html {
    height: 100%;
}
body {
    margin: 0;
    min-height: 100%;
    display: flex;
    flex-direction: column;
    align-items: center;
    font-family: Arial, sans-serif;
}
.hidden {
    display: none !important;
}

.centered-container {
    flex-grow: 1;
    min-height: 100%;
    width: 70%;
    min-width: 1000px;
    display: flex;
    flex-direction: column;
    box-shadow: 0px 0px 10px rgba(0, 0, 0, 0.5);
}
header {
    display: flex;
    background: #def;
}
header .pic-box {
    flex-shrink: 0;
    background-position: top left;
    background-repeat: no-repeat;
    background-size: 100% 100%;
}
header .heading {
    flex-grow: 1;
    display: flex;
    flex-direction: column;
    font-size: 16pt;
    padding: 1em 1em;
    max-width: 1200px;
}
header .heading .conference-topic {
    color: #46e;
    margin: 0.5em 0;
    font-size: 26pt;
    font-family:  Arial, sans-serif;
    text-align: center;
}

.conference-info {
    display: flex;
}
.flex-separator {
    flex-grow: 1;
}


.sub-header {
    height: 1em;
    font-size: 12pt;
    font-weight: bold;
    color: #fff;
    background: #5ac;
    text-align: right;
}

.main-container {
    display: flex;
    flex-grow: 1;
}

nav.sidebar-container {
    display: block;
    background: #def;
    font-size: 12pt;
    padding: 1em;
    box-sizing: border-box;
    flex-shrink: 0;
}
header .pic-box, nav.sidebar-container {
    width: 256px;
}
ul.vertical-nav {
    display: flex;
    flex-direction: column;
    list-style: none;
    margin: 0;
    padding: 0;
}
ul.vertical-nav li {
    padding: 0 0;
}
.vertical-nav a, .vertical-nav a:visited {
    display: block;
    color: #25c;
    padding: 0.3em 1em;
    border-left: 0.2em solid #588;
    text-decoration: none;
    white-space: nowrap;
    font-weight: bold;
}
.vertical-nav a:hover {
    color: #333;
    text-decoration: underline;
    background: rgba(0, 0, 0, 0.05);
    border-color: #5af;
}

footer {
    background: #469;
    padding: 0.5em;
}
.footer-text {
    color: #fff;
    text-align: center;
}

.sponsors {
    display: flex;
    justify-content: center;
}
.sponsors img {
    height: 130px;
    margin: 0.5em 1em;
}
.bltp-logo {
    filter: drop-shadow(0 0 4px white);
}

.content-container {
    flex-grow: 1;
    display: flex;
    flex-direction: column;
    width: 100%;
}
.content-header {
    font-size: 18pt;
    padding: 0.5em 1em;
    background: #e6ffff;
    border-bottom: 0.1em solid #588;
    color: #167;
}
.content-wrapper {
    flex-grow: 1;
    background: #d8f6f6;
    padding: 0 2em 1em;
    font-size: 12pt;
}
.content-wrapper h1 {
    font-size: 18pt;
    color: #006ddb;
}
.content-wrapper h2 {
    font-size: 16pt;
    color: #0063c6;
}
.content-wrapper p {
    margin: 1em 0 0;
    color: #000;
    font-size: 1em;
}
.content-wrapper table td {
    padding: 0.2em 4ch 0.2em 0;
}
.content-wrapper ul.simple-list {
    padding: 0 0 0 1.5em;
    margin: 0;
    list-style: square;
}
.content-wrapper > *:first-child {
    margin-top: 1em;
}
.content-wrapper a, .content-wrapper a:visited {
    color: #0063c6;
    text-decoration: none;
}
.content-wrapper a:hover {
    color: #800;
    text-decoration: underline;
}
.content-wrapper .subblock {
    display: block;
    margin-left: 2em;
}

