.m18-tutorial-main{padding-top:96px}.m18-tutorial-browser{padding-bottom:42px}.m18-simple-head{padding:18px 0 8px}.m18-simple-head h1{font-size:clamp(2.2rem,5vw,4rem);line-height:.95;letter-spacing:-.07em;margin:0 0 .7rem}.m18-simple-head p{max-width:820px;color:var(--m18-muted);font-size:1.05rem}.m18-branch-tiles{display:grid;grid-template-columns:repeat(3,minmax(0,1fr));gap:14px;margin:18px 0}.m18-branch-tile{display:flex;align-items:center;gap:13px;background:white;border:1px solid var(--m18-line);border-radius:22px;padding:14px;color:var(--m18-text);box-shadow:0 10px 26px rgba(28,50,91,.06)}.m18-branch-tile:hover{border-color:#a9c1ff;transform:translateY(-1px)}.m18-branch-tile img{width:70px;height:54px;border-radius:16px;object-fit:cover;background:#f3f7ff}.m18-branch-tile strong{display:block;font-size:1.05rem}.m18-branch-tile small{display:block;color:var(--m18-muted);font-weight:750}.m18-tutorial-layout{display:grid;grid-template-columns:minmax(0,1fr) 320px;gap:24px;align-items:start}.m18-topic-menu{display:grid;gap:12px}.m18-menu-details,.m18-menu-link{background:white;border:1px solid var(--m18-line);box-shadow:0 10px 26px rgba(28,50,91,.045)}.m18-menu-details{border-radius:22px;overflow:hidden}.m18-menu-details summary{list-style:none;display:flex;align-items:center;justify-content:space-between;gap:12px;padding:18px 20px;cursor:pointer;font-weight:900;color:#173259}.m18-menu-details summary::-webkit-details-marker{display:none}.m18-menu-details summary b{font-size:1.4rem;color:var(--m18-brand);transition:transform .16s}.m18-menu-details[open]>summary b{transform:rotate(45deg)}.m18-menu-details--root>summary{font-size:1.35rem;background:linear-gradient(90deg,#1d9dff,#6ec6ff);color:#fff}.m18-menu-details--root>summary b{color:#fffb3a}.m18-menu-details--d1{margin:10px 12px;border-radius:18px}.m18-menu-details--d1>summary{background:#f7f9ff}.m18-menu-details--d2{margin:8px 0;border-radius:14px}.m18-menu-children{padding:10px 12px 14px}.m18-menu-link{display:flex;align-items:center;gap:12px;min-height:54px;border-radius:16px;margin:8px 0;padding:10px 14px;color:#26324a;font-weight:790}.m18-menu-link:hover{color:#10284e;border-color:#a9c1ff;background:#f7faff}.m18-menu-link img{width:42px;height:42px;border-radius:12px;object-fit:cover;background:#eef4ff;flex:0 0 auto}.m18-menu-link span{flex:1}.m18-menu-link b{color:#12d9ee;font-size:1.2rem}.m18-menu-link--d2{margin-left:14px}.m18-menu-link--d3{margin-left:28px}.m18-popular-panel{position:sticky;top:96px;background:white;border:1px solid var(--m18-line);border-radius:24px;padding:18px;box-shadow:0 12px 32px rgba(28,50,91,.07);display:grid;gap:14px}.m18-popular-panel h2{font-size:1.15rem;margin:0}.m18-popular-grid{display:grid;gap:10px}.m18-mini-topic{display:flex;gap:10px;align-items:center;padding:10px;border:1px solid var(--m18-line);border-radius:16px;color:var(--m18-text);background:#fbfdff}.m18-mini-topic:hover{border-color:#a9c1ff}.m18-mini-topic img{width:54px;height:54px;border-radius:14px;object-fit:cover;background:#eef4ff}.m18-mini-topic strong{display:block;line-height:1.15}.m18-mini-topic small{display:block;color:var(--m18-muted);font-weight:700;margin-top:3px}@media(max-width:980px){.m18-tutorial-layout{grid-template-columns:1fr}.m18-popular-panel{position:static}.m18-branch-tiles{grid-template-columns:1fr 1fr}}@media(max-width:650px){.m18-tutorial-main{padding-top:82px}.m18-simple-head h1{font-size:2.35rem}.m18-branch-tiles{grid-template-columns:1fr}.m18-menu-details--root>summary{font-size:1.12rem}.m18-menu-details summary{padding:15px 14px}.m18-menu-children{padding:8px}.m18-menu-link{border-radius:14px}.m18-menu-link--d2,.m18-menu-link--d3{margin-left:0}}

