:root {
  color-scheme: light;
  --brand: #0d657d;
  --brand-dark: #084d60;
  --surface: #fff;
  --canvas-bg: #dfe4e8;
  --ink: #1a2534;
  --muted: #5f6c7c;
  --line: #ccd4dc;
  --shadow: 0 14px 38px rgba(20, 34, 48, .18);
  --swipe-edge-glow: rgba(13, 101, 125, .3);
}

:root[data-theme="dark"] {
  color-scheme: dark;
  --brand: #69bfd1;
  --brand-dark: #8ed0dd;
  --surface: #111a28;
  --canvas-bg: #07111a;
  --ink: #edf2f7;
  --muted: #aab6c6;
  --line: #344154;
  --shadow: 0 14px 38px rgba(0, 0, 0, .42);
  --swipe-edge-glow: rgba(105, 191, 209, .32);
}

* { box-sizing: border-box; }
html, body { min-height: 100%; }
body { margin: 0; color: var(--ink); background: var(--canvas-bg); font: 15px/1.45 system-ui, -apple-system, "Segoe UI", sans-serif; }
button, input, a { font: inherit; }
button, a { -webkit-tap-highlight-color: transparent; }

.viewer-header { min-height: 72px; padding: 10px max(16px, env(safe-area-inset-left)) 10px max(16px, env(safe-area-inset-right)); display: grid; grid-template-columns: auto minmax(0, 1fr) auto; align-items: center; gap: 13px; color: #fff; background: #0d3b4c; }
.publisher-logo { display: grid; place-items: center; }
.publisher-logo img { display: block; object-fit: contain; }
.viewer-brand { min-width: 0; display: grid; }
.viewer-brand a { color: #fff; font: 700 clamp(16px, 2.5vw, 21px)/1.15 Georgia, "Times New Roman", serif; text-decoration: none; }
.viewer-brand span { margin-top: 3px; color: #c9dbe1; font-size: 11px; letter-spacing: .055em; }
.viewer-preferences { display: flex; align-items: center; gap: 8px; }
.icon-button, .language-switch button { min-height: 36px; border: 1px solid rgba(255, 255, 255, .34); color: #fff; background: transparent; }
.icon-button { width: 36px; border-radius: 50%; }
.language-switch { display: flex; }
.language-switch button { min-width: 38px; padding: 5px 8px; }
.language-switch button:first-child { border-radius: 7px 0 0 7px; }
.language-switch button:last-child { border-radius: 0 7px 7px 0; }
.language-switch button + button { border-left: 0; }
.language-switch button[aria-pressed="true"] { color: #0d3b4c; background: #fff; }

.viewer-toolbar { position: sticky; top: 0; z-index: 10; min-height: 58px; padding: 9px max(16px, env(safe-area-inset-left)) 9px max(16px, env(safe-area-inset-right)); display: grid; grid-template-columns: minmax(170px, 1fr) auto minmax(170px, 1fr); align-items: center; gap: 12px; background: color-mix(in srgb, var(--surface) 94%, transparent); border-bottom: 1px solid var(--line); backdrop-filter: blur(12px); }
.viewer-toolbar button, .viewer-toolbar a { min-height: 38px; padding: 7px 11px; border: 1px solid var(--line); border-radius: 7px; color: var(--ink); background: var(--surface); text-decoration: none; }
.home-button { justify-self: start; }
.page-controls, .zoom-controls { display: flex; align-items: center; gap: 7px; }
.page-controls { justify-self: center; }
.page-controls label { display: flex; align-items: center; gap: 6px; white-space: nowrap; }
.page-controls input { width: 66px; min-height: 38px; padding: 6px 8px; border: 1px solid var(--line); border-radius: 7px; color: var(--ink); background: var(--surface); text-align: center; }
.zoom-controls { justify-self: end; }
.zoom-controls button { min-width: 38px; font-weight: 800; }
.zoom-controls .fit-preset-button { min-width: 96px; }
.zoom-controls .fit-preset-button[aria-pressed="true"] { color: #fff; border-color: #0d657d; background: #0d657d; }
#downloadIssue { color: #fff; border-color: #0d657d; background: #0d657d; }
.viewer-toolbar button:disabled { opacity: .42; }

