/* ══ BOOK READER ══ */
#book-screen { position: fixed; inset: 0; z-index: 300; background: #fff; }
.book-nav {
  width: 260px; flex-shrink: 0; background: var(--bg2);
  border-right: 1px solid rgba(26,86,232,0.1);
  display: flex; flex-direction: column;
  height: 100vh; overflow-y: auto;
}
.book-nav-header { padding: 24px 20px 16px; border-bottom: 1px solid rgba(26,86,232,0.1); }
.book-back-btn {
  display: flex; align-items: center; gap: 6px;
  background: none; border: none; cursor: pointer;
  font-family: var(--font); font-size: 13px; color: var(--text3);
  padding: 0; transition: color .2s;
}
.book-back-btn:hover { color: var(--accent); }
.book-toc { padding: 12px 0; }
.book-toc-item {
  padding: 9px 20px; font-size: 13px; color: var(--text2);
  cursor: pointer; transition: all .15s; border-left: 3px solid transparent;
}
.book-toc-item:hover { background: rgba(26,86,232,0.06); color: var(--ink); }
.book-toc-item.active { background: rgba(26,86,232,0.08); color: var(--accent); border-left-color: var(--accent); font-weight: 500; }
.book-main { flex: 1; display: flex; flex-direction: column; overflow: hidden; }
.book-topbar {
  padding: 12px 32px; border-bottom: 1px solid rgba(26,86,232,0.1);
  display: flex; align-items: center; gap: 14px;
  background: rgba(255,255,255,0.95); backdrop-filter: blur(10px);
  position: sticky; top: 0; z-index: 10;
}
.book-menu-btn { display: none; background: none; border: none; cursor: pointer; color: var(--text3); padding: 4px; }
.book-topbar-title { font-family: var(--font-mono); font-size: 12px; color: var(--text3); letter-spacing: .06em; }
.book-content { flex: 1; overflow-y: auto; }
.book-chapter { display: none; padding: 48px 64px 80px; max-width: 760px; }
.book-chapter.active { display: block; animation: fadeIn .3s ease; }
.book-ch-eyebrow { font-family: var(--font-mono); font-size: 10px; letter-spacing: .14em; color: var(--text3); text-transform: uppercase; margin-bottom: 8px; }
.book-ch-num { font-family: var(--font-mono); font-size: 11px; letter-spacing: .12em; color: var(--accent); text-transform: uppercase; margin-bottom: 6px; }
.book-ch-title { font-family: var(--font-display);font-weight:650; font-size: clamp(28px,4vw,44px); letter-spacing:-0.015em; color: var(--ink); margin: 0 0 24px; line-height: 1.1; }
.book-lead { font-size: 17px; color: var(--text2); line-height: 1.75; margin-bottom: 28px; font-weight: 400; }
.book-chapter h2 { font-family: var(--font-display);font-weight:650; font-size: 22px; letter-spacing:-0.015em; color: var(--ink); margin: 36px 0 16px; }
.book-chapter p { font-size: 15px; color: var(--text2); line-height: 1.75; margin: 0 0 16px; }
.book-quote { border-left: 3px solid var(--accent); padding: 12px 20px; margin: 24px 0; background: rgba(26,86,232,0.04); border-radius: 0 8px 8px 0; font-style: italic; font-size: 16px; color: var(--ink); line-height: 1.65; }
.book-callout { display: flex; gap: 12px; padding: 16px 18px; border-radius: 10px; border: 1px solid; margin: 24px 0; }
.book-callout-icon { flex-shrink: 0; margin-top: 1px; }
.book-callout-blue { background: rgba(26,86,232,0.06); border-color: rgba(26,86,232,0.2); color: #1e3a8a; }
.book-callout-blue strong { color: var(--accent); display: block; margin-bottom: 4px; }
.book-callout-blue p { color: #1e3a8a; margin: 0; font-size: 14px; }
.book-callout-blue .book-callout-icon svg { stroke: var(--accent); }
.book-callout-orange { background: rgba(249,115,22,0.06); border-color: rgba(249,115,22,0.2); }
.book-callout-orange strong { color: #c2410c; display: block; margin-bottom: 4px; }
.book-callout-orange p { color: #7c2d12; margin: 0 0 8px; font-size: 14px; }
.book-callout-orange .book-callout-icon svg { stroke: #f97316; }
.book-callout-red { background: rgba(220,38,38,0.06); border-color: rgba(220,38,38,0.2); }