/* v5: miniaturas de tutoriales respetan 16:9 */
.m18-topic-menu .m18-menu-link img{width:96px;height:54px;aspect-ratio:16/9;object-fit:cover;border-radius:10px;background:#f6f9ff;border:1px solid #dce4f2}.m18-mini-topic img{width:96px;height:54px;aspect-ratio:16/9;object-fit:cover;border-radius:12px}.m18-menu-link{grid-template-columns:auto 1fr auto}@media(max-width:640px){.m18-topic-menu .m18-menu-link img,.m18-mini-topic img{width:76px;height:43px}}


/* v6: tutoriales como galería visual en filas/columnas */
.m18-tutorial-layout{grid-template-columns:1fr!important}.m18-popular-panel{display:none!important}.m18-topic-menu{gap:18px}.m18-menu-details--root{border-radius:26px}.m18-menu-details--root>summary{padding:20px 24px}.m18-menu-children{display:grid;grid-template-columns:repeat(auto-fill,minmax(180px,1fr));gap:16px;padding:18px}.m18-menu-details--d1,.m18-menu-details--d2{grid-column:1/-1;margin:0;border-radius:22px;background:#f9fbff}.m18-menu-details--d1>.m18-menu-children,.m18-menu-details--d2>.m18-menu-children{grid-template-columns:repeat(auto-fill,minmax(165px,1fr));padding:16px}.m18-menu-link{display:flex!important;flex-direction:column;align-items:stretch;justify-content:flex-start;gap:10px;min-height:168px;margin:0!important;padding:12px;border-radius:20px;text-align:left;overflow:hidden;background:#fff}.m18-topic-menu .m18-menu-link img{width:100%!important;height:auto!important;aspect-ratio:16/9!important;border-radius:16px;object-fit:cover}.m18-menu-link span{font-size:1rem;line-height:1.2;display:block;min-height:2.4em}.m18-menu-link b{align-self:flex-end;margin-top:auto}.m18-menu-link:not(:has(img))::before{content:'Matemáticas18';display:flex;align-items:center;justify-content:center;width:100%;aspect-ratio:16/9;border-radius:16px;background:linear-gradient(135deg,#eaf4ff,#f7fbff);border:1px dashed #c8d9f4;color:#6b7894;font-size:.88rem;font-weight:850}.m18-menu-details summary{border-radius:inherit}.m18-branch-tile{flex-direction:column;align-items:stretch}.m18-branch-tile img{width:100%;height:auto;aspect-ratio:16/9;border-radius:18px}@media(max-width:650px){.m18-menu-children,.m18-menu-details--d1>.m18-menu-children,.m18-menu-details--d2>.m18-menu-children{grid-template-columns:repeat(2,minmax(0,1fr));gap:12px;padding:12px}.m18-menu-link{min-height:142px;border-radius:16px}.m18-menu-link span{font-size:.92rem}.m18-simple-head h1{font-size:2.05rem}}@media(max-width:420px){.m18-menu-children,.m18-menu-details--d1>.m18-menu-children,.m18-menu-details--d2>.m18-menu-children{grid-template-columns:1fr}}



/* v7: solo las ramas principales se contraen; los subgrupos quedan siempre abiertos */
.m18-menu-details:not(.m18-menu-details--root) > summary{cursor:default;pointer-events:none;background:#f7faff;border-bottom:1px solid #e0e8f7}
.m18-menu-details:not(.m18-menu-details--root) > summary b{display:none}
.m18-menu-details:not(.m18-menu-details--root) > summary .m18-menu-summary__text::after{content:' · temas';font-size:.78rem;color:#70819c;margin-left:.45rem;font-weight:800}
.m18-menu-details:not(.m18-menu-details--root){grid-column:1/-1;border:1px solid #dbe7fb;background:#fff}
.m18-menu-details:not(.m18-menu-details--root) .m18-menu-children{display:grid!important;max-height:none!important;overflow:visible!important}
.m18-branch-tiles{grid-template-columns:repeat(4,minmax(0,1fr))}.m18-branch-tile[href="#estadistica"]{background:linear-gradient(135deg,#fff,#f4fff9)}
.m18-menu-link.is-placeholder{opacity:.86}.m18-menu-link.is-placeholder b{color:#8aa0bd}.m18-menu-link.is-placeholder::after{content:'Nuevo';position:absolute;right:10px;top:10px;font-size:.7rem;font-weight:900;background:#eafff4;color:#078b5a;padding:.28rem .5rem;border-radius:999px}.m18-menu-link{position:relative}
@media(max-width:980px){.m18-branch-tiles{grid-template-columns:repeat(2,minmax(0,1fr))}}@media(max-width:650px){.m18-branch-tiles{grid-template-columns:1fr}}