:root {
  color-scheme: light dark;
  font-family: Inter, ui-sans-serif, system-ui, -apple-system, BlinkMacSystemFont, "Segoe UI", sans-serif;
  --bg: #f3f4f6;
  --surface: #ffffff;
  --text: #111827;
  --muted: #6b7280;
  --border: #d1d5db;
  --primary: #1d4ed8;
  --danger: #b91c1c;
  --success: #047857;
}
* { box-sizing: border-box; }
body { margin: 0; background: var(--bg); color: var(--text); min-height: 100dvh; }
button, input, textarea, select { font: inherit; }
button { min-height: 48px; border-radius: 12px; border: 1px solid var(--border); background: var(--surface); color: var(--text); padding: .75rem 1rem; font-weight: 700; cursor: pointer; }
button:disabled { opacity: .5; cursor: not-allowed; }
input, textarea, select { width: 100%; border: 1px solid var(--border); border-radius: 10px; padding: .75rem; background: var(--surface); color: var(--text); }
label { display: grid; gap: .4rem; font-weight: 600; }
.app-shell { max-width: 720px; margin: 0 auto; min-height: 100dvh; padding-bottom: calc(1rem + env(safe-area-inset-bottom)); }
.topbar { position: sticky; top: 0; z-index: 5; display: flex; justify-content: space-between; gap: 1rem; align-items: center; padding: calc(.8rem + env(safe-area-inset-top)) 1rem .8rem; background: #111827; color: white; box-shadow: 0 2px 10px #0003; }
.topbar strong, .topbar span { display: block; }
.status-stack { display: flex; gap: .4rem; flex-wrap: wrap; justify-content: flex-end; }
.badge { border: 1px solid #ffffff44; border-radius: 999px; padding: .25rem .5rem; font-size: .75rem; }
.badge[data-state="connected"], .badge[data-state="online"] { background: #065f46; }
.badge[data-state="error"], .badge[data-state="offline"] { background: #991b1b; }
main { padding: 1rem; display: grid; gap: 1rem; }
.card { background: var(--surface); border: 1px solid var(--border); border-radius: 16px; padding: 1rem; box-shadow: 0 3px 14px #0000000d; display: grid; gap: .9rem; }
.card h1, .card h2, .card p { margin: 0; }
.muted { color: #d1d5db; font-size: .8rem; }
.eyebrow { color: var(--muted); text-transform: uppercase; letter-spacing: .08em; font-size: .72rem; font-weight: 800; }
.presence-card { grid-template-columns: 1fr minmax(140px, .6fr); align-items: center; }
.presence-card strong { display: block; font-size: 1.4rem; }
.primary { background: var(--primary); color: white; border-color: var(--primary); }
.danger { background: var(--danger); color: white; border-color: var(--danger); }
.success { background: var(--success); color: white; border-color: var(--success); }
.button-row { display: grid; grid-template-columns: 1fr 1fr; gap: .75rem; }
.control-grid { display: grid; grid-template-columns: 1fr 1fr; gap: .75rem; }
.wide { width: 100%; }
.incoming { border: 2px solid var(--success); }
.number { font-size: 1.2rem; font-variant-numeric: tabular-nums; }
.key-grid { display: grid; grid-template-columns: repeat(3, 1fr); gap: .6rem; }
.key-grid button { min-height: 58px; font-size: 1.25rem; }
.inline { display: flex; align-items: center; gap: .6rem; }
.inline input { width: auto; }
.error { color: var(--danger); min-height: 1.2rem; }
.link-button { width: 100%; background: transparent; border: 0; color: var(--primary); }
.toast { position: fixed; left: 50%; bottom: calc(1rem + env(safe-area-inset-bottom)); transform: translate(-50%, 150%); opacity: 0; transition: .2s; background: #111827; color: white; border-radius: 999px; padding: .75rem 1rem; max-width: calc(100vw - 2rem); z-index: 10; }
.toast.show { transform: translate(-50%, 0); opacity: 1; }
pre { white-space: pre-wrap; overflow-wrap: anywhere; background: #111827; color: #e5e7eb; padding: .8rem; border-radius: 10px; }
[hidden] { display: none !important; }
@media (prefers-color-scheme: dark) {
  :root { --bg: #030712; --surface: #111827; --text: #f9fafb; --muted: #9ca3af; --border: #374151; --primary: #2563eb; }
}
@media (min-width: 720px) { main { padding: 1.5rem; } }