/* ========================================
   Design Tokens (from guideline)
   ======================================== */

:root {
  /* Colors */
  --color-bg: #09090B;
  --color-bg-elevated: #111113;
  --color-bg-hover: #18181B;
  --color-surface: #1C1C1F;

  --color-text: #FAFAFA;
  --color-text-secondary: #A1A1AA;
  --color-text-muted: #52525B;

  --color-accent: #10B981;
  --color-accent-dim: rgba(16, 185, 129, 0.15);

  --color-border: #27272A;
  --color-border-subtle: #1F1F23;

  /* Typography */
  --font-sans: 'IBM Plex Sans', -apple-system, sans-serif;
  --font-mono: 'IBM Plex Mono', 'SF Mono', monospace;

  /* Spacing (8px scale) */
  --space-unit: 8px;
  --space-1: calc(var(--space-unit) * 1);   /* 8px */
  --space-2: calc(var(--space-unit) * 2);   /* 16px */
  --space-3: calc(var(--space-unit) * 3);   /* 24px */
  --space-4: calc(var(--space-unit) * 4);   /* 32px */
  --space-6: calc(var(--space-unit) * 6);   /* 48px */
  --space-8: calc(var(--space-unit) * 8);   /* 64px */
  --space-12: calc(var(--space-unit) * 12); /* 96px */
  --space-16: calc(var(--space-unit) * 16); /* 128px */
  --space-24: calc(var(--space-unit) * 24); /* 192px */

  /* Container sizes */
  --page-max: 1200px;
  --page-padding: max(24px, 5vw);
  --content-max: 1000px;
}

/* ========================================
   Global Reset & Base Styles
   ======================================== */

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

html {
  font-size: 16px;
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
}

body {
  font-family: var(--font-sans);
  font-size: 1rem;
  line-height: 1.6;
  color: var(--color-text);
  background: var(--color-bg);
  min-height: 100vh;
  position: relative;
}

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

strong {
  font-weight: 600;
  color: var(--color-text);
}

a {
  color: inherit;
  text-decoration: none;
}

::selection {
  background: var(--color-accent);
  color: var(--color-bg);
}

a:focus-visible {
  outline: 2px solid var(--color-accent);
  outline-offset: 2px;
}

/* ========================================
   Grain Texture Overlay
   ======================================== */

.grain {
  position: fixed;
  inset: 0;
  pointer-events: none;
  opacity: 0.03;
  z-index: 1000;
  background-image: url("data:image/svg+xml,%3Csvg viewBox='0 0 400 400' xmlns='http://www.w3.org/2000/svg'%3E%3Cfilter id='noiseFilter'%3E%3CfeTurbulence type='fractalNoise' baseFrequency='0.9' numOctaves='4' stitchTiles='stitch'/%3E%3C/filter%3E%3Crect width='100%25' height='100%25' filter='url(%23noiseFilter)'/%3E%3C/svg%3E");
}

/* ========================================
   Header (Fixed)
   ======================================== */

.site-header {
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  background: rgba(9, 9, 11, 0.8);
  backdrop-filter: blur(12px);
  border-bottom: 1px solid var(--color-border-subtle);
  z-index: 100;
}

.header-content {
  max-width: calc(var(--page-max) + var(--page-padding) * 2);
  margin: 0 auto;
  padding: var(--space-2) var(--page-padding);
  display: flex;
  align-items: center;
  justify-content: space-between;
}

.header-left {
    display: flex;
    align-items: center;
}

@media (max-width: 900px) {
  .site-header {
    position: relative;
  }
  
  .header-content {
    padding: var(--space-2) var(--space-3);
  }
  
  .site-logo {
    font-size: 1rem;
  }
  
  .status-text {
    display: none;
  }
}

.site-logo {
  font-size: 1.125rem;
  font-weight: 600;
  letter-spacing: -0.02em;
  color: var(--color-text);
  transition: color 0.2s ease;
}

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

@media (max-width: 900px) {
  .site-header {
    position: relative;
  }
  
  .header-content {
    padding: var(--space-2) var(--space-3);
  }
  
  .site-logo {
    font-size: 1rem;
  }
}

.status-indicator {
  display: flex;
  align-items: center;
  gap: var(--space-1);
  font-family: var(--font-mono);
  font-size: 0.75rem;
  color: var(--color-text-muted);
  text-transform: uppercase;
  letter-spacing: 0.1em;
}

@media (max-width: 600px) {
  .status-indicator {
    font-size: 0;
  }
  
  .status-indicator .status-dot {
    margin: 0;
  }
}

.status-dot {
  width: 8px;
  height: 8px;
  border-radius: 50%;
  background: var(--color-accent);
  animation: pulse 2s ease-in-out infinite;
}

