/* Chart Floating Overlay */
.chart-panel {
  position: absolute;
  bottom: 20px;
  left: 20px;
  width: 340px;
  background: var(--bg-panel);
  backdrop-filter: blur(14px);
  -webkit-backdrop-filter: blur(14px);
  border: 1px solid var(--border-color);
  border-radius: var(--panel-radius);
  padding: 12px;
  box-shadow: 0 8px 30px rgba(0, 0, 0, 0.5);
  z-index: 10;
  transition: opacity 0.2s, transform 0.2s;
}

.chart-panel.collapsed {
  height: 38px;
  overflow: hidden;
}

.chart-panel.collapsed canvas,
.chart-panel.collapsed .chart-stats {
  display: none;
}

.chart-header {
  display: flex;
  justify-content: space-between;
  align-items: center;
  margin-bottom: 8px;
  cursor: pointer;
}

.chart-title {
  font-size: 11px;
  font-weight: 700;
  text-transform: uppercase;
  letter-spacing: 0.05em;
  color: var(--text-secondary);
  display: flex;
  align-items: center;
  gap: 6px;
}

.chart-toggle-btn {
  background: none;
  border: none;
  color: var(--text-secondary);
  cursor: pointer;
  font-size: 14px;
}

#chart-canvas {
  width: 100%;
  height: 165px;
  border-radius: 6px;
  background: rgba(10, 14, 23, 0.6);
  display: block;
}

.chart-stats {
  display: flex;
  justify-content: space-between;
  margin-top: 8px;
  font-size: 10px;
  color: var(--text-muted);
  font-family: var(--font-mono);
}

/* Sidebar Controls Drawer */
#controls-sidebar {
  width: 380px;
  height: 100%;
  background: var(--bg-secondary);
  border-left: 1px solid var(--border-color);
  display: flex;
  flex-direction: column;
  z-index: 20;
  transition: transform 0.3s cubic-bezier(0.16, 1, 0.3, 1), margin-right 0.3s cubic-bezier(0.16, 1, 0.3, 1);
  overflow: hidden;
}

#controls-sidebar.hidden {
  margin-right: -380px;
}

.sidebar-header {
  padding: 16px 20px;
  border-bottom: 1px solid var(--border-color);
  display: flex;
  justify-content: space-between;
  align-items: center;
  background: rgba(18, 24, 38, 0.95);
}

.sidebar-header h2 {
  font-size: 16px;
  font-weight: 700;
  letter-spacing: -0.01em;
  display: flex;
  align-items: center;
  gap: 8px;
}

.sidebar-header h2 span.badge {
  background: var(--accent-glow);
  color: #a5b4fc;
  font-size: 10px;
  padding: 2px 6px;
  border-radius: 4px;
  text-transform: uppercase;
}

.sidebar-close-btn {
  background: none;
  border: none;
  color: var(--text-secondary);
  cursor: pointer;
  padding: 4px;
  border-radius: 6px;
  display: flex;
  align-items: center;
  justify-content: center;
}

.sidebar-close-btn:hover {
  background: var(--border-color);
  color: var(--text-primary);
}

.sidebar-content {
  flex: 1;
  overflow-y: auto;
  padding: 16px 20px;
  scrollbar-width: thin;
  scrollbar-color: var(--text-muted) transparent;
}

.sidebar-content::-webkit-scrollbar {
  width: 6px;
}

.sidebar-content::-webkit-scrollbar-thumb {
  background: var(--text-muted);
  border-radius: 3px;
}

.sidebar-footer {
  padding: 14px 20px;
  border-top: 1px solid var(--border-color);
  background: rgba(18, 24, 38, 0.95);
  display: flex;
  gap: 10px;
}

/* Control Sections & Groups */
.control-section {
  margin-bottom: 22px;
}

.control-section-title {
  font-size: 11px;
  font-weight: 700;
  text-transform: uppercase;
  letter-spacing: 0.08em;
  color: var(--accent-secondary);
  margin-bottom: 12px;
  display: flex;
  align-items: center;
  gap: 6px;
}

.control-group {
  margin-bottom: 14px;
}

.control-label-row {
  display: flex;
  justify-content: space-between;
  align-items: center;
  margin-bottom: 6px;
}

.control-label {
  font-size: 13px;
  font-weight: 500;
  color: var(--text-primary);
  display: flex;
  align-items: center;
  gap: 6px;
}

.control-value {
  font-family: var(--font-mono);
  font-size: 12px;
  color: var(--accent-secondary);
  background: rgba(6, 182, 212, 0.1);
  padding: 2px 6px;
  border-radius: 4px;
}

.control-desc {
  font-size: 11px;
  color: var(--text-muted);
  margin-top: 3px;
  line-height: 1.35;
}

