:root {
    --animate-duration: 1s;
    --animate-delay: 1s;
    --animate-repeat: 1;

    --dark-blue: #334a5e;
    --dark-green: #4d5d5f;
    --cobber: #ab7e69;
    --light-blue: #728daa;
}

main {
    position: relative;
    animation: fade-in 1s cubic-bezier(.39,.575,.565,1) .5s both;
    z-index: 1;

    width: 100vw;
    height: 100vh;
}

@keyframes fade-in {
    0% {
        opacity: 0
    }
    to {
        opacity: 1
    }
}

@keyframes color-change_background {
    0% {
        background-color: var(--dark-blue);
    }
    33.333333333333333% {
        background-color: var(--dark-green);
    }

    66.666666666666667% {
        background-color: var(--light-blue);
    }
    95% {
        background-color: var(--cobber);
    }
    100% {
        background-color: var(--dark-blue);
    }
}

@keyframes color-change_fill {
    0% {
        fill: var(--light-blue);
    }
    33.333333333333333% {
        fill: var(--cobber);
    }

    66.666666666666667% {
        fill: var(--dark-blue);
    }
    95% {
        fill: var(--dark-green);
    }
    100% {
        fill: var(--light-blue);
    }
}

@keyframes color-change_button {
    0% {
        background-color: var(--light-blue);
        color: var(--dark-blue);
    }
    33.333333333333333% {
        background-color: var(--cobber);
        color: var(--dark-green);
    }

    66.666666666666667% {
        background-color: var(--dark-blue);
        color: var(--light-blue);
    }
    95% {
        background-color: var(--dark-green);
        color: var(--cobber);
    }
    100% {
        background-color: var(--light-blue);
        color: var(--dark-blue);
    }
}

@keyframes color-change_menu {
    0% {
        color: var(--light-blue);
        background-color: var(--dark-blue);
    }
    33.333333333333333% {
        color: var(--cobber);
        background-color: var(--dark-green);
    }

    66.666666666666667% {
        color: var(--dark-blue);
        background-color: var(--light-blue);
    }
    95% {
        color: var(--dark-green);
        background-color: var(--cobber);
    }
    100% {
        color: var(--light-blue);
        background-color: var(--dark-blue);
    }
}

.main--background {
    position: absolute;

    top: 0;
    right: 0;
    bottom: 0;
    left: 0;

    background-image: url(../img/background_arrif.jpg);
    background-size: cover;
    background-repeat: no-repeat;
    background-position: center center;
    background-color: var(--dark-blue);
    background-blend-mode: soft-light;

    animation: color-change_background 20s cubic-bezier(.39,.575,.565,1) 2s infinite;
    pointer-events: none;
}

.main--background_overlay {
    position: absolute;

    top: 0;
    right: 0;
    bottom: 0;
    left: 0;

    background-color: var(--dark-blue);

    opacity: 0.87;

    animation: color-change_background 20s cubic-bezier(.39,.575,.565,1) 2s infinite;
    pointer-events: none;
}

.main--logo {
    position: relative;
    display: inline-block;
}

.main--logo svg {
    width: calc(10rem + 10vw);
    height: auto;
    fill: var(--light-blue);

    animation: color-change_fill 20s cubic-bezier(.39,.575,.565,1) 2s infinite;
}

@media screen and (max-width: 575px) {
    .main--logo svg {
        width: calc(10rem + 20vw);
    }
}

.main--button {
    position: relative;
    display: inline-block;

    background-color: var(--light-blue);
    color: var(--dark-blue);

    font-size: calc(1rem + 0.5vw);
    line-height: 1.5;

    padding: 0.5em 1em;
    border-radius: 0.25em;    
    margin-top: 5em;
    border: 0;
    
    animation: color-change_button 20s cubic-bezier(.39,.575,.565,1) 2s infinite;
}

.menu {
    position: fixed;
    left: 0;
    top: 0;
    width: 100%;
    height: 100%;
    overflow: hidden;
    pointer-events: none;
    z-index: 150;
}

.menu--visible {
    pointer-events: auto;
}

.app-menu {
    background-color: var(--dark-blue);
    color: var(--light-blue);
    position: relative;
    width: 100%;
    height: 100%;
    box-shadow: 0 2px 6px rgba(0, 0, 0, 0.5);
    -webkit-transform: translateY(103%);
            transform: translateY(103%);
    
    display: flex;
    flex-direction: column;
    justify-content: center;
    align-items: start;

    text-align: center;
    
    will-change: transform;
    z-index: 160;
    pointer-events: auto;

    /* animation: color-change_menu 20s cubic-bezier(.39,.575,.565,1) 2s infinite; */
}

@media screen and (max-width: 767px) {
    .app-menu {
        overflow: auto;
        justify-content: start;
        padding: 3vh 0;
    }
}

.menu--visible .app-menu {
    -webkit-transform: none;
            transform: none;
}

.menu--animatable .app-menu {
    transition: all 130ms ease-in;
}

.menu--visible.menu--animatable  .app-menu {
    transition: all 330ms ease-out;
}

.menu:after {
    content: '';
    display: block;
    position: absolute;
    left: 0;
    top: 0;
    width: 100%;
    height: 100%;
    background: rgba(0,0,0,0.4);
    opacity: 0;
    will-change: opacity;
    pointer-events: none;
    transition: opacity 0.3s cubic-bezier(0,0,0.3,1);
}

.menu--visible.menu:after {
    opacity: 1;
    pointer-events: auto;
}

.menu a {
    color: inherit;
    text-decoration: underline;
    opacity: 0.67;
}
.menu a:hover {
    opacity: 1;
}

hr {
    margin: calc(1rem + 3vh) 0;
}