.challenge-grid {
    display: grid; grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
    gap: 25px; width: 100%; max-width: 1000px; margin: 0 auto;
}
.challenge-card {
    position: relative; /* Added to fix admin buttons inside card */
    background-color: hsla(0, 0%, 100%, 0.05); 
    border-radius: 16px; border: 1px solid hsla(0, 0%, 100%, 0.05); 
    padding: 0; overflow: hidden; cursor: pointer; transition: transform 0.2s, box-shadow 0.2s, background-color 0.2s; width: 100%; 
}
.challenge-card:hover {
    background-color: hsla(0, 0%, 100%, 0.08); transform: translateY(-5px); box-shadow: 0 12px 30px 0 rgba(0,0,0,0.5); 
}
.challenge-card img { width: 100%; height: 160px; object-fit: cover; display: block; border-bottom: 1px solid hsla(0, 0%, 100%, 0.1); }
.challenge-card-content { padding: 20px; }
.challenge-card-content h3 { margin: 0 0 5px 0; font-size: 20px; }
.challenge-card-content p { margin: 0; color: hsla(0, 0%, 100%, 0.6); font-size: 14px; }