/* Shader Lab — shared styles */

:root {
  --paper: #fbf4ea;
  --paper-warm: #f1e9dc;
  --paper-deep: #e9ded0;
  --ink: #2e2a3a;
  --muted: #6b6578;
  --muted-soft: #a09aab;
  --accent: #c46c54;
  --accent-dim: rgba(196,108,84,0.14);
  --accent-faint: rgba(196,108,84,0.06);
  --line: rgba(46,42,58,0.12);
  --line-strong: rgba(46,42,58,0.24);
  --code-bg: rgba(196,108,84,0.08);
  --code-fg: #8b3b2a;

  --sidebar-width: 260px;
  --sidebar-collapsed-width: 44px;

  --layer-coord: #4a7aa3;
  --layer-signal: #7a9a4c;
  --layer-color: #b66a8e;
}

* { box-sizing: border-box; margin: 0; padding: 0; }
html { scroll-behavior: smooth; }
body {
  background: var(--paper);
  color: var(--ink);
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "Helvetica Neue", sans-serif;
  font-size: 16.5px;
  line-height: 1.65;
  min-height: 100vh;
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
}

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

/* HEADER (on each lesson) */
header.lab-header {
  display: flex;
  align-items: baseline;
  justify-content: space-between;
  padding: 22px 32px;
  border-bottom: 1px solid var(--line);
  background: var(--paper);
  position: sticky;
  top: 0;
  z-index: 10;
  backdrop-filter: blur(8px);
  background-color: rgba(251, 244, 234, 0.92);
}
.lab-header .brand {
  font-family: "Bricolage Grotesque", Georgia, serif;
  font-size: 18px;
  font-weight: 600;
  letter-spacing: -0.01em;
}
.lab-header .brand a { color: inherit; }
.lab-header .brand a:hover { text-decoration: none; color: var(--accent); }
.lab-header .crumbs {
  font-size: 13px;
  color: var(--muted);
  display: flex;
  align-items: center;
  gap: 14px;
}
.lab-header .crumb-lesson {
  color: var(--ink);
  font-weight: 500;
}
.lab-header .crumb-lesson .num {
  color: var(--muted);
  font-variant-numeric: tabular-nums;
  margin-right: 6px;
}
.lab-header nav.prev-next {
  display: flex;
  gap: 6px;
}
.lab-header nav.prev-next a, .lab-header nav.prev-next span {
  display: inline-block;
  padding: 6px 12px;
  border: 1px solid var(--line);
  border-radius: 4px;
  font-size: 12.5px;
  color: var(--ink);
  text-decoration: none;
  transition: all 100ms ease;
  background: var(--paper-warm);
}
.lab-header nav.prev-next a:hover { background: var(--accent-dim); border-color: var(--accent); text-decoration: none; }
.lab-header nav.prev-next span { color: var(--muted-soft); background: transparent; cursor: default; }

/* MAIN LAYOUT */
main.lesson {
  max-width: 820px;
  margin: 0 auto;
  padding: 40px 32px 120px;
}

h1.lesson-title {
  font-family: "Bricolage Grotesque", Georgia, serif;
  font-size: 32px;
  font-weight: 600;
  letter-spacing: -0.015em;
  line-height: 1.15;
  margin-bottom: 6px;
}
.lesson-subtitle {
  font-size: 14px;
  color: var(--muted);
  letter-spacing: 0.04em;
  text-transform: uppercase;
  margin-bottom: 28px;
  font-weight: 500;
}

/* CANVAS AREA */
.canvas-wrap {
  position: relative;
  background: #0b0a12;
  border-radius: 8px;
  overflow: hidden;
  margin-bottom: 24px;
  box-shadow: 0 10px 30px -18px rgba(46,42,58,0.4);
  aspect-ratio: 16 / 9;
}
.canvas-wrap canvas {
  display: block;
  width: 100%;
  height: 100%;
  image-rendering: pixelated;
}

