/*
 * vip3mb00320 - 仿 PKU 高校门户·学术红主题
 * Primary: #8b0000  Bright: #c9302c  Gold: #d8ac5c  Cream: #f5f1ea
 */
* { box-sizing: border-box; }
html, body { margin: 0; padding: 0; overflow-x: hidden; }
body {
    font-family: "Microsoft YaHei","PingFang SC",Arial,sans-serif;
    font-size: 14px; color: #222; background: #fff; line-height: 1.8;
}
a { color: #222; text-decoration: none; transition: color .2s; }
a:hover { color: #8b0000; }
img { max-width: 100%; border: 0; vertical-align: middle; }
ul, ol { list-style: none; margin: 0; padding: 0; }
h1,h2,h3,h4,h5 { margin: 0; font-weight: normal; font-family: "Source Han Serif","Noto Serif SC","SimSun",serif; }
.clear { clear: both; }
.container { box-sizing: border-box; max-width: 1200px; width: auto; margin: 0 auto; padding: 0 20px; }

/* ==== Top bar (PKU 深红底白字) ==== */
.pku-topbar { background: #8b0000; color: #fff; height: 42px; line-height: 42px; font-size: 13px; }
.pku-topbar .container { display: flex; justify-content: space-between; align-items: center; }
.pku-topbar .left, .pku-topbar .right { display: flex; }
.pku-topbar a { color: #f3d7b5; padding: 0 18px; position: relative; letter-spacing: 1px; }
.pku-topbar .left a:not(:last-child)::after,
.pku-topbar .right a:not(:last-child)::after {
    content: ''; position: absolute; right: 0; top: 50%; transform: translateY(-50%);
    width: 1px; height: 12px; background: rgba(255,255,255,.25);
}
.pku-topbar a:hover { color: #fff; }

/* ==== Header (logo + 工具，导航独立成行) ==== */
.pku-header { background: #fff; border-bottom: 1px solid #eee; position: relative; }
.pku-header .container { display: flex; align-items: center; justify-content: space-between; height: 100px; gap: 20px; flex-wrap: nowrap; min-width: 0; }
.pku-header .logo { display: flex; align-items: center; flex: 1; min-width: 0; overflow: hidden; }
.pku-header .logo img { height: 64px; width: auto; flex-shrink: 0; }
.pku-header .logo .brand { margin-left: 14px; min-width: 0; overflow: hidden; }
.pku-header .logo .brand h1 { font-size: 26px; color: #8b0000; font-weight: bold; letter-spacing: 4px; font-family: "STKaiti","KaiTi","楷体","SimSun",serif; line-height: 1.1; white-space: nowrap; overflow: hidden; text-overflow: ellipsis; }
.pku-header .logo .brand p { margin: 6px 0 0; font-size: 11px; color: #8b0000; letter-spacing: 3px; font-family: "Times New Roman", serif; font-weight: 600; opacity: .85; white-space: nowrap; overflow: hidden; text-overflow: ellipsis; }

/* 主导航独立成行（深红底白字横条） */
.pku-navbar { background: #8b0000; border-top: 1px solid #6b0000; }
.pku-navbar .container { padding: 0 20px; }
.pku-navbar .pku-nav { display: flex; align-items: center; justify-content: center; flex-wrap: nowrap; gap: 0; white-space: nowrap; list-style: none; margin: 0; padding: 0; min-width: 0; overflow: hidden; }
.pku-navbar .pku-nav li { position: relative; flex: 0 0 auto; flex-shrink: 1; min-width: 0; text-align: center; }
.pku-navbar .pku-nav li a { display: block; padding: 0 22px; line-height: 50px; font-size: 16px; color: #fff; letter-spacing: 1px; font-family: "Microsoft YaHei", sans-serif; transition: background .2s, color .2s; white-space: nowrap; overflow: hidden; text-overflow: ellipsis; max-width: 160px; }
.pku-navbar .pku-nav li:hover > a, .pku-navbar .pku-nav li.active > a { background: #6b0000; color: #f3d7b5; }
.pku-navbar .pku-nav li::after { content: ''; position: absolute; left: 50%; bottom: 0; width: 0; height: 3px; background: #d8ac5c; transition: .25s; transform: translateX(-50%); }
.pku-navbar .pku-nav li:hover::after, .pku-navbar .pku-nav li.active::after { width: 60%; }

