/* ATMA lesson page — document format (14 blocks).
   REVIEW.md section C: Proposal A (typography, spacing, figure/table framing)
   combined with Proposal C's navigation (progress bar, desktop sidebar,
   phone bottom bar). Do not hand-edit structural class names without also
   updating tools/build.js, which emits the matching HTML. */
:root{
  --paper:#FBF9F4;--ink:#211F1B;--muted:#6B6659;--rule:#E4DECE;--panel:#F2EEE3;
  --indigo:#2B4A87;--indigo-soft:#DEE4F3;--loss:#AC431B;--loss-soft:#F5DED2;--ok:#2C6A42;--ok-soft:#DBEADF;
  --shadow:0 1px 2px rgba(30,29,26,.04),0 6px 16px -8px rgba(30,29,26,.14);
  --shadow-sm:0 1px 3px rgba(30,29,26,.08);
  --radius:8px;--radius-sm:5px;
  --sp-1:4px;--sp-2:8px;--sp-3:14px;--sp-4:20px;--sp-5:28px;--sp-6:40px;
  --chrome-bg:rgba(251,249,244,.92);--chrome-border:#E4DECE;--track:#E9E3D3;
  --sidebar-w:240px;--topbar-h:6px;--bottombar-h:58px;
}
@media (prefers-color-scheme:dark){:root:not([data-theme="light"]){
  --paper:#1A1B1D;--ink:#EDE9DF;--muted:#A6A194;--rule:#34363B;--panel:#232529;
  --indigo:#9AB0EA;--indigo-soft:#28324C;--loss:#E9905F;--loss-soft:#412A1E;--ok:#83C29A;--ok-soft:#20362A;
  --shadow:0 1px 2px rgba(0,0,0,.3),0 8px 20px -10px rgba(0,0,0,.55);--shadow-sm:0 1px 3px rgba(0,0,0,.4);
  --chrome-bg:rgba(26,27,29,.9);--chrome-border:#34363B;--track:#2C2E32;
}}
:root[data-theme="dark"]{
  --paper:#1A1B1D;--ink:#EDE9DF;--muted:#A6A194;--rule:#34363B;--panel:#232529;
  --indigo:#9AB0EA;--indigo-soft:#28324C;--loss:#E9905F;--loss-soft:#412A1E;--ok:#83C29A;--ok-soft:#20362A;
  --shadow:0 1px 2px rgba(0,0,0,.3),0 8px 20px -10px rgba(0,0,0,.55);--shadow-sm:0 1px 3px rgba(0,0,0,.4);
  --chrome-bg:rgba(26,27,29,.9);--chrome-border:#34363B;--track:#2C2E32;
}
*{box-sizing:border-box}
html{scroll-behavior:smooth}
@media (prefers-reduced-motion:reduce){html{scroll-behavior:auto}}
body{margin:0;background:var(--paper);color:var(--ink);font-family:"Literata",Georgia,serif;font-size:17.5px;line-height:1.65;padding-inline:18px;padding-block:var(--topbar-h) 72px;-webkit-font-smoothing:antialiased}
[dir=rtl]{font-family:"Cairo","Noto Naskh Arabic",system-ui,sans-serif;font-size:18.5px;line-height:1.9}
.wrap{max-width:740px;margin:0 auto}
h1,h2,h3,.label,.kicker,.num,table,.btn,summary,figcaption strong,.meta,.notice,.order,.calc,.rule-tag,.ladder div b,.next,.lang{font-family:"Archivo",system-ui,sans-serif}
[dir=rtl] h1,[dir=rtl] h2,[dir=rtl] h3,[dir=rtl] .kicker,[dir=rtl] .num,[dir=rtl] table,[dir=rtl] .btn,[dir=rtl] summary,[dir=rtl] .meta,[dir=rtl] .notice,[dir=rtl] .order,[dir=rtl] .rule-tag,[dir=rtl] .ladder div b,[dir=rtl] .next,[dir=rtl] figcaption strong{font-family:"Cairo",system-ui,sans-serif}
h1{font-size:clamp(29px,5vw,40px);line-height:1.18;font-weight:700;letter-spacing:-.01em;margin:10px 0 14px;text-wrap:balance}
h2{font-size:22px;line-height:1.3;font-weight:700;margin:0 0 12px;text-wrap:balance}
h3{font-size:18px;line-height:1.35;margin:26px 0 8px;font-weight:600}
p{margin:0 0 14px;max-width:66ch}
.kicker{font-size:12px;letter-spacing:.09em;text-transform:uppercase;color:var(--muted);font-weight:600}
[dir=rtl] .kicker{letter-spacing:0;text-transform:none;font-size:14px}
.top{padding-block:26px 24px;border-bottom:1px solid var(--rule)}
.topbar{display:flex;flex-wrap:wrap;justify-content:space-between;align-items:center;gap:8px 12px;margin-bottom:12px}
.topbar-end{display:flex;flex-wrap:wrap;align-items:center;justify-content:flex-end;gap:6px 14px}
.lang a{color:var(--muted);text-decoration:none;font-size:13px;font-weight:700;padding:5px 11px;border-radius:99px;transition:background .15s,color .15s}
