:root{
  --bg:#f5f7fb; --card:#fff; --ink:#1f2733; --muted:#6b7686;
  --brand:#2f6bff; --brand-soft:#e8f0ff; --line:#e6eaf0; --ok:#1faa59;
}
*{box-sizing:border-box}
body{margin:0;font-family:-apple-system,BlinkMacSystemFont,"PingFang SC","Microsoft YaHei",sans-serif;
  background:var(--bg);color:var(--ink);line-height:1.6;-webkit-text-size-adjust:100%}
.topbar{display:flex;align-items:center;justify-content:space-between;padding:14px 18px;
  background:#fff;border-bottom:1px solid var(--line)}
.brand{font-size:22px;font-weight:800;color:var(--brand);letter-spacing:1px}
.brand-en{font-size:12px;color:var(--muted);margin-left:6px;font-weight:500}
.tagline{font-size:13px;color:var(--muted)}
.wrap{max-width:760px;margin:0 auto;padding:16px}
.card{background:var(--card);border:1px solid var(--line);border-radius:16px;
  padding:18px;margin-bottom:16px;box-shadow:0 2px 10px rgba(30,50,90,.04)}
.card h2{margin:0 0 12px;font-size:18px}
.card h2 small{font-size:12px;color:var(--muted);font-weight:500}
.search-row input{width:100%;padding:12px 14px;border:1px solid var(--line);border-radius:12px;
  font-size:16px;outline:none}
.search-row input:focus{border-color:var(--brand)}
.filters{display:flex;flex-wrap:wrap;gap:8px;margin:12px 0}
.chip{padding:6px 12px;border:1px solid var(--line);border-radius:999px;background:#fff;
  font-size:13px;color:var(--muted);cursor:pointer;user-select:none}
.chip.active{background:var(--brand);border-color:var(--brand);color:#fff}
.results{display:grid;gap:10px}
.item{border:1px solid var(--line);border-radius:12px;padding:12px 14px;background:#fff}
.item a{font-weight:600;color:var(--brand);text-decoration:none;font-size:15px}
.item .meta{font-size:12px;color:var(--muted);margin:4px 0}
.item .desc{font-size:13px;color:var(--ink)}
.tag{display:inline-block;font-size:11px;background:var(--brand-soft);color:var(--brand);
  border-radius:6px;padding:1px 7px;margin:2px 4px 0 0}
.hint{font-size:12px;color:var(--muted);margin:10px 0 0}
.ai-note{font-size:13px;color:var(--muted);margin:0 0 10px}
.ai-row{display:flex;gap:10px;margin-bottom:10px;flex-wrap:wrap}
.ai-row select{padding:10px;border:1px solid var(--line);border-radius:10px;font-size:14px;flex:1;min-width:120px}
textarea{width:100%;padding:12px;border:1px solid var(--line);border-radius:12px;font-size:15px;
  resize:vertical;outline:none;font-family:inherit}
textarea:focus{border-color:var(--brand)}
.btn-primary{margin-top:12px;width:100%;padding:13px;border:0;border-radius:12px;background:var(--brand);
  color:#fff;font-size:16px;font-weight:600;cursor:pointer}
.btn-primary:disabled{opacity:.6}
.ai-answer{margin-top:14px;padding:14px;border:1px solid var(--brand-soft);border-radius:12px;
  background:var(--brand-soft);white-space:pre-wrap;font-size:15px}
.foot{text-align:center;font-size:12px;color:var(--muted);padding:20px}