/* ===== theme611 蔬果种植百科库 common.css (B 骨架 bt-*) ===== */
:root {
    --color-primary: #f59e0b;
    --color-primary-dark: #b45309;
    --color-primary-light: #fffbeb;
    --color-text-dark: #78350f;
    --color-text-muted: #8a6d3b;
    --color-text-light: #b9a37a;
    --color-bg-gray: #fdf6e9;
    --color-border: #f0e3c8;
    --radius-sm: 4px;
    --radius-md: 10px;
    --radius-lg: 14px;
    --shadow-sm: 0 1px 3px rgba(180, 83, 9, 0.08);
    --shadow-md: 0 6px 18px rgba(180, 83, 9, 0.12);
    --font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei", sans-serif;
}

/* ===== 基础 ===== */
body { font-family: var(--font-family); color: var(--color-text-dark); background: #fff; margin: 0; line-height: 1.7; }
a { color: var(--color-primary-dark); text-decoration: none; }
a:hover { color: var(--color-primary-dark); text-decoration: underline; }
img { max-width: 100%; }
.container { max-width: 1200px; }
.bt-container { padding: 30px 15px; }
h1, h2, h3, h4 { font-weight: 700; line-height: 1.4; }

/* A11y */
.bt-skip, .skip-link { position: absolute; top: -50px; left: 8px; z-index: 9999; padding: 10px 18px; background: var(--color-primary); color: #fff !important; border-radius: 0 0 6px 6px; font-size: 14px; transition: top 0.2s ease-out; }
.bt-skip:focus, .skip-link:focus { top: 0; outline: 3px solid #fff; outline-offset: 1px; }
a:focus-visible, button:focus-visible, input:focus-visible, textarea:focus-visible, [tabindex]:focus-visible { outline: 2px solid var(--color-primary); outline-offset: 2px; border-radius: 3px; }

/* ===== 顶部导航（B 骨架：Bootstrap navbar） ===== */
.bt-navbar { background: #fff; border-bottom: 2px solid var(--color-primary); margin-bottom: 0; min-height: 60px; }
.bt-navbar .navbar-brand.bt-logo { display: flex; align-items: center; gap: 8px; padding-top: 10px; }
.bt-logo img { height: 34px; width: auto; }
.bt-logo-text { font-size: 20px; font-weight: 800; color: var(--color-primary-dark); letter-spacing: 0.5px; }
.bt-menu > li > a { font-size: 15px; color: var(--color-text-dark); padding: 19px 14px; }
.bt-menu > li > a:hover, .bt-menu > li.active > a { color: var(--color-primary-dark); background: var(--color-primary-light); }
/* 子菜单 hover 显示 */
.bt-menu .dropdown { position: relative; }
.bt-menu .dropdown:hover > .dropdown-menu { display: block; }
.bt-menu .dropdown-menu { border-radius: var(--radius-sm); border: 1px solid var(--color-border); }
.bt-menu .dropdown-menu > li > a { padding: 8px 16px; font-size: 14px; color: var(--color-text-dark); }
.bt-menu .dropdown-menu > li > a:hover { background: var(--color-primary-light); color: var(--color-primary-dark); }

/* ===== 页脚（B 骨架：3 列 + 版权） ===== */
.bt-foot { background: var(--color-text-dark); color: #f6e3c3; margin-top: 40px; }
.bt-foot-cols { padding: 40px 0 20px; }
.bt-col h3 { font-size: 15px; color: #fff; margin: 0 0 14px; }
.bt-col p { font-size: 13px; color: #d8bd8f; line-height: 1.8; }
.bt-logo .bt-logo-text { color: #fff; }
.bt-foot-nav { list-style: none; margin: 0; padding: 0; }
.bt-foot-nav li { margin-bottom: 8px; }
.bt-foot-nav a { font-size: 13px; color: #d8bd8f; }
.bt-foot-nav a:hover { color: #fff; }
.bt-foot-tags a { display: inline-block; font-size: 13px; color: #d8bd8f; margin: 0 8px 8px 0; padding: 3px 10px; border: 1px solid rgba(255,255,255,0.18); border-radius: 999px; }
.bt-foot-tags a:hover { color: #fff; border-color: var(--color-primary); text-decoration: none; }
.bt-copy { margin-top: 20px; padding-top: 16px; border-top: 1px solid rgba(255,255,255,0.1); font-size: 12px; color: #c4a87e; text-align: center; }

