/* =============================================================
   Multilevel Modeling for Psychology and the Social Sciences
   Web edition — book.css
   Three colour schemes (Harbor, Moss, Plum), each light and dark.
   Scheme: <html data-scheme="harbor|moss|plum">
   Mode:   <html data-mode="light|dark">
   ============================================================= */

/* ---------- scheme tokens ---------- */
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:root[data-scheme="plum"]{
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.ch-link:hover{color:var(--text);background:var(--bg-3)}
.ch-link.current{color:var(--accent-strong);border-left-color:var(--accent);background:var(--accent-wash);font-weight:600}
:root[data-mode="dark"] .ch-link.current{color:var(--accent)}
.ch-link.current .n{color:var(--accent)}
.sb-foot{padding:.8rem 1.3rem;border-top:1px solid var(--rule-soft);font-family:var(--sans);font-size:.74rem;color:var(--text-faint)}
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@media(min-width:1080px){.scrim{display:none}}

/* ---------- layout ---------- */
.shell{position:relative;z-index:1;padding-top:var(--tbh)}
@media(min-width:1080px){.shell{margin-left:var(--sbw)}}

/* =============================================================
   CHAPTER
   ============================================================= */
.chwrap{padding:0 1.25rem}
@media(min-width:700px){.chwrap{padding:0 2.5rem}}
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.chmain{min-width:0;max-width:var(--measure);margin:0 auto}
@media(min-width:1400px){.chmain{margin:0}}

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/* ---------- prose ---------- */
.prose > p, .prose li, .box-body p{hyphens:auto;-webkit-hyphens:auto}
.prose p{margin:0 0 1.15rem}
.prose h2{position:relative;margin:3.4rem 0 1.1rem;padding-top:1rem;border-top:1px solid var(--rule);
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.prose h2::before{content:"";position:absolute;top:-2px;left:0;width:3rem;height:3px;background:var(--accent);border-radius:2px}
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a.xref{text-decoration:none;color:var(--accent);border-bottom:1px solid transparent}
a.xref:hover{border-bottom-color:var(--accent)}
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/* ---------- equations ---------- */
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/* ---------- boxes ---------- */
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.box-taiwancase{--bx:var(--accent2)}
.box-labpointer{--bx:var(--accent2)}
.box-crosswalk{--bx:var(--text-faint)}
.box-chaptersummary{background:linear-gradient(0deg,var(--accent-wash),var(--accent-wash)),var(--surface)}
.box-objectives{background:linear-gradient(0deg,var(--accent-wash),var(--accent-wash)),var(--surface)}
.box-objectives ol li::marker{color:var(--accent);font-family:var(--sans);font-weight:700}

/* ---------- code ---------- */
.code{margin:1rem 0 1.3rem;border:1px solid var(--rule-soft);border-left:3px solid var(--accent-dim);border-radius:.45rem;background:var(--code-bg);overflow:hidden}
.box .code{margin:.6rem 0 .9rem}
.code-head{display:flex;justify-content:space-between;align-items:center;padding:.28rem .6rem .28rem .8rem;border-bottom:1px solid var(--rule-soft)}
.code-lang{font-family:var(--sans);font-size:.68rem;font-weight:700;letter-spacing:.14em;text-transform:uppercase;color:var(--text-faint)}
.copybtn{font-family:var(--sans);font-size:.72rem;padding:.08rem .5rem;border:1px solid var(--rule);border-radius:.3rem;background:transparent;color:var(--text-faint);cursor:pointer}
.copybtn:hover{color:var(--accent);border-color:var(--accent-dim)}
.code pre{font-variant-ligatures:none;margin:0;padding:.75rem .95rem;overflow-x:auto;font-family:var(--mono);font-size:.8rem;line-height:1.6;scrollbar-width:thin}
.code pre code{background:none;padding:0;font-size:inherit}
.code .k,.code .kd,.code .kn,.code .kr,.code .kc,.code .kt,.code .ow{color:var(--code-kw);font-weight:600}
.code .s,.code .s1,.code .s2,.code .sb,.code .sc,.code .sd,.code .se,.code .sh,.code .si,.code .sx,.code .sr{color:var(--code-str)}
.code .c,.code .c1,.code .cm,.code .cs,.code .ch,.code .cp{color:var(--code-com);font-style:italic}
.code .m,.code .mi,.code .mf,.code .mh,.code .mo,.code .il{color:var(--code-num)}
.code .nf,.code .nb,.code .bp,.code .fm{color:var(--code-fn)}
.code .o{color:var(--text-dim)}