@keyframes pulse {
  0%, 100% { opacity: 1; }
  50% { opacity: 0.5; }
}

/* Mobile Menu Button */
.mobile-menu-btn {
  display: none;
  flex-direction: column;
  gap: 4px;
  background: transparent;
  border: none;
  cursor: pointer;
  padding: var(--space-1);
  margin-right: var(--space-2);
}

.mobile-menu-btn span {
  display: block;
  width: 20px;
  height: 2px;
  background: var(--color-text);
  transition: all 0.3s ease;
}

.mobile-menu-btn.open span:nth-child(1) {
  transform: rotate(45deg) translate(5px, 5px);
}

.mobile-menu-btn.open span:nth-child(2) {
  opacity: 0;
}

.mobile-menu-btn.open span:nth-child(3) {
  transform: rotate(-45deg) translate(6px, -6px);
}

.mobile-overlay {
  display: none;
  position: fixed;
  inset: 0;
  background: rgba(9, 9, 11, 0.8);
  z-index: 150;
}

.mobile-overlay.visible {
  display: block;
}

@media (max-width: 900px) {
  .mobile-menu-btn {
    display: flex;
  }
}

/* ========================================
   Layout (Sidebar + Main)
   ======================================== */

.layout {
  display: grid;
  grid-template-columns: 280px 1fr;
  max-width: calc(var(--page-max) + var(--page-padding) * 2);
  margin: 0 auto;
  padding-top: calc(var(--space-8) + var(--space-2)); /* header height */
}

@media (max-width: 900px) {
  .layout {
    display: block;
    padding-top: calc(var(--space-6) + var(--space-2));
  }
  
  .sidebar {
    position: fixed;
    top: 0;
    left: -100%;
    width: 280px;
    height: 100vh;
    background: var(--color-bg);
    border-right: 1px solid var(--color-border);
    z-index: 200;
    transition: left 0.3s ease;
    padding: calc(var(--space-6) + var(--space-4)) var(--space-3) var(--space-3);
  }
  
  .sidebar.open {
    left: 0;
  }
  
  .sidebar-section {
    margin-bottom: var(--space-4);
  }
  
  .anchor-text {
    padding-left: 0;
    margin-left: var(--space-1);
  }
}

/* ========================================
   Sidebar Navigation
   ======================================== */

.sidebar {
  position: sticky;
  top: calc(var(--space-8) + var(--space-2));
  height: calc(100vh - var(--space-8) - var(--space-2));
  overflow-y: auto;
  padding: var(--space-4) var(--space-3);
  border-right: 1px solid var(--color-border);
}

@media (max-width: 900px) {
  .sidebar {
    position: fixed;
    top: 0;
    left: -100%;
    width: 280px;
    height: 100vh;
    background: var(--color-bg);
    border-right: 1px solid var(--color-border);
    z-index: 200;
    transition: left 0.3s ease;
    padding-top: calc(var(--space-6) + var(--space-2));
  }
  
  .sidebar.open {
    left: 0;
  }
}

.sidebar-section {
  margin-bottom: var(--space-6);
}

.anchor-wrapper {
  margin-bottom: var(--space-3);
}

.anchor-line {
  width: 32px;
  height: 1px;
  background: var(--color-accent);
  margin-bottom: var(--space-1);
}

.anchor-text {
  font-family: var(--font-mono);
  font-size: 0.75rem;
  font-weight: 500;
  color: var(--color-text-muted);
  text-transform: uppercase;
  letter-spacing: 0.1em;
  padding-left: 44px;
}

.nav-list {
  list-style: none;
}

.nav-item {
  margin-bottom: 2px;
}

.nav-link {
  display: block;
  padding: var(--space-1) var(--space-2);
  border-radius: 6px;
  color: var(--color-text-secondary);
  font-size: 0.875rem;
  transition: all 0.2s ease;
  border: 1px solid transparent;
}

.nav-link:hover {
  background: var(--color-bg-hover);
  color: var(--color-text);
  border-color: var(--color-border);
}

.nav-link.active {
  background: var(--color-bg-elevated);
  color: var(--color-text);
  font-weight: 500;
  border-color: var(--color-accent);
}

/* Scrollbar for sidebar */
.sidebar::-webkit-scrollbar {
  width: 6px;
}

.sidebar::-webkit-scrollbar-track {
  background: transparent;
}

.sidebar::-webkit-scrollbar-thumb {
  background: var(--color-border);
  border-radius: 3px;
}

.sidebar::-webkit-scrollbar-thumb:hover {
  background: var(--color-text-muted);
}

/* ========================================
   Main Content
   ======================================== */

.main-content {
  padding: var(--space-6) var(--page-padding);
  min-height: calc(100vh - var(--space-8) - var(--space-2));
}

