:root {
  --primary-color: #007BFF;
  --secondary-color: #4A5568;
  --background-color: #F7FAFC;
  --surface-color: #FFFFFF;
  --text-color: #2D3748;
  --border-color: #E2E8F0;
  --font-family: 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif;
}

/* General Reset & Body Styles */
*, *::before, *::after {
  box-sizing: border-box;
  margin: 0;
  padding: 0;
}

body {
  font-family: var(--font-family);
  line-height: 1.6;
  background-color: var(--background-color);
  color: var(--text-color);
  display: flex;
  flex-direction: column;
  min-height: 100vh;
}

h1, h2, h3, h4, h5, h6 {
  margin-bottom: 0.75rem;
  line-height: 1.2;
  color: var(--text-color);
}

h1 { font-size: 2.5rem; }
h2 { font-size: 2rem; }
h3 { font-size: 1.5rem; }

p {
  margin-bottom: 1rem;
}

a {
  color: var(--primary-color);
  text-decoration: none;
  transition: color 0.3s ease;
}

a:hover {
  color: #0056b3;
  text-decoration: underline;
}

img {
  max-width: 100%;
  height: auto;
}

ul, ol {
    margin-bottom: 1rem;
    padding-left: 20px;
}

.container {
  width: 90%;
  max-width: 1200px;
  margin: 0 auto;
}

/* Header & Navigation */
.site-header {
  background-color: var(--surface-color);
  padding: 1rem 0;
  border-bottom: 1px solid var(--border-color);
  position: sticky;
  top: 0;
  z-index: 1000;
}

.site-header .container {
  display: flex;
  justify-content: space-between;
  align-items: center;
  flex-wrap: wrap;
}

.site-title {
  font-size: 1.5rem;
  font-weight: bold;
}

.site-title a {
  text-decoration: none;
  color: var(--text-color);
}

.main-nav ul {
  list-style-type: none;
  display: flex;
  gap: 1.5rem;
}

.main-nav a {
  text-decoration: none;
  font-weight: 500;
  padding: 0.5rem 0;
  position: relative;
  color: var(--secondary-color);
}

.main-nav a::after {
  content: '';
  position: absolute;
  bottom: 0;
  left: 0;
  width: 0;
  height: 2px;
  background-color: var(--primary-color);
  transition: width 0.3s ease;
}

.main-nav a:hover::after {
  width: 100%;
}

/* Main Content Layout */
.main-grid {
  display: grid;
  grid-template-columns: 1fr;
  gap: 2rem;
  padding: 2rem 0;
}

@media (min-width: 768px) {
  .main-grid {
    grid-template-columns: 2fr 1fr;
  }
}

main {
  background-color: var(--surface-color);
  padding: 2rem;
  border-radius: 8px;
  box-shadow: 0 1px 3px rgba(0,0,0,0.1);
}

/* Article Cards (Homepage) */
.articles-grid {
  display: grid;
  gap: 1.5rem;
  grid-template-columns: 1fr;
}

@media (min-width: 1024px) {
  .articles-grid {
    grid-template-columns: repeat(2, 1fr);
  }
}

.card {
  border: 1px solid var(--border-color);
  border-radius: 8px;
  overflow: hidden;
  background-color: var(--surface-color);
  transition: transform 0.3s ease, box-shadow 0.3s ease;
}

.card:hover {
  transform: translateY(-5px);
  box-shadow: 0 4px 12px rgba(0,0,0,0.1);
}

.card-content {
  padding: 1.5rem;
}

.card-content h3 {
  margin-top: 0;
}

.read-more-btn {
  display: inline-block;
  margin-top: 1rem;
  font-weight: bold;
}

/* Sidebar (Aside) */
aside .widget {
  background-color: var(--surface-color);
  padding: 1.5rem;
  border-radius: 8px;
  box-shadow: 0 1px 3px rgba(0,0,0,0.1);
  margin-bottom: 2rem;
}

aside .widget-title {
  font-size: 1.25rem;
  border-bottom: 2px solid var(--primary-color);
  padding-bottom: 0.5rem;
  margin-bottom: 1rem;
}

aside .widget ul {
  list-style: none;
  padding: 0;
}

aside .widget li {
  margin-bottom: 0.75rem;
}

aside .widget a {
  font-weight: 500;
}

/* Article Page */
.article-header h1 {
    margin-bottom: 0.5rem;
}

.article-meta {
    font-size: 0.9rem;
    color: var(--secondary-color);
    margin-bottom: 2rem;
}

.article-content h2, .article-content h3 {
    margin-top: 2rem;
}

.cta-section {
    background-color: #e3f2fd;
    border-left: 5px solid var(--primary-color);
    padding: 1.5rem;
    margin: 2rem 0;
    border-radius: 4px;
}

/* Footer */
.site-footer {
  background-color: var(--text-color);
  color: #a0aec0;
  padding: 2rem 0;
  margin-top: auto;
  text-align: center;
}

.site-footer .container {
    display: flex;
    flex-direction: column;
    gap: 1rem;
}

@media (min-width: 768px) {
    .site-footer .container {
        flex-direction: row;
        justify-content: space-between;
        align-items: center;
    }
}

.footer-links {
  list-style: none;
  padding: 0;
  display: flex;
  gap: 1.5rem;
  justify-content: center;
}