/* ==========================================================================
   RFx Atlas — Interactive Architecture Viewer CSS (shared viewer theme)
   Enterprise dark theme with Palo Alto Networks accents
   ========================================================================== */

:root {
  --bg-dark: #070B14;
  --bg-canvas: #0B0F19;
  --bg-panel: rgba(15, 23, 42, 0.85);
  --bg-panel-solid: #0F172A;
  --bg-card: rgba(30, 41, 59, 0.7);
  --bg-hover: rgba(51, 65, 85, 0.6);
  
  --border-color: #1E293B;
  --border-light: #334155;
  --border-focus: #38BDF8;

  --text-main: #F8FAFC;
  --text-muted: #94A3B8;
  --text-dim: #64748B;

  /* Brand Accents */
  --panw-orange: #FA582D;
  --panw-orange-glow: rgba(250, 88, 45, 0.4);
  --panw-flame: #FF6B35;
  --aws-squid: #232F3E;
  --aws-orange: #FF9900;
  --aws-purple: #A855F7;
  
  /* Status Colors */
  --status-active: #10B981;
  --status-passive: #64748B;
  --status-failure: #EF4444;
  --status-action: #F59E0B;
  --status-cyan: #00F0FF;
  
  --font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, Helvetica, Arial, sans-serif, "Apple Color Emoji";
  --font-mono: "JetBrains Mono", "Fira Code", SFMono-Regular, Menlo, Monaco, Consolas, monospace;

  --shadow-panel: 0 20px 25px -5px rgba(0, 0, 0, 0.5), 0 8px 10px -6px rgba(0, 0, 0, 0.5);
  --radius-sm: 6px;
  --radius-md: 10px;
  --radius-lg: 16px;
}

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

body {
  font-family: var(--font-family);
  background-color: var(--bg-dark);
  color: var(--text-main);
  overflow: hidden;
  height: 100vh;
  width: 100vw;
  display: flex;
  flex-direction: column;
  -webkit-font-smoothing: antialiased;
}

/* ==========================================================================
   Header Bar
   ========================================================================== */
.app-header {
  height: 64px;
  background-color: var(--bg-panel-solid);
  border-bottom: 1px solid var(--border-color);
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 0 20px;
  z-index: 100;
  box-shadow: 0 4px 12px rgba(0, 0, 0, 0.3);
}

.header-left {
  display: flex;
  align-items: center;
  gap: 16px;
}

.brand-logos {
  display: flex;
  align-items: center;
  gap: 8px;
}

.brand-logos svg {
  width: 34px;
  height: 34px;
}

.brand-divider {
  width: 1px;
  height: 24px;
  background-color: var(--border-light);
}

.project-titles h1 {
  font-size: 16px;
  font-weight: 700;
  letter-spacing: -0.01em;
  display: flex;
  align-items: center;
  gap: 8px;
}

.project-titles h1 .badge-ver {
  font-size: 11px;
  font-weight: 600;
  padding: 2px 8px;
  background-color: rgba(250, 88, 45, 0.15);
  color: var(--panw-orange);
  border: 1px solid rgba(250, 88, 45, 0.3);
  border-radius: 12px;
}

.project-titles p {
  font-size: 12px;
  color: var(--text-muted);
}

/* Mode Switcher Tabs */
.header-center {
  display: flex;
  align-items: center;
  background: var(--bg-card);
  padding: 4px;
  border-radius: var(--radius-md);
  border: 1px solid var(--border-color);
}

.mode-tab {
  display: flex;
  align-items: center;
  gap: 8px;
  padding: 8px 14px;
  border-radius: var(--radius-sm);
  font-size: 13px;
  font-weight: 500;
  color: var(--text-muted);
  cursor: pointer;
  transition: all 0.2s ease;
  border: none;
  background: transparent;
}

.mode-tab:hover {
  color: var(--text-main);
  background-color: var(--bg-hover);
}

.mode-tab.active {
  color: #fff;
  background-color: var(--panw-orange);
  box-shadow: 0 2px 8px var(--panw-orange-glow);
}

.mode-tab svg {
  width: 16px;
  height: 16px;
  stroke: currentColor;
}

/* Header Right Actions */
.header-right {
  display: flex;
  align-items: center;
  gap: 12px;
}

