@import url('https://fonts.googleapis.com/css2?family=Fira+Code:wght@400;500;600&family=Inter:wght@300;400;500;600;700&family=Plus+Jakarta+Sans:wght@400;500;600;700;800&display=swap');

:root {
  --bg-dark: #05070a;
  --bg-card: rgba(13, 17, 23, 0.7);
  --bg-card-hover: rgba(22, 27, 34, 0.9);
  --border-subtle: rgba(255, 255, 255, 0.08);
  --border-glow: rgba(56, 189, 248, 0.3);
  --accent-cyan: #38bdf8;
  --accent-indigo: #818cf8;
  --accent-purple: #c084fc;
  --text-main: #f8fafc;
  --text-muted: #94a3b8;
  --text-dim: #64748b;
  --font-body: 'Inter', -apple-system, BlinkMacSystemFont, sans-serif;
  --font-title: 'Plus Jakarta Sans', sans-serif;
  --font-code: 'Fira Code', monospace;
}

* { box-sizing: border-box; margin: 0; padding: 0; }
html { scroll-behavior: smooth; }

body {
  background-color: var(--bg-dark);
  color: var(--text-main);
  font-family: var(--font-body);
  line-height: 1.8;
  font-size: 1.1rem;
  overflow-x: hidden;
  background-image: 
    radial-gradient(circle at 10% 10%, rgba(56, 189, 248, 0.08) 0%, transparent 45%),
    radial-gradient(circle at 90% 50%, rgba(129, 140, 248, 0.08) 0%, transparent 45%),
    radial-gradient(circle at 50% 90%, rgba(192, 132, 252, 0.05) 0%, transparent 45%);
  background-attachment: fixed;
}

#reading-progress {
  position: fixed;
  top: 0;
  left: 0;
  height: 3px;
  background: linear-gradient(90deg, #38bdf8, #818cf8, #c084fc);
  width: 0%;
  z-index: 1000;
  transition: width 0.1s ease-out;
  box-shadow: 0 0 10px rgba(56, 189, 248, 0.7);
}

.site-header {
  position: sticky;
  top: 0;
  z-index: 100;
  background: rgba(5, 7, 10, 0.85);
  backdrop-filter: blur(20px);
  -webkit-backdrop-filter: blur(20px);
  border-bottom: 1px solid var(--border-subtle);
  padding: 1rem 2rem;
}
.header-container {
  max-width: 1320px;
  margin: 0 auto;
  display: flex;
  justify-content: space-between;
  align-items: center;
}
.site-logo {
  display: flex;
  align-items: center;
  gap: 12px;
  text-decoration: none;
  font-family: var(--font-title);
  font-weight: 800;
  font-size: 1.3rem;
  color: #fff;
  letter-spacing: -0.02em;
}
.site-logo span.glow {
  background: linear-gradient(135deg, #38bdf8, #818cf8);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
}
.nav-links { display: flex; gap: 1.5rem; list-style: none; align-items: center; }
.nav-links a {
  color: var(--text-muted);
  text-decoration: none;
  font-size: 0.9rem;
  font-weight: 500;
  transition: all 0.2s;
}
.nav-links a:hover { color: #fff; text-shadow: 0 0 8px rgba(255,255,255,0.4); }
.nav-badge {
  background: linear-gradient(135deg, rgba(56, 189, 248, 0.15), rgba(129, 140, 248, 0.15));
  border: 1px solid var(--border-glow);
  color: var(--accent-cyan) !important;
  padding: 6px 16px;
  border-radius: 30px;
  font-weight: 600 !important;
}

.article-layout {
  max-width: 1280px;
  margin: 3.5rem auto;
  padding: 0 1.5rem;
  display: grid;
  grid-template-columns: minmax(0, 800px) 300px;
  gap: 4rem;
  justify-content: center;
}
@media (max-width: 1024px) {
  .article-layout { grid-template-columns: 1fr; }
  .toc-sidebar { display: none; }
}

.article-wrapper {
  background: var(--bg-card);
  border: 1px solid var(--border-subtle);
  border-radius: 24px;
  padding: 4rem 3.5rem;
  box-shadow: 0 25px 50px -12px rgba(0, 0, 0, 0.6);
  backdrop-filter: blur(16px);
}
@media (max-width: 640px) {
  .article-wrapper { padding: 2.25rem 1.5rem; }
}

