/* Protocol Insights — "Broadsheet" design system (viết mới từ đầu, 2026-10-02).
   Hướng: editorial-longform · centered-masthead · wide-with-margin-notes · horizontal-list · sharp-0 · warm-paper · airy · black-white */
@font-face{font-family:"Fraunces";src:url(/assets/fonts/fraunces-latin-wght-normal.woff2) format("woff2");font-weight:300 900;font-style:normal;font-display:swap}
@font-face{font-family:"Fraunces";src:url(/assets/fonts/fraunces-latin-wght-italic.woff2) format("woff2");font-weight:300 900;font-style:italic;font-display:swap}
@font-face{font-family:"Source Serif 4";src:url(/assets/fonts/source-serif-4-latin-wght-normal.woff2) format("woff2");font-weight:300 800;font-style:normal;font-display:swap}
@font-face{font-family:"Source Serif 4";src:url(/assets/fonts/source-serif-4-latin-wght-italic.woff2) format("woff2");font-weight:300 800;font-style:italic;font-display:swap}
@font-face{font-family:"IBM Plex Mono";src:url(/assets/fonts/ibm-plex-mono-latin-400-normal.woff2) format("woff2");font-weight:400;font-display:swap}
@font-face{font-family:"IBM Plex Mono";src:url(/assets/fonts/ibm-plex-mono-latin-500-normal.woff2) format("woff2");font-weight:500;font-display:swap}

:root{
  --paper:#F4EFE6;--paper-2:#EBE3D5;--paper-3:#E2D8C6;--ink:#1B1714;--ink-2:#4B433B;--ink-3:#6E655A;
  --rule:#1B1714;--rule-soft:#CDBFA9;--ox:#8E1B2E;--ox-soft:#F0DCDA;--ochre:#9A6B12;--ochre-soft:#F1E3C2;--sel:#E9C9C4;
  --serif-d:"Fraunces",Georgia,"Times New Roman",serif;--serif:"Source Serif 4",Georgia,"Times New Roman",serif;
  --mono:"IBM Plex Mono",ui-monospace,Menlo,Consolas,monospace;
  --wrap:1240px;--gut:clamp(16px,4vw,40px);--measure:680px;
  color-scheme:light;
}
@media (prefers-color-scheme:dark){:root:not([data-theme="light"]){
  --paper:#16120F;--paper-2:#201A16;--paper-3:#2A231D;--ink:#EDE6DA;--ink-2:#C2B8A9;--ink-3:#9C9283;
  --rule:#EDE6DA;--rule-soft:#43392F;--ox:#E3798A;--ox-soft:#3A1E22;--ochre:#E0B25A;--ochre-soft:#3A2E17;--sel:#5A2A31;color-scheme:dark}}
:root[data-theme="dark"]{
  --paper:#16120F;--paper-2:#201A16;--paper-3:#2A231D;--ink:#EDE6DA;--ink-2:#C2B8A9;--ink-3:#9C9283;
  --rule:#EDE6DA;--rule-soft:#43392F;--ox:#E3798A;--ox-soft:#3A1E22;--ochre:#E0B25A;--ochre-soft:#3A2E17;--sel:#5A2A31;color-scheme:dark}

*,*::before,*::after{box-sizing:border-box}
html{-webkit-text-size-adjust:100%;text-size-adjust:100%}
body{margin:0;background:var(--paper);color:var(--ink);font-family:var(--serif);font-size:18px;line-height:1.6;font-optical-sizing:auto;
  overflow-wrap:break-word}
::selection{background:var(--sel)}
img,svg{max-width:100%;height:auto}
a{color:inherit;text-decoration-color:var(--ox);text-decoration-thickness:1px;text-underline-offset:3px}
a:hover{color:var(--ox)}
:focus-visible{outline:2px solid var(--ox);outline-offset:3px}
.wrap{max-width:var(--wrap);margin:0 auto;padding:0 var(--gut)}
.sr{position:absolute!important;width:1px;height:1px;overflow:hidden;clip:rect(0 0 0 0);white-space:nowrap}
.skip{position:absolute;left:-999px;top:8px;background:var(--ink);color:var(--paper);padding:8px 14px;z-index:99}
.skip:focus{left:8px}
.mono,.kicker,.label{font-family:var(--mono);font-size:12.5px;letter-spacing:.09em;text-transform:uppercase;font-weight:500}
.kicker{color:var(--ox)}
.kicker a{text-decoration:none}
.muted{color:var(--ink-3)}
hr.dbl,.dbl-top{border:0;border-top:3px double var(--rule)}

