:root {
  --bg-color: #f8f9fa;
  --text-color: #333;
  --card-bg: #ffffff;
  --accent-color: #007bff;
  --heading-color: #111;
  --meta-color: #6c757d;
  --border-color: #e9ecef;
  --radius: 12px;
  --transition: 0.3s ease-in-out;
}

[data-theme="dark"] {
  --bg-color: #121212;
  --text-color: #e0e0e0;
  --card-bg: #1e1e1e;
  --accent-color: #4dabf7;
  --heading-color: #ffffff;
  --meta-color: #adb5bd;
  --border-color: #343a40;
}

body {
  font-family: 'Inter', -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "Helvetica Neue", Arial, sans-serif;
  background-color: var(--bg-color);
  color: var(--text-color);
  margin: 0;
  padding: 0;
  line-height: 1.6;
  transition: background-color var(--transition), color var(--transition);
}

header {
  background-color: var(--card-bg);
  box-shadow: 0 4px 6px rgba(0,0,0,0.05);
  padding: 1rem 5%;
  display: flex;
  justify-content: space-between;
  align-items: center;
  position: sticky;
  top: 0;
  z-index: 100;
  transition: background-color var(--transition);
}

.logo {
  font-size: 1.8rem;
  font-weight: 800;
  color: var(--heading-color);
  text-decoration: none;
  letter-spacing: -1px;
}

.logo span {
  color: var(--accent-color);
}

.theme-toggle {
  background: none;
  border: none;
  font-size: 1.5rem;
  cursor: pointer;
  color: var(--text-color);
}

.container {
  max-width: 1200px;
  margin: 2rem auto;
  padding: 0 20px;
}

.grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(300px, 1fr));
  gap: 2rem;
}

.card {
  background-color: var(--card-bg);
  border-radius: var(--radius);
  overflow: hidden;
  box-shadow: 0 4px 15px rgba(0,0,0,0.05);
  transition: transform var(--transition), box-shadow var(--transition);
  display: flex;
  flex-direction: column;
}

.card:hover {
  transform: translateY(-5px);
  box-shadow: 0 8px 25px rgba(0,0,0,0.1);
}

.card-img-wrap {
  position: relative;
  overflow: hidden;
  height: 200px;
}

.card img {
  width: 100%;
  height: 100%;
  object-fit: cover;
  transition: transform 0.5s;
}

.card:hover img {
  transform: scale(1.05);
}

.category-badge {
  position: absolute;
  top: 15px;
  left: 15px;
  background: var(--accent-color);
  color: #fff;
  padding: 4px 12px;
  border-radius: 20px;
  font-size: 0.8rem;
  font-weight: 600;
  text-transform: uppercase;
}

.card-content {
  padding: 1.5rem;
  flex-grow: 1;
  display: flex;
  flex-direction: column;
}

.card-title {
  font-size: 1.25rem;
  color: var(--heading-color);
  margin: 0 0 10px 0;
  font-weight: 700;
  line-height: 1.3;
}

.card-title a {
  color: inherit;
  text-decoration: none;
}

.card-title a:hover {
  color: var(--accent-color);
}

.card-excerpt {
  font-size: 0.95rem;
  color: var(--meta-color);
  margin-bottom: 1.5rem;
  flex-grow: 1;
}

.card-meta {
  font-size: 0.85rem;
  color: var(--meta-color);
  display: flex;
  justify-content: space-between;
  align-items: center;
  border-top: 1px solid var(--border-color);
  padding-top: 1rem;
}

/* Single Article */
.article-header {
  text-align: center;
  max-width: 800px;
  margin: 0 auto 2rem;
}

.article-title {
  font-size: 2.5rem;
  color: var(--heading-color);
  font-weight: 800;
  margin-bottom: 1rem;
  line-height: 1.2;
}

.article-meta {
  color: var(--meta-color);
  font-size: 0.95rem;
}

.article-image {
  max-width: 100%;
  height: auto;
  border-radius: var(--radius);
  margin-bottom: 2rem;
}

.article-content {
  max-width: 800px;
  margin: 0 auto;
  font-size: 1.1rem;
  line-height: 1.8;
  color: var(--text-color);
}

.article-content p {
  margin-bottom: 1.5rem;
}

.tags {
  display: flex;
  flex-wrap: wrap;
  gap: 10px;
  margin-top: 2rem;
}

.tag {
  background: var(--border-color);
  color: var(--text-color);
  padding: 5px 12px;
  border-radius: 6px;
  font-size: 0.85rem;
  text-decoration: none;
}

/* Ad Block */
.ad-block {
  background: linear-gradient(135deg, #007bff, #6610f2);
  color: white;
  padding: 2rem;
  border-radius: var(--radius);
  text-align: center;
  margin: 2rem 0;
  box-shadow: 0 4px 15px rgba(0,0,0,0.1);
}

.ad-block h3 {
  margin-top: 0;
  font-size: 1.5rem;
}

.btn {
  display: inline-block;
  background-color: #fff;
  color: var(--accent-color);
  padding: 10px 24px;
  border-radius: 30px;
  text-decoration: none;
  font-weight: 700;
  margin-top: 1rem;
  transition: transform var(--transition);
}

.btn:hover {
  transform: scale(1.05);
}