/* Form Inputs */
input[type="range"] {
  -webkit-appearance: none;
  appearance: none;
  width: 100%;
  height: 6px;
  border-radius: 3px;
  background: #1e293b;
  outline: none;
  cursor: pointer;
  transition: background var(--transition-speed);
}

input[type="range"]::-webkit-slider-thumb {
  -webkit-appearance: none;
  appearance: none;
  width: 16px;
  height: 16px;
  border-radius: 50%;
  background: #6366f1;
  box-shadow: 0 0 10px rgba(99, 102, 241, 0.5);
  cursor: pointer;
  transition: transform 0.1s, background-color 0.2s;
}

input[type="range"]::-webkit-slider-thumb:hover {
  transform: scale(1.2);
  background: #818cf8;
}

select {
  width: 100%;
  background: #1e293b;
  border: 1px solid var(--border-color);
  color: var(--text-primary);
  padding: 8px 12px;
  border-radius: 8px;
  font-size: 13px;
  outline: none;
  cursor: pointer;
  transition: border-color var(--transition-speed);
}

select:focus {
  border-color: var(--accent-primary);
}

.toggle-row {
  display: flex;
  justify-content: space-between;
  align-items: center;
  padding: 4px 0;
}

.switch {
  position: relative;
  display: inline-block;
  width: 38px;
  height: 22px;
}

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

.slider {
  position: absolute;
  cursor: pointer;
  top: 0;
  left: 0;
  right: 0;
  bottom: 0;
  background-color: #334155;
  transition: 0.3s;
  border-radius: 22px;
}

.slider:before {
  position: absolute;
  content: "";
  height: 16px;
  width: 16px;
  left: 3px;
  bottom: 3px;
  background-color: white;
  transition: 0.3s;
  border-radius: 50%;
}

input:checked + .slider {
  background-color: var(--accent-primary);
}

input:checked + .slider:before {
  transform: translateX(16px);
}

/* Button styles */
.btn {
  width: 100%;
  padding: 9px 16px;
  font-size: 13px;
  font-weight: 600;
  border-radius: 8px;
  border: 1px solid var(--border-color);
  background: #1e293b;
  color: var(--text-primary);
  cursor: pointer;
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 8px;
  transition: all var(--transition-speed);
}

.btn:hover {
  background: #2b3952;
  border-color: var(--border-highlight);
}

.btn.primary {
  background: var(--accent-primary);
  border-color: var(--accent-primary);
  color: #ffffff;
}

.btn.primary:hover {
  background: #4f46e5;
  box-shadow: 0 0 16px var(--accent-glow);
}

.btn.danger {
  background: rgba(239, 68, 68, 0.15);
  border-color: rgba(239, 68, 68, 0.3);
  color: #fca5a5;
}

.btn.danger:hover {
  background: rgba(239, 68, 68, 0.25);
  border-color: var(--danger);
}

/* Sidebar Toggle floating button */
.sidebar-toggle-btn {
  position: absolute;
  top: 16px;
  right: 20px;
  background: var(--bg-panel);
  backdrop-filter: blur(12px);
  -webkit-backdrop-filter: blur(12px);
  border: 1px solid var(--border-color);
  color: var(--text-primary);
  width: 38px;
  height: 38px;
  border-radius: 50%;
  display: flex;
  align-items: center;
  justify-content: center;
  cursor: pointer;
  z-index: 15;
  box-shadow: 0 4px 16px rgba(0, 0, 0, 0.4);
  transition: all var(--transition-speed);
}

.sidebar-toggle-btn:hover {
  background: rgba(40, 52, 80, 0.9);
  border-color: var(--border-highlight);
  transform: scale(1.05);
}

.click-hint {
  position: absolute;
  bottom: 20px;
  right: 20px;
  background: var(--bg-panel);
  backdrop-filter: blur(10px);
  -webkit-backdrop-filter: blur(10px);
  border: 1px solid var(--border-color);
  padding: 6px 12px;
  border-radius: 20px;
  font-size: 11px;
  color: var(--text-muted);
  pointer-events: none;
  opacity: 0.8;
}

/* Responsive adjustments */
@media (max-width: 768px) {
  #controls-sidebar {
    position: absolute;
    right: 0;
    width: 100%;
    max-width: 360px;
  }
  .chart-panel {
    display: none;
  }
}

/* Interactive On-Screen Carbon Control Rod Console */
.carbon-rod-console {
  position: absolute;
  top: 75px;
  right: 20px;
  width: 170px;
  background: rgba(13, 17, 23, 0.88);
  backdrop-filter: blur(14px);
  -webkit-backdrop-filter: blur(14px);
  border: 1px solid rgba(234, 179, 8, 0.35);
  border-radius: var(--panel-radius);
  padding: 12px;
  box-shadow: 0 8px 28px rgba(0, 0, 0, 0.5), 0 0 15px rgba(234, 179, 8, 0.1);
  z-index: 12;
  display: flex;
  flex-direction: column;
  gap: 10px;
  user-select: none;
  transition: opacity 0.25s ease, transform 0.25s ease;
}