/* 工具按钮 */
.pku-tools { display: flex; align-items: center; gap: 10px; flex-shrink: 0; }
.pku-tools .tool-btn { width: 38px; height: 38px; border-radius: 50%; background: #fff; border: 1px solid #ddd; display: inline-flex; align-items: center; justify-content: center; color: #444; font-size: 13px; font-weight: 600; transition: .2s; }
.pku-tools .tool-btn:hover { background: #8b0000; color: #fff !important; border-color: #8b0000; }
.pku-tools .en-btn { letter-spacing: 1px }

/* 兼容旧 .pku-nav 顶级（footer 或外部用） */
.pku-nav { background: transparent; }

/* ==== Search box (浮层) ==== */
.pku-search {
    display: none; position: fixed; left: 50%; top: 80px; transform: translateX(-50%);
    background: #fff; box-shadow: 0 8px 30px rgba(0,0,0,.18); padding: 18px; z-index: 100;
    width: 480px; max-width: 92%;
}
.pku-search.on { display: block; }
.pku-search form { display: flex; border: 2px solid #8b0000; }
.pku-search input[type=text] { border: 0; outline: 0; padding: 10px 14px; flex: 1; font-size: 14px; }
.pku-search button { border: 0; background: #8b0000; color: #fff; padding: 0 24px; font-size: 14px; cursor: pointer; }

/* ==== Slide / Banner ==== */
.pku-slide { width: 100%; background: #f5f1ea; position: relative; overflow: hidden; }
.pku-slide img { width: 100%; display: block; }

/* ==== Common section ==== */
.section { padding: 50px 0; background: #fff; }
.section.cream { background: #f5f1ea; }
.section-title { display: flex; align-items: baseline; justify-content: space-between; border-bottom: 1px solid #e5d7b9; padding-bottom: 12px; margin-bottom: 24px; }
.section-title h2 { font-size: 26px; color: #8b0000; position: relative; padding-left: 18px; letter-spacing: 2px; }
.section-title h2::before {
    content: ''; position: absolute; left: 0; top: 6px; bottom: 6px; width: 5px; background: #8b0000;
}
.section-title h2 em { color: #d8ac5c; font-style: normal; font-size: 14px; margin-left: 10px; letter-spacing: 3px; font-family: "Times New Roman", serif; }
.section-title .more { font-size: 13px; color: #8b6a3b; }
.section-title .more:hover { color: #8b0000; }

/* ==== News: 北大·要闻 卡片网格（仿源站） ==== */
.pku-news-title { text-align: center; margin: 0 0 36px; position: relative; }
.pku-news-title h2 { font-size: 32px; color: #1a1a1a; letter-spacing: 6px; font-weight: 300; font-family: "Source Han Serif","Noto Serif SC","SimSun",serif; }
.pku-news-title h2 .dot { color: #8b0000; margin: 0 6px; font-weight: 600; }
.pku-news-title .more { position: absolute; right: 0; top: 50%; transform: translateY(-50%); font-size: 13px; color: #8b6a3b; letter-spacing: 1px; }
.pku-news-title .more:hover { color: #8b0000; }

.pku-news { display: grid; grid-template-columns: minmax(0, 1.45fr) minmax(0, 1fr); gap: 22px; margin-bottom: 22px; }
.pku-news .card { background: #fff; box-shadow: 0 2px 10px rgba(0,0,0,.06); transition: transform .25s, box-shadow .25s; position: relative; overflow: hidden; display: block; }
.pku-news .card::after { content: ''; position: absolute; left: 0; bottom: 0; width: 60px; height: 3px; background: #8b0000; transition: width .3s; }
.pku-news .card:hover { transform: translateY(-3px); box-shadow: 0 8px 22px rgba(139,0,0,.15); }
.pku-news .card:hover::after { width: 100%; }

