:root{
  --primary:#0ea5a4; --primary-d:#0c8a89; --bg:#f5f7f8; --card:#fff;
  --text:#1f2d2d; --muted:#7a8a8a; --border:#e3e9e9; --ok:#16a34a; --warn:#d97706;
}
*{box-sizing:border-box}
body{margin:0;font-family:-apple-system,"PingFang SC","Microsoft YaHei",sans-serif;background:var(--bg);color:var(--text);line-height:1.6}
.wrap{max-width:760px;margin:0 auto;padding:0 16px}
.topbar{background:var(--primary);color:#fff;position:sticky;top:0;z-index:10;box-shadow:0 2px 8px rgba(0,0,0,.08)}
.topbar .wrap{display:flex;align-items:center;justify-content:space-between;height:54px}
.brand{color:#fff;font-weight:700;font-size:18px;text-decoration:none}
.topbar nav a{color:#e7fbfb;text-decoration:none;margin-left:14px;font-size:14px}
.topbar nav a:hover{color:#fff}
.hero{background:linear-gradient(135deg,#0ea5a4,#22c1c3);color:#fff;border-radius:14px;padding:28px 22px;margin:22px 0}
.hero h1{margin:0 0 6px;font-size:24px}
.hero p{margin:0 0 16px;opacity:.92}
.btn-primary{display:inline-block;background:var(--primary);color:#fff;border:none;padding:10px 18px;border-radius:10px;font-size:15px;cursor:pointer;text-decoration:none}
.btn-primary:hover{background:var(--primary-d)}
.btn-ghost{display:inline-block;color:var(--primary);border:1px solid var(--primary);padding:6px 12px;border-radius:8px;text-decoration:none;font-size:13px}
.btn-vote{background:#fff;color:var(--warn);border:1px solid var(--warn);padding:8px 14px;border-radius:10px;cursor:pointer;font-size:14px}
.demand-list{list-style:none;padding:0;margin:0}
.card{background:var(--card);border:1px solid var(--border);border-radius:12px;padding:16px;margin:12px 0}
.demand-title{font-size:17px;font-weight:600;color:var(--text);text-decoration:none}
.demand-desc{color:var(--muted);margin:6px 0;font-size:14px;white-space:pre-wrap}
.meta{color:var(--muted);font-size:13px;display:flex;gap:14px;flex-wrap:wrap;align-items:center;margin-top:6px}
.status-open{color:var(--warn);font-weight:600}
.status-done{color:var(--ok);font-weight:600}
.sec{font-size:18px;margin:22px 0 8px}
.detail h1{margin:0 0 8px;font-size:22px}
.back{display:inline-block;margin:16px 0;color:var(--primary);text-decoration:none}
.solution h3{margin:0 0 4px}
.res-url{word-break:break-all}
.form label{display:block;margin:10px 0;font-size:14px;color:var(--text)}
.form input,.form textarea{width:100%;margin-top:4px;padding:10px;border:1px solid var(--border);border-radius:8px;font-size:14px;font-family:inherit}
.form .hint{color:var(--muted);font-size:12px}
.empty{color:var(--muted);padding:30px 0;text-align:center}
.empty a,.hint a{color:var(--primary)}
.post-desc{white-space:pre-wrap;background:#f0f5f5;border-radius:8px;padding:12px;font-size:14px}
.foot{text-align:center;color:var(--muted);font-size:12px;padding:30px 0}
.muted{color:var(--muted)}