/* SLIDER PANEL */
.controls {
  display: grid;
  gap: 12px;
  padding: 18px 22px;
  background: var(--paper-warm);
  border: 1px solid var(--line);
  border-radius: 8px;
  margin-bottom: 36px;
}
.controls .control {
  display: grid;
  grid-template-columns: 110px 1fr 56px;
  align-items: center;
  gap: 14px;
}
.controls label {
  font-family: ui-monospace, "SF Mono", Menlo, monospace;
  font-size: 13px;
  color: var(--ink);
  font-weight: 500;
}
.controls .value {
  font-variant-numeric: tabular-nums;
  font-family: ui-monospace, "SF Mono", Menlo, monospace;
  font-size: 12px;
  color: var(--muted);
  text-align: right;
}
.controls input[type="range"] {
  -webkit-appearance: none;
  width: 100%;
  height: 4px;
  background: var(--paper-deep);
  border-radius: 2px;
  outline: none;
}
.controls input[type="range"]::-webkit-slider-thumb {
  -webkit-appearance: none;
  width: 18px;
  height: 18px;
  border-radius: 50%;
  background: var(--accent);
  border: 2px solid var(--paper);
  cursor: pointer;
  box-shadow: 0 1px 3px rgba(46,42,58,0.2);
  transition: transform 100ms ease;
}
.controls input[type="range"]:hover::-webkit-slider-thumb { transform: scale(1.15); }
.controls input[type="range"]::-moz-range-thumb {
  width: 18px;
  height: 18px;
  border-radius: 50%;
  background: var(--accent);
  border: 2px solid var(--paper);
  cursor: pointer;
}
.controls button.toggle {
  grid-column: 1 / -1;
  padding: 6px 14px;
  border: 1px solid var(--line);
  border-radius: 4px;
  background: var(--paper);
  color: var(--ink);
  font-size: 12px;
  cursor: pointer;
  font-family: inherit;
  transition: all 100ms ease;
  justify-self: start;
}
.controls button.toggle:hover { background: var(--accent-dim); border-color: var(--accent); }
.controls button.toggle[data-active="true"] { background: var(--accent); color: white; border-color: var(--accent); }

/* SECTION BLOCKS */
.block {
  margin-bottom: 28px;
}
.block > h3 {
  font-family: "Bricolage Grotesque", Georgia, serif;
  font-size: 15px;
  font-weight: 600;
  letter-spacing: 0.04em;
  text-transform: uppercase;
  color: var(--muted);
  margin-bottom: 8px;
}
.block p { margin-bottom: 10px; }
.block p:last-child { margin-bottom: 0; }

.block--insight {
  padding: 20px 24px;
  background: var(--accent-faint);
  border-left: 3px solid var(--accent);
  border-radius: 0 6px 6px 0;
}
.block--insight > h3 { color: var(--accent); }

.block--break {
  padding: 20px 24px;
  background: var(--paper-warm);
  border: 1px dashed var(--line-strong);
  border-radius: 6px;
}
.block--break > h3 { color: var(--ink); }
.block--break p { color: var(--ink); }
.block--break em { font-style: italic; color: var(--muted); }

.block--direct {
  padding: 20px 24px;
  background: white;
  border: 1px solid var(--line);
  border-radius: 6px;
}
.block--direct > h3 { color: var(--ink); }
.block--direct .verb-map {
  display: grid;
  grid-template-columns: auto 1fr;
  gap: 8px 18px;
  margin-top: 4px;
  font-size: 14.5px;
}
.block--direct .verb-map .phrase {
  font-style: italic;
  color: var(--ink);
}
.block--direct .verb-map .arrow { color: var(--muted-soft); }
.block--direct .verb-map .mapping {
  font-family: ui-monospace, "SF Mono", Menlo, monospace;
  font-size: 13px;
  color: var(--code-fg);
}
.block--direct .meta {
  margin-top: 18px;
  padding-top: 14px;
  border-top: 1px solid var(--line);
  font-size: 13.5px;
  color: var(--muted);
  font-style: italic;
}

