:root {
  --bg: #f5f6f8;
  --panel: #ffffff;
  --line: #e3e6ea;
  --text: #1f2328;
  --muted: #667085;
  --ok: #157f3c;
  --ok-bg: #e8f6ed;
  --off: #6b7280;
  --off-bg: #f0f1f3;
  --bad: #b42318;
  --accent: #1f5fd8;
}

* { box-sizing: border-box; }

body {
  margin: 0;
  background: var(--bg);
  color: var(--text);
  font: 15px/1.5 -apple-system, "Segoe UI", "PingFang SC", "Microsoft YaHei", sans-serif;
}

.topbar {
  background: var(--panel);
  border-bottom: 1px solid var(--line);
}

.topbar-inner {
  max-width: 960px;
  margin: 0 auto;
  padding: 16px 20px;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 12px;
  flex-wrap: wrap;
}

.brand h1 {
  font-size: 18px;
  margin: 0;
}

.brand-sub {
  color: var(--muted);
  font-size: 12px;
}

.stats {
  display: flex;
  gap: 16px;
  font-size: 14px;
  color: var(--muted);
}

.stats b {
  color: var(--text);
  font-size: 16px;
}

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

.panel,
.detail {
  background: var(--panel);
  border: 1px solid var(--line);
  border-radius: 10px;
  padding: 20px;
}

.panel {
  max-width: 420px;
}

h2 { font-size: 16px; margin: 0 0 8px; }
h3 { font-size: 15px; margin: 0; }

.hint,
.meta {
  color: var(--muted);
  font-size: 13px;
  margin: 0 0 16px;
}

label {
  display: block;
  font-size: 13px;
  color: var(--muted);
  margin-bottom: 6px;
}

input {
  width: 100%;
  padding: 10px 12px;
  border: 1px solid var(--line);
  border-radius: 8px;
  font-size: 15px;
  background: #fff;
  color: var(--text);
}

input:focus {
  outline: 2px solid rgba(31, 95, 216, .25);
  border-color: var(--accent);
}

button {
  margin-top: 12px;
  padding: 10px 16px;
  border: 1px solid var(--accent);
  background: var(--accent);
  color: #fff;
  border-radius: 8px;
  font-size: 14px;
  cursor: pointer;
}

button.ghost {
  background: #fff;
  color: var(--text);
  border-color: var(--line);
  margin-top: 0;
}

button:disabled { opacity: .55; cursor: default; }

.error { color: var(--bad); font-size: 13px; min-height: 18px; margin: 8px 0 0; }

.list-head {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 12px;
}

.list-actions { display: flex; gap: 8px; }

.devices {
  list-style: none;
  margin: 12px 0 0;
  padding: 0;
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 12px;
}

.device {
  display: block;
  width: 100%;
  text-align: left;
  background: var(--panel);
  border: 1px solid var(--line);
  border-radius: 10px;
  padding: 14px 16px;
  cursor: pointer;
  margin: 0;
  color: var(--text);
}

.device:hover { border-color: #c7ccd4; }
.device[aria-current="true"] { border-color: var(--accent); }

.device-top {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 8px;
}

.device-name { font-weight: 600; word-break: break-word; }

.device-platform,
.device-seen {
  display: block;
  color: var(--muted);
  font-size: 13px;
  margin-top: 4px;
}

.badge {
  font-size: 12px;
  padding: 2px 8px;
  border-radius: 999px;
  white-space: nowrap;
}

.badge.online { color: var(--ok); background: var(--ok-bg); }
.badge.offline { color: var(--off); background: var(--off-bg); }

.empty {
  color: var(--muted);
  background: var(--panel);
  border: 1px dashed var(--line);
  border-radius: 10px;
  padding: 24px;
  text-align: center;
}

.detail { margin-top: 16px; }

.detail-head {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 12px;
  margin-bottom: 12px;
}

dl {
  margin: 0 0 16px;
  display: grid;
  grid-template-columns: 120px 1fr;
  gap: 6px 12px;
  font-size: 14px;
}

dt { color: var(--muted); }
dd { margin: 0; word-break: break-all; }

.row { display: flex; gap: 8px; align-items: center; }
.row input { flex: 1; }
.row button { margin-top: 0; }

.result { font-size: 13px; color: var(--muted); min-height: 18px; }
.result.ok { color: var(--ok); }
.result.bad { color: var(--bad); }

@media (max-width: 640px) {
  .devices { grid-template-columns: 1fr; }
  .topbar-inner { padding: 14px 16px; }
  .wrap { padding: 16px; }
  dl { grid-template-columns: 1fr; }
  .row { flex-direction: column; align-items: stretch; }
}