/* ============================================================
   xpong — Shared Stylesheet
   Light (default) + Dark mode via [data-theme="dark"]
   ============================================================ */

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

/* --- CSS varijable --- */
:root {
  --bg:           #f8f9fa;
  --surface:      #ffffff;
  --border:       #a2a9b1;
  --border-light: #eaecf0;
  --text:         #202122;
  --text-muted:   #54595d;
  --text-light:   #72777d;
  --link:         #3366cc;
  --link-hover:   #6a8fd8;
  --accent:       #3366cc;
  --header-bg:    #ffffff;
  --toc-bg:       #f8f9fa;
  --infobox-head: #cee0f2;
  --badge-bg:     #eaecf0;
  --font-serif:   'Linux Libertine','Georgia','Times New Roman',serif;
  --font-sans:    'Linux Biolinum','Helvetica Neue',Arial,sans-serif;
  --font-mono:    'Courier New',monospace;
  --shadow:       0 1px 4px rgba(0,0,0,0.08);
}

[data-theme="dark"] {
  --bg:           #18191a;
  --surface:      #242526;
  --border:       #3a3b3c;
  --border-light: #2d2e2f;
  --text:         #e4e6ea;
  --text-muted:   #b0b3b8;
  --text-light:   #8a8d91;
  --link:         #7aabf7;
  --link-hover:   #aac8ff;
  --accent:       #7aabf7;
  --header-bg:    #242526;
  --toc-bg:       #1e1f20;
  --infobox-head: #2a3a5a;
  --badge-bg:     #3a3b3c;
  --shadow:       0 1px 4px rgba(0,0,0,0.4);
}

/* --- Base --- */
html { scroll-behavior: smooth; }
body {
  background: var(--bg);
  color: var(--text);
  font-family: var(--font-sans);
  font-size: 14px;
  line-height: 1.6;
  transition: background .2s, color .2s;
}
a { color: var(--link); text-decoration: none; }
a:hover { text-decoration: underline; color: var(--link-hover); }

/* --- Header --- */
#xp-header {
  background: var(--header-bg);
  border-bottom: 1px solid var(--border);
  padding: 8px 0;
  position: sticky;
  top: 0;
  z-index: 100;
  box-shadow: var(--shadow);
  transition: background .2s, border-color .2s;
}
#xp-header-inner {
  max-width: 1200px;
  margin: 0 auto;
  padding: 0 16px;
  display: flex;
  align-items: center;
  gap: 0;
}

/* Logo */
#xp-logo {
  font-family: var(--font-serif);
  font-size: 22px;
  font-weight: bold;
  color: var(--text);
  text-decoration: none;
  white-space: nowrap;
  margin-right: 24px;
}
#xp-logo span { color: var(--accent); }
#xp-logo:hover { text-decoration: none; }

/* Nav */
#xp-nav {
  display: flex;
  align-items: center;
  gap: 2px;
  flex: 1;
}
.xp-nav-link {
  padding: 4px 12px;
  border-radius: 3px;
  font-size: 13px;
  color: var(--text-muted);
  transition: background .15s, color .15s;
  white-space: nowrap;
}
.xp-nav-link:hover {
  background: var(--border-light);
  color: var(--text);
  text-decoration: none;
}
.xp-nav-link.active {
  background: var(--accent);
  color: #fff;
}

/* Header controls — desna strana */
#xp-header-controls {
  display: flex;
  align-items: center;
  gap: 12px;
  margin-left: auto;
}

/* Burger (mobile only) */
#xp-burger {
  display: none;
  background: none;
  border: 1px solid var(--border);
  border-radius: 3px;
  color: var(--text);
  font-size: 18px;
  padding: 2px 8px;
  cursor: pointer;
}

/* UI language dropdown */
#xp-lang-select {
  background: var(--bg);
  border: 1px solid var(--border);
  border-radius: 3px;
  padding: 2px 6px;
  font-size: 12px;
  color: var(--text-muted);
  cursor: pointer;
  outline: none;
}
#xp-lang-select:hover { border-color: var(--accent); }
#xp-lang-select:focus { border-color: var(--accent); }

