*,*::before,*::after{box-sizing:border-box;margin:0;padding:0}
html{scroll-behavior:smooth}
a{color:inherit;text-decoration:none}
img{max-width:100%;display:block}
button,input,textarea,select{font:inherit}
.container{max-width:1280px;margin:0 auto;padding:0 24px}
.page{padding:20px 0 36px}
.page__title{font-size:clamp(1.5rem,3vw,2rem);margin-bottom:8px}
.page__sub{color:var(--muted);margin-bottom:28px}
.page--narrow{max-width:480px;margin-left:auto;margin-right:auto}
.breadcrumb{margin-bottom:20px;font-size:.85rem;color:var(--muted)}
.section__title{font-size:1.2rem;margin:32px 0 20px}
.empty-state{color:var(--muted);padding:40px;text-align:center}

/* Header */
.header{position:sticky;top:0;z-index:100;background:var(--surface);border-bottom:1px solid var(--border);transition:box-shadow .3s}
.header--scrolled{box-shadow:var(--shadow)}
.header__inner{max-width:1280px;margin:0 auto;padding:0 24px;height:60px;display:flex;align-items:center;gap:16px}
.logo{font-size:1.05rem;flex-shrink:0}
.nav{display:flex;gap:2px;margin-left:auto;flex-wrap:wrap}
.nav a{font-size:.76rem;padding:8px 10px;border-radius:var(--radius);color:var(--muted);white-space:nowrap}
.nav a.is-active,.nav a:hover{color:var(--primary);background:rgba(0,0,0,.04)}
.header__actions{display:flex;align-items:center;gap:10px;margin-left:8px;flex-shrink:0}
.header__user{font-size:.82rem;color:var(--muted)}
.msg-badge{display:inline-grid;place-items:center;min-width:16px;height:16px;padding:0 4px;border-radius:999px;background:var(--primary);color:#fff;font-size:.65rem}
.nav-toggle{display:none;background:none;border:none;cursor:pointer}
.nav-toggle span{display:block;width:20px;height:2px;background:var(--text);margin:4px 0}

/* Hero */
.hero{position:relative;min-height:240px;display:flex;align-items:center;overflow:hidden}
.hero--compact{min-height:160px}
.hero__bg{position:absolute;inset:0}
.hero__bg img{width:100%;height:100%;object-fit:cover}
.hero__overlay{position:absolute;inset:0}
.hero__content{position:relative;z-index:2;padding:24px 20px;max-width:1280px;margin:0 auto;width:100%}
.hero__tag{font-size:.72rem;letter-spacing:.15em;color:var(--muted);margin-bottom:8px}
.hero__content h1{font-size:clamp(1.8rem,4vw,2.8rem);margin-bottom:8px}
.hero__desc{max-width:480px;color:var(--muted);line-height:1.7}

/* Stats bar */
.stats-bar{display:grid;grid-template-columns:repeat(5,1fr);gap:1px;background:var(--border);border:1px solid var(--border);border-radius:var(--radius);overflow:hidden;margin-bottom:28px}
.stat-item{background:var(--surface);padding:20px 16px;text-align:center}
.stat-item__num{display:block;font-size:clamp(1.1rem,2.5vw,1.6rem);font-weight:700;color:var(--primary);margin-bottom:4px}
.stat-item__label{font-size:.72rem;color:var(--muted);letter-spacing:.05em}

/* Category grid */
.category-grid{display:grid;grid-template-columns:repeat(6,1fr);gap:12px;margin-bottom:28px}
.category-card{display:flex;flex-direction:column;align-items:center;gap:6px;padding:16px 8px;background:var(--surface);border:1px solid var(--border);border-radius:var(--radius);text-align:center;transition:transform .2s,box-shadow .2s,border-color .2s}
.category-card:hover{transform:translateY(-2px);box-shadow:var(--shadow);border-color:var(--primary)}
.category-card__icon{font-size:1.6rem;line-height:1}
.category-card__name{font-size:.78rem;font-weight:600;line-height:1.3}
.category-card__count{font-size:.65rem;color:var(--muted)}