.book-callout-red strong { color: #dc2626; display: block; margin-bottom: 4px; }
.book-callout-red p { color: #7f1d1d; margin: 0; font-size: 14px; }
.book-callout-red .book-callout-icon svg { stroke: #dc2626; }
.book-stats-row { display: flex; gap: 12px; margin: 20px 0; flex-wrap: wrap; }
.book-stat-card { flex: 1; min-width: 100px; background: var(--bg2); border: 1px solid rgba(26,86,232,0.12); border-radius: 10px; padding: 16px; text-align: center; }
.book-stat-num { font-family: var(--font-display);font-weight:650; font-size: 28px; color: var(--accent); line-height: 1; }
.book-stat-lbl { font-family: var(--font-mono); font-size: 10px; color: var(--text3); text-transform: uppercase; letter-spacing: .06em; margin-top: 4px; }
.book-platform-grid { display: grid; grid-template-columns: repeat(auto-fill, minmax(180px, 1fr)); gap: 12px; margin: 16px 0 24px; }
.book-platform { background: var(--bg2); border: 1px solid rgba(26,86,232,0.1); border-radius: 10px; padding: 14px; }
.book-platform-name { font-family: var(--font-display);font-weight:650; font-size: 14px; letter-spacing:-0.015em; color: var(--ink); margin-bottom: 6px; }
.book-platform-desc { font-size: 12px; color: var(--text3); line-height: 1.5; }
.book-list-cards { display: flex; flex-direction: column; gap: 10px; margin: 16px 0 24px; }
.book-list-card { display: flex; gap: 14px; align-items: flex-start; background: var(--bg2); border: 1px solid rgba(26,86,232,0.1); border-radius: 10px; padding: 14px 16px; }
.book-list-num { width: 28px; height: 28px; border-radius: 50%; background: var(--ink); color: #fff; font-family: var(--font-display);font-weight:650; font-size: 13px; display: flex; align-items: center; justify-content: center; flex-shrink: 0; }
.book-list-card strong { font-size: 14px; color: var(--ink); display: block; margin-bottom: 3px; }
.book-list-card p { font-size: 13px; color: var(--text3); margin: 0; line-height: 1.55; }
.book-ch-nav { display: flex; justify-content: space-between; margin-top: 48px; padding-top: 24px; border-top: 1px solid rgba(26,86,232,0.1); }
@media (max-width: 768px) {
  .book-nav { position: fixed; top: 0; left: -260px; bottom: 0; z-index: 400; transition: left .3s ease; box-shadow: none; }
  .book-nav.open { left: 0; box-shadow: 4px 0 24px rgba(0,0,0,0.15); }
  .book-menu-btn { display: block; }
  .book-chapter { padding: 24px 14px 72px; }
  .book-topbar { padding: 10px 16px; }
  .book-platform-grid { grid-template-columns: 1fr; }
  .book-stats-row { flex-direction: column; }
  .book-ch-nav { margin-top: 36px; gap: 10px; }
  .book-ch-nav .btn { padding: 12px 18px; font-size: 14px; flex: 1; text-align: center; }
  .book-svg-wrap { overflow-x: auto; -webkit-overflow-scrolling: touch; }
  .book-list-card { padding: 12px 14px; }
}
@media (max-width: 480px) {
  .book-chapter { padding: 18px 12px 80px; }
  .book-topbar { padding: 8px 12px; gap: 8px; }
  .book-topbar-title { font-size: 11px; overflow: hidden; white-space: nowrap; text-overflow: ellipsis; max-width: calc(100vw - 80px); }
  .book-ch-num { font-size: 10px; }
  .book-ch-title { font-size: clamp(24px,7vw,34px); margin-bottom: 16px; }
  .book-lead { font-size: 15px; }
  .book-chapter h2 { font-size: 19px; margin: 28px 0 12px; }
  .book-chapter p { font-size: 14px; line-height: 1.7; }
  .book-quote { font-size: 14px; padding: 10px 14px; }
  .book-ch-nav { flex-direction: column; gap: 10px; margin-top: 32px; }
  .book-ch-nav .btn { width: 100%; padding: 14px 16px; font-size: 15px; justify-content: center; text-align: center; }
  .book-list-num { width: 26px; height: 26px; font-size: 11px; flex-shrink: 0; }
  .book-list-card strong { font-size: 13px; }
  .book-list-card p { font-size: 12px; }
  .book-callout { padding: 12px 14px; gap: 10px; }
  .book-callout p { font-size: 13px; }
