/* Main stylesheet for Mathematics for Physics I website */

:root {
  --primary-color: #0047AB;
  --secondary-color: #4682B4;
  --light-blue: #e6f2ff;
  --background-color: #f8fbff;
  --text-color: #333333;
  --box-shadow: 0 4px 6px rgba(0, 0, 0, 0.1);
}

body {
  font-family: 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif;
  line-height: 1.6;
  color: var(--text-color);
  background-color: var(--background-color);
  margin: 0;
  padding: 0;
}

.container {
  max-width: 1200px;
  margin: 0 auto;
  padding: 0 20px;
}

/* Header styles */
header {
  background: linear-gradient(to right, var(--primary-color), var(--secondary-color));
  color: white;
  padding: 1rem 0;
  box-shadow: var(--box-shadow);
}

.site-title {
  font-size: 1.8rem;
  margin: 0;
}

.site-description {
  font-size: 1rem;
  margin: 0.5rem 0 0;
  opacity: 0.9;
}

/* Navigation styles */
.main-nav {
  background-color: white;
  box-shadow: var(--box-shadow);
}

.nav-list {
  display: flex;
  list-style: none;
  margin: 0;
  padding: 0;
  overflow-x: auto;
}

.nav-item {
  margin: 0;
  padding: 0;
}

.nav-link {
  display: block;
  padding: 1rem;
  color: var(--text-color);
  text-decoration: none;
  font-weight: 500;
  transition: all 0.3s ease;
}

.nav-link:hover, .nav-link.active {
  color: var(--primary-color);
  background-color: var(--light-blue);
}

/* Main content styles */
main {
  padding: 2rem 0;
}

.page-title {
  color: var(--primary-color);
  border-bottom: 3px solid var(--secondary-color);
  padding-bottom: 0.5rem;
  margin-bottom: 2rem;
}

.content-section {
  margin-bottom: 3rem;
}

.section-title {
  color: var(--secondary-color);
  margin-bottom: 1rem;
}

/* Card styles */
.card {
  background-color: white;
  border-radius: 8px;
  box-shadow: var(--box-shadow);
  padding: 1.5rem;
  margin-bottom: 1.5rem;
}

.card-title {
  color: var(--primary-color);
  margin-top: 0;
  margin-bottom: 1rem;
}

/* Math content styles */
.math-formula {
  margin: 1.5rem 0;
  overflow-x: auto;
}

.formula-box {
  background-color: var(--light-blue);
  border-radius: 8px;
  padding: 1rem;
  margin: 1rem 0;
}

/* Visualization container */
.viz-container {
  width: 100%;
  height: 400px;
  background-color: white;
  border-radius: 8px;
  overflow: hidden;
  margin: 1.5rem 0;
  box-shadow: var(--box-shadow);
}

/* Grid layouts */
.grid-2col {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 1.5rem;
}

.grid-3col {
  display: grid;
  grid-template-columns: 1fr 1fr 1fr;
  gap: 1.5rem;
}

/* Feature boxes */
.feature-box {
  background-color: var(--light-blue);
  border-radius: 8px;
  padding: 1.5rem;
  margin-bottom: 1.5rem;
}

.feature-icon {
  color: var(--primary-color);
  font-size: 2rem;
  margin-bottom: 1rem;
}

/* Footer styles */
footer {
  background-color: var(--primary-color);
  color: white;
  padding: 2rem 0;
  margin-top: 3rem;
}

.footer-content {
  display: flex;
  justify-content: space-between;
  flex-wrap: wrap;
}

.footer-section {
  flex: 1;
  min-width: 250px;
  margin-bottom: 1.5rem;
}

.footer-title {
  font-size: 1.2rem;
  margin-bottom: 1rem;
}

.footer-link {
  color: white;
  opacity: 0.8;
  text-decoration: none;
}

.footer-link:hover {
  opacity: 1;
  text-decoration: underline;
}

/* Navigation controls */
.page-navigation {
  display: flex;
  justify-content: space-between;
  margin-top: 3rem;
  padding-top: 1rem;
  border-top: 1px solid #ddd;
}

.nav-button {
  display: inline-block;
  padding: 0.5rem 1rem;
  background-color: var(--primary-color);
  color: white;
  text-decoration: none;
  border-radius: 4px;
  transition: background-color 0.3s ease;
}

.nav-button:hover {
  background-color: var(--secondary-color);
}

/* Responsive styles */
@media (max-width: 768px) {
  .grid-2col, .grid-3col {
    grid-template-columns: 1fr;
  }
  
  .nav-list {
    flex-direction: column;
  }
  
  .footer-content {
    flex-direction: column;
  }
}

/* Utility classes */
.text-center {
  text-align: center;
}

.mb-1 {
  margin-bottom: 0.5rem;
}

.mb-2 {
  margin-bottom: 1rem;
}

.mb-3 {
  margin-bottom: 1.5rem;
}

.mt-1 {
  margin-top: 0.5rem;
}

.mt-2 {
  margin-top: 1rem;
}

.mt-3 {
  margin-top: 1.5rem;
}