.carbon-rod-console.hidden {
  opacity: 0;
  pointer-events: none;
  transform: translateX(30px) scale(0.95);
}

.rod-console-header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  border-bottom: 1px solid rgba(255, 255, 255, 0.08);
  padding-bottom: 6px;
}

.rod-title {
  font-size: 10px;
  font-weight: 800;
  letter-spacing: 0.08em;
  color: #facc15;
  text-transform: uppercase;
}

.rod-status-badge {
  font-size: 8px;
  font-weight: 800;
  padding: 2px 6px;
  border-radius: 10px;
  background: rgba(234, 179, 8, 0.2);
  color: #fde047;
  border: 1px solid rgba(234, 179, 8, 0.4);
  letter-spacing: 0.05em;
}

.rod-status-badge.scram {
  background: rgba(239, 68, 68, 0.25);
  color: #fca5a5;
  border-color: rgba(239, 68, 68, 0.6);
  animation: pulse-border 1s infinite alternate;
}

.rod-slider-container {
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 4px;
  padding: 4px 0;
}

.rod-limit-label {
  font-size: 8px;
  font-weight: 700;
  color: var(--text-muted);
  letter-spacing: 0.05em;
}

.rod-track-wrapper {
  position: relative;
  width: 100%;
  height: 120px;
  display: flex;
  justify-content: center;
  align-items: center;
}

/* Vertical range slider */
.vertical-rod-slider {
  -webkit-appearance: none;
  appearance: none;
  width: 110px;
  height: 14px;
  transform: rotate(90deg);
  background: #161b22;
  border-radius: 7px;
  outline: none;
  border: 1px solid #30363d;
  cursor: grab;
  box-shadow: inset 0 2px 4px rgba(0, 0, 0, 0.5);
}

.vertical-rod-slider:active {
  cursor: grabbing;
}

.vertical-rod-slider::-webkit-slider-thumb {
  -webkit-appearance: none;
  appearance: none;
  width: 22px;
  height: 22px;
  border-radius: 50%;
  background: #facc15;
  border: 2px solid #0d1117;
  box-shadow: 0 0 10px rgba(250, 204, 21, 0.8);
  cursor: grab;
  transition: transform 0.1s ease;
}

.vertical-rod-slider::-webkit-slider-thumb:hover {
  transform: scale(1.15);
}

.vertical-rod-slider::-moz-range-thumb {
  width: 22px;
  height: 22px;
  border-radius: 50%;
  background: #facc15;
  border: 2px solid #0d1117;
  box-shadow: 0 0 10px rgba(250, 204, 21, 0.8);
  cursor: grab;
}

.rod-telemetry {
  display: flex;
  justify-content: space-between;
  background: rgba(0, 0, 0, 0.3);
  padding: 6px 8px;
  border-radius: 6px;
  border: 1px solid rgba(255, 255, 255, 0.05);
}

.rod-stat {
  display: flex;
  flex-direction: column;
}

.rod-stat .lbl {
  font-size: 7.5px;
  font-weight: 700;
  color: var(--text-muted);
  letter-spacing: 0.05em;
}

.rod-stat .val {
  font-family: var(--font-mono);
  font-size: 13px;
  font-weight: 800;
  color: var(--text-primary);
}

.rod-stat .val.highlight {
  color: #38bdf8;
}

.rod-action-buttons {
  display: flex;
  gap: 6px;
}

.rod-btn {
  flex: 1;
  padding: 5px 0;
  border-radius: 6px;
  font-size: 9.5px;
  font-weight: 800;
  cursor: pointer;
  border: 1px solid transparent;
  transition: all 0.2s ease;
  text-align: center;
  letter-spacing: 0.04em;
}

.rod-btn.scram {
  background: rgba(220, 38, 38, 0.25);
  color: #fca5a5;
  border-color: rgba(239, 68, 68, 0.5);
}

.rod-btn.scram:hover {
  background: rgba(220, 38, 38, 0.45);
  border-color: #ef4444;
  color: #fff;
  box-shadow: 0 0 12px rgba(239, 68, 68, 0.6);
}

.rod-btn.withdraw {
  background: rgba(31, 41, 55, 0.6);
  color: var(--text-secondary);
  border-color: var(--border-color);
}

.rod-btn.withdraw:hover {
  background: rgba(55, 65, 81, 0.8);
  color: var(--text-primary);
}