body {
    font-family: sans-serif;
    margin: 20px;
}

table {
    border-collapse: collapse;
    margin: auto;
    table-layout: fixed;
}

th, td {
    border: 1px solid #ccc;
    text-align: center;
    cursor: pointer;

    width: 50px;
    height: 28px;

    font-size: 18px;
    padding: 0;
    line-height: 24px;
}

th {
    background-color: #eee;
}

td.empty {
    background-color: #ff4c4c;
} /* red for empty cells */

td.blue-highlight {
    background-color: #4c8cff !important; 
} /* category highlight */

#popup { 
    display: none;
    position: fixed;
    top: 50%; 
    left: 50%;
    transform: translate(-50%, -50%);
    background: white;
    border: 2px solid #333;
    padding: 10px 20px 20px 20px;
    z-index: 1000;

    max-width: 100vw;      /* expand to fit content */
    width: max-content;    /* never exceed screen width */
    max-height: 80vh;      /* prevents popup from exceeding screen height */
    overflow: hidden;

    scrollbar-gutter: stable;
}

/* Sticky header containing title and close button */

#popupHeader {
    position: sticky;
    top: 0;
    background: white;
    display: flex;
    align-items: center;
    justify-content: space-between;
    margin-bottom: 6px;
}

/* Close button */

#popupClose {
    border: none;
    background: none;
    font-size: 26px;
    font-weight: bold;
    cursor: pointer;
    line-height: 1;
}

#popupClose:hover {
    color: red;
}

#popupTitle {
    margin: 0;
}

/* Popup layout */

#popupToggle {
    display: block;
    margin-bottom: 8px;
}

#popupContent {
    margin: 0;
    padding-left: 20px;
    max-height: calc(80vh - 90px);
    overflow: auto;
    scrollbar-width: none; /* Firefox */
}

/* Scrollbars appear only when scrolling (Chromium/Safari) */

#popupContent::-webkit-scrollbar {
    width: 6px;
    height: 6px;
}

#popupContent::-webkit-scrollbar-thumb {
    background: transparent;
}

#popupContent:hover::-webkit-scrollbar-thumb {
    background: rgba(0,0,0,0.35);
    border-radius: 4px;
}


/* Prevent word wrapping */

#popup li {
    white-space: nowrap;
}

#overlay {
    display: none;
    position: fixed;
    top:0;
    left:0;
    width:100%;
    height:100%;
    background: rgba(0,0,0,0.5);
    z-index: 999;
}

#controls {
    margin-bottom: 20px;
}

.incomplete-header { background-color: #ff4c4c; }

#categories {
    display: flex;
    flex-wrap: wrap;
    gap: 6px;
    justify-content: center;
}

#categoryFilters {
    display: flex;
    flex-wrap: wrap;
    gap: 8px;
}

#categoryFilters label {
    white-space: nowrap;
}

/* Top-right buttons */
#infoButtons {
    position: absolute;
    top: 20px;
    right: 20px;
}

#infoButtons button {
    margin-left: 10px;
    cursor: pointer;
}

/* Info popup */
#infoOverlay {
    display: none;
    position: fixed;
    top:0;
    left:0;
    width:100%;
    height:100%;
    background: rgba(0,0,0,0.5);
    z-index: 1100;
}

#infoPopup {
    display: none;
    position: fixed;
    top: 50%;
    left: 50%;
    transform: translate(-50%, -50%);
    background: white;
    border: 2px solid #333;
    padding: 15px 20px;
    z-index: 1200;

    max-width: 600px;
    max-height: 80vh;
    overflow: auto;
}

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

#infoHeader button {
    border: none;
    background: none;
    font-size: 22px;
    cursor: pointer;
}