/* ================================================================
   HCDF Website — style.css
   Dark theme. GitHub-dark inspired color palette.
   ================================================================ */

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

:root {
  --color-bg: #0d1117;
  --color-surface: #161b22;
  --color-surface-elevated: #1c2128;
  --color-text: #e6edf3;
  --color-text-muted: #8b949e;
  --color-primary: #58a6ff;
  --color-primary-light: #79c0ff;
  --color-primary-dark: #388bfd;
  --color-accent: #58a6ff;
  --color-accent-green: #3fb950;
  --color-accent-orange: #d29922;
  --color-border: #30363d;
  --color-nav-bg: #010409;
  --color-nav-text: #e6edf3;
  --color-nav-hover: #58a6ff;
  --color-card-bg: #161b22;
  --color-card-border: #30363d;
  --color-code-bg: #0d1117;
  --color-code-border: #30363d;
  --color-footer-bg: #010409;
  --color-footer-text: #8b949e;
  --font-sans: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "Helvetica Neue", Arial, sans-serif;
  --font-mono: "SFMono-Regular", Consolas, "Liberation Mono", Menlo, monospace;
  --max-width: 1100px;
  --nav-height: 56px;
}

html {
  font-size: 16px;
  scroll-behavior: smooth;
}

body {
  font-family: var(--font-sans);
  color: var(--color-text);
  background: var(--color-bg);
  line-height: 1.65;
  padding-top: var(--nav-height);
}

a {
  color: var(--color-accent);
  text-decoration: none;
}
a:hover {
  color: var(--color-primary-light);
  text-decoration: underline;
}

img {
  max-width: 100%;
}

/* --- Nav Bar --- */
nav {
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  z-index: 1000;
  background: var(--color-nav-bg);
  height: var(--nav-height);
  display: flex;
  align-items: center;
  padding: 0 1.5rem;
  box-shadow: 0 1px 3px rgba(0, 0, 0, 0.5);
  border-bottom: 1px solid var(--color-border);
}

nav .brand {
  font-weight: 700;
  font-size: 1.25rem;
  color: var(--color-nav-text);
  text-decoration: none;
  letter-spacing: 0.04em;
  margin-right: 2rem;
  white-space: nowrap;
}
nav .brand:hover {
  color: var(--color-nav-hover);
  text-decoration: none;
}

nav .nav-links {
  display: flex;
  align-items: center;
  gap: 0;
  flex: 1;
}

nav .nav-links > a,
nav .nav-links > .dropdown > a {
  color: var(--color-nav-text);
  text-decoration: none;
  padding: 0 1rem;
  line-height: var(--nav-height);
  display: block;
  font-size: 0.9rem;
  white-space: nowrap;
  cursor: pointer;
  transition: color 0.15s;
}
nav .nav-links > a:hover,
nav .nav-links > .dropdown > a:hover,
nav .nav-links > a.active,
nav .nav-links > .dropdown.active > a {
  color: var(--color-nav-hover);
  text-decoration: none;
}

/* Dropdown */
.dropdown {
  position: relative;
}

.dropdown-content {
  display: none;
  position: absolute;
  top: var(--nav-height);
  left: 0;
  min-width: 220px;
  background: var(--color-nav-bg);
  border: 1px solid var(--color-border);
  border-top: none;
  box-shadow: 0 4px 12px rgba(0, 0, 0, 0.5);
  z-index: 1001;
}

.dropdown.open .dropdown-content {
  display: block;
}

.dropdown-content a {
  display: block;
  padding: 0.6rem 1rem;
  color: var(--color-nav-text);
  font-size: 0.85rem;
  text-decoration: none;
  transition: background 0.15s;
}
.dropdown-content a:hover {
  background: var(--color-surface-elevated);
  color: var(--color-nav-hover);
  text-decoration: none;
}