/* Dark mode toggle */
#xp-theme-toggle {
  background: none;
  border: 1px solid var(--border);
  border-radius: 3px;
  padding: 3px 8px;
  cursor: pointer;
  font-size: 14px;
  color: var(--text-muted);
  transition: background .15s;
  line-height: 1;
}
#xp-theme-toggle:hover { background: var(--border-light); }

/* --- Page wrapper --- */
#xp-page {
  max-width: 1200px;
  margin: 0 auto;
  padding: 24px 16px;
}

/* --- Footer --- */
#xp-footer {
  border-top: 1px solid var(--border);
  background: var(--toc-bg);
  padding: 16px 0;
  margin-top: 48px;
  font-size: 12px;
  color: var(--text-light);
  text-align: center;
}
#xp-footer a { color: var(--text-light); }
#xp-footer a:hover { color: var(--link); }

.xp-prose pre { overflow-x: auto; }

/* --- Sidebar layout (za reader) --- */
.xp-layout-sidebar {
  display: grid;
  grid-template-columns: 220px 1fr;
  gap: 24px;
}

/* --- Surface box (sidebar, infobox...) --- */
.xp-box {
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: 2px;
  margin-bottom: 16px;
  overflow: hidden;
  transition: background .2s, border-color .2s;
}
.xp-box-title {
  background: var(--toc-bg);
  border-bottom: 1px solid var(--border);
  padding: 6px 12px;
  font-weight: bold;
  font-size: 13px;
  color: var(--text);
}
.xp-box-body { padding: 10px 12px; }

/* --- Main content panel --- */
.xp-main {
  min-width: 0;
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: 2px;
  padding: 24px 32px;
  transition: background .2s, border-color .2s;
}

/* --- Toggle switch --- */
.xp-toggle-wrap { display: flex; align-items: center; gap: 8px; font-size: 13px; }
.xp-toggle { position: relative; width: 36px; height: 18px; cursor: pointer; flex-shrink: 0; }
.xp-toggle input { opacity: 0; width: 0; height: 0; }
.xp-toggle-slider {
  position: absolute; inset: 0;
  background: var(--border);
  border-radius: 18px;
  transition: .2s;
}
.xp-toggle-slider::before {
  content: '';
  position: absolute;
  width: 12px; height: 12px;
  left: 3px; top: 3px;
  background: #fff;
  border-radius: 50%;
  transition: .2s;
}
.xp-toggle input:checked + .xp-toggle-slider { background: var(--accent); }
.xp-toggle input:checked + .xp-toggle-slider::before { transform: translateX(18px); }

/* --- Segmented control (tri vrednosti) --- */
.xp-seg-wrap { display: flex; align-items: center; justify-content: center; gap: 12px; margin: 16px auto 0; max-width: min(100%, 72vh); font-size: 13px; }
.xp-seg { display: flex; border: 1px solid var(--border); border-radius: 2px; overflow: hidden; }
.xp-seg-opt { position: relative; display: flex; cursor: pointer; }
.xp-seg-opt + .xp-seg-opt { border-left: 1px solid var(--border); }
.xp-seg-opt input { position: absolute; opacity: 0; width: 0; height: 0; }
.xp-seg-face { display: flex; flex-direction: column; align-items: center; gap: 2px; padding: 6px 16px; transition: background .2s, color .2s; }
.xp-seg-face em { font-style: normal; font-size: 12px; opacity: .7; }
.xp-seg-opt input:checked + .xp-seg-face { background: var(--accent); color: #fff; }
.xp-seg-opt input:checked + .xp-seg-face em { opacity: .9; }
.xp-seg-opt input:focus-visible + .xp-seg-face { outline: 2px solid var(--accent); outline-offset: -2px; }

