*, *::before, *::after { box-sizing: border-box; margin: 0; padding: 0; }
body { font-family: system-ui, sans-serif; background: #0f172a; color: #e2e8f0; min-height: 100vh; }
header { display: flex; align-items: center; justify-content: space-between; flex-wrap: wrap; gap: 1rem; padding: 1rem 1.5rem; background: #1e293b; border-bottom: 1px solid #334155; }
header h1 { font-size: 1.5rem; font-weight: 700; color: #38bdf8; }
.controls { display: flex; align-items: center; gap: 1rem; flex-wrap: wrap; }
.controls label { font-size: 0.875rem; color: #94a3b8; }
.controls select { background: #334155; color: #e2e8f0; border: 1px solid #475569; border-radius: 0.375rem; padding: 0.3rem 0.6rem; font-size: 0.875rem; }
#pollBtn { background: #0ea5e9; color: #fff; border: none; border-radius: 0.375rem; padding: 0.35rem 0.9rem; font-size: 0.875rem; cursor: pointer; }
#pollBtn:hover { background: #38bdf8; }
#pollBtn:disabled { background: #475569; }
#lastUpdated { font-size: 0.75rem; color: #64748b; }
main { padding: 1.5rem; display: flex; flex-direction: column; gap: 1.5rem; }
.cards { display: grid; grid-template-columns: repeat(auto-fill, minmax(180px, 1fr)); gap: 1rem; }
.card { background: #1e293b; border: 2px solid #334155; border-radius: 0.75rem; padding: 1rem 1.25rem; }
.card-name { font-size: 0.8rem; font-weight: 600; color: #94a3b8; text-transform: uppercase; margin-bottom: 0.5rem; }
.card-value { font-size: 2.25rem; font-weight: 700; color: #f1f5f9; }
.card-unit { font-size: 1rem; color: #94a3b8; margin-left: 2px; }
.card-ts { font-size: 0.7rem; color: #64748b; margin-top: 0.4rem; }
.chart-wrap { background: #1e293b; border-radius: 0.75rem; padding: 1.25rem; border: 1px solid #334155; }
canvas { max-height: 420px; }