html,* { font-family: 'Inter'; box-sizing: border-box; }
body { background-color: #fafafa; line-height:1.6;}
.lead { font-size: 1.5rem; font-weight: 300; }
.container { margin: 150px auto; max-width: 960px; }
ul.tree, ul.tree * {
    list-style-type: none;
    margin: 0;
    padding: 0 0 5px 0;
}
ul.tree img.arrow {
    padding: 2px 0 0 0;
    border: 0;
    width: 20px;
}
ul.tree li {
    padding: 4px 0 0 0;
    line-height: 18px;
}
ul.tree li ul {
    padding: 0 0 0 20px;
    margin: 0;
}
ul.tree label {
    cursor: pointer;
    font-weight: bold;
    padding: 2px 0;
}
ul.tree label.hover {
    color: red;
}

ul {
    margin-top: 5px;
    margin-bottom: 5px;
}
ul.tree li .arrow {
    width: 20px;
    height: 18px;
    padding: 0;
    margin: 0;
    cursor: pointer;
    float: left;
    background: transparent no-repeat 0 0px;
}
ul.tree li .collapsed {
    background-image: url(images/right.svg);
}
ul.tree li .expanded {
    background-image: url(images/down.svg);
}

ul.tree li .checkbox {
    width: 20px;
    height: 18px;
    padding: 0;
    margin: 0;
    cursor: pointer;
    float: left;
    background: url(images/square.svg) no-repeat 0 0px;
}
ul.tree li .checked {
    background-image: url(images/check.svg);
}
ul.tree li .half_checked {
    background-image: url(images/square-minus.svg);
}