/* ============================================
   Xelon HQ Documentation — Main Stylesheet
   ============================================ */

/* --- CSS Custom Properties (Light Theme) --- */
:root {
  --color-primary: #0069FF;
  --color-primary-hover: #0055CC;
  --color-primary-light: #E8F1FF;
  --color-bg: #FFFFFF;
  --color-bg-secondary: #F8FAFC;
  --color-bg-tertiary: #F1F5F9;
  --color-text: #1E293B;
  --color-text-secondary: #64748B;
  --color-text-tertiary: #94A3B8;
  --color-border: #E2E8F0;
  --color-border-hover: #CBD5E1;
  --color-card-bg: #FFFFFF;
  --color-card-shadow: rgba(0, 0, 0, 0.04);
  --color-card-shadow-hover: rgba(0, 0, 0, 0.08);
  --color-sidebar-bg: #F8FAFC;
  --color-sidebar-active: #EFF6FF;
  --color-code-bg: #F1F5F9;
  --color-code-text: #0F172A;
  --color-hero-bg: linear-gradient(135deg, #0069FF 0%, #0047B3 100%);
  --color-success: #10B981;
  --color-warning: #F59E0B;
  --color-danger: #EF4444;
  --color-info: #3B82F6;
  --sidebar-width: 280px;
  --header-height: 64px;
  --content-max-width: 960px;
  --radius-sm: 6px;
  --radius-md: 8px;
  --radius-lg: 12px;
  --shadow-sm: 0 1px 2px var(--color-card-shadow);
  --shadow-md: 0 4px 12px var(--color-card-shadow);
  --shadow-lg: 0 8px 24px var(--color-card-shadow-hover);
  --transition: 0.2s ease;
}

/* --- Dark Theme --- */
[data-theme="dark"] {
  --color-primary: #3B8BFF;
  --color-primary-hover: #5CA0FF;
  --color-primary-light: #1E3A5F;
  --color-bg: #0F172A;
  --color-bg-secondary: #1E293B;
  --color-bg-tertiary: #334155;
  --color-text: #E2E8F0;
  --color-text-secondary: #94A3B8;
  --color-text-tertiary: #64748B;
  --color-border: #334155;
  --color-border-hover: #475569;
  --color-card-bg: #1E293B;
  --color-card-shadow: rgba(0, 0, 0, 0.2);
  --color-card-shadow-hover: rgba(0, 0, 0, 0.3);
  --color-sidebar-bg: #1E293B;
  --color-sidebar-active: #1E3A5F;
  --color-code-bg: #1E293B;
  --color-code-text: #E2E8F0;
  --color-hero-bg: linear-gradient(135deg, #1E3A5F 0%, #0F172A 100%);
}

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

html {
  scroll-behavior: smooth;
  -webkit-text-size-adjust: 100%;
}

body {
  font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, 'Helvetica Neue', Arial, sans-serif;
  font-size: 16px;
  line-height: 1.7;
  color: var(--color-text);
  background: var(--color-bg);
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
}

a {
  color: var(--color-primary);
  text-decoration: none;
  transition: color var(--transition);
}

a:hover {
  color: var(--color-primary-hover);
  text-decoration: underline;
}

img {
  max-width: 100%;
  height: auto;
}

/* --- Typography --- */
h1, h2, h3, h4 {
  color: var(--color-text);
  font-weight: 600;
  line-height: 1.3;
  margin-top: 2rem;
  margin-bottom: 0.75rem;
}

h1 { font-size: 2rem; margin-top: 0; }
h2 { font-size: 1.5rem; padding-bottom: 0.5rem; border-bottom: 1px solid var(--color-border); }
h3 { font-size: 1.25rem; }
h4 { font-size: 1.1rem; }

p {
  margin-bottom: 1rem;
  color: var(--color-text);
}

ul, ol {
  margin-bottom: 1rem;
  padding-left: 1.5rem;
}

li {
  margin-bottom: 0.35rem;
}

/* --- Header --- */
.site-header {
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  height: var(--header-height);
  background: var(--color-bg);
  border-bottom: 1px solid var(--color-border);
  display: flex;
  align-items: center;
  padding: 0 1.5rem;
  z-index: 100;
  backdrop-filter: blur(8px);
}

.header-logo {
  display: flex;
  align-items: center;
  gap: 0.75rem;
  font-size: 1.1rem;
  font-weight: 600;
  color: var(--color-text);
  text-decoration: none;
  white-space: nowrap;
}

