.btn{
    font-weight: 600;
    color: #fff;
    background: -moz-linear-gradient(top, #BF3737, #671111);
    background: -webkit-linear-gradient(top, #BF3737, #671111);
    background: linear-gradient(to bottom, #BF3737, #671111);
}

.menu-btn {
    position: fixed;
    top: 0px;
    right: 0px;
    display: flex;
    height: 71px;
    width: 71px;
    justify-content: center;
    align-items: center;
    z-index: 90;
    background-color: #dcc0bf;
}
.menu-btn span,
.menu-btn span:before,
.menu-btn span:after {
    content: '';
    display: block;
    height: 3px;
    width: 25px;
    border-radius: 3px;
    /*ボタンの線の色*/
    background-color: #535353;
    position: absolute;
    transition: all 300ms 0s ease;
}
.menu-btn span:before {
    bottom: 8px;
}
.menu-btn span:after {
    top: 8px;
}

#menu-btn-check {
    display: none;
}
#menu-btn-check:checked ~ .menu-btn span {
    background-color: rgba(255, 255, 255, 0);/*メニューオープン時は真ん中の線を透明にする*/
    transition: all 300ms 0s ease;
}
#menu-btn-check:checked ~ .menu-btn span::before {
    bottom: 0;
    transform: rotate(45deg);
    background-color: #535353;
    transition: all 300ms 0s ease;
}
#menu-btn-check:checked ~ .menu-btn span::after {
    top: 0;
    transform: rotate(-45deg);
    background-color: #535353;
    transition: all 300ms 0s ease;
}

.menu-content {
    width: 100%;
    height: 100%;
    position: fixed;
    top: 0;
    left: 100%;
    z-index: 80;
    background-color: white;
    color: #222;
    transition: all 500ms 0s ease;
}

#menu-btn-check:checked ~ .menu-content {
    left: 0;/*メニューを画面内へ*/
}

.menu-content ul {
    padding: 70px 10px 0;
}
.menu-content ul li {
    border-bottom: solid 1px #ccc;
    list-style: none;
}
.menu-content ul li a {
    display: block;
    width: 100%;
    font-size: 16px;
    box-sizing: border-box;
    text-decoration: none;
    padding: 15px 15px 15px 0;
    position: relative;
}
.menu-content ul li a::before {
    content: "";
    width: 7px;
    height: 7px;
    border-top: solid 2px #000;
    border-right: solid 2px #000;
    transform: rotate(45deg);
    position: absolute;
    right: 11px;
    top: 24px;
}

.z-index-1 {
	z-index: -1;
}