/* 大头条卡 */
.pku-news .card.big { display: flex; flex-direction: column; min-height: 460px; background: #8b0000; color: #fff; }
.pku-news .card.big .pic { flex: 1; overflow: hidden; background: #6b0000; }
.pku-news .card.big .pic img { width: 100%; height: 100%; object-fit: cover; opacity: .9; transition: transform .5s; }
.pku-news .card.big:hover .pic img { transform: scale(1.05); }
.pku-news .card.big .cap { padding: 22px 28px; background: #fff; }
.pku-news .card.big .cap h3 { font-size: 18px; color: #1a1a1a; line-height: 1.5; font-weight: 500; font-family: "Microsoft YaHei", sans-serif; }
.pku-news .card.big::after { background: transparent; }

/* 右侧 2x2 文字卡 */
.pku-news .grid4 { display: grid; grid-template-columns: 1fr 1fr; gap: 18px; }
.pku-news .grid4 .card.text { padding: 26px 24px; min-height: 220px; display: flex; align-items: center; }
.pku-news .grid4 .card.text h4 { font-size: 15px; color: #1a1a1a; line-height: 1.7; font-weight: 500; font-family: "Microsoft YaHei", sans-serif; display: -webkit-box; -webkit-line-clamp: 5; -webkit-box-orient: vertical; overflow: hidden; }
.pku-news .grid4 .card.text:hover h4 { color: #8b0000; }

/* 下方一行：左 2 文字 + 右 1 大图卡 */
.pku-news-row { display: grid; grid-template-columns: minmax(0, 1fr) minmax(0, 1fr) minmax(0, 1.5fr); gap: 22px; }
.pku-news-row .card { background: #fff; box-shadow: 0 2px 10px rgba(0,0,0,.06); transition: .25s; position: relative; overflow: hidden; display: block; }
.pku-news-row .card::after { content: ''; position: absolute; left: 0; bottom: 0; width: 60px; height: 3px; background: #8b0000; transition: width .3s; }
.pku-news-row .card:hover { transform: translateY(-3px); box-shadow: 0 8px 22px rgba(139,0,0,.15); }
.pku-news-row .card:hover::after { width: 100%; }
.pku-news-row .card.text { padding: 28px 26px; min-height: 240px; display: flex; align-items: center; }
.pku-news-row .card.text h4 { font-size: 15px; color: #1a1a1a; line-height: 1.7; font-weight: 500; display: -webkit-box; -webkit-line-clamp: 5; -webkit-box-orient: vertical; overflow: hidden; }
.pku-news-row .card.text:hover h4 { color: #8b0000; }
.pku-news-row .card.big-img { background: #1d3a8b; color: #fff; min-height: 240px; }
.pku-news-row .card.big-img img { width: 100%; height: 100%; object-fit: cover; opacity: .55; position: absolute; inset: 0; }
.pku-news-row .card.big-img .ttl { position: absolute; left: 24px; right: 24px; bottom: 22px; font-size: 16px; line-height: 1.5; color: #fff; font-weight: 500; z-index: 2; text-shadow: 0 2px 8px rgba(0,0,0,.4); }
.pku-news-row .card.big-img::after { background: transparent; }

/* ==== Four-column news wall ==== */
.pku-4col { display: flex; gap: 26px; }
.pku-4col .col { flex: 1; background: #fff; border-top: 3px solid #8b0000; padding: 18px 20px; }
.pku-4col .col .col-head { display: flex; justify-content: space-between; align-items: baseline; border-bottom: 1px solid #e5d7b9; padding-bottom: 10px; margin-bottom: 10px; }
.pku-4col .col .col-head h3 { font-size: 18px; color: #8b0000; letter-spacing: 2px; }
.pku-4col .col .col-head a { font-size: 12px; color: #8b6a3b; }
.pku-4col .col ul li { padding: 8px 0 8px 14px; position: relative; font-size: 14px; border-bottom: 1px dashed #ebddc0; }
.pku-4col .col ul li:last-child { border-bottom: 0; }
.pku-4col .col ul li::before { content: ''; position: absolute; left: 0; top: 50%; width: 4px; height: 4px; background: #8b0000; border-radius: 50%; transform: translateY(-50%); }
.pku-4col .col ul li a { color: #333; display: block; white-space: nowrap; overflow: hidden; text-overflow: ellipsis; }
.pku-4col .col ul li a:hover { color: #8b0000; }