/* Hamburger */
.hamburger {
  display: none;
  background: none;
  border: none;
  cursor: pointer;
  padding: 0.5rem;
  margin-left: auto;
}
.hamburger span {
  display: block;
  width: 22px;
  height: 2px;
  background: var(--color-nav-text);
  margin: 5px 0;
  transition: transform 0.2s, opacity 0.2s;
}
.hamburger.open span:nth-child(1) {
  transform: translateY(7px) rotate(45deg);
}
.hamburger.open span:nth-child(2) {
  opacity: 0;
}
.hamburger.open span:nth-child(3) {
  transform: translateY(-7px) rotate(-45deg);
}

/* --- Content --- */
.content {
  max-width: var(--max-width);
  margin: 0 auto;
  padding: 2rem 1.5rem;
}

h1 {
  font-size: 2rem;
  font-weight: 700;
  margin-bottom: 1rem;
  color: var(--color-text);
}

h2 {
  font-size: 1.5rem;
  font-weight: 600;
  margin-top: 2.5rem;
  margin-bottom: 0.75rem;
  color: var(--color-text);
}

h3 {
  font-size: 1.2rem;
  font-weight: 600;
  margin-top: 1.5rem;
  margin-bottom: 0.5rem;
  color: var(--color-text);
}

p {
  margin-bottom: 1rem;
}

ul, ol {
  margin-bottom: 1rem;
  padding-left: 1.5rem;
}
li {
  margin-bottom: 0.35rem;
}

/* --- Hero --- */
.hero {
  text-align: center;
  padding: 4rem 1.5rem;
  background: linear-gradient(135deg, #0d1117 0%, #161b22 100%);
  color: var(--color-text);
  margin: -2rem -1.5rem 2rem -1.5rem;
  border-bottom: 1px solid var(--color-border);
}
.hero h1 {
  font-size: 2.5rem;
  color: #fff;
  margin-bottom: 0.5rem;
}
.hero .tagline {
  font-size: 1.15rem;
  color: var(--color-text-muted);
  margin-bottom: 0.25rem;
}
.hero .version {
  font-size: 0.85rem;
  color: var(--color-primary);
  margin-top: 0.75rem;
}

/* --- Feature Cards --- */
.cards {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
  gap: 1.5rem;
  margin: 2rem 0;
}

.card {
  background: var(--color-card-bg);
  border: 1px solid var(--color-card-border);
  border-radius: 8px;
  padding: 1.5rem;
  transition: box-shadow 0.2s, border-color 0.2s;
}
.card:hover {
  box-shadow: 0 4px 16px rgba(56, 139, 253, 0.1);
  border-color: var(--color-primary-dark);
}
.card h3 {
  margin-top: 0;
  color: var(--color-primary);
  font-size: 1.1rem;
}
.card p {
  color: var(--color-text-muted);
  font-size: 0.93rem;
}

.card-link {
  display: block;
  text-decoration: none;
  color: inherit;
}
.card-link:hover {
  text-decoration: none;
}

/* --- Code Blocks --- */
pre[class*="language-"] {
  background: var(--color-code-bg) !important;
  border: 1px solid var(--color-code-border);
  border-radius: 6px;
  padding: 1rem 1.25rem;
  overflow-x: auto;
  font-size: 0.85rem;
  line-height: 1.5;
  margin-bottom: 1.5rem;
}
code {
  font-family: var(--font-mono);
  font-size: 0.88em;
}
:not(pre) > code {
  background: var(--color-surface-elevated);
  border: 1px solid var(--color-border);
  padding: 0.15em 0.4em;
  border-radius: 3px;
  font-size: 0.85em;
  color: var(--color-primary-light);
}

/* --- Collapsible Sections --- */
.collapsible {
  border: 1px solid var(--color-card-border);
  border-radius: 8px;
  margin-bottom: 1rem;
  overflow: hidden;
}

.collapsible-header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 0.8rem 1.25rem;
  background: var(--color-surface-elevated);
  cursor: pointer;
  user-select: none;
  font-weight: 600;
  font-size: 1rem;
  color: var(--color-text);
  transition: background 0.15s;
}
.collapsible-header:hover {
  background: #262c36;
}

