.site-header {
  position: relative;
  z-index: 20;
  flex: none;
  border-bottom: 1px solid var(--color-border);
  background: var(--color-canvas);
}

.site-header-row {
  min-height: var(--header-h);
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: var(--space-5);
  padding: 0 28px;
}

.brand-lockup {
  min-width: 0;
  display: flex;
  align-items: baseline;
  gap: 20px;
  white-space: nowrap;
}

.brand-name {
  font-size: clamp(34px, 3.2vw, 52px);
  font-weight: 700;
  line-height: 1;
  letter-spacing: -0.05em;
}

.brand-description {
  overflow: hidden;
  color: var(--color-text-muted);
  font-family: var(--font-technical);
  font-size: clamp(13px, 1.35vw, 20px);
  letter-spacing: 0.19em;
  text-overflow: ellipsis;
}

.header-nav {
  display: flex;
  align-items: center;
  gap: 32px;
  font-size: clamp(18px, 1.65vw, 26px);
  white-space: nowrap;
}

#main {
  flex: 1;
  min-height: 0;
  display: grid;
  grid-template-columns: var(--panel-w) minmax(0, 1fr);
  background: var(--color-canvas);
}

#ui-panel {
  min-width: 0;
  overflow-y: auto;
  overscroll-behavior: contain;
  padding: 24px 22px 32px;
  border-right: 1px solid var(--color-border);
  background: var(--color-canvas);
  scrollbar-color: var(--color-border-strong) transparent;
  scrollbar-width: thin;
}

.workspace {
  min-width: 0;
  min-height: 0;
  display: grid;
  grid-template-rows: minmax(0, 1fr) var(--toolbar-h);
}

#canvas-container {
  position: relative;
  min-width: 0;
  min-height: 0;
  display: flex;
  align-items: center;
  justify-content: center;
  overflow: hidden;
  background: var(--color-canvas);
}

#canvas-container > svg {
  width: 100%;
  height: 100%;
  background: var(--color-canvas);
}

#three-container {
  position: absolute;
  inset: 0;
  display: flex;
  align-items: stretch;
  justify-content: stretch;
  z-index: 0;
}

#three-container[hidden] {
  display: none !important;
}

.simulation-status {
  position: absolute;
  left: 50%;
  bottom: 24px;
  z-index: 5;
  max-width: calc(100% - 48px);
  transform: translateX(-50%);
  color: var(--color-text-muted);
  font-family: var(--font-technical);
  font-size: clamp(13px, 1.25vw, 18px);
  letter-spacing: 0.1em;
  text-align: center;
  white-space: nowrap;
  pointer-events: none;
}

.simulation-toolbar {
  min-width: 0;
  min-height: var(--toolbar-h);
  display: grid;
  grid-template-columns: auto auto minmax(190px, auto) auto;
  align-items: center;
  justify-content: space-between;
  gap: clamp(16px, 3vw, 56px);
  padding: 10px clamp(24px, 4vw, 72px);
  border-top: 1px solid var(--color-border);
  background: var(--color-canvas);
}

.toolbar-group {
  display: flex;
  align-items: center;
}

.transport-controls {
  gap: 14px;
}

.speed-controls {
  gap: 12px;
}

/* Mobile overlays keep the existing compact mode working. */
#mobile-toolbar {
  position: absolute;
  top: env(safe-area-inset-top, 8px);
  left: env(safe-area-inset-left, 8px);
  right: env(safe-area-inset-right, 8px);
  z-index: 10;
  display: none;
  align-items: center;
  gap: 8px;
  padding: 8px;
  border: 1px solid var(--color-border);
  border-radius: var(--radius-medium);
  background: rgba(0, 0, 0, 0.86);
  backdrop-filter: blur(8px);
}

#rules-overlay {
  position: absolute;
  left: env(safe-area-inset-left, 8px);
  right: env(safe-area-inset-right, 8px);
  top: calc(env(safe-area-inset-top, 8px) + 58px);
  z-index: 9;
  display: none;
  max-width: 540px;
  max-height: 96px;
  align-items: center;
  justify-content: flex-start;
  flex-wrap: wrap;
  gap: 6px;
  padding: 8px;
  overflow-x: auto;
  overflow-y: hidden;
  border-radius: var(--radius-medium);
  background: rgba(0, 0, 0, 0.72);
}

#node-inspector-overlay {
  position: absolute;
  right: 12px;
  bottom: 12px;
  z-index: 8;
  max-width: min(420px, 65vw);
  padding: 8px 10px;
  border-radius: var(--radius-medium);
  background: rgba(0, 0, 0, 0.5);
  color: var(--color-text-subtle);
  font-family: var(--font-technical);
  font-size: 12px;
  line-height: 1.25;
  white-space: pre-line;
  pointer-events: none;
}

@media (max-width: 1100px) {
  .simulation-toolbar {
    grid-template-columns: auto auto auto auto;
    gap: 12px;
    padding-inline: 18px;
  }
}

@media (max-width: 980px) {
  .site-header {
    padding-inline: 0;
  }

  .site-header-row {
    padding-inline: 18px;
  }

  .brand-description {
    display: none;
  }
}

body.mobile-basic .site-header,
body.mobile-basic #ui-panel,
body.mobile-basic .simulation-toolbar {
  display: none;
}

body.mobile-basic #main {
  display: block;
}

body.mobile-basic .workspace {
  width: 100%;
  height: 100%;
  display: block;
}

body.mobile-basic #canvas-container {
  width: 100%;
  height: 100%;
}

body.mobile-basic #mobile-toolbar,
body.mobile-basic #rules-overlay {
  display: flex;
}

body.mobile-basic #node-inspector-overlay {
  right: env(safe-area-inset-right, 8px);
  bottom: env(safe-area-inset-bottom, 8px);
}