/* ============================================================
 * BTU Blog — public pages (index, show, category, tag)
 * Phase 04 — 2026-06-02
 * ============================================================ */

.btu-blog-shell{
    max-width: 1280px;
    margin: 0 auto;
    padding: 40px 16px 80px;
}

/* ---------- Breadcrumbs ---------- */
.btu-blog-crumbs{
    margin: 0 0 24px;
}
.btu-blog-crumbs ol{
    list-style: none;
    padding: 0; margin: 0;
    display: flex;
    flex-wrap: wrap;
    gap: 6px 4px;
    font-size: 13px;
    color: #64748b;
}
.btu-blog-crumbs li:not(:last-child)::after{
    content: '›';
    margin: 0 4px;
    color: #94a3b8;
}
.btu-blog-crumbs a{
    color: var(--btu-blue, #3f4fff);
    text-decoration: none;
}
.btu-blog-crumbs a:hover{ text-decoration: underline; }
.btu-blog-crumbs [aria-current="page"]{ color: #0f172a; font-weight: 500; }

/* ---------- Section heads ---------- */
.btu-blog-section-head{
    display: flex;
    align-items: baseline;
    justify-content: space-between;
    gap: 16px;
    margin: 0 0 22px;
    padding-bottom: 10px;
    border-bottom: 1px solid #e2e8f0;
}
.btu-blog-section-head h2{
    margin: 0;
    font-size: 22px;
    font-weight: 700;
    color: #0f172a;
}
.btu-blog-count{
    font-size: 13px;
    color: #64748b;
}

/* ---------- Hero eyebrow ---------- */
.btu-blog-hero-eyebrow{
    display: inline-block;
    margin-bottom: 8px;
    padding: 4px 14px;
    border-radius: 999px;
    background: rgba(255,255,255,.18);
    color: #fff;
    font-size: 12px;
    font-weight: 600;
    letter-spacing: .12em;
    text-transform: uppercase;
}

/* ---------- Featured grid ---------- */
.btu-blog-featured{ margin-bottom: 56px; }
.btu-blog-featured-grid{
    display: grid;
    grid-template-columns: 2fr 1fr;
    gap: 24px;
}
.btu-blog-featured-grid > .btu-blog-card:nth-child(n+2){
    /* second/third stacked in the second column */
}
@media (min-width: 992px){
    .btu-blog-featured-grid{
        grid-template-columns: 2fr 1fr;
        grid-template-rows: 1fr 1fr;
    }
    .btu-blog-featured-grid > .btu-blog-card:first-child{
        grid-row: 1 / span 2;
    }
}
@media (max-width: 768px){
    .btu-blog-featured-grid{ grid-template-columns: 1fr; }
}

/* ---------- Layout (main + sidebar) ---------- */
.btu-blog-layout{
    display: grid;
    grid-template-columns: minmax(0, 1fr) 320px;
    gap: 40px;
    margin-top: 8px;
}
@media (max-width: 992px){
    .btu-blog-layout{ grid-template-columns: 1fr; }
}
.btu-blog-main{ min-width: 0; }

/* ---------- Grid of cards ---------- */
.btu-blog-grid{
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(280px, 1fr));
    gap: 24px;
}
.btu-blog-grid--3{
    grid-template-columns: repeat(3, 1fr);
}
@media (max-width: 768px){
    .btu-blog-grid--3{ grid-template-columns: 1fr; }
}

/* ---------- Card ---------- */
.btu-blog-card{
    background: #fff;
    border: 1px solid #e2e8f0;
    border-radius: 14px;
    overflow: hidden;
    display: flex;
    flex-direction: column;
    transition: transform .18s ease, box-shadow .18s ease, border-color .18s ease;
}
.btu-blog-card:hover{
    transform: translateY(-3px);
    border-color: rgba(63, 79, 255, .35);
    box-shadow: 0 14px 32px rgba(15, 23, 42, .08);
}
.btu-blog-card-img{
    display: block;
    position: relative;
    aspect-ratio: 16/9;
    overflow: hidden;
    background: #e2e8f0;
}
.btu-blog-card-img img{
    width: 100%; height: 100%;
    object-fit: cover;
    transition: transform .35s ease;
}
.btu-blog-card:hover .btu-blog-card-img img{ transform: scale(1.04); }
.btu-blog-card-cat{
    position: absolute;
    top: 12px; left: 12px;
    padding: 4px 10px;
    background: var(--btu-blue, #3f4fff);
    color: #fff;
    font-size: 11px;
    font-weight: 600;
    border-radius: 999px;
    letter-spacing: .04em;
    text-transform: uppercase;
}
.btu-blog-card-body{
    padding: 20px 22px 22px;
    display: flex; flex-direction: column;
    gap: 10px;
    flex: 1;
}
.btu-blog-card-title{
    margin: 0;
    font-size: 18px;
    line-height: 1.35;
    font-weight: 700;
    color: #0f172a;
}
.btu-blog-card-title a{
    color: inherit; text-decoration: none;
}
.btu-blog-card-title a:hover{ color: var(--btu-blue, #3f4fff); }
.btu-blog-card-excerpt{
    margin: 0;
    color: #475569;
    font-size: 14.5px;
    line-height: 1.55;
    flex: 1;
}
.btu-blog-card-meta{
    display: flex;
    flex-wrap: wrap;
    gap: 12px;
    font-size: 12.5px;
    color: #64748b;
    padding-top: 10px;
    border-top: 1px solid #f1f5f9;
}
.btu-blog-card-meta span{ display: inline-flex; align-items: center; gap: 6px; }
.btu-blog-card-meta i{ color: var(--btu-blue, #3f4fff); font-size: 11px; }

