/* Student course pages (My Courses, ISP notes). Tokens and rules: docs/DESIGN.md. */
:root{--bg:#f8fafc;--surface:#ffffff;--border:#e2e8f0;--hover:#f1f5f9;--text:#0f172a;--text-muted:#475569;--accent:#0969da;--accent-press:#0856b3;--dur:120ms}
.sn-layout{display:grid;grid-template-columns:220px minmax(0,1fr);gap:48px;align-items:start;max-width:1200px;margin:0 auto;padding:32px 24px 80px}
.sn-main .course-detail-container,.sn-main .isp-portal-container{max-width:none;margin:0;padding:0}
.sn-nav{position:sticky;top:72px;font-size:14px}
.sn-home,.sn-link,.sn-group>summary{display:flex;align-items:center;justify-content:space-between;gap:8px;min-height:40px;padding:0 12px;border-radius:6px;color:var(--text);text-decoration:none;transition:background-color var(--dur) ease-out}
.sn-home{font-weight:600}
.sn-group{margin-top:16px}
.sn-group>summary{list-style:none;cursor:pointer;font-weight:600}
.sn-group>summary::-webkit-details-marker{display:none}
.sn-group>summary::after{content:"";width:6px;height:6px;border-right:1.5px solid var(--text-muted);border-bottom:1.5px solid var(--text-muted);transform:rotate(-45deg);transition:transform var(--dur) ease-out}
.sn-group[open]>summary::after{transform:rotate(45deg)}
.sn-paper{margin:12px 12px 4px;font-size:13px;color:var(--text-muted)}
.sn-link{color:var(--text-muted)}
.sn-count{font-size:13px;font-variant-numeric:tabular-nums;color:var(--text-muted)}
.sn-sr{position:absolute;width:1px;height:1px;overflow:hidden;clip:rect(0 0 0 0);white-space:nowrap}
.sn-home:hover,.sn-link:hover,.sn-group>summary:hover{background:var(--hover)}
.sn-home:active,.sn-link:active,.sn-group>summary:active{background:var(--border)}
.sn-home[aria-current=page],.sn-link[aria-current=page]{background:var(--hover);color:var(--accent);font-weight:600}
.sn-link[aria-current=page] .sn-count{color:var(--accent)}
.sn-home:focus-visible,.sn-link:focus-visible,.sn-group>summary:focus-visible{outline:2px solid var(--accent);outline-offset:2px}
.sn-main .sn-course{max-width:none;margin:0;padding:8px 0 32px;scroll-margin-top:72px}
.sn-main .sn-course~.sn-course{padding-top:32px;border-top:1px solid var(--border)}
@media (max-width:860px){.sn-layout{grid-template-columns:1fr;gap:24px;padding:16px 16px 64px}.sn-nav{position:static;padding-bottom:16px;border-bottom:1px solid var(--border)}.sn-hub .sn-nav{display:none}}
@media (prefers-reduced-motion:reduce){.sn-home,.sn-link,.sn-group>summary,.sn-group>summary::after{transition:none}}