:root {
  color-scheme: light dark;
  --bg: #ffffff;
  --fg: #1a1a1a;
  --muted: #6b7280;
  --border: #e5e7eb;
  --accent: #2563eb;
  --good: #16a34a;
  --bad: #dc2626;
  --card-bg: #f9fafb;
}

@media (prefers-color-scheme: dark) {
  :root {
    --bg: #12141a;
    --fg: #e8eaed;
    --muted: #9aa1ac;
    --border: #2a2d35;
    --accent: #6ea8fe;
    --good: #4ade80;
    --bad: #f87171;
    --card-bg: #1a1d24;
  }
}

* { box-sizing: border-box; }

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

.topnav {
  display: flex;
  align-items: center;
  gap: 1.5rem;
  padding: 1rem 1.5rem;
  border-bottom: 1px solid var(--border);
}

.topnav .brand {
  font-weight: 700;
  margin-right: 1rem;
}

.topnav a {
  color: var(--muted);
  text-decoration: none;
}

.topnav a:hover {
  color: var(--fg);
}

.content {
  max-width: 1000px;
  margin: 0 auto;
  padding: 1.5rem;
}

.card {
  background: var(--card-bg);
  border: 1px solid var(--border);
  border-radius: 8px;
  padding: 1.25rem;
  margin-bottom: 1.25rem;
}

table {
  width: 100%;
  border-collapse: collapse;
}

th, td {
  text-align: left;
  padding: 0.5rem 0.75rem;
  border-bottom: 1px solid var(--border);
}

th {
  color: var(--muted);
  font-weight: 600;
  font-size: 0.85rem;
  text-transform: uppercase;
}

.savings-positive { color: var(--good); font-weight: 600; }
.savings-negative { color: var(--bad); }

.badge {
  display: inline-block;
  padding: 0.1rem 0.5rem;
  border-radius: 4px;
  font-size: 0.75rem;
  background: var(--border);
  color: var(--muted);
}

.badge.current { background: var(--accent); color: white; }
.badge.not-modelable { background: var(--bad); color: white; }

form.settings-form label {
  display: block;
  margin-top: 0.75rem;
  font-size: 0.9rem;
  color: var(--muted);
}

form.settings-form input, form.settings-form select {
  width: 100%;
  padding: 0.5rem;
  margin-top: 0.25rem;
  background: var(--bg);
  color: var(--fg);
  border: 1px solid var(--border);
  border-radius: 4px;
}

button {
  margin-top: 1rem;
  padding: 0.6rem 1.2rem;
  background: var(--accent);
  color: white;
  border: none;
  border-radius: 6px;
  cursor: pointer;
  font-size: 0.95rem;
}

.tou-period {
  border: 1px solid var(--border);
  border-radius: 6px;
  padding: 0.75rem;
  margin-top: 0.75rem;
}

.p-days-group {
  margin-top: 0.75rem;
  font-size: 0.9rem;
  color: var(--muted);
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 0.6rem;
}

form.settings-form label.p-day-label {
  display: inline-flex;
  align-items: center;
  gap: 0.25rem;
  margin-top: 0;
  width: auto;
  color: var(--fg);
  font-size: 0.85rem;
}

form.settings-form label.p-day-label input {
  width: auto;
  margin-top: 0;
}

.muted { color: var(--muted); font-size: 0.85rem; }
.chart-container { position: relative; height: 320px; margin-top: 0.75rem; }
.notes { font-size: 0.8rem; color: var(--muted); margin-top: 0.25rem; }