i.file {
    width: 18px;
    height: 18px;
    background: url(../img/file.svg) no-repeat;
    background-size: cover;
}
i.github {
    display: inline-block;
    margin-left: .2rem;
    width: 2rem;
    height: 2rem;
    position: relative;
    top: .5rem;
    background: url(../img/github.svg) no-repeat;
    background-size: cover;
}
i.open {
    display: inline-block;
    position: relative;
    top: 2px;
    width: 16px;
    height: 16px;
    margin-right: 4px;
    background: url(../img/open.svg) no-repeat;
    background-size: cover;
}
i.save {
    display: inline-block;
    position: relative;
    top: 2px;
    width: 16px;
    height: 16px;
    margin-right: 4px;
    background-image: url(../img/save.svg);
}
.btn.dir::before {
    content: ' ';
    display: inline-block;
    width: 20px;
    height: 20px;
    background: url(../img/dir.svg) no-repeat;
    background-size: cover;
    transition: background .15s;
}
.btn.dir:hover::before {

    background: url(../img/dir-active.svg) no-repeat;
    background-size: cover;
}
.btn.del::before {
    content: ' ';
    width: 20px;
    height: 20px;
    display: inline-block;
    background: url(../img/delete.svg) no-repeat;
    background-size: cover;
}
footer {
    text-align: center;
}
.file-tree input[type=checkbox] {
    width: 16px;
    height: 16px;
}
.guide li {
    padding: 4px 0 4px 0;
    margin-left: 2rem;
}