/**
* CSP-friendly style injection.
*
* All static viewer CSS lives here as a single string. It is attached
* either via `adoptedStyleSheets` (constructable stylesheet — no CSP
* implications at all) or, when that API is unavailable, via a
* `<style>` element stamped with the caller-supplied nonce.
*
* Runtime values (current transform, opacity, slot aspect ratio…) are
* written as CSS custom properties on individual elements via
* `element.style.setProperty("--pc-*", …)`, which only requires
* `style-src-attr` and is compatible with strict CSP.
*
* See README "Content Security Policy cookbook" for the matching
* header configuration.
*/
export declare const PC_STYLES = "\n/* Typed custom properties — enables CSS transitions on these values\n * and gives the browser type information for optimised interpolation.\n * Baseline since July 2024. */\n@property --pc-root-opacity {\n  syntax: \"<number>\";\n  inherits: false;\n  initial-value: 1;\n}\n@property --pc-bg {\n  syntax: \"<color>\";\n  inherits: true;\n  initial-value: rgba(0, 0, 0, 0.92);\n}\n@property --pc-fg {\n  syntax: \"<color>\";\n  inherits: true;\n  initial-value: #fff;\n}\n@property --pc-focus {\n  syntax: \"<color>\";\n  inherits: true;\n  initial-value: #7dd3fc;\n}\n.pc-root {\n  position: fixed;\n  inset: 0;\n  z-index: 99999;\n  display: none;\n  flex-direction: column;\n  align-items: center;\n  justify-content: center;\n  background: var(--pc-bg, rgba(0, 0, 0, 0.92));\n  color: var(--pc-fg, #fff);\n  font-family: var(--pc-font, system-ui, sans-serif);\n  margin: 0;\n  padding: 0;\n  border: 0;\n  max-width: none;\n  max-height: none;\n  width: 100%;\n  height: 100%;\n  opacity: var(--pc-root-opacity, 1);\n}\n.pc-root[open],\n.pc-root.pc-root--open {\n  display: flex;\n  animation: pc-root-in 200ms ease-out;\n}\n/* Close animation is driven by WAAPI (element.animate) — no CSS\n * keyframe needed. The class is kept for backwards compatibility\n * with any consumer CSS that targets it. */\n.pc-root.pc-root--closing {\n  display: flex;\n}\n/* Native <dialog>'s ::backdrop defaults to transparent, so the\n * 0.92 root background would leak page content through. Force\n * the ::backdrop fully opaque with the same custom property the\n * root uses. iOS Safari ignores ::backdrop on <dialog> entirely\n * but still honors the .pc-root background, so both paths stay\n * consistent. */\n.pc-root::backdrop {\n  background: var(--pc-bg, rgba(0, 0, 0, 0.96));\n}\n.pc-root[open][open]::backdrop,\n.pc-root.pc-root--open::backdrop {\n  animation: pc-root-in 200ms ease-out;\n}\n.pc-root.pc-root--closing::backdrop {\n  opacity: 0;\n}\n@keyframes pc-root-in {\n  from { opacity: 0; }\n  to   { opacity: 1; }\n}\n/* pc-root-out removed — close animation is WAAPI-driven. */\n@media (prefers-reduced-motion: reduce) {\n  .pc-root[open],\n  .pc-root.pc-root--open {\n    animation: none !important;\n  }\n}\n/* iOS faux-fullscreen (#14). Overrides any parent transform so the\n * viewer covers the visual viewport, and bumps z-index above any\n * page chrome or sticky headers. */\n.pc-root.pc-root--faux-fullscreen {\n  position: fixed;\n  inset: 0;\n  width: 100vw;\n  height: 100dvh;\n  z-index: 2147483647;\n  transform: none !important;\n}\n.pc-stage {\n  position: relative;\n  flex: 1 1 auto;\n  width: 100%;\n  display: flex;\n  align-items: center;\n  justify-content: center;\n  overflow: hidden;\n  touch-action: none;\n}\n.pc-slot {\n  position: relative;\n  display: flex;\n  align-items: center;\n  justify-content: center;\n  aspect-ratio: var(--pc-slot-ar, auto);\n}\n/* ThumbHash / BlurHash placeholder background while the full-res\n * image decodes (#29). The consumer supplies any CSS background\n * value via the --pc-slot-placeholder custom property; pencere\n * mounts it here and strips