:root {
  /* ── Enterprise Color System ─────────────────────────────────── */
  --color-primary: #5e6ad2;
  --color-primary-hover: #6e7ae0;
  --color-primary-active: #4d5ab8;
  --color-primary-subtle: rgba(94, 106, 210, 0.1);
  --color-primary-glow: rgba(94, 106, 210, 0.2);

  /* Surfaces — cool dark with slight blue tint */
  --color-bg-canvas: #07070f;
  --color-bg-deep: rgba(11, 11, 20, 0.97);
  --color-bg-surface: rgba(255, 255, 255, 0.04);
  --color-bg-elevated: rgba(255, 255, 255, 0.06);
  --color-bg-toolbar: rgba(13, 13, 21, 0.94);

  /* Borders */
  --color-border: rgba(255, 255, 255, 0.07);
  --color-border-light: rgba(255, 255, 255, 0.04);
  --color-border-focus: rgba(94, 106, 210, 0.5);
  --color-border-subtle: rgba(255, 255, 255, 0.05);

  /* Text hierarchy */
  --color-text-main: #eeeef6;
  --color-text-secondary: #c2c2d8;
  --color-text-dim: #9494b4;
  --color-text-muted: #64647e;
  --color-text-disabled: #3a3a54;

  /* Node category accent colors — desaturated for enterprise */
  --color-node-default: #252535;
  --color-node-logic: #3d1d66;
  --color-node-action: #0e3828;
  --color-node-data: #0e2550;
  --color-node-info: #1a1a44;
  --color-node-event: #3d2608;
  --color-node-math: #3d0d2d;

  /* Status */
  --color-success: #16a34a;
  --color-warning: #d97706;
  --color-error: #dc2626;

  /* Typography */
  --font-main: "Inter", system-ui, -apple-system, BlinkMacSystemFont, sans-serif;
  --font-mono: "JetBrains Mono", "SF Mono", "Cascadia Code", "Fira Code", monospace;

  /* Geometry */
  --radius-xs: 2px;
  --radius-sm: 3px;
  --radius-md: 4px;
  --radius-lg: 6px;
  --radius-xl: 10px;

  /* Shadows */
  --shadow-xs: 0 1px 2px rgba(0, 0, 0, 0.6);
  --shadow-sm: 0 2px 6px rgba(0, 0, 0, 0.5);
  --shadow-md: 0 4px 16px rgba(0, 0, 0, 0.55);
  --shadow-lg: 0 12px 36px rgba(0, 0, 0, 0.7);
  --shadow-xl: 0 24px 64px rgba(0, 0, 0, 0.85);
}

/* ── Reset & Base ─────────────────────────────────────────────── */
*, *::before, *::after {
  box-sizing: border-box;
}

html, body {
  height: 100%;
  margin: 0;
  overflow: hidden;
  font-family: var(--font-main);
  background-color: #07070f;
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
}

#wrap {
  height: 100%;
  width: 100%;
  display: flex;
  overflow: hidden;
}

.content-root {
  width: 100%;
  height: 100%;
  position: relative;
  overflow: hidden;
}

#cv {
  width: 100%;
  height: 100%;
  display: block;
  position: absolute;
  top: 0;
  left: 0;
}

/* ── Toolbar ─────────────────────────────────────────────────── */
#toolbar {
  z-index: 1000;
  position: absolute;
  top: 14px;
  left: 14px;
  display: flex;
  gap: 2px;
  align-items: center;
  padding: 5px 8px;
  background: var(--color-bg-toolbar);
  backdrop-filter: blur(16px) saturate(180%);
  -webkit-backdrop-filter: blur(16px) saturate(180%);
  border-radius: var(--radius-lg);
  border: 1px solid var(--color-border);
  box-shadow: var(--shadow-sm), 0 0 0 0.5px rgba(255,255,255,0.04) inset;
  font-size: 12px;
  color: var(--color-text-muted);
}

#toolbar button {
  padding: 4px 9px;
  background: transparent;
  color: var(--color-text-muted);
  border: 1px solid transparent;
  border-radius: var(--radius-sm);
  font-size: 11px;
  font-weight: 500;
  font-family: var(--font-main);
  cursor: pointer;
  letter-spacing: 0.3px;
  transition: color 0.1s, background 0.1s, border-color 0.1s;
  margin: 0;
  white-space: nowrap;
  line-height: 1.4;
}

#toolbar button:hover {
  background: var(--color-bg-elevated);
  color: var(--color-text-secondary);
  border-color: var(--color-border);
}

#toolbar button:active {
  background: rgba(255, 255, 255, 0.04);
  color: var(--color-text-dim);
}

.toolbar-sep {
  width: 1px;
  height: 14px;
  background: var(--color-border);
  margin: 0 4px;
  flex-shrink: 0;
  opacity: 0.6;
}

