/* ===== Página de ejercicios ===== */
.ejp-head{padding:calc(var(--nav-h) + 28px) 0 18px}
.ejp-head .title{margin:10px 0 10px}
.ejp-lead{max-width:62ch;color:var(--muted);font-size:17px;line-height:1.6}
.ejp-aviso{display:inline-flex;gap:8px;align-items:flex-start;margin-top:16px;padding:12px 14px;
  border:1px solid var(--line);border-radius:12px;background:color-mix(in srgb,var(--bg) 70%,transparent);
  font-size:14px;color:var(--muted);max-width:58ch}
.ejp-aviso b{color:var(--ink)}

.ejp-filtros{position:sticky;top:var(--nav-h);z-index:50;padding:12px 0;
  background:color-mix(in srgb,var(--bg) 92%,transparent);backdrop-filter:blur(10px);
  -webkit-backdrop-filter:blur(10px);border-bottom:1px solid var(--line)}
.ejp-filtros__fila{display:flex;gap:8px;overflow-x:auto;scrollbar-width:none;padding:2px 0}
.ejp-filtros__fila::-webkit-scrollbar{display:none}
.ejp-filtros__fila + .ejp-filtros__fila{margin-top:8px}
.chip{flex:0 0 auto;min-height:44px;display:inline-flex;align-items:center;gap:6px;
  padding:0 16px;border-radius:999px;border:1.5px solid var(--line);background:transparent;
  color:var(--ink);font-family:inherit;font-weight:700;font-size:14px;cursor:pointer;
  white-space:nowrap;transition:background .15s,border-color .15s,color .15s}
.chip[aria-pressed="true"]{background:var(--yellow);border-color:var(--yellow);color:#15161A}
.chip__n{font-size:12px;opacity:.65;font-weight:600}
.ejp-filtros__lab{flex:0 0 auto;display:inline-flex;align-items:center;padding-right:4px;
  font-family:var(--font-mono);font-size:12px;letter-spacing:.1em;text-transform:uppercase;color:var(--muted)}

.ejp-grid{display:grid;grid-template-columns:1fr;gap:16px;padding:22px 0 10px}
@media (min-width:640px){.ejp-grid{grid-template-columns:repeat(2,1fr);gap:20px}}
@media (min-width:1000px){.ejp-grid{grid-template-columns:repeat(3,1fr);gap:24px}}

.ejc{border:1px solid var(--line);border-radius:16px;overflow:hidden;background:color-mix(in srgb,var(--bg) 60%,transparent);display:flex;flex-direction:column}
.ejc[hidden]{display:none}
.ejc__media{position:relative;aspect-ratio:4/5;background:#16171B;overflow:hidden}
.ejc__media img,.ejc__media video{width:100%;height:100%;object-fit:cover;display:block}
.ejc__ph{position:absolute;inset:0;display:grid;place-items:center;gap:10px;text-align:center;
  background:repeating-linear-gradient(135deg,#17181C 0 12px,#1B1C21 12px 24px);color:#5C5E66}
.ejc__ph span{font-family:var(--font-mono);font-size:12px;letter-spacing:.12em;text-transform:uppercase}
.ejc__badges{position:absolute;left:12px;top:12px;display:flex;gap:6px;flex-wrap:wrap}
.pill{font-family:var(--font-mono);font-size:12px;letter-spacing:.06em;text-transform:uppercase;
  padding:6px 10px;border-radius:999px;background:rgba(10,10,12,.72);color:#F2F2F0;backdrop-filter:blur(6px)}
.pill--facil{background:#2E7D32;color:#fff}
.pill--medio{background:#B08F00;color:#15161A}
.pill--pro{background:#C0392B;color:#fff}
.pill--banda{background:rgba(10,10,12,.72);color:#F9CB00;border:1px solid rgba(249,203,0,.5)}
.ejc__body{padding:16px 16px 18px;display:flex;flex-direction:column;gap:8px;flex:1}
.ejc__n{font-family:var(--font-mono);font-size:12px;color:var(--muted);letter-spacing:.1em}
.ejc__t{font-size:20px;line-height:1.2;margin:0}
.ejc__d{font-size:15px;line-height:1.55;color:var(--muted);margin:0}
.ejc__trabaja{margin-top:auto;padding-top:10px;border-top:1px solid var(--line);
  font-size:13px;color:var(--muted);display:flex;gap:6px;flex-wrap:wrap}
.ejc__trabaja b{color:var(--ink);font-weight:700}

.ejp-vacio{padding:40px 0;text-align:center;color:var(--muted);font-size:16px}
.ejp-cierre{margin:28px 0 60px;padding:24px;border:1px solid var(--line);border-radius:16px;
  display:flex;flex-direction:column;gap:14px;align-items:flex-start}
.ejp-cierre h2{font-size:26px;margin:0}
.ejp-cierre p{margin:0;color:var(--muted);font-size:16px;line-height:1.55}