/**
 * Shared chapter-rail styles for all PickBits University tracks.
 *
 * Two render modes (selected by rail.js based on the page):
 *   1. INLINE — the rail sits in a CSS grid alongside .vibe-content (hub pages).
 *      Sticky positioning keeps it pinned while the right pane scrolls.
 *   2. FIXED  — the rail is position:fixed at the left of the viewport on
 *      module-index and lesson pages, where there's no enclosing grid.
 *
 * Both modes share the visual treatment + the collapse/expand UI; only the
 * positioning differs. Per-track palette is set via CSS custom properties
 * on .vibe-rail--<track>.
 */

:root {
    --uni-rail-width: 240px;
    --uni-rail-collapsed-width: 38px;
    --uni-rail-top: 88px;          /* clears the fixed site header */
}

/* Per-track accent palette (cyan / yellow / green) ----------------------- */
.vibe-rail--vibe-coder       { --rail-accent: #00f4ff; --rail-accent-rgb: 0, 244, 255; }
.vibe-rail--vibe-management  { --rail-accent: #ffe600; --rail-accent-rgb: 255, 230, 0; }
.vibe-rail--field-guides     { --rail-accent: #00ff88; --rail-accent-rgb: 0, 255, 136; }

/* INLINE mode (hub pages) ------------------------------------------------- */
.vibe-layout {
    max-width: 1200px;
    margin: 2rem auto 0;
    padding: 0 1rem;
    display: grid;
    grid-template-columns: var(--uni-rail-width) 1fr;
    gap: 2.5rem;
    align-items: start;
}
.vibe-content { min-width: 0; }

.vibe-rail {
    position: sticky;
    top: var(--uni-rail-top);
    align-self: start;
    max-height: calc(100vh - var(--uni-rail-top) - 22px);
    overflow-y: auto;
    scrollbar-width: thin;
    scrollbar-color: rgba(var(--rail-accent-rgb, 0, 244, 255), 0.3) transparent;
}

/* FIXED mode (module-index + lesson pages) -------------------------------- */
.vibe-rail--fixed {
    position: fixed;
    top: var(--uni-rail-top);
    left: 0;
    width: var(--uni-rail-width);
    height: calc(100vh - var(--uni-rail-top) - 12px);
    overflow-y: auto;
    z-index: 90;                   /* below site header (z 1000), above content */
    padding: 0 0.75rem 1rem 1rem;
    background: rgba(10, 10, 20, 0.92);
    backdrop-filter: blur(6px);
    border-right: 1px solid rgba(var(--rail-accent-rgb, 0, 244, 255), 0.15);
}
body.uni-rail-fixed { padding-left: var(--uni-rail-width); transition: padding-left 0.18s ease; }

.vibe-rail::-webkit-scrollbar { width: 6px; }
.vibe-rail::-webkit-scrollbar-thumb {
    background: rgba(var(--rail-accent-rgb, 0, 244, 255), 0.3);
    border-radius: 3px;
}

/* Toggle (collapse/expand) ----------------------------------------------- */
.vibe-rail-toggle {
    position: absolute;
    top: 0.5rem;
    right: 0.5rem;
    width: 26px;
    height: 26px;
    background: transparent;
    border: 1px solid rgba(var(--rail-accent-rgb, 0, 244, 255), 0.3);
    border-radius: 3px;
    color: rgba(var(--rail-accent-rgb, 0, 244, 255), 0.85);
    cursor: pointer;
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 0.8rem;
    z-index: 2;
    transition: all 0.15s;
}
.vibe-rail-toggle:hover {
    background: rgba(var(--rail-accent-rgb, 0, 244, 255), 0.1);
    border-color: rgba(var(--rail-accent-rgb, 0, 244, 255), 0.6);
    color: var(--rail-accent);
}
.vibe-rail-toggle .icon-collapsed { display: none; }
.vibe-rail.collapsed .vibe-rail-toggle .icon-expanded { display: none; }
.vibe-rail.collapsed .vibe-rail-toggle .icon-collapsed { display: inline; }

/* Collapsed state -------------------------------------------------------- */
.vibe-rail.collapsed { width: var(--uni-rail-collapsed-width); }
.vibe-rail.collapsed .vibe-rail-inner { display: none; }
body.uni-rail-collapsed.uni-rail-fixed { padding-left: var(--uni-rail-collapsed-width); }
body.uni-rail-collapsed .vibe-layout { grid-template-columns: var(--uni-rail-collapsed-width) 1fr; gap: 1.25rem; }