.lang a:hover{background:var(--panel)}
.lang a[aria-current]{background:var(--indigo);color:var(--paper)}
.back-links{display:flex;flex-wrap:wrap;gap:14px}
.back{color:var(--indigo);text-decoration:none;font-family:"Archivo",sans-serif;font-size:14px;font-weight:600}
.back:hover{text-decoration:underline}
.lesson-pager{display:flex;justify-content:space-between;gap:12px;margin-block:32px;padding-top:20px;border-top:1px solid var(--rule)}
.pager-link{font-family:"Archivo",sans-serif;font-weight:600;color:var(--indigo);text-decoration:none;font-size:14px}
.pager-link:hover{text-decoration:underline}
.pager-link.disabled{color:var(--muted);cursor:default}
.pager-link.disabled small{font-weight:400}
.top .meta{display:flex;flex-wrap:wrap;gap:9px 20px;font-size:14px;color:var(--muted)}
.notice{margin-top:16px;font-size:13px;color:var(--muted);border:1px dashed var(--rule);padding:10px 14px;border-radius:var(--radius-sm);line-height:1.55}
.order{margin:24px 0 0;background:var(--panel);border-radius:var(--radius);padding:18px 20px;display:grid;grid-template-columns:1fr 1fr;gap:10px 20px;font-size:14px;box-shadow:var(--shadow-sm);border:1px solid var(--rule)}
.order div span{display:block;color:var(--muted);font-size:11px;letter-spacing:.07em;text-transform:uppercase;margin-bottom:2px}
[dir=rtl] .order div span{letter-spacing:0;text-transform:none;font-size:12px}
.order div b{font-weight:600;font-variant-numeric:tabular-nums}
.lesson-hero{margin:24px 0 0;border-radius:var(--radius);overflow:hidden;box-shadow:var(--shadow-sm);border:1px solid var(--rule)}
.lesson-hero img{display:block;width:100%;height:auto}
.lesson-hero figcaption{padding:10px 14px;font-size:12px;color:var(--muted);background:var(--panel)}
.block>div{min-width:0}
.block{display:grid;grid-template-columns:52px 1fr;gap:16px;padding-block:30px;border-bottom:1px solid var(--rule);scroll-margin-top:calc(var(--topbar-h) + 16px)}
.block>.num{font-size:12px;color:var(--muted);font-weight:600;letter-spacing:.05em;padding-top:7px;font-variant-numeric:tabular-nums}
.block>.num small{display:block;font-size:10px;letter-spacing:.06em;text-transform:uppercase;font-weight:500;line-height:1.3;margin-top:3px}
[dir=rtl] .block>.num small{letter-spacing:0;text-transform:none;font-size:11px}
.rule-tag{display:inline-block;font-size:11px;letter-spacing:.08em;text-transform:uppercase;font-weight:700;color:var(--indigo);background:var(--indigo-soft);padding:3px 10px;border-radius:99px;margin:16px 0 8px}
[dir=rtl] .rule-tag{letter-spacing:0;text-transform:none;font-size:13px}
.rule-tag.trap{color:var(--loss);background:var(--loss-soft)}
.rule-tag.real{color:var(--ok);background:var(--ok-soft)}
.calc{font-variant-numeric:tabular-nums;background:var(--panel);border-inline-start:3px solid var(--indigo);border-radius:0 var(--radius-sm) var(--radius-sm) 0;padding:12px 16px;margin:10px 0 16px;font-size:15px;line-height:1.75;overflow-x:auto;unicode-bidi:plaintext;box-shadow:var(--shadow-sm)}
.calc b{color:var(--indigo)}.calc .loss{color:var(--loss)}
figure{margin:18px 0 8px;background:var(--panel);border:1px solid var(--rule);border-radius:var(--radius);padding:14px;box-shadow:var(--shadow-sm)}
figure svg{width:100%;height:auto;display:block}
figcaption{font-size:14px;color:var(--muted);margin-top:10px;line-height:1.5}
figcaption strong{color:var(--ink);font-weight:600}
table{border-collapse:collapse;width:100%;font-size:14px;font-variant-numeric:tabular-nums}
.tablewrap{overflow-x:auto;margin:12px 0 16px;border:1px solid var(--rule);border-radius:var(--radius-sm)}