@media (max-width: 900px) {
  .main-content {
    padding: var(--space-4) var(--space-3);
    min-height: auto;
  }
}

/* ========================================
   Typography Hierarchy
   ======================================== */

h1, h2, h3 {
  font-weight: 600;
  line-height: 1.2;
  letter-spacing: -0.02em;
  color: var(--color-text);
}

h1 {
  font-size: clamp(2rem, 5vw, 3.25rem);
  letter-spacing: -0.03em;
  margin-bottom: var(--space-3);
}

h2 {
  font-size: clamp(1.5rem, 3vw, 2rem);
  margin: var(--space-6) 0 var(--space-3);
}

h3 {
  font-size: 1.125rem;
  margin: var(--space-4) 0 var(--space-2);
}

/* ========================================
   Article Content Styles
   ======================================== */

.article-wrapper {
  max-width: var(--content-max);
}

.article-header {
  margin-bottom: var(--space-6);
  padding-bottom: var(--space-4);
  border-bottom: 1px solid var(--color-border);
}

.article-title {
  font-size: clamp(2rem, 4vw, 2.5rem);
  margin-bottom: var(--space-2);
}

.article-meta {
  font-family: var(--font-mono);
  font-size: 0.75rem;
  color: var(--color-text-muted);
  text-transform: uppercase;
  letter-spacing: 0.1em;
}

.translate-disclaimer {
  padding: var(--space-2);
  background: var(--color-bg-elevated);
  border: 1px solid var(--color-border);
  border-radius: 8px;
  margin-bottom: var(--space-4);
  font-size: 0.875rem;
}

.article-content p {
  margin-bottom: var(--space-3);
  line-height: 1.8;
}

.article-content a {
  color: var(--color-accent);
  border-bottom: 1px solid transparent;
  transition: border-color 0.2s ease;
}

.article-content a:hover {
  border-bottom-color: var(--color-accent);
}

.article-content ul,
.article-content ol {
  margin: var(--space-3) 0;
  padding-left: var(--space-4);
  color: var(--color-text-secondary);
}

.article-content li {
  margin-bottom: var(--space-1);
  line-height: 1.8;
}

.article-content code {
  font-family: var(--font-mono);
  font-size: 0.875em;
  background: var(--color-bg-elevated);
  color: var(--color-accent);
  padding: 0.2em 0.4em;
  border-radius: 4px;
  border: 1px solid var(--color-border);
}

.article-content pre {
  background: var(--color-bg-elevated);
  border: 1px solid var(--color-border);
  border-radius: 8px;
  padding: var(--space-3);
  margin: var(--space-4) 0;
  overflow-x: auto;
}

.article-content pre code {
  background: transparent;
  border: none;
  padding: 0;
  color: var(--color-text-secondary);
}

.article-content blockquote {
  border-left: 2px solid var(--color-border);
  padding-left: var(--space-3);
  margin: var(--space-4) 0;
  color: var(--color-text-muted);
  font-style: italic;
  background: transparent;
}

.article-content img {
  max-width: 100%;
  border-radius: 8px;
  margin: var(--space-4) 0;
  border: 1px solid var(--color-border);
}

/* ========================================
   Cards (for article list)
   ======================================== */

.articles-grid {
  display: grid;
  gap: var(--space-2);
  margin-top: var(--space-6);
}

.article-card {
  background: var(--color-bg-elevated);
  border: 1px solid var(--color-border);
  border-radius: 8px;
  padding: var(--space-3);
  position: relative;
  transition: all 0.25s ease;
}

@media (max-width: 600px) {
  .article-card {
    padding: var(--space-2);
  }
  
  .article-card h2 {
    font-size: 1rem;
  }
  
  .article-card:hover {
    transform: translateX(2px);
  }
}

.article-card::before {
  content: '';
  position: absolute;
  left: 0;
  top: 0;
  bottom: 0;
  width: 4px;
  background: linear-gradient(to bottom, var(--color-accent), transparent);
  border-radius: 8px 0 0 8px;
  opacity: 0;
  transition: opacity 0.25s ease;
}

.article-card:hover {
  background: var(--color-bg-hover);
  border-color: var(--color-accent);
  transform: translateX(4px);
}

.article-card:hover::before {
  opacity: 1;
}

.article-card h2 {
  margin: 0 0 var(--space-1) 0;
  font-size: 1.125rem;
}

.article-card h2 a {
  color: var(--color-text);
  transition: color 0.2s ease;
}

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

.article-card .original-link {
  margin: 0;
  font-size: 0.875rem;
  font-family: var(--font-mono);
}

.article-card .original-link a {
  color: var(--color-text-muted);
  border-bottom: 1px solid transparent;
  transition: all 0.2s ease;
}