/* Announcement bar */
.announcement-bar{background:var(--surface);border:1px solid var(--border);border-radius:var(--radius);padding:16px 20px;margin-bottom:24px;overflow:hidden}
.announcement-bar__label{font-size:.68rem;font-weight:700;color:var(--primary);letter-spacing:.1em;margin-bottom:12px;display:flex;align-items:center;gap:6px}
.announcement-bar__label::before{content:'';width:6px;height:6px;border-radius:50%;background:var(--primary);animation:pulse 2s infinite}
@keyframes pulse{0%,100%{opacity:1}50%{opacity:.4}}
.announcement-item{display:flex;align-items:center;gap:12px;padding:10px 0;border-bottom:1px solid var(--border);font-size:.82rem;flex-wrap:wrap}
.announcement-item:last-child{border-bottom:none;padding-bottom:0}
.announcement-item__badge{font-size:.62rem;padding:2px 8px;border-radius:999px;background:var(--primary);color:#fff;flex-shrink:0}
.announcement-item strong{flex-shrink:0;max-width:200px;white-space:nowrap;overflow:hidden;text-overflow:ellipsis}
.announcement-item__text{color:var(--muted);flex:1;min-width:0;white-space:nowrap;overflow:hidden;text-overflow:ellipsis}
.announcement-item time{font-size:.72rem;color:var(--muted);flex-shrink:0}

/* Feed tabs */
.feed-tabs{display:flex;gap:6px;flex-wrap:wrap;margin-bottom:20px;padding-bottom:12px;border-bottom:1px solid var(--border)}
.feed-tab{padding:6px 14px;border:1px solid var(--border);border-radius:999px;background:var(--surface);color:var(--muted);font-size:.78rem;cursor:pointer;transition:all .2s}
.feed-tab.is-active,.feed-tab:hover{background:var(--primary);color:#fff;border-color:var(--primary)}

/* Feed & posts */
.feed{display:flex;flex-direction:column;gap:12px}
.post-card{background:var(--surface);padding:20px;transition:transform .2s,box-shadow .2s;border:1px solid var(--border);border-radius:var(--radius);position:relative}
.post-card:hover{transform:translateY(-2px)}
.post-card--pinned{border-color:var(--primary);background:rgba(0,0,0,.01)}
.post-card__pinned{position:absolute;top:12px;right:12px;font-size:.62rem;padding:2px 8px;border-radius:999px;background:var(--primary);color:#fff}
.post-card__head{display:flex;gap:12px;align-items:center;margin-bottom:12px}
.post-card__avatar{width:44px;height:44px;border-radius:50%;object-fit:cover}
.post-card__meta{flex:1}
.post-card__meta strong{display:block;font-size:.9rem}
.post-card__meta span{font-size:.75rem;color:var(--muted)}
.post-card__badges{display:flex;gap:8px;flex-wrap:wrap;margin-bottom:8px;align-items:center}
.post-card__category{font-size:.68rem;padding:2px 10px;border-radius:999px;background:var(--primary);color:#fff;font-weight:600}
.post-card__tag{display:inline-block;padding:2px 10px;font-size:.68rem;border-radius:999px;background:rgba(0,0,0,.06);color:var(--primary)}
.post-card__text{line-height:1.75;margin-bottom:12px;font-size:.92rem}
.post-card__img{border-radius:var(--radius);margin-bottom:12px;max-height:320px;object-fit:cover;width:100%}
.post-card__foot{display:flex;gap:20px;font-size:.8rem;color:var(--muted)}
.post-card__foot button{background:none;border:none;cursor:pointer;color:inherit;display:flex;align-items:center;gap:4px}
.post-card__foot button.is-liked{color:var(--primary)}

/* Category page */
.category-page{margin-bottom:32px}
.category-header{display:flex;gap:20px;align-items:flex-start;padding:28px;background:var(--surface);border:1px solid var(--border);border-radius:var(--radius);margin-bottom:28px}
.category-header__icon{font-size:3rem;line-height:1;flex-shrink:0}
.category-header h1{font-size:1.6rem;margin-bottom:8px}
.category-header p{color:var(--muted);line-height:1.6;margin-bottom:12px}
.category-header__meta{display:flex;gap:16px;font-size:.82rem;color:var(--muted);flex-wrap:wrap}
.category-header__meta em{font-style:normal;padding:2px 8px;background:rgba(0,0,0,.04);border-radius:999px;font-size:.75rem}

.categories-full-grid{display:grid;grid-template-columns:repeat(auto-fill,minmax(260px,1fr));gap:16px}
.category-full-card{display:flex;gap:16px;padding:20px;background:var(--surface);border:1px solid var(--border);border-radius:var(--radius);transition:transform .2s,box-shadow .2s}
.category-full-card:hover{transform:translateY(-2px);box-shadow:var(--shadow)}
.category-full-card__icon{font-size:2rem;flex-shrink:0}
.category-full-card h3{font-size:.95rem;margin-bottom:4px}
.category-full-card p{font-size:.78rem;color:var(--muted);line-height:1.5;margin-bottom:8px}
.category-full-card__meta{font-size:.72rem;color:var(--primary)}

