html,
body {

    padding: 0;
    margin: 0;
    height: 100%;
    overflow: hidden;
}

header {
    overflow: hidden;
    background-color: rgba(21, 21, 21, 0.2);
    height: auto;
    align-items: center;
}

nav {
    margin: 0 15rem 0 15rem;
    align-items: center;
    display: flex;
    flex-direction: row;
    justify-content: space-between;
    flex-wrap: nowrap;

}

#logo {
    width: 4rem;
    height: 4rem;
    margin: 0;
}

ul {
    display: flex;
    flex-direction: row;
    flex-wrap: nowrap;
    justify-content: space-between;
}
li {
    padding: 0 0 0 2rem;
    display: inline;
    list-style: none;
}
a {
    align-items: center;
    text-decoration: none;
    font-size: 1.1rem;
    font-family: 'Roboto', sans-serif;
    color: rgb(6, 31, 252);
    position: relative;
    text-transform: uppercase;
    transition: ease-in-out 0.15s;
}

a::after {
    content: "";
    position: absolute;
    bottom: 0;
    left: 0;
    width: 0;
    height: 1px;
    background-color: black;
    transition: 0.15s ease-in-out;
}

:hover:after {
    width: 100%;
}

#admission {
    border: 1px solid rgb(172, 236, 70);
    padding: 8px;
    border-radius: 5px;
    background-color: transparent;
    color: black;
}

#admission:hover {
    background-color: rgb(60, 60, 60);
    color: white;
}

aside {
    display: none;
}

#logo-id::after {
    display: none;
}

#admission::after {
    display: none;
}

/* ipad */
@media(max-width: 64rem) {
    header {
        overflow: hidden;
        height: auto;
        
    }

    nav {
        margin: 0 8rem 0 8rem;
        align-items: center;
        display: flex;
        flex-direction: row;
        justify-content: space-between;
        flex-wrap: nowrap;

    }

    #logo {
        width: 2rem;
        height: 2rem;
        margin: 0;
    }

    li {
        padding: 0 0 0 0.8rem;
        display: inline;
        list-style: none;
    }

    ul {
        display: flex;
        flex-direction: row;
        flex-wrap: nowrap;
        justify-content: space-between;
    }

    a {
        align-items: center;
        text-decoration: none;
        font-size: 0.8rem;
        font-family: 'Roboto', sans-serif;
        color: rgb(60, 60, 60);
        position: relative;
        text-transform: uppercase;
        transition: ease-in-out 0.15s;
    }

    a::after {
        content: "";
        position: absolute;
        bottom: 0;
        left: 0;
        width: 0;
        height: 1px;
        background-color: black;
        transition: 0.15s ease-in-out;
    }

    :hover:after {
        width: 100%;
    }

    #admission {
        border: 1px solid rgb(60, 60, 60);
        padding: 5px;
        border-radius: 5px;
        background-color: transparent;
        color: black;
    }

    #admission:hover {
        background-color: rgb(60, 60, 60);
        color: white;
    }

    aside {
        display: none;
    }

    #logo-id::after {
        display: none;
    }

    #admission::after {
        display: none;
    }

}

/* mobile phone */
@media(max-width: 30rem) {
    ul {
        display: none;
    }
    header {
        background-color: rgba(21, 21, 21, 0.2);
        display: flex;
        flex-direction: row;
        justify-content: space-between;
        align-items: center;

    }
    nav{
        margin: 0 1rem 0 1rem;
    }
    #logo {
        width: 2rem;
        height: 2rem;
    }
    
    .menu-btn {
        margin: 10px 5px 0 0;
        width: 2rem;
        height: 2rem;
        display: flex;
        flex-direction: column;
    }
    
    .menu-btn span {
        margin: 2px;
        width: 50%;
        height: 2.5px;
        background-color: black;
    }

    #sidebtn {

        position: fixed;
        width: 70%;
        top: 0;
        right: 0;
        bottom: 0;
        background-color: rgba(255, 255, 255, 0.5);
        backdrop-filter: blur(5px);
        border-radius: 5px;
    }

    .btn {
        margin: 0 10px 0 0;
        font-size: 2rem;
        float: right;
        font-weight: 100;
        color: black;
    }
    
    .btn span {
        width: 100%;
        height: 2px;
        background-color: black;
    }
    
    #sidebtn ul {
        align-items: center;
        padding: 1rem;
        width: 100%;
        display: flex;
        flex-direction: column;
        flex-wrap: nowrap;
        margin: 3.5rem auto;
        justify-content: space-between;
    }
    
    #sidebtn li {
        margin-top: 2rem; 
        list-style-type: none;
    }

    #sidebtn li a {
        font-family: 'Roboto', sans-serif;
        color: black;
        font-weight: 500;
        font-size: 1.5rem;
        text-decoration: none;
    }

    #sidebtn li a::after {
        display: none;
    }


    #admission {
        padding: 0;
        border: none;
    }

    #sidebtn:target {
        display: block;
    }

}