/* Nexus design tokens - copied from the design system, referenced not retyped. */
:root {
  --bg-root: #020617;
  --bg-primary: #0f172a;
  --bg-secondary: #1e293b;
  --bg-tertiary: #334155;
  --border-subtle: #1e293b;
  --border-strong: #6b7a91;
  --text-primary: #f1f5f9;
  --text-secondary: #cbd5e1;
  --text-muted: #94a3b8;
  --text-faint: #64748b;
  --text-inverse: #0f172a;
  --accent: #6366f1;
  --accent-strong: #4f46e5;
  --accent-soft: #a5b4fc;
  --accent-faint: #c7d2fe;
  --ok: #10b981;
  --ok-soft: #6ee7b7;
  --warn: #f59e0b;
  --warn-soft: #fcd34d;
  --danger: #f43f5e;
  --danger-soft: #fda4af;
  --info: #06b6d4;
  --grad-from: #4f46e5;
  --grad-via: #7c3aed;
  --grad-to: #0891b2;
  --font-sans: 'Inter', system-ui, sans-serif;
  --font-mono: ui-monospace, SFMono-Regular, Menlo, monospace;
  --text-xs: 0.6875rem;
  --text-sm: 0.75rem;
  --text-md: 0.8125rem;
  --text-base: 0.875rem;
  --text-lg: 1rem;
  --text-xl: 1.25rem;
  --text-input-min: 16px;
  --leading-tight: 1.25;
  --leading-body: 1.55;
  --radius-sm: 8px;
  --radius-md: 10px;
  --radius-lg: 16px;
  --radius-pill: 999px;
  --space-unit: 4px;
  --space-1: 4px;
  --space-2: 8px;
  --space-3: 12px;
  --space-4: 16px;
  --space-5: 24px;
  --space-6: 32px;
  --space-8: 48px;
  --ground: radial-gradient(900px 520px at 12% -8%, rgb(99 102 241 / 0.07), transparent 62%),
            radial-gradient(760px 480px at 96% 108%, rgb(6 182 224 / 0.06), transparent 58%),
            var(--bg-root);
  --glass-bg: rgb(30 41 59 / 0.72);
  --glass-border: rgb(255 255 255 / 0.10);
  --glass-blur: blur(20px) saturate(140%);
  --glass-sheen: inset 0 1px 0 rgb(255 255 255 / 0.06);
  --focus-ring: 0 0 0 2px var(--bg-root), 0 0 0 4px var(--accent);
  --shadow-sm: 0 1px 2px 0 rgb(0 0 0 / 0.40);
  --shadow-md: 0 4px 12px 0 rgb(0 0 0 / 0.45);
  --shadow-lg: 0 12px 32px 0 rgb(0 0 0 / 0.55);
  --logo-url: url("https://assets.my-nexus.work/nexus-logo.svg");
}

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

html, body { height: 100%; }

body {
  font-family: var(--font-sans);
  font-size: var(--text-base);
  line-height: var(--leading-body);
  color: var(--text-primary);
  background: var(--ground);
  background-attachment: fixed;
  -webkit-font-smoothing: antialiased;
}

.app {
  display: flex;
  flex-direction: column;
  min-height: 100vh;
  max-width: 1400px;
  margin: 0 auto;
  padding: var(--space-6) var(--space-6) var(--space-8);
}

/* Header */
.header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: var(--space-4);
  margin-bottom: var(--space-6);
}

.brand {
  display: flex;
  align-items: center;
  gap: var(--space-3);
}

.brand-mark {
  width: 36px;
  height: 36px;
  background: var(--logo-url) center / contain no-repeat;
}

.brand-text h1 {
  font-size: var(--text-xl);
  font-weight: 600;
  letter-spacing: -0.01em;
  line-height: var(--leading-tight);
}

.brand-text p {
  font-size: var(--text-sm);
  color: var(--text-muted);
}

.header-actions {
  display: flex;
  gap: var(--space-2);
}

/* Toolbar */
.toolbar {
  display: flex;
  align-items: center;
  gap: var(--space-3);
  flex-wrap: wrap;
  margin-bottom: var(--space-4);
}

.toolbar-group {
  display: flex;
  align-items: center;
  gap: var(--space-2);
}

.toolbar-label {
  font-size: var(--text-sm);
  color: var(--text-muted);
  font-weight: 500;
}

/* Select */
.select {
  font-family: var(--font-sans);
  font-size: var(--text-base);
  color: var(--text-primary);
  background: var(--bg-root);
  border: 1px solid var(--border-strong);
  border-radius: var(--radius-sm);
  padding: var(--space-2) var(--space-3);
  cursor: pointer;
  box-shadow: var(--shadow-sm);
  appearance: none;
  background-image: linear-gradient(45deg, transparent 50%, var(--text-muted) 50%),
                    linear-gradient(135deg, var(--text-muted) 50%, transparent 50%);
  background-position: calc(100% - 18px) center, calc(100% - 13px) center;
  background-size: 5px 5px, 5px 5px;
  background-repeat: no-repeat;
  padding-right: var(--space-6);
}