/* Wiki */
.wiki-list{display:grid;grid-template-columns:repeat(auto-fill,minmax(320px,1fr));gap:16px}
.wiki-item{background:var(--surface);border:1px solid var(--border);border-radius:var(--radius);padding:24px;transition:transform .2s,box-shadow .2s}
.wiki-item:hover{transform:translateY(-2px);box-shadow:var(--shadow)}
.wiki-item__cat{font-size:.68rem;padding:2px 10px;border-radius:999px;background:rgba(0,0,0,.06);color:var(--primary);display:inline-block;margin-bottom:10px}
.wiki-item h3{font-size:1rem;margin-bottom:8px}
.wiki-item p{font-size:.85rem;color:var(--muted);line-height:1.6;margin-bottom:12px}
.wiki-item footer{font-size:.72rem;color:var(--muted)}

/* Expert grid */
.expert-grid{display:grid;grid-template-columns:repeat(auto-fill,minmax(220px,1fr));gap:12px}
.expert-card{display:flex;gap:12px;align-items:center;padding:14px;background:var(--surface);border:1px solid var(--border);border-radius:var(--radius)}
.expert-card__avatar{width:48px;height:48px;border-radius:50%;object-fit:cover;flex-shrink:0}
.expert-card__info{display:flex;flex-direction:column;gap:2px;font-size:.78rem}
.expert-card__info strong{font-size:.88rem}
.expert-card__info span{color:var(--muted)}
.expert-card__info em{font-style:normal;color:var(--primary);font-size:.72rem}

/* Sidebar */
.feed-layout{display:grid;grid-template-columns:1fr 300px;gap:32px;align-items:start}
.sidebar__card{background:var(--surface);border:1px solid var(--border);border-radius:var(--radius);padding:20px;margin-bottom:16px}
.sidebar__card h3{font-size:.9rem;margin-bottom:12px}
.sidebar-group-link{display:flex;justify-content:space-between;padding:8px 0;font-size:.85rem;border-bottom:1px solid var(--border)}
.sidebar-group-link span{color:var(--muted);font-size:.75rem}
.topic-list,.topic-grid{display:flex;flex-wrap:wrap;gap:8px}
.topic-tag{padding:6px 14px;border:1px solid var(--border);border-radius:999px;font-size:.78rem;color:var(--primary)}
.topic-tag:hover{background:var(--primary);color:#fff}

/* Post detail & comments */
.post-detail{background:var(--surface);border:1px solid var(--border);border-radius:var(--radius);padding:28px;margin-bottom:32px}
.comments-section h2{font-size:1.1rem;margin-bottom:16px}
.comment-form{display:flex;gap:10px;margin-bottom:20px}
.comment-form input{flex:1;padding:12px;border:1px solid var(--border);border-radius:var(--radius);background:var(--bg)}
.comment-item{display:flex;gap:12px;padding:14px 0;border-bottom:1px solid var(--border)}
.comment-item img{width:36px;height:36px;border-radius:50%;object-fit:cover}
.comment-item p{font-size:.88rem;line-height:1.6}
.comment-item time{font-size:.72rem;color:var(--muted)}

/* Publish */
.publish-form label{display:block;margin-bottom:16px;font-size:.85rem;color:var(--muted)}
.publish-form textarea,.publish-form input,.publish-form select{width:100%;margin-top:6px;padding:12px;border:1px solid var(--border);border-radius:var(--radius);background:var(--bg)}

/* Groups */
.groups-grid{display:grid;grid-template-columns:repeat(auto-fill,minmax(280px,1fr));gap:20px}
.group-card{background:var(--surface);border:1px solid var(--border);border-radius:var(--radius);overflow:hidden}
.group-card img{width:100%;aspect-ratio:16/9;object-fit:cover}
.group-card__body{padding:20px}
.group-card__cat{font-size:.68rem;padding:2px 8px;border-radius:999px;background:rgba(0,0,0,.06);color:var(--primary);display:inline-block;margin-bottom:6px}
.group-card__body h3{margin-bottom:6px}
.group-card__body p{font-size:.85rem;color:var(--muted);margin-bottom:12px;line-height:1.6}
.group-card__meta{font-size:.78rem;color:var(--muted)}

