/* Critical CSS for above-the-fold content */
:root {
  --primary-color: #4f46e5;
  --primary-hover: #4338ca;
  --text-color: #111827;
  --text-light: #6b7280;
  --bg-color: #ffffff;
  --bg-light: #f3f4f6;
}

/* Base styles */
body {
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "Helvetica Neue", Arial, sans-serif;
  color: var(--text-color);
  background-color: var(--bg-color);
  line-height: 1.5;
  margin: 0;
  padding: 0;
}

/* Layout containers */
.container {
  width: 100%;
  padding-right: 1rem;
  padding-left: 1rem;
  margin-right: auto;
  margin-left: auto;
}

@media (min-width: 640px) {
  .container {
    max-width: 640px;
  }
}

@media (min-width: 768px) {
  .container {
    max-width: 768px;
  }
}

@media (min-width: 1024px) {
  .container {
    max-width: 1024px;
  }
}

@media (min-width: 1280px) {
  .container {
    max-width: 1280px;
  }
}

/* Header styles */
header {
  background-color: var(--bg-color);
  box-shadow: 0 1px 3px 0 rgba(0, 0, 0, 0.1), 0 1px 2px 0 rgba(0, 0, 0, 0.06);
}

nav {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 1rem;
}

/* Typography */
h1 {
  font-size: 1.875rem;
  font-weight: 700;
  margin-bottom: 1rem;
  line-height: 1.25;
}

h2 {
  font-size: 1.5rem;
  font-weight: 700;
  margin-bottom: 0.75rem;
  line-height: 1.25;
}

h3 {
  font-size: 1.25rem;
  font-weight: 600;
  margin-bottom: 0.5rem;
  line-height: 1.25;
}

p {
  margin-top: 0;
  margin-bottom: 1rem;
}

/* Links */
a {
  color: var(--primary-color);
  text-decoration: none;
}

a:hover {
  color: var(--primary-hover);
  text-decoration: underline;
}

/* Buttons */
.btn {
  display: inline-block;
  font-weight: 500;
  text-align: center;
  white-space: nowrap;
  vertical-align: middle;
  user-select: none;
  border: 1px solid transparent;
  padding: 0.5rem 1rem;
  font-size: 1rem;
  line-height: 1.5;
  border-radius: 0.25rem;
  transition: color 0.15s ease-in-out, background-color 0.15s ease-in-out, border-color 0.15s ease-in-out, box-shadow 0.15s ease-in-out;
}

.btn-primary {
  color: #fff;
  background-color: var(--primary-color);
  border-color: var(--primary-color);
}

.btn-primary:hover {
  color: #fff;
  background-color: var(--primary-hover);
  border-color: var(--primary-hover);
}

/* Card styles */
.card {
  position: relative;
  display: flex;
  flex-direction: column;
  min-width: 0;
  word-wrap: break-word;
  background-color: #fff;
  background-clip: border-box;
  border: 1px solid rgba(0, 0, 0, 0.125);
  border-radius: 0.25rem;
  overflow: hidden;
}

/* Image placeholders */
.image-placeholder {
  background: linear-gradient(110deg, #ececec 8%, #f5f5f5 18%, #ececec 33%);
  background-size: 200% 100%;
  animation: 1.5s shine linear infinite;
  height: 0;
  padding-bottom: 56.25%; /* 16:9 aspect ratio */
}

@keyframes shine {
  to {
    background-position-x: -200%;
  }
}

/* Lazy loading */
.lazy-image {
  opacity: 0;
  transition: opacity 0.3s ease-in-out;
}

.lazy-loaded {
  opacity: 1;
}

/* Breadcrumbs */
.breadcrumb {
  display: flex;
  flex-wrap: wrap;
  padding: 0.75rem 1rem;
  margin-bottom: 1rem;
  list-style: none;
  background-color: var(--bg-light);
  border-radius: 0.25rem;
}

.breadcrumb-item + .breadcrumb-item {
  padding-left: 0.5rem;
}

.breadcrumb-item + .breadcrumb-item::before {
  display: inline-block;
  padding-right: 0.5rem;
  color: var(--text-light);
  content: "/";
}