body {
    margin: 0;
    background-color: white;
    font-family: Arial, sans-serif;
}

.site-header {
    border-bottom: 3px solid #08aeea;
    padding: 10px 60px 0;
    margin: 0 auto;
    max-width: 1000px;
}

.site-header h1 {
    font-size: 80px;
    margin: 0;
    line-height: 1.2;
    padding-top: 20px;
}

.link-buttons {
    display: flex;
    justify-content: center;
    margin: 30px 20px;
}

.link-button {
    display: block;
    background-color: #08aeea;
    color: white;
    text-decoration: none;
    text-align: center;
    padding: 8px 20px;
    font-size: 30px;
    min-width: 450px;
}

.link-button:hover {
    background-color: #0798cc;
}
.video-section {
    display: flex;
    justify-content: center;
    margin: 25px 20px;
}

.video-thumbnail {
    display: block;
    width: 560px;
    max-width: 100%;
    height: auto;
}

/* スマートフォン用の設定 */
@media screen and (max-width: 600px) {

    .site-header {
        padding: 10px 20px 0;
    }

    .site-header h1 {
        font-size: 56px;

    }

    .link-buttons {
        margin: 25px 15px;
    }

    .link-button {
        box-sizing: border-box;
        width: 100%;
        min-width: 0;
        font-size: 18px;
        padding: 12px 10px;
        white-space: nowrap;
    }

    .video-section {
        margin: 25px 15px;
    }

   .video-thumbnail {
    width: 100%;
    height: auto;
}

}