body {
    font-family: Arial, sans-serif;
    margin: 0;
    padding: 0;
    background-color: #f4f4f4;
}

header {
    background-color: #333;
    color: #fff;
    padding: 20px;
    text-align: center;
}

h1 {
    margin: 0;
}

h2 {
    color: #333;
}

nav ul {
    list-style-type: none;
    padding: 0;
}

nav ul li {
    display: inline;
    margin: 0 15px;
}

nav ul li a {
    color: #333;
    text-decoration: none;
    font-weight: bold;
}

section {
    padding: 20px;
    margin: 20px;
    background-color: #fff;
    box-shadow: 0 2px 4px rgba(0,0,0,0.1);
}

.images img, .exercise img {
    width: 100%;
    max-width: 300px;
    margin-bottom: 10px;
}

.responsive {
    width: 100%;
    height: auto;
}

.exercise-links {
    display: flex;
    flex-wrap: wrap;
    justify-content: space-around;
}

.exercise {
    margin: 15px;
    text-align: center;
}

ol {
    padding-left: 20px;
}