/* --- Training chart + indicators (rl2) --- */
.xp-chart-wrap { max-width: min(100%, 72vh); margin: 20px auto 0; }
.xp-chart-wrap canvas { width: 100%; height: auto; display: block; border: 1px solid var(--border); border-radius: 2px; background: var(--surface); }
.xp-stats { display: flex; justify-content: space-around; gap: 12px; margin-top: 10px; font-size: 13px; flex-wrap: wrap; }
.xp-stat { text-align: center; min-width: 90px; }
.xp-stat b { display: block; font-size: 18px; font-weight: 600; color: var(--accent); }
.xp-stat span { color: var(--text-muted); }
.xp-chart-title { font-size: 15px; font-weight: 600; text-align: center; margin: 0 0 8px; }
.xp-chart-caption { font-size: 12px; color: var(--text-muted); text-align: center; margin: 10px 0 0; }

/* --- Infobox (Wikipedia stil) --- */
.xp-infobox {
  float: right;
  clear: right;
  margin: 0 0 16px 24px;
  background: var(--toc-bg);
  border: 1px solid var(--border);
  border-radius: 2px;
  font-size: 12px;
  width: 220px;
}
.xp-infobox-title {
  background: var(--infobox-head);
  text-align: center;
  font-weight: bold;
  padding: 4px 8px;
  font-size: 13px;
}
.xp-infobox table { width: 100%; border-collapse: collapse; }
.xp-infobox td { padding: 3px 8px; vertical-align: top; }
.xp-infobox td:first-child { font-weight: bold; color: var(--text-muted); width: 80px; }
.xp-infobox tr { border-bottom: 1px solid var(--border-light); }
.xp-infobox tr:last-child { border-bottom: none; }

/* --- Badge --- */
.xp-badge {
  display: inline-block;
  background: var(--badge-bg);
  color: var(--text-muted);
  font-size: 11px;
  font-family: var(--font-mono);
  padding: 1px 6px;
  border-radius: 2px;
  border: 1px solid var(--border-light);
}
.xp-badge-coming-soon {
  background: none;
  color: var(--text-light);
  border-color: var(--border-light);
  font-style: italic;
}

/* --- Buttons --- */
.xp-btn {
  display: inline-block;
  padding: 5px 14px;
  border-radius: 3px;
  border: 1px solid var(--border);
  font-size: 13px;
  cursor: pointer;
  background: var(--surface);
  color: var(--text);
  transition: background .15s;
  text-decoration: none;
}
.xp-btn:hover { background: var(--border-light); text-decoration: none; }
.xp-btn-primary {
  background: var(--accent);
  color: #fff;
  border-color: var(--accent);
}
.xp-btn-primary:hover { opacity: 0.9; background: var(--accent); color: #fff; }
.xp-btn-disabled {
  opacity: 0.45;
  cursor: not-allowed;
  pointer-events: none;
}

/* --- Hero (landing page) --- */
.xp-hero {
  text-align: center;
  padding: 56px 24px 48px;
  border-bottom: 1px solid var(--border-light);
  margin-bottom: 40px;
}
.xp-hero-logo {
  font-family: var(--font-serif);
  font-size: 52px;
  font-weight: bold;
  color: var(--text);
  margin-bottom: 8px;
  letter-spacing: -1px;
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 16px;
}
.xp-hero-icon { width: 64px; height: 64px; flex-shrink: 0; }
.xp-hero-logo span { color: var(--accent); }
.xp-hero-lab {
  font-size: 12px;
  font-weight: 600;
  letter-spacing: 2px;
  text-transform: uppercase;
  color: var(--accent);
  margin-bottom: 14px;
}
.xp-hero-tagline {
  font-size: 16px;
  color: var(--text-muted);
  margin-bottom: 32px;
  font-style: italic;
}
.xp-hero-desc {
  max-width: 680px;
  margin: 0 auto 36px;
  font-size: 15px;
  line-height: 1.8;
  color: var(--text);
  font-family: var(--font-serif);
}
.xp-hero-actions {
  display: flex;
  justify-content: center;
  gap: 12px;
  flex-wrap: wrap;
}

