:root{--fg:#1f2328;--muted:#5b636e;--bg:#fbfaf7;--card:#fff;--line:#e3e0d8;--accent:#1f6f8b;--accent-soft:#e6f1f5;--warn:#b5532a;--warn-soft:#fdf1ea;--ok:#2f7d4f;--ok-soft:#eaf5ee}
*{box-sizing:border-box}
html{-webkit-text-size-adjust:100%}
body{margin:0;background:var(--bg);color:var(--fg);font-family:-apple-system,BlinkMacSystemFont,"Hiragino Sans","Hiragino Kaku Gothic ProN","Noto Sans JP",sans-serif;font-size:17px;line-height:1.85;letter-spacing:.01em}
a{color:var(--accent)}
.wrap{max-width:720px;margin:0 auto;padding:0 18px}
header.site{border-bottom:1px solid var(--line);background:#fff}
header.site .wrap{display:flex;align-items:center;justify-content:space-between;height:52px}
header.site a.brand{font-weight:700;text-decoration:none;color:var(--fg);font-size:15px}
header.site a.toc{font-size:14px;text-decoration:none}
main{padding:28px 0 40px}
h1{font-size:1.55em;line-height:1.4;margin:.2em 0 .3em}
.chapno{color:var(--accent);font-weight:700;font-size:.85em;letter-spacing:.08em}
.lead{color:var(--muted)}
h2{font-size:1.25em;line-height:1.45;margin:2.2em 0 .6em;padding-bottom:.25em;border-bottom:2px solid var(--accent-soft)}
h3{font-size:1.05em;margin:1.6em 0 .4em}
p{margin:.7em 0}
ul,ol{padding-left:1.4em}
li{margin:.25em 0}
.goals{background:var(--card);border:1px solid var(--line);border-radius:12px;padding:12px 18px}
.goals h2{border:0;margin:.2em 0;font-size:1em}
.term{font-weight:700;background:linear-gradient(transparent 62%,#fde7a8 62%)}
dl.terms{background:var(--card);border:1px solid var(--line);border-radius:12px;padding:10px 16px}
dl.terms dt{font-weight:700;margin-top:.6em}
dl.terms dd{margin:0 0 .3em 0;color:#333}
.box{border-radius:12px;padding:12px 16px;margin:1.2em 0}
.box .t{font-weight:700;margin-bottom:.2em}
.box.law{background:#f4f2ec;border-left:4px solid #a39b84;font-size:.95em}
.box.point{background:var(--warn-soft);border:1px solid #f0c8b3}
.box.point .t{color:var(--warn)}
.box.note{background:var(--accent-soft)}
.formula{background:#fff;border:1px solid var(--line);border-radius:10px;padding:12px;text-align:center;font-size:1.15em;margin:1em 0;overflow-x:auto;font-family:"Times New Roman","Hiragino Mincho ProN",serif}
.frac{display:inline-flex;flex-direction:column;vertical-align:middle;text-align:center;margin:0 .15em}
.frac>span:first-child{border-bottom:1px solid currentColor;padding:0 .2em}
.calc{font-family:"Times New Roman",serif;white-space:nowrap}
.tbl{overflow-x:auto;margin:1em 0}
table{border-collapse:collapse;width:100%;font-size:.92em;background:#fff}
th,td{border:1px solid var(--line);padding:6px 8px;text-align:left;vertical-align:top}
th{background:#f2f0ea}
td.c,th.c{text-align:center}
figure{margin:1.2em 0;text-align:center}
figure svg{max-width:100%;height:auto}
figcaption{font-size:.85em;color:var(--muted);margin-top:.3em}
.pager{display:flex;gap:10px;margin:2.5em 0 1em}
.pager a,.pager span{flex:1;border:1px solid var(--line);border-radius:12px;padding:10px 14px;text-decoration:none;background:#fff;font-size:.9em;line-height:1.5}
.pager .next{text-align:right}
.pager small{display:block;color:var(--muted)}
.pager span{color:#aaa}
.sources{font-size:.85em;color:var(--muted)}
.sources li{word-break:break-all}
footer{border-top:1px solid var(--line);color:var(--muted);font-size:.8em;padding:18px 0 40px}
/* top page */
.hero{padding:10px 0 6px}
.hero h1{font-size:1.7em}
.part{margin-top:1.8em}
.part h2{font-size:1.05em;border:0;margin:0 0 .5em;color:var(--muted)}
.chlist{list-style:none;padding:0;margin:0}
.chlist li{margin:0 0 8px}