th,td{text-align:start;padding:9px 12px;border-bottom:1px solid var(--rule);vertical-align:top}
th{font-size:11px;letter-spacing:.06em;text-transform:uppercase;color:var(--muted);font-weight:700;background:var(--panel)}
[dir=rtl] th{letter-spacing:0;text-transform:none;font-size:13px}
tbody tr:last-child td{border-bottom:0}
td.n,th.n{text-align:end}
.plain{background:var(--panel);padding:18px 20px;border-radius:var(--radius);border-inline-start:4px solid var(--indigo)}
.plain p:last-child{margin:0}
details{border:1px solid var(--rule);border-radius:var(--radius);padding:0 18px;margin-top:10px;box-shadow:var(--shadow-sm);transition:box-shadow .15s}
details[open]{box-shadow:var(--shadow)}
summary{cursor:pointer;padding:14px 0;font-weight:700;color:var(--indigo);list-style:none;display:flex;align-items:center;gap:9px}
summary::before{content:"";width:0;height:0;border-inline-start:7px solid currentColor;border-top:5px solid transparent;border-bottom:5px solid transparent;transition:transform .15s}
details[open] summary::before{transform:rotate(90deg)}
[dir=rtl] details[open] summary::before{transform:rotate(-90deg)}
details .body{padding:0 0 16px}
ul,ol{margin:0 0 14px;padding-inline-start:24px}
li{margin-bottom:6px}
.quiz{margin-bottom:24px}
.quiz .opt{display:flex;gap:11px;align-items:flex-start;padding:12px 14px;border:1px solid var(--rule);border-radius:var(--radius-sm);margin-bottom:9px;cursor:pointer;transition:border-color .15s,background .15s,box-shadow .15s}
.quiz .opt:hover{background:var(--panel);box-shadow:var(--shadow-sm)}
.quiz .opt input{margin-top:6px}
.quiz .opt.right{border-color:var(--ok);background:var(--ok-soft);box-shadow:var(--shadow-sm)}
.quiz .opt.wrong{border-color:var(--loss);background:var(--loss-soft);box-shadow:var(--shadow-sm)}
.quiz .why{display:none;font-size:14px;color:var(--muted);margin-top:5px;line-height:1.5}
.quiz.done .why{display:block}
.quiz .opt .k{font-family:"Archivo",sans-serif;font-weight:700;min-width:18px}
.btn{background:var(--indigo);color:var(--paper);border:0;border-radius:var(--radius-sm);padding:10px 18px;font-size:14px;font-weight:700;cursor:pointer;box-shadow:var(--shadow-sm);transition:transform .1s,box-shadow .15s}
.btn:hover{box-shadow:var(--shadow)}
.btn:active{transform:translateY(1px)}
.btn:disabled{cursor:default;opacity:.85}
.btn:focus-visible{outline:2px solid var(--ink);outline-offset:2px}
.ladder{display:grid;grid-template-columns:repeat(4,1fr);gap:12px}
.ladder div{border-top:3px solid var(--indigo);padding-top:9px;font-size:14px}
.ladder div b{display:block;font-size:12px;letter-spacing:.06em;text-transform:uppercase;margin-bottom:4px}
[dir=rtl] .ladder div b{letter-spacing:0;text-transform:none;font-size:13px}
.next{font-size:15px}.next a{color:var(--indigo);font-weight:600}
.cost{border-inline-start:4px solid var(--loss);padding-inline-start:16px}
.clause{border-inline-start:4px solid var(--indigo);background:var(--indigo-soft);padding:12px 16px;border-radius:0 var(--radius-sm) var(--radius-sm) 0;margin:12px 0;font-size:15px;box-shadow:var(--shadow-sm)}
.num-ltr{direction:ltr;unicode-bidi:isolate;font-variant-numeric:tabular-nums}
@media (max-width:560px){
  body{font-size:16.5px}
  .block{grid-template-columns:1fr;gap:8px;padding-block:24px}
  .block>.num{display:flex;gap:8px;align-items:baseline;padding-top:0}
  .block>.num small{margin:0}
  .ladder{grid-template-columns:1fr 1fr}
  .order{grid-template-columns:1fr 1fr;padding:14px 16px}
}
@media (prefers-reduced-motion:reduce){summary::before,.btn,.quiz .opt,details{transition:none}}