/* --- Cards (books.html) --- */
.xp-cards {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(280px, 1fr));
  gap: 20px;
  margin-top: 24px;
}
.xp-card {
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: 3px;
  overflow: hidden;
  transition: box-shadow .15s, background .2s;
}
.xp-card:hover { box-shadow: 0 2px 8px rgba(0,0,0,0.12); }
.xp-card-head {
  background: var(--toc-bg);
  border-bottom: 1px solid var(--border);
  padding: 10px 14px;
}
.xp-card-title {
  font-family: var(--font-serif);
  font-size: 16px;
  font-weight: bold;
  color: var(--text);
  margin-bottom: 2px;
}
.xp-card-author { font-size: 12px; color: var(--text-muted); }
.xp-card-body { padding: 12px 14px; }
.xp-card-meta { font-size: 12px; color: var(--text-light); margin-bottom: 10px; }
.xp-card-langs {
  display: flex;
  flex-wrap: wrap;
  gap: 4px;
  margin-bottom: 14px;
}
.xp-card-actions {
  display: flex;
  flex-wrap: wrap;
  gap: 6px;
  border-top: 1px solid var(--border-light);
  padding-top: 10px;
}

/* --- Section headings --- */
#about-layout { display: grid; grid-template-columns: 1fr 280px; gap: 32px; align-items: start; }
.xp-infobox-text { font-size: 13px; line-height: 1.7; color: var(--text-muted); margin: 0; padding: 8px; }

.xp-section-title {
  font-family: var(--font-serif);
  font-size: 22px;
  font-weight: normal;
  border-bottom: 1px solid var(--border);
  padding-bottom: 4px;
  margin-bottom: 16px;
  color: var(--text);
}
.xp-section-subtitle {
  font-size: 13px;
  color: var(--text-muted);
  margin-top: -12px;
  margin-bottom: 20px;
}

/* --- Prose (about.html) --- */
.xp-prose {
  font-family: var(--font-serif);
  font-size: 16px;
  line-height: 1.8;
  color: var(--text);
  max-width: 760px;
}
.xp-prose h2 {
  font-size: 20px;
  font-weight: normal;
  border-bottom: 1px solid var(--border-light);
  padding-bottom: 3px;
  margin: 28px 0 12px;
}
.xp-prose h3 {
  font-size: 16px;
  font-weight: bold;
  margin: 20px 0 8px;
}
.xp-prose p { margin-bottom: 12px; }
.xp-prose code {
  font-family: var(--font-mono);
  font-size: 13px;
  background: var(--toc-bg);
  border: 1px solid var(--border-light);
  padding: 0 4px;
  border-radius: 2px;
}
.xp-prose pre {
  background: var(--toc-bg);
  border: 1px solid var(--border);
  border-radius: 2px;
  padding: 12px 16px;
  overflow-x: auto;
  margin-bottom: 16px;
}
.xp-prose pre code { background: none; border: none; padding: 0; }
.xp-prose table { border-collapse: collapse; width: 100%; margin-bottom: 16px; font-size: 14px; }
.xp-prose th { background: var(--toc-bg); text-align: left; padding: 6px 10px; border: 1px solid var(--border); }
.xp-prose td { padding: 5px 10px; border: 1px solid var(--border-light); }

/* --- Stats (stats.html) --- */
.xp-stats-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(200px, 1fr));
  gap: 16px;
  margin-bottom: 32px;
}
.xp-stat-card {
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: 2px;
  padding: 16px;
  text-align: center;
}
.xp-stat-number {
  font-family: var(--font-serif);
  font-size: 36px;
  font-weight: bold;
  color: var(--accent);
  line-height: 1.1;
}
.xp-stat-label {
  font-size: 12px;
  color: var(--text-muted);
  margin-top: 4px;
}

/* --- Loading / empty states --- */
.xp-loading {
  text-align: center;
  padding: 60px 0;
  color: var(--text-muted);
  font-size: 16px;
}