#toolbar label {
  display: flex;
  align-items: center;
  gap: 5px;
  cursor: pointer;
  color: var(--color-text-muted);
  font-size: 11px;
  padding: 0 2px;
}

#toolbar select {
  padding: 3px 22px 3px 7px;
  background: transparent;
  border: 1px solid var(--color-border);
  border-radius: var(--radius-sm);
  color: var(--color-text-dim);
  font-size: 11px;
  font-family: var(--font-main);
  cursor: pointer;
  outline: none;
  transition: border-color 0.15s, color 0.15s;
  appearance: none;
  background-image: url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' width='10' height='10' viewBox='0 0 24 24' fill='none' stroke='%2364647e' stroke-width='2' stroke-linecap='round' stroke-linejoin='round'%3E%3Cpath d='m6 9 6 6 6-6'/%3E%3C/svg%3E");
  background-repeat: no-repeat;
  background-position: right 6px center;
}

#toolbar select option {
  background: #1a1a28;
  color: var(--color-text-secondary);
}

#toolbar select:hover {
  border-color: var(--color-border-focus);
  color: var(--color-text-secondary);
}

#toolbar select:focus {
  border-color: var(--color-primary);
  box-shadow: 0 0 0 2px var(--color-primary-glow);
}

/* Snap / Status indicator */
.indicator {
  padding: 3px 7px;
  background: transparent;
  border: 1px solid rgba(255, 255, 255, 0.05);
  border-radius: var(--radius-sm);
  font-size: 10px;
  font-weight: 600;
  font-family: var(--font-mono);
  letter-spacing: 0.5px;
  color: var(--color-text-disabled);
  text-transform: uppercase;
  transition: color 0.15s, border-color 0.15s, background 0.15s;
  user-select: none;
}

.indicator.active {
  color: var(--color-primary-hover);
  border-color: rgba(94, 106, 210, 0.35);
  background: var(--color-primary-subtle);
}

/* ── Mode Toggle ─────────────────────────────────────────────── */
.mode-toggle {
  display: flex;
  background: rgba(0, 0, 0, 0.25);
  padding: 2px;
  border-radius: var(--radius-sm);
  gap: 1px;
}

.mode-toggle button {
  padding: 3px 11px !important;
  font-size: 10px !important;
  text-transform: uppercase;
  letter-spacing: 0.6px;
  border: 1px solid transparent !important;
  opacity: 0.45;
  font-weight: 600 !important;
}

.mode-toggle button:hover {
  opacity: 0.85;
  background: rgba(255, 255, 255, 0.04) !important;
}

.mode-toggle button.active {
  opacity: 1;
  border-radius: 2px !important;
}

/* Run mode — emerald */
.mode-toggle button[data-mode="run"].active {
  color: #22c55e !important;
  background: rgba(34, 197, 94, 0.08) !important;
  border-color: rgba(34, 197, 94, 0.25) !important;
}

/* Step mode — violet */
.mode-toggle button[data-mode="step"].active {
  color: #8b8ef8 !important;
  background: rgba(139, 142, 248, 0.08) !important;
  border-color: rgba(139, 142, 248, 0.25) !important;
}

/* ── Zoom Controls ───────────────────────────────────────────── */
.zoom-controls {
  display: flex;
  align-items: center;
  gap: 1px;
}

.zoom-controls button {
  width: 22px;
  height: 22px;
  padding: 0 !important;
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 14px !important;
  font-weight: 400 !important;
  border-radius: var(--radius-xs) !important;
  line-height: 1 !important;
}

/* ── Help Overlay ─────────────────────────────────────────────── */
#helpOverlay {
  position: absolute;
  bottom: 14px;
  left: 14px;
  width: 292px;
  max-height: 480px;
  background: var(--color-bg-deep);
  backdrop-filter: blur(16px) saturate(180%);
  -webkit-backdrop-filter: blur(16px) saturate(180%);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-lg);
  padding: 14px;
  box-shadow: var(--shadow-md), var(--shadow-lg);
  font-size: 12px;
  color: var(--color-text-muted);
  overflow-y: auto;
  display: none;
  z-index: 1000;
  scrollbar-width: thin;
  scrollbar-color: rgba(255, 255, 255, 0.08) transparent;
}

#helpOverlay::-webkit-scrollbar { width: 4px; }
#helpOverlay::-webkit-scrollbar-track { background: transparent; }
#helpOverlay::-webkit-scrollbar-thumb {
  background: rgba(255, 255, 255, 0.1);
  border-radius: 10px;
}
#helpOverlay::-webkit-scrollbar-thumb:hover { background: rgba(255, 255, 255, 0.18); }

#helpOverlay.visible { display: block; }

#helpOverlay h3 {
  margin: 0 0 10px 0;
  font-size: 11px;
  font-weight: 600;
  color: var(--color-text-dim);
  border-bottom: 1px solid var(--color-border);
  padding-bottom: 8px;
  display: flex;
  justify-content: space-between;
  align-items: center;
  letter-spacing: 0.7px;
  text-transform: uppercase;
}

