body.backstage-preview-split {
  --layout-sidebar: 18vw;
  --layout-form: 58vw;
  --layout-preview: 24vw;
}

body.backstage-preview-expanded {
  overflow: hidden;
}

.backstage-split-layout {
  display: flex;
  gap: 1rem;
  align-items: flex-start;
}

.backstage-split-form {
  flex: 1 1 0;
  min-width: min(100%, 22rem);
  max-width: var(--layout-form);
}

.backstage-split-preview {
  flex: 0 0 var(--layout-preview);
  max-width: var(--layout-preview);
  width: var(--layout-preview);
  position: sticky;
  top: 1rem;
  align-self: flex-start;
  display: flex;
  flex-direction: column;
  gap: 0;
  max-height: calc(100dvh - 2rem);
  height: auto;
  padding: 0.75rem;
  overflow: hidden;
  background: var(--card);
  border: 1px solid var(--border);
  border-radius: var(--border-radius, 8px);
}

.backstage-preview-toolbar {
  margin: -0.75rem -0.75rem 0;
  border: 0;
  border-bottom: 1px solid var(--border);
  border-radius: var(--border-radius, 8px) var(--border-radius, 8px) 0 0;
  overflow: hidden;
}

.backstage-preview-chrome {
  display: flex;
  flex-wrap: nowrap;
  align-items: center;
  gap: 0.5rem;
  min-width: 0;
  padding: 0.4rem 0.65rem;
  background: color-mix(in oklab, var(--color-base-100) 45%, transparent);
}

.dark .backstage-preview-chrome {
  background: color-mix(in oklab, var(--color-base-900) 45%, transparent);
}

.backstage-preview-chrome-dots {
  display: inline-flex;
  align-items: center;
  gap: 0.3rem;
  flex-shrink: 0;
}

.backstage-preview-chrome-dots span {
  width: 0.5rem;
  height: 0.5rem;
  border-radius: 999px;
  background: color-mix(in oklab, var(--color-base-400) 55%, transparent);
}

.backstage-preview-chrome-dots span:nth-child(1) {
  background: rgb(239 68 68 / 0.55);
}

.backstage-preview-chrome-dots span:nth-child(2) {
  background: rgb(234 179 8 / 0.55);
}

.backstage-preview-chrome-dots span:nth-child(3) {
  background: rgb(34 197 94 / 0.55);
}

.backstage-preview-chrome-labels {
  display: flex;
  align-items: baseline;
  gap: 0.35rem;
  min-width: 0;
  flex: 1 1 auto;
  overflow: hidden;
}

.backstage-preview-chrome-labels .backstage-preview-note::before {
  content: "·";
  margin-right: 0.35rem;
  color: var(--color-base-400);
}

.backstage-preview-title {
  font-weight: 600;
  font-size: 0.75rem;
  color: var(--color-base-900);
  white-space: nowrap;
}

.dark .backstage-preview-title {
  color: var(--color-base-100);
}

.backstage-preview-note {
  font-size: 0.75rem;
  color: var(--color-base-500);
  white-space: nowrap;
}

.backstage-preview-actions {
  display: flex;
  flex-wrap: nowrap;
  align-items: center;
  gap: 0.25rem;
  flex-shrink: 0;
  margin-left: auto;
}

.backstage-preview-btn {
  display: inline-flex;
  align-items: center;
  gap: 0.25rem;
  font-size: 0.75rem;
  line-height: 1;
  padding: 0.4rem 0.65rem;
  border-radius: calc(var(--border-radius, 8px) - 2px);
  border: 1px solid transparent;
  background: transparent;
  color: var(--color-base-600);
  cursor: pointer;
  transition: background 0.15s ease, color 0.15s ease, border-color 0.15s ease;
}

.backstage-preview-btn .material-symbols-outlined {
  font-size: 1rem;
  line-height: 1;
}

.backstage-preview-btn--icon {
  width: 1.75rem;
  height: 1.75rem;
  padding: 0;
  justify-content: center;
  flex-shrink: 0;
}

.backstage-preview-btn--icon .material-symbols-outlined {
  font-size: 1.125rem;
}

.dark .backstage-preview-btn {
  background: transparent;
  color: var(--color-base-300);
}

.backstage-preview-btn:hover,
.backstage-preview-refresh:hover {
  background: rgb(var(--color-primary-500) / 0.1);
  color: rgb(var(--color-primary-600) / 1);
}

.backstage-preview-btn.is-active {
  font-weight: 600;
  border-color: var(--border);
  background: var(--card);
  color: rgb(var(--color-primary-600) / 1);
}

.dark .backstage-preview-btn.is-active {
  border-color: var(--border);
  background: var(--card);
  color: rgb(var(--color-primary-400) / 1);
}