/* Course map page */
.map-list{display:flex;flex-direction:column;gap:12px;margin-top:20px}
.map-item{display:flex;justify-content:space-between;align-items:center;gap:14px;padding:16px 18px;border:1px solid var(--rule);border-radius:var(--radius);background:var(--panel);box-shadow:var(--shadow-sm);text-decoration:none;color:var(--ink)}
.map-item:hover{box-shadow:var(--shadow)}
.map-item.disabled{opacity:.55;cursor:default;pointer-events:none}
.map-item .title{font-family:"Archivo",sans-serif;font-weight:700;font-size:15px}
.map-item .sub{font-size:13px;color:var(--muted);margin-top:2px}
.map-item .status{font-family:"Archivo",sans-serif;font-size:11px;letter-spacing:.06em;text-transform:uppercase;font-weight:700;color:var(--indigo);background:var(--indigo-soft);padding:4px 10px;border-radius:99px;white-space:nowrap}
.map-item.disabled .status{color:var(--muted);background:var(--rule)}

/* ---- Proposal C navigation chrome: progress bar, sidebar, bottom nav ---- */
.progress-track{position:fixed;top:0;inset-inline:0;height:var(--topbar-h);background:var(--track);z-index:40}
.progress-fill{height:100%;width:0%;background:var(--indigo);transition:width .1s linear}
[dir=rtl] .progress-fill{margin-inline-start:auto}
.app-shell{max-width:1040px;margin:0 auto;display:block}
.side-nav{display:none}
.side-col{display:none}
.side-nav-link{display:block;padding:7px 10px;border-radius:var(--radius-sm);font-size:13px;color:var(--muted);text-decoration:none;line-height:1.35}
.side-nav-link:hover{background:var(--panel);color:var(--ink)}
.side-nav-link.active{background:var(--indigo-soft);color:var(--indigo);font-weight:700}
.side-nav-num{display:inline-block;min-width:20px;font-variant-numeric:tabular-nums;font-weight:700;margin-inline-end:6px;color:var(--muted)}
.side-nav-link.active .side-nav-num{color:var(--indigo)}
.bottom-nav{position:fixed;bottom:0;inset-inline:0;height:var(--bottombar-h);background:var(--chrome-bg);backdrop-filter:blur(8px);border-top:1px solid var(--chrome-border);display:flex;align-items:center;justify-content:space-between;padding:0 14px;z-index:40;font-family:"Archivo",system-ui,sans-serif}
[dir=rtl] .bottom-nav{font-family:"Cairo",system-ui,sans-serif}
.bottom-nav button{background:none;border:0;color:var(--indigo);font-weight:700;font-size:13px;padding:8px 10px;cursor:pointer;display:flex;align-items:center;gap:6px}
.bottom-nav button:disabled{opacity:.35;cursor:default}
.bottom-nav .bn-label{font-size:11px;color:var(--muted);text-align:center;font-variant-numeric:tabular-nums}
body{padding-bottom:calc(72px + var(--bottombar-h))}
@media (min-width:900px){
  .app-shell{display:grid;grid-template-columns:var(--sidebar-w) 1fr;gap:36px;align-items:start}
  .side-col{display:block;position:sticky;top:calc(var(--topbar-h) + 20px);padding-block:18px 40px;padding-inline:0 8px;max-height:calc(100vh - var(--topbar-h) - 40px);overflow-y:auto;scrollbar-width:thin}
  .side-nav{display:block}
  .course-nav{margin-block-end:22px;padding-block-end:18px;border-block-end:1px solid var(--rule)}
  .course-nav-m{display:none}
  .side-nav-title a{color:inherit;text-decoration:none}
  .side-nav-title a:hover{color:var(--indigo);text-decoration:underline}
  .side-nav-title{font-family:"Archivo",system-ui,sans-serif;font-size:11px;letter-spacing:.08em;text-transform:uppercase;color:var(--muted);font-weight:700;padding:0 10px 10px}
  [dir=rtl] .side-nav-title{letter-spacing:0;text-transform:none;font-size:12px}
  .bottom-nav{display:none}
  body{padding-bottom:72px}
}