the class one rAF after the real\n * image lands. */\n.pc-slot.pc-slot--placeholder {\n  background: var(--pc-slot-placeholder, #0000);\n  background-size: cover;\n  background-position: center;\n  transition: opacity 160ms ease-out;\n}\n.pc-img {\n  max-width: 100%;\n  max-height: 100%;\n  user-select: none;\n  -webkit-user-drag: none;\n  transform-origin: center center;\n  /* will-change is managed dynamically by the viewer on gesture\n     start/end to avoid keeping a compositor layer alive forever (#34). */\n  transform: var(--pc-img-transform, none);\n}\n.pc-toolbar-top,\n.pc-toolbar-bottom {\n  position: absolute;\n  inset-inline: 0;\n  display: flex;\n  align-items: center;\n  pointer-events: none;\n  z-index: 2;\n}\n.pc-toolbar-top {\n  top: 0;\n  justify-content: space-between;\n  padding: 0.75rem 1rem;\n  gap: 1rem;\n  background: linear-gradient(to bottom, color-mix(in srgb, var(--pc-bg) 60%, transparent), transparent);\n}\n.pc-toolbar-bottom {\n  bottom: 0;\n  justify-content: center;\n  padding: 1rem 1.5rem 1.25rem;\n  background: linear-gradient(to top, color-mix(in srgb, var(--pc-bg) 60%, transparent), transparent);\n}\n.pc-caption {\n  margin: 0 auto;\n  max-width: 90ch;\n  text-align: center;\n  line-height: 1.4;\n  font-size: 0.95rem;\n  /*\n   * CJK-aware line breaking (#61). overflow-wrap: anywhere ensures\n   * very long Latin tokens wrap; line-break: strict pulls Japanese\n   * and Chinese break rules in line with print typography\n   * conventions; word-break: normal stays out of the way for\n   * mixed-script content.\n   */\n  word-break: normal;\n  overflow-wrap: anywhere;\n  line-break: strict;\n}\n/* Korean convention is to avoid breaking inside eojeol (word units). */\n.pc-caption[lang=\"ko\"],\n.pc-caption[lang^=\"ko-\"] {\n  word-break: keep-all;\n}\n/*\n * Script-specific font stacks (#65). Consumers override these custom\n * properties in their host CSS to plug in \"Noto Sans JP\", \"Noto Naskh\n * Arabic\", etc. without patching pencere's stylesheet.\n */\n.pc-caption[lang=\"ja\"],\n.pc-caption[lang^=\"ja-\"],\n.pc-longdesc[lang=\"ja\"],\n.pc-longdesc[lang^=\"ja-\"] {\n  font-family: var(--pc-font-cjk-ja, var(--pc-font, inherit));\n}\n.pc-caption[lang=\"ko\"],\n.pc-caption[lang^=\"ko-\"],\n.pc-longdesc[lang=\"ko\"],\n.pc-longdesc[lang^=\"ko-\"] {\n  font-family: var(--pc-font-cjk-ko, var(--pc-font, inherit));\n}\n.pc-caption[lang=\"zh-Hans\"],\n.pc-caption[lang=\"zh-CN\"],\n.pc-caption[lang=\"zh-SG\"],\n.pc-longdesc[lang=\"zh-Hans\"],\n.pc-longdesc[lang=\"zh-CN\"],\n.pc-longdesc[lang=\"zh-SG\"] {\n  font-family: var(--pc-font-cjk-zh-hans, var(--pc-font, inherit));\n}\n.pc-caption[lang=\"zh-Hant\"],\n.pc-caption[lang=\"zh-TW\"],\n.pc-caption[lang=\"zh-HK\"],\n.pc-longdesc[lang=\"zh-Hant\"],\n.pc-longdesc[lang=\"zh-TW\"],\n.pc-longdesc[lang=\"zh-HK\"] {\n  font-family: var(--pc-font-cjk-zh-hant, var(--pc-font, inherit));\n}\n.pc-caption[lang=\"ar\"],\n.pc-caption[lang^=\"ar-\"],\n.pc-caption[lang=\"he\"],\n.pc-caption[lang^=\"he-\"],\n.pc-longdesc[lang=\"ar\"],\n.pc-longdesc[lang^=\"ar-\"],\n.pc-longdesc[lang=\"he\"],\n.pc-longdesc[lang^=\"he-\"] {\n  font-family: var(--pc-font-arabic, var(--pc-font, inherit));\n}\n.pc-counter {\n  font-size: 0.85rem;\n  opacity: 0.85;\n  letter-spacing: 0.02em;\n}\n.pc-btn {\n  min-width: 44px;\n  min-height: 44px;\n  padding: 0;\n  background: transparent;\n  color: inherit;\n  border: 0;\n  cursor: pointer;\n  font: inherit;\n  pointer-events: auto;\n  /* Center the glyph — both horizontally and vertically. Without\n   * explicit flex centering the default button layout leaves the\n   * chevrons/× drifting left on tall line-heights and glyph-rich\n   * fonts. line-height:1 kills the extra baseline gap. */\n  display: inline-flex;\n  align-items: center;\n  justify-content: center;\n  line-height: 1;\n  text-align: center;\n  /*\n   * WCAG 2.4.11 Focus Not Obscured — when the browser scrolls a\n   * focused button into view, leave at least 80px of headroom under\n   * the top toolbar band and above the bottom caption band so the\n   * focus ring never tucks behind a gradient edge.