:root{--iv-navy:#14213D;--iv-coral:#E4572E;--iv-coral-ink:#B83A16;--iv-paper:#FFFFFF;--iv-mist:#EEF2F7;--iv-ink:#14213D;--iv-soft:#46506A;--iv-rule:#C9D2E0}
*{box-sizing:border-box}
html{-webkit-text-size-adjust:100%}
body.iv-body{margin:0;background:var(--iv-paper);color:var(--iv-ink);font:18px/1.7 Charter,"Iowan Old Style","Bitstream Charter",Georgia,serif;font-variant-numeric:oldstyle-nums}
::selection{background:#F7C9B9;color:var(--iv-navy)}
a{color:var(--iv-navy);text-decoration-color:var(--iv-coral);text-decoration-thickness:1px;text-underline-offset:3px}
a:hover{text-decoration-thickness:2px}
a:focus-visible,button:focus-visible{outline:2px solid var(--iv-coral);outline-offset:3px}
.iv-skip{position:absolute;left:-999px}.iv-skip:focus{left:16px;top:8px;background:#fff;padding:8px;z-index:9}
.iv-mast{background:var(--iv-navy);padding:14px 16px}
.iv-mark{display:inline-flex;align-items:center;gap:10px;color:#fff;text-decoration:none;font-weight:800;font-size:17px;letter-spacing:.01em}
.iv-frame{max-width:1120px;margin:0 auto;padding:0 16px}
.iv-rail{border-bottom:1px solid var(--iv-rule);padding:10px 0;font-size:15px;line-height:1.5}
.iv-rail-h,.iv-toc>p{margin:0 0 4px;font-weight:800;font-size:13px;color:var(--iv-soft)}
.iv-toc>p strong{font-weight:800}
.iv-chapters ol{list-style:none;margin:0;padding:0;display:flex;flex-wrap:wrap;gap:4px 16px}
.iv-chapters a{text-decoration:none}
.iv-chapters a[aria-current]{color:var(--iv-coral-ink);font-weight:800}
.iv-toc{display:none}
.iv-col{min-width:0;max-width:40em;padding-bottom:24px;counter-reset:iv-ch}
.iv-title{font-weight:900;font-size:31px;line-height:1.15;margin:28px 0 14px;letter-spacing:-.015em}
.iv-col h2{font-weight:900;font-size:24px;line-height:1.25;margin:48px 0 10px;position:relative}
.iv-col section>h2:first-child,.iv-col section>h2{counter-increment:iv-ch}
.iv-col section>h2::before{content:counter(iv-ch);display:inline-block;min-width:1.6em;color:var(--iv-coral-ink);font-variant-numeric:lining-nums}
.iv-col h3{font-weight:800;font-size:19px;margin:24px 0 4px}
.iv-lead{font-size:20px;line-height:1.6}
.iv-cite{background:var(--iv-mist);padding:16px 18px;margin:20px 0}
.iv-cite p{margin:0 0 12px}.iv-cite p:last-child{margin:0}
.iv-btn{display:inline-block;background:var(--iv-coral-ink);color:#fff;padding:11px 20px;text-decoration:none;font:700 17px/1.3 Charter,"Iowan Old Style",Georgia,serif;border:0;border-radius:2px;cursor:pointer}
.iv-btn:hover{background:var(--iv-navy)}
.iv-tablewrap{overflow-x:auto;max-width:100%;margin:16px 0}
table{border-collapse:collapse;width:100%;font-size:16px;font-variant-numeric:lining-nums tabular-nums}
caption{text-align:left;font-weight:800;padding:0 0 6px}
th,td{border-bottom:1px solid var(--iv-rule);padding:8px 10px 8px 0;text-align:left;vertical-align:top}
thead th{border-bottom:2px solid var(--iv-navy);font-weight:800}
.iv-src{font-size:14px;color:var(--iv-soft);margin-top:10px;line-height:1.5}
.iv-diagram{margin:20px 0}.iv-diagram svg{width:100%;max-width:440px;height:auto;background:var(--iv-mist)}
figcaption{font-size:14px;color:var(--iv-soft);font-style:italic}
.iv-cta{margin:40px 0;padding:18px 0;border-top:2px solid var(--iv-navy);border-bottom:1px solid var(--iv-rule)}
.iv-cta p{margin:0 0 10px}
.iv-qs li{margin:8px 0}
.iv-crumbs ol{list-style:none;padding:0;margin:18px 0 0;display:flex;flex-wrap:wrap;gap:6px;font-size:14px;color:var(--iv-soft)}
