/* * Cube Student · canonical sidebar — shared visual rules * * Per-page CSS still controls the sidebar's gradient, brand block, and * footer row. This stylesheet adds only the cross-page behavior the * canonical sidebar needs: * 1. A hover/focus tooltip for collapsed-state nav items, driven by * data-tooltip set by cube-student-canonical-sidebar.js. The tooltip * is rendered as #kGlobalTooltip / #kGlobalTooltipArrow elements * attached directly to by cube-student-shell.js — same DOM * pattern Tetrahedron uses (tetra-shell-v2.css / tetra-shell-v2.js). * We mirror Tetra's styles here so the look matches across portals. * 2. A safe collapsed-state alignment for nav anchors so labels can * disappear without the row shifting. * * Earlier versions of this stylesheet shipped a ::after pseudo-tooltip * positioned absolutely inside the sidebar. That tooltip clipped behind * sibling cards/topbars whenever an ancestor created a new stacking * context (transform/filter/will-change) or set overflow:hidden, no * matter the z-index. Switching to the body-attached, position:fixed * #kGlobalTooltip pattern with z-index:2147483647 makes the tooltip * always sit above every other portal surface. * * Several Cube Student pages still carry the legacy `body.sidebar-collapsed * .nav a:hover::after { content: attr(data-tooltip); ... }` block in their * per-page