.lang-switch-group {
  display: flex;
  align-items: center;
  background: var(--bg-card);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-sm);
  padding: 2px;
  gap: 2px;
}

.btn-lang {
  padding: 4px 8px;
  font-size: 11px;
  font-weight: 700;
  color: var(--text-muted);
  border: none;
  background: transparent;
  border-radius: 4px;
  cursor: pointer;
  transition: all 0.2s ease;
  text-decoration: none;
}

.btn-lang:hover {
  color: var(--text-main);
  background: var(--bg-hover);
}

.btn-lang.active {
  color: #FFFFFF;
  background: var(--panw-orange);
  box-shadow: 0 0 6px var(--panw-orange-glow);
}

.search-box {
  position: relative;
  display: flex;
  align-items: center;
}

.search-box svg {
  position: absolute;
  left: 10px;
  width: 16px;
  height: 16px;
  stroke: var(--text-dim);
}

.search-box input {
  background: var(--bg-card);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-sm);
  padding: 6px 12px 6px 32px;
  color: var(--text-main);
  font-size: 12px;
  width: 180px;
  transition: all 0.2s ease;
}

.search-box input:focus {
  outline: none;
  border-color: var(--border-focus);
  width: 240px;
  background: var(--bg-dark);
}

.btn-icon {
  width: 36px;
  height: 36px;
  border-radius: var(--radius-sm);
  background: var(--bg-card);
  border: 1px solid var(--border-color);
  color: var(--text-muted);
  display: flex;
  align-items: center;
  justify-content: center;
  cursor: pointer;
  transition: all 0.2s ease;
}

.btn-icon:hover {
  color: var(--text-main);
  border-color: var(--border-light);
  background: var(--bg-hover);
}

.btn-icon svg {
  width: 18px;
  height: 18px;
  stroke: currentColor;
}

.btn-repo {
  display: flex;
  align-items: center;
  gap: 6px;
  padding: 6px 12px;
  background: var(--bg-card);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-sm);
  color: var(--text-main);
  text-decoration: none;
  font-size: 12px;
  font-weight: 500;
  transition: all 0.2s ease;
}

.btn-repo:hover {
  background: var(--bg-hover);
  border-color: var(--border-light);
}

/* ==========================================================================
   Main Layout Container
   ========================================================================== */
.app-container {
  position: relative;
  flex: 1;
  display: flex;
  overflow: hidden;
  background-color: var(--bg-canvas);
  background-image: 
    radial-gradient(circle at 50% 50%, rgba(30, 41, 59, 0.4) 0%, transparent 80%),
    linear-gradient(to right, rgba(255, 255, 255, 0.02) 1px, transparent 1px),
    linear-gradient(to bottom, rgba(255, 255, 255, 0.02) 1px, transparent 1px);
  background-size: 100% 100%, 32px 32px, 32px 32px;
}

/* Diagram Canvas Area */
.diagram-viewport {
  position: absolute;
  top: 0;
  left: 0;
  width: 100%;
  height: 100%;
  cursor: grab;
  user-select: none;
}

.diagram-viewport:active {
  cursor: grabbing;
}

#architecture-svg {
  width: 100%;
  height: 100%;
}

/* Canvas Viewport Controls */
.viewport-controls {
  position: absolute;
  bottom: 24px;
  right: 24px;
  display: flex;
  flex-direction: column;
  gap: 6px;
  z-index: 50;
  background: var(--bg-panel);
  backdrop-filter: blur(12px);
  padding: 6px;
  border-radius: var(--radius-md);
  border: 1px solid var(--border-color);
  box-shadow: var(--shadow-panel);
}

.quick-nav-bar {
  position: absolute;
  top: 16px;
  right: 20px;
  display: flex;
  align-items: center;
  gap: 6px;
  z-index: 50;
  background: var(--bg-panel);
  backdrop-filter: blur(14px);
  padding: 5px 10px;
  border-radius: var(--radius-md);
  border: 1px solid var(--border-color);
  box-shadow: var(--shadow-panel);
}

.nav-label {
  font-size: 11px;
  font-weight: 700;
  color: var(--text-dim);
  text-transform: uppercase;
  letter-spacing: 0.05em;
  margin-right: 2px;
}