.iv-crumbs li+li:before{content:"›";margin-right:6px}
.iv-disclosure{margin:48px 0 16px;padding:12px 14px;border:1px solid var(--iv-rule);font-size:15px;color:var(--iv-soft)}
.iv-disclosure p{margin:0}
.iv-colophon{max-width:1120px;margin:0 auto;padding:16px;border-top:1px solid var(--iv-navy);font-size:14px;color:var(--iv-soft);line-height:1.5}
.iv-colophon p{margin:4px 0}

.iv-forau{font-size:15px;color:var(--iv-soft);margin:-4px 0 16px}
.iv-col ul,.iv-col ol{padding-left:1.3em}.iv-col li{margin:6px 0}
.iv-pair{display:grid;gap:14px;margin:18px 0}
.iv-photo{margin:18px 0}.iv-pair .iv-photo{margin:0}
.iv-photo img{display:block;width:100%;height:auto;max-height:520px;object-fit:cover;background:var(--iv-mist)}
.iv-photo figcaption{font-style:normal;font-size:13px;margin-top:4px}
.iv-photo-side img{max-height:420px}
@media (max-width:599px){.iv-photo img{max-height:340px}table{font-size:15px}th,td{padding:7px 8px 7px 0}}
/* folded corner slip: this site's own card */
.iv-slips{display:grid;gap:16px;margin:18px 0}
.iv-slip{position:relative;background:var(--iv-mist);border:1px solid var(--iv-rule);padding:16px 44px 16px 18px;box-shadow:0 2px 6px rgba(0,0,0,.08)}
.iv-slip::after{content:"";position:absolute;top:-1px;right:-1px;width:30px;height:30px;background:linear-gradient(225deg,var(--iv-paper) 0 50%,#F3C9BC 50% 100%);box-shadow:-2px 2px 3px rgba(0,0,0,.10)}
.iv-slip p{margin:0}
.iv-slip-what{font-weight:800;font-size:16px;margin-bottom:8px!important;padding-bottom:6px;border-bottom:1px dotted var(--iv-soft)}
.iv-slip-fig{font-weight:900;font-size:24px;line-height:1.2;color:var(--iv-navy);font-variant-numeric:lining-nums tabular-nums;margin-top:8px!important}
.iv-slip-where{font-size:14px;color:var(--iv-soft)}
.iv-col ol.iv-steps{list-style:none;padding:0;display:grid;gap:12px;counter-reset:iv-st}
.iv-steps>li{counter-increment:iv-st;margin:0}
.iv-steps>li::before{content:counter(iv-st);display:inline-block;margin-right:10px;font-weight:900;color:var(--iv-coral-ink);font-variant-numeric:lining-nums}
.iv-cite ul{margin:0 0 12px}.iv-faqcite{margin:0 0 10px}.iv-faqcite p{margin:0 0 8px}
@media (min-width:600px){.iv-pair{grid-template-columns:1fr 1fr}.iv-pair .iv-photo img{height:260px}.iv-slips{grid-template-columns:1fr 1fr}.iv-photo-side{float:right;width:42%;margin:0 0 12px 20px}}
section{clear:both}
@media (min-width:900px){
 .iv-frame{display:grid;grid-template-columns:220px minmax(0,40em);gap:0 72px}
 .iv-rail{border:0;padding:32px 0 0;position:sticky;top:0;align-self:start;max-height:100vh;overflow:auto}
 .iv-chapters ol{display:block}.iv-chapters li{padding:4px 0;border-bottom:1px solid var(--iv-mist)}
 .iv-toc{display:block;margin-top:28px}.iv-toc ol{padding-left:18px;margin:0}.iv-toc li{margin:4px 0}
 .iv-title{font-size:42px;margin-top:40px}
 .iv-col section>h2::before{position:absolute;left:-2.6em;top:0;min-width:0;font-size:30px;line-height:1}
 .iv-colophon{display:grid;grid-template-columns:1fr auto;gap:0 32px}
 .iv-colophon p:last-child{grid-column:1/-1}
}
@media print{.iv-mast,.iv-rail,.iv-noprint,.iv-colophon,.iv-crumbs{display:none}}
/* mobile pass 2026-11-12: phones only, desktop unchanged */
@media (max-width:760px){
 body.iv-body{line-height:1.6;padding-bottom:env(safe-area-inset-bottom)}
 .iv-mast{padding:4px 16px}
 .iv-mark{min-height:44px;min-width:44px}
 .iv-frame{padding:0 18px}
