* {
  -webkit-box-sizing: border-box;
  -moz-box-sizing: border-box;
  box-sizing: border-box;
}
*:before,
*:after {
  -webkit-box-sizing: border-box;
  -moz-box-sizing: border-box;
  box-sizing: border-box;
}

body, html {
    padding: 0 20px;
    margin: 0;
    font-family: Arial, Tahoma;
}

@media (max-width: 900px) {
    body, html {
        padding: 0 5px;
    }
}

.important {
    background-color: #f9c6c6;
    color: #980000;
    padding: 15px 20px;
    border-radius: 7px;
    margin: 20px 0;
    margin-left: -20px;
}

.tasks,
header,
main {
    max-width: 1000px;
    margin-left: auto;
    margin-right: auto;
    margin-top: 30px;
}

h1 {
    font-size: 70px;
    font-weight: 800;
    line-height: 80px;
}

.date {
    color: #34a84f;
    font-size: 16px;
    margin-top: 30px;
    text-align: right;
}

section {
    margin-top: 40px;
}

.task__name {
    font-size: 18px;
    font-weight: bold;
}

.task__description {
    font-size: 16px;
    line-height: 22px;
}

blockquote {
    border-left: 3px solid #ddd;
    padding-left: 10px;
    padding-top: 0px;
    padding-bottom: 0px;
    margin-left: 20px;
}

.solved {
    color: #ccc;
}

.hint, .hint * {
    color: transparent;
}

.row {
    display: flex;    
}

.row .column-6 {
    width: 50%;
    display: inline-block;
}

@media (max-width: 900px) {
    .row .column-6 {
        width: 100%;
    }
}

.bg-darkgray {
    background: #333;
}

/* Tables */
table {
    border-spacing: 0;
    margin-bottom: 13px;
}

table th,
table td {
    border-right: 1px solid rgba(0, 0, 0, 0.3);
    border-bottom: 1px solid rgba(0, 0, 0, 0.3);
    padding: 2px 12px;
    margin: 0;
}

@media (max-width: 900px) {
    table th,
    table td {  
        padding: 2px 8px;
    }
}

table th {
    border-bottom: 1px solid rgba(0, 0, 0, 0.8);
}

table th:last-child,
table td:last-child {
    border-right: 1px solid rgba(0, 0, 0, 0.8);
}

table tr:last-child td {
    border-bottom: 1px solid rgba(0, 0, 0, 0.8);
}

table {
    border-left: 1px solid rgba(0, 0, 0, 0.8);
    border-top: 1px solid rgba(0, 0, 0, 0.8);
}


/* Logic table */
table.logic-table .question {
    background-color: rgba(255, 100, 100, 0.2);
}


/* Adjacency matrix */
table.adjacency-matrix tr:first-child td,
table.adjacency-matrix tr td:first-child {
    background-color: #eee;
}

table.adjacency-matrix tr:first-child td:first-child {
    background-color: #ccc;
}


/* Excel */
table.excel tr:first-child td,
table.excel tr td:first-child {
    background-color: #eee;
}

table.excel tr:first-child td:first-child {
    background-color: #ccc;
}

/* Code */
code {
    background: #fdfdfd;
    border: 1px solid #ddd;
    border-left: 1px solid #f9a987;
    color: #666;
    page-break-inside: avoid;
    font-family: monospace;
    font-size: 15px;
    line-height: 1.6;
    margin-bottom: 1.6em;
    margin-top: 1em;
    max-width: 100%;
    overflow: auto;
    padding: 1em 1.5em;
    display: block;
    word-wrap: break-word;
    white-space: pre-wrap;
}