/* LAYER STAMP */
.layer-stamp {
  display: inline-flex;
  gap: 6px;
  margin: 6px 0 18px;
  flex-wrap: wrap;
}
.layer-stamp .pill {
  display: inline-block;
  padding: 3px 10px;
  border-radius: 12px;
  font-size: 11.5px;
  font-weight: 600;
  letter-spacing: 0.05em;
  text-transform: uppercase;
  font-family: ui-monospace, "SF Mono", Menlo, monospace;
  color: white;
}
.layer-stamp .pill--coord { background: var(--layer-coord); }
.layer-stamp .pill--signal { background: var(--layer-signal); }
.layer-stamp .pill--color { background: var(--layer-color); }
.layer-stamp .pill.muted { opacity: 0.25; }

/* TEXT CONTENT */
p { margin: 0.7em 0; }
strong { font-weight: 600; }
em { font-style: italic; color: var(--muted); }
code {
  background: var(--code-bg);
  color: var(--code-fg);
  padding: 1.5px 6px;
  border-radius: 3px;
  font-family: ui-monospace, "SF Mono", Menlo, Consolas, monospace;
  font-size: 0.9em;
  font-weight: 500;
}

/* CODE TOGGLE BLOCK */
.code-block {
  margin-top: 32px;
  padding-top: 20px;
  border-top: 1px solid var(--line);
}
.code-block .toggle-row {
  display: flex;
  align-items: center;
  gap: 10px;
  margin-bottom: 12px;
}
.code-block button.code-toggle {
  padding: 6px 14px;
  border: 1px solid var(--line);
  border-radius: 4px;
  background: var(--paper-warm);
  color: var(--ink);
  font-size: 12px;
  font-family: inherit;
  cursor: pointer;
  transition: all 100ms ease;
}
.code-block button.code-toggle:hover { background: var(--accent-dim); border-color: var(--accent); }
.code-block .code-label {
  font-size: 12.5px;
  color: var(--muted);
  font-style: italic;
}
.code-block pre {
  background: #1a1823;
  color: #e8e3d3;
  border-radius: 6px;
  padding: 18px 22px;
  overflow-x: auto;
  font-family: ui-monospace, "SF Mono", Menlo, Consolas, monospace;
  font-size: 13px;
  line-height: 1.6;
  display: none;
}
.code-block pre.visible { display: block; }
.code-block pre .glsl-kw { color: #c46c54; }
.code-block pre .glsl-type { color: #9ab48a; }
.code-block pre .glsl-num { color: #e0b86e; }
.code-block pre .glsl-comment { color: #6b6578; font-style: italic; }

/* COMBINES-WITH FOOTER */
.combines {
  margin-top: 32px;
  padding-top: 18px;
  border-top: 1px solid var(--line);
  font-size: 13.5px;
  color: var(--muted);
}
.combines strong { color: var(--ink); font-weight: 600; }

/* RESPONSIVE */
@media (max-width: 680px) {
  header.lab-header { padding: 16px 20px; flex-wrap: wrap; gap: 8px; }
  main.lesson { padding: 28px 20px 80px; }
  h1.lesson-title { font-size: 26px; }
  .controls .control { grid-template-columns: 90px 1fr 50px; gap: 10px; }
  .lab-header .brand { font-size: 16px; }
}