/* Events */
.events-list{display:flex;flex-direction:column;gap:16px}
.event-card{display:grid;grid-template-columns:200px 1fr auto;gap:20px;align-items:center;padding:20px;background:var(--surface);border:1px solid var(--border);border-radius:var(--radius)}
.event-card img{width:100%;aspect-ratio:16/10;object-fit:cover;border-radius:var(--radius)}
.event-card h3{margin-bottom:6px}
.event-card p{font-size:.85rem;color:var(--muted)}
.event-card__type{font-size:.65rem;padding:2px 8px;border-radius:999px;display:inline-block;margin-right:6px;margin-bottom:4px}
.event-card__type--online{background:#dbeafe;color:#1d4ed8}
.event-card__type--offline{background:#dcfce7;color:#15803d}
.event-card__cat{font-size:.68rem;color:var(--primary)}

/* Profile */
.profile-header{display:flex;gap:24px;align-items:center;padding:32px;background:var(--surface);border:1px solid var(--border);border-radius:var(--radius);margin-bottom:24px}
.profile-header img{width:80px;height:80px;border-radius:50%;object-fit:cover}
.profile-header h1{font-size:1.4rem;margin-bottom:4px}
.profile-header p{color:var(--muted);font-size:.9rem}

/* Messages */
.msg-list{display:flex;flex-direction:column;gap:8px}
.msg-item{display:flex;gap:14px;padding:16px;background:var(--surface);border:1px solid var(--border);border-radius:var(--radius);align-items:center}
.msg-item.is-unread{border-color:var(--primary);background:rgba(0,0,0,.02)}
.msg-item__icon{width:40px;height:40px;border-radius:50%;background:rgba(0,0,0,.06);flex-shrink:0;display:grid;place-items:center;font-size:1rem}
.msg-item p{font-size:.88rem;flex:1}
.msg-item time{font-size:.72rem;color:var(--muted);flex-shrink:0}

/* Discover */
.discover-grid{display:grid;gap:18px}
.discover-section h2{font-size:1.1rem;margin-bottom:16px}

/* Auth */
.auth-card{padding:32px;background:var(--surface);border:1px solid var(--border);border-radius:var(--radius)}
.auth-tabs{display:flex;border-bottom:1px solid var(--border);margin-bottom:24px}
.auth-tab{flex:1;padding:12px;background:none;border:none;cursor:pointer;color:var(--muted)}
.auth-tab.is-active{color:var(--primary);font-weight:600;border-bottom:2px solid var(--primary)}
.auth-form label{display:block;margin-bottom:14px;font-size:.85rem;color:var(--muted)}
.auth-form input{width:100%;margin-top:6px;padding:12px;border:1px solid var(--border);border-radius:var(--radius)}
.auth-form h2{margin-bottom:20px;font-size:1.15rem}
.auth-tip{margin-top:16px;text-align:center;color:var(--primary)}

/* Buttons */
.btn{display:inline-flex;align-items:center;justify-content:center;padding:10px 20px;border-radius:var(--radius);border:none;cursor:pointer;font-size:.82rem;font-weight:600;transition:all .2s}
.btn--primary{background:var(--primary);color:#fff}
.btn--primary:hover{background:var(--primary-dark)}
.btn--outline{background:transparent;border:2px solid var(--primary);color:var(--primary)}
.btn--ghost{background:transparent;border:1px solid var(--border);color:var(--muted)}
.btn--sm{padding:8px 14px;font-size:.75rem}
.btn--block{display:flex;width:100%}

/* Footer enterprise */
.footer{padding:40px 24px 28px;border-top:1px solid var(--border);background:var(--surface)}
.footer__inner{max-width:1280px;margin:0 auto;display:grid;grid-template-columns:2fr repeat(3,1fr);gap:32px;margin-bottom:28px}
.footer__brand p{font-size:.82rem;color:var(--muted);line-height:1.6;margin-top:8px;max-width:280px}
.footer__brand .logo{font-size:1.1rem;margin-bottom:4px;display:inline-block}
.footer__col h4{font-size:.78rem;font-weight:700;margin-bottom:12px;color:var(--text);letter-spacing:.05em}
.footer__col a{display:block;font-size:.78rem;color:var(--muted);padding:4px 0;transition:color .2s}
.footer__col a:hover{color:var(--primary)}
.footer__bottom{max-width:1140px;margin:0 auto;padding-top:20px;border-top:1px solid var(--border);text-align:center;font-size:.72rem;color:var(--muted)}

.toast{position:fixed;bottom:24px;left:50%;transform:translateX(-50%);padding:12px 24px;background:var(--text);color:var(--surface);border-radius:var(--radius);opacity:0;transition:opacity .3s;z-index:200;pointer-events:none}
.toast.is-show{opacity:1}

