.hamburger-btn {
    display: none;
}

.outer-menu {
    display: none;
}

@media screen and (max-width: 780px) {
        
    .hamburger-btn,
    .hamburger-btn span {
        display: inline-block;
        transition: all .4s;
        box-sizing: border-box;
        cursor: pointer;
    }
    .hamburger-btn {
        display: block;
        position: relative;
        background: none;
        border: none;
        appearance: none;
        height: 5.87vw;
        width: 6.67vw;
        z-index: 10;
        border: 1px solid transparent;
        position: fixed;
        top: 6.67vw;
        right: 6.67vw;
    }
    .hamburger-btn span {
        position: absolute;
        left: 0;
        width: 100%;
        background-color: #BD1E2F;
        border-radius: 0.5vw;
        height: 1vw;
    }

    .hamburger-btn span:nth-of-type(1) {
        top: 0.1vw;
    }
    .hamburger-btn span:nth-of-type(2) {
        top: 2.2vw;
    }
    .hamburger-btn span:nth-of-type(3) {
        bottom: 0.1vw;
    }
    .hamburger-btn.active {
        transform: rotate(360deg);
    }
    .hamburger-btn.active span:nth-of-type(1) {
        transform: translateY(2.1vw) rotate(-45deg);
    }
    .hamburger-btn.active span:nth-of-type(2) {
        transform: translateY(0) rotate(45deg);
    }
    .hamburger-btn.active span:nth-of-type(3) {
        opacity: 0;
    }
    .outer-menu {
        display: block;
        position: fixed;
        top: 0;
        left: 0;
        width: 100%;
        height: 100%;
        pointer-events: none;
        visibility: hidden;
        overflow: hidden;
        backface-visibility: hidden;
        outline: 1px solid transparent;
        display: flex;
        align-items: center;
        justify-content: center;
        z-index: 9;
    }
    .outer-menu.active {
        visibility: visible;
        pointer-events: auto;
    }
    .outer-menu > div {
        width: 250vw;
        height: 250vw;
        color: #FEFEFE;
        background: #2D2C2C;
        border-radius: 50%;
        transition: all 0.4s ease;
        flex: none;
        transform: scale(0);
        backface-visibility: hidden;
        overflow: hidden;
        display: flex;
        align-items: center;
        justify-content: center;
    }

    .outer-menu.active > div {
        transform: scale(1);
        transition-duration: 0.75s;
    }
    .outer-menu > div > div {
        text-align: center;
        max-width: 90vw;
        max-height: 100vh;
        opacity: 0;
        transition: opacity 0.4s ease;
        overflow-y: auto;
        flex: none;
        display: flex;
        align-items: center;
        justify-content: center;
    }
    .outer-menu.active > div > div {
        opacity: 1;
        transition: opacity 0.4s ease 0.4s;
    }
    .outer-menu > div > div > ul {
        list-style: none;
        padding: 0 1em;
        margin: 0;
        display: block;
        max-height: 100vh;
    }
    .outer-menu > div > div > ul > li {
        padding: 0;
        margin: 1em;
        font-size: 24px;
        display: block;
    }

    .outer-menu > div > div > ul > li > a {
        position: relative;
        display: inline;
        cursor: pointer;
        transition: color 0.4s ease;
        text-decoration: none;
        color: #e5e5e5;
    }
    .outer-menu > div > div > ul > li > a:hover {
        color: #e5e5e5;
    }
    .outer-menu > div > div > ul > li > a:hover:after {
        width: 100%;
    }
    .outer-menu > div > div > ul > li > a:after {
        content: '';
        position: absolute;
        z-index: 1;
        bottom: -0.15em;
        left: 0;
        width: 0;
        height: 2px;
        background: #e5e5e5;
        transition: width 0.4s ease;
    }
}