html { background-image: url('../background.jpg'); background-repeat: repeat; }
body { margin: auto; width: 950px; font-family: arial,helvetica,sans-serif; font-size: 12px; line-height: 1.3em; }
img { float: right; border: 2px solid; color: rgb(174, 177, 182); margin-left: 10px; }
a:link {
    color: cadetblue;
}
a:visited {
    color: lightseagreen;
}
a:hover {
    color: palevioletred;
}
a:hover img { border: 2px solid yellowgreen; }
.topnav {
    background-color: steelblue;
    overflow: hidden;
}
.topnav a {
    float: left;
    display: block;
    color: #f2f2f2;
    text-align: center;
    padding: 14px 16px;
    text-decoration: none;
    font-size: 17px;
}
.topnav a:hover {
    background-color: #ddd;
    color: black;
}
.active {
    background-color: #4CAF50;
    color: white;
}
.topnav .icon {
    display: none;
}
#header { width: 644px; height: 48px; display: block; margin: auto; background-image: url('../banner.png'); background-repeat: no-repeat; }
h1 { color: yellowgreen; font-size: 50px; text-align: center; margin-top: 20px; margin-bottom: 20px; padding-top: 20px; letter-spacing: 0.02em; font-family: arial,helvetica,sans-serif; }
h2 { color: lightgreen; font-size: 16px; text-align: justify; margin-top: 5px; margin-bottom: 5px; padding-top: 5px; font-family: arial,helvetica,sans-serif; }
h4 { color: rgb(174, 177, 182); cursor: pointer; margin-left: 30px; text-decoration: underline; }
.section { background-color: rgb(255, 255, 255); padding: 10px 20px; margin-right: 10px; margin-left: 10px; border: 3px solid rgb(174, 177, 182); }
.section p { color: rgb(0, 0, 0); }
#content { margin: auto; width: 950px; }
p { color: rgb(255, 255, 255); font-size: 1.2em; line-height: 1.5em; }
footer { clear: both; font-size: 0.75em; text-align: center; }
footer a { color: yellowgreen; }
.descriptions { background-color: rgb(0, 0, 0); padding: 10px; border: 2px solid rgb(174, 177, 182); margin: 15px; }
h4:hover { color: yellowgreen; }
iframe { height: 500px; width: 320px; }
.tab {
    overflow: hidden;
    border: 1px solid yellowgreen;
    background-color: black;
}
.tab button {
    background-color: inherit;
    color: white;
    float: left;
    border: none;
    outline: none;
    cursor: pointer;
    padding: 14px 16px;
    transition: 0.3s;
}
.tab button:hover {
    background-color: seagreen;
}
.tab button.active {
    background-color: darkgreen;
}
.tabcontent {
    display: none;
    animation: fadeEffect 0.5s;
    padding: 6px 12px;
    border: 1px solid yellowgreen;
    border-top: none;
}
@keyframes fadeEffect {
    from {opacity: 0;}
    to {opacity: 1;}
}
ol {
  font-size: 1.2em; line-height: 1.5em; 
  color: rgb(255, 255, 255);
}