.chlist a,.chlist .soon{display:flex;gap:12px;align-items:center;background:#fff;border:1px solid var(--line);border-radius:12px;padding:12px 14px;text-decoration:none;color:var(--fg)}
.chlist .no{flex:0 0 2.2em;height:2.2em;border-radius:50%;background:var(--accent);color:#fff;display:flex;align-items:center;justify-content:center;font-weight:700;font-size:.9em}
.chlist .soon{opacity:.55}
.chlist .soon .no{background:#9aa3ab}
.chlist .ti{font-weight:700;line-height:1.4}
.chlist .sc{display:block;font-size:.8em;color:var(--muted);font-weight:400}
.badge{font-size:.7em;border:1px solid #bbb;border-radius:20px;padding:0 8px;margin-left:6px;color:#777;font-weight:400;white-space:nowrap}
@media (max-width:480px){body{font-size:16px}h1{font-size:1.4em}}
td.c,th.c{white-space:nowrap}
.part h2 small{display:block;font-weight:400;font-size:.8em}

/* law quote items: hanging indent (number column + text column) */
.box.law p{margin:.3em 0 .5em}
ol.law-items{list-style:none;margin:.4em 0 0;padding:0}
ol.law-items>li{display:grid;grid-template-columns:auto 1fr;column-gap:.6em;margin:0 0 .55em}
ol.law-items>li:last-child{margin-bottom:0}
ol.law-items .ln{min-width:1.3em;font-weight:700;color:#6b6350;white-space:nowrap}
ol.law-items .lt{min-width:0}
ol.law-items ol.law-items{margin-top:.35em}
/* stat1 additions */
.box.def{background:#fff;border:1px solid #c9dbe3;border-left:4px solid var(--accent)}
.box.def .t{color:var(--accent)}
.box.example{background:#f6f8f4;border:1px solid #dfe7d8}
.box.example .t{color:var(--ok)}
.math-display{overflow-x:auto;overflow-y:hidden;-webkit-overflow-scrolling:touch;margin:.9em 0;padding:4px 2px;max-width:100%}
.math-display .katex-display{margin:0}
.box .math-display{margin:.6em 0}
.katex{font-size:1.08em}
.math-display .katex{font-size:1.1em}
p .katex,li .katex,dd .katex,td .katex{white-space:nowrap}
.math-display{background:linear-gradient(to right,var(--bg) 30%,rgba(251,250,247,0)),linear-gradient(to left,var(--bg) 30%,rgba(251,250,247,0)) 100% 0,radial-gradient(farthest-side at 0 50%,rgba(0,0,0,.12),transparent),radial-gradient(farthest-side at 100% 50%,rgba(0,0,0,.12),transparent) 100% 0;background-repeat:no-repeat;background-size:24px 100%,24px 100%,10px 100%,10px 100%;background-attachment:local,local,scroll,scroll}
.box .math-display{background:none}
/* shared header with book switcher */
header.site .wrap{display:block;height:auto;padding-top:8px;padding-bottom:6px}
header.site .hrow{display:flex;align-items:center;justify-content:space-between;height:32px}
header.site .books{display:flex;gap:6px;overflow-x:auto;padding:4px 0 2px;-webkit-overflow-scrolling:touch}
header.site .books a.bk{flex:0 0 auto;font-size:13px;text-decoration:none;color:var(--muted);border:1px solid var(--line);border-radius:999px;padding:2px 12px;background:#fff;line-height:1.7}
header.site .books a.bk.on{background:var(--accent);border-color:var(--accent);color:#fff;font-weight:700}
header.site a.toc{border:1px solid var(--accent);border-radius:999px;padding:1px 12px;line-height:1.7}
/* library top */
.booklist{list-style:none;padding:0;margin:1.2em 0}
.booklist li{margin:0 0 12px}
.booklist a{display:block;background:#fff;border:1px solid var(--line);border-radius:14px;padding:14px 16px;text-decoration:none;color:var(--fg)}
.booklist .bt{display:block;font-weight:700;font-size:1.1em;line-height:1.4}
.booklist .bd{display:block;color:var(--muted);font-size:.9em;margin:.2em 0 .5em}
.booklist .bm{display:block;font-size:.85em;color:var(--accent);font-weight:700}
.booklist .bar{display:block;height:6px;background:#eceae4;border-radius:3px;margin-top:6px;overflow:hidden}
.booklist .bar span{display:block;height:100%;background:var(--accent)}