/* Custom Reset and Variables */
:root {
  --bg-color: #090a0f;
  --navbar-bg: rgba(9, 10, 15, 0.9);
  --surface-color: #11131e;
  --surface-border: #23263a;
  --primary-color: #a855f7;
  --primary-hover: #c084fc;
  --text-main: #f3f4f6;
  --text-muted: #9ca3af;
  --text-inverse: #090a0f;
  --accent-color: #6366f1;
  --highlight-bg: rgba(168, 85, 247, 0.1);
  --table-header-bg: #1a1c2c;
  --table-border: #1e2135;
  --font-stack: system-ui, -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "Helvetica Neue", Arial, sans-serif;
  --max-width: 1200px;
}

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

body {
  font-family: var(--font-stack);
  background-color: var(--bg-color);
  color: var(--text-main);
  line-height: 1.6;
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
}

/* Scrollbar styling */
::-webkit-scrollbar {
  width: 10px;
}
::-webkit-scrollbar-track {
  background: var(--bg-color);
}
::-webkit-scrollbar-thumb {
  background: var(--surface-border);
  border-radius: 5px;
}
::-webkit-scrollbar-thumb:hover {
  background: var(--primary-color);
}

/* Accessibility: focus ring */
*:focus-visible {
  outline: 3px solid var(--primary-color);
  outline-offset: 2px;
}

/* Shared Containers */
.container {
  width: 100%;
  max-width: var(--max-width);
  margin-left: auto;
  margin-right: auto;
  padding-left: 20px;
  padding-right: 20px;
}

/* Navbar */
.navbar {
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  height: 70px;
  background-color: var(--navbar-bg);
  backdrop-filter: blur(12px);
  border-bottom: 1px solid var(--surface-border);
  z-index: 1000;
  display: flex;
  align-items: center;
}

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

.brand {
  display: flex;
  align-items: center;
  gap: 10px;
}

.brand-logo {
  color: var(--primary-color);
}

.brand-title {
  font-size: 1.25rem;
  font-weight: 800;
  letter-spacing: -0.025em;
  background: linear-gradient(to right, #c084fc, #6366f1);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
}

.nav-links .nav-btn {
  text-decoration: none;
  background-color: var(--surface-color);
  color: var(--text-main);
  border: 1px solid var(--surface-border);
  padding: 8px 16px;
  border-radius: 8px;
  font-size: 0.875rem;
  font-weight: 600;
  transition: all 0.2s ease;
}

.nav-links .nav-btn:hover {
  border-color: var(--primary-color);
  color: var(--primary-hover);
}

/* Hero Section */
.hero {
  padding-top: 130px;
  padding-bottom: 40px;
  border-bottom: 1px solid var(--surface-border);
  background: radial-gradient(circle at top right, rgba(168, 85, 247, 0.08), transparent 45%);
}

.hero-tag {
  color: var(--primary-color);
  font-size: 0.875rem;
  font-weight: 700;
  text-transform: uppercase;
  letter-spacing: 0.1em;
  margin-bottom: 8px;
}

.hero-title {
  font-size: 3rem;
  font-weight: 850;
  letter-spacing: -0.04em;
  line-height: 1.1;
  margin-bottom: 16px;
}

.hero-subtitle {
  font-size: 1.15rem;
  color: var(--text-muted);
  max-width: 750px;
  margin-bottom: 24px;
}

.meta-info {
  display: flex;
  flex-wrap: wrap;
  gap: 20px;
  font-size: 0.875rem;
}

.meta-item {
  color: var(--text-muted);
  border: 1px solid var(--surface-border);
  padding: 4px 12px;
  border-radius: 6px;
  background-color: rgba(255, 255, 255, 0.02);
}

/* Layout and Grid */
.main-layout {
  display: grid;
  grid-template-columns: 280px 1fr;
  gap: 40px;
  padding-top: 50px;
  padding-bottom: 100px;
}

/* Sidebar / Table of Contents */
.toc-sidebar {
  position: relative;
}

.toc-sticky {
  position: sticky;
  top: 95px;
  max-height: calc(100vh - 120px);
  overflow-y: auto;
  padding-right: 10px;
}

