* { box-sizing: border-box; }
body {
  margin: 0;
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, sans-serif;
  background: #f4f6f5;
  color: #1d2422;
}
.page { max-width: 960px; margin: 0 auto; padding: 1rem; }
.topbar { display: flex; align-items: baseline; gap: 1.5rem; padding-bottom: 1rem; border-bottom: 1px solid #d8dfdb; }
.topbar h1 { margin: 0; font-size: 1.4rem; }
.topbar nav a { margin-right: 1rem; color: #2f6f4f; text-decoration: none; font-weight: 500; }
.topbar nav a.active { color: #1d2422; text-decoration: underline; }

main { padding-top: 1.5rem; }

.cards { display: grid; grid-template-columns: repeat(auto-fit, minmax(260px, 1fr)); gap: 1rem; }
.card { background: white; border-radius: 12px; padding: 1.5rem; box-shadow: 0 1px 3px rgba(0,0,0,0.08); }
.card h2 { margin: 0 0 0.5rem; color: #2f6f4f; }
.card .big { font-size: 2.4rem; margin: 0.25rem 0; font-weight: 600; }
.card dl { display: grid; grid-template-columns: auto 1fr; gap: 0.25rem 1rem; margin: 1rem 0 0; }
.card dt { color: #6b7672; font-size: 0.9rem; }
.card dd { margin: 0; }

.controls { margin-bottom: 1rem; }
.controls label { font-weight: 500; }
.controls select { margin-left: 0.5rem; padding: 0.4rem; }

.chart-wrap { background: white; border-radius: 12px; padding: 1rem; box-shadow: 0 1px 3px rgba(0,0,0,0.08); }
.chart-wrap canvas { max-height: 400px; }

.empty { color: #6b7672; font-style: italic; }
.meta { color: #6b7672; margin-top: 1rem; font-size: 0.85rem; }
.battery { color: #2f6f4f; font-weight: 500; }
.battery.medium { color: #b45309; }
.battery.low { color: #b91c1c; }

footer { margin-top: 2rem; padding-top: 1rem; border-top: 1px solid #d8dfdb; color: #6b7672; }