:root {
  --bg-primary: #ffffff;
  --bg-secondary: #f5f5f5;
  --text-primary: #1a1a1a;
  --text-secondary: #666666;
  --accent: #0066cc;
  --accent-hover: #0052a3;
  --border: #e0e0e0;
  --shadow: rgba(0, 0, 0, 0.1);
}

/* Theme classes (always applied by JavaScript) */
.dark-theme {
  --bg-primary: #1a1a1a;
  --bg-secondary: #2a2a2a;
  --text-primary: #e0e0e0;
  --text-secondary: #a0a0a0;
  --accent: #4da6ff;
  --accent-hover: #66b3ff;
  --border: #3a3a3a;
  --shadow: rgba(0, 0, 0, 0.3);
}

.light-theme {
  --bg-primary: #ffffff;
  --bg-secondary: #f5f5f5;
  --text-primary: #1a1a1a;
  --text-secondary: #666666;
  --accent: #0066cc;
  --accent-hover: #0052a3;
  --border: #e0e0e0;
  --shadow: rgba(0, 0, 0, 0.1);
}

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

html, body {
  width: 100%;
  height: 100%;
  overflow-x: hidden;
}

body {
  font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, Oxygen, Ubuntu, Cantarell, sans-serif;
  line-height: 1.6;
  color: var(--text-primary);
  background-color: var(--bg-primary);
  display: flex;
  flex-direction: column;
  transition: background-color 0.3s ease, color 0.3s ease;
}

/* Custom Scrollbar */
::-webkit-scrollbar {
  width: 12px;
  height: 12px;
}

::-webkit-scrollbar-track {
  background: var(--bg-secondary);
  border-radius: 10px;
}

::-webkit-scrollbar-thumb {
  background: var(--border);
  border-radius: 10px;
  border: 2px solid var(--bg-secondary);
  transition: background 0.2s ease;
}

::-webkit-scrollbar-thumb:hover {
  background: var(--text-secondary);
}

/* Firefox scrollbar */
* {
  scrollbar-width: thin;
  scrollbar-color: var(--border) var(--bg-secondary);
}

/* Header */
.site-header {
  background-color: var(--bg-secondary);
  border-bottom: 1px solid var(--border);
  padding: 1rem 0;
  position: sticky;
  top: 0;
  z-index: 100;
  transition: background-color 0.3s ease;
}

.site-nav {
  max-width: 1200px;
  min-width: 300px;
  margin: 0 auto;
  padding: 0 clamp(10px, 2vw, 2rem);
  display: flex;
  align-items: center;
  gap: 2rem;
}

.nav-link {
  color: var(--text-primary);
  text-decoration: none;
  font-weight: 500;
  transition: color 0.2s ease;
}

.nav-link:hover {
  color: var(--accent);
}

.theme-toggle {
  margin-left: auto;
  background-color: var(--bg-primary);
  border: 2px solid var(--border);
  border-radius: 50%;
  width: 2.5rem;
  height: 2.5rem;
  cursor: pointer;
  display: flex;
  align-items: center;
  justify-content: center;
  transition: background-color 0.2s ease, border-color 0.2s ease, transform 0.2s ease;
}

.theme-toggle:hover {
  border-color: var(--accent);
  transform: scale(1.1);
}

.theme-icon {
  font-size: 1.5rem;
  color: var(--text-primary);
  transition: color 0.2s ease;
}

/* Main Content */
.site-main {
  flex: 1;
  width: 100%;
  max-width: 1200px;
  min-width: 300px;
  margin: 0 auto;
  padding: clamp(10px, 2vw, 2rem);
  overflow-y: auto;
}

/* Home Page */
.home-title {
  font-size: 2.5rem;
  margin-bottom: 2rem;
  color: var(--text-primary);
}

.articles-list {
  display: flex;
  flex-direction: column;
  gap: 1.5rem;
}

.article-preview {
  padding: 1.5rem;
  background-color: var(--bg-secondary);
  border-radius: 8px;
  border: 1px solid var(--border);
  transition: transform 0.2s ease, box-shadow 0.2s ease;
}

.article-preview:hover {
  transform: translateY(-2px);
  box-shadow: 0 4px 12px var(--shadow);
}

.article-preview h2 {
  font-size: 1.5rem;
  margin-bottom: 0.5rem;
}

.article-preview h2 a {
  color: var(--text-primary);
  text-decoration: none;
  transition: color 0.2s ease;
}

.article-preview h2 a:hover {
  color: var(--accent);
}

.article-preview time {
  color: var(--text-secondary);
  font-size: 0.9rem;
}

/* Article Page */
.article {
  width: 100%;
  margin: 0;
}

.article-header {
  margin-bottom: 2rem;
  padding-bottom: 1rem;
  border-bottom: 2px solid var(--border);
}

.article-title {
  font-size: 2.5rem;
  margin-bottom: 0.5rem;
  color: var(--text-primary);
}

.article-date {
  color: var(--text-secondary);
  font-size: 1rem;
}

.article-content {
  font-size: 1.1rem;
  line-height: 1.8;
}

.article-content h1,
.article-content h2,
.article-content h3,
.article-content h4,
.article-content h5,
.article-content h6 {
  margin-top: 2rem;
  margin-bottom: 1rem;
  color: var(--text-primary);
}

.article-content h1 { font-size: 2rem; }
.article-content h2 { font-size: 1.75rem; }
.article-content h3 { font-size: 1.5rem; }
.article-content h4 { font-size: 1.25rem; }

.article-content p {
  margin-bottom: 1rem;
}

.article-content a {
  color: var(--accent);
  text-decoration: none;
}

.article-content a:hover {
  color: var(--accent-hover);
  text-decoration: underline;
}

.article-content img {
  max-width: 100%;
  height: auto;
  margin: 2rem 0;
  border-radius: 8px;
  box-shadow: 0 4px 12px var(--shadow);
}

.article-content video {
  max-width: 100%;
  height: auto;
  margin: 2rem 0;
  border-radius: 8px;
}

.article-content code {
  background-color: var(--bg-secondary);
  padding: 0.2rem 0.4rem;
  border-radius: 4px;
  font-family: 'Courier New', monospace;
  font-size: 0.9em;
}

.article-content pre {
  background-color: var(--bg-secondary);
  padding: 1rem;
  border-radius: 8px;
  overflow-x: auto;
  margin: 1rem 0;
}

.article-content pre code {
  background: none;
  padding: 0;
}

.article-content blockquote {
  border-left: 4px solid var(--accent);
  padding-left: 1rem;
  margin: 1rem 0;
  color: var(--text-secondary);
  font-style: italic;
}

.article-content ul,
.article-content ol {
  margin-left: 2rem;
  margin-bottom: 1rem;
}

.article-content li {
  margin-bottom: 0.5rem;
}

/* About Page */
.about {
  width: 100%;
  margin: 0;
}

.about h1 {
  font-size: 2.5rem;
  margin-bottom: 2rem;
  color: var(--text-primary);
}

.about p {
  font-size: 1.1rem;
  line-height: 1.8;
  margin-bottom: 1rem;
}

/* Responsive */
@media (max-width: 768px) {
  .site-nav {
    gap: 1rem;
  }

  .article-title,
  .home-title {
    font-size: 2rem;
  }

  .article-content {
    font-size: 1rem;
  }
}

@media (max-width: 320px) {
  .site-main {
    min-width: 300px;
  }
}