/* reading-rail v2: dots in the gutter beside the column, labels never over the text */
.rail{display:none}
@media(min-width:1100px){
.rail{--col:62rem;--gut:1.25rem;display:flex;flex-direction:column;position:fixed;top:50%;left:calc(50% + var(--col)/2 + var(--gut));transform:translateY(-50%);z-index:40;margin:0;padding:.4rem 0;max-height:calc(100vh - 7rem)}
.rail::before{content:"";position:absolute;left:calc(.875rem - .5px);top:1.1rem;bottom:1.1rem;width:1px;background:var(--line)}
.rail-dot{position:relative;display:flex;align-items:center;justify-content:center;width:1.75rem;height:1.75rem;text-decoration:none;border-radius:50%}
.rail-dot .dot{width:7px;height:7px;border-radius:50%;background:var(--mut);box-shadow:0 0 0 3px var(--bg);transition:transform .2s,background .2s,box-shadow .2s;flex:none}
.rail-dot:hover .dot,.rail-dot:focus-visible .dot{background:var(--acc);transform:scale(1.25)}
.rail-dot[aria-current=true] .dot{background:var(--acc);transform:scale(1.45);box-shadow:0 0 0 3px var(--bg),0 0 0 4.5px color-mix(in srgb,var(--acc) 38%,transparent)}
.rail-dot:focus-visible{outline:2px solid var(--acc);outline-offset:-1px}
/* narrow gutter: a label is a hover/focus tooltip only, never left on over the text */
.rail-label{position:absolute;right:calc(100% + .3rem);top:50%;transform:translate(6px,-50%);padding:.22rem .65rem;border:1px solid var(--line);border-radius:.5rem;background:var(--bg);color:var(--fg);box-shadow:0 6px 20px rgba(0,0,0,.14);font-size:.82rem;font-weight:600;line-height:1.3;white-space:nowrap;opacity:0;pointer-events:none;transition:opacity .15s,transform .15s}
.rail-dot:hover .rail-label,.rail-dot:focus-visible .rail-label{opacity:1;transform:translate(0,-50%)}
}
/* wide gutter: labels sit outside the column and still appear only on hover or focus */
@media(min-width:1400px){
.rail-label{right:auto;left:calc(100% + .15rem);max-width:calc(50vw - var(--col)/2 - var(--gut) - 3.25rem);overflow:hidden;text-overflow:ellipsis;padding:.1rem .2rem;border-color:transparent;background:transparent;box-shadow:none;color:var(--mut);transform:translate(-4px,-50%)}
.rail-dot:hover .rail-label,.rail-dot:focus-visible .rail-label{color:var(--acc)}
}
@media(prefers-reduced-motion:reduce){.rail .dot,.rail-label{transition:none}}
@media(forced-colors:active){.rail::before{background:CanvasText}.rail-dot .dot{background:CanvasText;box-shadow:none}.rail-dot[aria-current=true] .dot{background:Highlight}.rail-label{border-color:CanvasText}}

.rail{--mut:var(--text-muted);--acc:var(--oak);--fg:var(--text-primary)}