/* ==========================================================================
   XiaoqiangClub - Modern Markdown Article Styles
   Design: Modern Minimalist with Tech Aesthetics
   ========================================================================== */

/* CSS Variables - Design System */
:root {
  /* Color Palette - Deep Space Theme */
  --bg-primary: #0a0a0f;
  --bg-secondary: #12121a;
  --bg-tertiary: #1a1a25;
  --bg-card: rgba(255, 255, 255, 0.03);
  --bg-card-hover: rgba(255, 255, 255, 0.06);

  /* Accent Colors */
  --accent-primary: #6366f1;
  --accent-secondary: #8b5cf6;
  --accent-gradient: linear-gradient(
    135deg,
    #6366f1 0%,
    #8b5cf6 50%,
    #d946ef 100%
  );

  /* Text Colors */
  --text-primary: #f8fafc;
  --text-secondary: #94a3b8;
  --text-muted: #64748b;

  /* Functional Colors */
  --border-color: rgba(255, 255, 255, 0.08);
  --border-highlight: rgba(99, 102, 241, 0.3);
  --shadow-soft: 0 4px 24px rgba(0, 0, 0, 0.4);
  --shadow-glow: 0 0 40px rgba(99, 102, 241, 0.15);

  /* Typography */
  --font-display:
    "SF Pro Display", -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto,
    sans-serif;
  --font-body:
    "SF Pro Text", -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto,
    sans-serif;
  --font-mono: "SF Mono", "Fira Code", "Consolas", monospace;

  /* Spacing */
  --spacing-xs: 0.25rem;
  --spacing-sm: 0.5rem;
  --spacing-md: 1rem;
  --spacing-lg: 1.5rem;
  --spacing-xl: 2rem;
  --spacing-2xl: 3rem;
  --spacing-3xl: 4rem;

  /* Transitions */
  --transition-fast: 0.15s ease;
  --transition-normal: 0.3s cubic-bezier(0.4, 0, 0.2, 1);
  --transition-slow: 0.5s cubic-bezier(0.4, 0, 0.2, 1);

  /* Border Radius */
  --radius-sm: 6px;
  --radius-md: 12px;
  --radius-lg: 16px;
  --radius-xl: 24px;
  --radius-full: 9999px;
}

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

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

body {
  font-family: var(--font-body);
  background: var(--bg-primary);
  color: var(--text-primary);
  line-height: 1.8;
  min-height: 100vh;
  overflow-x: hidden;
}

/* Ambient Background Effects */
body::before {
  content: "";
  position: fixed;
  top: 0;
  left: 0;
  width: 100%;
  height: 100%;
  background:
    radial-gradient(
      ellipse 80% 50% at 50% -20%,
      rgba(99, 102, 241, 0.15),
      transparent
    ),
    radial-gradient(
      ellipse 60% 40% at 80% 60%,
      rgba(139, 92, 246, 0.08),
      transparent
    ),
    radial-gradient(
      ellipse 50% 30% at 20% 80%,
      rgba(217, 70, 239, 0.06),
      transparent
    );
  pointer-events: none;
  z-index: -1;
}

/* Typography */
h1,
h2,
h3,
h4,
h5,
h6 {
  font-family: var(--font-display);
  font-weight: 700;
  line-height: 1.3;
  color: var(--text-primary);
  margin-bottom: var(--spacing-lg);
}

h1 {
  font-size: 2.5rem;
  letter-spacing: -0.02em;
}
h2 {
  font-size: 2rem;
  letter-spacing: -0.01em;
}
h3 {
  font-size: 1.5rem;
}
h4 {
  font-size: 1.25rem;
}
h5 {
  font-size: 1.125rem;
}
h6 {
  font-size: 1rem;
}

p {
  margin-bottom: var(--spacing-lg);
  color: var(--text-secondary);
}

a {
  color: var(--accent-primary);
  text-decoration: none;
  transition: color var(--transition-fast);
  position: relative;
}

