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640px){.grid-cols-2{grid-template-columns:repeat(2,1fr)}}@media (min-width: 1024px){.grid-cols-3{grid-template-columns:repeat(3,1fr)}}@media (min-width: 1280px){.grid-cols-4{grid-template-columns:repeat(4,1fr)}}.featured-grid{grid-template-columns:1fr}@media (min-width: 768px){.featured-grid{grid-template-columns:repeat(2,1fr)}}@media (min-width: 1024px){.featured-grid{grid-template-columns:repeat(3,1fr)}}.concept-card{background:#fff;border-radius:.75rem;box-shadow:0 4px 6px #0000001a;border:1px solid var(--slate-200);padding:1.5rem;cursor:pointer;transition:all .3s;group:card}.concept-card:hover{box-shadow:0 20px 25px 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.5rem;border-radius:9999px}.difficulty-tag{font-size:.75rem;padding:.25rem .5rem;border-radius:9999px}.difficulty-beginner{background:var(--green-100);color:var(--green-800)}.difficulty-intermediate{background:var(--yellow-100);color:var(--yellow-800)}.difficulty-advanced{background:var(--red-100);color:var(--red-800)}.card-footer{display:flex;align-items:center;justify-content:space-between;font-size:.75rem;color:var(--slate-500)}.date-info{display:flex;align-items:center;gap:.25rem}.arrow-icon{width:.75rem;height:.75rem;transition:transform .3s}.concept-card:hover .arrow-icon{transform:translate(2px)}.no-results{text-align:center;padding:4rem 1rem}.no-results-icon{width:6rem;height:6rem;background:var(--slate-100);border-radius:50%;display:flex;align-items:center;justify-content:center;margin:0 auto 1rem}.no-results h4{font-size:1.25rem;font-weight:600;color:var(--slate-900);margin-bottom:.5rem}.no-results 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