/* ==== Topics wall ==== */
.pku-topics { display: flex; gap: 26px; }
.pku-topics .card { flex: 1; position: relative; overflow: hidden; height: 220px; background: #e5d7b9; }
.pku-topics .card img { width: 100%; height: 100%; object-fit: cover; transition: transform .5s; }
.pku-topics .card:hover img { transform: scale(1.06); }
.pku-topics .card .mask { position: absolute; left: 0; right: 0; bottom: 0; padding: 16px 20px; background: linear-gradient(180deg,transparent,rgba(148,7,10,.92)); color: #fff; }
.pku-topics .card .mask h3 { font-size: 18px; letter-spacing: 2px; }
.pku-topics .card .mask p { margin-top: 4px; font-size: 12px; color: #f3e6cc; }

/* ==== Quick entries (6格) ==== */
.pku-quick { display: flex; gap: 0; border: 1px solid #e5d7b9; }
.pku-quick a {
    flex: 1; text-align: center; padding: 22px 10px; border-right: 1px solid #e5d7b9;
    font-size: 15px; color: #333; background: #fff; transition: all .25s;
}
.pku-quick a:last-child { border-right: 0; }
.pku-quick a:hover { background: #8b0000; color: #fff; }
.pku-quick a .ico { display: block; font-size: 28px; color: #8b0000; margin-bottom: 8px; font-family: "Source Han Serif",serif; }
.pku-quick a:hover .ico { color: #d8ac5c; }

/* ==== Page banner ==== */
.page-banner { height: 220px; background: #8b0000 url('../images/about_bg.jpg') center/cover no-repeat; position: relative; }
.page-banner::after { content: ''; position: absolute; inset: 0; background: rgba(122,6,8,.65); }
.page-banner .inner { position: relative; z-index: 1; width: 1200px; margin: 0 auto; color: #fff; padding-top: 70px; }
.page-banner h2 { font-size: 34px; letter-spacing: 6px; font-weight: bold; }
.page-banner .en { margin-top: 8px; font-size: 14px; color: #f3d7a1; letter-spacing: 4px; font-family: "Times New Roman",serif; text-transform: uppercase; }

.breadcrumb { background: #f5f1ea; border-bottom: 1px solid #e5d7b9; }
.breadcrumb .container { padding: 14px 0; font-size: 13px; color: #666; }
.breadcrumb a { color: #666; }
.breadcrumb a:hover { color: #8b0000; }

.main-wrap { padding: 40px 0 60px; }
.main-wrap .container { display: flex; gap: 30px; align-items: flex-start; }
.main-wrap .content { flex: 1; background: #fff; border: 1px solid #ebddc0; padding: 30px 36px; min-height: 480px; }
.main-wrap .sidebar { width: 280px; }

/* list items */
.arc-list li {
    padding: 18px 6px; border-bottom: 1px dashed #e5d7b9; display: flex; align-items: center;
}
.arc-list li .date { width: 80px; color: #8b0000; font-family: "Times New Roman",serif; text-align: center; border-right: 1px solid #e5d7b9; margin-right: 20px; line-height: 1.3; }
.arc-list li .date .d { display: block; font-size: 24px; font-weight: bold; }
.arc-list li .date .m { display: block; font-size: 12px; color: #8b6a3b; }
.arc-list li .txt { flex: 1; }
.arc-list li .txt h3 { font-size: 17px; font-family: "Microsoft YaHei",sans-serif; margin-bottom: 6px; }
.arc-list li .txt p { color: #777; font-size: 13px; line-height: 1.8; }

/* pagination */
.pagelist { display: flex; flex-wrap: wrap; justify-content: center; margin-top: 30px; padding-top: 20px; border-top: 1px solid #ebddc0; }
.pagelist li { margin: 4px; }
.pagelist li a, .pagelist li span {
    display: inline-block; padding: 6px 14px; border: 1px solid #e5d7b9; background: #fff; color: #555;
    font-size: 13px;
}
.pagelist li.thisclass span, .pagelist li a:hover { background: #8b0000; color: #fff; border-color: #8b0000; }

