/* ======================================
   Buttons
   ====================================== */
.btn {
  display: inline-block;
  padding: 0.5rem 1rem;
  border-radius: 4px;
  border: 1px solid transparent;
  background-color: #f5f5f5;
  color: #333;
  font-size: 0.95rem;
  cursor: pointer;
  transition: background-color 0.2s ease, border-color 0.2s ease;
}

.btn:hover {
  background-color: #e6e6e6;
}

.btn:disabled {
  opacity: 0.6;
  cursor: not-allowed;
}

.btn-primary {
  background-color: #0077cc;
  color: #fff;
  border-color: #005fa3;
}

.btn-primary:hover {
  background-color: #005fa3;
}

.btn-secondary {
  background-color: #e0e0e0;
  color: #222;
  border-color: #ccc;
}

.btn-secondary:hover {
  background-color: #d5d5d5;
}

/* ======================================
   Charts
   ====================================== */
.chart-canvas {
  position: relative;
  width: 100%;
  height: 400px;
  background-color: #fff;
  border: 1px solid #ccc;
  border-radius: 6px;
  box-shadow: 0 2px 4px rgba(0, 0, 0, 0.1);
}

@media (max-width: 768px) {
  .chart-canvas {
    height: 300px;
  }
}

@media (max-width: 480px) {
  .btn {
    font-size: 0.85rem;
    padding: 0.4rem 0.8rem;
  }
  .chart-canvas {
    height: 250px;
  }
}

/* ======================================
   Footer
   ====================================== */
footer {
  text-align: center;
  font-size: 0.8rem;
  color: #666;
  margin-top: 2rem;
}

footer::after {
  content: "© 2026 Donau2Space.de";
  display: block;
  margin-top: 0.5rem;
}