.backstage-preview-frame-host {
  display: flex;
  flex-direction: column;
  min-height: 0;
}

.backstage-split-preview .backstage-preview-frame-host {
  padding-top: 0.75rem;
}

/* Desktop: 16:9 landscape frame, iframe rendered at 1280×720 and scaled down */
.backstage-preview-frame-wrap.is-desktop {
  flex: 0 0 auto;
  width: 100%;
  aspect-ratio: 16 / 9;
  overflow: hidden;
  border: 1px solid var(--border);
  border-radius: var(--border-radius, 8px);
  background: color-mix(in oklab, var(--color-base-100) 50%, transparent);
}

.dark .backstage-preview-frame-wrap.is-desktop {
  background: color-mix(in oklab, var(--color-base-950) 50%, transparent);
}

.backstage-preview-frame-wrap.is-desktop .backstage-preview-scaler {
  width: 1280px;
  height: 720px;
  transform-origin: top left;
}

.backstage-preview-frame-wrap.is-desktop .backstage-preview-iframe {
  width: 1280px;
  height: 720px;
  border: 0;
  background: white;
}

/* Tablet: portrait frame, iframe rendered at 768×1024 and scaled down */
.backstage-preview-frame-wrap.is-tablet {
  flex: 0 0 auto;
  width: 100%;
  max-width: 768px;
  aspect-ratio: 768 / 1024;
  margin-inline: auto;
  overflow: hidden;
  border: 1px solid var(--border);
  border-radius: var(--border-radius, 8px);
  background: color-mix(in oklab, var(--color-base-100) 50%, transparent);
}

.dark .backstage-preview-frame-wrap.is-tablet {
  background: color-mix(in oklab, var(--color-base-950) 50%, transparent);
}

.backstage-preview-frame-wrap.is-tablet .backstage-preview-scaler {
  width: 768px;
  height: 1024px;
  transform-origin: top left;
}

.backstage-preview-frame-wrap.is-tablet .backstage-preview-iframe {
  width: 768px;
  height: 1024px;
  border: 0;
  background: white;
}

/* Mobile: narrow portrait frame */
.backstage-preview-frame-wrap.is-mobile {
  flex: 0 0 auto;
  max-width: 390px;
  width: 100%;
  aspect-ratio: 9 / 16;
  margin-inline: auto;
  overflow: hidden;
  border: 1px solid var(--border);
  border-radius: var(--border-radius, 8px);
  background: color-mix(in oklab, var(--color-base-100) 50%, transparent);
}

.dark .backstage-preview-frame-wrap.is-mobile {
  background: color-mix(in oklab, var(--color-base-950) 50%, transparent);
}

.backstage-preview-frame-wrap.is-mobile .backstage-preview-scaler {
  width: 100%;
  height: 100%;
  transform: none;
}

.backstage-preview-frame-wrap.is-mobile .backstage-preview-iframe {
  width: 100%;
  height: 100%;
  border: 0;
  background: white;
}

/* Responsive: DevTools-style draggable viewport */
.backstage-preview-frame-wrap.is-responsive {
  position: relative;
  flex: 0 0 auto;
  width: 100%;
  min-height: 12rem;
  aspect-ratio: 16 / 9;
  overflow: hidden;
  border: 1px solid var(--border);
  border-radius: var(--border-radius, 8px);
  background: color-mix(in oklab, var(--color-base-100) 50%, transparent);
}

.dark .backstage-preview-frame-wrap.is-responsive {
  background: color-mix(in oklab, var(--color-base-950) 50%, transparent);
}

.backstage-preview-frame-wrap.is-responsive .backstage-preview-scaler {
  transform-origin: top left;
}

.backstage-preview-frame-wrap.is-responsive .backstage-preview-iframe {
  border: 0;
  background: white;
}

.backstage-preview-size-label {
  position: absolute;
  top: 0.5rem;
  left: 50%;
  transform: translateX(-50%);
  z-index: 2;
  font-size: 0.6875rem;
  padding: 0.15rem 0.5rem;
  border: 1px solid var(--border);
  border-radius: calc(var(--border-radius, 8px) - 2px);
  background: var(--card, rgb(255 255 255));
  color: var(--color-base-600);
  pointer-events: none;
  white-space: nowrap;
}

.dark .backstage-preview-size-label {
  background: var(--card);
  color: var(--color-base-300);
}

.backstage-preview-frame-wrap:not(.is-responsive) .backstage-preview-size-label,
.backstage-preview-frame-wrap:not(.is-responsive) .backstage-preview-resize-handle {
  display: none;
}

.backstage-preview-resize-handle {
  position: absolute;
  z-index: 3;
}

.backstage-preview-resize-handle.is-east {
  right: 0;
  top: 0;
  bottom: 0;
  width: 8px;
  cursor: ew-resize;
}

