* {
    box-sizing: border-box;
}

body {
    padding: 10px;
    margin: 0;
}

h1, ul {
    margin: 0;
}

header {
    width: 100%;
    border: 1px solid black;
    padding: 10px;
}

.img {
    width: 100%;
}

main {
    width: 100%;
    border: 1px solid black;
    padding: 10px;
    margin-top: 10px;
    display: flex;
    justify-content: center;
    align-items: center;
    gap: 10px;
    flex-direction: column;
}

#con01_div {
    display: flex;
    justify-content: center;
    align-items: center;
    flex-direction: column;
    gap: 10px;
}

#con02_div {
    display: flex;
    justify-content: center;
    align-items: center;
    flex-direction: column;
    gap: 10px;
}

#con03_div {
    display: flex;
    justify-content: center;
    align-items: center;
    flex-direction: column;
    gap: 10px;
}

footer {
    width: 100%;
    height: 50px;
    border: 1px solid black;
    margin-top: 10px;
    padding: 10px;
    display: flex;
    justify-content: center;
    align-items: center;
}

#ad_div {
    width: 100%;
    overflow: hidden;
}

.inner-container {
    width: 400%;
    height: 100%;
    display: flex;
    justify-content: center;
    align-items: flex-start;
    animation: slider 5s ease-in-out infinite;
}

.inner-container > * {
    width: 25%;
}

@keyframes slider {
    33% {
        transform: translate(-25%, 0);
    }
    67% {
        transform: translate(-50%, 0);
    }
    100% {
        transform: translate(-75%, 0);
    }
}

#article_div {
    display: flex;
    justify-content: center;
    align-items: center;
    flex-direction: column;
    gap: 10px;
    margin-top: 10px;
}

nav a {
    text-decoration: none;
}

nav ul {
    list-style: none;
    padding-left: 0;
}

.menu {
    clear: both;
    background: #fff;
    max-height: 0;
    overflow: hidden;
    transition: .5s max-height linear;
}

.menu li {
    text-align: center;
    border-bottom: 1px solid #eee;
}

.menu a {
    display: block;
    padding: 10px 0;
    color: black;
}

#nav_switch {
    display: none;
}

#nav-hamburger {
    float: right;
    margin-top: -25px;
}

#nav_switch:checked ~ .menu {
    max-height: 150px;
}

.nav-icon {
    border-top: 1px solid black;
    width: 20px;
    display: inline-block;
    padding: 10px 0;
    position: relative;
}

.nav-icon::before {
    border-top: 1px solid black;
    width: 20px;
    position: absolute;
    top: 50%;
    left: 0;
    content: '';
}

.nav-icon::after {
    border-top: 1px solid black;
    width: 20px;
    position: absolute;
    bottom: 0;
    left: 0;
    content: '';
}

@media screen and (min-width: 481px) {
    #con01_div {
        flex-direction: row;
    }
    #con01_div > *, #con02_div > *, #con03_div > * {
        width: 49.5%;
    }

    #con02_div, #con03_div {
        flex-direction: row;
    }
}

@media screen and (min-width: 1025px) {
    #article_div {
        width: 66%;
        margin-top: 0;
    }

    #con01_div {
        width: 33%;
        flex-direction: column;
        gap: 10px;
    }

    #content_div {
        display: flex;
        justify-content: center;
        align-items: center;
        gap: 10px;
    }
    #con01_div > *{
        width: 100%;
    }

    .menu li {
        display: inline-block;
    }

    #nav-hamburger {
        display: none;
    }

    .menu {
        max-height: 50px;
    }

    nav {
        display: flex;
        justify-content: space-between;
        align-items: center;
    }

}