/* ---------- masthead (centered) ---------- */
.strip{border-bottom:1px solid var(--rule-soft);font-family:var(--mono);font-size:12px;letter-spacing:.06em;color:var(--ink-2)}
.strip .wrap{display:flex;align-items:center;justify-content:space-between;gap:12px;min-height:40px}
.strip-tools{display:flex;align-items:center;gap:6px}
.strip a{text-decoration:none}
.tbtn{display:inline-flex;align-items:center;gap:8px;background:none;border:1px solid transparent;color:inherit;font:inherit;padding:6px 8px;cursor:pointer;text-decoration:none;letter-spacing:.06em}
.tbtn:hover{border-color:var(--rule-soft);color:var(--ink)}
.tbtn kbd{font-family:var(--mono);font-size:11px;border:1px solid var(--rule-soft);padding:0 5px;color:var(--ink-3)}
.tbtn svg{width:16px;height:16px}
.masthead{text-align:center;padding:26px 0 14px}
.masthead .brand{display:inline-block;color:var(--ink);text-decoration:none}
.masthead .brand svg{width:min(430px,78vw);height:auto;display:block}
.masthead .motto{margin:8px 0 0;font-style:italic;color:var(--ink-2);font-size:16px}
.secnav{border-top:1px solid var(--rule);border-bottom:3px double var(--rule)}
.secnav ul{list-style:none;margin:0 auto;padding:0;display:flex;flex-wrap:wrap;justify-content:center;max-width:var(--wrap)}
.secnav li{display:flex}
.secnav a{display:block;padding:11px 12px;font-family:var(--mono);font-size:12px;letter-spacing:.08em;text-transform:uppercase;text-decoration:none;font-weight:500}
.secnav a[aria-current]{color:var(--ox);box-shadow:inset 0 -2px 0 var(--ox)}
.secnav li.sep{width:1px;background:var(--rule-soft);margin:10px 4px}
.mnav{display:none}
@media (max-width:860px){
  .strip .tagline{display:none}
  .masthead{padding:18px 0 10px}.masthead .motto{font-size:14px}
  .secnav{display:none}
  .mnav{display:block;border-top:1px solid var(--rule);border-bottom:3px double var(--rule)}
  .mnav summary{list-style:none;cursor:pointer;padding:11px var(--gut);font-family:var(--mono);font-size:12.5px;letter-spacing:.09em;text-transform:uppercase;display:flex;justify-content:space-between;align-items:center}
  .mnav summary::-webkit-details-marker{display:none}
  .mnav summary::after{content:"+";font-size:18px}
  .mnav[open] summary::after{content:"−"}
  .mnav ul{list-style:none;margin:0;padding:0 var(--gut) 12px;columns:2;column-gap:20px}
  .mnav a{display:block;padding:9px 0;border-top:1px solid var(--rule-soft);text-decoration:none;font-size:17px;break-inside:avoid}
}

/* ---------- risk ribbon ---------- */
.ribbon{background:var(--ochre-soft);color:var(--ink);font-size:14.5px;border-bottom:1px solid var(--rule-soft)}
.ribbon .wrap{padding-top:8px;padding-bottom:8px;text-align:center}
.ribbon b{font-family:var(--mono);font-size:11.5px;letter-spacing:.1em;text-transform:uppercase;color:var(--ochre);margin-right:6px}

/* ---------- breadcrumb ---------- */
.crumbs ol{list-style:none;margin:0;padding:22px 0 0;display:flex;flex-wrap:wrap;gap:6px;font-family:var(--mono);font-size:12px;letter-spacing:.06em;text-transform:uppercase;color:var(--ink-3)}
.crumbs li+li::before{content:"/";margin-right:6px;color:var(--rule-soft)}
.crumbs a{text-decoration:none}