.nav-btn {
  font-size: 11.5px;
  font-weight: 600;
  padding: 5px 10px;
  border-radius: var(--radius-sm);
  background: transparent;
  color: var(--text-muted);
  border: 1px solid transparent;
  cursor: pointer;
  transition: all 0.2s ease;
  white-space: nowrap;
}

.nav-btn:hover {
  background: var(--bg-hover);
  color: var(--text-main);
  border-color: var(--border-light);
}

.nav-btn.active {
  background: var(--border-light);
  color: #FFFFFF;
  border-color: var(--border-focus);
  box-shadow: 0 0 10px rgba(56, 189, 248, 0.25);
}

/* ==========================================================================
   Left Interactive Control Panel
   ========================================================================== */
.left-panel {
  position: absolute;
  top: 20px;
  left: 20px;
  width: 360px;
  max-height: calc(100vh - 120px);
  background: var(--bg-panel);
  backdrop-filter: blur(16px);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-lg);
  box-shadow: var(--shadow-panel);
  z-index: 60;
  display: flex;
  flex-direction: column;
  overflow: hidden;
  transition: transform 0.3s cubic-bezier(0.16, 1, 0.3, 1);
}

.left-panel.collapsed {
  transform: translateX(-380px);
}

.panel-header {
  padding: 16px 20px;
  border-bottom: 1px solid var(--border-color);
  display: flex;
  align-items: center;
  justify-content: space-between;
}

.panel-header h2 {
  font-size: 14px;
  font-weight: 700;
  display: flex;
  align-items: center;
  gap: 8px;
  color: var(--text-main);
}

.panel-header h2 svg {
  width: 18px;
  height: 18px;
  color: var(--panw-orange);
}

.panel-content {
  padding: 16px 20px;
  overflow-y: auto;
  flex: 1;
  display: flex;
  flex-direction: column;
  gap: 16px;
}

/* Flow Selector Options */
.flow-list {
  display: flex;
  flex-direction: column;
  gap: 8px;
}

.flow-card {
  padding: 12px;
  background: var(--bg-card);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-md);
  cursor: pointer;
  transition: all 0.2s ease;
  display: flex;
  flex-direction: column;
  gap: 4px;
}

.flow-card:hover {
  background: var(--bg-hover);
  border-color: var(--border-light);
}

.flow-card.active {
  border-color: var(--flow-color, var(--panw-orange));
  background: rgba(30, 41, 59, 0.9);
  box-shadow: 0 0 16px rgba(0, 240, 255, 0.15);
}

.flow-title {
  font-size: 13px;
  font-weight: 600;
  color: var(--text-main);
  display: flex;
  align-items: center;
  justify-content: space-between;
}

.flow-desc {
  font-size: 11px;
  color: var(--text-muted);
  line-height: 1.4;
}

/* Step Narration Card */
.narration-box {
  background: rgba(11, 15, 25, 0.8);
  border: 1px solid var(--border-light);
  border-radius: var(--radius-md);
  padding: 14px;
  margin-top: 10px;
}

.narration-step-indicator {
  font-size: 11px;
  font-weight: 700;
  text-transform: uppercase;
  color: var(--panw-orange);
  letter-spacing: 0.05em;
  margin-bottom: 4px;
}

.narration-title {
  font-size: 13px;
  font-weight: 600;
  color: #fff;
  margin-bottom: 6px;
}

.narration-body {
  font-size: 12px;
  color: var(--text-muted);
  line-height: 1.5;
}

.playback-controls {
  display: flex;
  align-items: center;
  justify-content: space-between;
  margin-top: 12px;
  padding-top: 10px;
  border-top: 1px solid var(--border-color);
}

.btn-playback {
  padding: 6px 12px;
  background: var(--bg-card);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-sm);
  color: var(--text-main);
  font-size: 12px;
  font-weight: 600;
  cursor: pointer;
  transition: all 0.2s ease;
}

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

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

/* Scenarios Cards */
.scenario-card {
  padding: 14px;
  background: var(--bg-card);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-md);
  cursor: pointer;
  transition: all 0.2s ease;
}

.scenario-card:hover {
  border-color: var(--border-light);
  background: var(--bg-hover);
}

.scenario-card.active {
  border-color: var(--status-failure);
  background: rgba(239, 68, 68, 0.08);
}

.scenario-header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  margin-bottom: 6px;
}