.text-justify {
    text-align: justify;
}

/*--- Registration ---*/
form#reg_form {
    display: flex;
    flex-direction: column;
    align-items: center;
}
.form-row-group {
    border-top: 1px solid #888;
    padding: 2em 2em;
}
.form-row-group:first-of-type {
    border: none;
}
.form-row-group *:first-child {
    margin-top: 0;
}
form#reg_form input, form#reg_form select, form#reg_form textarea, form#reg_form button {
    font-size: 13pt;
    font-family: Arial, sans-serif;
    width: 50ch;
    padding: 0.3em;
    display: block;
    box-sizing: border-box;
    margin-top: 1em;
    border: 1px solid #666;
}
textarea {
    resize: none;
    height: 8em;
}
option {
    color: black;
    font-style: normal;
}
input::placeholder, option.placeholder, select:invalid, textarea::placeholder {
    color: #777;
    font-style: italic;
}
input:invalid, select:invalid {
    outline: rgba(220, 20, 20, 0.8) solid 1px;
    outline-offset: 2px;
}
.radio-group {
    display: flex;
    flex-direction: row;
    margin-top: 0.5em;
}
input[type=radio] {
    display: none;
}
.radio-group label {
    text-align: center;
    display: block;
    padding: 0.3em;
    width: 50%;
    height: 100%;
    margin: 0;
    border: 1px solid #888;
    box-sizing: border-box;
    background: white;
    cursor: pointer;
}
.radio-group label:hover {
    background: #ddf;
}
input[type=radio]:checked + label {
    background: #8af;
    color: white;
}
form#reg_form button {
    cursor: pointer;
    background: #bbf;
}
form#reg_form button:hover {
    background: #8e8;
}
form#reg_form button:active {
    background: #ffa;
}

.notification {
    margin-top: 1em;
    text-align: center;
}
.notification .on-success {
    color: #2d2;
}
.notification .on-error {
    color: #d22;
}

/*--- Image Gallery ---*/
.image-thumbs {
    display: flex;
    flex-direction: row;
    flex-wrap: wrap;
    justify-content: center;
    align-items: center;
}
.image-thumbs img {
    margin: 10px 5px;
    width: 150px;
    box-shadow: 3px 3px 5px -1px black;
    transition: 200ms;
    cursor: pointer;
}
.image-thumbs img:hover {
    transform: scale(1.2, 1.2);
}

.fixed-overlay {
    z-index: 10;
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    padding: 2em;
    background: rgba(0, 0, 0, 0.8);
    text-align: center;
}
.fixed-overlay button {
    cursor: pointer;
}
.fixed-overlay button:focus {
    outline: none;
}
.current-image-container {
    height: 100%;
    display: inline-block;
    background: rgba(0, 0, 0, 0.3);
    font-size: 0;
}
.current-image-container * {
    display: inline-block;
    vertical-align: middle;
    font-size: 18pt;
}
.current-image-container img {
    max-height: 100%;
    max-width: 100%;
    padding: 0 2em;
    box-sizing: border-box;
}
.current-image-container button {
    background: rgba(0, 0, 0, 1);
    border: none;
    padding: 0;
    transition: 200ms;
    opacity: 0.5;
    height: 100%;
    color: #fff;
    width: 2em;
}
button#previous_image {
    margin-right: -2em;
    position: relative;
}
button#next_image {
    margin-left: -2em;
}
.current-image-container button:hover {
    opacity: 1.0;
}
.current-image-container button:active {
    color: #4af;
}
button#close {
    position: absolute;
    top: 0;
    right: 0em;
    font-size: 22pt;
    font-family: Arial, sans-serif;
    color: #999;
    background: none;
    border: none;
    transition: 200ms;
    padding: 0 0.5em;
}
button#close:hover {
    color: #fff;
}

button#load_thumbs {
    display: block;
    margin: 0 auto;
    background: #55aacc;
    font-size: 14pt;
    padding: 0.5em 1em;
    cursor: pointer;
    border: 1px solid #446699;
}
button#load_thumbs:hover {
    background: #ddeeff;
}
button#load_thumbs:focus {
    outline: none;
}
.thumbs-separator {
    height: 0.2em;
    width: 100%;
    background: #446699;
    margin: 10px 0;
}

@media only screen and (max-width: 1080px) {
    body {
        min-width: 1080px;
    }
    .centered-container {
        width: 100%;
    }
}