/* 作品賞析分類頁：portfolio / townhouse / oldhouse 共用 */

.portfolio-collection {
    --collection-ink: #262626;
    --collection-muted: #777;
    --collection-line: #e9e6e1;
    --collection-accent: #a68b6d;
}

.portfolio-collection.container {
    padding-left: 0;
    padding-right: 0;
}

.portfolio-header {
    max-width: 820px;
    margin: 0 auto;
    padding: 44px 24px 34px;
    text-align: center;
    box-sizing: border-box;
}

.portfolio-eyebrow,
.portfolio-faq .faq-eyebrow {
    display: block;
    margin-bottom: 10px;
    color: var(--collection-accent);
    font-family: "Cinzel", serif;
    font-size: 0.68rem;
    letter-spacing: 4px;
}

.portfolio-header h1 {
    margin: 0;
    color: var(--collection-ink);
    font-size: clamp(1.8rem, 4.2vw, 2.55rem);
    font-weight: 300;
    letter-spacing: 3px;
    line-height: 1.55;
}

.portfolio-header .portfolio-lead {
    max-width: 660px;
    margin: 18px auto 0;
    color: var(--collection-muted);
    font-size: 0.9rem;
    letter-spacing: 1.2px;
    line-height: 2;
}

.filter-eyebrow {
    margin: 4px 0 16px;
    color: #aaa;
    font-size: 0.74rem;
    font-weight: 300;
    letter-spacing: 3px;
    text-align: center;
}

.filter-tabs {
    display: flex;
    position: static;
    top: auto;
    left: auto;
    z-index: auto;
    width: auto;
    height: auto;
    max-width: 920px;
    margin: 0 auto 38px;
    padding: 0 20px;
    justify-content: center;
    align-items: stretch;
    border-bottom: 1px solid var(--collection-line);
    background: transparent;
    box-sizing: border-box;
}

.filter-tab {
    display: inline-flex;
    min-height: 44px;
    margin-bottom: -1px;
    padding: 10px 16px;
    align-items: center;
    justify-content: center;
    border: 0;
    border-bottom: 2px solid transparent;
    background: transparent;
    color: #999;
    cursor: pointer;
    font-family: inherit;
    font-size: 0.78rem;
    letter-spacing: 1.8px;
    line-height: 1.4;
    text-decoration: none;
    white-space: nowrap;
    transition: color 0.2s ease, border-color 0.2s ease;
}

.filter-tab:hover,
.filter-tab:focus-visible {
    color: #4b4b4b;
}

.filter-tab.active,
.filter-tab[aria-current="page"] {
    border-bottom-color: var(--collection-accent);
    color: var(--collection-accent);
}

.portfolio-count {
    margin: 0 0 34px;
    color: #bbb;
    font-size: 0.72rem;
    letter-spacing: 1.5px;
    text-align: center;
}

.portfolio-collection .gallery-grid {
    gap: 38px 22px;
}

.portfolio-collection .gallery-item {
    border-radius: 0;
}

.portfolio-collection .gallery-item .img-box {
    margin-bottom: 0;
    border-radius: 0;
    box-shadow: none;
}

.portfolio-collection .gallery-item .text-box {
    padding: 15px 4px 4px;
}

.portfolio-collection .gallery-item .text-box h3 {
    margin: 0 0 5px;
    font-size: 1.05rem;
    font-weight: 500;
    letter-spacing: 1.5px;
}

.portfolio-collection .gallery-item:hover {
    box-shadow: none;
    transform: translateY(-4px);
}

.portfolio-collection .gallery-item.featured {
    grid-column: 1 / -1;
}

.portfolio-collection .gallery-item.featured .img-box {
    aspect-ratio: 21 / 9;
}

.portfolio-collection .gallery-item.featured .text-box h3 {
    font-size: 1.18rem;
}

.portfolio-collection .card-tags {
    gap: 6px;
}

.portfolio-collection .card-tags span {
    padding: 2px 10px;
    border: 1px solid #dedbd6;
    border-radius: 20px;
    background: transparent;
    color: #999;
    font-size: 0.7rem;
    font-weight: 400;
    letter-spacing: 0.8px;
}

.portfolio-faq {
    max-width: 820px;
    margin: 94px auto 8px;
    padding: 0 24px;
    scroll-margin-top: 120px;
}