/* ---------- home: big typographic hero ---------- */
.bighero{padding-top:clamp(36px,7vw,84px);padding-bottom:clamp(8px,2vw,20px)}
.bighero h1{font-family:var(--serif-d);font-weight:640;font-size:clamp(46px,9.2vw,124px);line-height:.95;letter-spacing:-.025em;margin:0 0 0 -.04em;max-width:15ch}
.bighero h1 em{font-style:italic;font-weight:560;color:var(--ox)}
.hero-cols{display:grid;grid-template-columns:1.25fr 1fr 1fr;gap:0;margin-top:clamp(28px,4vw,48px);border-top:1px solid var(--rule)}
.hero-cols>div{padding:20px 28px 4px 0}
.hero-cols>div+div{padding-left:28px;border-left:1px solid var(--rule-soft)}
.hero-cols p.lede{font-size:21px;line-height:1.5;margin:0}
.hero-cols .label{display:block;margin-bottom:10px;color:var(--ink-3)}
.searchbox{display:flex;border:1px solid var(--rule);background:var(--paper)}
.searchbox input{flex:1;min-width:0;border:0;background:transparent;font:inherit;font-size:17px;padding:12px 14px;color:var(--ink)}
.searchbox button{border:0;border-left:1px solid var(--rule);background:var(--ink);color:var(--paper);font-family:var(--mono);font-size:12px;letter-spacing:.08em;text-transform:uppercase;padding:0 16px;cursor:pointer}
.chips{display:flex;flex-wrap:wrap;gap:6px 14px;margin-top:12px;font-size:15.5px}
.chips a{font-style:italic}
.pathlist{list-style:none;margin:0;padding:0;counter-reset:p}
.pathlist li{counter-increment:p;display:grid;grid-template-columns:34px 1fr;gap:4px;padding:7px 0;border-bottom:1px solid var(--rule-soft)}
.pathlist li::before{content:counter(p,decimal-leading-zero);font-family:var(--mono);font-size:12px;color:var(--ox);padding-top:5px}
.pathlist a{text-decoration:none;font-size:17px}
.stats{display:flex;flex-wrap:wrap;gap:4px 22px;margin-top:16px;font-family:var(--mono);font-size:12px;letter-spacing:.05em;color:var(--ink-3)}
.stats b{color:var(--ink);font-weight:500}
@media (max-width:900px){.hero-cols{grid-template-columns:1fr}.hero-cols>div,.hero-cols>div+div{padding:18px 0;border-left:0;border-top:1px solid var(--rule-soft)}}

/* ---------- section heads ---------- */
.band{padding-top:clamp(34px,5vw,60px)}
.band-head{display:flex;align-items:baseline;justify-content:space-between;gap:16px;border-bottom:1px solid var(--rule);padding-bottom:10px;margin-bottom:6px}
.band-head h2{font-family:var(--serif-d);font-weight:620;font-size:clamp(26px,3.2vw,36px);letter-spacing:-.012em;margin:0;line-height:1.1}
.band-head h2 em{color:var(--ox)}
.band-head a{font-family:var(--mono);font-size:12px;letter-spacing:.08em;text-transform:uppercase;text-decoration:none;white-space:nowrap}

/* ---------- horizontal-list cards ---------- */
.rows{list-style:none;margin:0;padding:0}
.row{display:grid;grid-template-columns:200px 1fr;gap:22px;padding:20px 0;border-bottom:1px solid var(--rule-soft);align-items:start}
.row .ph{display:block;aspect-ratio:3/2;overflow:hidden;background:var(--paper-3)}
.row .ph img{width:100%;height:100%;object-fit:cover;display:block}
.row h3{font-family:var(--serif-d);font-weight:600;font-size:23px;line-height:1.18;letter-spacing:-.008em;margin:4px 0 6px}
.row h3 a{text-decoration:none}
.row h3 a:hover{text-decoration:underline}
.row p{margin:0;color:var(--ink-2);font-size:16.5px;line-height:1.5}
.row .meta{margin-top:8px;font-family:var(--mono);font-size:11.5px;letter-spacing:.06em;text-transform:uppercase;color:var(--ink-3)}
.row.lead{grid-template-columns:1.15fr 1fr;gap:30px;padding:24px 0 26px}
.row.lead h3{font-size:clamp(28px,3.4vw,40px);line-height:1.06}
.row.lead p{font-size:18.5px}
.row.noimg{grid-template-columns:1fr}
.diff{display:inline-block;border:1px solid currentColor;padding:0 6px;margin-left:8px;font-size:10.5px;color:var(--ochre)}
.two-col{display:grid;grid-template-columns:1fr 1fr;gap:0 44px}
.three-col{display:grid;grid-template-columns:repeat(3,1fr);gap:0 36px}
.split{display:grid;grid-template-columns:minmax(0,1.7fr) minmax(0,1fr);gap:0 48px}
.split>aside{border-left:1px solid var(--rule-soft);padding-left:32px}
@media (max-width:900px){.two-col,.three-col,.split{grid-template-columns:1fr}.split>aside{border-left:0;padding-left:0}}
@media (max-width:640px){.row{grid-template-columns:104px 1fr;gap:14px;padding:16px 0}.row h3{font-size:19px}.row p{font-size:15.5px}
  .row.lead{grid-template-columns:1fr}.row.lead h3{font-size:28px}.row .hide-sm{display:none}}