/* Inner contents --------------------------------------------------------- */
.vibe-rail-inner {
    padding-top: 0.5rem;
    padding-right: 0.5rem;
    padding-bottom: 0.5rem;
}
.vibe-rail--fixed .vibe-rail-inner { padding-right: 0.25rem; }

.vibe-rail-heading {
    font-family: 'Share Tech Mono', monospace;
    font-size: 0.7rem;
    color: rgba(var(--rail-accent-rgb, 0, 244, 255), 0.7);
    letter-spacing: 0.12em;
    text-transform: uppercase;
    margin: 0 1.75rem 1rem 0;
    padding-bottom: 0.5rem;
    border-bottom: 1px solid rgba(var(--rail-accent-rgb, 0, 244, 255), 0.15);
}

.vibe-rail-section { margin-bottom: 1.25rem; }
.vibe-rail-part {
    display: block;
    font-family: 'Rajdhani', sans-serif;
    font-size: 0.85rem;
    font-weight: 600;
    color: rgba(255, 255, 255, 0.85);
    text-decoration: none;
    text-transform: uppercase;
    letter-spacing: 0.04em;
    padding: 0.35rem 0 0.35rem 0.6rem;
    border-left: 2px solid transparent;
    transition: color 0.15s, border-color 0.15s;
}
.vibe-rail-part:hover { color: var(--rail-accent); }
.vibe-rail-part.active { color: var(--rail-accent); border-left-color: var(--rail-accent); }

.vibe-rail-section ul {
    list-style: none;
    padding: 0;
    margin: 0.2rem 0 0;
}
.vibe-rail-section ul a {
    display: flex;
    align-items: baseline;
    gap: 0.5rem;
    font-family: 'Rajdhani', sans-serif;
    font-size: 0.78rem;
    color: rgba(224, 224, 224, 0.65);
    text-decoration: none;
    padding: 0.25rem 0 0.25rem 0.6rem;
    border-left: 2px solid transparent;
    line-height: 1.3;
    transition: all 0.15s;
}
.vibe-rail-section ul a:hover {
    color: var(--rail-accent);
    background: rgba(var(--rail-accent-rgb, 0, 244, 255), 0.04);
    border-left-color: rgba(var(--rail-accent-rgb, 0, 244, 255), 0.4);
}
.vibe-rail-section ul a.active,
.vibe-rail-section ul a.current {
    color: var(--rail-accent);
    background: rgba(var(--rail-accent-rgb, 0, 244, 255), 0.07);
    border-left-color: var(--rail-accent);
}

.vibe-rail-num {
    font-family: 'Share Tech Mono', monospace;
    font-size: 0.7rem;
    color: rgba(var(--rail-accent-rgb, 0, 244, 255), 0.65);
    flex-shrink: 0;
    min-width: 1.8em;
}
.vibe-rail-section ul a.active .vibe-rail-num,
.vibe-rail-section ul a.current .vibe-rail-num { color: var(--rail-accent); }

.vibe-rail-status {
    font-family: 'Share Tech Mono', monospace;
    font-size: 0.6rem;
    margin-left: auto;
    padding: 0.05rem 0.35rem;
    border-radius: 2px;
    letter-spacing: 0.06em;
    text-transform: uppercase;
}
.vibe-rail-status--live { background: rgba(0,255,136,0.15); border: 1px solid rgba(0,255,136,0.4); color: #00ff88; }
.vibe-rail-status--sub  { background: rgba(0,244,255,0.10); border: 1px solid rgba(0,244,255,0.3);  color: #00f4ff; }

.vibe-rail-coming {
    font-family: 'Share Tech Mono', monospace;
    font-size: 0.75rem;
    color: rgba(255, 230, 0, 0.7);
    padding: 0.25rem 0 0.25rem 0.6rem;
    border-left: 2px solid rgba(255, 230, 0, 0.25);
    display: flex;
    align-items: baseline;
    gap: 0.5rem;
}
.vibe-rail-coming .vibe-rail-num { color: rgba(255, 230, 0, 0.85); }

/* Mobile — hide rail, reset body shift -------------------------------------- */
@media (max-width: 1024px) {
    .vibe-layout { grid-template-columns: 1fr; gap: 0; }
    .vibe-rail { display: none; }
    body.uni-rail-fixed { padding-left: 0; }
    body.uni-rail-collapsed.uni-rail-fixed { padding-left: 0; }
}