/* Topic navigation and readable chapter dividers, shared across landing pages. */
.po-guide{padding:64px 0;background:#eee8f5;scroll-margin-top:16px}
.po-guide-heading{display:grid;grid-template-columns:1fr 1fr;gap:48px;margin-bottom:30px}
.po-guide h2{font-size:clamp(28px,3.1vw,42px);line-height:1.15;letter-spacing:-.035em;margin:18px 0 0;max-width:22ch}
.po-guide p{font-size:17px;line-height:1.7;color:#514957;margin:0}
.po-proof-link{display:inline-block;margin-top:15px;font-weight:600;text-underline-offset:4px}
.po-topics{display:grid;grid-template-columns:repeat(4,minmax(0,1fr));gap:10px}
.po-topics a{display:flex;align-items:center;gap:10px;padding:15px 14px;min-height:62px;border:1px solid #1c1f2d26;border-radius:7px;background:#fffdf9;color:#1c1f2d;transition:background .15s,border-color .15s;text-decoration:none}
.po-topics a:hover{background:#fceae3;border-color:#ad6649}
.po-topics a>span{font-size:12px;color:#786c80;font-variant-numeric:tabular-nums}
.po-topics b{font-size:14px;line-height:1.4;font-weight:600;overflow-wrap:anywhere;hyphens:auto}
.po-topics i{margin-left:auto;font-style:normal;color:#8d492e}
.po-topics a:focus-visible,.po-proof-link:focus-visible{outline:3px solid #a84e2a;outline-offset:4px}
[data-page-chapter]{scroll-margin-top:16px}
.po-guide~section[id],.rv-differences-full section[id]{scroll-margin-top:16px}
/* Explicit section surfaces also override the legacy IFC page theme. */
.rd-site main [data-section-surface="mint"]{background:#e5eee8!important}
.rd-site main [data-section-surface="peach"]{background:#fceae3!important}
.rd-site main [data-section-surface="lilac"]{background:#eee8f5!important}
.rd-site main .po-band>section{background:transparent}
.rd-site .po-chapter-label{display:flex;align-items:center;gap:14px;font-size:14px;line-height:1.4;letter-spacing:.045em;text-transform:uppercase;font-weight:600;margin-bottom:24px;white-space:normal}
.po-chapter-number{display:inline-flex;align-items:center;justify-content:center;flex:0 0 42px;min-height:42px;border:1px solid currentColor;border-radius:6px;font-size:19px;font-weight:600;letter-spacing:0;font-variant-numeric:tabular-nums}
@media(max-width:1050px){.po-topics{grid-template-columns:repeat(3,minmax(0,1fr))}}
@media(max-width:760px){.po-guide{padding:42px 0}.po-guide-heading{grid-template-columns:1fr;gap:22px}.po-topics{grid-template-columns:repeat(2,minmax(0,1fr))}.po-topics a{padding:12px 10px;gap:7px}.po-topics b{font-size:13px}.po-topics i{display:none}.rd-site .po-chapter-label{font-size:13px;gap:12px}.po-guide h2{max-width:none}}
@media(prefers-reduced-motion:reduce){.po-topics a{transition:none}}