.letter__container{
    width: calc(345%/var(--width-sp)*100);
    margin-inline: auto;
    margin-top: 87px;
    margin-bottom: 80px;
    display: flex;
    flex-direction: column;
    gap: 32px;
}
@media(min-width:960px){
    .letter__container{
        max-width: 1320px;
        margin-top: 120px;
        margin-bottom: 120px;
        flex-direction: row;
    }
}

.letter__article{
    color: var(--sub-text-color);
    padding: 32px 15px 64px;
    background-color: var(--white);
    border-radius: 30px;
}
@media(min-width:960px){
    .letter__article{
        padding: 32px 32px 64px;
        border-radius: 40px;
        flex: 1;
    }
}

.letter__article-heading{
    border-bottom: 1px solid var(--sub-text-color);
    padding-bottom: 12px;
    margin-bottom: 24px;
}
@media(min-width:960px){
    .letter__article-heading{
        border-bottom: 2px solid var(--sub-text-color);
        margin-bottom: 32px;
    }
}

.letter__taxonomy{
    display: flex;
    flex-direction: column;
    gap: 12px;
    margin-bottom: 12px;
}
@media(min-width:960px){
    .letter__taxonomy{
        flex-direction: row;
        justify-content: space-between;
        align-items: end;
    }
}

.letter__enn{
    padding-left: 28px;
    line-height: 1.2;
    letter-spacing: 0.1em;
    position: relative;
}
@media(min-width:960px){
    .letter__enn{
        font-size: 18px;
    }
}
.letter__enn::before{
    content: "";
    display: block;
    width: 14px;
    aspect-ratio: 1;
    background-image: url(../images/icon/pen.svg);
    background-size: contain;
    position: absolute;
    top: 0;
    left: 0;
}
@media(min-width:960px){
    .letter__enn::before{
        width: 16px;
    }
}

.letter__date{
    font-size: 12px;
    line-height: 1.2;
    letter-spacing: 0.1em;
}
@media(min-width:960px){
    .letter__date{
        font-size: 14px;
    }
}

.letter__title{
    font-size: 20px;
    line-height: 1.2;
    letter-spacing: 0.1em;
}
@media(min-width:960px){
    .letter__title{
        font-size: 32px;
    }
}

.letter__image{
    aspect-ratio: 1 / 0.762;
    border-radius: 30px;
    overflow: hidden;
    margin-bottom: 24px;
}
@media(min-width:960px){
    .letter__image{
        max-width: 640px;
        margin-inline: auto;
        aspect-ratio: 1 / 0.5;
        border-radius: 40px;
        margin-bottom: 32px;
    }
}


.letter__text-container{
    margin-bottom: 62px;
}
.letter__paragraph{
    margin-bottom: 36px;
}

.letter__paragraph br {
    display: block;
    content: "";
    margin-bottom: 5px;
}

.letter__h3{
    padding-left: 16px;
    line-height: 2;
    letter-spacing: 0.1em;
    margin-bottom: 8px;
    position: relative;
}
.letter__h3::before{
    content: "";
    display: block;
    width: 4px;
    height: 100%;
    border-radius: 2px;
    background-color: var(--pink);
    position: absolute;
    top: 0;
    left: 0;
}

.letter__text{
    line-height: 2;
    letter-spacing: 0.1em;
}

.letter__btn{
    --btn-width-S: var(--btn-width-L);
    color: var(--text-color);
}
@media(max-width:374px){
    .letter__btn{
        --btn-width-S: 240px;
        font-size: 14px;
    }
}
.letter__taxonomy-container{
    padding: 12px 0 0 12px;
    border-top: 1px solid var(--text-color);
}
@media(min-width:960px){
    .letter__taxonomy-container{
        padding: 12px 0 0 24px;
        width: 328px;
        border-top: unset;
        border-left: 1px solid var(--text-color);
    }
}

.letter__taxonomy-title{
    font-size: 20px;
    line-height: 1.5;
    letter-spacing: 0.2em;
    margin-bottom: 10px;
}
@media(min-width:960px){
    .letter__taxonomy-title{
        font-size: 24px;
        line-height: 1.5;
        letter-spacing: 0.2em;
        margin-bottom: 10px;
    }
}

.letter__taxonomy-month-container{
    padding-left: 8px;
    display: flex;
    flex-wrap: wrap;
    gap: 12px 18px;
}

.letter__taxonomy-yearly{
    margin-bottom: 10px;
}

.letter__taxonomy-year{
    font-size: 14px;
    line-height: 1.5;
    letter-spacing: 0.1em;
    padding-left: 18px;
    margin-bottom: 10px;
    position: relative;
}
@media(min-width:960px){
    .letter__taxonomy-year{
        font-size: 16px;
    }
}
.letter__taxonomy-year::before{
    content: "";
    display: block;
    width: 4px;
    height: 100%;
    border-radius: 2px;
    background-color: var(--pink);
    position: absolute;
    top: 0;
    left: 4px;
}

