header {
    margin: -10px 0px 0px -10px;
    padding-left: 5px;
    display: grid;
    grid-template-areas:
        "hamburger title  title"
        "nav    nav    nav";
}

.menu-chkbx{
    display: none;
}

.menu-burger {
    grid-area: hamburger;
    padding: 30px 20px 30px 0;
    position: relative;
    visibility: visible;
}

.hamburger {
    display: block;
    height: 2px;
    width: 20px;
    position: relative;
    background: rgb(0,0,0);
}

.hamburger:before {
    top: 5px;
}
.hamburger:after{
    top:-5px;
}

.hamburger:before, .hamburger:after{
    background: rgb(0,0,0);
    display: block;
    width: 100%;
    height:100%;
    content:'';
    position: absolute;
}

.menu-chkbx:checked ~ .menu-burger .hamburger {
    background: transparent;
}

.menu-chkbx:checked ~ .menu-burger .hamburger:before {
    transform:rotate(-45deg);
}

.menu-chkbx:checked ~ .menu-burger .hamburger:after {
    transform:rotate(45deg);
}

.menu-chkbx:checked ~ .menu-burger .hamburger:before,
.menu-chkbx:checked ~ .menu-burger .hamburger:after {
    top:0;
}

nav ul li {
    margin: 10px 0px 10px 0px;
    text-align: center;
    border: 1px solid rgb(0,0,0);
}

.menu {
    grid-area: nav;
    display: flex;
    flex-direction: column;
    max-height: 0;
    overflow: hidden;
    margin: 0;
    padding: 0;
}

.menu-chkbx:checked ~ .menu {
    max-height: 250px;
    position: absolute;
    margin-top: 62px;
    z-index:1;
    border-radius: 5px;
    background-color: rgb(220,220,220);
}

header h1 {
	display: flex;
	grid-area: title;
	font-size: 20px;
	margin: 10px -10px 0px 0px;
	align-items: center;
	width:100%;
}