.backstage-preview-resize-handle.is-south {
  left: 0;
  right: 0;
  bottom: 0;
  height: 8px;
  cursor: ns-resize;
}

.backstage-preview-resize-handle.is-southeast {
  right: 0;
  bottom: 0;
  width: 14px;
  height: 14px;
  cursor: nwse-resize;
}

body.backstage-preview-resizing {
  user-select: none;
}

/* Fullscreen expand overlay */
.backstage-preview-overlay {
  position: fixed;
  inset: 0;
  z-index: 60;
}

.backstage-preview-overlay[hidden] {
  display: none;
}

.backstage-preview-overlay-backdrop {
  position: fixed;
  inset: 0;
  z-index: 60;
  backdrop-filter: blur(2px);
  background: color-mix(in oklab, var(--color-base-900) 20%, transparent);
}

.dark .backstage-preview-overlay-backdrop {
  background: color-mix(in oklab, var(--color-base-900) 80%, transparent);
}

.backstage-preview-overlay-panel {
  position: fixed;
  inset: 1rem;
  z-index: 70;
  display: flex;
  flex-direction: column;
  gap: 0;
  padding: 0;
  border: 1px solid var(--border);
  border-radius: var(--border-radius, 8px);
  background: var(--card, rgb(255 255 255));
  box-shadow: none;
  overflow: hidden;
}

.backstage-preview-overlay-panel .backstage-preview-toolbar {
  margin: 0;
  flex-shrink: 0;
}

.dark .backstage-preview-overlay-panel {
  background: var(--card);
}

/* Expanded preview — solid surfaces in dark mode (no frosted glass) */
.dark body.backstage-preview-expanded .backstage-preview-overlay-backdrop {
  backdrop-filter: none;
  -webkit-backdrop-filter: none;
  background: var(--color-base-950);
}

.dark body.backstage-preview-expanded .backstage-preview-overlay-panel .backstage-preview-chrome {
  background: var(--color-base-900);
}

.dark body.backstage-preview-expanded .backstage-preview-overlay-panel .backstage-preview-frame-host {
  background: var(--color-base-900);
}

.dark body.backstage-preview-expanded .backstage-preview-overlay-panel .backstage-preview-frame-wrap.is-desktop,
.dark body.backstage-preview-expanded .backstage-preview-overlay-panel .backstage-preview-frame-wrap.is-tablet,
.dark body.backstage-preview-expanded .backstage-preview-overlay-panel .backstage-preview-frame-wrap.is-mobile,
.dark body.backstage-preview-expanded .backstage-preview-overlay-panel .backstage-preview-frame-wrap.is-responsive {
  background: var(--color-base-800);
}

.backstage-preview-overlay-panel .backstage-preview-frame-host {
  display: flex;
  align-items: center;
  justify-content: center;
  flex: 1 1 auto;
  min-height: 0;
}

.backstage-preview-overlay-panel .backstage-preview-frame-wrap.is-desktop,
.backstage-preview-overlay-panel .backstage-preview-frame-wrap.is-tablet {
  width: 100%;
  max-width: 100%;
  flex: 1 1 auto;
  aspect-ratio: auto;
  min-height: 0;
  height: 100%;
}

.backstage-preview-overlay-panel .backstage-preview-frame-wrap.is-responsive {
  width: auto;
  height: auto;
  flex: 0 0 auto;
  max-width: none;
  min-height: 0;
  aspect-ratio: auto;
}

.backstage-split-preview.is-collapsed .backstage-preview-frame-host {
  min-height: 12rem;
}

/* Match uniform border token when split preview is active */
.backstage-preview-split .backstage-split-form fieldset {
  border-color: var(--border);
}

.dark .backstage-preview-split .backstage-split-form fieldset {
  border-color: var(--border);
}

@media (max-width: 1023px) {
  .backstage-split-layout {
    flex-direction: column;
  }

  .backstage-split-form {
    max-width: none;
  }

  .backstage-split-preview {
    position: static;
    flex: 1 1 auto;
    max-width: 100%;
    width: 100%;
    max-height: none;
    height: auto;
    padding-left: 0;
    border-left: 0;
    padding-top: 1.5rem;
    border-top: 1px solid var(--border);
  }

  .dark .backstage-split-preview {
    border-top-color: var(--border);
  }

  .backstage-preview-overlay-panel {
    inset: 0;
    border-radius: 0;
    border-left: 0;
    border-right: 0;
    border-bottom: 0;
  }
}

.backstage-preview-error {
  margin: 0.75rem;
  padding: 0.75rem 1rem;
  border-radius: var(--border-radius, 8px);
  border: 1px solid var(--border);
  background: var(--muted);
  color: var(--foreground);
  font-size: 0.8125rem;
  line-height: 1.45;
}