:root {
  --bg: #f4f6f9;
  --card: #ffffff;
  --text: #1f2328;
  --muted: #5c6570;
  --hint: #8a929c;
  --border: #e4e8ee;
  --border-strong: #d3d9e0;
  --brand: #2563eb;
  --brand-ink: #1d4ed8;
  --brand-soft: #eef4ff;
  --danger: #dc2626;
  --danger-soft: #fdecec;
  --success: #15803d;
  --success-soft: #e9f7ef;
  --warn: #b45309;
  --warn-soft: #fdf3e2;
  --radius: 12px;
  --shadow: 0 1px 3px rgba(16, 24, 40, .06), 0 1px 2px rgba(16, 24, 40, .04);
}

* { box-sizing: border-box; }

html, body {
  margin: 0;
  padding: 0;
  background: var(--bg);
  color: var(--text);
  font-family: -apple-system, BlinkMacSystemFont, "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei", sans-serif;
  font-size: 14px;
  line-height: 1.65;
  -webkit-font-smoothing: antialiased;
}

a { color: var(--brand-ink); text-decoration: none; }
a:hover { text-decoration: underline; }

.topbar {
  background: var(--card);
  border-bottom: 1px solid var(--border);
  padding: 14px 0;
}
.topbar-inner {
  max-width: 960px; margin: 0 auto; padding: 0 20px;
  display: flex; align-items: center; justify-content: space-between; gap: 16px;
}
.brand { font-size: 16px; font-weight: 600; letter-spacing: .2px; display: flex; align-items: center; gap: 9px; }
.brand .dot { width: 10px; height: 10px; border-radius: 3px; background: var(--brand); display: inline-block; }
.topnav { display: flex; gap: 18px; font-size: 13px; }
.topnav a { color: var(--muted); }

.wrap { max-width: 960px; margin: 0 auto; padding: 32px 20px 64px; }
.wrap-narrow { max-width: 560px; }

.hero h1 { font-size: 24px; font-weight: 600; margin: 0 0 8px; letter-spacing: .2px; }
.hero p { color: var(--muted); margin: 0 0 26px; font-size: 14px; }

.card {
  background: var(--card); border: 1px solid var(--border); border-radius: var(--radius);
  padding: 24px; box-shadow: var(--shadow); margin-bottom: 20px;
}
.card h2 { font-size: 16px; font-weight: 600; margin: 0 0 4px; }
.card .sub { color: var(--muted); font-size: 13px; margin: 0 0 18px; }

label { display: block; font-size: 13px; font-weight: 500; margin: 0 0 6px; color: var(--text); }
.field { margin-bottom: 16px; }

input[type="text"], input[type="password"], input[type="number"], select, textarea {
  width: 100%; padding: 11px 13px; font-size: 14px; font-family: inherit; color: var(--text);
  background: #fff; border: 1px solid var(--border-strong); border-radius: 9px; outline: none;
  transition: border-color .15s, box-shadow .15s;
}
input:focus, select:focus, textarea:focus { border-color: var(--brand); box-shadow: 0 0 0 3px var(--brand-soft); }
input.code-input { letter-spacing: 2px; text-transform: uppercase; font-variant-numeric: tabular-nums; }

.btn {
  display: inline-flex; align-items: center; justify-content: center; gap: 8px;
  font-size: 14px; font-weight: 500; font-family: inherit; cursor: pointer;
  padding: 11px 20px; border-radius: 9px; border: 1px solid transparent;
  background: var(--brand); color: #fff; transition: background .15s, opacity .15s;
}
.btn:hover { background: var(--brand-ink); }
.btn:disabled { opacity: .55; cursor: not-allowed; }
.btn-block { width: 100%; }
.btn-ghost { background: #fff; color: var(--text); border-color: var(--border-strong); }
.btn-ghost:hover { background: #f7f9fc; }
.btn-danger { background: #fff; color: var(--danger); border-color: #f0c4c4; }
.btn-danger:hover { background: var(--danger-soft); }
.btn-sm { padding: 6px 12px; font-size: 13px; border-radius: 7px; }