.scenario-tag {
  font-size: 10px;
  font-weight: 700;
  padding: 2px 6px;
  border-radius: 4px;
  background: rgba(239, 68, 68, 0.2);
  color: var(--status-failure);
}

.scenario-title {
  font-size: 13px;
  font-weight: 600;
  color: #fff;
  margin-bottom: 4px;
}

.scenario-desc {
  font-size: 11px;
  color: var(--text-muted);
  line-height: 1.4;
}

/* ==========================================================================
   Right Detail Drawer (Component Technical Spec)
   ========================================================================== */
.right-drawer {
  position: absolute;
  top: 20px;
  right: 20px;
  width: 420px;
  max-height: calc(100vh - 120px);
  background: var(--bg-panel);
  backdrop-filter: blur(16px);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-lg);
  box-shadow: var(--shadow-panel);
  z-index: 60;
  display: flex;
  flex-direction: column;
  overflow: hidden;
  transform: translateX(460px);
  transition: transform 0.3s cubic-bezier(0.16, 1, 0.3, 1);
}

.right-drawer.open {
  transform: translateX(0);
}

.drawer-header {
  padding: 16px 20px;
  border-bottom: 1px solid var(--border-color);
  display: flex;
  align-items: center;
  justify-content: space-between;
}

.drawer-title-group {
  display: flex;
  align-items: center;
  gap: 12px;
}

.drawer-icon {
  width: 40px;
  height: 40px;
}

.drawer-title-group h3 {
  font-size: 15px;
  font-weight: 700;
  color: #fff;
}

.drawer-title-group span {
  font-size: 11px;
  color: var(--text-muted);
}

.drawer-body {
  padding: 20px;
  overflow-y: auto;
  flex: 1;
}

.drawer-summary {
  font-size: 13px;
  color: var(--text-main);
  line-height: 1.5;
  margin-bottom: 20px;
  background: rgba(30, 41, 59, 0.5);
  padding: 12px;
  border-radius: var(--radius-md);
  border-left: 3px solid var(--panw-orange);
}

.spec-table {
  width: 100%;
  border-collapse: collapse;
}

.spec-table th, .spec-table td {
  padding: 10px 12px;
  font-size: 12px;
  text-align: left;
  border-bottom: 1px solid var(--border-color);
}

.spec-table th {
  color: var(--text-dim);
  font-weight: 600;
  width: 35%;
}

.spec-table td {
  color: var(--text-main);
  font-family: var(--font-mono);
  word-break: break-word;
}

/* ==========================================================================
   Presentation Walkthrough Mode Bottom Bar
   ========================================================================== */
.presentation-bar {
  position: absolute;
  bottom: 24px;
  left: 50%;
  transform: translateX(-50%);
  width: min(840px, 90vw);
  background: var(--bg-panel);
  backdrop-filter: blur(16px);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-lg);
  box-shadow: var(--shadow-panel);
  z-index: 70;
  padding: 16px 24px;
  display: flex;
  flex-direction: column;
  gap: 12px;
  transition: all 0.3s ease;
}

.presentation-bar.hidden {
  opacity: 0;
  pointer-events: none;
  transform: translate(-50%, 40px);
}

.presentation-header {
  display: flex;
  align-items: center;
  justify-content: space-between;
}

.slide-counter {
  font-size: 12px;
  font-weight: 700;
  color: var(--panw-orange);
  text-transform: uppercase;
  letter-spacing: 0.05em;
}

.presentation-title {
  font-size: 16px;
  font-weight: 700;
  color: #fff;
}

.presentation-content {
  font-size: 13px;
  color: var(--text-muted);
  line-height: 1.6;
  max-height: 160px;
  overflow-y: auto;
}

.presentation-content h4 {
  color: #fff;
  font-size: 14px;
  margin-bottom: 6px;
}

.presentation-content ul, .presentation-content ol {
  margin-left: 20px;
  margin-top: 6px;
  margin-bottom: 6px;
}

.callout-box {
  background: rgba(30, 41, 59, 0.7);
  border-left: 3px solid var(--panw-orange);
  padding: 10px 14px;
  border-radius: var(--radius-sm);
  margin-top: 8px;
  font-size: 12px;
  color: var(--text-main);
}

