* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

.container {
    max-width: 1500px;
    margin: 0 auto;
}

header {
    background-color: #333;
    color: white;
    padding: 20px 0;
}

.logo {
    float: left;
    width: 35%;
}

.logo h1 {
    font-size: 1.5em;
    margin-left: 10px;
}

nav {
    float: right;
    width: 65%;
}

nav ul {

    text-align: right;
}

nav ul li {
    display: inline-block;
    margin-left: 20px;
    position: relative;
}

nav ul li a {
    color: red;
    text-decoration: none;
    padding: 20px;
    font-size: 20px;
}

nav ul li a:hover {
    text-decoration: underline;
}

.clear {
    clear: both;
}

.sidebar {
    width: 200px;
    background-color: whitesmoke;
    padding-top: 20px;
    height: 1000px;
    top: 130px;
    float: left;
    bottom: 0;
    font-size: 20px;
}

.sidebar .active {
    background-color: rgb(107, 110, 113);
}

.sidebar ul li {
    margin: 20px 0;
    padding: 10px;
    /* float: left; */
    list-style: none;
}

.sidebar ul li a {
    color: rgb(117, 11, 90);
    display: block;
    padding: 30px;
}

.flex-container {
    border: 3px solid grey;
    background-color: aliceblue;
    color: rgb(98, 116, 150);
    border-radius: 5px;
    width: 1000px;
    margin-left: 200px;
    /* margin-right: 300px; */
    margin-top: 20px;
    margin-bottom: 10px;
    font-size: 24px;
}

.flex-container h2 {
    font: 1em sans-serif;
    text-align: center;
    text-decoration: underline;
}

.main {
    font-family: 'Trebuchet MS', 'Lucida Sans Unicode', 'Lucida Grande', 'Lucida Sans', Arial, sans-serif;
    font-size: 22px;
}

.main h1 {
    text-align: center;
    text-decoration: underline;
}

footer {
    border: #333 solid 3px;
    background-color: #333;
    color: whitesmoke;
    text-align: center;
    justify-content: flex-end;
    margin-top: 360px;

}

.active {
    background-color: burlywood;
}

@media (max-width: 1200px) {
    .container {
        padding: 0 20px;
    }

    .logo,
    nav {
        width: 100%;
    }

    nav ul {
        padding: 0;
    }

    nav ul li {
        display: block;
    }

    .sidebar {
        width: 100%;
    }

    .flex-container {
        width: 100%;
    }

    .flex-container>div {
        width: 100%;
    }

    .main {
        width: 100%;
    }

    table {
        width: 100%;
    }

    #item1 {

        background-image: linear-gradient(rgb(128, 225, 128), rgb(210, 210, 45));
    }

    #item2 {
        background-image: linear-gradient(rgb(216, 99, 213), rgb(137, 205, 232));
    }

    #item3 {
        background-image: linear-gradient(rgb(60, 60, 162), rgb(237, 91, 91), yellow);
    }

    #item4 {
        background-image: linear-gradient(brown, yellow, pink);
    }
}

@media (min-width: 600px) {
    header {
        padding: 10px 0;
    }

    .logo h1 {
        font-size: 1.2em;
    }

    nav ul li a {
        padding: 10px;
    }

    .sidebar ul li a {
        padding: 20px;

    }

    .flex-container>div {
        font-size: 24px;

    }

    .main h2 {
        font-size: 1em;

    }

    tbody {
        font-size: 18px;
    }

    #item1 {

        background-image: linear-gradient(rgb(128, 225, 128), rgb(210, 210, 45));
    }

    #item2 {
        background-image: linear-gradient(rgb(216, 99, 213), rgb(137, 205, 232));
    }

    #item3 {
        background-image: linear-gradient(rgb(60, 60, 162), rgb(237, 91, 91), yellow);
    }

    #item4 {
        background-image: linear-gradient(brown, yellow, pink);
    }

}