/* --- Key Concepts --- */
#xp-key-concepts {
  max-width: 1200px;
  margin: 0 auto;
  padding: 24px 16px 32px;
}
.xp-concepts-title {
  font-size: 12px;
  font-weight: 700;
  letter-spacing: 0.1em;
  text-transform: uppercase;
  color: var(--text-muted);
  border-top: 1px solid var(--border);
  padding-top: 20px;
  margin-bottom: 16px;
}
.xp-concepts-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(260px, 1fr));
  gap: 10px;
}
.xp-concept-card {
  display: flex;
  align-items: flex-start;
  gap: 10px;
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: 8px;
  padding: 12px 14px;
}
.xp-concept-icon { font-size: 18px; flex-shrink: 0; margin-top: 2px; }
.xp-concept-body { display: flex; flex-direction: column; gap: 4px; }
.xp-concept-name {
  font-weight: 600;
  font-size: 13px;
  color: var(--link);
  text-decoration: none;
}
.xp-concept-name:hover { text-decoration: underline; color: var(--link-hover); }
.xp-concept-desc { font-size: 12px; color: var(--text-muted); line-height: 1.5; }

/* --- Responsive --- */
@media (max-width: 700px) {
  .xp-layout-sidebar { grid-template-columns: 1fr; }
  #about-layout { grid-template-columns: 1fr !important; }
  .xp-prose table { display: block; overflow-x: auto; }
  .xp-main { padding: 16px; }
  .xp-hero-logo { font-size: 36px; }
  .xp-hero { padding: 32px 16px 28px; }
  #xp-nav { display: none; }
  #xp-burger { display: block; padding: 4px 12px; font-size: 20px; }
  #xp-logo { font-size: 17px; margin-right: 8px; }
  #xp-lang-select { font-size: 11px; }
  #xp-header-controls { gap: 5px; }
  #xp-header-inner { padding: 0 8px; }
  #xp-nav.open {
    display: flex;
    flex-direction: column;
    position: absolute;
    top: 100%;
    left: 0;
    right: 0;
    background: var(--header-bg);
    border-bottom: 1px solid var(--border);
    box-shadow: var(--shadow);
    padding: 8px 16px;
    gap: 4px;
  }
  #xp-nav.open .xp-nav-link { padding: 10px 12px; font-size: 15px; }
  #xp-header-inner { position: relative; }
}

/* --- M1: Pong game --- */
.xp-game-wrap {
  max-width: 1200px;
  margin: 0 auto;
}
.xp-game-scorebar {
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 28px;
  margin: 4px 0 10px;
  font-family: var(--font-mono);
}