.letter__taxonomy-monthly a{
    padding: 4px 12px;
    background-color: var(--white);
    border-radius: 8px;
    font-size: 12px;
    letter-spacing: 0.1em;
}
@media(min-width:960px){
    .letter__taxonomy-monthly a{
        font-size: 14px;
    }
}

/* archive-letter */

.letter__archive{
    container-type: inline-size;
    margin-top: -3px;
}
@media(min-width:960px){
    .letter__archive{
        flex: 1;
        margin-top: 2px;
    }
}
.letter__archive-h2{
    font-size: 20px;
    padding-left: 26px;
    line-height: 1.2;
    letter-spacing: 0.1em;
    margin-bottom: 8px;
    position: relative;
}
.letter__archive-h2::before{
    content: "";
    display: block;
    width: 18px;
    aspect-ratio: 1;
    background-image: url(../images/icon/glass-solid.svg);
    background-size: contain;
    position: absolute;
    top: 0;
    left: 0;
}
@media(min-width:768px){
    .letter__archive-h2{
        font-size: 24px;
        padding-left: 32px;
    }
    .letter__archive-h2::before{
        width: 20px;
    }
}

.letter__filter-container{
    padding-bottom: 12px;
    border-bottom: 1px solid var(--text-color);
    display: flex;
    align-items: center;
    flex-wrap: wrap;
    gap: 8px;
    margin-bottom: 32px;
}
@media(min-width:960px){
    .letter__filter-container{
        border-bottom: 2px solid var(--text-color);
    }
}
.letter__filter-select-box{
    display: inline-block;
    font-size: 14px;
    color: var(--sub-text-color);
    line-height: 1.2;
    letter-spacing: 0.1em;
    height: 36px;
    padding-left: 16px;
    background-color: var(--white);
    border: 1px solid var(--sub-text-color);
    border-radius: 8px;
    align-content: center;
    position: relative;
}
.letter__filter-select-box::after{
    content: "";
    display: block;
    width: 11.2px;
    aspect-ratio: 1.75 / 1;
    background-image: url(../images/icon/arrow.svg);
    background-size: contain;
    background-repeat: no-repeat;
    background-position: center;
    position: absolute;
    top: 50%;
    right: 16.8px;
    translate: 0 -50%;
}
.letter__filter-select-box.selected::after{
    display: none;
}

@media(min-width:960px){
    .letter__filter-select-box{
        font-size: 16px;
    }
}
.letter__filter-select--prefecture{
    width: 240px;
}
.letter__filter-select--enn{
    width: 200px;
}
.letter__filter-select{
    letter-spacing: 0.1em;
}
.letter__filter-button{
    display: inline-block;
    width: 36px;
    aspect-ratio: 1;
    background-image: url(../images/icon/glass.svg);
    background-size: contain;

}
.p-filter__button-item.p-filter__button-item--submit{
    width: 100%;
    height: 100%;
}
.letter__archive-ul{
    padding-inline: 22.5px;
    display: flex;
    flex-direction: column;
    gap: 20px;
}
@container(min-width:500px){
    .letter__archive-ul{
        padding-inline: unset;
        display: grid;
        grid-template-columns: repeat(2, 1fr);
        gap: 30px;
    }
}
@container(min-width:800px){
    .letter__archive-ul{
        grid-template-columns: repeat(3, 1fr);
    }
}
.letter__archive-li a{
    overflow: hidden;
    border-radius: 20px;
    background-color: var(--white);
    color: var(--sub-text-color);
    line-height: 1.5;
    display: flex;
    flex-direction: column;
}

.letter__archive-image{
    aspect-ratio: 1 / 0.45;
    overflow: hidden;
}
.letter__archive-text-box{
    padding: 12px 12px 25px;
    display: flex;
    flex-direction: column;
    gap: 12px;
    flex-grow: 1;
}
@media(min-width:768px){
    .letter__archive-text-box{
        padding: 12px;
    }
}
.letter__archive-hgroup{
    flex-grow: 1;
}
.letter__archive-enn{
    margin-bottom: 12px;
    letter-spacing: 0.04em;
}
.letter__archive-title{
    font-size: 14px;
    letter-spacing: 0.04em;
}
.letter__archive-date{
    font-size: 12px;
    text-align: right;
    letter-spacing: 0.04em;
}
@media(min-width:768px){
    .letter__archive-enn{
        font-size: 18px;
    }
    .letter__archive-title{
        font-size: 16px;
    }
    .letter__archive-date{
        font-size: 14px;
    }
}