  .book-platform-name { font-size: 13px; }
  .book-platform-desc { font-size: 11px; }
  .book-stat-num { font-size: 22px; }
  .book-cover-hero { padding: 36px 20px 32px; }
  .book-cover-logo { font-size: clamp(52px,14vw,80px); }
  .book-cover-sub { font-size: 14px; }
  .book-cover-tagline { font-size: 13px; }
  .book-author-note { padding: 20px 16px; }
  .book-formula { padding: 14px 16px; }
}


/* ── extra book styles ── */
.book-cover-hero { background: linear-gradient(150deg,var(--ink) 0%,#1a3a8f 50%,var(--accent) 100%); padding: 60px 48px 52px; text-align:center; border-radius: 0 0 32px 32px; margin-bottom: 40px; position: relative; overflow: hidden; }
.book-cover-hero::before { content:''; position:absolute; inset:0; background: radial-gradient(ellipse at 70% 30%, rgba(168,192,255,0.15) 0%, transparent 60%); pointer-events:none; }
.book-vol-badge { display:inline-block; font-family:var(--font-mono); font-size:10px; letter-spacing:.14em; text-transform:uppercase; background:rgba(255,255,255,0.12); border:1px solid rgba(255,255,255,0.2); color:rgba(255,255,255,0.7); border-radius:20px; padding:4px 14px; margin-bottom:20px; }
.book-cover-logo { font-family:var(--font-display);font-weight:650; font-size:clamp(64px,12vw,96px); letter-spacing:-0.015em; color:#fff; line-height:1; margin-bottom:8px; }
.book-cover-sub { font-family:var(--font-display);font-weight:650; font-size:clamp(13px,2.5vw,17px); letter-spacing:-0.015em; color:rgba(255,255,255,0.55); text-transform:uppercase; margin-bottom:18px; }
.book-cover-tagline { font-family:var(--font); font-size:clamp(14px,2vw,16px); color:rgba(255,255,255,0.75); max-width:500px; margin:0 auto 24px; line-height:1.6; }
.book-cover-quote { font-family:var(--font-mono); font-size:11px; letter-spacing:.1em; color:rgba(255,255,255,0.4); }
.book-svg-wrap { margin: 28px 0; overflow-x: auto; }
.book-svg-wrap svg { display:block; margin:0 auto; max-width:100%; height:auto; }
.book-section-divider { border:none; border-top:1px solid rgba(26,86,232,0.12); margin:32px 0; }
.book-highlight { background:rgba(26,86,232,0.06); border-left:3px solid var(--accent); border-radius:0 8px 8px 0; padding:16px 20px; margin:20px 0; }
.book-highlight p { margin:0; font-size:14px; color:#1e3a8a; line-height:1.65; }
.book-highlight strong { display:block; font-size:13px; color:var(--accent); margin-bottom:4px; font-family:var(--font-mono); letter-spacing:.06em; text-transform:uppercase; }
.book-tag-grid { display:flex; flex-wrap:wrap; gap:8px; margin:16px 0 24px; }
.book-tag-pill { font-family:var(--font-mono); font-size:11px; letter-spacing:.06em; background:rgba(26,86,232,0.07); border:1px solid rgba(26,86,232,0.18); color:var(--accent); border-radius:20px; padding:5px 14px; }
.book-two-col { display:grid; grid-template-columns:1fr 1fr; gap:16px; margin:20px 0; }
@media(max-width:600px){ .book-two-col { grid-template-columns:1fr; } }
.book-checklist { list-style:none; margin:16px 0 24px; padding:0; display:flex; flex-direction:column; gap:10px; }
.book-checklist li { display:flex; align-items:flex-start; gap:10px; font-size:14px; color:var(--text2); line-height:1.6; }
.book-checklist li::before { content:''; display:block; width:18px; height:18px; border-radius:50%; background:var(--accent); flex-shrink:0; margin-top:2px; background-image:url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' viewBox='0 0 24 24' fill='none' stroke='white' stroke-width='3' stroke-linecap='round' stroke-linejoin='round'%3E%3Cpolyline points='20 6 9 17 4 12'/%3E%3C/svg%3E"); background-size:11px; background-repeat:no-repeat; background-position:center; }
.book-formula { background:var(--bg2); border:1.5px dashed rgba(26,86,232,0.25); border-radius:12px; padding:20px 24px; margin:20px 0; text-align:center; }
