/* Basic modern academic style */

* {
  box-sizing: border-box;
  margin: 0;
  padding: 0;
  font-family: sans-serif;
}

body {
  background-color: #f9f9f9;
  color: #333;
}

/* Container centered, with a max width */
.container {
  width: 80%;
  max-width: 1200px;
  margin: 2rem auto;
  text-align: center;
}

/* Title styling */
h1 {
  margin-bottom: 1.5rem;
  font-weight: 600;
}

/* Controls in a flexible row */
.controls {
  display: flex;
  flex-wrap: wrap;
  justify-content: center;
  margin-bottom: 2rem;
}

/* Each control group stacked vertically */
.control-group {
  margin: 0 1rem 1rem 1rem;
  display: flex;
  flex-direction: column;
  align-items: center;
}

.control-group label {
  margin-bottom: 0.5rem;
  font-weight: 500;
}

#charge1Sign,
#charge2Sign,
#charge1Mag,
#charge2Mag,
#gridResolution {
  margin-bottom: 0.5rem;
}

/* Make the canvas scale on smaller devices */
canvas {
  display: block;
  margin: 0 auto;
  max-width: 100%;
  height: auto; /* ensures proportionate resizing */
  touch-action: none;
}

/* =========================
   MEDIA QUERIES
   ========================= */

/* For tablets (max width ~ 768px) */
@media (max-width: 768px) {
  /* Reduce container width and spacing */
  .container {
    width: 90%;
    margin: 1rem auto;
  }

  .controls {
    flex-direction: column;
    align-items: center;
  }

  .control-group {
    margin: 0.5rem 0;
  }
}

/* For phones or very narrow screens (max width ~ 480px) */
@media (max-width: 480px) {
  h1 {
    font-size: 1.5rem;
    margin-bottom: 1rem;
  }

  .control-group label {
    font-size: 0.9rem;
  }
}