/* article detail */
.arc-detail .title { font-size: 28px; color: #222; text-align: center; letter-spacing: 2px; line-height: 1.5; }
.arc-detail .meta { text-align: center; color: #8b6a3b; font-size: 13px; padding: 14px 0; border-bottom: 1px solid #ebddc0; margin-bottom: 24px; font-family: "Times New Roman","SimSun",serif; }
.arc-detail .meta span { margin: 0 10px; }
.arc-detail .body { font-size: 16px; color: #333; line-height: 2; font-family: "Source Han Serif","SimSun",serif; }
.arc-detail .body p { margin: 0 0 16px; text-indent: 2em; }
.arc-detail .body img { max-width: 100%; height: auto; margin: 10px 0; display: block; }
.arc-detail .tags { margin-top: 30px; padding-top: 20px; border-top: 1px dashed #ebddc0; }
.arc-detail .tags a { display: inline-block; padding: 4px 14px; margin: 0 6px 6px 0; background: #f5f1ea; color: #8b0000; font-size: 12px; border: 1px solid #e5d7b9; }
.arc-detail .tags a:hover { background: #8b0000; color: #fff; border-color: #8b0000; }
.arc-detail .prev-next { margin-top: 24px; padding: 16px 20px; background: #f5f1ea; border-left: 4px solid #8b0000; font-size: 14px; line-height: 2; }
.arc-detail .prev-next a { color: #8b0000; }

/* sidebar panel */
.panel { background: #fff; border: 1px solid #ebddc0; margin-bottom: 20px; }
.panel .panel-head { padding: 12px 20px; background: #8b0000; color: #fff; font-size: 16px; letter-spacing: 2px; font-family: "Source Han Serif","SimSun",serif; border-bottom: 2px solid #d8ac5c; }
.panel .panel-head em { color: #f3d7a1; font-style: normal; font-size: 12px; margin-left: 8px; letter-spacing: 2px; }
.panel .panel-body { padding: 12px 18px; }
.panel .panel-body ul li { padding: 8px 0 8px 14px; position: relative; font-size: 13px; border-bottom: 1px dashed #ebddc0; }
.panel .panel-body ul li::before { content: ''; position: absolute; left: 0; top: 50%; width: 4px; height: 4px; background: #8b0000; transform: translateY(-50%); }
.panel .panel-body ul li:last-child { border-bottom: 0; }

/* topic page */
.tag-cloud { display: flex; flex-wrap: wrap; gap: 10px; padding: 10px 0 20px; }
.tag-cloud li a { display: inline-block; padding: 8px 18px; background: #f5f1ea; color: #8b0000; border: 1px solid #e5d7b9; font-size: 14px; }
.tag-cloud li a:hover { background: #8b0000; color: #fff; border-color: #8b0000; }

/* ==== Footer ==== */
.flinks { background: #7a0608; color: #f3d7a1; padding: 20px 0; font-size: 14px; border-top: 3px solid #d8ac5c; }
.flinks .container { line-height: 32px; }
.flinks .label { display: inline-block; color: #ffd28a; letter-spacing: 2px; font-weight: 700; font-size: 15px; margin-right: 24px; vertical-align: middle; }
.flinks ul { display: inline; padding: 0; margin: 0; list-style: none; }
.flinks ul li { display: inline-block; vertical-align: middle; margin: 0; padding: 0; }
.flinks ul li a { display: inline-block; padding: 0 20px; color: #f3d7a1; font-size: 14px; line-height: 1.2; border-right: 1px solid rgba(255,255,255,.25); }
.flinks ul li:last-child a { border-right: 0; }
.flinks ul li a:hover { color: #fff; }

