:root {
    --menuBtnSize: 200px;
}

body {
    background-color: #333;
}

#app {
    background-color: #333;
}

.menu-btn-area {
    position: fixed;
    top: calc(-0.5 * var(--menuBtnSize));
    left: calc(-0.5 * var(--menuBtnSize));
    width: var(--menuBtnSize);
    height: var(--menuBtnSize);
    border-radius: 50%;
    background-color: #ff7979;
    z-index: 1;
    display: flex;
}

.menu-btn-area .menu-btn {
    width: 100%;
    height: 100%;
    position: absolute;
    transition: 1s ease;
}
.menu-btn-area .menu-btn i:nth-child(1) {
    position: absolute;
    bottom: 20%;
    right: 25%;
}
.menu-btn-area .menu-btn i:nth-child(2) {
    position: absolute;
    bottom: 20%;
    left: 25%;
}
.menu-btn-area .menu-btn i:hover {
    cursor: pointer;
}

.menus {
    position: fixed;
    bottom: 10%;
    left: -50%;
    color: white;
    transition: 1s ease;
}
.menus div {
    margin: 20px 0;
    padding-bottom: 3px;
    transition: 1s ease;
}
.menus div:hover {
    cursor: pointer;
    border-bottom: 1px solid white;
}

.content {
    position: absolute;
    top: 0;
    left: 0;
    background-color: white;
    width: 100vw;
    transition: 1s ease;
    transform-origin: top left;
}
.article {
    margin: 50px auto;
    width: 60%;
    height: 100%;
}

/* animate */
#app.show-menu .menus {
    left: 30px;
}
#app.show-menu .menus div:nth-child(1) {
    transform: translateX(10px);
}
#app.show-menu .menus div:nth-child(2) {
    transform: translateX(30px);
}
#app.show-menu .menus div:nth-child(3) {
    transform: translateX(50px);
}

#app.show-menu .menu-btn {
    transform: rotate(-90deg);
}

#app.show-menu .content {
    transform: rotate(-20deg);
}