\n   */\n  scroll-margin-block: 80px;\n}\n.pc-btn:focus-visible {\n  outline: 2px solid var(--pc-focus, #7dd3fc);\n  outline-offset: 2px;\n  border-radius: 6px;\n}\n.pc-btn--close {\n  font-size: 1.75rem;\n}\n.pc-btn--nav {\n  position: absolute;\n  /* Vertically center via top:0/bottom:0 + margin:auto. More robust\n   * than top:50%+translateY(-50%) which can drift when the stage\n   * has a pending transform from the slide-in animation. */\n  top: 0;\n  bottom: 0;\n  margin-block: auto;\n  font-size: 2rem;\n  width: 48px;\n  height: 48px;\n  border-radius: 999px;\n  background: color-mix(in srgb, var(--pc-bg) 50%, transparent);\n  backdrop-filter: blur(8px);\n  -webkit-backdrop-filter: blur(8px);\n}\n.pc-btn--prev {\n  inset-inline-start: 0.75rem;\n}\n.pc-btn--next {\n  inset-inline-end: 0.75rem;\n}\n.pc-btn[disabled] {\n  opacity: 0.35;\n  cursor: not-allowed;\n}\n.pc-live {\n  position: absolute;\n  width: 1px;\n  height: 1px;\n  margin: -1px;\n  padding: 0;\n  overflow: hidden;\n  clip: rect(0 0 0 0);\n  white-space: nowrap;\n  border: 0;\n}\n@media (prefers-reduced-motion: reduce) {\n  .pc-img {\n    transition: none !important;\n  }\n}\n@media (max-width: 640px) {\n  /*\n   * Narrow viewport tuning. Keeps the 44x44 hit targets for\n   * WCAG 2.5.5 while tightening padding so captions, counter,\n   * and nav chevrons don't steal image space on phones.\n   */\n  .pc-toolbar-top {\n    padding: 0.5rem 0.75rem;\n  }\n  .pc-toolbar-bottom {\n    padding: 0.75rem 1rem 1rem;\n  }\n  .pc-btn--nav {\n    width: 44px;\n    height: 44px;\n    font-size: 1.6rem;\n  }\n  .pc-btn--prev {\n    inset-inline-start: 0.4rem;\n  }\n  .pc-btn--next {\n    inset-inline-end: 0.4rem;\n  }\n  .pc-btn--close {\n    font-size: 1.5rem;\n  }\n  .pc-counter {\n    font-size: 0.8rem;\n  }\n  .pc-caption {\n    font-size: 0.85rem;\n    max-width: none;\n  }\n}\n@media (forced-colors: active) {\n  /*\n   * Windows High Contrast / forced-colors mode strips author colors\n   * and backgrounds. Map pencere's chrome to the standard system\n   * color keywords so controls stay visible and focusable without\n   * relying on gradient backdrops or rgba fills.\n   */\n  .pc-root {\n    background: Canvas;\n    color: CanvasText;\n    forced-color-adjust: none;\n  }\n  .pc-toolbar-top,\n  .pc-toolbar-bottom {\n    /* Gradients become flat white in forced-colors; drop them. */\n    background: transparent;\n  }\n  .pc-btn {\n    background: ButtonFace;\n    color: ButtonText;\n    border: 1px solid ButtonText;\n  }\n  .pc-btn:focus-visible {\n    outline: 2px solid Highlight;\n    outline-offset: 2px;\n  }\n  .pc-btn[disabled] {\n    color: GrayText;\n    border-color: GrayText;\n  }\n  .pc-btn--nav {\n    background: ButtonFace;\n  }\n  .pc-counter,\n  .pc-caption {\n    color: CanvasText;\n  }\n}\n";
/**
* Ensure the static pencere stylesheet is attached to the given
* document/shadow root. Idempotent: repeated calls on the same root
* are no-ops.
*
* @param root  Document or ShadowRoot whose stylesheet set receives
*              the rules. For a regular document, the light tree.
* @param nonce Optional CSP nonce. Applied only when falling back to
*              a `<style>` element (adoptedStyleSheets does not need
*              a nonce because it has no inline representation).
*/
export declare function injectStyles(root: Document | ShadowRoot, nonce?: string): void;
/** Visible for testing. */
export declare function _resetStyleRegistry(): void;