.article-card .original-link a:hover {
  color: var(--color-text-secondary);
  border-bottom-color: var(--color-text-muted);
}

/* ========================================
   Share Section
   ======================================== */

.share-section {
  margin: var(--space-8) 0 var(--space-6);
  padding: var(--space-4);
  background: var(--color-bg-elevated);
  border: 1px solid var(--color-border);
  border-radius: 8px;
  max-width: var(--content-max);
}

.share-section h3 {
  margin: 0 0 var(--space-3) 0;
  font-size: 1.125rem;
}

.share-buttons {
  display: flex;
  flex-wrap: wrap;
  gap: var(--space-2);
}

.share-btn {
  display: inline-flex;
  align-items: center;
  gap: var(--space-1);
  padding: var(--space-1) var(--space-2);
  background: var(--color-bg);
  border: 1px solid var(--color-border);
  border-radius: 6px;
  color: var(--color-text-secondary);
  font-size: 0.875rem;
  font-family: var(--font-mono);
  transition: all 0.2s ease;
  cursor: pointer;
}

.share-btn:hover {
  background: var(--color-bg-hover);
  border-color: var(--color-accent);
  color: var(--color-text);
}

.share-btn svg {
  width: 18px;
  height: 18px;
  flex-shrink: 0;
}

.linkedin-share:hover {
  background: #0077b5;
  border-color: #0077b5;
  color: #ffffff;
}

.telegram-share:hover {
  background: #0088cc;
  border-color: #0088cc;
  color: #ffffff;
}

.email-share:hover {
  background: #ea4335;
  border-color: #ea4335;
  color: #ffffff;
}

.copy-link.copied {
  background: var(--color-accent);
  border-color: var(--color-accent);
  color: var(--color-bg);
}

@media (max-width: 768px) {
  .share-buttons {
    flex-direction: column;
  }
  
  .share-btn {
    width: 100%;
    justify-content: center;
  }
}

/* ========================================
   Footer
   ======================================== */

footer {
  background: var(--color-bg-elevated);
  border-top: 1px solid var(--color-border);
  padding: var(--space-6) var(--space-4);
  max-width: var(--content-max);
}

footer h3 {
  margin-bottom: var(--space-2);
  font-size: 1rem;
}

.small-paragraph {
  font-size: 0.875rem;
  margin-bottom: var(--space-2);
  color: var(--color-text-secondary);
  line-height: 1.6;
}

/* ========================================
   Intro Section (for homepage)
   ======================================== */

.intro-section {
  margin-bottom: var(--space-8);
  max-width: var(--content-max);
}

.intro-section h1 {
  margin-bottom: var(--space-3);
}

.intro-section p {
  margin-bottom: var(--space-3);
  line-height: 1.8;
}

.section-divider {
  margin: var(--space-8) 0;
  height: 1px;
  background: var(--color-border);
  max-width: var(--content-max);
}

/* ========================================
   Empty State Pattern
   ======================================== */

.empty-state {
  padding: var(--space-6);
  border: 1px dashed var(--color-border);
  border-radius: 6px;
  text-align: center;
  font-family: var(--font-mono);
  color: var(--color-text-muted);
  font-size: 0.875rem;
  text-transform: uppercase;
  letter-spacing: 0.1em;
}

/* ========================================
   Responsive Adjustments
   ======================================== */

@media (max-width: 768px) {
  .main-content {
    padding: var(--space-4) var(--space-3);
  }
  
  .article-content p {
    max-width: 100%;
  }
  
  .header-content {
    padding: var(--space-2) var(--space-3);
  }
  
  .intro-section {
    margin-bottom: var(--space-6);
  }
  
  .section-divider {
    margin: var(--space-6) 0;
  }
  
  h2 {
    margin: var(--space-4) 0 var(--space-2);
  }
  
  .article-header {
    margin-bottom: var(--space-4);
    padding-bottom: var(--space-3);
  }
}

@media (max-width: 600px) {
  .intro-section {
    margin-bottom: var(--space-4);
  }
  
  .article-list {
    gap: var(--space-2);
  }
  
  .empty-state {
    padding: var(--space-4);
    font-size: 0.75rem;
  }
  
  h1 {
    margin-bottom: var(--space-2);
  }
  
  h2 {
    margin: var(--space-3) 0 var(--space-2);
  }
  
  h3 {
    margin: var(--space-3) 0 var(--space-1);
  }
}

/* ========================================
   Accessibility
   ======================================== */

@media (prefers-reduced-motion: reduce) {
  *,
  *::before,
  *::after {
    animation-duration: 0.01ms !important;
    animation-iteration-count: 1 !important;
    transition-duration: 0.01ms !important;
  }
}