@media screen and (max-width: 560px) {

    body {
        line-height: 1.5;
    }

    .content-section p,
    .update-list,
    .attention-list,
    .info-table,
    .tweet-content,
    .novel-list {
        font-size: 13px;
    }

    .site-header {
        padding: 80px 20px 60px 20px;
    }

    .site-header h1 {
        font-size: 2.6rem;
    }

    .site-header p {
        font-size: 1.1rem;
        margin-top: 2px;
    }

    .font-deco::before,
    .font-deco::after {
        font-size: 1.2rem;
    }

    .container {
        width: 98%;
    }

    /* 見出し */
    .content-section h2 {
        font-size: 1.15rem;
        margin-bottom: 15px;
        letter-spacing: 0.15em;
    }

    .content-section {
        padding: 35px 20px 25px;
        margin-top: 25px;
        max-width: 500px;
    }

    .content-section::before {
        width: 100px;
        height: 32px;
        top: -15px;
    }

    .nav-menu ul {
        gap: 4px 12px;
        flex-wrap: wrap;
        justify-content: center;
    }

    .nav-menu a {
        font-size: 13px;
        padding: 4px 0;
        letter-spacing: 0.07em;
    }

    .info-table th,
    .info-table td {
        display: block;
        width: 100%;
        padding: 4px 0;
    }

    .info-table th {
        border-bottom: none;
        padding-top: 10px;
        color: var(--color-primary);
        font-size: 12px;
    }

    .info-table td {
        padding-bottom: 10px;
    }

    .info-table tr:last-child td {
        border-bottom: 1px solid var(--color-border);
    }

    ul.bookmark-list {
        gap: 8px 16px;
    }

    .mail-form {
        gap: 10px;
    }

    .mail-textarea {
        height: 80px;
    }

    .mail-submit-btn {
        width: 100%;
        padding: 8px 20px;
    }

    .name-form-inner {
        display: flex;
        flex-direction: row;
        flex-wrap: nowrap;
        align-items: center;
        gap: 6px;
    }

    .name-form-inner h3 {
        display: none;
    }

    .input-group {
        font-size: 12px;
    }

    #save-btn {
        padding: 5px 12px;
        font-size: 12px;
    }

    #totop-btn {
        bottom: 20px;
        right: 20px;
        width: 42px;
        height: 42px;
        font-size: 1.1rem;
    }
}