/*
 * Ion Mudreac's Blog - Design System
 * Dark theme, professional aesthetic
 * Typography: Inter (body), JetBrains Mono (code)
 * Color palette: GitHub Dark-inspired
 */

/* CSS Custom Properties */
:root {
  /* Colors - GitHub Dark style */
  --bg-primary: #0d1117;
  --bg-secondary: #161b22;
  --bg-tertiary: #1c2128;
  --bg-code: #1c2128;
  
  --text-primary: #e6edf3;
  --text-secondary: #8b949e;
  --text-muted: #6e7681;
  
  --border-default: #30363d;
  --border-muted: #21262d;
  
  --accent-primary: #58a6ff;
  --accent-hover: #79c0ff;
  --accent-subtle: rgba(88, 166, 255, 0.1);
  
  --success: #3fb950;
  --warning: #d29922;
  --danger: #f85149;
  
  /* Typography */
  --font-sans: -apple-system, BlinkMacSystemFont, 'Segoe UI', 'Noto Sans', Helvetica, Arial, sans-serif;
  --font-mono: ui-monospace, 'Cascadia Code', 'Source Code Pro', Menlo, Consolas, 'DejaVu Sans Mono', monospace;
  
  /* Spacing scale */
  --space-1: 0.25rem;
  --space-2: 0.5rem;
  --space-3: 0.75rem;
  --space-4: 1rem;
  --space-5: 1.25rem;
  --space-6: 1.5rem;
  --space-8: 2rem;
  --space-10: 2.5rem;
  --space-12: 3rem;
  --space-16: 4rem;
  --space-20: 5rem;
  
  /* Layout */
  --content-width: 740px;
  --header-height: 64px;
  
  /* Border radius */
  --radius-sm: 4px;
  --radius-md: 6px;
  --radius-lg: 8px;
  --radius-xl: 12px;
  
  /* Shadows */
  --shadow-sm: 0 1px 2px rgba(0, 0, 0, 0.3);
  --shadow-md: 0 4px 6px -1px rgba(0, 0, 0, 0.4), 0 2px 4px -1px rgba(0, 0, 0, 0.2);
  --shadow-lg: 0 10px 15px -3px rgba(0, 0, 0, 0.5), 0 4px 6px -2px rgba(0, 0, 0, 0.3);
  --shadow-glow: 0 0 20px rgba(88, 166, 255, 0.15);
  
  /* Transitions */
  --transition-fast: 150ms ease;
  --transition-base: 250ms ease;
}

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

html {
  scroll-behavior: smooth;
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
}

body {
  font-family: var(--font-sans);
  font-size: 16px;
  line-height: 1.7;
  color: var(--text-primary);
  background-color: var(--bg-primary);
  min-height: 100vh;
}

/* Selection */
::selection {
  background-color: var(--accent-primary);
  color: var(--bg-primary);
}

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

a:hover {
  color: var(--accent-hover);
  text-decoration: underline;
  text-underline-offset: 3px;
}

/* Header */
.site-header {
  position: sticky;
  top: 0;
  z-index: 100;
  background-color: rgba(13, 17, 23, 0.95);
  backdrop-filter: blur(10px);
  border-bottom: 1px solid var(--border-muted);
}

.header-inner {
  max-width: var(--content-width);
  margin: 0 auto;
  padding: 0 var(--space-5);
  height: var(--header-height);
  display: flex;
  align-items: center;
  justify-content: space-between;
}

.site-brand {
  display: flex;
  flex-direction: column;
  gap: var(--space-1);
}

.site-name {
  font-size: 1.125rem;
  font-weight: 600;
  color: var(--text-primary);
  letter-spacing: -0.01em;
}

.site-name:hover {
  text-decoration: none;
  color: var(--accent-primary);
}

.site-tagline {
  font-size: 0.75rem;
  color: var(--text-secondary);
  font-weight: 400;
}