.site-footer { background: #5e0405; color: #cbb489; padding: 36px 0 24px; font-size: 13px; line-height: 1.9; }
.site-footer .container { display: flex; justify-content: space-between; align-items: center; }
.site-footer .left p { margin: 0 0 4px; }
.site-footer .left p strong { color: #f3d7a1; font-size: 16px; letter-spacing: 2px; }
.site-footer a { color: #cbb489; }
.site-footer a:hover { color: #fff; }
.site-footer .beian img { height: 18px; vertical-align: middle; margin-right: 4px; }
.site-footer .right { text-align: right; }

/* ============ PKU 5 类特色板块（北大红+金） ============ */
/* 1. 北大学者 */
.pku-people { display: grid; grid-template-columns: 1.2fr 1fr; gap: 26px; }
.pku-people .star { position: relative; height: 420px; overflow: hidden; background: #e5d7b9; }
.pku-people .star img { width: 100%; height: 100%; object-fit: cover; transition: transform .5s; }
.pku-people .star:hover img { transform: scale(1.04); }
.pku-people .star .info { position: absolute; left: 0; right: 0; bottom: 0; padding: 22px 24px; background: linear-gradient(180deg,transparent,rgba(94,4,5,.92)); color: #fff; }
.pku-people .star .info h3 { font-size: 22px; letter-spacing: 3px; margin-bottom: 6px; font-family: "Source Han Serif SC","STSong",serif; }
.pku-people .star .info .role { font-size: 13px; color: #f3d7a1; letter-spacing: 2px; }
.pku-people .star .info p { margin-top: 10px; font-size: 13px; line-height: 1.7; color: #f5e6c8; }
.pku-people .list { display: flex; flex-direction: column; gap: 14px; }
.pku-people .list .item { flex: 1; display: flex; align-items: center; padding: 18px 20px; background: #fff; border: 1px solid #e5d7b9; border-left: 3px solid #8b0000; transition: all .25s; }
.pku-people .list .item:hover { background: #f5f1ea; border-left-color: #d8ac5c; transform: translateX(4px); }
.pku-people .list .item .num { font-family: "Times New Roman",serif; font-size: 36px; color: #d8ac5c; margin-right: 18px; font-style: italic; line-height: 1; }
.pku-people .list .item h4 { font-size: 16px; color: #222; margin-bottom: 4px; }
.pku-people .list .item p { font-size: 12px; color: #8b6a3b; letter-spacing: 1px; }

/* 2. 学术 + 媒体 双栏 */
.pku-twocol { display: grid; grid-template-columns: 1fr 1fr; gap: 30px; }
.pku-twocol .col { background: #fff; border: 1px solid #ebddc0; padding: 22px 24px; }
.pku-twocol .col .col-head { display: flex; justify-content: space-between; align-items: baseline; padding-bottom: 12px; border-bottom: 2px solid #8b0000; margin-bottom: 14px; }
.pku-twocol .col .col-head h3 { font-size: 20px; color: #8b0000; letter-spacing: 2px; }
.pku-twocol .col .col-head h3 em { font-style: normal; color: #d8ac5c; font-size: 12px; margin-left: 8px; letter-spacing: 2px; font-family: "Times New Roman",serif; }
.pku-twocol .col .col-head a { font-size: 12px; color: #8b6a3b; }
.pku-twocol .col .top { display: flex; gap: 14px; padding-bottom: 12px; border-bottom: 1px dashed #e5d7b9; margin-bottom: 10px; }
.pku-twocol .col .top .pic { width: 150px; height: 100px; flex-shrink: 0; overflow: hidden; background: #e5d7b9; }
.pku-twocol .col .top .pic img { width: 100%; height: 100%; object-fit: cover; }
.pku-twocol .col .top .txt h4 { font-size: 16px; line-height: 1.5; margin-bottom: 6px; }
.pku-twocol .col .top .txt p { font-size: 12px; color: #777; line-height: 1.7; }
.pku-twocol .col ul li { padding: 7px 0 7px 14px; position: relative; font-size: 14px; border-bottom: 1px dashed #ebddc0; }
.pku-twocol .col ul li:last-child { border-bottom: 0; }
.pku-twocol .col ul li::before { content: ''; position: absolute; left: 0; top: 50%; width: 4px; height: 4px; background: #8b0000; transform: translateY(-50%); }
.pku-twocol .col ul li a { color: #333; display: block; white-space: nowrap; overflow: hidden; text-overflow: ellipsis; }