/* numbered text list (tools, glossary teasers) */
.numlist{list-style:none;margin:0;padding:0;counter-reset:n}
.numlist li{counter-increment:n;padding:14px 0 14px 44px;border-bottom:1px solid var(--rule-soft);position:relative}
.numlist li::before{content:counter(n,decimal-leading-zero);position:absolute;left:0;top:17px;font-family:var(--mono);font-size:12px;color:var(--ox)}
.numlist a{font-family:var(--serif-d);font-weight:600;font-size:20px;text-decoration:none;line-height:1.2}
.numlist p{margin:4px 0 0;color:var(--ink-2);font-size:15.5px;line-height:1.45}

/* section directory (home & /learn/) */
.dir{display:grid;grid-template-columns:repeat(3,1fr);border-top:1px solid var(--rule)}
.dir a{display:block;padding:20px 22px 22px 0;border-bottom:1px solid var(--rule-soft);text-decoration:none}
.dir a:nth-child(3n+2),.dir a:nth-child(3n){padding-left:22px;border-left:1px solid var(--rule-soft)}
.dir .n{font-family:var(--mono);font-size:12px;color:var(--ox);letter-spacing:.06em}
.dir h3{font-family:var(--serif-d);font-weight:620;font-size:25px;margin:6px 0 4px;line-height:1.12}
.dir p{margin:0;color:var(--ink-2);font-size:15.5px;line-height:1.45}
.dir a:hover h3{color:var(--ox)}
@media (max-width:900px){.dir{grid-template-columns:1fr 1fr}.dir a:nth-child(n){padding-left:0;border-left:0}.dir a:nth-child(2n){padding-left:18px;border-left:1px solid var(--rule-soft)}}
@media (max-width:560px){.dir{grid-template-columns:1fr}.dir a:nth-child(2n){padding-left:0;border-left:0}}

/* glossary letters strip */
.letters{display:flex;flex-wrap:wrap;gap:0;border-top:1px solid var(--rule);border-left:1px solid var(--rule-soft)}
.letters a,.letters span{flex:1 0 44px;text-align:center;padding:10px 0;border-right:1px solid var(--rule-soft);border-bottom:1px solid var(--rule-soft);font-family:var(--serif-d);font-size:21px;font-weight:600;text-decoration:none}
.letters span{color:var(--rule-soft)}
.letters a:hover{background:var(--ink);color:var(--paper)}

/* newsletter panel */
.letter-box{border:1px solid var(--rule);padding:26px 28px;display:grid;grid-template-columns:1fr 1fr;gap:24px;align-items:center;background:var(--paper-2)}
.letter-box h2{font-family:var(--serif-d);font-weight:620;font-size:30px;margin:0 0 6px;line-height:1.1}
.letter-box p{margin:0;color:var(--ink-2);font-size:16px}
.letter-box form{display:flex;gap:0;border:1px solid var(--rule);background:var(--paper)}
.letter-box input{flex:1;min-width:0;border:0;background:transparent;font:inherit;font-size:16px;padding:12px 14px;color:var(--ink)}
.letter-box button{border:0;background:var(--ox);color:#fff;font-family:var(--mono);font-size:12px;letter-spacing:.08em;text-transform:uppercase;padding:0 16px;cursor:pointer}
@media (max-width:760px){.letter-box{grid-template-columns:1fr;padding:20px}}

/* ---------- hub ---------- */
.hubhead{padding-top:28px;padding-bottom:26px;border-bottom:1px solid var(--rule)}
.hubhead h1{font-family:var(--serif-d);font-weight:640;font-size:clamp(44px,7.4vw,96px);line-height:.98;letter-spacing:-.025em;margin:10px 0 14px}
.hubhead .dek{font-size:21px;line-height:1.5;color:var(--ink-2);max-width:60ch;margin:0}
.hubhead .counts{margin-top:14px}
.coming{color:var(--ink-3);font-style:italic}