.collapsible-header .indicator {
  font-size: 1.2rem;
  font-weight: 400;
  color: var(--color-text-muted);
  width: 1.5rem;
  text-align: center;
  flex-shrink: 0;
}

.collapsible-body {
  display: none;
  padding: 1rem 1.25rem;
  border-top: 1px solid var(--color-card-border);
  background: var(--color-surface);
}

.collapsible.open .collapsible-body {
  display: block;
}

.collapsible-body pre[class*="language-"] {
  margin-bottom: 1rem;
}

/* --- Tree View (for spec browser) --- */
.tree ul {
  list-style: none;
  padding-left: 1.25rem;
}
.tree > ul {
  padding-left: 0;
}
.tree li {
  position: relative;
  padding: 0.15rem 0;
}
.tree li::before {
  content: "";
  position: absolute;
  left: -0.75rem;
  top: 0;
  bottom: 0;
  width: 1px;
  background: var(--color-border);
}
.tree li:last-child::before {
  bottom: 50%;
}
.tree li::after {
  content: "";
  position: absolute;
  left: -0.75rem;
  top: 50%;
  width: 0.75rem;
  height: 1px;
  background: var(--color-border);
}
.tree > ul > li::before,
.tree > ul > li::after {
  display: none;
}

/* Tree element names in blue, attributes in green */
.tree .element,
.tree .tag {
  color: var(--color-primary);
  font-weight: 600;
}
.tree .attr,
.tree .attribute {
  color: var(--color-accent-green);
}

/* --- Stats Grid --- */
.stats {
  display: flex;
  gap: 2rem;
  flex-wrap: wrap;
  margin: 1.5rem 0;
}
.stat {
  text-align: center;
}
.stat .stat-value {
  font-size: 2rem;
  font-weight: 700;
  color: var(--color-primary);
}
.stat .stat-label {
  font-size: 0.85rem;
  color: var(--color-text-muted);
}

/* --- Quick Start --- */
.quickstart {
  background: var(--color-card-bg);
  border: 1px solid var(--color-card-border);
  border-radius: 8px;
  padding: 1.5rem;
  margin: 2rem 0;
}
.quickstart h3 {
  margin-top: 0;
}

/* --- Comparison Table --- */
table {
  width: 100%;
  border-collapse: collapse;
  margin-bottom: 1.5rem;
  font-size: 0.9rem;
}
th, td {
  padding: 0.6rem 0.8rem;
  text-align: left;
  border-bottom: 1px solid var(--color-border);
}
th {
  background: var(--color-surface-elevated);
  font-weight: 600;
  color: var(--color-text);
}
/* Alternating row colors */
tr:nth-child(even) td {
  background: var(--color-surface);
}
tr:nth-child(odd) td {
  background: var(--color-bg);
}
tr:hover td {
  background: var(--color-surface-elevated);
}

/* --- Section Divider --- */
.section-divider {
  border: none;
  border-top: 1px solid var(--color-border);
  margin: 2.5rem 0;
}

/* --- Inline Badge --- */
.badge {
  display: inline-block;
  padding: 0.15em 0.55em;
  font-size: 0.75rem;
  font-weight: 600;
  border-radius: 4px;
  background: var(--color-primary);
  color: #fff;
  vertical-align: middle;
}

/* --- Footer --- */
footer {
  background: var(--color-footer-bg);
  border-top: 1px solid var(--color-border);
  padding: 1.5rem;
  text-align: center;
  color: var(--color-footer-text);
  font-size: 0.85rem;
  margin-top: 3rem;
}
footer a {
  color: var(--color-text-muted);
}
footer a:hover {
  color: var(--color-primary);
}

/* --- Alert / Note --- */
.note {
  background: rgba(56, 139, 253, 0.1);
  border-left: 4px solid var(--color-primary);
  padding: 0.8rem 1rem;
  margin-bottom: 1.5rem;
  border-radius: 0 6px 6px 0;
  font-size: 0.9rem;
  color: var(--color-text);
}

