*[shown="false"] {
    visibility: hidden;
    display: none;
    opacity: 0;
    width: 0;
    height: 0;
}

*[shown="true"] {
    opacity: 1;
}

/* ----------------- */

section#screen_panel {
    display: block;
    position: fixed;
    left: 0;
    right: 0;
    top: 0;
    bottom: 0;
}

section#content_pane, section#info_pane {
    position: absolute;
    display: block;
    top: 0;
    bottom: 0;
}

section#content_pane {
    left: 0;
    width: 80vw;
    background-color: lightcyan;
}

section#info_pane {
    right: 0;
    width: 20vw;
    background-color: beige;
}

.info-pane-element {
    display: block;
    left: 0;
    right: 0;
    padding: 1em;
}

section#user_info {
    position: relative;
    top: 0;
    background-color: aquamarine;
    font-size: 18pt;
    text-align: center;
}

section#action_panel {
    background-color: antiquewhite;
}

iframe#content_frame {
    display: block;
    width: 100%;
    height: 100%;
    border: 0 transparent;
}

section#table_section {
    position: sticky;
    height: calc(100vh - 4em);
    overflow-y: auto;
}

table.management {
    width: 100%;
    border-collapse: collapse;
}

table.management thead th {
    padding: 0.5em 0;
    position: sticky;
    top: 0;
    background-color: darkgray;
}

table.management tbody td {
    border: 1pt lightgrey solid;
    padding: 0.3em 0.5em;
}

table.management tbody tr[highlight="true"] {
    background-color: antiquewhite;
}

table.management tbody tr[highlight="false"] td input {
    pointer-events: none;
}

section#user_manager_action_bar {
    margin-top: 0.5em;
}

section.window {
    position: fixed;
    display: block;
    top: 0;
    right: 0;
    bottom: 0;
    left: 0;
    background-color: rgba(128, 128, 128, 0.7);
    padding: 4em;
}

section.window-inner {
    margin: 0 auto;
    display: block;
    border: 2pt solid darkslategray;
    background-color: whitesmoke;
    padding: 1em;
    width: fit-content;
}

td.checkbox {
    width: 0;
}

.hintbox-window {
    position: fixed;
    display: block;
    width: 15em;
    height: 8em;
}

/* ----- */

section#game_list_panel {
    display: block;
    position: absolute;
    left: 0;
    right: 0;
}

section.group-box {
    margin: 1em;
    left: 0;
    right: 0;
    background-color: beige;
}

span.group-box-caption {
    display: block;
    left: 0;
    right: 0;
    padding: 1em;
    background-color: chartreuse;
}

section.group-box-inner {
    display: inline-table;
    padding: 1em;
    collapse: 1em;
    border-spacing: 1em;
}

section.game-box {
    display: table-cell;
    width: 8em;
    height: 8em;
    border: 2pt dashed gray;
    text-align: center;
    vertical-align: middle;
    cursor: pointer;
}

section#test_area {
    display: block;
    position: absolute;
    left: 0;
    right: 0;
}

section.challenge {

}

span.question {

}

section.answer-container {

}

section.answer {

}