.msg { border-radius: 9px; padding: 12px 14px; font-size: 13px; margin-bottom: 16px; display: none; }
.msg.show { display: block; }
.msg-error { background: var(--danger-soft); color: var(--danger); border: 1px solid #f3cccc; }
.msg-ok { background: var(--success-soft); color: var(--success); border: 1px solid #c9e9d6; }
.msg-info { background: var(--brand-soft); color: var(--brand-ink); border: 1px solid #d5e3ff; }
.msg-warn { background: var(--warn-soft); color: var(--warn); border: 1px solid #f4dcb4; }

.muted { color: var(--muted); }
.hint { color: var(--hint); font-size: 13px; }
.mono { font-family: ui-monospace, SFMono-Regular, "SF Mono", Menlo, Consolas, monospace; }
.tag {
  display: inline-block; font-size: 12px; padding: 2px 9px; border-radius: 20px;
  background: var(--brand-soft); color: var(--brand-ink); font-weight: 500;
}
.tag-gray { background: #eef0f3; color: var(--muted); }
.tag-red { background: var(--danger-soft); color: var(--danger); }
.tag-green { background: var(--success-soft); color: var(--success); }

.grid { display: grid; gap: 16px; }
.grid-3 { grid-template-columns: repeat(3, 1fr); }
.grid-4 { grid-template-columns: repeat(4, 1fr); }
@media (max-width: 700px) { .grid-3, .grid-4 { grid-template-columns: 1fr 1fr; } }

.stat { background: var(--card); border: 1px solid var(--border); border-radius: var(--radius); padding: 18px; }
.stat .n { font-size: 26px; font-weight: 600; letter-spacing: .3px; }
.stat .l { color: var(--muted); font-size: 13px; margin-top: 2px; }

table { width: 100%; border-collapse: collapse; font-size: 13px; }
th, td { text-align: left; padding: 11px 12px; border-bottom: 1px solid var(--border); vertical-align: middle; }
th { color: var(--muted); font-weight: 500; font-size: 12px; text-transform: none; background: #fafbfc; }
tbody tr:hover { background: #fafbfd; }
.table-wrap { overflow-x: auto; border: 1px solid var(--border); border-radius: var(--radius); background: #fff; }

.device-row { display: flex; align-items: center; justify-content: space-between; gap: 14px; padding: 13px 0; border-bottom: 1px solid var(--border); }
.device-row:last-child { border-bottom: none; }
.device-row .meta { font-size: 13px; color: var(--muted); }

.my-item { display: flex; align-items: center; justify-content: space-between; padding: 12px 0; border-bottom: 1px solid var(--border); }
.my-item:last-child { border-bottom: none; }

.divider { height: 1px; background: var(--border); margin: 20px 0; }
.row { display: flex; gap: 12px; align-items: flex-end; flex-wrap: wrap; }
.row > * { flex: 1; min-width: 140px; }
.row .grow-0 { flex: 0 0 auto; min-width: 0; }

.footer { text-align: center; color: var(--hint); font-size: 12px; padding: 28px 20px; }

.spinner { width: 15px; height: 15px; border: 2px solid rgba(255,255,255,.5); border-top-color: #fff; border-radius: 50%; animation: spin .7s linear infinite; }
@keyframes spin { to { transform: rotate(360deg); } }

/* 阅读器 */
.reader-shell { max-width: 1040px; margin: 0 auto; padding: 22px 20px 60px; }
.reader-bar { display: flex; align-items: center; justify-content: space-between; gap: 14px; margin-bottom: 16px; flex-wrap: wrap; }
.content-frame { background: #fff; border: 1px solid var(--border); border-radius: var(--radius); padding: 30px; box-shadow: var(--shadow); }
.content-frame h1 { font-size: 22px; margin-top: 0; }

.lock { text-align: center; padding: 60px 20px; }
.lock .big { font-size: 40px; margin-bottom: 10px; }