/* --- Responsive --- */
@media (max-width: 768px) {
  .hero h1 {
    font-size: 1.8rem;
  }
  .hero {
    padding: 2.5rem 1rem;
  }

  .hamburger {
    display: block;
  }

  nav .nav-links {
    display: none;
    position: absolute;
    top: var(--nav-height);
    left: 0;
    right: 0;
    background: var(--color-nav-bg);
    flex-direction: column;
    align-items: stretch;
    border-top: 1px solid var(--color-border);
    box-shadow: 0 4px 12px rgba(0, 0, 0, 0.5);
  }
  nav .nav-links.open {
    display: flex;
  }

  nav .nav-links > a,
  nav .nav-links > .dropdown > a {
    padding: 0.75rem 1.5rem;
    line-height: 1.5;
    border-bottom: 1px solid var(--color-border);
  }

  .dropdown-content {
    position: static;
    box-shadow: none;
    border: none;
    background: var(--color-surface-elevated);
  }
  .dropdown-content a {
    padding-left: 2.5rem;
  }

  .cards {
    grid-template-columns: 1fr;
  }

  .stats {
    justify-content: center;
  }

  h1 { font-size: 1.6rem; }
  h2 { font-size: 1.3rem; }

  table {
    display: block;
    overflow-x: auto;
  }
}

/* ================================================================
   Prism.js Dark Override — "Tomorrow Night" style
   Forces dark syntax highlighting regardless of which Prism CSS
   theme is loaded in the HTML files.
   ================================================================ */

code[class*="language-"],
pre[class*="language-"] {
  color: #c9d1d9 !important;
  background: var(--color-code-bg) !important;
  text-shadow: none !important;
  font-family: var(--font-mono) !important;
  direction: ltr !important;
  text-align: left !important;
  white-space: pre !important;
  word-spacing: normal !important;
  word-break: normal !important;
  line-height: 1.5 !important;
  tab-size: 4 !important;
  hyphens: none !important;
}

pre[class*="language-"]::selection,
pre[class*="language-"] ::selection,
code[class*="language-"]::selection,
code[class*="language-"] ::selection {
  background: #3b4252 !important;
}

/* Line numbers */
.line-numbers .line-numbers-rows {
  border-right-color: var(--color-border) !important;
}
.line-numbers-rows > span::before {
  color: #484f58 !important;
}

/* Token colors — Tomorrow Night / GitHub Dark palette */
.token.comment,
.token.prolog,
.token.doctype,
.token.cdata {
  color: #8b949e !important;
}

.token.punctuation {
  color: #c9d1d9 !important;
}

.token.namespace {
  opacity: 0.7 !important;
}

.token.property,
.token.tag,
.token.boolean,
.token.number,
.token.constant,
.token.symbol,
.token.deleted {
  color: #79c0ff !important;
}

.token.selector,
.token.attr-name,
.token.string,
.token.char,
.token.builtin,
.token.inserted {
  color: #a5d6ff !important;
}

.token.operator,
.token.entity,
.token.url,
.language-css .token.string,
.style .token.string {
  color: #d2a8ff !important;
}

.token.atrule,
.token.attr-value,
.token.keyword {
  color: #ff7b72 !important;
}

.token.function,
.token.class-name {
  color: #d2a8ff !important;
}

.token.regex,
.token.important,
.token.variable {
  color: #ffa657 !important;
}

.token.important,
.token.bold {
  font-weight: bold !important;
}

.token.italic {
  font-style: italic !important;
}

.token.entity {
  cursor: help !important;
}

/* XML-specific tokens for HCDF examples */
.token.tag .token.tag {
  color: #7ee787 !important;
}
.token.tag .token.attr-name {
  color: #79c0ff !important;
}
.token.tag .token.attr-value {
  color: #a5d6ff !important;
}
.token.tag .token.punctuation {
  color: #8b949e !important;
}