a:hover {
  color: var(--accent-secondary);
}

a::after {
  content: "";
  position: absolute;
  bottom: -2px;
  left: 0;
  width: 100%;
  height: 2px;
  background: var(--accent-gradient);
  transform: scaleX(0);
  transform-origin: right;
  transition: transform var(--transition-normal);
}

a:hover::after {
  transform: scaleX(1);
  transform-origin: left;
}

/* Code Blocks */
code {
  font-family: var(--font-mono);
  font-size: 0.875em;
  background: var(--bg-tertiary);
  padding: 0.2em 0.4em;
  border-radius: var(--radius-sm);
  border: 1px solid var(--border-color);
}

pre {
  background: var(--bg-secondary);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-md);
  padding: var(--spacing-lg);
  overflow-x: auto;
  margin-bottom: var(--spacing-xl);
  position: relative;
}

pre::before {
  content: "";
  position: absolute;
  top: 0;
  left: 0;
  right: 0;
  height: 3px;
  background: var(--accent-gradient);
  border-radius: var(--radius-md) var(--radius-md) 0 0;
}

pre code {
  background: none;
  padding: 0;
  border: none;
  font-size: 0.875rem;
  line-height: 1.7;
  color: #e2e8f0;
}

/* Blockquotes */
blockquote {
  border-left: 4px solid var(--accent-primary);
  padding-left: var(--spacing-lg);
  margin: var(--spacing-xl) 0;
  color: var(--text-secondary);
  font-style: italic;
  background: var(--bg-card);
  padding: var(--spacing-md) var(--spacing-lg);
  border-radius: 0 var(--radius-md) var(--radius-md) 0;
  position: relative;
}

blockquote::before {
  content: '"';
  position: absolute;
  top: -10px;
  left: 10px;
  font-size: 4rem;
  color: var(--accent-primary);
  opacity: 0.2;
  font-family: Georgia, serif;
}

/* Lists */
ul,
ol {
  margin-bottom: var(--spacing-lg);
  padding-left: var(--spacing-xl);
}

li {
  margin-bottom: var(--spacing-sm);
  color: var(--text-secondary);
}

li::marker {
  color: var(--accent-primary);
}

/* Tables */
table {
  width: 100%;
  border-collapse: collapse;
  margin: var(--spacing-xl) 0;
  background: var(--bg-card);
  border-radius: var(--radius-md);
  overflow: hidden;
}

th,
td {
  padding: var(--spacing-md) var(--spacing-lg);
  text-align: left;
  border-bottom: 1px solid var(--border-color);
}

th {
  background: var(--bg-tertiary);
  font-weight: 600;
  color: var(--text-primary);
  font-family: var(--font-display);
}

tr:hover td {
  background: var(--bg-card-hover);
}

tr:last-child td {
  border-bottom: none;
}

/* Images */
img {
  max-width: 100%;
  height: auto;
  border-radius: var(--radius-md);
  margin: var(--spacing-xl) 0;
  box-shadow: var(--shadow-soft);
  transition:
    transform var(--transition-normal),
    box-shadow var(--transition-normal);
}

img:hover {
  transform: translateY(-2px);
  box-shadow: var(--shadow-glow);
}

/* Horizontal Rule */
hr {
  border: none;
  height: 1px;
  background: linear-gradient(
    90deg,
    transparent,
    var(--accent-primary),
    transparent
  );
  margin: var(--spacing-3xl) 0;
  position: relative;
}

hr::before {
  content: "";
  position: absolute;
  top: 50%;
  left: 50%;
  transform: translate(-50%, -50%);
  width: 8px;
  height: 8px;
  background: var(--accent-gradient);
  border-radius: 50%;
  box-shadow: var(--shadow-glow);
}

/* Article Container */
.article-container {
  max-width: 800px;
  margin: 0 auto;
  padding: var(--spacing-3xl) var(--spacing-xl);
  position: relative;
}

/* Article Header */
.article-header {
  text-align: center;
  margin-bottom: var(--spacing-3xl);
  position: relative;
}