/* INDEX / TOC PAGE */
.toc-page main {
  max-width: 900px;
  margin: 0 auto;
  padding: 64px 32px 120px;
}
.toc-page h1 {
  font-family: "Bricolage Grotesque", Georgia, serif;
  font-size: 44px;
  font-weight: 600;
  letter-spacing: -0.02em;
  margin-bottom: 8px;
}
.toc-page .tagline {
  font-size: 16px;
  color: var(--muted);
  margin-bottom: 40px;
  max-width: 600px;
  line-height: 1.55;
}
.toc-page .arc-section {
  margin-bottom: 36px;
  padding: 20px 24px;
  background: white;
  border: 1px solid var(--line);
  border-radius: 8px;
}
.toc-page .arc-section.disabled { opacity: 0.6; }
.toc-page .arc-label {
  font-size: 12px;
  font-weight: 700;
  letter-spacing: 0.12em;
  text-transform: uppercase;
  color: var(--accent);
  margin-bottom: 4px;
}
.toc-page .arc-title {
  font-family: "Bricolage Grotesque", Georgia, serif;
  font-size: 22px;
  font-weight: 600;
  letter-spacing: -0.005em;
  margin-bottom: 14px;
}
.toc-page .lesson-list {
  list-style: none;
  padding: 0;
}
.toc-page .lesson-list li {
  padding: 6px 0;
  border-bottom: 1px dotted var(--line);
}
.toc-page .lesson-list li:last-child { border-bottom: none; }
.toc-page .lesson-list a {
  display: grid;
  grid-template-columns: 40px 1fr auto;
  align-items: baseline;
  gap: 12px;
  color: var(--ink);
  padding: 4px 0;
  text-decoration: none;
  transition: color 100ms ease;
}
.toc-page .lesson-list a:hover { color: var(--accent); text-decoration: none; }
.toc-page .lesson-list .num {
  font-variant-numeric: tabular-nums;
  font-family: ui-monospace, monospace;
  font-size: 13px;
  color: var(--muted);
}
.toc-page .lesson-list .title { font-weight: 500; }
.toc-page .lesson-list .tags {
  font-size: 11.5px;
  color: var(--muted-soft);
  font-family: ui-monospace, monospace;
}
.toc-page .lesson-list li.coming-soon a {
  cursor: default;
  color: var(--muted-soft);
}
.toc-page .lesson-list li.coming-soon a:hover { color: var(--muted-soft); }
.toc-page .note {
  margin-top: 40px;
  padding: 16px 20px;
  background: var(--accent-faint);
  border-left: 3px solid var(--accent);
  border-radius: 0 6px 6px 0;
  font-size: 14px;
  color: var(--ink);
}

/* ═══════════════════════════════════════════════════════════════
   SIDEBAR NAVIGATION (injected by nav.js)
   ═══════════════════════════════════════════════════════════════ */

body.sl-has-sidebar { display: flex; min-height: 100vh; }

/* content wrapper (everything except sidebar) */
.sl-content {
  flex: 1;
  min-width: 0;
  display: flex;
  flex-direction: column;
  max-height: 100vh;
  overflow-y: auto;
}

/* sidebar container */
#sl-sidebar {
  width: var(--sidebar-width);
  min-width: var(--sidebar-width);
  height: 100vh;
  position: sticky;
  top: 0;
  background: var(--paper);
  border-right: 1px solid var(--line);
  display: flex;
  flex-direction: column;
  overflow: hidden;
  transition: width 200ms ease, min-width 200ms ease;
  z-index: 20;
}
#sl-sidebar.collapsed {
  width: var(--sidebar-collapsed-width);
  min-width: var(--sidebar-collapsed-width);
}
#sl-sidebar.collapsed .sl-sidebar-brand,
#sl-sidebar.collapsed .sl-sidebar-nav { display: none; }

/* wrapper for header + content after sidebar */
body.sl-has-sidebar > :not(#sl-sidebar) { /* handled by flex:1 above */ }

/* toggle button */
.sl-sidebar-toggle {
  flex-shrink: 0;
  display: flex;
  align-items: center;
  justify-content: center;
  width: 100%;
  height: 44px;
  border: none;
  border-bottom: 1px solid var(--line);
  background: transparent;
  color: var(--muted);
  cursor: pointer;
  transition: color 100ms ease, background 100ms ease;
}
.sl-sidebar-toggle:hover { background: var(--accent-faint); color: var(--accent); }

