.course-index-mobile{display:none}@media(max-width:900px){.lesson-layout>.course-index{display:none}.course-index-mobile{display:block;width:min(calc(100% - 2.5rem),46rem);margin:1.5rem auto 0;border:1px solid var(--line);border-radius:.5rem;background:#fff}.course-index-mobile summary{display:flex;align-items:center;justify-content:space-between;gap:1rem;padding:.8rem 1rem;color:var(--ink);font-size:.875rem;font-weight:800;cursor:pointer}.course-index-mobile summary span{color:var(--muted);font-size:.75rem;font-weight:700}.course-index-mobile[open] summary{border-bottom:1px solid var(--line)}.course-index-mobile ol{display:grid;gap:.15rem;padding:.6rem 0;margin:0;list-style:none}.course-index-mobile a{display:grid;grid-template-columns:1.6rem 1fr;gap:.45rem;align-items:start;padding:.45rem 1rem;color:var(--muted);font-size:.8rem;line-height:1.35;text-decoration:none}.course-index-mobile a:hover{color:var(--blue)}.course-index-mobile a>span{color:#94a3b8;font-size:.72rem;font-weight:800}.course-index-mobile .is-current a{color:var(--blue);font-weight:800}.lesson-layout{width:100%}.lesson-layout .lesson-article{width:min(calc(100% - 2.5rem),46rem);margin:0 auto}}@media(max-width:560px){.course-index-mobile{width:calc(100% - 2rem)}.lesson-layout .lesson-article{width:min(calc(100% - 2rem),46rem)}}