:root {
    --main-bg-color:  #3AAFA9;
    --other-bg-color: #2B7A78;
    --main-bg-color-rgba: rgba(253, 253, 253, .8);
    --nav-bg-color-rgba: rgba(173, 230, 201, 0.8);
    --main-text-color: #111111;
    --background-odd: rgba(233, 233, 233, .8);
    --background-even: rgba(253, 253, 233, .8);
}

* {
    font-family: verdana;
    line-height: 1.3em;
    margin: 0;
    padding: 0;
}

main,
article,
section,
h1, h2, h3, h4, h5, h6,
nav {
    padding: 1%;
}

html {
    color: var(--main-text-color);
}

header {
    background-color: var(--other-bg-color);
    border: 3px solid black;
    border-bottom: none;
    border-collapse: collapse;
}

body {
    max-width: 50em;
    margin: auto;
    background-color: var(--other-bg-color);
    /* <!-- https://www.w3schools.com/html/html_images_background.asp#:~:text=To%20avoid%20the%20background%20image,repeat%20property%20to%20no%2Drepeat%20. --> */
    background-image: url(../images/background.jpg);
    background-repeat: no-repeat;
    background-attachment: fixed;
    background-size: cover;
}

.index li:nth-child(odd){
    background-color:var(--background-odd);
}

.index li:nth-child(even){
    background-color:var(--background-even);
}

ol {
    border: solid black;
    border-collapse: collapse;
    margin: auto;
    list-style-position: inside;
}

li {
    border: thin solid black;
    padding: .5em;
}

li:nth-child(odd) {
    background-color: var(--background-odd);
}

li:nth-child(even) {
    background-color: var(--background-even);
}

li:hover {
    background-color: lightblue;
}

main, footer {
    background-color: var(--main-bg-color);
}

nav {
    background-color: var(--nav-bg-color-rgba);
    border-bottom: medium solid var(--other-bg-color);
    text-align: center;
}

figure {
    text-align: center;
    padding-bottom: 1%;
}

h1 {
    text-transform: uppercase;
}

img {
    max-width: 100%;
}

p {
    text-indent: 3em;
    padding-bottom: 1em;
}

a:hover {
    color: var(--main-text-color);
}

nav a:link,
nav a:visited {
    color: darkblue;
    text-decoration: none;
}

nav a:hover {
    background-color: var(--main-text-color);
    color: var(--main-bg-color);
    text-decoration: underline;
}

nav a {
    display: inline-block;
    padding: 1%;
}

table {
    border: solid black;
    border-collapse: collapse;
    margin: auto;
}

table+p {
    padding-top: 1em;
}

td,
th {
    border: thin solid black;
    padding: .5em;
}

tr:nth-child(odd) {
    background-color: var(--background-odd);
}

tr:nth-child(even) {
    background-color: var(--background-even);
}

tr:hover {
    background-color: lightblue;
}

caption {
    font-variant: small-caps;
    font-weight: bold;
    padding-top: 1em;
}

cite {
    font-size: xx-small;
}

figcaption {
    font-size: small;
}

form {
    background-color: var(--main-bg-color-rgba);
    border: thin solid black;
    clear: both;
    max-width: 30em;
    margin: auto;
    padding: 1%;
}

form p {
    text-indent: 0;
}

fieldset {
    padding: 1%;
}

label[for^="txt"] {
    display: block;
}

input, textarea {
    width: 99%;
}

input[type="radio"], input[type="checkbox"] {
    width: inherit;
}

legend {
    margin-top: 1%;
}

.form form {
    margin: auto;
    margin-top: 1%;
}

.activePage {
    background-color: var(--main-bg-color-rgba);
}

.buttons {
    text-align: center;
}

.buttons input {
    background-color: lightgreen;
    font-weight: bold;
    font-size: larger;
    padding: .4em;
    width: 50%;
}

.roundedCorners {
    border-radius: 1em;
    border: thin solid #17252A;
}

.mistake {
    color: red;
    background-color: azure;
    padding: .5em;
    text-indent: 0;
}

.founders {
    display: grid;
    grid-template-columns: 1fr 1fr;
    grid-gap: 1em;
    width: 60%;
    margin: auto;
}

.founders figure {
    margin: 0;
}

.contact {
    display: grid;
    grid-template-areas: "box1 box1" "box2 box3" "box4 box4";
    grid-column-gap: 1em;
}

.contact p:nth-child(4) {
    grid-column: span 2;
}

.array td:nth-child(odd) {
    width: 80%
}

.array td:nth-child(even) {
    text-align: center;
}

.array footer {
    padding-top: 4em;
}

.array figure {
    width: 40%;
    margin: auto;
}

.about footer {
    padding-top: 3em;
}