/* 3. 数字北大 */
.pku-stats { padding: 60px 0; background: linear-gradient(135deg,#8b0000 0%,#5e0405 100%); color: #fff; position: relative; }
.pku-stats::before { content: ''; position: absolute; inset: 0; background: url('../images/about_bg.jpg') center/cover no-repeat; opacity: .08; pointer-events: none; }
.pku-stats .container { position: relative; z-index: 1; }
.pku-stats .stats-head { text-align: center; margin-bottom: 40px; }
.pku-stats .stats-head h2 { font-size: 30px; color: #fff; letter-spacing: 4px; font-family: "Source Han Serif SC","STSong",serif; }
.pku-stats .stats-head em { display: block; margin-top: 8px; font-style: normal; font-size: 13px; color: #f3d7a1; letter-spacing: 4px; font-family: "Times New Roman",serif; }
.pku-stats .grid { display: grid; grid-template-columns: repeat(6,1fr); gap: 20px; }
.pku-stats .grid .stat { text-align: center; padding: 22px 10px; border: 1px solid rgba(243,215,161,.25); }
.pku-stats .grid .stat .n { font-size: 42px; color: #f3d7a1; font-family: "Times New Roman",serif; font-weight: bold; line-height: 1; }
.pku-stats .grid .stat .n sup { font-size: 18px; vertical-align: super; }
.pku-stats .grid .stat .lbl { margin-top: 10px; font-size: 13px; color: #f5e6c8; letter-spacing: 2px; }

/* 4. 北大影音 + 燕园视野 */
.pku-pic-video { display: grid; grid-template-columns: 1.4fr 1fr; gap: 26px; }
.pku-pic-video .big { position: relative; height: 380px; overflow: hidden; background: #e5d7b9; }
.pku-pic-video .big img { width: 100%; height: 100%; object-fit: cover; transition: transform .5s; }
.pku-pic-video .big:hover img { transform: scale(1.05); }
.pku-pic-video .big .play { position: absolute; left: 50%; top: 50%; width: 64px; height: 64px; margin: -32px 0 0 -32px; background: rgba(148,7,10,.85); color: #f3d7a1; border-radius: 50%; display: flex; align-items: center; justify-content: center; font-size: 26px; transition: all .3s; }
.pku-pic-video .big:hover .play { background: #8b0000; transform: scale(1.1); }
.pku-pic-video .big .ttl { position: absolute; left: 0; right: 0; bottom: 0; padding: 16px 20px; background: linear-gradient(180deg,transparent,rgba(0,0,0,.7)); color: #fff; font-size: 17px; letter-spacing: 2px; }
.pku-pic-video .grid4 { display: grid; grid-template-columns: 1fr 1fr; grid-template-rows: 1fr 1fr; gap: 12px; }
.pku-pic-video .grid4 .it { position: relative; overflow: hidden; background: #e5d7b9; height: 184px; border: 2px solid transparent; transition: border-color .25s; }
.pku-pic-video .grid4 .it:hover { border-color: #d8ac5c; }
.pku-pic-video .grid4 .it img { width: 100%; height: 100%; object-fit: cover; }
.pku-pic-video .grid4 .it .ttl { position: absolute; left: 0; right: 0; bottom: 0; padding: 8px 12px; background: linear-gradient(180deg,transparent,rgba(94,4,5,.88)); color: #fff; font-size: 13px; letter-spacing: 1px; }

/* 5. 院系机构 */
.pku-colleges { display: grid; grid-template-columns: repeat(6,1fr); gap: 12px; }
.pku-colleges a { display: block; text-align: center; padding: 22px 8px; background: #fff; border: 1px solid #e5d7b9; font-size: 14px; color: #333; transition: all .25s; letter-spacing: 1px; }
.pku-colleges a:hover { background: #8b0000; color: #fff; border-color: #8b0000; transform: translateY(-3px); box-shadow: 0 6px 14px rgba(148,7,10,.25); }
.pku-colleges a span { display: block; font-family: "Times New Roman",serif; font-size: 11px; color: #d8ac5c; margin-top: 4px; letter-spacing: 1px; }

