/* ============================================================
   SFrontiers.jl User Manual — Professional Stylesheet
   ============================================================ */

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

:root {
  --primary:       #2e63b8;
  --primary-light: #4a90d9;
  --primary-bg:    #f0f4fa;
  --accent:        #4eb5de;
  --text:          #222222;
  --text-light:    #555555;
  --bg:            #ffffff;
  --sidebar-bg:    #f6f8fa;
  --sidebar-w:     18rem;
  --border:        #dbdbdb;
  --border-light:  #e8eaed;
  --code-bg:       #f6f8fa;
  --code-border:   #e1e4e8;
  --success:       #22c35b;
  --warning:       #e8a317;
  --danger:        #da0b00;
  --radius:        6px;
  --shadow:        0 1px 3px rgba(0,0,0,0.08);
  --shadow-lg:     0 4px 12px rgba(0,0,0,0.1);
  --transition:    0.25s ease;
}

html {
  scroll-behavior: smooth;
  scroll-padding-top: 5rem;
}

body {
  margin: 0;
  padding: 0;
  font-family: "Lato", -apple-system, BlinkMacSystemFont, "Segoe UI",
               Roboto, "Helvetica Neue", Arial, sans-serif;
  font-size: 16px;
  line-height: 1.65;
  color: var(--text);
  background: var(--bg);
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
}

/* --- Top Navbar --- */
.top-navbar {
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  height: 3.5rem;
  background: var(--bg);
  border-bottom: 1px solid var(--border);
  z-index: 100;
  box-shadow: var(--shadow);
}

.navbar-inner {
  max-width: 100%;
  height: 100%;
  display: flex;
  align-items: center;
  padding: 0 1.25rem;
}

.navbar-brand a {
  font-size: 1.15rem;
  font-weight: 700;
  color: var(--primary);
  text-decoration: none;
  letter-spacing: -0.02em;
}

.navbar-links {
  margin-left: auto;
  display: flex;
  align-items: center;
  gap: 1rem;
}

.navbar-links a {
  display: flex;
  align-items: center;
  gap: 0.4rem;
  color: var(--text-light);
  text-decoration: none;
  font-size: 0.9rem;
  font-weight: 400;
  transition: color var(--transition);
}
.navbar-links a:hover { color: var(--primary); }
.navbar-links svg { flex-shrink: 0; }

/* Hamburger */
.sidebar-toggle {
  display: none;
  flex-direction: column;
  justify-content: center;
  gap: 4px;
  background: none;
  border: none;
  cursor: pointer;
  padding: 0.5rem;
  margin-right: 0.75rem;
}
.sidebar-toggle span {
  display: block;
  width: 20px;
  height: 2px;
  background: var(--text);
  border-radius: 2px;
  transition: var(--transition);
}

/* --- Sidebar --- */
.sidebar {
  position: fixed;
  top: 3.5rem;
  left: 0;
  bottom: 0;
  width: var(--sidebar-w);
  background: var(--sidebar-bg);
  border-right: 1px solid var(--border);
  overflow-y: auto;
  z-index: 50;
  display: flex;
  flex-direction: column;
  transition: transform var(--transition);
}

.sidebar-header {
  padding: 1rem 1.25rem;
  border-bottom: 1px solid var(--border);
  text-align: center;
}

.sidebar-logo {
  display: block;
  margin: 0 auto 0.5rem;
}

.sidebar-logo img {
  max-height: 6rem;
  width: auto;
  display: block;
  margin: 0 auto;
}

.sidebar-tagline {
  font-size: 0.82rem;
  font-weight: 900;
  color: var(--text);
  line-height: 1.3;
}

/* Search */
.sidebar-search {
  padding: 0.6rem 1rem;
  border-bottom: 1px solid var(--border-light);
}

.sidebar-search input {
  width: 100%;
  padding: 0.4rem 0.6rem;
  border: 1px solid var(--border);
  border-radius: 4px;
  font-size: 0.85rem;
  font-family: inherit;
  background: var(--bg);
  color: var(--text);
  outline: none;
  transition: border-color var(--transition), box-shadow var(--transition);
}
.sidebar-search input:focus {
  border-color: var(--primary-light);
  box-shadow: 0 0 0 2px rgba(74,144,217,0.15);
}
.sidebar-search input::placeholder { color: #aaa; }

/* Sidebar nav */
.sidebar-nav {
  flex: 1;
  overflow-y: auto;
  padding: 0.5rem 0;
}

.sidebar-nav ul {
  list-style: none;
  margin: 0;
  padding: 0;
}

.sidebar-nav > ul > li {
  margin: 0;
}

.sidebar-nav > ul > li > a {
  display: block;
  padding: 0.45rem 1.25rem;
  font-size: 0.9rem;
  font-weight: 700;
  color: var(--text);
  text-decoration: none;
  border-left: 3px solid transparent;
  transition: background var(--transition), border-color var(--transition), color var(--transition);
}

