:root {
    --bg: #f3f4f6; --card: #fff; --text: #111827; --muted: #6b7280;
    --on: #16a34a; --on-bg: #dcfce7; --bad: #dc2626; --border: #e5e7eb;
}
@media (prefers-color-scheme: dark) {
    :root { --bg: #111827; --card: #1f2937; --text: #f9fafb; --muted: #9ca3af;
            --on: #4ade80; --on-bg: #14532d; --border: #374151; }
}
* { box-sizing: border-box; }
body { margin: 0; font: 16px/1.4 system-ui, sans-serif; background: var(--bg); color: var(--text); }
header { display: flex; align-items: center; gap: 12px; padding: 12px 16px; flex-wrap: wrap; }
header h1 { margin: 0; font-size: 22px; flex: 1; }
.conn { font-size: 13px; padding: 2px 8px; border-radius: 99px; background: var(--border); }
.conn.ok { background: var(--on-bg); color: var(--on); }
.conn.bad { background: var(--bad); color: #fff; }
.logout { color: var(--muted); font-size: 13px; text-decoration: none; }
.grid { display: grid; grid-template-columns: repeat(auto-fill, minmax(150px, 1fr)); gap: 10px; padding: 0 16px 16px; }
.relay { display: flex; flex-direction: column; align-items: flex-start; gap: 4px; min-height: 92px; padding: 12px;
         border: 2px solid var(--border); border-radius: 14px; background: var(--card); color: var(--text);
         font: inherit; text-align: left; cursor: pointer; }
.relay .num { font-size: 12px; color: var(--muted); }
.relay .name { font-weight: 600; flex: 1; }
.relay .state { font-size: 13px; font-weight: 700; color: var(--muted); }
.relay.on { border-color: var(--on); background: var(--on-bg); }
.relay.on .state { color: var(--on); }
footer { display: flex; gap: 10px; padding: 0 16px 24px; }
button { font: inherit; }
footer button, .card button { padding: 10px 16px; border-radius: 10px; border: 0; background: var(--on); color: #fff; cursor: pointer; }
footer button.danger { background: var(--bad); }
.login { display: grid; place-items: center; min-height: 100vh; padding: 16px; }
.card { display: flex; flex-direction: column; gap: 10px; width: 100%; max-width: 320px; padding: 24px;
        background: var(--card); border-radius: 16px; }
.card h1 { margin: 0 0 8px; }
.card input { padding: 10px; border-radius: 10px; border: 1px solid var(--border); background: var(--bg); color: var(--text); font: inherit; }
.err { color: var(--bad); margin: 0; }