/* book-reader.css — EFA-style embedded book reader, shared across courses. */
.rd-wrap { display: grid; grid-template-columns: 300px 1fr; gap: 28px; max-width: 1400px; margin: 0 auto; padding: 0 20px 60px; }
@media (max-width: 980px) { .rd-wrap { grid-template-columns: 1fr; } .rd-toc { position: static !important; max-height: 320px !important; } }
/* A grid item's min-width defaults to auto, so the reading column could not
   shrink below its widest unbreakable content and pushed the page to a 443px
   scrollWidth on a 375px phone. Same floor as the flex case in style.css. */
.rd-wrap > * { min-width: 0; }
.rd-text pre, .rd-text table { max-width: 100%; overflow-x: auto; }

.rd-toc { position: sticky; top: 74px; align-self: start; background: var(--bg-2); border: 1px solid var(--rule);
  border-radius: 12px; padding: 14px; max-height: calc(100vh - 100px); overflow-y: auto; font-size: .86rem; }
.rd-toc h4 { margin: 0 0 10px; font-size: .64rem; text-transform: uppercase; letter-spacing: .15em; color: var(--ink-2); }
.rd-ch { margin-bottom: 4px; }
.rd-ch > summary { cursor: pointer; list-style: none; padding: 6px 8px; border-radius: 7px; color: var(--ink); font-weight: 600; font-size: .84rem; }
.rd-ch > summary::-webkit-details-marker { display: none; }
.rd-ch > summary:hover { background: var(--bg-3); }
.rd-ch > summary .n { font-family: 'JetBrains Mono', monospace; color: var(--accent, var(--green)); margin-right: 6px; font-size: .78rem; }
.rd-ch > summary .scope { display: inline-block; font-size: .6rem; letter-spacing: .06em; text-transform: uppercase; padding: 1px 5px; border-radius: 4px; margin-left: 5px; vertical-align: 1px; background: var(--bg-3); color: var(--ink-3); }
.rd-ch > summary .scope.core { background: rgba(126,231,163,.16); color: #7ee7a3; }
.rd-toc a { display: block; padding: 4px 8px 4px 22px; color: var(--ink-2); border: 0; border-radius: 6px; line-height: 1.35; }
.rd-toc a:hover { background: var(--bg-3); color: var(--accent, var(--green)); }
.rd-toc a.on { background: var(--accent-soft, rgba(122,178,122,.16)); color: var(--accent, var(--green)); }

.rd-bookswitch { display: flex; gap: 6px; margin-bottom: 12px; }
.rd-bookswitch button { flex: 1; background: var(--bg-3); border: 1px solid var(--rule); color: var(--ink-2); border-radius: 8px; padding: 7px 6px; cursor: pointer; font: inherit; font-size: .78rem; line-height: 1.25; }
.rd-bookswitch button.on { border-color: var(--accent, var(--green)); color: var(--accent, var(--green)); background: var(--accent-soft, rgba(122,178,122,.12)); }

.rd-bar { display: flex; gap: 10px; align-items: center; flex-wrap: wrap; margin-bottom: 16px;
  background: var(--bg-2); border: 1px solid var(--rule); border-radius: 12px; padding: 10px 14px; position: sticky; top: 66px; z-index: 5; }
.rd-bar input[type=search] { flex: 1; min-width: 180px; background: var(--bg-3); border: 1px solid var(--rule);
  border-radius: 8px; padding: 8px 12px; color: var(--ink); font: inherit; font-size: .9rem; }
.rd-bar input[type=search]:focus { outline: none; border-color: var(--accent, var(--green)); }
.rd-bar button { background: var(--bg-3); border: 1px solid var(--rule); color: var(--ink-2); border-radius: 8px;
  padding: 7px 12px; cursor: pointer; font: inherit; font-size: .85rem; }
.rd-bar button:hover { border-color: var(--accent, var(--green)); color: var(--accent, var(--green)); }
.rd-bar .pg { font-family: 'JetBrains Mono', monospace; font-size: .82rem; color: var(--ink-3); white-space: nowrap; }
.rd-seg { display: inline-flex; border: 1px solid var(--rule); border-radius: 8px; overflow: hidden; }
.rd-seg button { border: 0; border-radius: 0; }
.rd-seg button.on { background: var(--accent, var(--green)); color: #10131a; }

.rd-title { font-family: 'Fraunces', Georgia, serif; color: var(--accent, var(--green)); font-size: clamp(1.4rem,2.6vw,2rem); margin: 0 0 4px; }
.rd-sub { font-family: 'JetBrains Mono', monospace; font-size: .78rem; color: var(--ink-3); margin: 0 0 18px; }

.rd-text { background: var(--bg-2); border: 1px solid var(--rule); border-radius: 10px; padding: 20px 24px; line-height: 1.72; }
.rd-text p { margin: 0 0 14px; }
.rd-text p.sub { color: var(--accent, var(--green)); font-weight: 600; }
.rd-text mark { background: rgba(230,168,92,.34); color: var(--ink); border-radius: 3px; padding: 0 2px; }
.rd-anchor.flash { animation: rdflash 1.6s ease-out 1; border-radius: 6px; }
@keyframes rdflash { 0% { background: rgba(230,168,92,.28); } 100% { background: transparent; } }

.rd-pdf { width: 100%; height: calc(100vh - 180px); min-height: 480px; border: 1px solid var(--rule); border-radius: 10px; background: #fff; }

.rd-page { background: #fff; border: 1px solid var(--rule); border-radius: 10px; margin: 0 0 16px; overflow: hidden; }
.rd-page img { display: block; width: 100%; height: auto; }
.rd-page .lbl { font-family: 'JetBrains Mono', monospace; font-size: .72rem; color: #667; padding: 5px 10px; background: #f2f4f6; border-top: 1px solid #dde; }

.rd-hits { background: var(--bg-2); border: 1px solid var(--rule); border-radius: 12px; padding: 6px; margin-bottom: 16px; max-height: 60vh; overflow-y: auto; }
.rd-hit { display: block; padding: 10px 12px; border-radius: 8px; border: 0; color: var(--ink-2); border-bottom: 1px solid var(--rule); cursor: pointer; text-align: left; width: 100%; background: none; font: inherit; }
.rd-hit:last-child { border-bottom: 0; }
.rd-hit:hover { background: var(--bg-3); }
.rd-hit b { color: var(--accent, var(--green)); font-size: .8rem; font-family: 'JetBrains Mono', monospace; display: block; margin-bottom: 3px; }
.rd-hit span { font-size: .88rem; line-height: 1.5; }
.rd-note { color: var(--ink-3); font-size: .85rem; padding: 12px; }