/**
 * Desirable Properties book site — layout primitives (header, container, spinner).
 * Brand: gold (#d4af37) on deep navy/charcoal (#0d1117).
 */
:root {
  --dp-content-max: 960px;
  --dp-content-max-wide: 1080px;
  --dp-gutter-x: 1.25rem;
  --dp-gutter-x-sm: 0.75rem;
  --dp-radius: 8px;
}

.dp-container,
.dp-site-inset {
  box-sizing: border-box;
  width: 100%;
  max-width: var(--dp-content-max);
  margin-left: auto;
  margin-right: auto;
  padding-left: max(var(--dp-gutter-x-sm), env(safe-area-inset-left, 0px));
  padding-right: max(var(--dp-gutter-x-sm), env(safe-area-inset-right, 0px));
}

@media (min-width: 768px) {
  .dp-container,
  .dp-site-inset {
    padding-left: max(var(--dp-gutter-x), env(safe-area-inset-left, 0px));
    padding-right: max(var(--dp-gutter-x), env(safe-area-inset-right, 0px));
  }
}

.dp-container-wide,
.dp-site-inset-wide {
  max-width: var(--dp-content-max-wide);
}

.dp-container-narrow {
  max-width: 640px;
}

.dp-container-medium {
  max-width: 720px;
}

/* Loading spinner — shared across the reader + cover */
.dp-loading {
  display: flex;
  align-items: center;
  justify-content: center;
  padding: 48px 24px;
}

.dp-loading .loading-spinner {
  width: 40px;
  height: 40px;
  border: 4px solid rgba(255, 255, 255, 0.12);
  border-top-color: var(--accent, #d4af37);
  border-radius: 50%;
  animation: dp-loading-spin 1s linear infinite;
  flex-shrink: 0;
}

@keyframes dp-loading-spin {
  from { transform: rotate(0deg); }
  to   { transform: rotate(360deg); }
}

/* Reader progress bar at top of header */
.dp-progress {
  position: relative;
  height: 3px;
  background: rgba(212, 175, 55, 0.12);
  flex-shrink: 0;
}

.dp-progress .dp-progress-bar {
  position: absolute;
  inset: 0 auto 0 0;
  width: 0%;
  background: var(--accent, #d4af37);
  transition: width 0.18s ease-out;
  box-shadow: 0 0 8px rgba(212, 175, 55, 0.45);
}

/* Part dividers in TOC */
.dp-part-head {
  margin: 14px 18px 4px;
  padding-top: 10px;
  border-top: 1px solid var(--nav-border, rgba(255, 255, 255, 0.08));
  font-size: 11px;
  font-weight: 700;
  letter-spacing: 0.12em;
  text-transform: uppercase;
  color: var(--muted, #8b949e);
}

.dp-part-head:first-child {
  border-top: none;
  margin-top: 6px;
  padding-top: 0;
}

.dp-part-head .dp-part-num {
  color: var(--accent, #d4af37);
  margin-right: 8px;
}

.dp-toc-part-title {
  display: block;
  font-size: 10px;
  color: var(--muted, #8b949e);
  text-transform: none;
  letter-spacing: 0.02em;
  margin-top: 2px;
  font-weight: 500;
}

/* Subtle scrollbar in reader */
.dp-reader-scroll::-webkit-scrollbar {
  width: 10px;
}

.dp-reader-scroll::-webkit-scrollbar-track {
  background: transparent;
}

.dp-reader-scroll::-webkit-scrollbar-thumb {
  background: rgba(212, 175, 55, 0.25);
  border-radius: 999px;
}

.dp-reader-scroll::-webkit-scrollbar-thumb:hover {
  background: rgba(212, 175, 55, 0.45);
}

/* Visually hidden but accessible */
.sr-only {
  position: absolute;
  width: 1px;
  height: 1px;
  padding: 0;
  margin: -1px;
  overflow: hidden;
  clip: rect(0, 0, 0, 0);
  white-space: nowrap;
  border: 0;
}

/* DP smart tag — clickable inline reference */
.dp-tag {
  display: inline-block;
  padding: 1px 6px;
  margin: 0 2px;
  font-size: 0.86em;
  font-weight: 600;
  font-family: ui-monospace, "SF Mono", Menlo, monospace;
  color: var(--accent, #d4af37);
  background: rgba(212, 175, 55, 0.10);
  border: 1px solid rgba(212, 175, 55, 0.32);
  border-radius: 4px;
  text-decoration: none;
  transition: background 0.18s, color 0.18s, border-color 0.18s;
  cursor: pointer;
  line-height: 1.4;
}

.dp-tag:hover,
.dp-tag:focus-visible {
  background: rgba(212, 175, 55, 0.22);
  color: var(--accent-hover, #e8c468);
  border-color: var(--accent, #d4af37);
  outline: none;
}

/* Inscription rail at end of each chapter */
.dp-rail {
  margin: 32px 0 8px;
  padding: 16px;
  border: 1px solid rgba(212, 175, 55, 0.28);
  border-radius: var(--dp-radius);
  background: rgba(212, 175, 55, 0.04);
}

.dp-rail .dp-rail-label {
  font-size: 11px;
  font-weight: 700;
  letter-spacing: 0.12em;
  text-transform: uppercase;
  color: var(--muted, #8b949e);
  margin: 0 0 6px;
}

.dp-rail .dp-rail-id {
  font-family: ui-monospace, "SF Mono", Menlo, monospace;
  font-size: 13px;
  word-break: break-all;
  color: var(--accent, #d4af37);
}

.dp-rail .dp-rail-id a {
  color: inherit;
  text-decoration: none;
}

.dp-rail .dp-rail-id a:hover {
  text-decoration: underline;
}

/* Part banner shown when reading the first DP of a new part */
.dp-part-banner {
  display: flex;
  align-items: center;
  gap: 14px;
  margin: 0 0 24px;
  padding: 14px 16px;
  border-left: 3px solid var(--accent, #d4af37);
  background: rgba(212, 175, 55, 0.06);
  border-radius: 4px;
}

.dp-part-banner .dp-part-banner-num {
  font-family: ui-monospace, "SF Mono", Menlo, monospace;
  font-size: 0.95rem;
  font-weight: 700;
  color: var(--accent, #d4af37);
  letter-spacing: 0.1em;
  flex-shrink: 0;
}

.dp-part-banner .dp-part-banner-text {
  font-size: 13px;
  color: var(--text, #e6edf3);
  line-height: 1.45;
}

.dp-part-banner .dp-part-banner-text strong {
  display: block;
  color: var(--accent, #d4af37);
  font-size: 14px;
  letter-spacing: 0.04em;
  margin-bottom: 2px;
}