.book-formula .formula-text, .book-formula-body { font-family:var(--font-mono); font-size:14px; color:var(--ink); line-height:1.8; }
.book-formula .formula-label { font-size:11px; color:var(--text3); margin-top:6px; }
.book-formula-title { font-size:11px; color:var(--text3); margin-bottom:6px; font-family:var(--font-mono); letter-spacing:.06em; text-transform:uppercase; }
.book-author-note { background:linear-gradient(135deg,var(--ink),var(--accent)); border-radius:16px; padding:28px 32px; margin-top:40px; text-align:center; }
.book-author-note p { color:rgba(255,255,255,0.75); font-size:14px; line-height:1.7; margin:0 0 12px; }
.book-author-note strong { color:#fff; }
.book-author-note .author-contact { font-family:var(--font-mono); font-size:10px; color:rgba(255,255,255,0.4); letter-spacing:.08em; margin-top:12px; }
/* ── TOC read state ── */
.book-toc-item.read { color:#16a34a; }
.book-toc-item.read::after { content:'✓'; margin-left:auto; font-size:11px; color:#16a34a; font-weight:700; }
.book-toc-item { display:flex; align-items:center; }
/* ── Quiz styles ── */
.quiz-q { background:#f8fafc; border:1px solid rgba(26,86,232,0.1); border-radius:12px; padding:18px 20px; margin-bottom:16px; }
.quiz-q-text { font-size:15px; color:var(--ink); font-weight:600; margin-bottom:14px; line-height:1.5; }
.quiz-q-num { font-family:var(--font-mono); font-size:10px; color:var(--accent); letter-spacing:.1em; margin-bottom:6px; text-transform:uppercase; }
.quiz-options { display:flex; flex-direction:column; gap:8px; }
.quiz-opt { display:flex; align-items:center; gap:10px; padding:10px 14px; border-radius:8px; border:1.5px solid rgba(26,86,232,0.12); background:#fff; cursor:pointer; font-size:14px; color:var(--text2); transition:all .15s; text-align:left; }
.quiz-opt:hover { border-color:var(--accent); background:rgba(26,86,232,0.04); color:var(--ink); }
.quiz-opt.selected { border-color:var(--accent); background:rgba(26,86,232,0.07); color:var(--ink); font-weight:500; }
.quiz-opt.correct { border-color:#16a34a; background:rgba(22,163,74,0.08); color:#14532d; }
.quiz-opt.wrong { border-color:#dc2626; background:rgba(220,38,38,0.06); color:#7f1d1d; }
.quiz-opt.reveal-correct { border-color:#16a34a; background:rgba(22,163,74,0.08); color:#14532d; }
.quiz-opt-dot { width:16px; height:16px; border-radius:50%; border:2px solid currentColor; flex-shrink:0; display:flex; align-items:center; justify-content:center; font-size:9px; }
.quiz-result-banner { text-align:center; padding:32px 24px; border-radius:16px; margin:24px 0; }
.quiz-result-banner.pass { background:linear-gradient(135deg,var(--ink),var(--accent)); }
.quiz-result-banner.fail { background:linear-gradient(135deg,#1e293b,#475569); }
.quiz-score-big { font-family:var(--font-display);font-weight:650; font-size:72px; color:#fff; line-height:1; }
.quiz-score-lbl { font-family:var(--font-mono); font-size:10px; letter-spacing:.14em; color:rgba(255,255,255,0.55); text-transform:uppercase; margin-top:4px; }
.quiz-cert-badge { display:inline-flex; align-items:center; gap:10px; background:rgba(255,255,255,0.12); border:1px solid rgba(255,255,255,0.25); border-radius:30px; padding:10px 22px; margin:16px 0; color:#fff; font-size:14px; font-weight:600; }
/* ── Book progress bar in library card ── */
.book-read-progress { margin-top:10px; }
.book-read-bar-wrap { height:4px; background:rgba(26,86,232,0.1); border-radius:4px; overflow:hidden; margin-top:4px; }
.book-read-bar-fill { height:100%; background:var(--accent); border-radius:4px; transition:width .5s ease; }
.book-read-label { font-size:11px; color:var(--text3); font-family:var(--font-mono); }
/* ── Vol 2 locked card ── */
.book-card-locked-overlay { position:absolute; inset:0; background:rgba(13,27,62,0.5); display:flex; align-items:center; justify-content:center; border-radius:12px 12px 0 0; backdrop-filter:blur(2px); }
