.course-shell{padding-top:calc(var(--nav-h) + 40px);padding-bottom:80px}.course-shell__wrap{max-width:var(--max);margin:0 auto;padding:0 24px;display:grid;grid-template-columns:1fr;grid-gap:40px;gap:40px}.course-shell__rail{border:1px solid var(--border);border-radius:12px;background:var(--surface)}.course-shell__rail-toggle{display:flex;align-items:center;justify-content:space-between;gap:12px;padding:14px 18px;cursor:pointer;list-style:none;font-family:var(--mono);font-size:11px;letter-spacing:.12em;text-transform:uppercase;color:var(--accent-dim)}.course-shell__rail-toggle::-webkit-details-marker{display:none}.course-shell__rail-toggle:focus-visible{outline:2px solid var(--accent);outline-offset:2px;border-radius:8px}.course-shell__rail-chevron{flex-shrink:0;color:var(--accent);transition:transform .22s ease}.course-shell__rail[open] .course-shell__rail-chevron{transform:rotate(180deg)}.course-shell__rail-body{padding:4px 18px 18px}@media (min-width:960px){.course-shell__wrap{grid-template-columns:280px minmax(0,1fr);gap:56px}.course-shell__rail{position:-webkit-sticky;position:sticky;top:calc(var(--nav-h) + 24px);align-self:start;max-height:calc(100vh - var(--nav-h) - 48px);overflow-y:auto;border:0;border-radius:0;background:transparent}.course-shell__rail-toggle{display:none}.course-shell__rail-body{display:block;padding:0}}.course-shell__main{min-width:0}.course-sidebar{font-family:var(--sans)}.course-sidebar__home{display:block;font-family:var(--mono);font-size:11px;letter-spacing:.1em;text-transform:uppercase;color:var(--accent);text-decoration:none;line-height:1.4;margin-bottom:24px;padding-bottom:16px;border-bottom:1px solid var(--border)}.course-sidebar__home:hover{color:var(--accent-dim)}.course-sidebar__modules{list-style:none;margin:0;padding:0;counter-reset:none}.course-sidebar__module{margin-bottom:20px}.course-sidebar__module-link{display:flex;gap:10px;align-items:baseline;text-decoration:none;color:var(--text-primary);margin-bottom:8px}.course-sidebar__module-num{font-family:var(--mono);font-size:10px;color:var(--text-muted);letter-spacing:.05em}.course-sidebar__module-title{font-size:13.5px;font-weight:600;line-height:1.35}.course-sidebar__module--active .course-sidebar__module-title,.course-sidebar__module-link:hover .course-sidebar__module-title{color:var(--accent-dim)}.course-sidebar__lessons{list-style:none;margin:0 0 0 4px;padding:0 0 0 16px;border-left:1px solid var(--border)}.course-sidebar__lesson{margin:0 0 2px}.course-sidebar__lesson-link{display:block;padding:5px 8px;font-size:13px;line-height:1.4;color:var(--text-secondary);text-decoration:none;border-radius:6px;transition:color .15s,background .15s}.course-sidebar__lesson-link:hover{color:var(--text-primary);background:var(--surface)}.course-sidebar__lesson--active .course-sidebar__lesson-link{color:var(--accent-dim);font-weight:600;background:rgba(184,148,63,.08)}.course-sidebar__lesson--planned{display:flex;align-items:center;justify-content:space-between;gap:8px;padding:5px 8px}.course-sidebar__lesson--planned .course-sidebar__lesson-title{font-size:13px;line-height:1.4;color:var(--text-muted)}.course-sidebar__soon{flex-shrink:0;font-family:var(--mono);font-size:8.5px;letter-spacing:.1em;text-transform:uppercase;color:var(--text-muted);border:1px solid var(--border);border-radius:999px;padding:1px 7px}.course-nav{font-family:var(--sans)}.course-nav__crumbs{list-style:none;display:flex;flex-wrap:wrap;align-items:center;margin:0 0 20px;padding:0;font-family:var(--mono);font-size:11px;letter-spacing:.04em}.course-nav__crumb{display:inline-flex;align-items:center;color:var(--text-muted)}.course-nav__crumb a{color:var(--text-secondary);text-decoration:none}.course-nav__crumb a:hover{color:var(--accent-dim)}.course-nav__sep{margin:0 8px;color:var(--text-muted)}.course-nav__crumb [aria-current=page]{color:var(--text-primary)}.course-nav__adjacent{display:grid;grid-template-columns:1fr 1fr;grid-gap:16px;gap:16px;margin-top:48px;padding-top:32px;border-top:1px solid var(--border)}.course-nav__adj{display:flex;flex-direction:column;gap:6px;padding:16px 18px;border:1px solid var(--border);border-radius:10px;text-decoration:none;background:var(--card);transition:border-color .2s,box-shadow .2s}.course-nav__adj:hover{border-color:var(--accent);box-shadow:0 8px 24px -16px rgba(26,24,22,.25)}.course-nav__adj--next{text-align:right}.course-nav__adj-dir{font-family:var(--mono);font-size:10px;letter-spacing:.08em;text-transform:uppercase;color:var(--accent-dim)}.course-nav__adj-title{font-size:14px;font-weight:600;line-height:1.35;color:var(--text-primary)}@media (max-width:600px){.course-nav__adjacent{grid-template-columns:1fr}.course-nav__adj--next{text-align:left}}