 .iv-rail{padding:4px 0;font-size:14px;position:relative}
 .iv-rail-h{position:absolute;width:1px;height:1px;overflow:hidden;clip:rect(0 0 0 0)}
 .iv-chapters ol{flex-wrap:nowrap;gap:8px;overflow-x:auto;scrollbar-width:none;-webkit-overflow-scrolling:touch}
 .iv-chapters ol::-webkit-scrollbar{display:none}
 .iv-chapters li{flex:0 0 auto}
 .iv-chapters a{display:inline-flex;align-items:center;min-height:44px;min-width:44px;padding:0 6px;white-space:nowrap}
 .iv-crumbs ol{margin:4px 0 0;gap:0 6px;align-items:center}
 .iv-crumbs a{display:inline-flex;align-items:center;min-height:44px;min-width:44px}
 .iv-title{font-size:30px;margin:12px 0 12px}
 .iv-lead{font-size:19px}
 .iv-btn{display:inline-flex;align-items:center;min-height:48px;padding:10px 20px}
 .iv-colo-links{display:flex;flex-wrap:wrap;gap:8px;align-items:center;font-size:14px}
 .iv-colo-links a{font-size:14px;display:inline-flex;align-items:center;min-height:44px;min-width:44px;padding:0 4px}
 .iv-pair{grid-template-columns:1fr 1fr;gap:8px}
 .iv-photo img,.iv-photo-side img{max-height:220px;aspect-ratio:auto}
 .iv-pair .iv-photo img{height:150px;object-fit:cover}
 .iv-photo-side img{height:200px;object-fit:cover}
 .iv-src,.iv-photo figcaption,figcaption,.iv-crumbs ol{font-size:14px}
 .iv-slip-fig{font-size:22px}
 /* tables become labelled cards */
 .iv-tablewrap{overflow:visible}
 .iv-tablewrap table,.iv-tablewrap tbody,.iv-tablewrap tr,.iv-tablewrap td,.iv-tablewrap caption{display:block;width:100%}
 .iv-tablewrap thead{position:absolute;width:1px;height:1px;overflow:hidden;clip:rect(0 0 0 0)}
 .iv-tablewrap table{font-size:16px}
 .iv-tablewrap tr{border:1px solid var(--iv-rule);background:var(--iv-paper);padding:6px 12px;margin:0 0 10px}
 .iv-tablewrap td{border:0;border-bottom:1px dotted var(--iv-rule);padding:6px 0;display:grid;grid-template-columns:40% 1fr;gap:10px}
 .iv-tablewrap td:last-child{border-bottom:0}
 .iv-tablewrap td:first-child{font-weight:800}
 .iv-tablewrap td::before{content:attr(data-label);font-weight:700;font-size:14px;color:var(--iv-soft);line-height:1.5}
}
/* header and footer CTA 2026-11-12 */
.iv-mast{display:flex;align-items:center;flex-wrap:wrap;gap:8px 16px}
.iv-topcta{margin-left:auto;display:inline-flex;align-items:center;min-height:44px;padding:6px 16px;background:var(--iv-coral-ink);color:#fff;text-decoration:none;font:700 15px/1.25 Charter,"Iowan Old Style",Georgia,serif;border-radius:2px}
.iv-topcta:hover{background:#fff;color:var(--iv-navy)}
.iv-footcta{padding:14px 0 16px;margin:0 0 12px;border-bottom:1px solid var(--iv-rule);grid-column:1/-1}
.iv-footcta p:first-child{font-size:17px;color:var(--iv-ink);margin:0 0 10px;max-width:46em}
@media (max-width:760px){
 .iv-mast{padding:4px 16px 8px}
 .iv-topcta{flex:1 0 100%;justify-content:center;margin:0;font-size:15px;padding:4px 12px}
}
/* strip-w1 */
.iv-strip{display:flex;flex-wrap:wrap;align-items:center;gap:8px 14px;margin:1.6em 0;padding:10px 14px;border:1px solid rgba(0,0,0,.18);border-radius:6px;line-height:1.45}
.iv-strip-tag{font-size:14px;letter-spacing:.06em;text-transform:uppercase;font-weight:700}
.iv-strip-text{flex:1 1 260px;margin:0}
.iv-strip-btn{flex:0 0 auto;min-height:44px;display:inline-flex;align-items:center;justify-content:center;white-space:nowrap;margin:0}
@media (max-width:480px){.iv-strip-btn{width:100%}}
header .iv-topcta{white-space:normal;min-height:44px}
/* /strip-w1 */