.portfolio-faq > .faq-eyebrow {
    text-align: center;
}

.portfolio-faq > h2 {
    margin: 0;
    color: var(--collection-ink);
    font-size: clamp(1.25rem, 3vw, 1.6rem);
    font-weight: 300;
    letter-spacing: 3px;
    line-height: 1.6;
    text-align: center;
}

.portfolio-faq-subtitle {
    margin: 8px 0 32px;
    color: #999;
    font-size: 0.78rem;
    letter-spacing: 1.6px;
    line-height: 1.8;
    text-align: center;
}

.faq-item {
    margin: 0;
    padding: 0;
    border: 0;
    border-bottom: 1px solid var(--collection-line);
}

.faq-item:first-of-type {
    border-top: 1px solid var(--collection-line);
}

.faq-item summary {
    display: grid;
    min-height: 72px;
    padding: 18px 4px;
    grid-template-columns: minmax(0, 1fr) 28px;
    gap: 18px;
    align-items: center;
    color: var(--collection-ink);
    cursor: pointer;
    list-style: none;
    box-sizing: border-box;
}

.faq-item summary::-webkit-details-marker {
    display: none;
}

.faq-item summary h3 {
    margin: 0;
    font-size: 0.96rem;
    font-weight: 500;
    letter-spacing: 1.1px;
    line-height: 1.75;
}

.faq-item summary::after {
    content: "+";
    color: var(--collection-accent);
    font-size: 1.45rem;
    font-weight: 200;
    line-height: 1;
    text-align: center;
    transition: transform 0.2s ease;
}

.faq-item[open] summary::after {
    content: "−";
}

.faq-item[open] summary {
    color: var(--collection-accent);
}

.faq-answer {
    padding: 0 50px 24px 4px;
    color: #666;
    font-size: 0.86rem;
    letter-spacing: 0.8px;
    line-height: 2;
}

.faq-answer p {
    margin: 0 0 12px;
}

.faq-answer p:last-child {
    margin-bottom: 0;
}

.faq-answer strong {
    color: #333;
    font-weight: 500;
}

.faq-answer a {
    padding-bottom: 1px;
    border-bottom: 1px dashed #d1bca0;
    color: var(--collection-accent);
}

.visually-hidden {
    position: absolute !important;
    width: 1px !important;
    height: 1px !important;
    padding: 0 !important;
    margin: -1px !important;
    overflow: hidden !important;
    clip: rect(0, 0, 0, 0) !important;
    white-space: nowrap !important;
    border: 0 !important;
}

@media (max-width: 768px) {
    .portfolio-header {
        padding: 28px 22px 28px;
    }

    .portfolio-header h1 {
        font-size: clamp(1.55rem, 7vw, 2rem);
        letter-spacing: 2px;
    }

    .portfolio-header .portfolio-lead {
        margin-top: 14px;
        font-size: 0.84rem;
        line-height: 1.9;
    }

    .filter-tabs {
        max-width: 100%;
        margin-bottom: 28px;
        padding: 0 16px;
        justify-content: flex-start;
        overflow-x: auto;
        overscroll-behavior-inline: contain;
        scrollbar-width: none;
        -webkit-overflow-scrolling: touch;
    }

    .filter-tabs::-webkit-scrollbar {
        display: none;
    }

    .filter-tab {
        min-height: 42px;
        padding: 9px 14px;
        font-size: 0.76rem;
    }

    .portfolio-collection .gallery-grid {
        gap: 30px;
        padding: 0 16px;
    }

    .portfolio-collection .gallery-item.featured .img-box {
        aspect-ratio: 4 / 3;
    }

    .portfolio-faq {
        margin-top: 72px;
        padding: 0 18px;
    }

    .portfolio-faq-subtitle {
        margin-bottom: 26px;
    }

    .faq-item summary {
        min-height: 66px;
        padding: 16px 2px;
        gap: 12px;
    }

    .faq-item summary h3 {
        font-size: 0.9rem;
        letter-spacing: 0.8px;
    }

    .faq-answer {
        padding: 0 36px 22px 2px;
        font-size: 0.83rem;
    }
}

@media (prefers-reduced-motion: reduce) {
    .filter-tab,
    .faq-item summary::after,
    .portfolio-collection .gallery-item {
        transition: none;
    }
}