body {
  font-family: 'Segoe UI', Arial, sans-serif;
  background: #f8fafc;
  color: #23272f;
  margin: 0;
  padding: 0;
}

header {
  background: #2d3a4a;
  color: #fff;
  text-align: center;
  padding: 2rem 1rem 1rem 1rem;
}

main {
  display: flex;
  justify-content: center;
  align-items: flex-start;
  min-height: 80vh;
  padding: 2rem 0;
}

.accordion-container {
  width: 60%;
  min-width: 300px;
  background: #fff;
  border-radius: 12px;
  box-shadow: 0 4px 24px rgba(44,62,80,0.10);
  padding: 2rem 1.5rem;
}

.accordion {
  width: 100%;
}

.accordion-item {
  border-bottom: 1px solid #e0e6ed;
}

.accordion-header {
  background: none;
  border: none;
  outline: none;
  width: 100%;
  text-align: left;
  padding: 1.1rem 0;
  font-size: 1.1rem;
  font-weight: 600;
  color: #2d3a4a;
  cursor: pointer;
  position: relative;
  transition: background 0.2s;
}

.accordion-header::after {
  content: '+';
  position: absolute;
  right: 0;
  font-size: 1.3rem;
  transition: transform 0.2s;
}

.accordion-item.active .accordion-header::after {
  content: '-';
  transform: rotate(180deg);
}

.accordion-body {
  max-height: 0;
  overflow: hidden;
  background: #f3f7fa;
  transition: max-height 0.3s ease;
  padding: 0 0.5rem;
}

.accordion-item.active .accordion-body {
  padding: 1rem 0.5rem;
  max-height: 300px;
  transition: max-height 0.5s cubic-bezier(0.4,0,0.2,1);
}

footer {
  background: #2d3a4a;
  color: #fff;
  text-align: center;
  padding: 1rem 0;
  font-size: 1rem;
  margin-top: 2rem;
}

@media (max-width: 900px) {
  .accordion-container {
    width: 90%;
    padding: 1rem 0.5rem;
  }
  main {
    padding: 1rem 0;
  }
}

@media (max-width: 600px) {
  .accordion-header {
    font-size: 1rem;
    padding: 0.9rem 0;
  }
  .accordion-body {
    font-size: 0.97rem;
  }
}