/* ===== 面包屑页头 ===== */
.bt-banner { background: var(--color-primary-light); border-bottom: 1px solid var(--color-border); }
.bt-banner .container { padding: 24px 15px; }
.bt-banner-title { font-size: 24px; margin: 0 0 8px; }
.bt-crumb { font-size: 13px; color: var(--color-text-muted); }
.bt-crumb a { color: var(--color-primary-dark); }
.bt-crumb i { margin: 0 6px; }

/* ===== 首页：置顶大卡 ===== */
.bt-top { padding-top: 30px; }
.bt-top-card { display: flex; gap: 24px; background: #fff; border: 1px solid var(--color-border); border-radius: var(--radius-lg); overflow: hidden; box-shadow: var(--shadow-sm); transition: box-shadow 0.25s; }
.bt-top-card:hover { box-shadow: var(--shadow-md); text-decoration: none; }
.bt-top-cover { width: 46%; min-height: 260px; position: relative; overflow: hidden; background: var(--color-primary-light); display: flex; align-items: center; justify-content: center; }
.bt-top-cover img { position: absolute; inset: 0; width: 100%; height: 100%; object-fit: cover; }
.bt-top-cover > span { font-size: 84px; }
.bt-top-body { flex: 1; min-width: 0; padding: 24px 26px; }
.bt-top-tag { display: inline-block; background: var(--color-primary); color: #fff; font-size: 12px; font-weight: 600; padding: 3px 10px; border-radius: 999px; margin-bottom: 12px; }
.bt-top-body h1 { font-size: 26px; margin: 0 0 12px; }
.bt-top-body p { font-size: 14px; color: var(--color-text-muted); margin: 0 0 14px; display: -webkit-box; -webkit-line-clamp: 3; -webkit-box-orient: vertical; overflow: hidden; }
.bt-top-meta { font-size: 13px; color: var(--color-text-light); }

/* ===== 区块 ===== */
.bt-block { padding: 34px 0 0; }
.bt-block-head { display: flex; align-items: center; justify-content: space-between; border-bottom: 2px solid var(--color-primary); padding-bottom: 10px; margin-bottom: 20px; }
.bt-block-head h2 { font-size: 20px; margin: 0; }
.bt-more { font-size: 13px; color: var(--color-primary-dark); }

/* 分类快速入口 */
.bt-cats { display: grid; grid-template-columns: repeat(2, 1fr); gap: 18px; }
.bt-cat-card { display: flex; align-items: center; gap: 16px; padding: 22px 24px; background: #fff; border: 1px solid var(--color-border); border-radius: var(--radius-md); transition: box-shadow 0.25s, transform 0.25s; }
.bt-cat-card:hover { box-shadow: var(--shadow-md); transform: translateY(-3px); text-decoration: none; }
.bt-cat-ico { width: 56px; height: 56px; border-radius: var(--radius-md); background: var(--color-primary-light); display: flex; align-items: center; justify-content: center; font-size: 26px; flex-shrink: 0; }
.bt-cat-info { flex: 1; min-width: 0; }
.bt-cat-info b { display: block; font-size: 17px; color: var(--color-text-dark); margin-bottom: 4px; }
.bt-cat-info i { font-style: normal; font-size: 13px; color: var(--color-text-muted); }

/* ===== 竖卡网格（矩阵 list=vertical） ===== */
.bt-grid { display: grid; grid-template-columns: repeat(3, 1fr); gap: 20px; }
.bt-card { display: block; background: #fff; border: 1px solid var(--color-border); border-radius: var(--radius-md); overflow: hidden; transition: box-shadow 0.25s, transform 0.25s; }
.bt-card:hover { box-shadow: var(--shadow-md); transform: translateY(-3px); text-decoration: none; }
.bt-card-cover { display: block; position: relative; padding-top: 62%; background: var(--color-primary-light); overflow: hidden; }
.bt-card-cover img { position: absolute; inset: 0; width: 100%; height: 100%; object-fit: cover; }
.bt-card-cover > span { position: absolute; inset: 0; display: flex; align-items: center; justify-content: center; font-size: 44px; }
.bt-card-body { padding: 14px 16px 16px; }
.bt-card-body h3 { font-size: 15px; margin: 0 0 6px; color: var(--color-text-dark); display: -webkit-box; -webkit-line-clamp: 2; -webkit-box-orient: vertical; overflow: hidden; }
.bt-card-body p { font-size: 13px; color: var(--color-text-muted); margin: 0 0 8px; display: -webkit-box; -webkit-line-clamp: 2; -webkit-box-orient: vertical; overflow: hidden; }
.bt-card-meta { font-size: 12px; color: var(--color-text-light); }
.bt-card-cat { color: var(--color-primary-dark); font-weight: 600; }

