h1 {
  color: #4a5f8a;
  margin-top: 0;
  margin-bottom: 25px;
}

.chart-box {
  background: white;
  border-radius: 12px;
  padding: 20px 30px;
  margin-bottom: 30px;
  box-shadow: 0 4px 15px rgba(0,0,0,0.08);
}

.chart-box h2 {
  color: #4a5f8a;
  margin-top: 0;
  margin-bottom: 15px;
  font-size: 1.1em;
}

.chart-canvas {
  position: relative;
  width: 100%;
  height: 420px; /* augmente la hauteur */
}

.chart-canvas canvas {
  width: 100% !important;
  height: 100% !important;
}

/* Responsive tablette */
@media (max-width: 900px) {
  .chart-box {
    padding: 18px 20px;
  }

  .chart-canvas {
    height: 320px;
  }
}

/* Responsive téléphone */
@media (max-width: 600px) {
  h1 {
    font-size: 1.8rem;
    margin-bottom: 18px;
  }

  .chart-box {
    padding: 16px;
    margin-bottom: 20px;
    border-radius: 10px;
  }

  .chart-box h2 {
    font-size: 1rem;
  }

  .chart-canvas {
    height: 240px;
  }
}