.site-nav {
  display: flex;
  gap: var(--space-6);
}

.site-nav a {
  font-size: 0.875rem;
  font-weight: 500;
  color: var(--text-secondary);
  transition: color var(--transition-fast);
}

.site-nav a:hover {
  color: var(--text-primary);
  text-decoration: none;
}

/* Main Layout */
main {
  max-width: var(--content-width);
  margin: 0 auto;
  padding: var(--space-12) var(--space-5) var(--space-20);
  animation: fadeIn 0.5s ease;
}

@keyframes fadeIn {
  from { opacity: 0; transform: translateY(10px); }
  to { opacity: 1; transform: translateY(0); }
}

/* Page Title */
.page-title {
  font-size: 2rem;
  font-weight: 700;
  margin-bottom: var(--space-2);
  letter-spacing: -0.02em;
}

.page-subtitle {
  color: var(--text-secondary);
  font-size: 1rem;
  margin-bottom: var(--space-10);
}

/* Post Cards */
.post-list {
  display: flex;
  flex-direction: column;
  gap: var(--space-6);
}

.post-card {
  display: block;
  padding: var(--space-6);
  background-color: var(--bg-secondary);
  border: 1px solid var(--border-muted);
  border-radius: var(--radius-lg);
  transition: all var(--transition-base);
}

.post-card:hover {
  transform: translateY(-2px);
  box-shadow: var(--shadow-lg), var(--shadow-glow);
  border-color: var(--border-default);
  text-decoration: none;
}

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

.post-card-header {
  display: flex;
  align-items: flex-start;
  justify-content: space-between;
  gap: var(--space-4);
  margin-bottom: var(--space-3);
}

.post-card-title {
  font-size: 1.25rem;
  font-weight: 600;
  color: var(--text-primary);
  line-height: 1.4;
  transition: color var(--transition-fast);
}

.post-card-meta {
  display: flex;
  align-items: center;
  gap: var(--space-3);
  font-size: 0.8125rem;
  color: var(--text-secondary);
  margin-bottom: var(--space-3);
}

.post-card-meta time {
  font-variant-numeric: tabular-nums;
}

.post-card-excerpt {
  color: var(--text-secondary);
  font-size: 0.9375rem;
  line-height: 1.6;
}

.post-card-tags {
  display: flex;
  gap: var(--space-2);
  margin-top: var(--space-4);
}

.tag {
  display: inline-flex;
  align-items: center;
  padding: var(--space-1) var(--space-3);
  font-size: 0.75rem;
  font-weight: 500;
  color: var(--accent-primary);
  background-color: var(--accent-subtle);
  border-radius: var(--radius-sm);
  text-transform: lowercase;
}

/* Article / Post Page */
.article-header {
  margin-bottom: var(--space-10);
  padding-bottom: var(--space-8);
  border-bottom: 1px solid var(--border-muted);
}

.article-title {
  font-size: 2.25rem;
  font-weight: 700;
  line-height: 1.2;
  margin-bottom: var(--space-5);
  letter-spacing: -0.02em;
}

.article-meta {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: var(--space-4);
  font-size: 0.875rem;
  color: var(--text-secondary);
}

.article-meta time {
  font-variant-numeric: tabular-nums;
}

.article-tags {
  display: flex;
  gap: var(--space-2);
}

/* Article Content */
.article-content {
  font-size: 1.0625rem;
  line-height: 1.8;
  color: var(--text-primary);
}

.article-content > * + * {
  margin-top: var(--space-6);
}

.article-content h1,
.article-content h2,
.article-content h3,
.article-content h4 {
  font-weight: 600;
  line-height: 1.3;
  margin-top: var(--space-12);
  margin-bottom: var(--space-4);
  letter-spacing: -0.01em;
}

.article-content h1 {
  font-size: 1.75rem;
}

.article-content h2 {
  font-size: 1.5rem;
  padding-bottom: var(--space-3);
  border-bottom: 1px solid var(--border-muted);
}

