.nb{white-space:nowrap}
.sr-only{position:absolute;width:1px;height:1px;overflow:hidden;clip:rect(0 0 0 0);white-space:nowrap}
.skip{position:absolute;left:12px;top:-60px;z-index:60;background:var(--ink);color:var(--paper);padding:10px 16px;border-radius:999px;text-decoration:none;font-size:15px;font-weight:600}
.skip:focus{top:calc(10px + env(safe-area-inset-top,0px))}

/* ---- shared sub-page pieces ---- */
.page-head{padding-block:calc(var(--nav-h) + clamp(64px,9vw,128px)) clamp(48px,6vw,88px)}
.page-head h1{font-size:clamp(40px,5.6vw,80px);letter-spacing:-.03em;line-height:1.03;max-width:18ch}
.page-head .lede{margin-top:clamp(18px,2.2vw,28px);max-width:36em;font-size:clamp(19px,1.7vw,23px);line-height:1.5;color:var(--muted)}
.cta-band{min-height:70vh;display:grid;grid-template-rows:1fr auto}
.cta-body{display:grid;gap:28px;justify-items:center;align-content:center;text-align:center;padding-block:clamp(72px,10vw,140px)}
.cta-body h2{font-size:clamp(36px,5vw,64px);max-width:22ch}
.cta-body p{max-width:46em;color:var(--muted)}
.cta-body .btn{min-height:56px;padding-inline:34px;font-size:16px}
.footer{border-top:1px solid var(--line);padding:24px 0 28px;text-align:center;font-size:14px;color:var(--muted)}
.footer a{text-underline-offset:3px}
.nav-links a[aria-current="page"]{opacity:1;background:var(--nline)}
.arrow-link{display:inline-flex;align-items:center;gap:12px;font-size:17px;font-weight:600;text-decoration:none}
.arrow-link svg{width:26px;height:14px;fill:none;stroke:currentColor;stroke-width:1.4;stroke-linecap:round;stroke-linejoin:round;transition:transform .3s ease}
.arrow-link:hover svg{transform:translateX(8px)}
.ph-box{position:relative;border-radius:var(--r-md);background:#D3D5DB;overflow:hidden}
.chapter[data-theme="dark"] .ph-box{background:#2B3048}
.ph-box span{position:absolute;left:14px;bottom:12px;font-size:12px;font-weight:600;letter-spacing:.06em;text-transform:uppercase;color:rgba(10,14,31,.6)}
.chapter[data-theme="dark"] .ph-box span{color:rgba(250,250,248,.62)}
.ph-box.video::after{content:"";position:absolute;left:50%;top:50%;width:64px;height:64px;margin:-32px 0 0 -32px;border-radius:50%;border:1.5px solid currentColor;opacity:.55;background:no-repeat 56% 50%/18px url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' viewBox='0 0 18 18'%3E%3Cpath d='M4 2l12 7-12 7z' fill='%23888'/%3E%3C/svg%3E")}
@media (prefers-reduced-motion:no-preference){
  .js .rv{opacity:0;transform:translateY(24px);transition:opacity .6s cubic-bezier(.2,.7,.2,1),transform .6s cubic-bezier(.2,.7,.2,1);transition-delay:calc(var(--i,0) * 80ms)}
  .js .rv.in{opacity:1;transform:none}
}