/* ===== 文章流 ===== */
.bt-feeds { list-style: none; margin: 0; padding: 0; background: #fff; border: 1px solid var(--color-border); border-radius: var(--radius-md); overflow: hidden; }
.bt-feed { border-bottom: 1px dashed var(--color-border); }
.bt-feed:last-child { border-bottom: none; }
.bt-feed a { display: flex; align-items: center; justify-content: space-between; gap: 16px; padding: 14px 18px; }
.bt-feed a:hover { background: var(--color-primary-light); text-decoration: none; }
.bt-feed-title { flex: 1; min-width: 0; font-size: 14px; color: var(--color-text-dark); white-space: nowrap; overflow: hidden; text-overflow: ellipsis; }
.bt-feed-meta { flex-shrink: 0; font-size: 12px; color: var(--color-text-light); }

/* ===== 文章详情（矩阵 detail=centered → 居中） ===== */
.bt-article { background: #fff; border: 1px solid var(--color-border); border-radius: var(--radius-md); padding: 30px 40px; max-width: 860px; margin: 0 auto; }
.bt-article-head { margin-bottom: 20px; text-align: center; }
.bt-article-cat { display: inline-block; background: var(--color-primary-light); color: var(--color-primary-dark); font-size: 12px; font-weight: 600; padding: 3px 12px; border-radius: 999px; margin-bottom: 12px; }
.bt-article-title { font-size: 27px; margin: 0 0 12px; }
.bt-article-meta { font-size: 13px; color: var(--color-text-light); display: flex; justify-content: center; gap: 16px; }
.bt-article-content { font-size: 15px; line-height: 1.95; color: var(--color-text-dark); margin-top: 18px; max-width: 720px; margin-left: auto; margin-right: auto; }
.bt-article-content h2 { font-size: 21px; margin: 26px 0 12px; }
.bt-article-content p { margin: 0 0 14px; }
.bt-article-nav { display: flex; justify-content: space-between; gap: 16px; margin-top: 30px; padding-top: 20px; border-top: 1px solid var(--color-border); }
.bt-nav-item { display: block; flex: 1; min-width: 0; padding: 12px 16px; background: var(--color-bg-gray); border-radius: var(--radius-md); }
.bt-nav-item:hover { background: var(--color-primary-light); text-decoration: none; }
.bt-nav-label { display: block; font-size: 12px; color: var(--color-text-light); margin-bottom: 4px; }
.bt-nav-title { display: block; font-size: 14px; color: var(--color-text-dark); white-space: nowrap; overflow: hidden; text-overflow: ellipsis; }
.bt-nav-next { text-align: right; }

/* ===== 侧边栏 Widget ===== */
.bt-widget { background: #fff; border: 1px solid var(--color-border); border-radius: var(--radius-md); margin-bottom: 18px; overflow: hidden; }
.bt-widget-head { background: var(--color-primary-light); padding: 12px 16px; border-bottom: 1px solid var(--color-border); }
.bt-widget-title { font-size: 15px; margin: 0; color: var(--color-text-dark); }
.bt-widget-body { padding: 12px 16px; }
.bt-snav-list { list-style: none; margin: 0; padding: 0; }
.bt-snav-item a { display: block; padding: 8px 10px; font-size: 14px; color: var(--color-text-dark); border-radius: var(--radius-sm); }
.bt-snav-item a:hover { background: var(--color-primary-light); text-decoration: none; color: var(--color-primary-dark); }
.bt-snav-item.active a { background: var(--color-primary-light); color: var(--color-primary-dark); font-weight: 600; }
.bt-snav-divider { border-top: 1px dashed var(--color-border); margin: 6px 0; }
.bt-snav-item.bt-snav-sub a { padding-left: 24px; font-size: 13px; color: var(--color-text-muted); }
.bt-shot-list, .bt-snew-list { list-style: none; margin: 0; padding: 0; }
.bt-shot-item { display: flex; align-items: center; gap: 10px; padding: 8px 0; border-bottom: 1px dashed var(--color-border); }
.bt-shot-item:last-child { border-bottom: none; }
.bt-shot-num { flex-shrink: 0; width: 22px; height: 22px; line-height: 22px; text-align: center; font-size: 12px; font-weight: 700; color: var(--color-text-light); background: var(--color-bg-gray); border-radius: var(--radius-sm); }
.bt-shot-num.bt-shot-top { background: var(--color-primary); color: #fff; }
.bt-shot-content { flex: 1; min-width: 0; }
.bt-shot-title { display: block; font-size: 13px; color: var(--color-text-dark); white-space: nowrap; overflow: hidden; text-overflow: ellipsis; }
.bt-shot-title:hover { color: var(--color-primary-dark); text-decoration: none; }
.bt-shot-meta { font-size: 12px; color: var(--color-text-light); }
.bt-snew-item { padding: 8px 0; border-bottom: 1px dashed var(--color-border); }
.bt-snew-item:last-child { border-bottom: none; }
.bt-snew-title { display: block; font-size: 13px; color: var(--color-text-dark); white-space: nowrap; overflow: hidden; text-overflow: ellipsis; }
.bt-snew-title:hover { color: var(--color-primary-dark); text-decoration: none; }
.bt-snew-date { font-size: 12px; color: var(--color-text-light); }