.book-card-coming { display:inline-flex; align-items:center; gap:6px; background:rgba(255,255,255,0.15); border:1px solid rgba(255,255,255,0.3); color:#fff; font-family:var(--font-mono); font-size:10px; letter-spacing:.1em; border-radius:20px; padding:5px 14px; }
.book-cover { position:relative; }

/* Vol. 2 green theme */
#book-screen-2 .book-ch-num { color: #059669; }
#book-screen-2 .book-toc-item.active { background: rgba(5,150,105,0.08); color: #059669; border-left-color: #059669; }
#book-screen-2 .book-toc-item.read::after { color: #059669; }
#book-screen-2 .book-toc-item.read { color: #059669; }
#book-screen-2 .book-quote { border-left-color: #059669; background: rgba(5,150,105,0.04); }
#book-screen-2 .book-callout-green { background: rgba(5,150,105,0.06); border-color: rgba(5,150,105,0.2); color: #064e3b; }
#book-screen-2 .book-callout-green strong { color: #059669; display: block; margin-bottom: 4px; }
#book-screen-2 .book-callout-green p { color: #065f46; margin: 0; font-size: 14px; }
#book-screen-2 .book-callout-green .book-callout-icon svg { stroke: #059669; }
.book-table-wrap { overflow-x: auto; -webkit-overflow-scrolling: touch; margin: 16px 0 24px; border-radius: 10px; border: 1px solid rgba(26,86,232,0.1); }
.book-table { width: 100%; border-collapse: collapse; font-size: 13px; min-width: 420px; }
.book-table th { background: var(--ink); color: #fff; padding: 10px 12px; text-align: left; font-weight: 600; font-family: var(--font-mono); font-size: 11px; letter-spacing: .06em; }
.book-table td { padding: 9px 12px; border-bottom: 1px solid rgba(26,86,232,0.08); color: var(--text2); vertical-align: top; line-height: 1.5; }
.book-table tr:nth-child(even) td { background: #f8fafc; }
.book-table tr.tbl-section td { background: #f0fdf4; color: #065f46; font-weight: 600; font-family: var(--font-mono); font-size: 11px; letter-spacing: .06em; text-transform: uppercase; }
.book-part-header { background: linear-gradient(135deg,#064e3b 0%,#059669 100%); border-radius: 16px; padding: 28px 24px; margin-bottom: 32px; }
.book-part-badge { font-family: var(--font-mono); font-size: 9px; letter-spacing: .18em; color: rgba(255,255,255,0.55); text-transform: uppercase; margin-bottom: 8px; }
.book-part-title { font-family: var(--font-display);font-weight:650; font-size: 28px; color: #fff; letter-spacing:-0.015em; line-height: 1.1; }
.book-part-sub { font-size: 13px; color: rgba(255,255,255,0.7); margin-top: 8px; }
.book-card-pair { display: grid; grid-template-columns: 1fr 1fr; gap: 12px; margin: 16px 0 20px; }
@media(max-width:600px) { .book-card-pair { grid-template-columns: 1fr; } }
.book-inner-card { background: var(--bg2); border: 1px solid rgba(26,86,232,0.1); border-radius: 10px; padding: 14px 16px; }
.book-inner-card h4 { font-family: var(--font-display);font-weight:650; font-size: 14px; letter-spacing:-0.015em; color: var(--ink); margin: 0 0 6px; }
.book-inner-card p { font-size: 12px; color: var(--text3); margin: 0; line-height: 1.55; }
.book-level-row { display: flex; align-items: center; gap: 12px; padding: 12px 16px; border-radius: 10px; margin-bottom: 8px; background: var(--bg2); border: 1px solid rgba(26,86,232,0.08); }
.book-level-num { width: 32px; height: 32px; border-radius: 50%; display: flex; align-items: center; justify-content: center; font-family: var(--font-display);font-weight:650; font-size: 16px; color: #fff; flex-shrink: 0; }
.book-level-body strong { font-size: 14px; color: var(--ink); display: block; margin-bottom: 2px; }
.book-level-body span { font-size: 12px; color: var(--text3); }

/* =========================================================
   Refinamiento editorial 2026 — lector de libros
   ========================================================= */
