:root {
    --primary-color: #4CAF50;
    --secondary-color: #f44336;
    --font-family: 'Arial, sans-serif';
}

body {
    font-family: var(--font-family);
    margin: 0;
    padding: 0;
    background-color: #f0f0f0;
}

.main-header {
    background-color: var(--primary-color);
    color: white;
    padding: 20px;
    text-align: center;
}

.main-header h1 {
    margin: 0;
    font-size: 2.5em;
}

.main-nav ul {
    list-style-type: none;
    margin: 0;
    padding: 0;
    display: flex;
    justify-content: center;
    overflow: hidden;
}

.main-nav li {
    padding: 14px 20px;
    margin: 0 15px;
}

.main-nav a {
    text-decoration: none;
    color: white;
    font-weight: bold;
}

.main-nav a:hover {
    background-color: var(--secondary-color);
    border-radius: 4px;
    padding: 14px 20px;
}

.main-content {
    padding: 20px;
}

.main-content h2 {
    color: var(--primary-color);
}

.main-content p {
    line-height: 1.6;
    color: #333;
}

#section1,
#section2,
#section3 {
    background-color: white;
    padding: 20px;
    margin-bottom: 20px;
    border-radius: 8px;
    box-shadow: 0 2px 4px rgba(0, 0, 0, 0.1);
}

#section1 h2,
#section2 h2,
#section3 h2 {
    font-size: 2em;
    margin-top: 0;
    text-align: center;
}

.row {
    display: flex;
    /* justify-content: space-around; */
    /* flex-wrap: wrap; */
    gap: 20px;
}

.card {
    background-color: #fafafa;
    border: 1px solid #ddd;
    border-radius: 8px;
    padding: 15px;
    margin: 10px 0;
    box-shadow: 0 2px 4px rgba(0, 0, 0, 0.1);
    /* width: 360px; */
}

.card:hover {
    transform: translateY(-5px);
    box-shadow: 0 4px 8px rgba(0, 0, 0, 0.2);
    transition: all 0.3s ease;
}

.card h3 {
    font-size: 1.2em;
    margin-top: 0;
    color: var(--primary-color);
}

.card p {
    color: #555;
}

.btn {
    display: inline-block;
    padding: 10px 15px;
    background-color: var(--primary-color);
    color: white;
    text-decoration: none;
    border-radius: 4px;
    margin-top: 10px;
}

.btn:hover {
    background-color: var(--secondary-color);
}

.challenge-table {
    /* width: 100%; */
    border-collapse: collapse;
    margin: 0 auto;
}

.table-header {
    background-color: var(--primary-color);
    color: white;
}

.table-header th {
    padding: 10px 15px;
    border: 1px solid #ddd;
}

.table-row td {
    padding: 10px 15px;
    border: 1px solid #ddd;
    text-align: center;
}

footer {
    background-color: #333;
    color: white;
    text-align: center;
    padding: 10px 0;
    width: 100%;
    bottom: 0;
}

.profile-link {
    color: #ff9800;
    text-decoration: none;
}

.profile-link:hover {
    text-decoration: underline;
    text-underline-offset: 5px;
}

/* media queries */
@media (max-width: 600px) {
    .main-header h1 {
        font-size: 1.8em;
    }

    .main-nav ul {
        flex-direction: column;
    }

    .main-nav li {
        margin: 5px 0;
    }

    .row {
        flex-direction: column;
    }
}