/* 相关推荐（详情底部） */
.bt-related { max-width: 860px; margin: 30px auto 0; }
.bt-related-head { border-bottom: 2px solid var(--color-primary); padding-bottom: 10px; margin-bottom: 16px; }
.bt-related-title { font-size: 18px; margin: 0; }
.bt-rank-list { list-style: none; margin: 0; padding: 0; }
.bt-rank-item { display: flex; align-items: center; gap: 12px; padding: 10px 0; border-bottom: 1px dashed var(--color-border); }
.bt-rank-num { flex-shrink: 0; width: 22px; height: 22px; line-height: 22px; text-align: center; font-size: 12px; font-weight: 700; color: var(--color-text-light); background: var(--color-bg-gray); border-radius: var(--radius-sm); }
.bt-rank-num.bt-rank-top { background: var(--color-primary); color: #fff; }
.bt-rank-content { flex: 1; min-width: 0; }
.bt-rank-title { display: block; flex: 1; min-width: 0; font-size: 14px; color: var(--color-text-dark); white-space: nowrap; overflow: hidden; text-overflow: ellipsis; }
.bt-rank-title:hover { color: var(--color-primary-dark); text-decoration: none; }

/* ===== 分页 ===== */
.bt-pagination { text-align: center; margin-top: 26px; }
.pagination { display: inline-flex; list-style: none; padding: 0; margin: 0; gap: 6px; }
.pagination li a, .pagination li span { display: inline-block; min-width: 38px; height: 38px; line-height: 36px; padding: 0 14px; border: 1px solid var(--color-border); background: #fff; text-align: center; border-radius: var(--radius-sm); color: var(--color-text-dark); }
.pagination li a:hover { border-color: var(--color-primary); color: var(--color-primary-dark); text-decoration: none; }
.pagination .active a, .pagination .active span { background: var(--color-primary); color: #fff; border-color: var(--color-primary); font-weight: 600; }

/* ===== Article Summary ===== */
.article-summary {
    --as-primary: var(--color-primary);
    --as-bg: var(--color-primary-light);
    --as-border: var(--color-border);
    --as-text: var(--color-text-dark);
    --as-muted: var(--color-text-muted);
    margin: 24px auto;
    padding: 18px 22px;
    background: var(--as-bg);
    border-left: 4px solid var(--as-primary);
    border-radius: var(--radius-sm);
    max-width: 720px;
}
.article-summary-head { display: flex; align-items: center; gap: 8px; margin-bottom: 10px; }
.summary-deco { color: var(--as-primary); flex-shrink: 0; }
.article-summary-title { font-size: 15px; margin: 0; color: var(--as-text); font-weight: 600; }
.article-summary-text { color: var(--as-text); font-size: 14px; line-height: 1.8; margin: 0; }

/* ===== 回顶 ===== */
#floatbtn { position: fixed; right: 22px; bottom: 26px; z-index: 99; }
#back-to-top { display: flex; align-items: center; justify-content: center; width: 44px; height: 44px; background: var(--color-primary); color: #fff; border-radius: 50%; box-shadow: var(--shadow-md); transition: background 0.2s; }
#back-to-top:hover { background: var(--color-primary-dark); text-decoration: none; }
#back-to-top i { display: flex; align-items: center; justify-content: center; width: 100%; height: 100%; line-height: 1; }

/* ===== 卡片 padding 兜底 ===== */
.card > :where(:last-child):not(img):not(a) { padding: 15px; }

/* ===== 响应式 ===== */
@media (max-width: 991px) {
    .bt-grid { grid-template-columns: repeat(2, 1fr); }
    .bt-top-card { flex-direction: column; }
    .bt-top-cover { width: 100%; min-height: 200px; }
}
@media (max-width: 767px) {
    .bt-grid { grid-template-columns: 1fr; }
    .bt-cats { grid-template-columns: 1fr; }
    .bt-article { padding: 20px; }
    .bt-feed a { flex-direction: column; align-items: flex-start; gap: 6px; }
    .bt-feed-title { white-space: normal; }
}