/* ---------- article (wide-with-margin-notes) ---------- */
.art-head{display:grid;grid-template-columns:200px minmax(0,var(--measure)) 1fr;gap:0 40px;padding-top:18px;padding-bottom:22px}
.art-head>.ah{grid-column:2/4}
.art-head h1{font-family:var(--serif-d);font-weight:640;font-size:clamp(38px,5.4vw,66px);line-height:1.02;letter-spacing:-.02em;margin:12px 0 14px;max-width:18ch}
.art-head .dek{font-size:22px;line-height:1.45;font-style:italic;color:var(--ink-2);margin:0;max-width:44ch}
.byline{display:flex;flex-wrap:wrap;gap:6px 18px;margin-top:18px;padding-top:12px;border-top:1px solid var(--rule-soft);font-family:var(--mono);font-size:12px;letter-spacing:.05em;color:var(--ink-3);text-transform:uppercase}
.byline b{color:var(--ink);font-weight:500}
.leadfig{margin:0 0 6px;display:grid;grid-template-columns:200px minmax(0,1fr);gap:0 40px}
.leadfig>div{grid-column:2}
.leadfig img{width:100%;height:auto;display:block;aspect-ratio:16/9;object-fit:cover;background:var(--paper-3)}
.credit{font-family:var(--mono);font-size:11px;line-height:1.5;letter-spacing:.02em;color:var(--ink-3);margin-top:6px}
.credit a{color:inherit}
.art{display:grid;grid-template-columns:200px minmax(0,var(--measure)) minmax(0,1fr);gap:0 40px;align-items:start;padding-bottom:40px}
.rail{grid-column:1;grid-row:1/span 40;position:sticky;top:18px;padding-top:26px}
.rail .label{display:block;color:var(--ink-3);padding-bottom:8px;border-bottom:1px solid var(--rule);margin-bottom:6px}
.toc ol{list-style:none;margin:0;padding:0;counter-reset:t}
.toc li{counter-increment:t;border-bottom:1px solid var(--rule-soft)}
.toc a{display:grid;grid-template-columns:24px 1fr;padding:7px 0;font-size:14.5px;line-height:1.35;text-decoration:none;color:var(--ink-2)}
.toc a::before{content:counter(t);font-family:var(--mono);font-size:11px;color:var(--ox);padding-top:2px}
.toc a.on,.toc a:hover{color:var(--ink)}
.rail .facts{margin-top:22px;font-family:var(--mono);font-size:11.5px;letter-spacing:.04em;color:var(--ink-3);line-height:1.8}
.rail .facts b{color:var(--ink);font-weight:500}
.mtoc{display:none}
.blk{grid-column:2;min-width:0}
.mar{grid-column:3;min-width:0;font-size:15px;line-height:1.5;color:var(--ink-2)}
.mar .note{border-top:2px solid var(--ox);padding-top:8px;margin-top:54px}
@media (max-width:860px){.mar .note{margin-top:8px}}
.mar .note .label{color:var(--ox);display:block;margin-bottom:4px}
.short{border-top:3px double var(--rule);border-bottom:1px solid var(--rule);padding:16px 0 6px;margin:26px 0 8px}
.short .label{color:var(--ox)}
.short ul{margin:10px 0 0;padding-left:20px}
.short li{margin:0 0 8px;font-size:17.5px}
.answer{font-size:21px;line-height:1.55;margin:26px 0 0}
.answer>p:first-child::first-letter{font-family:var(--serif-d);font-weight:700;float:left;font-size:4.2em;line-height:.82;padding:6px 10px 0 0;color:var(--ox)}
.prose h2{font-family:var(--serif-d);font-weight:620;font-size:clamp(27px,3vw,34px);line-height:1.15;letter-spacing:-.012em;margin:46px 0 12px;scroll-margin-top:16px}
.prose h3{font-family:var(--serif-d);font-weight:600;font-size:22px;line-height:1.25;margin:28px 0 8px}
.prose p,.prose li{font-size:18.5px;line-height:1.68}
.prose ul,.prose ol{padding-left:22px}
.prose li{margin:0 0 6px}
.prose a{text-decoration-color:var(--ox)}
.prose strong{font-weight:650}
.tbl{overflow-x:auto;margin:22px 0;border-top:2px solid var(--rule);border-bottom:2px solid var(--rule)}
.tbl table{border-collapse:collapse;width:100%;font-size:16px;line-height:1.45;min-width:460px}
.tbl th{font-family:var(--mono);font-size:11.5px;letter-spacing:.07em;text-transform:uppercase;font-weight:500;text-align:left;padding:10px 12px 8px;border-bottom:1px solid var(--rule);vertical-align:bottom}
.tbl td{padding:10px 12px;border-bottom:1px solid var(--rule-soft);vertical-align:top}
.tbl tr:last-child td{border-bottom:0}
@media (max-width:640px){
  .tbl{overflow:visible}.tbl table{min-width:0}.tbl thead{position:absolute;width:1px;height:1px;overflow:hidden;clip:rect(0 0 0 0)}
  .tbl tr{display:block;padding:10px 0;border-bottom:1px solid var(--rule-soft)}.tbl tr:last-child{border-bottom:0}
  .tbl td{display:grid;grid-template-columns:minmax(92px,36%) 1fr;gap:10px;border:0;padding:4px 0}
  .tbl td::before{content:attr(data-label);font-family:var(--mono);font-size:10.5px;letter-spacing:.06em;text-transform:uppercase;color:var(--ink-3);padding-top:4px}
  .tbl td:first-child{font-weight:650}
  .tbl td[data-label=""]{display:block;font-family:var(--serif-d);font-size:17px;padding-top:2px}.tbl td[data-label=""]::before{display:none}
}
.tbl caption{caption-side:bottom;text-align:left;font-family:var(--mono);font-size:11px;color:var(--ink-3);padding:6px 0}
aside.note,aside.warn,aside.example{margin:24px 0;padding:14px 18px 6px;border-left:3px solid var(--ink);background:var(--paper-2)}
aside.warn{border-left-color:var(--ox);background:var(--ox-soft)}
