:root{
  --bg:#f7f6f3; --card:#ffffff; --ink:#1a1a1a; --dim:#8a8a8a;
  --line:#e6e4df; --accent:#ff9d00; --accent-ink:#b35c00;
  --radius:14px; --maxw:1280px;
}
*{box-sizing:border-box}
body{
  margin:0; background:var(--bg); color:var(--ink);
  font-family:-apple-system,BlinkMacSystemFont,"Segoe UI","PingFang SC","Microsoft YaHei",sans-serif;
  line-height:1.55;
}
a{color:inherit;text-decoration:none}
.dim{color:var(--dim)}
.container{max-width:var(--maxw);margin:0 auto;padding:24px 20px 60px}

/* header */
.site-header{background:var(--bg);border-bottom:1px solid var(--line);position:sticky;top:0;z-index:20;backdrop-filter:saturate(1.2) blur(6px)}
.header-inner{max-width:var(--maxw);margin:0 auto;padding:12px 20px;display:flex;align-items:center;justify-content:space-between}
.brand{font-weight:700;font-size:18px;display:flex;gap:8px;align-items:center}
.top-nav a{color:var(--dim);font-size:14px}
.top-nav a:hover{color:var(--ink)}

/* page head */
.page-head{display:flex;flex-wrap:wrap;gap:20px;justify-content:space-between;align-items:flex-end;margin-bottom:18px}
.page-title h1{font-size:30px;margin:0;font-weight:800}
.page-title h1 .dim{font-size:18px;font-weight:500}
.subtitle{margin:4px 0 0;color:var(--dim);font-size:14px}

.view-controls{display:flex;gap:16px;align-items:center;flex-wrap:wrap}
.view-tabs{display:flex;background:var(--card);border:1px solid var(--line);border-radius:999px;padding:3px}
.view-tabs .tab{padding:6px 16px;border-radius:999px;font-size:14px;color:var(--dim);font-weight:600}
.view-tabs .tab.active{background:var(--ink);color:#fff}
.date-nav{display:flex;align-items:center;gap:6px;background:var(--card);border:1px solid var(--line);border-radius:999px;padding:4px 6px}
.nav-btn{width:28px;height:28px;display:grid;place-items:center;border-radius:50%;font-size:18px;color:var(--ink)}
.nav-btn:hover{background:var(--bg)}
.nav-label{font-size:14px;font-weight:600;padding:0 6px;white-space:nowrap}

/* date jump chips */
.date-jump{display:flex;gap:6px;flex-wrap:wrap;align-items:center;margin-bottom:22px;font-size:13px}
.date-chip{background:var(--card);border:1px solid var(--line);border-radius:8px;padding:4px 8px;color:var(--dim)}
.date-chip em{font-style:normal;color:var(--accent-ink);font-weight:700;margin-left:2px}
.date-chip.on{border-color:var(--ink);color:var(--ink)}
.date-chip:hover{border-color:var(--ink)}

/* grid */
.paper-grid{display:grid;grid-template-columns:repeat(auto-fill,minmax(300px,1fr));gap:18px}
.paper-card{background:var(--card);border:1px solid var(--line);border-radius:var(--radius);overflow:hidden;display:flex;flex-direction:column;transition:box-shadow .15s,transform .15s}
.paper-card:hover{box-shadow:0 6px 24px rgba(0,0,0,.08);transform:translateY(-2px)}
.card-thumb{position:relative;display:block;aspect-ratio:16/10;background:#f0eee9;overflow:hidden}
.card-thumb img{width:100%;height:100%;object-fit:cover;display:block}
.thumb-placeholder{width:100%;height:100%;display:grid;place-items:center;color:var(--dim);font-size:13px}
.card-date{position:absolute;left:8px;top:8px;background:rgba(0,0,0,.6);color:#fff;font-size:11px;padding:2px 7px;border-radius:6px}
.card-body{padding:12px 14px 14px;display:flex;flex-direction:column;gap:8px;flex:1}
.card-title{display:block}
.card-title .zh{font-weight:700;font-size:15px;line-height:1.4;display:block}
.card-title .en{font-size:12px;color:var(--dim);display:block;margin-top:3px}
.card-meta{display:flex;flex-wrap:wrap;gap:10px;font-size:12px;color:var(--dim);margin-top:auto}
.card-meta .upvotes{color:var(--accent-ink);font-weight:700}
.card-meta .org{color:#3a6ea5;font-weight:600}

/* empty */
.empty{text-align:center;padding:80px 20px;color:var(--dim)}
.empty code{background:var(--card);border:1px solid var(--line);padding:2px 6px;border-radius:6px}

/* detail */
.back-link{display:inline-block;margin-bottom:16px;color:var(--dim);font-size:14px}
.back-link:hover{color:var(--ink)}
.detail{max-width:860px;margin:0 auto}
.detail-title-zh{font-size:28px;font-weight:800;margin:0 0 6px}
.detail-title-en{font-size:16px;color:var(--dim);margin:0 0 14px;font-style:italic}
.detail-meta{display:flex;flex-wrap:wrap;gap:14px;font-size:14px;color:var(--dim);margin-bottom:10px}
.detail-meta .upvotes{color:var(--accent-ink);font-weight:700}
.detail-meta .org{color:#3a6ea5;font-weight:600}
.detail-authors{font-size:13px;color:var(--dim);margin:0 0 14px}
.detail-links{display:flex;gap:10px;flex-wrap:wrap;margin-bottom:24px}
.detail-links a{background:var(--card);border:1px solid var(--line);border-radius:8px;padding:6px 14px;font-size:13px;font-weight:600}
.detail-links a:hover{border-color:var(--ink)}
.detail-media{display:flex;flex-direction:column;gap:16px;margin-bottom:28px}
.detail-media img,.detail-media video{width:100%;border-radius:12px;border:1px solid var(--line);background:#fff}
.detail-abstract h2{font-size:18px;margin:0 0 12px;border-left:3px solid var(--accent);padding-left:10px}
.abs-zh{font-size:16px;line-height:1.9;margin:0 0 16px}
.abs-en-wrap summary{cursor:pointer;color:var(--dim);font-size:14px;font-weight:600}
.abs-en{color:#444;line-height:1.8;font-size:14px;margin-top:10px}

/* footer */
.site-footer{border-top:1px solid var(--line);padding:24px 20px;text-align:center;color:var(--dim);font-size:13px}

@media(max-width:640px){
  .page-title h1{font-size:24px}
  .paper-grid{grid-template-columns:1fr}
  .view-controls{width:100%;justify-content:space-between}
}
.site-footer p{margin:4px 0;line-height:1.8}
.site-footer a{color:inherit;text-decoration:none}
.site-footer a:hover{text-decoration:underline}