/* Shared book reader (/b/<public_id>) */
:root {
  --rd-ink: #1a1f24;
  --rd-soft: #5a6570;
  --rd-line: #d8dde3;
  --rd-bg: #f7f4ef;
  --rd-paper: #fffcf7;
  --rd-sea: #1f4f5b;
  --rd-sea-deep: #163a44;
  --rd-on: #f4f7f8;
  --rd-serif: "Source Serif 4", Georgia, serif;
  --rd-display: Fraunces, Georgia, serif;
  --rd-sans: "IBM Plex Sans", system-ui, sans-serif;
}
* { box-sizing: border-box; }
body {
  margin: 0;
  min-height: 100vh;
  background:
    radial-gradient(1200px 600px at 10% -10%, #e8efe8 0%, transparent 55%),
    radial-gradient(900px 500px at 100% 0%, #efe6da 0%, transparent 50%),
    var(--rd-bg);
  color: var(--rd-ink);
  font-family: var(--rd-sans);
}
.rd-top {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 1rem 1.25rem;
  border-bottom: 1px solid var(--rd-line);
  background: rgba(255, 252, 247, 0.85);
  backdrop-filter: blur(8px);
  position: sticky;
  top: 0;
  z-index: 5;
}
.rd-brand {
  font-family: var(--rd-display);
  font-weight: 700;
  font-size: 1.15rem;
  color: var(--rd-sea-deep);
  text-decoration: none;
}
.rd-signin {
  color: var(--rd-sea);
  text-decoration: none;
  font-size: 0.9rem;
  font-weight: 500;
}
.rd-top-links {
  display: flex;
  gap: 1rem;
  align-items: center;
}
.rd-main {
  max-width: min(78rem, 100%);
  margin: 0 auto;
  padding: 1.5rem 1.5rem 3rem;
}
.rd-loading, .rd-hint, .rd-meta, .rd-essence {
  color: var(--rd-soft);
  line-height: 1.5;
}
.rd-title {
  font-family: var(--rd-display);
  font-weight: 700;
  font-size: clamp(1.6rem, 4vw, 2.2rem);
  margin: 0 0 0.5rem;
  line-height: 1.2;
}
.rd-gate, .rd-book {
  background: var(--rd-paper);
  border: 1px solid var(--rd-line);
  border-radius: 12px;
  padding: 1.5rem 1.75rem;
}
.rd-exports {
  display: flex;
  flex-wrap: wrap;
  gap: 0.5rem;
  margin-top: 0.85rem;
}
.rd-exports[hidden] {
  display: none !important;
}
.rd-field {
  display: flex;
  flex-direction: column;
  gap: 0.35rem;
  margin: 1rem 0;
  font-size: 0.85rem;
  font-weight: 500;
}
.rd-field input {
  font: inherit;
  padding: 0.65rem 0.75rem;
  border: 1px solid var(--rd-line);
  border-radius: 8px;
  background: #fff;
}
.rd-actions {
  display: flex;
  flex-wrap: wrap;
  gap: 0.6rem;
  margin-top: 1rem;
}
.rd-btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  min-height: 2.4rem;
  padding: 0 0.95rem;
  border-radius: 999px;
  border: 1px solid transparent;
  font: inherit;
  font-weight: 500;
  cursor: pointer;
  text-decoration: none;
}
.rd-btn.primary {
  background: var(--rd-sea-deep);
  color: var(--rd-on);
}
.rd-btn.ghost {
  background: transparent;
  border-color: var(--rd-line);
  color: var(--rd-ink);
}
.rd-error {
  color: #8b2e2e;
  font-size: 0.9rem;
}
.rd-hero {
  display: grid;
  gap: 1rem;
  margin-bottom: 1.5rem;
}
@media (min-width: 640px) {
  .rd-hero {
    grid-template-columns: 7.5rem 1fr;
    align-items: start;
  }
}
.rd-cover {
  width: 7.5rem;
  height: auto;
  border-radius: 6px;
  box-shadow: 0 8px 24px rgba(22, 58, 68, 0.18);
  background: #ddd;
}
.rd-toc-title {
  font-size: 0.8rem;
  text-transform: uppercase;
  letter-spacing: 0.04em;
  color: var(--rd-soft);
  margin: 0 0 0.5rem;
}
.rd-toc ol {
  margin: 0;
  padding: 0;
  list-style: none;
  display: grid;
  gap: 0.35rem;
}
.rd-toc button {
  width: 100%;
  text-align: left;
  border: 1px solid var(--rd-line);
  background: #fff;
  border-radius: 8px;
  padding: 0.65rem 0.8rem;
  font: inherit;
  cursor: pointer;
}
.rd-toc button:hover,
.rd-toc button:focus-visible {
  border-color: var(--rd-sea);
}
.rd-prose {
  font-family: var(--rd-serif);
  font-size: clamp(1.12rem, 0.4vw + 1.05rem, 1.22rem);
  line-height: 1.75;
  white-space: pre-wrap;
  max-width: 52rem;
  margin-left: auto;
  margin-right: auto;
}
.rd-nav {