aside.example{border-left-color:var(--ochre);background:var(--ochre-soft)}
aside.note::before,aside.warn::before,aside.example::before{display:block;font-family:var(--mono);font-size:11.5px;letter-spacing:.1em;text-transform:uppercase;font-weight:500;margin-bottom:6px}
aside.note::before{content:"Note"}
aside.warn::before{content:"Watch out";color:var(--ox)}
aside.example::before{content:"Worked example";color:var(--ochre)}
aside.note p,aside.warn p,aside.example p,aside.note li,aside.warn li,aside.example li{font-size:17px;line-height:1.6}
ol.steps{list-style:none;padding:0;margin:22px 0;counter-reset:s;border-top:1px solid var(--rule)}
ol.steps>li{counter-increment:s;display:grid;grid-template-columns:52px 1fr;gap:4px;padding:14px 0;border-bottom:1px solid var(--rule-soft);margin:0}
ol.steps>li::before{content:counter(s);font-family:var(--serif-d);font-weight:700;font-size:34px;line-height:1;color:var(--ox)}
ol.steps>li>*{grid-column:2}
ol.steps>li>:first-child{margin-top:0}
.factbox{border:1px solid var(--rule);padding:14px 16px 10px;background:var(--paper)}
.factbox .label{display:block;color:var(--ox);border-bottom:1px solid var(--rule);padding-bottom:8px;margin-bottom:4px}
.factbox dl{margin:0}
.factbox dt{font-family:var(--mono);font-size:11px;letter-spacing:.06em;text-transform:uppercase;color:var(--ink-3);margin-top:10px}
.factbox dd{margin:2px 0 0;font-family:var(--serif-d);font-weight:600;font-size:19px;line-height:1.25;color:var(--ink)}
.factbox dd sup a{font-family:var(--mono);font-size:10px;text-decoration:none;color:var(--ox)}
figure.inl{margin:28px 0}
figure.inl img{width:100%;height:auto;display:block;background:var(--paper-3)}
figure.diagram{margin:28px 0;padding:16px 0 10px;border-top:1px solid var(--rule);border-bottom:1px solid var(--rule)}
figure.diagram svg{display:block;width:100%;height:auto}
figure.diagram .v{display:none}
figure.diagram figcaption{font-family:var(--mono);font-size:11.5px;color:var(--ink-3);margin-top:8px;letter-spacing:.02em}
.faq{margin-top:46px;border-top:3px double var(--rule);padding-top:4px}
.faq h2{margin-top:18px}
.faq .qa{border-bottom:1px solid var(--rule-soft);padding:6px 0 4px}
.faq h3{font-size:21px;margin:14px 0 6px}
.bottomline{margin-top:40px;padding:20px 22px 8px;background:var(--ink);color:var(--paper)}
.bottomline .label{color:var(--ochre-soft)}
.bottomline p{font-size:18.5px;line-height:1.62}
.bottomline a{color:inherit}
.sources{margin-top:40px}
.sources h2{font-family:var(--mono)!important;font-size:13px!important;letter-spacing:.1em;text-transform:uppercase;font-weight:500!important;margin:0 0 6px!important;border-bottom:1px solid var(--rule);padding-bottom:8px}
.sources ol{margin:0;padding:0;list-style:none;counter-reset:c}
.sources li{counter-increment:c;display:grid;grid-template-columns:30px 1fr;font-size:15px!important;line-height:1.5!important;padding:7px 0;border-bottom:1px solid var(--rule-soft);margin:0!important}
.sources li::before{content:"[" counter(c) "]";font-family:var(--mono);font-size:11.5px;color:var(--ox);padding-top:2px}
.sources .grade{font-family:var(--mono);font-size:10.5px;letter-spacing:.06em;text-transform:uppercase;color:var(--ochre);margin-left:6px}
.disclaim{margin-top:28px;font-size:14.5px;color:var(--ink-3);font-style:italic;border-top:1px solid var(--rule-soft);padding-top:12px}
.brandnote{font-family:var(--mono);font-size:10.5px;color:var(--ink-3);margin-top:10px;letter-spacing:.02em}
.logos{display:flex;flex-wrap:wrap;gap:10px;margin:18px 0 0}
.logos span{display:inline-flex;align-items:center;gap:8px;border:1px solid var(--rule-soft);padding:6px 10px 6px 6px;font-family:var(--mono);font-size:12px;background:var(--paper)}
.logos img{width:26px;height:26px;display:block}
.related{margin-top:44px}
@media (max-width:1180px){
  .art,.art-head,.leadfig{grid-template-columns:minmax(0,var(--measure)) minmax(0,1fr);gap:0 36px}
  .art-head>.ah,.leadfig>div{grid-column:1/3}
  .rail{display:none}.mtoc{display:block}
  .blk{grid-column:1}.mar{grid-column:2}
}
@media (max-width:860px){
  .art,.art-head,.leadfig{grid-template-columns:minmax(0,1fr)}
  .art-head>.ah,.leadfig>div,.blk,.mar{grid-column:1}
  .mar{margin:4px 0 6px}
  .art-head .dek{font-size:19px}
  .answer{font-size:19px}
  .prose p,.prose li{font-size:18px}
  figure.diagram .h{display:none}figure.diagram .v{display:block;max-width:420px;margin:0 auto}
}
.mtoc{margin:22px 0 0;border-top:1px solid var(--rule);border-bottom:1px solid var(--rule)}
.mtoc summary{cursor:pointer;padding:10px 0;font-family:var(--mono);font-size:12px;letter-spacing:.09em;text-transform:uppercase;list-style:none;display:flex;justify-content:space-between}
.mtoc summary::-webkit-details-marker{display:none}
.mtoc summary::after{content:"+"}
.mtoc[open] summary::after{content:"−"}
.mtoc ol{margin:0 0 10px;padding-left:22px;font-size:16px}
.mtoc li{padding:3px 0}