.article-content h3 {
  font-size: 1.25rem;
}

.article-content h4 {
  font-size: 1.125rem;
}

.article-content p {
  margin-bottom: var(--space-5);
}

.article-content a {
  text-decoration: underline;
  text-underline-offset: 3px;
}

.article-content ul,
.article-content ol {
  padding-left: var(--space-6);
  margin-bottom: var(--space-5);
}

.article-content li {
  margin-bottom: var(--space-2);
}

.article-content li > ul,
.article-content li > ol {
  margin-top: var(--space-2);
}

.article-content strong {
  font-weight: 600;
  color: var(--text-primary);
}

.article-content code {
  font-family: var(--font-mono);
  font-size: 0.875em;
  padding: var(--space-1) var(--space-2);
  background-color: var(--bg-code);
  border-radius: var(--radius-sm);
  color: var(--text-primary);
}

.article-content pre {
  font-family: var(--font-mono);
  font-size: 0.875rem;
  line-height: 1.6;
  background-color: var(--bg-code);
  padding: var(--space-5);
  border-radius: var(--radius-lg);
  overflow-x: auto;
  border: 1px solid var(--border-muted);
}

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

.article-content blockquote {
  padding: var(--space-4) var(--space-5);
  border-left: 4px solid var(--accent-primary);
  background-color: var(--bg-secondary);
  border-radius: 0 var(--radius-md) var(--radius-md) 0;
  margin: var(--space-6) 0;
  color: var(--text-secondary);
}

.article-content blockquote p:last-child {
  margin-bottom: 0;
}

.article-content hr {
  border: none;
  height: 1px;
  background: linear-gradient(to right, transparent, var(--border-default), transparent);
  margin: var(--space-12) 0;
}

.article-content table {
  width: 100%;
  border-collapse: collapse;
  font-size: 0.9375rem;
  margin: var(--space-6) 0;
}

.article-content th,
.article-content td {
  padding: var(--space-3) var(--space-4);
  text-align: left;
  border: 1px solid var(--border-default);
}

.article-content th {
  background-color: var(--bg-secondary);
  font-weight: 600;
}

.article-content tr:nth-child(even) {
  background-color: var(--bg-secondary);
}

/* Table of Contents */
.toc {
  background-color: var(--bg-secondary);
  border: 1px solid var(--border-muted);
  border-radius: var(--radius-lg);
  padding: var(--space-5);
  margin: var(--space-8) 0;
}

.toc-title {
  font-size: 0.875rem;
  font-weight: 600;
  text-transform: uppercase;
  letter-spacing: 0.05em;
  color: var(--text-secondary);
  margin-bottom: var(--space-4);
}

.toc ul {
  list-style: none;
  padding: 0;
  margin: 0;
}

.toc li {
  margin-bottom: var(--space-2);
}

.toc a {
  font-size: 0.9375rem;
  color: var(--text-secondary);
  text-decoration: none;
  display: block;
  padding: var(--space-1) 0;
  transition: color var(--transition-fast);
}

.toc a:hover {
  color: var(--accent-primary);
}

.toc-h3 {
  padding-left: var(--space-4);
}

/* Post Navigation */
.post-nav {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: var(--space-6);
  margin-top: var(--space-16);
  padding-top: var(--space-8);
  border-top: 1px solid var(--border-muted);
}

.post-nav-item {
  padding: var(--space-5);
  background-color: var(--bg-secondary);
  border: 1px solid var(--border-muted);
  border-radius: var(--radius-lg);
  transition: all var(--transition-base);
}

.post-nav-item:hover {
  border-color: var(--border-default);
  box-shadow: var(--shadow-md);
  text-decoration: none;
}

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

.post-nav-item.next {
  text-align: right;
  grid-column: 2;
}

.post-nav-item:only-child {
  grid-column: 1;
}

.post-nav-label {
  font-size: 0.75rem;
  text-transform: uppercase;
  letter-spacing: 0.05em;
  color: var(--text-muted);
  margin-bottom: var(--space-2);
}

