:root {
  --color-primary: #3b82f6;
  --color-secondary: #64748b;
  --color-accent: #f59e0b;
  --color-surface: #ffffff;
  --color-text: #0f172a;
  --color-success: #10b981;
  --color-warning: #f59e0b;
  --color-danger: #ef4444;
  --radius-sm: 4px;
  --radius-md: 8px;
  --radius-lg: 16px;
  --font-family: system-ui, sans-serif;
}

* { box-sizing: border-box; }
html, body { margin: 0; padding: 0; height: 100%; font-family: var(--font-family); background: var(--color-surface); color: var(--color-text); }
button { font: inherit; padding: 8px 16px; border: 0; border-radius: var(--radius-md); background: var(--color-primary); color: #fff; cursor: pointer; }
button[disabled] { opacity: .5; cursor: not-allowed; }
input { font: inherit; padding: 8px 12px; border: 1px solid var(--color-secondary); border-radius: var(--radius-sm); width: 100%; }
.container { max-width: 960px; margin: 0 auto; padding: 24px; }
.card { padding: 24px; border-radius: var(--radius-lg); box-shadow: 0 1px 4px rgba(0,0,0,.1); }
.led { display: inline-block; width: 10px; height: 10px; border-radius: 50%; border: 0; background-color: transparent; vertical-align: middle; }