/* ---------- figures ---------- */
.fig{margin:2.2rem 0;padding:0}
.cap{font-family:var(--sans);font-size:.9rem;line-height:1.45;margin:0 0 .7rem}
.capno{display:block;font-weight:700;color:var(--text);margin-bottom:.15rem}
.captitle{display:block;font-style:italic;color:var(--text)}
.fig-card{display:flex;flex-wrap:wrap;justify-content:center;gap:.5rem;padding:1rem;background:var(--fig-card);
  border:1px solid var(--rule-soft);border-radius:.55rem}
:root[data-mode="dark"] .fig-card{border-color:transparent}
.fig-img{display:block;width:var(--figw,100%);cursor:zoom-in}
.fig-img img{display:block;width:100%;height:auto}
.note{margin-top:.6rem;font-family:var(--sans);font-size:.84rem;line-height:1.55;color:var(--text-dim)}
.note p{margin:0 0 .4rem}
.fig:target .fig-card,.tbl:target{box-shadow:0 0 0 3px var(--accent-wash)}

/* ---------- tables (APA) ---------- */
.tbl{margin:2.2rem 0;border-radius:.4rem}
.tblwrap{overflow-x:auto;scrollbar-width:thin;margin:.2rem 0}
.tblwrap table{border-collapse:collapse;width:100%;font-family:var(--sans);font-size:.86rem;line-height:1.45;
  border-top:1.6px solid var(--text);border-bottom:1.6px solid var(--text)}
.tblwrap th,.tblwrap td{padding:.42rem .7rem;vertical-align:top}
.tblwrap thead th{font-weight:600;color:var(--text);vertical-align:bottom}
.tblwrap thead tr:last-child th{border-bottom:1px solid var(--text)}
.tblwrap tr.rule td,.tblwrap tr.rule th{border-bottom:1px solid var(--text-faint)}
.tblwrap tr.cmid th,.tblwrap tr.cmid td{border-bottom:1px solid var(--rule)}
.tblwrap tr.space-before td{padding-top:.9rem}
.tblwrap tbody tr:hover td{background:var(--accent-wash)}
.tblwrap .al{text-align:left}.tblwrap .ac{text-align:center}.tblwrap .ar{text-align:right;font-variant-numeric:tabular-nums}
.tblwrap .ind1{padding-left:1.7rem}.tblwrap .ind2{padding-left:2.7rem}.tblwrap .ind3{padding-left:3.7rem}
.tblwrap tr.grouprow td{font-style:italic;color:var(--text-dim);padding-top:.7rem}
.tblwrap td code{font-size:.8rem}
.prose > .tblwrap{margin:1.4rem 0}

/* ---------- key terms, exercises, solutions ---------- */
.keyterms{list-style:none;padding:0 !important;display:flex;flex-wrap:wrap;gap:.45rem;margin:0 0 1.4rem}
.keyterms li{margin:0;padding:.2rem .7rem;font-family:var(--sans);font-size:.86rem;background:var(--surface);
  border:1px solid var(--rule);border-radius:999px;color:var(--text-dim)}
ol.exlist{list-style:none;padding-left:0;counter-reset:none}
ol.exlist > li{position:relative;padding-left:2.9rem;margin-bottom:.8rem}
ol.exlist > li::before{content:attr(data-label);position:absolute;left:0;top:.08rem;min-width:2.3rem;text-align:center;
  font-family:var(--sans);font-size:.78rem;font-weight:700;color:var(--accent);background:var(--accent-wash);
  border-radius:.3rem;padding:.05rem .3rem}
ol.exlist > li:target{background:var(--accent-wash);border-radius:.35rem}
.sollink{font-family:var(--sans);font-size:.78rem;font-weight:600;text-decoration:none;white-space:nowrap;
  padding:.02rem .45rem;border:1px solid var(--accent-dim);border-radius:.3rem;margin-left:.2rem}
.sollink:hover{background:var(--accent-wash)}
.solhead{margin:2rem 0 .7rem;padding:.7rem .95rem;background:var(--surface);border:1px solid var(--rule-soft);
  border-left:4px solid var(--accent);border-radius:.45rem;line-height:1.55}
.solhead:target{box-shadow:0 0 0 3px var(--accent-wash)}
.solno{display:inline-block;font-family:var(--sans);font-weight:700;font-size:.9rem;margin-right:.5rem;text-decoration:none}
.soltask{font-style:italic;color:var(--text-dim)}