.callout-box.warning {
  border-left-color: var(--status-action);
}

.presentation-actions {
  display: flex;
  align-items: center;
  justify-content: space-between;
  border-top: 1px solid var(--border-color);
  padding-top: 12px;
}

.benefits-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 12px;
  margin-top: 10px;
}

.benefit-card {
  background: var(--bg-card);
  padding: 10px;
  border-radius: var(--radius-sm);
  border: 1px solid var(--border-color);
}

.benefit-card .badge {
  display: inline-block;
  font-size: 10px;
  font-weight: 700;
  padding: 2px 6px;
  border-radius: 4px;
  background: rgba(16, 185, 129, 0.2);
  color: var(--status-active);
  margin-bottom: 4px;
}

.benefit-card h5 {
  font-size: 12px;
  color: #fff;
  margin-bottom: 2px;
}

.benefit-card p {
  font-size: 11px;
  color: var(--text-muted);
  line-height: 1.3;
}

/* ==========================================================================
   SVG Architecture Diagram Elements Styling
   ========================================================================== */
.region-box {
  fill: rgba(15, 23, 42, 0.5);
  stroke: #334155;
  stroke-width: 2;
  rx: 16;
  transition: all 0.3s ease;
}

.region-box.region-a {
  stroke: #475569;
}

.region-box.region-b {
  stroke: #334155;
  stroke-dasharray: 6 6;
}

.region-label {
  font-size: 15px;
  font-weight: 700;
  fill: #F8FAFC;
  letter-spacing: 0.02em;
}

.region-sublabel {
  font-size: 11px;
  font-weight: 500;
  fill: #94A3B8;
}

/* VPC Boxes */
.vpc-box {
  fill: rgba(30, 41, 59, 0.4);
  stroke: #475569;
  stroke-width: 1.5;
  rx: 12;
  transition: all 0.2s ease;
}

.vpc-box.security-vpc {
  fill: rgba(250, 88, 45, 0.04);
  stroke: rgba(250, 88, 45, 0.4);
}

.vpc-box.mgmt-vpc {
  fill: rgba(56, 189, 248, 0.04);
  stroke: rgba(56, 189, 248, 0.4);
}

.vpc-box.spoke-vpc {
  fill: rgba(168, 85, 247, 0.04);
  stroke: rgba(168, 85, 247, 0.4);
}

.vpc-title {
  font-size: 12px;
  font-weight: 700;
  fill: #E2E8F0;
}

.vpc-cidr {
  font-size: 10px;
  font-family: var(--font-mono);
  fill: #94A3B8;
}

/* Subnet Boxes */
.subnet-box {
  fill: rgba(15, 23, 42, 0.6);
  stroke: #334155;
  stroke-width: 1;
  rx: 8;
  transition: all 0.2s ease;
}

.subnet-label {
  font-size: 10px;
  font-weight: 600;
  fill: #94A3B8;
}

.subnet-cidr {
  font-size: 9px;
  font-family: var(--font-mono);
  fill: #64748B;
}

/* Node Elements */
.arch-node {
  cursor: pointer;
  transition: transform 0.2s ease, filter 0.2s ease;
}

.arch-node:hover {
  filter: drop-shadow(0 0 10px rgba(56, 189, 248, 0.5));
}

.arch-node.selected rect {
  stroke: var(--border-focus) !important;
  stroke-width: 2.5 !important;
}

.arch-node.highlighted {
  filter: drop-shadow(0 0 14px rgba(250, 88, 45, 0.8));
}

.arch-node.failing {
  animation: pulse-fail 1.2s infinite;
}

@keyframes pulse-fail {
  0% { filter: drop-shadow(0 0 6px rgba(239, 68, 68, 0.6)); }
  50% { filter: drop-shadow(0 0 18px rgba(239, 68, 68, 1)); }
  100% { filter: drop-shadow(0 0 6px rgba(239, 68, 68, 0.6)); }
}

.node-card {
  fill: #1E293B;
  stroke: #475569;
  stroke-width: 1.5;
  rx: 8;
}

.node-card.fw-active {
  fill: #1E293B;
  stroke: var(--status-active);
  stroke-width: 2;
}

.node-card.fw-passive {
  fill: #131D2D;
  stroke: #475569;
  stroke-dasharray: 4 4;
}