/* brand */
.sl-sidebar-brand {
  display: block;
  padding: 14px 18px 10px;
  font-family: "Bricolage Grotesque", Georgia, serif;
  font-size: 17px;
  font-weight: 600;
  color: var(--ink);
  text-decoration: none;
  letter-spacing: -0.01em;
  border-bottom: 1px solid var(--line);
}
.sl-sidebar-brand:hover { color: var(--accent); text-decoration: none; }
.sl-sidebar-brand.active { color: var(--accent); }

/* nav scroll area */
.sl-sidebar-nav {
  flex: 1;
  overflow-y: auto;
  padding: 10px 0 24px;
  scrollbar-width: thin;
  scrollbar-color: var(--line-strong) transparent;
}
.sl-sidebar-nav::-webkit-scrollbar { width: 5px; }
.sl-sidebar-nav::-webkit-scrollbar-thumb { background: var(--line-strong); border-radius: 3px; }

/* arc group header */
.sl-arc-header {
  display: flex;
  align-items: center;
  gap: 6px;
  width: 100%;
  padding: 10px 16px 6px;
  border: none;
  background: transparent;
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, sans-serif;
  font-size: 10.5px;
  font-weight: 700;
  letter-spacing: 0.1em;
  text-transform: uppercase;
  color: var(--accent);
  cursor: pointer;
  text-align: left;
}
.sl-arc-header:hover { color: var(--ink); }
.sl-arc-arrow {
  font-size: 10px;
  width: 12px;
  text-align: center;
  color: var(--muted-soft);
}

/* lesson links */
.sl-lesson-list { padding: 0; }
.sl-lesson-link {
  display: flex;
  align-items: baseline;
  gap: 8px;
  padding: 5px 16px 5px 18px;
  font-size: 13.5px;
  color: var(--ink);
  text-decoration: none;
  border-left: 3px solid transparent;
  transition: background 80ms ease, border-color 80ms ease, color 80ms ease;
  line-height: 1.35;
}
.sl-lesson-link:hover {
  background: var(--accent-faint);
  border-left-color: var(--muted-soft);
  text-decoration: none;
}
.sl-lesson-link.active {
  background: var(--accent-dim);
  border-left-color: var(--accent);
  color: var(--accent);
  font-weight: 600;
}
.sl-lesson-num {
  font-variant-numeric: tabular-nums;
  font-family: ui-monospace, monospace;
  font-size: 11px;
  color: var(--muted-soft);
  min-width: 20px;
}
.sl-lesson-link.active .sl-lesson-num { color: var(--accent); }

/* RESPONSIVE: hide sidebar on narrow screens, show overlay */
@media (max-width: 900px) {
  #sl-sidebar {
    position: fixed;
    left: 0; top: 0;
    height: 100vh;
    transform: translateX(-100%);
    transition: transform 200ms ease;
    box-shadow: none;
    z-index: 100;
  }
  body.sl-sidebar-open #sl-sidebar {
    transform: translateX(0);
    box-shadow: 4px 0 24px rgba(46,42,58,0.15);
  }
  #sl-sidebar.collapsed { transform: translateX(-100%); width: var(--sidebar-width); min-width: var(--sidebar-width); }
  #sl-sidebar.collapsed .sl-sidebar-brand,
  #sl-sidebar.collapsed .sl-sidebar-nav { display: block; }
  /* always show toggle on mobile */
  body.sl-has-sidebar .sl-sidebar-toggle {
    position: fixed;
    top: 8px; left: 8px;
    width: 36px; height: 36px;
    border-radius: 6px;
    background: var(--paper);
    border: 1px solid var(--line);
    z-index: 101;
    box-shadow: 0 2px 8px rgba(46,42,58,0.1);
  }
}

/* toc-page adjustments when sidebar is present */
body.toc-page.sl-has-sidebar > main { padding-top: 40px; }