.toc-header {
  font-size: 0.9rem;
  text-transform: uppercase;
  letter-spacing: 0.05em;
  color: var(--primary-color);
  margin-bottom: 15px;
  font-weight: 700;
}

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

.toc-list li {
  margin-bottom: 10px;
}

.toc-list a {
  text-decoration: none;
  color: var(--text-muted);
  font-size: 0.925rem;
  transition: color 0.15s ease;
  display: block;
  line-height: 1.4;
}

.toc-list a:hover {
  color: var(--text-main);
  border-left: 2px solid var(--primary-color);
  padding-left: 8px;
}

/* Content Body */
.content-body h2 {
  font-size: 1.75rem;
  font-weight: 750;
  margin-top: 40px;
  margin-bottom: 16px;
  color: #fff;
  letter-spacing: -0.02em;
  scroll-margin-top: 100px; /* offset for nav scrolling */
}

.content-body p {
  color: var(--text-muted);
  margin-bottom: 20px;
  font-size: 1.05rem;
}

.content-body a {
  color: var(--primary-color);
  text-decoration: underline;
  text-decoration-thickness: 1px;
  text-underline-offset: 4px;
}

.content-body a:hover {
  color: var(--primary-hover);
}

.content-body ul, .content-body ol {
  margin-bottom: 24px;
  padding-left: 20px;
  color: var(--text-muted);
}

.content-body li {
  margin-bottom: 10px;
  font-size: 1rem;
}

.content-body strong {
  color: #fff;
}

/* Decorative and Highlight Components */
.highlight-box {
  background-color: var(--highlight-bg);
  border-left: 4px solid var(--primary-color);
  padding: 16px;
  border-radius: 0 8px 8px 0;
  margin: 25px 0;
}

.highlight-box p {
  margin-bottom: 0;
  color: var(--text-main);
  font-weight: 500;
}

/* Tables styling */
table {
  width: 100%;
  border-collapse: collapse;
  margin-top: 30px;
  margin-bottom: 30px;
  font-size: 0.95rem;
  border: 1px solid var(--surface-border);
  border-radius: 8px;
  overflow: hidden;
}

th, td {
  padding: 14px 18px;
  text-align: left;
}

th {
  background-color: var(--table-header-bg);
  color: #fff;
  font-weight: 700;
  border-bottom: 2px solid var(--surface-border);
}

td {
  background-color: var(--surface-color);
  border-bottom: 1px solid var(--table-border);
  color: var(--text-muted);
  vertical-align: top;
}

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

code {
  font-family: SFMono-Regular, Consolas, "Liberation Mono", Menlo, monospace;
  background-color: rgba(255, 255, 255, 0.08);
  padding: 3px 6px;
  border-radius: 4px;
  font-size: 0.9em;
  color: var(--primary-hover);
}

/* Footer styling */
.footer {
  background-color: #05060a;
  border-top: 1px solid var(--surface-border);
  padding: 40px 0;
  font-size: 0.875rem;
  color: var(--text-muted);
}

.footer-container {
  display: flex;
  flex-direction: column;
  gap: 15px;
  align-items: center;
  text-align: center;
}

.footer-disclaimer {
  max-width: 700px;
  font-size: 0.8rem;
  line-height: 1.5;
}

/* Responsive Rules */
@media (max-width: 1024px) {
  .main-layout {
    grid-template-columns: 1fr;
    gap: 0;
  }
  .toc-sidebar {
    display: none; /* Hide sidebar list on mobile/tablet screens for simplicity */
  }
  .hero-title {
    font-size: 2.5rem;
  }
}

@media (max-width: 640px) {
  .hero-title {
    font-size: 2rem;
  }
  .navbar-container {
    flex-direction: column;
    gap: 10px;
  }
  .navbar {
    height: 90px;
  }
  .hero {
    padding-top: 130px;
  }
  th, td {
    padding: 10px 12px;
    font-size: 0.85rem;
  }
}

/* High Contrast & Print accessibility */
@media print {
  body {
    background-color: #fff;
    color: #000;
  }
  .navbar, .toc-sidebar, .footer, .nav-links {
    display: none;
  }
  .hero {
    padding-top: 20px;
    background: none;
  }
  .content-body h2 {
    color: #000;
  }
  .content-body p, .content-body li, td {
    color: #333;
  }
}