.xp-game-winner {
  text-align: center;
  min-height: 22px;
  margin: -4px 0 10px;
  font-family: var(--font-mono);
  font-size: 20px;
  font-weight: bold;
  color: var(--accent);
  letter-spacing: 0.5px;
}
.xp-game-score {
  font-size: 36px;
  font-weight: bold;
  color: var(--text);
  min-width: 60px;
  text-align: center;
  line-height: 1;
}
.xp-game-score-label {
  display: inline;
  margin-right: 8px;
  font-family: var(--font-sans);
  font-size: 12px;
  font-weight: normal;
  color: var(--text-muted);
  text-transform: uppercase;
  letter-spacing: 1px;
  margin-bottom: 0;
}
.xp-game-score-sep {
  font-size: 32px;
  color: var(--text-light);
}
.xp-game-canvas-box {
  position: relative;
  max-width: min(100%, 72vh);
  margin: 0 auto;
  border: 2px solid var(--border);
  border-radius: 6px;
  overflow: hidden;
  background: var(--surface);
  line-height: 0;
}
.xp-state-table {
  display: flex;
  flex-wrap: wrap;
  justify-content: center;
  align-items: stretch;
  gap: 4px;
  margin: 0 0 10px;
  font-family: var(--font-mono);
}
.xp-state-head {
  width: 100%;
  text-align: center;
  color: var(--text);
  font-weight: 600;
  font-size: 13px;
  margin-bottom: 2px;
}
.xp-state-row {
  display: flex;
  flex-direction: column;
  align-items: center;
  min-width: 76px;
  padding: 4px 8px;
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: 4px;
}
.xp-state-row span { font-size: 11px; color: var(--text-muted); }
.xp-state-row b { font-size: 14px; color: var(--text); font-weight: 600; }
.xp-state-out { opacity: 0.6; border-left: 2px dashed var(--border); margin-left: 6px; }
#xp-game {
  display: block;
  touch-action: none;
  width: 100%;
  height: auto;
}
.xp-game-status {
  text-align: center;
  min-height: 22px;
  margin: 12px 0;
  color: var(--text-muted);
  font-size: 14px;
}
.xp-game-controls {
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 12px;
  margin: 8px 0 24px;
}
.xp-controls-row {
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 12px;
  flex-wrap: wrap;
}
.xp-game-btn {
  font-family: var(--font-sans);
  font-size: 15px;
  padding: 10px 24px;
  border: 1px solid var(--border);
  border-radius: 4px;
  background: var(--surface);
  color: var(--text);
  cursor: pointer;
  transition: background .15s, border-color .15s;
}
.xp-game-btn:hover {
  border-color: var(--accent);
  color: var(--accent);
}
.xp-game-btn-primary {
  background: var(--accent);
  color: #fff;
  border-color: var(--accent);
  min-width: 130px;
}
.xp-game-btn-primary:hover {
  background: var(--link-hover);
  color: #fff;
}
.xp-game-btn-active {
  border-color: var(--accent);
  color: var(--accent);
  box-shadow: inset 0 0 0 1px var(--accent);
}
.xp-xray-intro {
  max-width: 720px;
  margin: 0 auto 18px;
  text-align: center;
  color: var(--text-muted);
  font-size: 14px;
  line-height: 1.5;
}
#xray-layout {
  display: grid;
  grid-template-columns: 1fr 280px;
  gap: 28px;
  align-items: start;
}
.xray-main { min-width: 0; }
.xp-xray-box {
  float: none;
  width: auto;
  margin: 0;
  position: sticky;
  top: 16px;
}
.xray-side { display: flex; flex-direction: column; gap: 16px; }
.xray-side .xp-infobox { width: auto; margin: 0; float: none; }
.xp-game-deck {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 16px;
  max-width: min(100%, 72vh);
  margin: 8px auto 24px;
  font-size: 13px;
  color: var(--text-muted);
}
.xp-game-deck-center {
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 4px;
  flex: 0 0 auto;
}
.xp-game-deck .xp-game-legend-side {
  flex: 0 1 240px;
}
/* status/controls sit inside the deck centre now — drop their outer margins */
.xp-game-deck .xp-game-status   { margin: 0 0 4px; }
.xp-game-deck .xp-game-controls { margin: 0; }
.xp-game-legend-side {
  flex: 1;
  text-align: center;
  padding: 10px;
  border: 1px solid var(--border-light);
  border-radius: 6px;
}
.xp-keys { margin-top: 6px; font-size: 18px; font-weight: 700; letter-spacing: 1px; }
.xp-game-legend-side strong {
  color: var(--text);
  display: block;
  margin-bottom: 4px;
}
.xp-game-legend kbd {
  font-family: var(--font-mono);
  font-size: 12px;
  background: var(--badge-bg);
  border: 1px solid var(--border);
  border-radius: 3px;
  padding: 1px 6px;
  margin: 0 1px;
}

/* --- M1: Pong game — mobile --- */
@media (max-width: 700px) {
  .xp-game-score { font-size: 36px; }
  .xp-game-scorebar { gap: 20px; }
  #xray-layout { grid-template-columns: 1fr; }
  .xp-game-deck { flex-direction: column; gap: 12px; }
  .xp-game-deck-center { order: -1; }
  .xp-game-deck .xp-game-legend-side { flex: 1 1 auto; width: 100%; }
  .xp-game-controls { flex-wrap: wrap; }
}