/* Shared styles for all pages */
* {
  margin: 0;
  padding: 0;
  box-sizing: border-box;
}

html {
  scroll-behavior: smooth;
}

:root {
  --bg-primary: #ffffff;
  --bg-secondary: #f8fafc;
  --bg-card: #ffffff;
  --text-primary: #1e293b;
  --text-secondary: #64748b;
  --text-muted: #94a3b8;
  --border-color: #e2e8f0;
  --accent: #3b82f6;
  --accent-hover: #2563eb;
  --accent-light: #dbeafe;
  --shadow: 0 1px 3px rgba(0,0,0,0.1);
  --shadow-lg: 0 10px 40px rgba(0,0,0,0.1);
}

[data-theme="dark"] {
  --bg-primary: #0f172a;
  --bg-secondary: #1e293b;
  --bg-card: #1e293b;
  --text-primary: #f1f5f9;
  --text-secondary: #94a3b8;
  --text-muted: #64748b;
  --border-color: #334155;
  --accent: #60a5fa;
  --accent-hover: #3b82f6;
  --accent-light: #1e3a5f;
  --shadow: 0 1px 3px rgba(0,0,0,0.3);
  --shadow-lg: 0 10px 40px rgba(0,0,0,0.4);
}

body {
  font-family: 'Inter', 'Noto Sans SC', -apple-system, BlinkMacSystemFont, sans-serif;
  line-height: 1.7;
  color: var(--text-primary);
  background: var(--bg-primary);
  transition: background 0.3s, color 0.3s;
}

.container {
  max-width: 1000px;
  margin: 0 auto;
  padding: 0 20px;
}

/* Header */
header {
  position: sticky;
  top: 0;
  z-index: 100;
  background: var(--bg-primary);
  border-bottom: 1px solid var(--border-color);
  transition: background 0.3s, border-color 0.3s;
}

.header-inner {
  display: flex;
  align-items: center;
  justify-content: space-between;
  height: 64px;
}

.logo {
  font-size: 1.5rem;
  font-weight: 700;
  color: var(--text-primary);
  text-decoration: none;
  display: flex;
  align-items: center;
  gap: 8px;
}

.logo-icon {
  width: 32px;
  height: 32px;
  background: linear-gradient(135deg, var(--accent), #8b5cf6);
  border-radius: 8px;
  display: flex;
  align-items: center;
  justify-content: center;
  color: white;
  font-weight: 700;
  font-size: 1rem;
}

nav {
  display: flex;
  align-items: center;
  gap: 24px;
}

nav a {
  color: var(--text-secondary);
  text-decoration: none;
  font-weight: 500;
  font-size: 0.95rem;
  transition: color 0.2s;
}

nav a:hover, nav a.active {
  color: var(--accent);
}

.theme-toggle {
  width: 40px;
  height: 40px;
  border: none;
  background: var(--bg-secondary);
  border-radius: 50%;
  cursor: pointer;
  display: flex;
  align-items: center;
  justify-content: center;
  transition: background 0.3s;
}

.theme-toggle:hover {
  background: var(--border-color);
}

.theme-toggle svg {
  width: 20px;
  height: 20px;
}

/* Hero Section */
.hero {
  padding: 80px 0;
  text-align: center;
  background: linear-gradient(180deg, var(--bg-secondary) 0%, var(--bg-primary) 100%);
}

.hero h1 {
  font-size: 3rem;
  font-weight: 700;
  margin-bottom: 16px;
  background: linear-gradient(135deg, var(--text-primary) 0%, var(--accent) 100%);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
}

.hero p {
  font-size: 1.25rem;
  color: var(--text-secondary);
  max-width: 600px;
  margin: 0 auto 32px;
}

.hero-links {
  display: flex;
  gap: 16px;
  justify-content: center;
}

.btn {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  padding: 12px 24px;
  border-radius: 10px;
  font-weight: 500;
  text-decoration: none;
  transition: all 0.3s;
}

.btn-primary {
  background: var(--accent);
  color: white;
}

.btn-primary:hover {
  background: var(--accent-hover);
  transform: translateY(-2px);
  box-shadow: var(--shadow-lg);
}

.btn-secondary {
  background: var(--bg-secondary);
  color: var(--text-primary);
  border: 1px solid var(--border-color);
}

.btn-secondary:hover {
  border-color: var(--accent);
}

/* Section */
section {
  padding: 60px 0;
}

.section-title {
  font-size: 1.75rem;
  font-weight: 700;
  margin-bottom: 32px;
  display: flex;
  align-items: center;
  gap: 12px;
}

.section-title::before {
  content: '';
  width: 4px;
  height: 24px;
  background: var(--accent);
  border-radius: 2px;
}

/* Posts Grid */
.posts-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(300px, 1fr));
  gap: 24px;
}

.post-card {
  background: var(--bg-card);
  border: 1px solid var(--border-color);
  border-radius: 16px;
  padding: 24px;
  transition: all 0.3s;
  cursor: pointer;
  text-decoration: none;
  display: block;
}

.post-card:hover {
  border-color: var(--accent);
  transform: translateY(-4px);
  box-shadow: var(--shadow-lg);
}

.post-card-header {
  display: flex;
  align-items: flex-start;
  justify-content: space-between;
  margin-bottom: 12px;
}

.post-date {
  font-size: 0.85rem;
  color: var(--text-muted);
}

.post-badge {
  padding: 4px 10px;
  background: var(--accent-light);
  color: var(--accent);
  border-radius: 20px;
  font-size: 0.75rem;
  font-weight: 500;
}

.post-card h3 {
  font-size: 1.25rem;
  font-weight: 600;
  color: var(--text-primary);
  margin-bottom: 12px;
}