  display: flex;
  flex-wrap: wrap;
  gap: 0.5rem;
  justify-content: space-between;
  margin-top: 1.75rem;
  margin-left: auto;
  margin-right: auto;
  padding-top: 1rem;
  border-top: 1px solid var(--rd-line);
  max-width: 52rem;
}
.rd-chapter-title {
  font-family: var(--rd-display);
  font-size: 1.45rem;
  margin: 0 auto 1rem;
  max-width: 52rem;
}
@media (min-width: 900px) {
  /* TOC | chapter | matching gutter → reading column stays centred */
  .rd-book {
    display: grid;
    grid-template-columns: minmax(11rem, 13rem) minmax(0, 54rem) minmax(11rem, 13rem);
    justify-content: center;
    column-gap: 1.75rem;
    row-gap: 1.25rem;
    align-items: start;
  }
  .rd-hero,
  .rd-social {
    grid-column: 1 / -1;
  }
  .rd-toc {
    grid-column: 1;
    grid-row: 2;
    position: sticky;
    top: 4.75rem;
    align-self: start;
    max-height: calc(100vh - 6rem);
    overflow: auto;
  }
  .rd-chapter {
    grid-column: 2;
    min-width: 0;
  }
  .rd-prose,
  .rd-nav,
  .rd-chapter-title {
    max-width: none;
    margin-left: 0;
    margin-right: 0;
  }
}
.rd-foot {
  text-align: center;
  padding: 1.5rem;
  color: var(--rd-soft);
  font-size: 0.85rem;
}
.rd-foot a { color: var(--rd-sea); }
.rd-buy {
  margin-top: 1rem;
  padding: 0.85rem 1rem;
  border: 1px solid var(--rd-line);
  border-radius: 8px;
  background: rgba(31, 79, 91, 0.06);
}
.rd-buy-copy {
  margin: 0 0 0.65rem;
  color: var(--rd-soft);
  font-size: 0.92rem;
  line-height: 1.4;
}
.rd-stars {
  display: flex;
  gap: 0.35rem;
  margin: 0.5rem 0 0.75rem;
}
.rd-star {
  font: inherit;
  font-size: 1.35rem;
  line-height: 1;
  border: none;
  background: transparent;
  color: #c5b8a4;
  cursor: pointer;
  padding: 0.1rem 0.15rem;
}
.rd-star.on { color: var(--rd-sea); }
.rd-star:disabled {
  cursor: default;
  opacity: 0.85;
}
.rd-comment-form {
  display: grid;
  gap: 0.5rem;
  margin: 0.75rem 0 1rem;
}
.rd-comment-form textarea {
  font: inherit;
  font-family: var(--rd-serif);
  padding: 0.55rem 0.65rem;
  border: 1px solid var(--rd-line);
  border-radius: 6px;
  background: var(--rd-paper);
  resize: vertical;
}
.rd-comments {
  list-style: none;
  margin: 0;
  padding: 0;
}
.rd-comments li {
  padding: 0.65rem 0;
  border-top: 1px solid var(--rd-line);
}
.rd-comments .who {
  font-size: 0.78rem;
  color: var(--rd-soft);
  margin: 0 0 0.2rem;
}
.rd-comments .body {
  margin: 0;
  font-family: var(--rd-serif);
  line-height: 1.45;
}

/* Hybrid SSR fallback (hidden once JS hydrates) */
.rd-ssr {
  max-width: 42rem;
  margin: 0 auto;
  padding: 0.5rem 0 2rem;
}
.rd-ssr-head {
  margin-bottom: 1.25rem;
}
.rd-ssr-title {
  font-family: var(--rd-display);
  font-size: clamp(1.6rem, 4vw, 2.2rem);
  margin: 0 0 0.35rem;
  line-height: 1.15;
}
.rd-ssr-meta {
  margin: 0;
  color: var(--rd-soft);
  font-size: 0.92rem;
}
.rd-ssr-cover img {
  display: block;
  max-width: min(14rem, 45vw);
  height: auto;
  border-radius: 6px;
  margin: 0 0 1.25rem;
  box-shadow: 0 8px 24px rgba(26, 31, 36, 0.12);
}
.rd-ssr-essence p,
.rd-ssr-prose p {
  font-family: var(--rd-serif);
  font-size: 1.05rem;
  line-height: 1.65;
  margin: 0 0 1rem;
}
.rd-ssr-chapter-title {
  font-family: var(--rd-display);
  font-size: 1.35rem;
  margin: 1.5rem 0 0.75rem;
}
.rd-ssr-cta {
  margin: 1.25rem 0 0;
}
.rd-ssr-foot {
  margin-top: 2rem;
  padding-top: 1rem;
  border-top: 1px solid var(--rd-line);
  font-size: 0.9rem;
  color: var(--rd-soft);
}
.rd-ssr-toc ol {
  margin: 0.5rem 0 0;
  padding-left: 1.25rem;
  font-family: var(--rd-serif);
}
.rd-ssr-toc-title {
  font-family: var(--rd-display);
  font-size: 1.15rem;
  margin: 1rem 0 0;
}
body.rd-hydrated .rd-ssr {
  display: none;
}

/* DecentMinds credit */
.rd-credit { margin-left: 0.6rem; opacity: 0.7; }