:root {
  --primary: #003366;
  --secondary: #007bff;
  --bg: #f4f7f6;
  --text: #333;
  --white: #fff;
  --error: #dc3545;
}

* { box-sizing: border-box; margin: 0; padding: 0; }

body {
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, Helvetica, Arial, sans-serif;
  background: var(--bg);
  color: var(--text);
  line-height: 1.6;
}

.container {
  max-width: 480px; /* Mobile first */
  margin: 0 auto;
  padding: 20px;
  min-height: 100vh;
  background: var(--white);
  box-shadow: 0 0 20px rgba(0,0,0,0.05);
}

/* Utilitários */
.btn {
  display: block;
  width: 100%;
  padding: 12px;
  background: var(--primary);
  color: white;
  border: none;
  border-radius: 6px;
  font-size: 1rem;
  cursor: pointer;
  margin-top: 10px;
}
.btn:disabled { opacity: 0.7; }
.input-group { margin-bottom: 15px; }
.input-group label { display: block; margin-bottom: 5px; font-weight: 500; }
.input-group input, .input-group select, .input-group textarea {
  width: 100%;
  padding: 10px;
  border: 1px solid #ddd;
  border-radius: 4px;
  font-size: 1rem;
}
.error-msg { color: var(--error); font-size: 0.9rem; margin-top: 5px; display: none; }
.hidden { display: none !important; }