.article-hero {
  margin-bottom: 3rem;
  border-bottom: 1px solid var(--border-subtle);
  padding-bottom: 2.5rem;
}
.category-badge {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  background: linear-gradient(135deg, rgba(56, 189, 248, 0.12), rgba(192, 132, 252, 0.12));
  border: 1px solid var(--border-glow);
  color: var(--accent-cyan);
  font-family: var(--font-title);
  font-size: 0.82rem;
  font-weight: 700;
  text-transform: uppercase;
  letter-spacing: 0.12em;
  padding: 6px 16px;
  border-radius: 30px;
  margin-bottom: 1.5rem;
}
.article-title {
  font-family: var(--font-title);
  font-size: 3rem;
  font-weight: 800;
  line-height: 1.18;
  color: #ffffff;
  margin-bottom: 1.5rem;
  letter-spacing: -0.03em;
  background: linear-gradient(180deg, #ffffff 0%, #cbd5e1 100%);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
}
@media (max-width: 640px) {
  .article-title { font-size: 2.2rem; }
}

.article-author-card {
  display: flex;
  align-items: center;
  gap: 1rem;
  margin-top: 1.75rem;
}
.author-avatar {
  width: 44px;
  height: 44px;
  border-radius: 50%;
  background: linear-gradient(135deg, #38bdf8, #818cf8);
  display: flex;
  align-items: center;
  justify-content: center;
  font-weight: 800;
  color: #000;
  font-family: var(--font-title);
  box-shadow: 0 0 15px rgba(56, 189, 248, 0.4);
}
.author-info { font-size: 0.9rem; }
.author-name { font-weight: 700; color: #fff; font-family: var(--font-title); }
.article-submeta { color: var(--text-dim); font-size: 0.82rem; }

.article-content { font-size: 1.125rem; color: #e2e8f0; line-height: 1.85; }
.article-content > p:first-of-type::first-letter {
  font-family: var(--font-title);
  font-size: 3.5rem;
  float: left;
  line-height: 1;
  margin-right: 0.75rem;
  margin-top: 0.1rem;
  color: var(--accent-cyan);
  font-weight: 800;
}
.article-content h2 {
  font-family: var(--font-title);
  font-size: 2rem;
  font-weight: 800;
  color: #fff;
  margin: 3.25rem 0 1.25rem;
  padding-bottom: 0.6rem;
  border-bottom: 1px solid var(--border-subtle);
  letter-spacing: -0.02em;
}
.article-content h3 {
  font-family: var(--font-title);
  font-size: 1.45rem;
  font-weight: 700;
  color: var(--accent-cyan);
  margin: 2.5rem 0 1rem;
  letter-spacing: -0.01em;
}
.article-content h4 {
  font-family: var(--font-title);
  font-size: 1.2rem;
  font-weight: 600;
  color: var(--accent-indigo);
  margin: 1.75rem 0 0.75rem;
}
.article-content p { margin-bottom: 1.75rem; color: #cbd5e1; }
.article-content ul, .article-content ol { margin: 1.25rem 0 1.75rem 1.75rem; }
.article-content li { margin-bottom: 0.6rem; color: #cbd5e1; }
.article-content strong { color: #ffffff; font-weight: 700; }
.article-content blockquote {
  border-left: 4px solid var(--accent-cyan);
  background: linear-gradient(90deg, rgba(56, 189, 248, 0.08), transparent);
  padding: 1.5rem 2rem;
  border-radius: 0 16px 16px 0;
  margin: 2.25rem 0;
  font-style: italic;
  color: #f1f5f9;
  font-size: 1.15rem;
}

.math-block {
  background: rgba(10, 14, 23, 0.95);
  border: 1px solid var(--border-glow);
  border-radius: 16px;
  padding: 1.75rem 2rem;
  margin: 2.25rem 0;
  overflow-x: auto;
  text-align: center;
  font-size: 1.15rem;
  box-shadow: 0 10px 30px rgba(0, 0, 0, 0.4);
}

/* CODE BLOCKS & ASCII ART DIAGRAMS — STRICT PRESERVED ALIGNMENT */
pre, .code-block {
  font-family: var(--font-code) !important;
  background: #090d14 !important;
  border: 1px solid var(--border-glow) !important;
  border-radius: 16px !important;
  padding: 1.5rem 1.75rem !important;
  overflow-x: auto !important;
  white-space: pre !important;
  word-break: normal !important;
  word-wrap: normal !important;
  font-size: 0.85rem !important;
  line-height: 1.45 !important;
  color: #38bdf8 !important;
  margin: 2.25rem 0 !important;
  box-shadow: 0 15px 35px rgba(0, 0, 0, 0.5);
}
pre code, .code-block code {
  background: none !important;
  border: none !important;
  padding: 0 !important;
  color: #38bdf8 !important;
  white-space: pre !important;
  word-break: normal !important;
  word-wrap: normal !important;
  font-family: var(--font-code) !important;
}

