:root{--bg:#f6f7f9;--card:#fff;--ink:#1f2937;--muted:#6b7280;--line:#e5e7eb;--brand:#1d4ed8}
*{box-sizing:border-box}body{margin:0;background:var(--bg);color:var(--ink);font:15px/1.6 -apple-system,"PingFang SC","Microsoft YaHei",sans-serif}
.topbar{display:flex;justify-content:space-between;align-items:center;background:#111827;color:#fff;padding:10px 18px}
.topbar a{color:#cbd5e1;margin-left:12px;text-decoration:none}.container{max-width:1080px;margin:0 auto;padding:18px}
.topnav{display:flex;gap:8px;align-items:center}
.nav-pill{display:inline-block;color:#e5e7eb;background:rgba(255,255,255,.08);border:1px solid rgba(255,255,255,.18);border-radius:999px;padding:5px 16px;margin-left:0;font-size:14px}
.nav-pill:hover{background:rgba(255,255,255,.16);color:#fff}
.nav-pill.active{background:var(--brand);border-color:var(--brand);color:#fff;font-weight:600}
.nav-pill.ghost{background:transparent}
.card{background:var(--card);border:1px solid var(--line);border-radius:10px;padding:16px;margin:14px 0}
.cards{display:grid;grid-template-columns:repeat(auto-fit,minmax(180px,1fr));gap:12px}
.kpi{background:var(--card);border:1px solid var(--line);border-radius:10px;padding:14px}.kpi .k{color:var(--muted);font-size:13px}.kpi .v{font-size:24px;font-weight:700}
.muted{color:var(--muted);font-size:13px}.err{color:#b91c1c}
table{width:100%;border-collapse:collapse;margin-top:8px}th,td{border-bottom:1px solid var(--line);padding:7px 8px;text-align:left;font-variant-numeric:tabular-nums}
input,button{font-size:14px;padding:8px 10px;border:1px solid var(--line);border-radius:8px}
button{cursor:pointer;background:#f3f4f6}button.primary,button.active{background:var(--brand);color:#fff;border-color:var(--brand)}
.toolbar{display:flex;gap:8px;align-items:center;flex-wrap:wrap;margin-bottom:8px}
.form-row{display:flex;gap:12px;flex-wrap:wrap;margin:10px 0;align-items:flex-end}
.login-card{max-width:420px;margin:60px auto;text-align:center}.login-card input{width:100%}
#pw{width:100%;margin:10px 0}
.editor{min-height:220px;border:1px solid var(--line);border-radius:8px;padding:10px;margin:10px 0}
.editor img{max-width:100%}
.letters{display:grid;gap:14px}.letter-card{background:#fff;border:1px solid var(--line);border-radius:10px;padding:16px}
.letter-card .cover{max-width:100%;border-radius:8px}.letter-row{display:flex;gap:10px;align-items:center;padding:6px 0;border-bottom:1px solid var(--line)}
.footer{max-width:1080px;margin:20px auto;padding:0 18px;color:var(--muted);font-size:12px}
.chart-wrap{position:relative}
.chart-wrap-single{position:relative}
.chart-opts{display:inline-flex;gap:8px;margin-left:auto}
.chart-opts button{background:#fff;box-shadow:0 1px 4px rgba(0,0,0,.12)}
.chart-opts button.active{background:var(--brand);color:#fff;border-color:var(--brand)}
.tabs{display:flex;gap:8px;margin-bottom:12px}
.tabs button{border-radius:999px;padding:6px 18px}
.tabs button.active{background:var(--brand);color:#fff;border-color:var(--brand)}
.toggle-pill{border-radius:999px;font-size:13px;padding:4px 14px}
.feed{display:grid;gap:12px}
.feed-item{background:#fff;border:1px solid var(--line);border-radius:10px;padding:12px 14px}
.feed-item .meta{color:var(--muted);font-size:13px;margin:2px 0 8px}
.feed-item .body img{max-width:100%;border-radius:8px}
.composer{display:grid;gap:8px;margin-bottom:12px}
.composer textarea{min-height:90px;border:1px solid var(--line);border-radius:8px;padding:10px;font-size:14px;resize:vertical}
.composer .row{display:flex;gap:8px;align-items:center;flex-wrap:wrap}