.spg {
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 20px;
    font-family: 'Noto Serif JP', 'Yu Mincho', 'Hiragino Mincho ProN', serif;
    line-height: 1.8;
    color: #333;
    font-weight: 400;
}
.spg .spg-title {
    font-size: 42px;
    font-weight: 400;
    color: #000;
    margin-bottom: 10px;
    letter-spacing: 0.02em;
}

.spg .spg-subtitle {
    font-size: 15px;
    color: #666;
    font-weight: 300;
    letter-spacing: 0.1em;
}

.spg .spg-header {
    background: #fff;
    padding: 60px 0 50px;
    text-align: center;
    border-bottom: 1px solid #e5e5e5;
}

.spg .spg-nav-container {
    background: #f8f8f8;
    margin: 30px auto;
    max-width: 1000px;
    border: 1px solid #e0e0e0;
}

.spg .spg-nav-desktop {
    display: grid;
    grid-template-columns: repeat(2, 1fr);
}

.spg .spg-nav-item {
    display: block;
    padding: 15px 25px;
    background: #f8f8f8;
    text-decoration: none;
    color: #333;
    transition: all 0.2s ease;
    font-weight: 300;
    font-size: 15px;
    letter-spacing: 0.02em;
    border-bottom: 1px solid #e0e0e0;
    border-right: 1px solid #e0e0e0;
}

.spg .spg-nav-desktop .spg-nav-item:nth-child(2n) {
    border-right: none;
}

.spg .spg-nav-desktop .spg-nav-item:nth-last-child(-n+2) {
    border-bottom: none;
}

.spg .spg-nav-item:hover {
    background: #fff;
}

.spg .spg-nav-item.current {
    background: #fff;
    font-weight: 400;
    box-shadow: inset 3px 0 0 0 #333;
}

.spg .spg-mobile-toggle {
    display: none;
    width: 100%;
    padding: 20px;
    background: #f8f8f8 !important;
    color: #333 !important;
    border: none;
    border-bottom: 1px solid #e0e0e0;
    font-size: 16px;
    font-weight: 400;
    cursor: pointer;
    text-align: left;
    position: relative;
    font-family: inherit;
    -webkit-appearance: none;
    -moz-appearance: none;
    appearance: none;
}

.spg .spg-mobile-toggle::after {
    content: '▼';
    position: absolute;
    right: 20px;
    transition: transform 0.3s ease;
    color: #666 !important;
    font-size: 14px;
}

.spg .spg-mobile-toggle.active::after {
    transform: rotate(180deg);
}

.spg .spg-nav-mobile {
    display: none;
    background: #fff;
}
https://cms.digitalatelier.jp/WebRelease2/img.-.ja_1713172896@@@w-pagerelease.gif
.spg .spg-nav-mobile.active {
    display: block;
}

.spg .spg-nav-mobile .spg-nav-item {
    border-right: none;
    border-bottom: 1px solid #e0e0e0;
    background: #fff;
}

@media (max-width: 768px){
    .spg {
        padding: 0 15px;
    }
    .spg .spg-title {
        font-size: 28px;
        font-weight: 400;
        letter-spacing: 0;
    }
    .spg .spg-subtitle {
        font-size: 13px;
    }
    .spg .spg-header {
        padding: 30px 0 25px;
    }
    .spg .spg-nav-container {
        margin: 20px 0;
        background: #fff;
    }

    .spg .spg-nav-desktop {
        display: none;
    }

    .spg .spg-mobile-toggle {
        display: block;
        font-size: 15px;
        background-color: #f8f8f8 !important;
        color: #333 !important;
        padding: 15px 20px;
    }

   .spg .spg-nav-mobile.active {
       display: block;
   }
   .spg .spg-subtitle{
       margin-bottom: 0
   }
}