.post-nav-title {
  font-size: 1rem;
  font-weight: 600;
  color: var(--text-primary);
}

/* Share Section */
.share-section {
  display: flex;
  align-items: center;
  gap: var(--space-4);
  margin-top: var(--space-8);
  padding: var(--space-4) 0;
}

.share-label {
  font-size: 0.875rem;
  color: var(--text-secondary);
}

.btn-copy {
  display: inline-flex;
  align-items: center;
  gap: var(--space-2);
  padding: var(--space-2) var(--space-4);
  font-size: 0.8125rem;
  font-weight: 500;
  color: var(--text-secondary);
  background-color: var(--bg-secondary);
  border: 1px solid var(--border-muted);
  border-radius: var(--radius-md);
  cursor: pointer;
  transition: all var(--transition-fast);
}

.btn-copy:hover {
  background-color: var(--bg-tertiary);
  border-color: var(--border-default);
  color: var(--text-primary);
}

.btn-copy.copied {
  color: var(--success);
  border-color: var(--success);
}

/* Comments Section */
.comments-section {
  margin-top: var(--space-16);
  padding-top: var(--space-8);
  border-top: 1px solid var(--border-muted);
}

.comments-title {
  font-size: 1.25rem;
  font-weight: 600;
  margin-bottom: var(--space-6);
}

.comment-form {
  background-color: var(--bg-secondary);
  border: 1px solid var(--border-muted);
  border-radius: var(--radius-lg);
  padding: var(--space-6);
  margin-bottom: var(--space-8);
}

.form-group {
  margin-bottom: var(--space-5);
}

.form-group:last-child {
  margin-bottom: 0;
}

.form-label {
  display: block;
  font-size: 0.875rem;
  font-weight: 500;
  color: var(--text-secondary);
  margin-bottom: var(--space-2);
}

.form-input,
.form-textarea {
  width: 100%;
  padding: var(--space-3) var(--space-4);
  font-size: 0.9375rem;
  font-family: var(--font-sans);
  color: var(--text-primary);
  background-color: var(--bg-primary);
  border: 1px solid var(--border-default);
  border-radius: var(--radius-md);
  transition: border-color var(--transition-fast), box-shadow var(--transition-fast);
}

.form-input:focus,
.form-textarea:focus {
  outline: none;
  border-color: var(--accent-primary);
  box-shadow: 0 0 0 3px var(--accent-subtle);
}

.form-textarea {
  min-height: 120px;
  resize: vertical;
  line-height: 1.6;
}

.form-footer {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: var(--space-4);
}

.char-counter {
  font-size: 0.8125rem;
  color: var(--text-muted);
}

.char-counter.near-limit {
  color: var(--warning);
}

.char-counter.at-limit {
  color: var(--danger);
}

.btn-submit {
  display: inline-flex;
  align-items: center;
  gap: var(--space-2);
  padding: var(--space-3) var(--space-6);
  font-size: 0.9375rem;
  font-weight: 500;
  color: var(--bg-primary);
  background-color: var(--accent-primary);
  border: none;
  border-radius: var(--radius-md);
  cursor: pointer;
  transition: background-color var(--transition-fast);
}

.btn-submit:hover {
  background-color: var(--accent-hover);
}

.btn-submit:disabled {
  opacity: 0.6;
  cursor: not-allowed;
}

/* Honeypot field */
.honeypot {
  position: absolute;
  left: -9999px;
  opacity: 0;
}

/* Comments List */
.comments-list {
  display: flex;
  flex-direction: column;
  gap: var(--space-5);
}

.comment {
  background-color: var(--bg-secondary);
  border: 1px solid var(--border-muted);
  border-radius: var(--radius-lg);
  padding: var(--space-5);
  animation: commentFadeIn 0.3s ease;
}

