body {
    margin: 0;
    font-family: 'Arial', sans-serif;
    background: linear-gradient(to right, #15aef6, #09cfa4);
    color: #fff;
}
header {
    text-align: center;
    padding: 20px;
    background-color: rgba(0, 0, 0, 0.8);
}
header h1 {
    font-size: 3rem;
    margin: 0;
}
header p {
    font-size: 1.2rem;
}
.container {
    padding: 20px;
    max-width: 1200px;
    margin: auto;
}
.challenge-card {
    background: rgba(0, 0, 0, 0.6);
    border-radius: 10px;
    padding: 20px;
    margin-bottom: 20px;
    box-shadow: 0 4px 10px rgba(0, 0, 0, 0.3);
    transition: transform 0.3s, box-shadow 0.3s;
}
.challenge-card:hover {
    transform: translateY(-10px);
    box-shadow: 0 8px 20px rgba(0, 0, 0, 0.4);
}
.best-section {
    text-align: center;
    margin-top: 20px;
}
footer {
    text-align: center;
    padding: 20px;
    bottom: 0;
    width: 100%;
}
footer p {
    margin: 0;
    font-size: 0.9rem;
}