/* ---- Course contents (sticky column + mobile <details>), Did you know, account ---- */
.course-nav-sub{font-family:"Archivo",system-ui,sans-serif;font-size:12px;line-height:1.4;color:var(--muted);padding:0 10px 10px}
[dir=rtl] .course-nav-sub{font-family:"Cairo",system-ui,sans-serif;font-size:13px}
.course-nav-list{list-style:none;margin:0;padding:0}
.course-nav-item{display:flex;align-items:baseline;gap:4px;margin:0 0 2px}
.course-nav-link{flex:1;min-width:0;display:flex;align-items:baseline;padding:7px 10px;border-radius:var(--radius-sm);font-size:13px;color:var(--muted);text-decoration:none;line-height:1.35}
a.course-nav-link:hover{background:var(--panel);color:var(--ink)}
.course-nav-link.active{background:var(--indigo-soft);color:var(--indigo);font-weight:700}
.course-nav-link.disabled{cursor:default;opacity:.7}
.course-nav-link.disabled small{display:block;font-size:11px;font-weight:400}
.course-nav-num{flex:none;min-width:20px;font-variant-numeric:tabular-nums;font-weight:700;margin-inline-end:6px;color:var(--muted)}
.course-nav-link.active .course-nav-num{color:var(--indigo)}
.course-nav-title{display:-webkit-box;-webkit-line-clamp:3;line-clamp:3;-webkit-box-orient:vertical;overflow:hidden}
.course-nav-text{min-width:0}
.done-mark{flex:none;min-width:1.2em;text-align:center;font-family:"Archivo",system-ui,sans-serif;font-size:13px;font-weight:700;line-height:1.35;color:var(--ok)}
.course-nav-m{margin:14px 0 0}
.course-nav-m .body{padding-bottom:10px}
.course-nav-map{margin:0 0 8px;font-family:"Archivo",system-ui,sans-serif;font-size:13px}
[dir=rtl] .course-nav-map{font-family:"Cairo",system-ui,sans-serif}
.course-nav-map a{color:var(--indigo);font-weight:600;text-decoration:none}
.course-nav-map a:hover{text-decoration:underline}
.course-nav-m .course-nav-link{padding-inline:4px}

.did-you-know{margin:24px 0 0;padding:16px 20px 14px;background:var(--panel);border:1px solid var(--rule);border-inline-start:4px solid var(--indigo);border-radius:var(--radius);box-shadow:var(--shadow-sm)}
.dyk-eyebrow{display:inline-block;font-family:"Archivo",system-ui,sans-serif;font-size:11px;letter-spacing:.08em;text-transform:uppercase;font-weight:700;color:var(--indigo);background:var(--indigo-soft);padding:3px 10px;border-radius:99px;margin-bottom:10px}
[dir=rtl] .dyk-eyebrow{font-family:"Cairo",system-ui,sans-serif;letter-spacing:0;text-transform:none;font-size:13px}
.dyk-fact{margin:0 0 8px;font-size:16px;line-height:1.6}
.dyk-source{margin:0;font-family:"Archivo",system-ui,sans-serif;font-size:12.5px;line-height:1.5;color:var(--muted)}
[dir=rtl] .dyk-source{font-family:"Cairo",system-ui,sans-serif;font-size:13.5px}

.account-chip{display:inline-flex;flex-wrap:wrap;align-items:center;gap:4px 12px;font-family:"Archivo",system-ui,sans-serif;font-size:13px}
[dir=rtl] .account-chip{font-family:"Cairo",system-ui,sans-serif}
.account-chip[hidden],.lesson-complete[hidden]{display:none}
.account-name{color:var(--muted);max-width:16ch;overflow:hidden;text-overflow:ellipsis;white-space:nowrap}
.account-link{color:var(--indigo);font-weight:600;text-decoration:none}
.account-link:hover{text-decoration:underline}
.account-out{background:none;border:0;padding:0;font:inherit;font-weight:600;color:var(--muted);cursor:pointer}
.account-out:hover{color:var(--ink);text-decoration:underline}
.account-link:focus-visible,.account-out:focus-visible{outline:2px solid var(--indigo);outline-offset:2px;border-radius:2px}
.lesson-complete{display:flex;justify-content:center;margin:-8px 0 32px}
.lesson-complete .btn:disabled{background:var(--ok)}