/* ---------- references ---------- */
.refs{margin-top:3rem}
.csl-bib-body{font-size:.9rem;line-height:1.6;color:var(--text-dim)}
.csl-entry{padding-left:2rem;text-indent:-2rem;margin-bottom:.6rem;overflow-wrap:anywhere}
.csl-entry:target{background:var(--accent-wash);border-radius:.25rem}
.csl-entry a{color:var(--accent)}

/* ---------- chapter end ---------- */
.chapcite{margin:3rem 0 0;padding:1rem 1.2rem;background:var(--surface);border:1px solid var(--rule-soft);border-radius:.5rem;
  font-family:var(--sans);font-size:.84rem;line-height:1.6;color:var(--text-dim)}
.chapcite b{display:block;font-size:.68rem;letter-spacing:.16em;text-transform:uppercase;color:var(--accent);margin-bottom:.3rem}
.chnav{display:grid;gap:1rem;margin:2.2rem 0 4rem}
@media(min-width:700px){.chnav{grid-template-columns:1fr 1fr}}
.chnav a{display:block;padding:1rem 1.2rem;border:1px solid var(--rule);border-radius:.55rem;text-decoration:none;background:var(--surface);
  transition:border-color .15s,transform .15s}
.chnav a:hover{border-color:var(--accent);transform:translateY(-1px)}
.chnav .dir{font-family:var(--sans);font-size:.7rem;letter-spacing:.16em;text-transform:uppercase;color:var(--accent)}
.chnav .t{font-family:var(--sans);font-weight:600;color:var(--text);line-height:1.35;margin-top:.2rem}
.chnav .next{text-align:right}
.chnav .empty{visibility:hidden}

/* ---------- right rail ---------- */
.rail{display:none}
@media(min-width:1400px){.rail{display:block;position:sticky;top:var(--tbh);align-self:start;max-height:calc(100vh - var(--tbh));
  overflow-y:auto;padding:3.6rem 0 3rem;scrollbar-width:none}}
.rail .rh{font-family:var(--sans);font-size:.68rem;font-weight:700;letter-spacing:.16em;text-transform:uppercase;color:var(--text-faint);
  margin-bottom:.7rem;padding-bottom:.5rem;border-bottom:1px solid var(--rule-soft)}
.rail a{display:flex;gap:.45rem;padding:.26rem 0 .26rem .75rem;font-family:var(--sans);font-size:.8rem;line-height:1.4;color:var(--text-faint);
  text-decoration:none;border-left:2px solid var(--rule-soft);transition:color .15s,border-color .15s}
.rail a .rn{flex:none;min-width:1.9rem;font-variant-numeric:tabular-nums}
.rail a:hover{color:var(--text)}
.rail a.active{color:var(--accent);border-left-color:var(--accent)}

/* ---------- footer ---------- */
.foot{position:relative;z-index:1;padding:2.2rem 1.5rem 3rem;border-top:1px solid var(--rule-soft);font-family:var(--sans);
  font-size:.8rem;line-height:1.8;color:var(--text-faint)}
@media(min-width:1080px){.foot{padding:2.2rem 3rem 3rem}}
.foot a{color:var(--text-dim)}
.foot .fl{display:flex;flex-wrap:wrap;gap:.3rem 1.4rem}