@keyframes commentFadeIn {
  from { opacity: 0; transform: translateY(10px); }
  to { opacity: 1; transform: translateY(0); }
}

.comment-header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: var(--space-4);
  margin-bottom: var(--space-3);
}

.comment-author {
  font-weight: 600;
  color: var(--accent-primary);
}

.comment-time {
  font-size: 0.8125rem;
  color: var(--text-muted);
}

.comment-content {
  color: var(--text-secondary);
  line-height: 1.6;
}

.comment-content p {
  margin-bottom: var(--space-3);
}

.comment-content p:last-child {
  margin-bottom: 0;
}

.comments-empty {
  text-align: center;
  padding: var(--space-10);
  color: var(--text-muted);
}

/* Alerts */
.alert {
  padding: var(--space-4) var(--space-5);
  border-radius: var(--radius-md);
  margin-bottom: var(--space-5);
}

.alert-success {
  background-color: rgba(63, 185, 80, 0.1);
  border: 1px solid rgba(63, 185, 80, 0.3);
  color: var(--success);
}

.alert-error {
  background-color: rgba(248, 81, 73, 0.1);
  border: 1px solid rgba(248, 81, 73, 0.3);
  color: var(--danger);
}

/* Loading state */
.loading {
  display: flex;
  align-items: center;
  justify-content: center;
  padding: var(--space-10);
  color: var(--text-muted);
}

.spinner {
  width: 24px;
  height: 24px;
  border: 2px solid var(--border-default);
  border-top-color: var(--accent-primary);
  border-radius: 50%;
  animation: spin 0.8s linear infinite;
  margin-right: var(--space-3);
}

@keyframes spin {
  to { transform: rotate(360deg); }
}

/* Footer */
.site-footer {
  border-top: 1px solid var(--border-muted);
  padding: var(--space-10) var(--space-5);
  margin-top: auto;
}

.footer-inner {
  max-width: var(--content-width);
  margin: 0 auto;
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: var(--space-5);
}

.footer-links {
  display: flex;
  gap: var(--space-6);
}

.footer-links a {
  font-size: 0.875rem;
  color: var(--text-secondary);
}

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

.footer-copyright {
  font-size: 0.8125rem;
  color: var(--text-muted);
}

/* Error Page */
.error-container {
  text-align: center;
  padding: var(--space-20) var(--space-5);
}

.error-code {
  font-size: 6rem;
  font-weight: 700;
  color: var(--accent-primary);
  line-height: 1;
  margin-bottom: var(--space-4);
}

.error-message {
  font-size: 1.25rem;
  color: var(--text-secondary);
  margin-bottom: var(--space-8);
}

/* Responsive */
@media (max-width: 640px) {
  :root {
    --content-width: 100%;
  }
  
  .header-inner {
    padding: 0 var(--space-4);
  }
  
  .site-tagline {
    display: none;
  }
  
  main {
    padding: var(--space-8) var(--space-4) var(--space-16);
  }
  
  .article-title {
    font-size: 1.75rem;
  }
  
  .article-content {
    font-size: 1rem;
  }
  
  .article-content h1 {
    font-size: 1.5rem;
  }
  
  .article-content h2 {
    font-size: 1.25rem;
  }
  
  .post-card {
    padding: var(--space-5);
  }
  
  .post-nav {
    grid-template-columns: 1fr;
  }
  
  .post-nav-item.next {
    grid-column: 1;
    text-align: left;
  }
  
  .form-footer {
    flex-direction: column;
    align-items: stretch;
  }
  
  .btn-submit {
    width: 100%;
    justify-content: center;
  }
}

/* Print styles */
@media print {
  .site-header,
  .comments-section,
  .post-nav,
  .share-section,
  .site-footer {
    display: none;
  }
  
  body {
    background: white;
    color: black;
  }
  
  .article-content a {
    color: black;
    text-decoration: underline;
  }
  
  .article-content a::after {
    content: " (" attr(href) ")";
    font-size: 0.8em;
  }
}