.sidebar-nav > ul > li > a:hover {
  background: rgba(46,99,184,0.06);
  color: var(--primary);
}

.sidebar-nav > ul > li > a.active {
  border-left-color: var(--primary);
  color: var(--primary);
  background: rgba(46,99,184,0.08);
}

/* Nested items */
.sidebar-nav ul ul {
  padding-left: 0;
}

.sidebar-nav ul ul a {
  display: block;
  padding: 0.3rem 1.25rem 0.3rem 2rem;
  font-size: 0.84rem;
  font-weight: 400;
  color: var(--text-light);
  text-decoration: none;
  border-left: 3px solid transparent;
  transition: background var(--transition), color var(--transition);
}

.sidebar-nav ul ul a:hover {
  color: var(--primary);
  background: rgba(46,99,184,0.04);
}

.sidebar-nav ul ul a.active {
  color: var(--primary);
  border-left-color: var(--primary-light);
  font-weight: 600;
}

/* Third-level */
.sidebar-nav ul ul ul a {
  padding-left: 2.8rem;
  font-size: 0.82rem;
}

/* Collapsible toggles */
.toc-toggle {
  display: inline-block;
  width: 1.1em;
  font-size: 0.65em;
  color: var(--text-light);
  cursor: pointer;
  text-align: center;
  transition: color var(--transition);
  vertical-align: middle;
  margin-right: 0.15em;
}
.toc-toggle:hover { color: var(--primary); }

/* Sidebar footer */
.sidebar-footer {
  padding: 0.75rem 1.25rem;
  border-top: 1px solid var(--border);
  display: flex;
  align-items: center;
  justify-content: space-between;
  font-size: 0.78rem;
  color: var(--text-light);
  flex-shrink: 0;
}

.version-badge {
  background: var(--primary);
  color: #fff;
  padding: 0.15em 0.5em;
  border-radius: 3px;
  font-size: 0.78rem;
  font-weight: 700;
}

/* Sidebar scrollbar */
.sidebar-nav::-webkit-scrollbar { width: 4px; }
.sidebar-nav::-webkit-scrollbar-thumb { background: #ccc; border-radius: 4px; }
.sidebar-nav::-webkit-scrollbar-thumb:hover { background: #aaa; }

/* --- Main Content --- */
.content {
  margin-left: var(--sidebar-w);
  margin-top: 3.5rem;
  padding: 2rem 2.5rem 3rem;
  max-width: 54rem;
  min-height: calc(100vh - 3.5rem);
}

/* --- Typography --- */
h1, h2, h3, h4, h5, h6 {
  color: var(--text);
  font-weight: 700;
  line-height: 1.3;
  margin-top: 2rem;
  margin-bottom: 0.75rem;
}

h1 {
  font-size: 2rem;
  font-weight: 900;
  color: var(--primary);
  border-bottom: 2px solid var(--primary);
  padding-bottom: 0.4rem;
  margin-top: 0;
}

h2 {
  font-size: 1.55rem;
  border-bottom: 1px solid var(--border);
  padding-bottom: 0.35rem;
}

h3 {
  font-size: 1.25rem;
  color: #1a1a2e;
}

h4 {
  font-size: 1.05rem;
  color: #333;
}

p { margin: 0.75rem 0; }

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

strong { font-weight: 700; }

hr {
  border: none;
  border-top: 1px solid var(--border);
  margin: 2.5rem 0;
}

/* --- Lists --- */
ul, ol {
  padding-left: 1.6rem;
  margin: 0.6rem 0;
}
li { margin: 0.3rem 0; }
li > ul, li > ol { margin: 0.2rem 0; }

/* --- Code --- */
code, pre {
  font-family: Consolas, "DejaVu Sans Mono", "Liberation Mono",
               "Courier New", monospace;
  font-size: 0.875em;
  font-variant-ligatures: no-contextual;
}

/* Inline code */
:not(pre) > code {
  background: var(--code-bg);
  border: 1px solid var(--code-border);
  padding: 0.12em 0.35em;
  border-radius: 4px;
  color: #c7254e;
  font-size: 0.85em;
}