.article-title {
  font-size: 3rem;
  font-weight: 800;
  margin-bottom: var(--spacing-lg);
  background: var(--accent-gradient);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
  animation: titleGradient 8s ease infinite;
  background-size: 200% 200%;
}

@keyframes titleGradient {
  0%,
  100% {
    background-position: 0% 50%;
  }
  50% {
    background-position: 100% 50%;
  }
}

.article-meta {
  display: flex;
  justify-content: center;
  gap: var(--spacing-xl);
  color: var(--text-muted);
  font-size: 0.875rem;
  flex-wrap: wrap;
}

.article-meta-item {
  display: flex;
  align-items: center;
  gap: var(--spacing-sm);
}

.article-meta-item svg {
  width: 16px;
  height: 16px;
  color: var(--accent-primary);
}

/* Article Cover Image */
.article-cover {
  width: 100%;
  max-height: 500px;
  object-fit: cover;
  border-radius: var(--radius-lg);
  margin-bottom: var(--spacing-3xl);
  box-shadow: var(--shadow-soft), var(--shadow-glow);
}

/* Article Content */
.article-content {
  font-size: 1.0625rem;
  line-height: 1.9;
}

.article-content h2 {
  margin-top: var(--spacing-3xl);
  padding-top: var(--spacing-xl);
  border-top: 1px solid var(--border-color);
  position: relative;
}

.article-content h2::before {
  content: "";
  position: absolute;
  top: -1px;
  left: 0;
  width: 60px;
  height: 2px;
  background: var(--accent-gradient);
}

.article-content h3 {
  margin-top: var(--spacing-2xl);
}

.article-content p {
  margin-bottom: var(--spacing-lg);
}

/* Article Footer */
.article-footer {
  margin-top: var(--spacing-3xl);
  padding-top: var(--spacing-xl);
  border-top: 1px solid var(--border-color);
}

/* Tags */
.tags {
  display: flex;
  flex-wrap: wrap;
  gap: var(--spacing-sm);
  margin-bottom: var(--spacing-xl);
}

.tag {
  display: inline-flex;
  align-items: center;
  padding: var(--spacing-xs) var(--spacing-md);
  background: var(--bg-tertiary);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-full);
  font-size: 0.8125rem;
  color: var(--text-secondary);
  transition: all var(--transition-fast);
  cursor: pointer;
}

.tag:hover {
  background: var(--accent-primary);
  border-color: var(--accent-primary);
  color: var(--text-primary);
  transform: translateY(-1px);
}

/* Author Info */
.author-info {
  display: flex;
  align-items: center;
  gap: var(--spacing-md);
  padding: var(--spacing-lg);
  background: var(--bg-card);
  border-radius: var(--radius-md);
  border: 1px solid var(--border-color);
}

.author-avatar {
  width: 48px;
  height: 48px;
  border-radius: 50%;
  object-fit: cover;
  border: 2px solid var(--accent-primary);
}

.author-details {
  flex: 1;
}

.author-name {
  font-weight: 600;
  color: var(--text-primary);
  margin-bottom: 2px;
}

.author-bio {
  font-size: 0.875rem;
  color: var(--text-muted);
}

/* Table of Contents */
.toc {
  position: sticky;
  top: var(--spacing-xl);
  padding: var(--spacing-lg);
  background: var(--bg-card);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-md);
  max-height: calc(100vh - 100px);
  overflow-y: auto;
}

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

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

.toc-item {
  margin-bottom: var(--spacing-sm);
}

.toc-link {
  display: block;
  padding: var(--spacing-xs) var(--spacing-sm);
  color: var(--text-muted);
  font-size: 0.875rem;
  border-left: 2px solid transparent;
  transition: all var(--transition-fast);
}

.toc-link:hover,
.toc-link.active {
  color: var(--accent-primary);
  border-left-color: var(--accent-primary);
  background: var(--bg-card-hover);
}