.btu-blog-card--lg .btu-blog-card-title{ font-size: 24px; }
.btu-blog-card--lg .btu-blog-card-excerpt{ font-size: 15.5px; }

/* ---------- Pagination ---------- */
.btu-blog-pagination{
    margin-top: 36px;
    display: flex;
    justify-content: center;
}
.btu-blog-pagination nav{ display: inline-block; }
.btu-blog-pagination .pagination,
.btu-blog-pagination ul{
    display: inline-flex;
    gap: 6px;
    padding: 0; margin: 0;
    list-style: none;
}
.btu-blog-pagination .page-item .page-link,
.btu-blog-pagination a, .btu-blog-pagination span{
    display: inline-flex;
    align-items: center; justify-content: center;
    min-width: 38px; height: 38px;
    padding: 0 12px;
    border: 1px solid #e2e8f0;
    border-radius: 8px;
    background: #fff;
    color: #475569;
    font-size: 14px;
    text-decoration: none;
}
.btu-blog-pagination .page-item.active .page-link,
.btu-blog-pagination .active span{
    background: var(--btu-blue, #3f4fff);
    border-color: var(--btu-blue, #3f4fff);
    color: #fff;
}
.btu-blog-pagination .page-item.disabled .page-link,
.btu-blog-pagination .disabled span{ opacity: .5; cursor: not-allowed; }

/* ---------- Empty state ---------- */
.btu-blog-empty{
    text-align: center;
    padding: 80px 20px;
    background: #fff;
    border: 1px dashed #cbd5e1;
    border-radius: 14px;
}
.btu-blog-empty i{
    font-size: 48px;
    color: #cbd5e1;
    margin-bottom: 18px;
}
.btu-blog-empty h3{
    margin: 0 0 8px;
    color: #0f172a;
    font-size: 20px;
}
.btu-blog-empty p{
    color: #64748b;
    margin: 0 0 18px;
}

/* ============================================================
 *  Sidebar
 * ============================================================ */
.btu-blog-sidebar{
    display: flex;
    flex-direction: column;
    gap: 22px;
}
.btu-blog-side-card{
    background: #fff;
    border: 1px solid #e2e8f0;
    border-radius: 14px;
    padding: 22px;
}
.btu-blog-side-title{
    margin: 0 0 14px;
    font-size: 15px;
    font-weight: 700;
    color: #0f172a;
    display: flex; align-items: center; gap: 8px;
    padding-bottom: 10px;
    border-bottom: 1px solid #f1f5f9;
}
.btu-blog-side-title i{ color: var(--btu-blue, #3f4fff); }
.btu-blog-side-empty{ font-size: 13px; color: #94a3b8; margin: 0; }

.btu-blog-side-list{
    list-style: none; padding: 0; margin: 0;
}
.btu-blog-side-list li + li{ border-top: 1px solid #f1f5f9; }
.btu-blog-side-list a{
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: 8px 0;
    color: #334155;
    text-decoration: none;
    font-size: 14px;
}
.btu-blog-side-list a:hover{ color: var(--btu-blue, #3f4fff); }
.btu-blog-side-count{
    font-size: 11.5px;
    background: #f1f5f9;
    color: #64748b;
    padding: 2px 8px;
    border-radius: 999px;
}