/* Code blocks */
pre {
  background: var(--code-bg);
  border: 1px solid var(--code-border);
  border-radius: var(--radius);
  padding: 1rem 1.25rem;
  overflow-x: auto;
  line-height: 1.5;
  margin: 1rem 0;
  box-shadow: inset 0 1px 2px rgba(0,0,0,0.04);
}

pre code {
  background: none;
  border: none;
  padding: 0;
  color: inherit;
  font-size: 0.875em;
}

div.sourceCode {
  margin: 1rem 0;
  position: relative;
}

/* --- Tables --- */
table {
  border-collapse: collapse;
  width: 100%;
  margin: 1.25rem 0;
  font-size: 0.93em;
  box-shadow: var(--shadow);
  border-radius: var(--radius);
  overflow: hidden;
}

thead {
  background: var(--primary);
  color: #fff;
}

th {
  padding: 0.65rem 0.85rem;
  text-align: left;
  font-weight: 700;
  font-size: 0.88em;
  letter-spacing: 0.02em;
}

td {
  padding: 0.55rem 0.85rem;
  border-bottom: 1px solid var(--border-light);
}

tbody tr:nth-child(even) { background: #f9fafb; }
tbody tr:hover { background: var(--primary-bg); }

/* --- Blockquotes / Admonitions --- */
blockquote {
  margin: 1.25rem 0;
  padding: 0.85rem 1.25rem;
  border-left: 4px solid var(--primary);
  background: var(--primary-bg);
  border-radius: 0 var(--radius) var(--radius) 0;
  color: var(--text);
}
blockquote p { margin: 0.4rem 0; }
blockquote p:first-child strong {
  color: var(--primary);
}

/* --- Math --- */
.math.display {
  overflow-x: auto;
  padding: 0.5rem 0;
}

mjx-container[display="true"] {
  margin: 0.75em 0 !important;
  overflow-x: auto;
  overflow-y: hidden;
  padding: 0.25rem 0;
}

/* --- Page Footer --- */
.page-footer {
  margin-top: 3rem;
  padding-top: 0;
  text-align: center;
  font-size: 0.85rem;
  color: var(--text-light);
}
.page-footer hr {
  margin-bottom: 1.5rem;
}
.page-footer a {
  color: var(--primary);
}

/* --- Back to Top --- */
.back-to-top {
  position: fixed;
  bottom: 2rem;
  right: 2rem;
  width: 2.8rem;
  height: 2.8rem;
  border-radius: 50%;
  background: var(--primary);
  color: #fff;
  border: none;
  font-size: 1.4rem;
  cursor: pointer;
  box-shadow: var(--shadow-lg);
  opacity: 0;
  visibility: hidden;
  transition: opacity var(--transition), visibility var(--transition),
              background var(--transition), transform var(--transition);
  z-index: 90;
  display: flex;
  align-items: center;
  justify-content: center;
  line-height: 1;
}
.back-to-top.visible {
  opacity: 1;
  visibility: visible;
}
.back-to-top:hover {
  background: var(--primary-light);
  transform: translateY(-2px);
}

/* --- Sidebar Overlay (mobile) --- */
.sidebar-overlay {
  display: none;
  position: fixed;
  inset: 0;
  background: rgba(0,0,0,0.4);
  z-index: 40;
  opacity: 0;
  transition: opacity var(--transition);
}
.sidebar-overlay.visible {
  display: block;
  opacity: 1;
}

/* --- Title block header (pandoc) --- */
header#title-block-header {
  display: none;  /* Title is shown in sidebar instead */
}

/* --- Responsive: Tablet & Mobile --- */
@media (max-width: 1055px) {
  .sidebar {
    transform: translateX(-100%);
  }
  .sidebar.open {
    transform: translateX(0);
    box-shadow: var(--shadow-lg);
  }
  .sidebar-toggle {
    display: flex;
  }
  .content {
    margin-left: 0;
    padding: 1.5rem 1.25rem 2rem;
  }
}

@media (max-width: 600px) {
  h1 { font-size: 1.5rem; }
  h2 { font-size: 1.3rem; }
  h3 { font-size: 1.1rem; }
  .content { padding: 1.25rem 1rem 2rem; }
  pre { padding: 0.75rem; font-size: 0.82em; }
  table { font-size: 0.85em; }
  th, td { padding: 0.4rem 0.6rem; }
  .back-to-top { bottom: 1.2rem; right: 1.2rem; width: 2.4rem; height: 2.4rem; font-size: 1.2rem; }
}

/* --- Print --- */
@media print {
  .top-navbar, .sidebar, .sidebar-overlay, .back-to-top { display: none !important; }
  .content { margin-left: 0; padding: 0; max-width: 100%; }
  body { font-size: 11pt; }
  h1, h2, h3 { page-break-after: avoid; }
  pre, table { page-break-inside: avoid; }
  a { color: var(--text); text-decoration: underline; }
  a[href^="http"]::after { content: " (" attr(href) ")"; font-size: 0.8em; color: #666; }
}

/* Syntax highlighting is handled by highlight.js CDN */