.header-logo:hover {
  color: var(--color-text);
  text-decoration: none;
}

.header-logo svg {
  width: 28px;
  height: 28px;
}

.header-center {
  flex: 1;
  display: flex;
  justify-content: center;
  padding: 0 2rem;
}

.header-search {
  position: relative;
  width: 100%;
  max-width: 480px;
}

.header-search input {
  width: 100%;
  height: 40px;
  padding: 0 1rem 0 2.5rem;
  border: 1px solid var(--color-border);
  border-radius: var(--radius-md);
  background: var(--color-bg-secondary);
  color: var(--color-text);
  font-size: 0.875rem;
  outline: none;
  transition: border-color var(--transition), box-shadow var(--transition);
}

.header-search input:focus {
  border-color: var(--color-primary);
  box-shadow: 0 0 0 3px var(--color-primary-light);
}

.header-search input::placeholder {
  color: var(--color-text-tertiary);
}

.header-search .search-icon {
  position: absolute;
  left: 0.75rem;
  top: 50%;
  transform: translateY(-50%);
  color: var(--color-text-tertiary);
  pointer-events: none;
}

.header-search .search-shortcut {
  position: absolute;
  right: 0.75rem;
  top: 50%;
  transform: translateY(-50%);
  font-size: 0.7rem;
  color: var(--color-text-tertiary);
  background: var(--color-bg);
  border: 1px solid var(--color-border);
  border-radius: 4px;
  padding: 2px 6px;
  pointer-events: none;
}

.header-actions {
  display: flex;
  align-items: center;
  gap: 0.5rem;
}

.theme-toggle {
  width: 40px;
  height: 40px;
  border: 1px solid var(--color-border);
  border-radius: var(--radius-md);
  background: var(--color-bg-secondary);
  color: var(--color-text-secondary);
  cursor: pointer;
  display: flex;
  align-items: center;
  justify-content: center;
  transition: all var(--transition);
}

.theme-toggle:hover {
  border-color: var(--color-border-hover);
  color: var(--color-text);
}

.hamburger {
  display: none;
  width: 40px;
  height: 40px;
  border: 1px solid var(--color-border);
  border-radius: var(--radius-md);
  background: var(--color-bg-secondary);
  color: var(--color-text-secondary);
  cursor: pointer;
  align-items: center;
  justify-content: center;
  font-size: 1.25rem;
}

/* --- Layout --- */
.docs-layout {
  display: grid;
  grid-template-columns: var(--sidebar-width) 1fr;
  min-height: calc(100vh - var(--header-height));
  margin-top: var(--header-height);
}

/* --- Sidebar --- */
.sidebar {
  position: fixed;
  top: var(--header-height);
  left: 0;
  bottom: 0;
  width: var(--sidebar-width);
  background: var(--color-sidebar-bg);
  border-right: 1px solid var(--color-border);
  overflow-y: auto;
  padding: 1.5rem 0;
  z-index: 50;
  transition: transform 0.3s ease;
}

.sidebar-section {
  margin-bottom: 0.25rem;
}

.sidebar-heading {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 0.5rem 1.25rem;
  font-size: 0.8rem;
  font-weight: 700;
  color: var(--color-text-secondary);
  text-transform: uppercase;
  letter-spacing: 0.05em;
  cursor: pointer;
  user-select: none;
  transition: color var(--transition);
}

.sidebar-heading:hover {
  color: var(--color-text);
}

.sidebar-heading .chevron {
  font-size: 0.65rem;
  transition: transform var(--transition);
}

.sidebar-heading.collapsed .chevron {
  transform: rotate(-90deg);
}

.sidebar-links {
  list-style: none;
  padding: 0;
  margin: 0;
  overflow: hidden;
  transition: max-height 0.3s ease;
}

.sidebar-links.collapsed {
  max-height: 0 !important;
}

.sidebar-links li a {
  display: block;
  padding: 0.4rem 1.25rem 0.4rem 2rem;
  font-size: 0.875rem;
  color: var(--color-text-secondary);
  border-left: 3px solid transparent;
  transition: all var(--transition);
  text-decoration: none;
}

.sidebar-links li a:hover {
  color: var(--color-text);
  background: var(--color-sidebar-active);
  text-decoration: none;
}

.sidebar-links li a.active {
  color: var(--color-primary);
  border-left-color: var(--color-primary);
  background: var(--color-sidebar-active);
  font-weight: 500;
}

/* --- Main Content --- */
.content {
  padding: 2.5rem 3rem;
  max-width: calc(var(--content-max-width) + 6rem);
}