#helpOverlay .close-btn {
  cursor: pointer;
  font-size: 16px;
  line-height: 1;
  color: var(--color-text-disabled);
  transition: color 0.12s;
  background: none;
  border: none;
  padding: 0;
  width: 18px;
  height: 18px;
  display: flex;
  align-items: center;
  justify-content: center;
}

#helpOverlay .close-btn:hover { color: var(--color-text-dim); }

#helpOverlay h4 {
  margin: 12px 0 5px 0;
  font-size: 10px;
  color: var(--color-text-disabled);
  font-weight: 600;
  text-transform: uppercase;
  letter-spacing: 0.8px;
}

.shortcut-item {
  display: flex;
  justify-content: space-between;
  align-items: center;
  padding: 3px 4px;
  margin: 1px 0;
  border-radius: 3px;
}

.shortcut-item:hover { background: rgba(255, 255, 255, 0.025); }

.shortcut-item span:first-child {
  font-size: 11px;
  color: var(--color-text-muted);
}

.shortcut-key {
  font-family: var(--font-mono);
  font-weight: 600;
  padding: 2px 5px;
  background: rgba(255, 255, 255, 0.05);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-xs);
  font-size: 9.5px;
  color: var(--color-primary-hover);
  letter-spacing: 0.2px;
}

#helpToggle {
  position: absolute;
  bottom: 14px;
  left: 14px;
  width: 26px;
  height: 26px;
  background: var(--color-bg-toolbar);
  backdrop-filter: blur(8px);
  -webkit-backdrop-filter: blur(8px);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-sm);
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 12px;
  font-weight: 600;
  font-family: var(--font-mono);
  color: var(--color-text-disabled);
  cursor: pointer;
  box-shadow: var(--shadow-xs);
  transition: color 0.12s, border-color 0.12s, background 0.12s;
  z-index: 1000;
  user-select: none;
}

#helpToggle:hover {
  color: var(--color-text-dim);
  border-color: rgba(255, 255, 255, 0.12);
}

#helpToggle.active {
  color: var(--color-primary);
  border-color: rgba(94, 106, 210, 0.4);
  background: var(--color-primary-subtle);
}

/* ── Node Overlay (HTML nodes) ────────────────────────────────── */
.node-overlay {
  border-radius: var(--radius-md);
  pointer-events: none;
}

.node-body {
  padding-top: 10px;
}

.node-header-accent {
  display: none;
}

/* ── Premium Form Components ──────────────────────────────────── */
.premium-input {
  width: 100%;
  padding: 6px 9px;
  background: rgba(0, 0, 0, 0.45) !important;
  border: 1px solid rgba(255, 255, 255, 0.09) !important;
  border-radius: var(--radius-sm) !important;
  color: var(--color-text-main) !important;
  font-size: 11px !important;
  font-family: var(--font-mono) !important;
  outline: none !important;
  transition: border-color 0.15s, background 0.15s, box-shadow 0.15s !important;
  box-sizing: border-box !important;
  pointer-events: auto !important;
  line-height: 1.4 !important;
}

.premium-input::placeholder {
  color: var(--color-text-disabled) !important;
}

.premium-input:focus {
  border-color: var(--color-primary) !important;
  background: rgba(0, 0, 0, 0.6) !important;
  box-shadow: 0 0 0 2px var(--color-primary-glow) !important;
}

.premium-button {
  padding: 5px 12px;
  background: var(--color-primary-subtle);
  border: 1px solid rgba(94, 106, 210, 0.28);
  border-radius: var(--radius-sm);
  color: var(--color-primary-hover);
  font-size: 11px;
  font-weight: 600;
  font-family: var(--font-main);
  cursor: pointer;
  transition: background 0.15s, color 0.15s, border-color 0.15s;
  pointer-events: auto;
  white-space: nowrap;
}

.premium-button:hover {
  background: var(--color-primary);
  color: #fff;
  border-color: var(--color-primary);
}

.premium-button:active {
  background: var(--color-primary-active);
}

.premium-label {
  color: var(--color-text-muted);
  font-size: 10px;
  font-weight: 600;
  font-family: var(--font-main);
  letter-spacing: 0.06em;
  text-transform: uppercase;
  margin-bottom: 5px;
  display: block;
}

/* ── Scrollbars (global) ─────────────────────────────────────── */
::-webkit-scrollbar { width: 5px; height: 5px; }
::-webkit-scrollbar-track { background: transparent; }
::-webkit-scrollbar-thumb {
  background: rgba(255, 255, 255, 0.1);
  border-radius: 10px;
}
::-webkit-scrollbar-thumb:hover { background: rgba(255, 255, 255, 0.18); }