/* =============================================================
   HOME
   ============================================================= */
.hero{position:relative;overflow:hidden;padding:4.5rem 1.5rem 4rem;border-bottom:1px solid var(--rule-soft)}
@media(min-width:1080px){.hero{padding:5.5rem 3.5rem 4.5rem}}
.hero::before{content:"";position:absolute;inset:0;pointer-events:none;
  background:radial-gradient(60rem 30rem at 12% -10%,var(--accent-wash),transparent 65%),
             radial-gradient(50rem 28rem at 100% 10%,var(--accent2-wash),transparent 60%)}
.ghost{position:absolute;left:-1vw;bottom:-3.2vw;font-family:var(--serif);font-style:italic;font-weight:700;letter-spacing:-.04em;
  font-size:clamp(7rem,19vw,20rem);line-height:.8;color:var(--text);opacity:calc(var(--wm-op) * 1.25);pointer-events:none;user-select:none;white-space:nowrap}
.hero-grid{position:relative;display:grid;gap:2.5rem;align-items:center;max-width:78rem;margin:0 auto}
@media(min-width:1000px){.hero-grid{grid-template-columns:minmax(0,1.15fr) minmax(0,.85fr)}}
.eyebrow{font-family:var(--sans);font-size:.76rem;font-weight:600;letter-spacing:.22em;text-transform:uppercase;color:var(--accent);margin-bottom:1.3rem}
.h-title{margin:0;font-family:var(--sans);font-weight:800;font-size:clamp(2.7rem,7vw,5.2rem);line-height:1;letter-spacing:-.025em}
.h-sub{margin:.7rem 0 0;font-family:var(--serif);font-style:italic;font-weight:400;font-size:clamp(1.25rem,2.6vw,1.8rem);color:var(--text-dim);line-height:1.3}
.h-tag{margin:.9rem 0 0;font-family:var(--sans);font-weight:600;font-size:clamp(.95rem,1.6vw,1.12rem);letter-spacing:.14em;text-transform:uppercase;color:var(--accent2)}
.h-rule{width:4.5rem;height:3px;border-radius:2px;background:var(--accent);margin:1.9rem 0 1.4rem}
.h-author{font-family:var(--sans);font-size:1.18rem;font-weight:600}
.h-author .zh{margin-left:.5rem;font-weight:500;color:var(--text-dim)}
.h-aff{font-family:var(--sans);font-size:.88rem;color:var(--text-faint);margin-top:.25rem}
.cta{display:flex;flex-wrap:wrap;gap:.7rem;margin-top:2.1rem}
.btn{display:inline-flex;align-items:center;gap:.5rem;padding:.72rem 1.3rem;font-family:var(--sans);font-size:.92rem;font-weight:600;
  text-decoration:none;border-radius:.5rem;border:1px solid var(--accent);color:#fff;background:var(--accent);cursor:pointer;
  transition:background .15s,transform .15s,border-color .15s}
:root[data-mode="dark"] .btn:not(.ghost-btn){color:var(--bg)}
.btn:hover{transform:translateY(-1px);background:var(--accent-strong);border-color:var(--accent-strong)}
.btn.ghost-btn{background:transparent;color:var(--text);border-color:var(--rule)}
.btn.ghost-btn:hover{border-color:var(--accent);color:var(--accent);background:var(--accent-wash)}
.stats{display:flex;flex-wrap:wrap;gap:1.6rem;margin-top:2.3rem;font-family:var(--sans)}
.stat b{display:block;font-size:1.6rem;font-weight:700;color:var(--text);line-height:1.1}
.stat span{font-size:.76rem;letter-spacing:.1em;text-transform:uppercase;color:var(--text-faint)}
.hero-art{position:relative;margin:0 auto;width:100%;max-width:27rem}
.hero-art svg{width:100%;height:auto;display:block;filter:drop-shadow(0 18px 40px rgba(0,0,0,.08))}
.hero-art figcaption{font-family:var(--sans);font-size:.8rem;line-height:1.5;color:var(--text-faint);text-align:center;margin-top:.7rem}

.sec{position:relative;padding:4rem 1.5rem;border-bottom:1px solid var(--rule-soft)}
@media(min-width:1080px){.sec{padding:4.6rem 3.5rem}}
.sec-in{max-width:78rem;margin:0 auto}
.sec-h{display:flex;align-items:baseline;gap:1rem;margin-bottom:.6rem}
.sec-h .num{font-family:var(--sans);font-size:.78rem;font-weight:700;letter-spacing:.2em;color:var(--accent)}
.sec-h h2{margin:0;font-family:var(--sans);font-weight:700;font-size:clamp(1.5rem,3vw,2rem);line-height:1.2}
.sec-lead{max-width:48rem;margin:.4rem 0 2.2rem;color:var(--text-dim)}
.about{display:grid;gap:2rem}
@media(min-width:1000px){.about{grid-template-columns:1.2fr .8fr}}
.about p{margin:0 0 1.05rem}
.facts{display:grid;gap:.8rem;align-content:start}
.fact{padding:1rem 1.1rem;background:var(--surface);border:1px solid var(--rule-soft);border-radius:.55rem}
.fact b{display:block;font-family:var(--sans);font-size:.72rem;letter-spacing:.14em;text-transform:uppercase;color:var(--accent);margin-bottom:.2rem}
.fact span{display:block;font-size:.94rem;color:var(--text-dim);line-height:1.55}

