Floating enroll button with a price

One file, zero dependencies, “use client” for visibility. The root is position:fixed at the bottom with safe-area, pointer-events:none; the bar is pointer-events:auto, translateY(100 %)→0 over .55 s on data-show. showAfter is the threshold selector: an IntersectionObserver sets passed once the element is above the viewport; hideNear lists selectors whose intersection (rootMargin -20 % at the bottom) hides the button; hideAtBottom hides it near the page bottom. Without showAfter the button is visible at once. placement=static puts the button in the flow (for previews and docs). The caption shows from 40rem (container query). A hidden bar is aria-hidden with tabIndex=-1 on the link. Palette --vibeui-cta-018-* with light-dark: white and cool grey, an indigo accent, a lime marker for highlights; Unbounded and Inter via <link precedence> from Google Fonts with system fallbacks. tone pins the scheme, accent, ink and background override colours.