.node-title {
  font-size: 11px;
  font-weight: 700;
  fill: #FFFFFF;
}

.node-subtitle {
  font-size: 9.5px;
  font-family: var(--font-mono);
  fill: #94A3B8;
}

.node-badge {
  font-size: 8.5px;
  font-weight: 700;
  text-transform: uppercase;
}

.node-badge.active-bg {
  fill: var(--status-active);
}

.node-badge.passive-bg {
  fill: var(--status-passive);
}

/* Architecture Lines */
.arch-link {
  fill: none;
  stroke: #475569;
  stroke-width: 2;
  transition: all 0.3s ease;
}

.arch-link.ha-link {
  stroke: #FA582D;
  stroke-width: 2.5;
  stroke-dasharray: 4 4;
}

.arch-link.peering-link {
  stroke: #38BDF8;
  stroke-width: 2.5;
  stroke-dasharray: 6 6;
}

.arch-link.flow-active {
  stroke-width: 3.5;
  stroke-linecap: round;
}

/* Animated Particles */
.flow-particle {
  pointer-events: none;
}

/* Collapsed summary card */
.collapsed-card {
  fill: #1E293B;
  stroke: #475569;
  stroke-width: 1.5;
  rx: 12;
  cursor: pointer;
}

.collapsed-card:hover {
  stroke: var(--panw-orange);
}

/* Fix SVG Icon Sizing */
.node-icon svg {
  width: 32px;
  height: 32px;
  max-width: 32px;
  max-height: 32px;
  display: block;
}

.drawer-icon svg {
  width: 36px;
  height: 36px;
  max-width: 36px;
  max-height: 36px;
  display: block;
}

/* Cluster Overview & Toggle Buttons */
.cluster-overview-card {
  fill: rgba(30, 41, 59, 0.7);
  stroke: var(--panw-orange);
  stroke-width: 1.5;
  rx: 10;
  transition: all 0.2s ease;
  cursor: pointer;
}

.cluster-overview-card:hover {
  fill: rgba(30, 41, 59, 0.95);
  filter: drop-shadow(0 0 12px var(--panw-orange-glow));
}

.btn-container-toggle {
  cursor: pointer;
  transition: all 0.2s ease;
}

.btn-container-toggle:hover rect {
  fill: var(--panw-orange);
}

.btn-container-toggle:hover text {
  fill: #FFFFFF;
}

/* ==========================================================================
   Overlay/canvas collision fixes
   --------------------------------------------------------------------------
   .left-panel (360px) and .right-drawer (420px) are absolutely-positioned
   overlays sitting ON TOP of a full-bleed .diagram-viewport, and the drawer
   (z-60) also covers the LEVEL bar (z-50). So opening either one hid diagram
   content behind it, and opening the drawer hid the level switcher entirely.

   Fix: inset the canvas by whatever is currently open, and slide the two
   right-hand control clusters clear of the drawer. The SVG keeps a fixed
   viewBox with preserveAspectRatio, so narrowing its box simply rescales the
   drawing into the space that is actually visible instead of hiding its edges.
   ========================================================================== */

.diagram-viewport {
  transition: left 0.3s cubic-bezier(0.16, 1, 0.3, 1),
              right 0.3s cubic-bezier(0.16, 1, 0.3, 1);
}

/* :has() lets a parent react to descendant state; supported by every browser
   this app already targets. Anything older just keeps the previous behaviour. */
.app-container:has(.left-panel:not(.collapsed)) .diagram-viewport {
  left: 396px;
  width: auto;
  right: 0;
}

.app-container:has(.right-drawer.open) .diagram-viewport {
  right: 456px;
  width: auto;
}

.app-container:has(.left-panel:not(.collapsed)):has(.right-drawer.open) .diagram-viewport {
  left: 396px;
  right: 456px;
  width: auto;
}

/* Keep the LEVEL bar and the zoom cluster out from under the drawer. */
.quick-nav-bar,
.viewport-controls {
  transition: right 0.3s cubic-bezier(0.16, 1, 0.3, 1);
}

.app-container:has(.right-drawer.open) .quick-nav-bar,
.app-container:has(.right-drawer.open) .viewport-controls {
  right: 456px;
}

/* The drawer is taller than the level bar; on short viewports let it scroll
   rather than push its footer off-screen. */
.right-drawer,
.left-panel {
  max-height: calc(100vh - 140px);
}