/* ============ 响应式自匹配 ============ */
@media (max-width: 1200px) {
    .container { width: 100%; padding: 0 15px; box-sizing: border-box; }
    .pku-stats .grid { grid-template-columns: repeat(3,1fr); }
    .pku-colleges { grid-template-columns: repeat(4,1fr); }
}
@media (max-width: 768px) {
    body { font-size: 14px; }
    .pku-topbar, .pku-search { display: none !important; }
    .pku-header { background-image: none; border-bottom-width: 1px; }
    .pku-header .container { height: auto; padding: 12px 0; flex-wrap: wrap; }
    .pku-header .logo { width: 100%; }
    .pku-header .logo img { height: 46px; }
    .pku-header .logo .brand { padding-left: 12px; margin-left: 12px; }
    .pku-header .logo .brand h1 { font-size: 18px; letter-spacing: 2px; }
    .pku-header .logo .brand p { font-size: 11px; letter-spacing: 1px; }
    .pku-header .motto { display: none; }
    /* 主导航独立行：手机端横向滚动避免文字溢出 */
    .pku-navbar { overflow-x: auto; -webkit-overflow-scrolling: touch; }
    .pku-navbar::-webkit-scrollbar { display: none; }
    .pku-navbar .pku-nav { justify-content: flex-start; overflow: visible; }
    .pku-navbar .pku-nav li a { padding: 0 14px; line-height: 44px; font-size: 14px; max-width: none; }
    .pku-nav { height: auto; }
    .pku-slide, .swiper-container, .swiper-slide { height: 220px !important; }
    .pku-slide img, .swiper-slide img { height: 220px !important; object-fit: cover; }
    .pku-news { flex-direction: column; }
    .pku-news .left, .pku-news .right { width: 100% !important; }
    .pku-3col, .pku-2col { grid-template-columns: 1fr !important; display: block; }
    .pku-3col .col, .pku-2col .col { margin-bottom: 16px; }
    .pku-topics { flex-wrap: wrap; }
    .pku-topics .card { width: calc(50% - 6px); margin-bottom: 10px; }
    .pku-quick { flex-wrap: wrap; }
    .pku-quick a { width: 33.33%; box-sizing: border-box; padding: 14px 4px; font-size: 12px; }
    .page-banner { height: 140px !important; }
    .page-banner .inner h2 { font-size: 22px; }
    .breadcrumb .container { padding: 8px 15px; font-size: 12px; }
    .main-wrap .container { flex-direction: column; padding: 16px 15px; }
    .content, .arc-detail, .arc-list { width: 100% !important; }
    .arc-detail .title { font-size: 20px; line-height: 1.4; }
    .arc-detail .meta span { display: inline-block; margin-right: 8px; font-size: 12px; }
    .right-bar, .sidebar { width: 100% !important; margin: 16px 0 0 !important; }
    .flinks ul { flex-wrap: wrap; }
    .site-footer { padding: 20px 0; }
    .site-footer .container { flex-direction: column; text-align: center; gap: 8px; }
    .site-footer .right { text-align: center; }
    img { max-width: 100%; height: auto; }
    table { max-width: 100%; }
}

/* 防溢出补丁: grid 子项 min-width:0 让 ellipsis 生效 */
.pku-4col .col,.pku-twocol .col,.pku-news .col,.pku-topics .col,.pku-pic-video .col,.pku-stats .stat,.pku-colleges a{min-width:0}
.pku-4col .col,.pku-twocol .col,.pku-news .col,.pku-topics .col{overflow:hidden}
.pku-4col ul,.pku-twocol ul,.pku-news ul,.pku-topics ul{min-width:0}
.pku-4col li a,.pku-twocol li a,.pku-news li a,.pku-topics li a{display:block;overflow:hidden;text-overflow:ellipsis;white-space:nowrap;max-width:100%}
.pku-twocol .col .top .txt h4{word-break:break-all}