.btu-blog-side-popular{
    list-style: none; padding: 0; margin: 0;
    display: flex; flex-direction: column; gap: 12px;
}
.btu-blog-side-popular a{
    display: flex;
    align-items: flex-start;
    gap: 12px;
    color: #0f172a;
    text-decoration: none;
}
.btu-blog-side-popular a:hover .btu-blog-side-pop-title{ color: var(--btu-blue, #3f4fff); }
.btu-blog-side-num{
    flex-shrink: 0;
    width: 28px; height: 28px;
    background: rgba(63,79,255,.08);
    color: var(--btu-blue, #3f4fff);
    font-weight: 700;
    font-size: 13px;
    border-radius: 8px;
    display: inline-flex; align-items: center; justify-content: center;
}
.btu-blog-side-pop-body{
    display: flex; flex-direction: column; gap: 2px;
    min-width: 0;
}
.btu-blog-side-pop-title{
    font-size: 13.5px;
    font-weight: 500;
    line-height: 1.35;
    display: -webkit-box;
    -webkit-line-clamp: 2;
    -webkit-box-orient: vertical;
    overflow: hidden;
}
.btu-blog-side-pop-meta{
    font-size: 11.5px;
    color: #94a3b8;
}

.btu-blog-side-tags{
    display: flex; flex-wrap: wrap; gap: 6px;
}
.btu-blog-side-tags a{
    font-size: 12.5px;
    background: #f1f5f9;
    color: #475569;
    padding: 5px 10px;
    border-radius: 999px;
    text-decoration: none;
    transition: background .15s ease, color .15s ease;
}
.btu-blog-side-tags a:hover{
    background: var(--btu-blue, #3f4fff);
    color: #fff;
}

.btu-blog-side-rss{
    background: linear-gradient(135deg, rgba(63,79,255,.06), rgba(63,79,255,.02));
    border-color: rgba(63,79,255,.18);
}
.btu-blog-side-rss p{
    margin: 0 0 14px;
    font-size: 13.5px;
    color: #475569;
}
.btu-blog-side-rss-btn{
    width: 100%;
    justify-content: center;
}

/* ============================================================
 *  Show page
 * ============================================================ */

/* Reading progress bar */
.btu-blog-progress{
    position: sticky;
    top: 0;
    z-index: 80;
    height: 3px;
    width: 100%;
    background: transparent;
    pointer-events: none;
}
.btu-blog-progress > span{
    display: block;
    height: 100%;
    width: 0;
    background: var(--btu-blue, #3f4fff);
    transition: width .12s linear;
}

/* Show hero */
.btu-blog-show-hero{
    background-color: #0f172a;
    background-size: cover;
    background-position: center;
    color: #fff;
    padding: 90px 0 80px;
    position: relative;
}
.btu-blog-show-hero-inner{
    max-width: 880px;
    margin: 0 auto;
    text-align: center;
}
.btu-blog-badge{
    display: inline-block;
    margin-bottom: 16px;
    padding: 5px 14px;
    border-radius: 999px;
    background: rgba(255,255,255,.16);
    color: #fff;
    font-size: 12px;
    font-weight: 600;
    letter-spacing: .08em;
    text-transform: uppercase;
    text-decoration: none;
}
.btu-blog-badge:hover{ background: rgba(255,255,255,.28); color: #fff; }
.btu-blog-show-hero h1{
    margin: 0 0 14px;
    color: #fff;
    font-size: clamp(28px, 4vw, 44px);
    font-weight: 800;
    line-height: 1.18;
}
.btu-blog-show-excerpt{
    color: rgba(255,255,255,.88);
    font-size: 17.5px;
    line-height: 1.55;
    max-width: 760px;
    margin: 0 auto 20px;
}
.btu-blog-show-meta{
    display: flex;
    flex-wrap: wrap;
    justify-content: center;
    gap: 18px;
    color: rgba(255,255,255,.78);
    font-size: 13.5px;
}
.btu-blog-show-meta span{
    display: inline-flex; align-items: center; gap: 6px;
}

/* Article container */
.btu-blog-article{
    background: #fff;
    border: 1px solid #e2e8f0;
    border-radius: 16px;
    padding: 36px 40px 48px;
}
@media (max-width: 768px){
    .btu-blog-article{ padding: 22px 18px 32px; }
}

/* Share row */
.btu-blog-share{
    display: flex;
    flex-wrap: wrap;
    align-items: center;
    gap: 8px;
    padding: 0 0 22px;
    margin-bottom: 28px;
    border-bottom: 1px solid #f1f5f9;
}
.btu-blog-share-label{
    font-size: 13px;
    font-weight: 600;
    color: #475569;
    margin-right: 4px;
}
.btu-blog-share-label i{ color: var(--btu-blue, #3f4fff); margin-right: 4px; }
.btu-blog-share-btn{
    width: 36px; height: 36px;
    display: inline-flex; align-items: center; justify-content: center;
    border-radius: 50%;
    background: #f1f5f9;
    color: #475569;
    text-decoration: none;
    border: none;
    cursor: pointer;
    transition: transform .15s ease, background .15s ease, color .15s ease;
}
.btu-blog-share-btn:hover{
    transform: translateY(-2px);
    color: #fff;
}
.btu-share-fb:hover{ background: #1877f2; }
.btu-share-tw:hover{ background: #000; }
.btu-share-li:hover{ background: #0a66c2; }
.btu-share-wa:hover{ background: #25d366; }
.btu-share-copy:hover{ background: var(--btu-blue, #3f4fff); }
.btu-share-copy.is-copied{ background: #22c55e; color: #fff; }