.select:focus {
  outline: none;
  box-shadow: var(--focus-ring);
}

/* Buttons */
.btn {
  font-family: var(--font-sans);
  font-size: var(--text-base);
  font-weight: 500;
  border-radius: var(--radius-sm);
  padding: var(--space-2) var(--space-4);
  cursor: pointer;
  border: 1px solid transparent;
  display: inline-flex;
  align-items: center;
  gap: var(--space-2);
  transition: background 0.15s ease, border-color 0.15s ease;
  white-space: nowrap;
}

.btn:focus-visible {
  outline: none;
  box-shadow: var(--focus-ring);
}

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

.btn-primary:hover {
  background: var(--accent-strong);
  border-color: var(--accent-strong);
}

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

.btn-secondary {
  background: transparent;
  color: var(--text-primary);
  border-color: var(--border-strong);
}

.btn-secondary:hover {
  background: var(--bg-tertiary);
}

/* Main split */
.workspace {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: var(--space-4);
  flex: 1;
  min-height: 0;
}

@media (max-width: 900px) {
  .workspace { grid-template-columns: 1fr; }
}

.panel {
  background: var(--bg-primary);
  border: 1px solid var(--bg-secondary);
  border-radius: var(--radius-md);
  box-shadow: var(--shadow-sm);
  display: flex;
  flex-direction: column;
  min-height: 0;
  overflow: hidden;
}

.panel-header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: var(--space-3) var(--space-4);
  border-bottom: 1px solid var(--border-subtle);
  background: var(--bg-primary);
}

.panel-title {
  font-size: var(--text-sm);
  font-weight: 600;
  color: var(--text-secondary);
  text-transform: uppercase;
  letter-spacing: 0.04em;
}

.panel-meta {
  font-size: var(--text-xs);
  color: var(--text-faint);
  font-family: var(--font-mono);
}

/* Editor */
.editor-wrap {
  position: relative;
  flex: 1;
  display: flex;
  min-height: 0;
}

.code-input {
  width: 100%;
  flex: 1;
  font-family: var(--font-mono);
  font-size: var(--text-input-min);
  line-height: var(--leading-body);
  color: var(--text-primary);
  background: var(--bg-root);
  border: none;
  border-radius: 0;
  padding: var(--space-4);
  resize: none;
  outline: none;
  tab-size: 2;
}

.code-input::placeholder {
  color: var(--text-faint);
}

.code-input:focus {
  box-shadow: inset 0 0 0 2px var(--accent);
}

/* Diagram panel */
.diagram-body {
  flex: 1;
  overflow: auto;
  padding: var(--space-5);
  display: flex;
  align-items: flex-start;
  justify-content: center;
  background: var(--bg-root);
  position: relative;
  min-height: 0;
}

.diagram-body.has-diagram {
  align-items: center;
}

/* Empty state */
.empty-state {
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: var(--space-3);
  color: var(--text-muted);
  text-align: center;
  padding: var(--space-8);
}

.empty-state-icon {
  width: 64px;
  height: 64px;
  background: var(--logo-url) center / contain no-repeat;
  opacity: 0.4;
}

.empty-state h2 {
  font-size: var(--text-lg);
  font-weight: 600;
  color: var(--text-secondary);
}

.empty-state p {
  font-size: var(--text-sm);
  max-width: 320px;
}

/* Rendered diagram */
#diagram-output {
  width: 100%;
  display: flex;
  justify-content: center;
}

#diagram-output svg {
  max-width: 100%;
  height: auto;
}

/* Error */
.error-box {
  display: none;
  align-items: flex-start;
  gap: var(--space-3);
  margin: var(--space-4);
  padding: var(--space-4);
  background: rgb(244 63 94 / 0.08);
  border: 1px solid rgb(244 63 94 / 0.30);
  border-radius: var(--radius-sm);
  color: var(--danger-soft);
  font-family: var(--font-mono);
  font-size: var(--text-sm);
  line-height: var(--leading-body);
}

.error-box.show {
  display: flex;
}

.error-box-icon {
  flex-shrink: 0;
  width: 18px;
  height: 18px;
  margin-top: 1px;
}

/* Loading */
.nexus-loading {
  display: none;
  place-items: center;
  gap: 12px;
  min-height: 120px;
  color: var(--text-muted);
  font-family: var(--font-sans);
  font-size: 13px;
}

.nexus-loading.show {
  display: grid;
}

.nexus-loading::before {
  content: "";
  width: 44px;
  height: 44px;
  background: var(--logo-url) center / contain no-repeat;
  animation: nexus-pulse 1.4s ease-in-out infinite;
}

@keyframes nexus-pulse {
  0%, 100% { opacity: .35; transform: scale(.94); }
  50%      { opacity: 1;   transform: scale(1); }
}

@media (prefers-reduced-motion: reduce) {
  .nexus-loading::before { animation: none; opacity: .7; }
}

/* Footer hint */
.footer-hint {
  margin-top: var(--space-4);
  font-size: var(--text-xs);
  color: var(--text-faint);
  text-align: center;
}

.footer-hint code {
  font-family: var(--font-mono);
  color: var(--text-muted);
  background: var(--bg-secondary);
  padding: 1px 6px;
  border-radius: 4px;
}