/* ---------- tools ---------- */
.calc{border:1px solid var(--rule);margin:26px 0;background:var(--paper)}
.calc-head{background:var(--ink);color:var(--paper);padding:10px 16px;font-family:var(--mono);font-size:12px;letter-spacing:.09em;text-transform:uppercase}
.calc form{display:grid;grid-template-columns:repeat(2,minmax(0,1fr));gap:14px 18px;padding:18px 16px}
.calc label{display:block;font-family:var(--mono);font-size:11.5px;letter-spacing:.06em;text-transform:uppercase;color:var(--ink-2);margin-bottom:5px}
.calc input,.calc select{width:100%;font:inherit;font-size:17px;padding:9px 10px;border:1px solid var(--rule);background:var(--paper);color:var(--ink);border-radius:0}
.calc .full{grid-column:1/-1}
.calc button{grid-column:1/-1;justify-self:start;border:0;background:var(--ox);color:#fff;font-family:var(--mono);font-size:12.5px;letter-spacing:.08em;text-transform:uppercase;padding:12px 18px;cursor:pointer}
.calc-out{border-top:1px solid var(--rule);padding:14px 16px 16px;display:grid;grid-template-columns:repeat(3,minmax(0,1fr));gap:12px;background:var(--paper-2)}
.calc-out div{min-width:0}
.calc-out .k{font-family:var(--mono);font-size:11px;letter-spacing:.06em;text-transform:uppercase;color:var(--ink-3)}
.calc-out .v{font-family:var(--serif-d);font-weight:640;font-size:26px;line-height:1.15;overflow-wrap:anywhere}
.calc-out .full{grid-column:1/-1;font-size:15px;color:var(--ink-2)}
.calc noscript p{margin:0;padding:12px 16px;font-size:15.5px}
@media (max-width:560px){.calc form{grid-template-columns:1fr}.calc-out{grid-template-columns:1fr 1fr}}