/* Article body — rendered Markdown */
.btu-blog-body{
    font-size: 16.5px;
    line-height: 1.75;
    color: #334155;
}
.btu-blog-body > *:first-child{ margin-top: 0; }
.btu-blog-body h2{
    margin: 2.2em 0 .8em;
    font-size: 26px;
    font-weight: 700;
    color: #0f172a;
    line-height: 1.3;
}
.btu-blog-body h3{
    margin: 1.8em 0 .6em;
    font-size: 21px;
    font-weight: 700;
    color: #0f172a;
}
.btu-blog-body h4{
    margin: 1.5em 0 .5em;
    font-size: 18px;
    font-weight: 600;
    color: #0f172a;
}
.btu-blog-body p{
    margin: 0 0 1.3em;
}
.btu-blog-body a{
    color: var(--btu-blue, #3f4fff);
    text-decoration: underline;
    text-underline-offset: 3px;
}
.btu-blog-body a:hover{ color: #1e2742; }
.btu-blog-body ul, .btu-blog-body ol{
    margin: 0 0 1.3em 1.5em;
    padding-left: 0;
}
.btu-blog-body li{ margin-bottom: .4em; }
.btu-blog-body blockquote{
    border-left: 4px solid var(--btu-blue, #3f4fff);
    background: rgba(63,79,255,.04);
    padding: 14px 22px;
    margin: 1.6em 0;
    color: #475569;
    font-style: italic;
    border-radius: 0 8px 8px 0;
}
.btu-blog-body blockquote p:last-child{ margin-bottom: 0; }
.btu-blog-body code{
    background: #f1f5f9;
    color: #be185d;
    padding: 2px 6px;
    border-radius: 4px;
    font-size: .9em;
    font-family: 'JetBrains Mono', 'Menlo', monospace;
}
.btu-blog-body pre{
    background: #0f172a;
    color: #e2e8f0;
    padding: 18px 22px;
    border-radius: 10px;
    overflow-x: auto;
    margin: 1.6em 0;
    font-size: 14px;
    line-height: 1.6;
}
.btu-blog-body pre code{
    background: transparent;
    color: inherit;
    padding: 0;
}
.btu-blog-body img{
    max-width: 100%;
    height: auto;
    border-radius: 10px;
    margin: 1.6em 0;
}
.btu-blog-body table{
    width: 100%;
    border-collapse: collapse;
    margin: 1.6em 0;
    font-size: 14.5px;
}
.btu-blog-body th, .btu-blog-body td{
    border: 1px solid #e2e8f0;
    padding: 8px 12px;
    text-align: left;
}
.btu-blog-body th{
    background: #f8fafc;
    font-weight: 700;
    color: #0f172a;
}
.btu-blog-body hr{
    border: 0;
    border-top: 1px solid #e2e8f0;
    margin: 2em 0;
}

/* Tags after body */
.btu-blog-tags{
    margin: 36px 0 0;
    padding: 24px 0 0;
    border-top: 1px solid #f1f5f9;
    display: flex;
    flex-wrap: wrap;
    gap: 8px;
}
.btu-blog-tag-chip{
    font-size: 13px;
    background: #f1f5f9;
    color: #475569;
    padding: 6px 12px;
    border-radius: 999px;
    text-decoration: none;
    transition: background .15s, color .15s;
}
.btu-blog-tag-chip:hover{
    background: var(--btu-blue, #3f4fff);
    color: #fff;
}

/* Author bio */
.btu-blog-author-bio{
    margin: 36px 0 0;
    padding: 24px;
    background: #f8fafc;
    border-radius: 12px;
    display: flex;
    align-items: flex-start;
    gap: 18px;
}
.btu-blog-author-avatar{
    flex-shrink: 0;
    width: 64px; height: 64px;
    border-radius: 50%;
    background: linear-gradient(135deg, var(--btu-blue, #3f4fff), #1e2742);
    color: #fff;
    display: inline-flex; align-items: center; justify-content: center;
    font-size: 30px;
}
.btu-blog-author-info h4{
    margin: 0 0 6px;
    font-size: 16px;
    font-weight: 700;
    color: #0f172a;
}
.btu-blog-author-info p{
    margin: 0;
    font-size: 13.5px;
    color: #64748b;
    line-height: 1.55;
}

/* Related (sit *outside* the article card) */
.btu-blog-related{
    margin-top: 48px;
}