.lexicon{display:grid;gap:1rem;grid-template-columns:repeat(auto-fill,minmax(13.5rem,1fr))}
.lex{display:flex;gap:.9rem;align-items:center;padding:.9rem 1rem;background:var(--surface);border:1px solid var(--rule-soft);border-radius:.55rem}
.lex svg{width:3.4rem;height:3.4rem;flex:none}
.lex b{display:block;font-family:var(--sans);font-size:.95rem}
.lex span{display:block;font-size:.86rem;color:var(--text-dim);line-height:1.45;margin-top:.15rem}
.gallery{display:grid;gap:1.1rem;margin-top:1.6rem}
@media(min-width:900px){.gallery{grid-template-columns:repeat(3,1fr)}}
.gallery a{display:block;text-decoration:none;color:var(--text-dim);font-family:var(--sans);font-size:.84rem;line-height:1.4}
.gallery .gimg{background:var(--fig-card);border:1px solid var(--rule-soft);border-radius:.55rem;padding:.8rem;aspect-ratio:16/11;display:flex;align-items:center;justify-content:center;transition:border-color .15s,transform .15s}
.gallery a:hover .gimg{border-color:var(--accent);transform:translateY(-2px)}
.gallery img{max-width:100%;max-height:100%;object-fit:contain}
.gallery .gcap{margin-top:.5rem}
.gallery .gcap b{color:var(--text)}

.paths{display:grid;gap:1.1rem}
@media(min-width:760px){.paths{grid-template-columns:repeat(2,1fr)}}
@media(min-width:1200px){.paths{grid-template-columns:repeat(4,1fr)}}
.path{padding:1.3rem 1.3rem 1.2rem;background:var(--surface);border:1px solid var(--rule-soft);border-top:3px solid var(--accent);border-radius:.55rem}
.path:nth-child(2){border-top-color:var(--accent2)}
.path:nth-child(3){border-top-color:var(--accent-dim)}
.path:nth-child(4){border-top-color:var(--text-faint)}
.path h3{margin:0 0 .35rem;font-family:var(--sans);font-size:1.05rem}
.path .route{font-family:var(--sans);font-size:.8rem;font-weight:600;color:var(--accent);margin-bottom:.6rem;line-height:1.45}
.path p{margin:0;font-size:.9rem;line-height:1.55;color:var(--text-dim)}

.parts{display:grid;gap:1rem}
@media(min-width:860px){.parts{grid-template-columns:repeat(2,1fr)}}
@media(min-width:1300px){.parts{grid-template-columns:repeat(3,1fr)}}
.part{padding:1.2rem 1.3rem 1rem;background:var(--surface);border:1px solid var(--rule-soft);border-radius:.55rem}
.part-top{display:flex;gap:.7rem;align-items:baseline;padding-bottom:.6rem;margin-bottom:.4rem;border-bottom:1px solid var(--rule-soft)}
.part-top .rn{font-family:var(--sans);font-weight:800;font-size:1.25rem;color:var(--accent)}
.part-top h3{margin:0;font-family:var(--sans);font-size:.98rem;line-height:1.35}
.part ol{list-style:none;margin:0;padding:0}
.part li a{display:flex;gap:.7rem;padding:.32rem .2rem;text-decoration:none;color:var(--text-dim);font-size:.93rem;line-height:1.45;border-radius:.3rem}
.part li a:hover{color:var(--accent);background:var(--accent-wash)}
.part li .n{flex:none;min-width:1.5rem;text-align:right;font-family:var(--sans);font-size:.8rem;font-weight:700;color:var(--text-faint);padding-top:.1rem}