figure.article-img-container {
  margin: 3rem 0;
  text-align: center;
  background: rgba(13, 17, 23, 0.8);
  border: 1px solid var(--border-glow);
  border-radius: 20px;
  padding: 2rem;
  box-shadow: 0 20px 40px rgba(0,0,0,0.5);
}
figure.article-img-container img {
  max-width: 100%;
  height: auto;
  border-radius: 12px;
  box-shadow: 0 12px 35px rgba(0,0,0,0.6);
  transition: transform 0.3s ease;
}
figcaption {
  font-size: 0.9rem;
  color: var(--text-muted);
  margin-top: 1.25rem;
  font-style: italic;
}

.toc-sidebar {
  position: sticky;
  top: 6rem;
  align-self: start;
  background: var(--bg-card);
  border: 1px solid var(--border-subtle);
  border-radius: 20px;
  padding: 1.75rem;
  backdrop-filter: blur(16px);
  box-shadow: 0 15px 35px rgba(0,0,0,0.4);
}
.toc-title {
  font-family: var(--font-title);
  font-size: 0.85rem;
  font-weight: 800;
  text-transform: uppercase;
  letter-spacing: 0.12em;
  color: var(--accent-cyan);
  margin-bottom: 1.25rem;
  display: flex;
  align-items: center;
  gap: 8px;
}
.toc-list { list-style: none; }
.toc-list li { margin-bottom: 0.75rem; }
.toc-list a {
  color: var(--text-muted);
  text-decoration: none;
  font-size: 0.88rem;
  transition: all 0.2s;
  display: block;
  line-height: 1.4;
  font-weight: 500;
}
.toc-list a:hover {
  color: var(--accent-cyan);
  transform: translateX(4px);
}

.hub-hero {
  text-align: center;
  max-width: 850px;
  margin: 4rem auto 4.5rem;
  padding: 0 1.5rem;
}
.hub-hero h1 {
  font-family: var(--font-title);
  font-size: 3.5rem;
  font-weight: 800;
  color: #fff;
  margin-bottom: 1.25rem;
  letter-spacing: -0.03em;
  background: linear-gradient(180deg, #ffffff 0%, #cbd5e1 100%);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
}
.hub-hero p { font-size: 1.25rem; color: var(--text-muted); line-height: 1.6; }

.card-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(370px, 1fr));
  gap: 2.25rem;
  max-width: 1320px;
  margin: 0 auto 6rem;
  padding: 0 1.5rem;
}
.article-card {
  background: var(--bg-card);
  border: 1px solid var(--border-subtle);
  border-radius: 20px;
  padding: 2.25rem;
  display: flex;
  flex-direction: column;
  justify-content: space-between;
  text-decoration: none;
  color: inherit;
  transition: all 0.35s cubic-bezier(0.4, 0, 0.2, 1);
  position: relative;
  overflow: hidden;
}
.article-card::before {
  content: '';
  position: absolute;
  top: 0; left: 0; right: 0; height: 3px;
  background: linear-gradient(90deg, #38bdf8, #818cf8);
  opacity: 0;
  transition: opacity 0.3s ease;
}
.article-card:hover {
  transform: translateY(-8px);
  background: var(--bg-card-hover);
  border-color: var(--border-glow);
  box-shadow: 0 20px 45px rgba(56, 189, 248, 0.15);
}
.article-card:hover::before { opacity: 1; }

.card-meta {
  display: flex;
  justify-content: space-between;
  align-items: center;
  margin-bottom: 1.25rem;
  font-size: 0.82rem;
}
.card-title {
  font-family: var(--font-title);
  font-size: 1.45rem;
  font-weight: 700;
  color: #fff;
  margin-bottom: 1rem;
  line-height: 1.35;
  letter-spacing: -0.01em;
}
.card-excerpt {
  font-size: 0.98rem;
  color: var(--text-muted);
  line-height: 1.65;
  margin-bottom: 1.75rem;
  flex-grow: 1;
}
.card-footer {
  display: flex;
  align-items: center;
  justify-content: space-between;
  font-size: 0.88rem;
  color: var(--accent-cyan);
  font-weight: 600;
  font-family: var(--font-title);
}

.site-footer {
  border-top: 1px solid var(--border-subtle);
  background: rgba(5, 7, 10, 0.95);
  padding: 4rem 1.5rem;
  margin-top: 6rem;
  text-align: center;
  font-size: 0.9rem;
  color: var(--text-dim);
}