body
{
        background-image:linear-gradient(to top, hsla(202, 83%, 58%, 0.9) 0%, hsla(195, 92%, 60%, 0.7) 50%);
        height: 100%;
        margin: 0;
        padding: 0;
        font-family:sans-serif;

}


footer
{
    text-align: center;
    font-size: 80%;
    line-height: 160%;
    position: absolut;
    width: 100%;
    padding-top: 20vh;
    margin: 0;
}

nav
{
        /* text-align: center; */
        display: flex;
        align-items: center;
        justify-content: center;
        padding: 0;
        margin: 0;
        box-shadow: 0 0 3px 3px Gainsboro;
        background-image: linear-gradient(to top, hsla(220, 90%, 37%, 1.0) 0%, hsla(207, 90%, 37%, 0.4) 90%);
}

p, div,  h1,  h2, h3, h4, h5, td, th, ul, li, ol, footer, main
{
    font-family:tahoma, arial, helvetica, sans-serif;
    color: #00008B;
}

p, div, td, th, ul, li, ol, main
{
        font-size: 1em
}


div
{
        line-height: 160%;
}

h1
{
        background-image:
        url("../03medien/bilder/logo-potsdamersv-blau.png"),
        url("../03medien/bilder/schwimmbecken-lang.jpg");
        background-size: 25%, cover;
        background-repeat: no-repeat;
        background-position: center;
        padding-top: 9%;
        padding-bottom: 9%;
        text-align: center;
        font-size: 180%;
        font-weight: bold;
        margin: 0;
        text-shadow:
        2px  2px 2px white,
        2px -2px 2px white,
        -2px  2px 2px white,
        -2px -2px 2px white;
}

h2
{
        font-size: 150%;
}

h3
{
    font-size: 140%;
    font-weight: bold;
    text-align: center;
    text-shadow:
        1px  1px 1px #F0FFFF,
        1px -1px 1px #F0FFFF,
        -1px  1px 1px #F0FFFF,
        -1px -1px 1px #F0FFFF;
}

h4, h5
{
        font-size:120%;
}

nav ul
{
        margin: 0;
        padding: 0;
        display: flex;
        flex-direction: column;
}

nav li {
        list-style: none;
        margin: 0.3em;
        padding: 0;
        font-size: 1.2em;
        white-space:nowrap

}

@media (min-width: 60em)
{
    nav ul
        {
        flex-direction: row;
    }
    nav li
        {
        flex: 1;
        font-size: 1em;
    }
}

nav a
{
        display: block;
        padding: 0.4em;
        text-decoration: none;
        font-weight: bolder;
        text-align: center;
        color:hsla(45, 100%, 50%, 1.0);
}

nav li[aria-current] a
{
        background-color: firebrick;
        color: gold;
}

nav a:focus,
nav a:hover,
nav li[aria-current] a:focus,
nav li[aria-current] a:hover
{
        color: darkblue;
        background-color: gold;
}

<!-- .navi
{
        padding-right: 1.2vw;
        padding-left: 1.2vw;
        font-size: 110%;
        color:hsla(45, 100%, 50%, 1.0);
        font-weight: normal;
        line-height:2.0em;
}
 -->
.button-noaktiv
{
    text-align: center;
    font-weight: bold;
    font-size: 14pt;
    color: grey;
    text-decoration:none;
    <!-- text-shadow: 2px 2px 2px white, 2px -2px 2px white, -2px 2px 2px white, -2px -2px 2px white; -->
    background-color: #58ACFA;
    line-height:3em;
    padding:10px;
    border-radius: 4px;
    box-shadow: 0 0 3px 3px Gainsboro;
    width:300px;
    background-image: linear-gradient(to top, hsla(47, 96%, 86%, 1.0) 0%, hsla(47, 96%, 86%, 0.8) 90%);
    margin: 10px;
}
a.button
{
    text-align: center;
    font-weight: bold;
    font-size: 14pt;
    color: #FFFFFF;
    text-decoration:none;
    <!-- text-shadow: 2px 2px 2px white, 2px -2px 2px white, -2px 2px 2px white, -2px -2px 2px white; -->
    background-color: #58ACFA;
    line-height:3em;
    padding:10px;
    border-radius: 4px;
    box-shadow: 0 0 3px 3px Gainsboro;
    width:300px;
    background-image: linear-gradient(to top, hsla(195, 87%, 56%, 1.0) 0%, hsla(195, 87%, 56%, 0.2) 100%);
    margin: 10px;
}

a:hover.button
{
    background-image: linear-gradient(to top, hsla(195, 87%, 56%, 0.6) 0%, hsla(195, 87%, 56%, 1.0) 90%);
        text-decoration: none;
        color: #00008B;
}
a:active.button
{
    background-image: linear-gradient(to top, hsla(195, 87%, 56%, 0.6) 0%, hsla(195, 87%, 56%, 1.0) 90%);
    box-shadow: 0 0 3px 3px Gainsboro inset;
        color: #00008B;
}

a, a:active
{
        text-decoration: none;
        color: azure;
}
a:hover, a:focus
{
        text-decoration: none;
        color: white;
}


#content-center
{
        display: flex;
        align-items: center;
        justify-content: center;
}


th
{
    background-color: #483D8B;
    color: #F0F8FF;
}

ul
{
       list-style: square;
}


#small
{
        margin-top: 7px;
        font-family:tahoma, arial, helvetica, sans-serif;
        font-size: 75%;
}

#cr
{
        font-family:tahoma, arial, helvetica, sans-serif;
        font-size:8pt;
        text-align : center;
}

td.head
{
        font-family:tahoma, arial, helvetica, sans-serif;
        font-size: 18pt;
        font-weight : bold;
        color: #F0F8FF;
        background-color: #483D8B;
        text-align: center;
}

#td1
{background-color : #52CCEF}

#td2
{background-color : #C0EDFA}