.elements{display:grid;gap:.8rem;grid-template-columns:repeat(auto-fill,minmax(15rem,1fr))}
.el{display:flex;gap:.7rem;align-items:flex-start;padding:.85rem 1rem;background:var(--surface);border:1px solid var(--rule-soft);
  border-left:4px solid var(--bx,var(--accent));border-radius:.5rem}
.el .ico{width:1.3rem;height:1.3rem;flex:none;stroke:var(--bx,var(--accent));fill:none;stroke-width:1.7;stroke-linecap:round;stroke-linejoin:round;margin-top:.1rem}
.el b{display:block;font-family:var(--sans);font-size:.92rem}
.el span{display:block;font-size:.84rem;color:var(--text-dim);line-height:1.45;margin-top:.15rem}

/* =============================================================
   SEARCH, LIGHTBOX
   ============================================================= */
.ovl{position:fixed;inset:0;z-index:90;display:none;padding:4.5rem 1rem 1rem;background:rgba(10,14,20,.5);backdrop-filter:blur(4px)}
.ovl.on{display:block}
.spanel{max-width:44rem;margin:0 auto;background:var(--surface);border:1px solid var(--rule);border-radius:.7rem;box-shadow:var(--shadow);
  overflow:hidden;display:flex;flex-direction:column;max-height:min(36rem,82vh)}
.sfield{display:flex;align-items:center;gap:.7rem;padding:.9rem 1.1rem;border-bottom:1px solid var(--rule-soft)}
.sfield svg{width:1.1rem;height:1.1rem;stroke:var(--text-faint);fill:none;stroke-width:1.7;flex:none}
.sfield input{flex:1;background:transparent;border:0;outline:0;color:var(--text);font-family:var(--sans);font-size:1.05rem}
.sfield .esc{font-family:var(--sans);font-size:.7rem;padding:.08rem .36rem;border:1px solid var(--rule);border-radius:.25rem;color:var(--text-faint)}
.sres{overflow-y:auto;padding:.3rem 0}
.sres a{display:block;padding:.7rem 1.1rem;text-decoration:none;border-left:3px solid transparent;color:var(--text)}
.sres a:hover,.sres a.sel{background:var(--accent-wash);border-left-color:var(--accent)}
.sres .loc{font-family:var(--sans);font-size:.74rem;font-weight:600;color:var(--accent);margin-bottom:.15rem}
.sres .snip{font-size:.88rem;line-height:1.55;color:var(--text-dim)}
.sres mark{background:var(--accent2-wash);color:var(--text);padding:0 .1em;border-radius:.15em}
.sempty{padding:1.5rem 1.1rem;text-align:center;font-family:var(--sans);font-size:.88rem;color:var(--text-faint)}
.lightbox{position:fixed;inset:0;z-index:95;display:none;align-items:center;justify-content:center;padding:2rem;
  background:rgba(10,12,16,.82);cursor:zoom-out}
.lightbox.on{display:flex}
.lightbox img{max-width:96vw;max-height:92vh;background:#fff;padding:1rem;border-radius:.5rem;box-shadow:0 20px 60px rgba(0,0,0,.4)}

/* ---------- print ---------- */
@media print{
  .sidebar,.topbar,.rail,.chnav,.ovl,#progress,.scrim,.watermark,.lightbox,.copybtn,.hlink{display:none!important}
  .shell{margin:0;padding:0}body{background:#fff;color:#000;font-size:11pt}
  .box,.fig-card,.code{break-inside:avoid}
}

/* ---------- crosswalk tabs ---------- */
.xtabs{margin:.4rem 0 1rem}
.xtab-strip{display:flex;flex-wrap:wrap;gap:.3rem;margin-bottom:.1rem}
.xtab{font-family:var(--sans);font-size:.8rem;font-weight:600;padding:.28rem .8rem;border:1px solid var(--rule);border-radius:.4rem .4rem 0 0;
  background:transparent;color:var(--text-dim);cursor:pointer}
.xtab:hover{color:var(--accent)}
.xtab.on{background:var(--code-bg);color:var(--accent);border-color:var(--accent-dim);border-bottom-color:var(--code-bg)}
.xpanel .code{margin-top:0;border-top-left-radius:0}
.xnote{font-size:.88rem;color:var(--text-dim);margin:.4rem 0 .5rem}
.js .xpanel{display:none}
.js .xpanel.on{display:block}
.xpanel .code{position:relative}
.xpanel .code-head{position:absolute;top:0;right:0;border:0;padding:.35rem .45rem;background:var(--code-bg);border-bottom-left-radius:.4rem}
.xpanel .code-lang{display:none}

