* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

body {
    font-family: Arial, sans-serif;
    background-color: #f0f0f0;
}

header {
    background-color: #4CAF50;
    color: white;
    padding: 10px 0;
}

nav {
    display: flex;
    justify-content: space-between;
    align-items: center;
    max-width: 1200px;
    margin: auto;
    padding: 0 20px;
}

nav .logo {
    font-size: 24px;
    font-weight: bold;
}

nav ul {
    list-style: none;
    display: flex;
}

nav ul li {
    margin-left: 20px;
}

nav ul li a {
    color: white;
    text-decoration: none;
}

main {
    max-width: 1200px;
    margin: 20px auto;
    padding: 20px;
    background-color: white;
    border-radius: 8px;
    box-shadow: 0 2px 10px rgba(0, 0, 0, 0.1);
}

.activity-list {
    display: flex;
    flex-wrap: wrap;
    gap: 20px;
}

.activity-card {
    background-color: #e7f3fe;
    border: 1px solid #b9e1ff;
    border-radius: 8px;
    padding: 20px;
    width: calc(33% - 20px);
}

.activity-card h3 {
    margin-bottom: 10px;
}

.register-btn {
    background-color: #4CAF50;
    color: white;
    border: none;
    padding: 10px;
    border-radius: 5px;
    cursor: pointer;
}

.register-btn:hover {
    background-color: #45a049;
}

form {
    display: flex;
    flex-direction: column;
}

form label {
    margin-top: 10px;
}

form input, form select {
    padding: 10px;
    margin-top: 5px;
    border: 1px solid #ccc;
    border-radius: 5px;
}

form button {
    margin-top: 15px;
    padding: 10px;
    background-color: #4CAF50;
    color: white;
    border: none;
    border-radius: 5px;
    cursor: pointer;
}

form button:hover {
    background-color: #45a049;
}

footer {
    text-align: center;
    padding: 10px;
    background-color: #4CAF50;
    color: white;
    position: relative;
    bottom: 0;
    width: 100%;
    margin-top: 20px;
}