@media(max-width:1024px){
  .category-grid{grid-template-columns:repeat(4,1fr)}
  .stats-bar{grid-template-columns:repeat(3,1fr)}
  .stat-item:nth-child(4),.stat-item:nth-child(5){grid-column:span 1}
  .footer__inner{grid-template-columns:1fr 1fr}
}

@media(max-width:768px){
  .nav{display:none;position:absolute;top:60px;left:0;right:0;flex-direction:column;background:var(--surface);padding:16px;border-bottom:1px solid var(--border)}
  .header.nav-open .nav{display:flex}
  .nav-toggle{display:block}
  .feed-layout{grid-template-columns:1fr}
  .sidebar{border-right:none;border-top:1px solid var(--border);padding-top:24px}
  .category-grid{grid-template-columns:repeat(3,1fr)}
  .stats-bar{grid-template-columns:repeat(2,1fr)}
  .bento-hero{grid-template-columns:1fr}
  .event-card{grid-template-columns:1fr}
  .category-header{flex-direction:column}
  .footer__inner{grid-template-columns:1fr}
  .announcement-item{flex-direction:column;align-items:flex-start;gap:4px}
  .announcement-item strong,.announcement-item__text{max-width:100%;white-space:normal}
}

/* === 布局密度优化：减少留白、提升信息密度与视觉层次 === */
.container,.header__inner,.footer__inner,.hero__content,.hero-strip__inner{max-width:1280px;padding-left:20px;padding-right:20px}
.page{padding:20px 0 36px}
.page__sub{margin-bottom:14px}
.section__title{margin:18px 0 12px;font-size:1.1rem}
.stats-bar,.metric-cards{margin-bottom:16px}
.stat-item,.metric-card{padding:12px 10px}
.stat-item__num{font-size:clamp(1rem,2vw,1.35rem)}
.category-grid{grid-template-columns:repeat(auto-fill,minmax(100px,1fr));gap:8px;margin-bottom:16px}
.category-card{padding:10px 6px}
.hero{min-height:240px}
.hero--compact{min-height:160px}
.hero__content{padding:24px 20px}
.sidebar-layout{display:grid;grid-template-columns:1fr 300px;gap:20px;align-items:start}
.feed-layout{display:grid;grid-template-columns:1fr 300px;gap:20px;align-items:start}
.feed{gap:12px}
.post-card{padding:14px 16px}
.discover-grid{gap:18px}
.home-split{display:grid;grid-template-columns:1fr 300px;gap:20px;align-items:start}
.dept-grid,.product-grid,.course-grid,.articles-grid,.cases-grid{gap:14px}
.category-header{padding:18px;margin-bottom:16px}
.announcement-bar{padding:12px 16px;margin-bottom:16px}
.feed-tabs{margin-bottom:14px;padding-bottom:8px}
.expert-grid{gap:10px}
.wiki-list{gap:12px}
.bento-grid{gap:12px;margin-bottom:16px}
.footer{padding:28px 20px 20px}
.footer__inner{gap:24px;margin-bottom:16px}
.empty-state{padding:32px 16px}
@media(max-width:900px){
  .sidebar-layout,.feed-layout,.home-split{grid-template-columns:1fr}
}

:root{--bg:#0c0a14;--surface:#16122a;--text:#f5f3ff;--muted:#a89fc4;--primary:#a855f7;--primary-dark:#7c3aed;--accent:#06b6d4;--border:#2e2640;--radius:20px;--shadow:0 0 40px rgba(168,85,247,.25)}
body{font-family:"PingFang SC","Microsoft YaHei",sans-serif;background:var(--bg);color:var(--text)}
.logo{background:linear-gradient(90deg,var(--primary),var(--accent));-webkit-background-clip:text;-webkit-text-fill-color:transparent;font-weight:800}
.page--bento{padding-top:24px}
.bento-hero{display:grid;grid-template-columns:2fr 1fr;gap:16px;margin-bottom:24px;min-height:220px}
.bento-hero__main{border-radius:var(--radius);background-size:cover;background-position:center;position:relative;overflow:hidden}
.bento-hero__text{position:absolute;inset:0;display:flex;flex-direction:column;justify-content:flex-end;padding:24px;background:linear-gradient(transparent,rgba(12,10,20,.85))}
.bento-hero__side{background:var(--surface);border:1px solid var(--border);border-radius:var(--radius);padding:20px}
.feed--bento{display:grid;grid-template-columns:repeat(auto-fill,minmax(280px,1fr));gap:16px}
.post-card{background:var(--surface);border:1px solid var(--border)}
.post-card:hover{box-shadow:var(--shadow);border-color:var(--primary)}