/* Navigation */
.nav-container {
  display: flex;
  justify-content: space-between;
  margin-top: var(--spacing-2xl);
  padding-top: var(--spacing-xl);
  border-top: 1px solid var(--border-color);
}

.nav-link {
  display: flex;
  align-items: center;
  gap: var(--spacing-sm);
  padding: var(--spacing-md) var(--spacing-lg);
  background: var(--bg-card);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-md);
  color: var(--text-secondary);
  transition: all var(--transition-fast);
  max-width: 45%;
}

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

.nav-link.prev {
  flex-direction: row-reverse;
  text-align: right;
}

.nav-label {
  font-size: 0.75rem;
  color: var(--text-muted);
  margin-bottom: 2px;
}

.nav-title {
  font-weight: 500;
  color: var(--text-primary);
  white-space: nowrap;
  overflow: hidden;
  text-overflow: ellipsis;
}

/* Back to Top Button */
.back-to-top {
  position: fixed;
  bottom: var(--spacing-xl);
  right: var(--spacing-xl);
  width: 48px;
  height: 48px;
  background: var(--accent-gradient);
  border: none;
  border-radius: var(--radius-full);
  color: white;
  cursor: pointer;
  opacity: 0;
  visibility: hidden;
  transform: translateY(20px);
  transition: all var(--transition-normal);
  display: flex;
  align-items: center;
  justify-content: center;
  box-shadow: var(--shadow-glow);
  z-index: 1000;
}

.back-to-top.visible {
  opacity: 1;
  visibility: visible;
  transform: translateY(0);
}

.back-to-top:hover {
  transform: translateY(-4px);
  box-shadow: 0 0 60px rgba(99, 102, 241, 0.3);
}

/* Scrollbar Styling */
::-webkit-scrollbar {
  width: 8px;
  height: 8px;
}

::-webkit-scrollbar-track {
  background: var(--bg-secondary);
}

::-webkit-scrollbar-thumb {
  background: var(--bg-tertiary);
  border-radius: var(--radius-full);
}

::-webkit-scrollbar-thumb:hover {
  background: var(--accent-primary);
}

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

/* Focus States */
:focus-visible {
  outline: 2px solid var(--accent-primary);
  outline-offset: 2px;
}

/* Responsive Design */
@media (max-width: 768px) {
  :root {
    --spacing-3xl: 2rem;
    --spacing-2xl: 1.5rem;
  }

  html {
    font-size: 15px;
  }

  .article-container {
    padding: var(--spacing-2xl) var(--spacing-md);
  }

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

  .article-meta {
    gap: var(--spacing-md);
  }

  .nav-container {
    flex-direction: column;
    gap: var(--spacing-md);
  }

  .nav-link {
    max-width: 100%;
  }

  .toc {
    display: none;
  }
}

/* Print Styles */
@media print {
  body {
    background: white;
    color: #1a1a1a;
  }

  .back-to-top,
  .toc {
    display: none;
  }

  img {
    box-shadow: none;
  }

  a {
    color: inherit;
    text-decoration: underline;
  }

  a::after {
    display: none;
  }
}

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

@keyframes fadeIn {
  from {
    opacity: 0;
  }
  to {
    opacity: 1;
  }
}

@keyframes slideInLeft {
  from {
    opacity: 0;
    transform: translateX(-20px);
  }
  to {
    opacity: 1;
    transform: translateX(0);
  }
}

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

/* Utility Classes */
.fade-in {
  animation: fadeInUp 0.6s ease forwards;
}

.text-gradient {
  background: var(--accent-gradient);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
}

.glass {
  background: rgba(255, 255, 255, 0.05);
  backdrop-filter: blur(10px);
  -webkit-backdrop-filter: blur(10px);
  border: 1px solid rgba(255, 255, 255, 0.1);
}

.hover-lift {
  transition:
    transform var(--transition-normal),
    box-shadow var(--transition-normal);
}

.hover-lift:hover {
  transform: translateY(-4px);
  box-shadow: var(--shadow-glow);
}