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

/* --- Breadcrumbs --- */
.breadcrumbs {
  display: flex;
  align-items: center;
  gap: 0.5rem;
  margin-bottom: 1.5rem;
  font-size: 0.85rem;
  color: var(--color-text-tertiary);
}

.breadcrumbs a {
  color: var(--color-text-secondary);
  text-decoration: none;
}

.breadcrumbs a:hover {
  color: var(--color-primary);
  text-decoration: underline;
}

.breadcrumbs .separator {
  color: var(--color-text-tertiary);
  font-size: 0.7rem;
}

.breadcrumbs .current {
  color: var(--color-text);
  font-weight: 500;
}

/* --- Hero Section (Hub pages) --- */
.hero {
  background: var(--color-hero-bg);
  color: #FFFFFF;
  padding: 3.5rem 2rem;
  text-align: center;
  border-radius: var(--radius-lg);
  margin-bottom: 2.5rem;
}

.hero h1 {
  color: #FFFFFF;
  font-size: 2.25rem;
  margin-bottom: 0.75rem;
}

.hero p {
  color: rgba(255, 255, 255, 0.85);
  font-size: 1.1rem;
  max-width: 600px;
  margin: 0 auto 1.5rem;
}

.hero-search {
  position: relative;
  max-width: 520px;
  margin: 0 auto;
}

.hero-search input {
  width: 100%;
  height: 48px;
  padding: 0 1.25rem 0 3rem;
  border: none;
  border-radius: var(--radius-md);
  font-size: 1rem;
  background: rgba(255, 255, 255, 0.15);
  color: #FFFFFF;
  backdrop-filter: blur(4px);
  outline: none;
  transition: background var(--transition);
}

.hero-search input::placeholder {
  color: rgba(255, 255, 255, 0.6);
}

.hero-search input:focus {
  background: rgba(255, 255, 255, 0.25);
}

.hero-search .search-icon {
  position: absolute;
  left: 1rem;
  top: 50%;
  transform: translateY(-50%);
  color: rgba(255, 255, 255, 0.6);
}

/* --- Footer --- */
.site-footer {
  border-top: 1px solid var(--color-border);
  padding: 2rem 0;
  margin-top: 3rem;
  text-align: center;
  font-size: 0.85rem;
  color: var(--color-text-tertiary);
}

.site-footer a {
  color: var(--color-text-secondary);
}

/* --- Search Results Dropdown --- */
.search-results {
  position: absolute;
  top: 100%;
  left: 0;
  right: 0;
  margin-top: 0.5rem;
  background: var(--color-card-bg);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-md);
  box-shadow: var(--shadow-lg);
  max-height: 400px;
  overflow-y: auto;
  z-index: 200;
  display: none;
}

.search-results.visible {
  display: block;
}

.search-results-group {
  padding: 0.5rem 0;
  border-bottom: 1px solid var(--color-border);
}

.search-results-group:last-child {
  border-bottom: none;
}

.search-results-group-title {
  padding: 0.25rem 1rem;
  font-size: 0.7rem;
  font-weight: 700;
  color: var(--color-text-tertiary);
  text-transform: uppercase;
  letter-spacing: 0.05em;
}

.search-result-item {
  display: block;
  padding: 0.5rem 1rem;
  color: var(--color-text);
  text-decoration: none;
  transition: background var(--transition);
}

.search-result-item:hover {
  background: var(--color-bg-secondary);
  text-decoration: none;
}

.search-result-item .title {
  font-weight: 500;
  font-size: 0.9rem;
}

.search-result-item .description {
  font-size: 0.8rem;
  color: var(--color-text-secondary);
  margin-top: 0.15rem;
}

.search-no-results {
  padding: 1.5rem;
  text-align: center;
  color: var(--color-text-tertiary);
  font-size: 0.9rem;
}

/* --- Responsive --- */
@media (max-width: 1024px) {
  .hamburger {
    display: flex;
  }

  .docs-layout {
    grid-template-columns: 1fr;
  }

  .sidebar {
    transform: translateX(-100%);
  }

  .sidebar.open {
    transform: translateX(0);
    box-shadow: var(--shadow-lg);
  }

  .content {
    padding: 2rem 1.5rem;
  }

  .header-center {
    padding: 0 1rem;
  }
}

@media (max-width: 768px) {
  .hero {
    padding: 2.5rem 1.5rem;
  }

  .hero h1 {
    font-size: 1.75rem;
  }

  h1 { font-size: 1.75rem; }
  h2 { font-size: 1.3rem; }

  .content {
    padding: 1.5rem 1rem;
  }

  .header-search {
    display: none;
  }
}