@import url("https://fonts.googleapis.com/css2?family=Frank+Ruhl+Libre:wght@400;700&display=swap");

:root {
  --primary-color: #2d1810;
  --secondary-color: #8b4513;
  --accent-color: #c17817;
  --background-color: #f4e4bc;
  --card-color: #fffaf0;
  --text-shadow: 2px 2px 4px rgba(0, 0, 0, 0.3);
}

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

body {
  font-family: "Frank Ruhl Libre", serif;
  background-color: var(--background-color);
  background-image: url("https://www.transparenttextures.com/patterns/parchment.png");
  line-height: 1.6;
}

header {
  background-color: var(--primary-color);
  color: var(--card-color);
  text-align: center;
  padding: 4rem 2rem;
  margin-bottom: 2rem;
  box-shadow: 0 4px 15px rgba(0, 0, 0, 0.2);
}

header h1 {
  font-size: 3rem;
  text-shadow: var(--text-shadow);
  color: #ffd700;
}

.subtitle {
  color: #deb887;
  margin-top: 1rem;
  font-size: 1.5rem;
  text-shadow: var(--text-shadow);
}

.principles-container {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(320px, 1fr));
  gap: 2rem;
  padding: 2rem;
  max-width: 1400px;
  margin: 0 auto;
}

.principle-card {
  background: var(--card-color);
  border-radius: 15px;
  margin-bottom: 1rem;
  position: relative;
  transition: all 0.3s ease;
  border: 2px solid var(--secondary-color);
  box-shadow: 0 8px 16px rgba(0, 0, 0, 0.1);
  background-image: url("https://www.transparenttextures.com/patterns/cream-paper.png");
  overflow: hidden;
}

.principle-header {
  padding: 1.2rem;
  gap: 1rem;
  display: flex;
  justify-content: space-between;
  align-items: center;
  cursor: pointer;
  background: linear-gradient(to right, var(--card-color), #f4e4bc);
}

.principle-header h3 {
  margin: 0;
  color: var(--primary-color);
  font-size: 1.1rem;
  text-shadow: 1px 1px 2px rgba(0, 0, 0, 0.2);
  line-height: 1.4;
  flex: 1;
  padding-left: 1rem;
}

.toggle-icon {
  font-size: 1.5rem;
  color: var(--accent-color);
  transition: transform 0.3s ease;
  font-weight: bold;
}

.principle-card.active .toggle-icon {
  transform: rotate(45deg);
}

.principle-content {
  max-height: 0;
  overflow: hidden;
  transition: max-height 0.3s ease-out;
  padding: 0 1.5rem;
}

.principle-card.active .principle-content {
  max-height: 800px;
  padding: 1.5rem;
  border-top: 1px solid var(--secondary-color);
}

.principle-card:hover {
  transform: translateY(-2px);
  box-shadow: 0 12px 20px rgba(0, 0, 0, 0.15);
}

@keyframes cardAppear {
  from {
    opacity: 0;
    transform: translateY(20px);
  }
  to {
    opacity: 1;
    transform: translateY(0);
  }
}

.principle-card {
  animation: cardAppear 0.5s ease-out forwards;
}

footer {
  text-align: center;
  padding: 2rem;
  background-color: var(--primary-color);
  color: var(--card-color);
  margin-top: 2rem;
  box-shadow: 0 -4px 15px rgba(0, 0, 0, 0.2);
}

@media (max-width: 768px) {
  .principles-container {
    grid-template-columns: 1fr;
    padding: 1rem;
  }

  header h1 {
    font-size: 2rem;
  }

  .principle-card {
    margin: 1rem;
  }
}

.principle-content p {
  font-size: 1rem;
  line-height: 1.6;
  color: var(--secondary-color);
  text-align: justify;
  padding: 0.5rem;
}

.additional-info {
  margin-top: 1.5rem;
  padding: 1rem;
  background: rgba(255, 255, 255, 0.7);
  border-radius: 8px;
}

.additional-info h4 {
  color: var(--accent-color);
  margin: 1rem 0 0.5rem;
  font-size: 1.1rem;
  border-bottom: 1px solid var(--secondary-color);
  padding-bottom: 0.3rem;
}

.additional-info ul {
  list-style-type: none;
  padding-right: 1.2rem;
}

.additional-info li {
  position: relative;
  margin: 0.5rem 0;
  padding-right: 1.2rem;
}

.additional-info li::before {
  content: "◆";
  position: absolute;
  right: -1.2rem;
  color: var(--accent-color);
  font-size: 0.8rem;
}

.main-explanation {
  font-size: 1.1rem;
  color: var(--primary-color);
  border-right: 3px solid var(--accent-color);
  padding-right: 1rem;
  margin-bottom: 1rem;
}