#book-screen, #book-screen-2 { position: fixed; inset: 0; z-index: 300; background: #fff; }
.book-nav { width: 280px; background: var(--paper); border-right: 1px solid var(--border); }
.book-nav-header { padding: 22px 22px 18px; border-bottom: 1px solid var(--border); }
.book-back-btn { font-family: var(--font); font-weight: 500; color: var(--text3); }
.book-back-btn:hover { color: var(--ink); }
.book-toc { padding: 10px 10px 24px; }
.book-toc-item { padding: 9px 12px; margin: 1px 0; border-radius: 10px; border-left: 0; font-size: 14px; line-height: 1.35; color: var(--text2); gap: 8px; }
.book-toc-item:hover { background: #fff; color: var(--ink); }
.book-toc-item.active { background: #fff; color: var(--accent); font-weight: 600; box-shadow: var(--shadow-sm); border: 1px solid var(--border); }
.book-toc-item.read { color: var(--text2); }
.book-toc-item.read::after { content: ""; width: 16px; height: 16px; flex-shrink: 0; border-radius: 50%; background: var(--green) url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' viewBox='0 0 24 24' fill='none' stroke='white' stroke-width='3.4' stroke-linecap='round' stroke-linejoin='round'%3E%3Cpolyline points='20 6 9 17 4 12'/%3E%3C/svg%3E") center/9px no-repeat; }
#book-screen-2 .book-toc-item.read { color: var(--text2); }
#book-screen-2 .book-toc-item.active { background: #fff; border-color: rgba(5,150,105,.25); }
.book-topbar { padding: 0 clamp(16px, 4vw, 40px); min-height: 60px; border-bottom: 1px solid var(--border); }
.book-topbar-title { font-family: var(--font); font-size: 14px; font-weight: 600; color: var(--ink); letter-spacing: -.01em; }
.book-chapter { padding: 56px clamp(18px, 6vw, 80px) 96px; max-width: 820px; margin: 0 auto; }
.book-ch-num, .book-ch-eyebrow { font-family: var(--font-mono); letter-spacing: .06em; }
.book-ch-title { font-size: clamp(32px, 4.6vw, 50px); line-height: 1.04; letter-spacing: -.035em; font-weight: 700; color: var(--ink); }
.book-chapter h2 { font-size: clamp(22px, 2.6vw, 27px); line-height: 1.2; letter-spacing: -.025em; font-weight: 700; margin: 48px 0 16px; }
.book-lead { font-family: var(--font); font-size: clamp(19px, 2vw, 22px); line-height: 1.55; color: var(--ink-2); letter-spacing: -.012em; }
.book-chapter p { font-size: 17px; line-height: 1.8; color: #2c3850; }
.book-quote { font-family: var(--font); font-weight: 500; font-size: 19px; line-height: 1.55; letter-spacing: -.012em; border-left-width: 2px; background: none; padding: 6px 0 6px 22px; border-radius: 0; color: var(--ink); }
.book-callout { border-radius: 14px; }
.book-cover-hero { border-radius: 24px; margin: 0 0 48px; padding: 72px 40px 64px; background: radial-gradient(120% 90% at 85% 0%, rgba(168,192,255,.28), transparent 55%), linear-gradient(160deg, #0a1430 0%, #13224a 55%, #1a56e8 140%); }
.book-cover-logo { font-weight: 800; letter-spacing: -.05em; }
.book-stat-card, .book-platform, .book-list-card, .book-inner-card, .book-level-row { background: #fff; border-color: var(--border); box-shadow: var(--shadow-sm); border-radius: 14px; }
.book-list-num { background: var(--ink); font-family: var(--font-mono); font-weight: 500; }
.book-ch-nav { gap: 12px; }
.quiz-q { background: #fff; border-color: var(--border); border-radius: 16px; padding: 22px; box-shadow: var(--shadow-sm); }
.quiz-q-text { font-size: 16px; }
.quiz-result-banner { border-radius: 22px; padding: 40px 28px; }
.quiz-result-banner.pass { background: radial-gradient(100% 80% at 50% 0%, rgba(184,145,58,.35), transparent 60%), linear-gradient(160deg, #0a1430, #13224a); }
.quiz-score-big { font-weight: 800; letter-spacing: -.04em; }
@media (max-width: 768px) {
  .book-nav { left: -290px; width: 280px; }
  .book-chapter { padding: 32px 18px 88px; }
  .book-chapter p { font-size: 16.5px; }
}