/* =============================================================
   V02: multilevel hero, password protection (Chapters 5–32, each with its own password, and Appendix G)
   ============================================================= */
/* ---------- hero visual: three stacked levels ---------- */
.hero-art{max-width:34rem}
@media(min-width:1000px){.page-home .hero-grid{grid-template-columns:minmax(0,1fr) minmax(0,1fr)}}
.hero-art svg.mlviz{filter:none}
.mlviz{--k1:var(--accent);--k2:#D08A2E;--k3:#2E8B7A;display:block;width:100%;height:auto;overflow:visible}
:root[data-mode="dark"] .mlviz{--k2:#E7AE62;--k3:#5CC2AE}
:root[data-scheme="moss"] .mlviz{--k2:#C46E4A;--k3:#4E6FA8}
:root[data-scheme="moss"][data-mode="dark"] .mlviz{--k2:#E59D7C;--k3:#8FAEE0}
:root[data-scheme="plum"] .mlviz{--k2:#B08A3E;--k3:#2E7F8A}
:root[data-scheme="plum"][data-mode="dark"] .mlviz{--k2:#DDBD6E;--k3:#6CC3CC}
.mlviz .pf{fill:url(#mlvG);stroke:var(--plate);stroke-width:1.3;stroke-linejoin:round}
.mlviz .pg{fill:none;stroke:var(--plate);stroke-width:.6;opacity:.22}
.mlviz .t1{--k:var(--k1);--dl:0s}.mlviz .t2{--k:var(--k2);--dl:1.8s}.mlviz .t3{--k:var(--k3);--dl:3.6s}
.mlviz .lk{fill:none;stroke:var(--k);stroke-width:1.1;opacity:.42}
.mlviz .l21{stroke-width:.8;opacity:.32}
.mlviz .ps{fill:none;stroke:var(--k);stroke-width:2.4;stroke-linecap:round;stroke-dasharray:12 300;stroke-dashoffset:12;opacity:0}
.mlviz .p32{animation:mlp32 5.4s linear infinite;animation-delay:var(--dl)}
.mlviz .p21{animation:mlp21 5.4s linear infinite;animation-delay:var(--dl)}
.mlviz .sc{fill:var(--k);stroke:var(--bg);stroke-width:2.5}
.mlviz .cl{fill:var(--bg);stroke:var(--k);stroke-width:2.6}
.mlviz .pu{fill:var(--k);opacity:.8;transform-box:fill-box;transform-origin:center;animation:mlpu 5.4s ease-out infinite;animation-delay:var(--dl)}
.mlviz text{font-family:var(--sans);fill:var(--text-dim)}
.mlviz .lv{font-size:12px;font-weight:700;letter-spacing:.2em;fill:var(--accent)}
.mlviz .lvn{font-size:16px;font-family:var(--serif)}
.mlviz .eqn{font-family:var(--serif);font-size:16.5px;fill:var(--text)}
.mlviz .sb,.mlviz .sp{font-size:11.5px}
.mlviz .tree{transition:opacity .25s}
.mlviz .trees:hover .tree:not(:hover){opacity:.2}
@keyframes mlp32{0%{opacity:0;stroke-dashoffset:12}2%{opacity:.95}16%{opacity:.95;stroke-dashoffset:-100}17%,100%{opacity:0;stroke-dashoffset:-100}}
@keyframes mlp21{0%,16%{opacity:0;stroke-dashoffset:12}18%{opacity:.95}31%{opacity:.95;stroke-dashoffset:-100}32%,100%{opacity:0;stroke-dashoffset:-100}}
@keyframes mlpu{0%,30%{transform:scale(1);opacity:.8}34%{transform:scale(1.55);opacity:1}46%,100%{transform:scale(1);opacity:.8}}
@media (prefers-reduced-motion:reduce){.mlviz .ps,.mlviz .pu{animation:none}}
.h-note{margin-top:2rem;max-width:34rem;font-family:var(--sans);font-size:.95rem;line-height:1.6;color:var(--text-dim)}

/* ---------- lock icons in the contents and sidebar ---------- */
.lk{display:inline-flex;align-items:center;margin-left:auto;padding-left:.4rem;color:var(--text-faint);flex:none}
.lk svg{width:.85rem;height:.85rem;fill:none;stroke:currentColor;stroke-width:2;stroke-linecap:round;stroke-linejoin:round}
.lk .open{display:none}
.lk.on .shut{display:none}
.lk.on .open{display:inline}
.lk.on{color:var(--accent-dim)}

