/*styling for body*/
body {
    font-family: Arial, sans-serif;
    margin: 0;
    padding: 0;
    background-color: #ffffff;
    color: #383838;
}

/*styling for container web page content*/
.container {
    max-width: 800px;
    margin: 20px auto;
    padding: 20px;
    background-color: #ffffff;
    border: 1px solid #d2d2d7;
    border-radius: 0;
}

/*styling for h1 and h2 heading in html dimgray*/
h1, h2 {
    color: #696969;
}

/*main navigation top menu background in html dimgray*/
.main-menu {
    background-color: #696969;
    padding: 12px 0;
}

/*styling for menu list*/
.main-menu ul {
    display: flex;
    justify-content: center;
    list-style: none;
    margin: 0;
    padding: 0;
}

.main-menu li {
    margin: 0 15px;
}

/*styling for menu link*/
.main-menu a {
    color: #ffffff;
    text-decoration: none;
    padding: 10px;
    border-radius: 0;
}

/*menu tab hover effect*/
.main-menu a:hover {
    background-color: #333333;
}

/*current menu tab in-use effect*/
.main-menu a.active {
    background-color: #0071e3;
}

.center-img {
    display: block;
    margin: 20px auto;
    border: 1px solid #d2d2d7;
}

/*table layout*/
table {
    width: 100%;
    border-collapse: collapse;
    margin: 20px 0;
}

/*table cells*/
th, td {
    border: 1px solid #d2d2d7;
    padding: 10px;
    text-align: left;
}

/*table header in html darkgray with html white text*/
th {
    background-color: #a9a9a9;
    color: #ffffff;
}

/*styling for list*/
ul, ol {
    margin: 15px 0;
    padding-left: 30px;
}