.post-card p {
  color: var(--text-secondary);
  font-size: 0.95rem;
  display: -webkit-box;
  -webkit-line-clamp: 3;
  -webkit-box-orient: vertical;
  overflow: hidden;
}

/* Tags */
.tags {
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
  margin-top: 16px;
}

.tag {
  padding: 4px 12px;
  background: var(--bg-secondary);
  color: var(--text-secondary);
  border-radius: 6px;
  font-size: 0.85rem;
}

/* About Section */
.about-section {
  background: var(--bg-secondary);
}

.about-content {
  display: flex;
  gap: 40px;
  align-items: center;
}

.about-avatar {
  width: 120px;
  height: 120px;
  background: linear-gradient(135deg, var(--accent), #8b5cf6);
  border-radius: 50%;
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 3rem;
  color: white;
  flex-shrink: 0;
}

.about-text h3 {
  font-size: 1.5rem;
  margin-bottom: 12px;
}

.about-text p {
  color: var(--text-secondary);
}

/* Post Page */
.post-page {
  padding: 40px 0;
}

.post-header {
  margin-bottom: 40px;
}

.post-meta {
  display: flex;
  gap: 16px;
  align-items: center;
  margin-bottom: 16px;
}

.post-meta .badge {
  padding: 4px 12px;
  background: var(--accent-light);
  color: var(--accent);
  border-radius: 20px;
  font-size: 0.85rem;
  font-weight: 500;
}

.post-meta .date {
  color: var(--text-muted);
  font-size: 0.9rem;
}

.post-title {
  font-size: 2.5rem;
  font-weight: 700;
  line-height: 1.2;
  margin-bottom: 16px;
}

.post-excerpt {
  font-size: 1.1rem;
  color: var(--text-secondary);
}

.post-content {
  font-size: 1.05rem;
  line-height: 1.8;
  color: var(--text-primary);
}

.post-content h2 {
  font-size: 1.75rem;
  font-weight: 600;
  margin: 40px 0 20px;
  padding-top: 40px;
}

.post-content h3 {
  font-size: 1.4rem;
  font-weight: 600;
  margin: 32px 0 16px;
}

.post-content p {
  margin-bottom: 16px;
}

.post-content ul, .post-content ol {
  margin-left: 24px;
  margin-bottom: 20px;
}

.post-content li {
  margin-bottom: 8px;
}

.post-content code {
  background: var(--bg-secondary);
  padding: 2px 8px;
  border-radius: 4px;
  font-size: 0.9em;
  font-family: 'Monaco', 'Menlo', monospace;
}

.post-content pre {
  background: var(--bg-secondary);
  padding: 16px;
  border-radius: 8px;
  overflow-x: auto;
  margin-bottom: 20px;
}

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

.post-content blockquote {
  border-left: 4px solid var(--accent);
  padding-left: 16px;
  margin: 20px 0;
  color: var(--text-secondary);
  font-style: italic;
}

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

.post-content a:hover {
  text-decoration: underline;
}

.post-content img {
  max-width: 100%;
  border-radius: 8px;
  margin: 24px 0;
}

/* Post Navigation */
.post-nav {
  display: flex;
  justify-content: space-between;
  gap: 20px;
  margin-top: 60px;
  padding-top: 40px;
  border-top: 1px solid var(--border-color);
}

.post-nav a {
  flex: 1;
  padding: 20px;
  background: var(--bg-secondary);
  border-radius: 12px;
  text-decoration: none;
  color: var(--text-primary);
  transition: all 0.3s;
}

.post-nav a:hover {
  background: var(--border-color);
}

.post-nav-label {
  font-size: 0.85rem;
  color: var(--text-muted);
  margin-bottom: 4px;
}

.post-nav-title {
  font-weight: 600;
}

.post-nav.prev .post-nav-title {
  text-align: left;
}

.post-nav.next .post-nav-title {
  text-align: right;
}

/* Back Button */
.back-btn {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  padding: 10px 20px;
  background: var(--bg-secondary);
  color: var(--text-primary);
  text-decoration: none;
  border-radius: 10px;
  margin-bottom: 32px;
  transition: all 0.3s;
}

.back-btn:hover {
  background: var(--border-color);
}

/* Footer */
footer {
  border-top: 1px solid var(--border-color);
  padding: 40px 0;
  margin-top: 60px;
}

.footer-content {
  display: flex;
  justify-content: space-between;
  align-items: center;
}

.footer-links {
  display: flex;
  gap: 24px;
}

.footer-links a {
  color: var(--text-secondary);
  text-decoration: none;
  transition: color 0.2s;
}

.footer-links a:hover {
  color: var(--accent);
}

.footer-copyright {
  color: var(--text-muted);
  font-size: 0.9rem;
}

/* Responsive */
@media (max-width: 768px) {
  .hero h1 {
    font-size: 2rem;
  }

  .hero p {
    font-size: 1rem;
  }

  .about-content {
    flex-direction: column;
    text-align: center;
  }

  .footer-content {
    flex-direction: column;
    gap: 16px;
    text-align: center;
  }

  .hero-links {
    flex-direction: column;
  }

  .posts-grid {
    grid-template-columns: 1fr;
  }

  .post-title {
    font-size: 1.75rem;
  }

  .post-nav {
    flex-direction: column;
  }
}

/* Animation */
@keyframes fadeInUp {
  from {
    opacity: 0;
    transform: translateY(20px);
  }
  to {
    opacity: 1;
    transform: translateY(0);
  }
}

.post-card {
  animation: fadeInUp 0.5s ease-out;
}

.post-card:nth-child(2) { animation-delay: 0.1s; }
.post-card:nth-child(3) { animation-delay: 0.2s; }
.post-card:nth-child(4) { animation-delay: 0.3s; }