main { min-height: calc(100vh - 130px); padding: 18px max(10px, env(safe-area-inset-left)) calc(30px + env(safe-area-inset-bottom)) max(10px, env(safe-area-inset-right)); }
.viewer-status { min-height: 22px; margin: 0 auto 10px; color: var(--muted); text-align: center; }
.viewer-status.error { color: #bd2638; font-weight: 700; }
.canvas-shell { position: relative; width: 100%; }
.canvas-stage { width: 100%; min-height: 65vh; margin: auto; padding: 12px; display: flex; align-items: flex-start; justify-content: flex-start; overflow: auto; overscroll-behavior-inline: contain; touch-action: pan-x pan-y pinch-zoom; transition: box-shadow 120ms ease; }
.canvas-stage::before,
.canvas-stage::after { content: ""; flex: 1 0 0; }
#pdfCanvas { flex: 0 0 auto; max-width: none; margin-inline: 0; background: #fff; box-shadow: var(--shadow); transform-origin: center center; }
.canvas-stage[data-swipe-edge="left"] { box-shadow: inset 24px 0 22px -22px var(--swipe-edge-glow); }
.canvas-stage[data-swipe-edge="right"] { box-shadow: inset -24px 0 22px -22px var(--swipe-edge-glow); }
.canvas-stage[data-page-turn="next-out"] #pdfCanvas { animation: page-turn-next-out 120ms ease-in both; }
.canvas-stage[data-page-turn="next-loading"] #pdfCanvas,
.canvas-stage[data-page-turn="previous-loading"] #pdfCanvas { opacity: 0; }
.canvas-stage[data-page-turn="next-in"] #pdfCanvas { animation: page-turn-next-in 180ms ease-out both; }
.canvas-stage[data-page-turn="previous-out"] #pdfCanvas { animation: page-turn-previous-out 120ms ease-in both; }
.canvas-stage[data-page-turn="previous-in"] #pdfCanvas { animation: page-turn-previous-in 180ms ease-out both; }
.page-turn-zone { display: none; position: fixed; z-index: 9; top: 130px; bottom: 0; width: clamp(48px, 6vw, 82px); padding: 0; border: 0; color: var(--brand-dark); background: transparent; cursor: pointer; opacity: .24; transition: opacity 140ms ease, background 140ms ease; touch-action: none; }
.page-turn-zone.previous { left: 0; }
.page-turn-zone.next { right: 0; }
.page-turn-zone span { display: grid; width: 36px; height: 58px; margin: auto; place-items: center; border: 1px solid color-mix(in srgb, var(--brand) 34%, transparent); border-radius: 999px; background: color-mix(in srgb, var(--surface) 88%, transparent); box-shadow: 0 5px 18px rgba(9, 41, 53, .16); font-size: 38px; line-height: 1; }
.page-turn-zone:hover,
.page-turn-zone:focus-visible { opacity: 1; background: linear-gradient(to right, color-mix(in srgb, var(--swipe-edge-glow) 60%, transparent), transparent); }
.page-turn-zone.next:hover,
.page-turn-zone.next:focus-visible { background: linear-gradient(to left, color-mix(in srgb, var(--swipe-edge-glow) 60%, transparent), transparent); }
.page-turn-zone:disabled { pointer-events: none; opacity: 0; }

@media (hover: hover) and (pointer: fine) {
  .page-turn-zone { display: flex; }
}

@keyframes page-turn-next-out {
  to { opacity: 0; transform: translateX(-34px) scale(.992); }
}
@keyframes page-turn-next-in {
  from { opacity: 0; transform: translateX(34px) scale(.992); }
  to { opacity: 1; transform: translateX(0) scale(1); }
}
@keyframes page-turn-previous-out {
  to { opacity: 0; transform: translateX(34px) scale(.992); }
}
@keyframes page-turn-previous-in {
  from { opacity: 0; transform: translateX(-34px) scale(.992); }
  to { opacity: 1; transform: translateX(0) scale(1); }
}

@media (prefers-reduced-motion: reduce) {
  .canvas-stage { transition: none; }
  .canvas-stage[data-page-turn] #pdfCanvas { animation: none; }
}

@media (max-width: 760px) {
  .viewer-header { grid-template-columns: 42px minmax(0, 1fr) auto; }
  .publisher-logo img { width: 38px; height: auto; }
  .viewer-brand a { font-size: 16px; }
  .viewer-brand span { font-size: 9px; }
  .viewer-preferences { align-items: flex-end; flex-direction: column; gap: 4px; }
  .icon-button { display: none; }
  .language-switch button { min-width: 34px; min-height: 31px; padding: 3px 6px; font-size: 12px; }
  .viewer-toolbar { grid-template-columns: 1fr; }
  .home-button { display: none; }
  .page-controls, .zoom-controls { justify-self: center; }
  .zoom-controls { flex-wrap: wrap; justify-content: center; }
  .zoom-controls .fit-preset-button { min-width: 84px; padding-left: 7px; padding-right: 7px; font-size: 12px; }
  .page-controls label span { position: absolute; width: 1px; height: 1px; overflow: hidden; clip-path: inset(50%); }
  #downloadIssue { width: 40px; overflow: hidden; white-space: nowrap; text-align: center; }
  #downloadIssue .download-label { position: absolute; width: 1px; height: 1px; overflow: hidden; clip-path: inset(50%); }
  .canvas-stage { padding: 2px; }
}

@media (max-width: 420px) {
  .viewer-toolbar { gap: 6px; padding-left: 8px; padding-right: 8px; }
  .page-controls, .zoom-controls { gap: 4px; }
  .viewer-toolbar button, .viewer-toolbar a { padding-left: 9px; padding-right: 9px; }
  .page-controls input { width: 54px; }
}