:root {
  color-scheme: light dark;
  --bg: #f5f6f8;
  --card: #ffffff;
  --text: #1a1d21;
  --muted: #6b7280;
  --border: #e2e5e9;
  --accent: #2563eb;
  --danger: #dc2626;
  --ok: #16a34a;
}

@media (prefers-color-scheme: dark) {
  :root {
    --bg: #14161a;
    --card: #1d2025;
    --text: #eef0f2;
    --muted: #9aa1ab;
    --border: #2c3036;
    --accent: #4f8cff;
    --danger: #f87171;
    --ok: #4ade80;
  }
}

* { box-sizing: border-box; }

body {
  margin: 0;
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, sans-serif;
  background: var(--bg);
  color: var(--text);
}

#app {
  max-width: 780px;
  margin: 0 auto;
  padding: 24px 16px 64px;
}

header {
  display: flex;
  justify-content: space-between;
  align-items: center;
  margin-bottom: 24px;
}

header h1 { font-size: 1.25rem; margin: 0; }

button {
  font: inherit;
  border: 1px solid var(--border);
  background: var(--card);
  color: var(--text);
  border-radius: 6px;
  padding: 6px 12px;
  cursor: pointer;
}
button.primary { background: var(--accent); color: white; border-color: var(--accent); }
button.danger { color: var(--danger); border-color: var(--danger); }
button:disabled { opacity: 0.5; cursor: default; }

input {
  font: inherit;
  border: 1px solid var(--border);
  background: var(--card);
  color: var(--text);
  border-radius: 6px;
  padding: 8px 10px;
}

.card {
  background: var(--card);
  border: 1px solid var(--border);
  border-radius: 10px;
  padding: 16px;
  margin-bottom: 16px;
}

.login-card { max-width: 340px; margin: 80px auto; }
.login-card h1 { font-size: 1.1rem; margin-top: 0; }
.field { margin-bottom: 12px; display: flex; flex-direction: column; gap: 4px; }
.field label { font-size: 0.85rem; color: var(--muted); }
.field input { width: 100%; }
.error { color: var(--danger); font-size: 0.85rem; min-height: 1.2em; }

.device-row {
  display: flex;
  align-items: center;
  gap: 12px;
}
.status-dot {
  width: 10px; height: 10px; border-radius: 50%;
  background: var(--muted); flex: none;
}
.status-dot.online { background: var(--ok); }

.device-main { flex: 1; min-width: 0; }
.device-name { font-weight: 600; }
.device-sub { font-size: 0.85rem; color: var(--muted); }

.remaining { font-size: 1.4rem; font-weight: 700; }
.remaining.zero { color: var(--danger); }

.controls { display: flex; gap: 6px; flex-wrap: wrap; margin-top: 10px; }

.budget-edit { display: flex; align-items: center; gap: 6px; margin-top: 10px; }
.budget-edit input { width: 90px; }

.usage-bars { display: flex; align-items: flex-end; gap: 4px; height: 60px; margin-top: 12px; }
.usage-bar { flex: 1; background: var(--accent); border-radius: 3px 3px 0 0; min-height: 2px; position: relative; }
.usage-bar-label { font-size: 0.65rem; color: var(--muted); text-align: center; margin-top: 4px; }

.events-list { margin-top: 10px; font-size: 0.85rem; color: var(--muted); }
.events-list div { padding: 3px 0; border-bottom: 1px solid var(--border); }

.toggle-link { font-size: 0.85rem; color: var(--accent); cursor: pointer; background: none; border: none; padding: 0; }

.enroll-box { margin-top: 12px; }
.enroll-code { font-size: 1.6rem; letter-spacing: 2px; font-weight: 700; text-align: center; padding: 12px; background: var(--bg); border-radius: 8px; margin: 8px 0; }
.hint { font-size: 0.8rem; color: var(--muted); }

.empty-state { text-align: center; color: var(--muted); padding: 40px 0; }