/* ---------- trust/static ---------- */
.page{display:grid;grid-template-columns:200px minmax(0,var(--measure));gap:0 40px;padding-bottom:50px}
.page>.blk{grid-column:2}
@media (max-width:1180px){.page{grid-template-columns:minmax(0,var(--measure))}.page>.blk{grid-column:1}}
.form{display:grid;gap:12px;max-width:520px}
.form label{font-family:var(--mono);font-size:11.5px;letter-spacing:.06em;text-transform:uppercase}
.form input,.form textarea{font:inherit;font-size:17px;padding:10px;border:1px solid var(--rule);background:var(--paper);color:var(--ink);border-radius:0;width:100%}
.form button{justify-self:start;border:0;background:var(--ox);color:#fff;font-family:var(--mono);font-size:12.5px;letter-spacing:.08em;text-transform:uppercase;padding:12px 18px;cursor:pointer}

/* ---------- search dialog ---------- */
.sdlg{position:fixed;inset:0;z-index:50;background:rgba(20,16,12,.55);display:none;padding:8vh var(--gut) 0}
.sdlg.open{display:block}
.sdlg .box{max-width:720px;margin:0 auto;background:var(--paper);border:1px solid var(--rule);box-shadow:8px 8px 0 var(--ink)}
.sdlg input{width:100%;border:0;border-bottom:1px solid var(--rule);background:transparent;font-family:var(--serif-d);font-size:26px;padding:16px 18px;color:var(--ink)}
.sdlg input:focus{outline:none}
.sdlg ol{list-style:none;margin:0;padding:0;max-height:60vh;overflow:auto}
.sdlg li a{display:block;padding:12px 18px;border-bottom:1px solid var(--rule-soft);text-decoration:none}
.sdlg li a.on,.sdlg li a:hover{background:var(--paper-2)}
.sdlg li b{display:block;font-family:var(--serif-d);font-weight:600;font-size:18px}
.sdlg li span{font-family:var(--mono);font-size:11px;letter-spacing:.06em;text-transform:uppercase;color:var(--ink-3)}
.sdlg .hint{padding:10px 18px;font-family:var(--mono);font-size:11px;color:var(--ink-3)}

/* ---------- footer ---------- */
.foot{margin-top:60px;border-top:3px double var(--rule);background:var(--paper)}
.foot-top{text-align:center;padding:30px 0 10px}
.foot-top svg{width:260px;height:auto;color:var(--ink)}
.foot-top p{margin:8px auto 0;max-width:62ch;color:var(--ink-2);font-size:15.5px;font-style:italic}
.foot-cols{display:grid;grid-template-columns:repeat(4,1fr);gap:24px;padding:24px 0;border-top:1px solid var(--rule-soft);margin-top:20px}
.foot-cols h2{font-family:var(--mono);font-size:12px;letter-spacing:.1em;text-transform:uppercase;font-weight:500;margin:0 0 8px;color:var(--ox)}
.foot-cols ul{list-style:none;margin:0;padding:0}
.foot-cols li{padding:3px 0;font-size:15.5px}
.foot-cols a{text-decoration:none}
.foot-cols a:hover{text-decoration:underline}
.colophon{border-top:1px solid var(--rule-soft);padding:14px 0 26px;font-family:var(--mono);font-size:11px;line-height:1.7;color:var(--ink-3);letter-spacing:.02em}
@media (max-width:760px){.foot-cols{grid-template-columns:1fr 1fr}}

/* 404 */
.nf{text-align:center;padding-top:70px;padding-bottom:40px}
.nf h1{font-family:var(--serif-d);font-weight:640;font-size:clamp(44px,8vw,96px);margin:10px 0}
@media print{.strip,.secnav,.mnav,.rail,.foot,.sdlg,.ribbon{display:none}}