.series-group { border:1px solid var(--border); border-radius:16px; background:rgba(12,22,37,.58); overflow:hidden; }
.series-group > summary { cursor:pointer; list-style:none; padding:14px 16px; display:flex; align-items:center; justify-content:space-between; gap:12px; }
.series-group > summary::-webkit-details-marker { display:none; }
.series-group > summary::after { content:"＋"; color:var(--muted); font-size:18px; }
.series-group[open] > summary::after { content:"−"; }
.series-group-content { display:grid; gap:10px; padding:0 12px 12px; }
.series-season { margin:5px 4px 0; color:var(--muted); font-size:12px; text-transform:uppercase; letter-spacing:.08em; }
.series-group .list-item { margin:0; }