/* ---------- lock card on a protected chapter ---------- */
.lockcard{margin:2.5rem 0 3rem;padding:1.8rem 1.6rem 1.6rem;background:var(--surface);border:1px solid var(--rule);
  border-top:4px solid var(--accent);border-radius:.6rem;box-shadow:var(--shadow);font-family:var(--sans)}
.lockcard .lkico{width:2.4rem;height:2.4rem;fill:none;stroke:var(--accent);stroke-width:1.7;stroke-linecap:round;stroke-linejoin:round}
.lockcard h2{margin:.6rem 0 .4rem;font-family:var(--sans);font-size:1.3rem;line-height:1.3;padding:0;border:0}
.lockcard h2::before{display:none}
.lockcard p{margin:0 0 1.1rem;font-size:.98rem;line-height:1.6;color:var(--text-dim)}
.lockform{display:flex;flex-wrap:wrap;gap:.6rem .8rem;align-items:center}
.lockform input[type="password"]{flex:1 1 13rem;min-width:0;padding:.68rem .9rem;font:inherit;font-size:1rem;color:var(--text);
  background:var(--bg);border:1px solid var(--rule);border-radius:.45rem;outline:0}
.lockform input[type="password"]:focus{border-color:var(--accent);box-shadow:0 0 0 3px var(--accent-wash)}
.lockform .btn[disabled]{opacity:.6;cursor:wait}
.lockform .rem{display:flex;align-items:center;gap:.4rem;flex-basis:100%;font-size:.88rem;color:var(--text-dim);order:3}
.lockform .lockmsg{flex-basis:100%;min-height:1.3em;font-size:.9rem;color:var(--warn);order:4}
.lockwait{display:none;font-size:1rem;color:var(--text-dim)}
.mlm-unlocked .lockcard .lockform,.mlm-unlocked .lockcard p.lp{display:none}
.mlm-unlocked .lockcard .lockwait{display:block}
.lockform .lockmsg.ok{color:var(--accent)}
.lockcard p.lnote{padding:.6rem .85rem;border-left:3px solid var(--accent);background:var(--accent-wash);color:var(--text);border-radius:0 .35rem .35rem 0}
.rail .rlock{font-family:var(--sans);font-size:.8rem;color:var(--text-faint);line-height:1.5;padding:.2rem 0 0 .2rem}

/* ---------- unlock panel on the home page ---------- */
.lockbar{display:flex;flex-wrap:wrap;gap:1rem 1.6rem;align-items:center;margin:-.8rem 0 2rem;padding:1rem 1.2rem;
  background:var(--surface);border:1px solid var(--rule-soft);border-left:4px solid var(--accent);border-radius:.55rem;font-family:var(--sans)}
.lockbar .lbt{flex:1 1 18rem;font-size:.95rem;line-height:1.55;color:var(--text-dim)}
.lockbar .lbt b{color:var(--text)}
.lockbar .lockform{flex:1 1 22rem}
.lockbar .ison{display:none}
.mlm-any .lockbar .ison{display:block;margin-top:.45rem}
.relock{font:inherit;font-size:.88rem;padding:.3rem .8rem;margin-left:.5rem;color:var(--text-dim);background:transparent;border:1px solid var(--rule);border-radius:.4rem;cursor:pointer}
.relock:hover{color:var(--accent);border-color:var(--accent)}
.part li a .lk{padding-top:.15rem}
.lockbar .lkbig{margin:0;padding:0;color:var(--accent)}
.lockbar .lkbig svg{width:1.7rem;height:1.7rem}

/* ---------- copyright and use notice (2026-10-10) ---------- */
.rights{max-width:48rem;padding:1.2rem 1.4rem;background:var(--surface);border:1px solid var(--rule-soft);border-left:4px solid var(--text-faint);
  border-radius:.55rem;font-family:var(--sans);font-size:.92rem;line-height:1.7;color:var(--text-dim)}
.rights p{margin:0 0 .6rem}
.rights p:last-child{margin-bottom:0}
.rights .rt-c{font-weight:600;color:var(--text)}
#rights{border-bottom:0}