/* ================================================================
   TeqStudy — Godot Course Stylesheet
   Aesthetic: "engine console" — dark editor chrome, blueprint grid,
   monospace structural labels, warm signal-amber for callouts.
   Distinct from cream/serif and pure-black/acid-green defaults.
   ================================================================ */

:root {
  --bg:        #14181f;   /* deep editor slate            */
  --bg-panel:  #1b2029;   /* raised panel                 */
  --bg-code:   #0f1319;   /* code well                    */
  --line:      #2a3340;   /* hairline / grid              */
  --ink:       #d7dee8;   /* primary text                 */
  --ink-dim:   #8492a6;   /* secondary text               */
  --ink-faint: #566072;   /* captions, line numbers       */
  --blue:      #4a8fe7;   /* Godot signal blue            */
  --blue-soft: #6ba7f0;
  --amber:     #e8b24a;   /* warnings / "do this" signal  */
  --green:     #5cc98b;   /* success / result             */
  --red:       #e56b6f;   /* errors / gotchas             */
  --violet:    #a988e0;   /* 3D accent                    */

  --mono: "SF Mono", "JetBrains Mono", "Fira Code", ui-monospace, "Cascadia Code", Menlo, Consolas, monospace;
  --sans: "Inter", -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, sans-serif;

  --maxw: 860px;
  --radius: 8px;
}

* { box-sizing: border-box; }

html { scroll-behavior: smooth; }

body {
  margin: 0;
  background: var(--bg);
  /* faint blueprint grid */
  background-image:
    linear-gradient(var(--line) 1px, transparent 1px),
    linear-gradient(90deg, var(--line) 1px, transparent 1px);
  background-size: 44px 44px;
  background-position: -1px -1px;
  color: var(--ink);
  font-family: var(--sans);
  font-size: 17px;
  line-height: 1.68;
  -webkit-font-smoothing: antialiased;
}

.wrap {
  max-width: var(--maxw);
  margin: 0 auto;
  padding: 0 22px 120px;
}

/* ---------- top bar ---------- */
.topbar {
  position: sticky; top: 0; z-index: 50;
  background: rgba(20,24,31,0.92);
  backdrop-filter: blur(8px);
  border-bottom: 1px solid var(--line);
  font-family: var(--mono);
  font-size: 13px;
}
.topbar-inner {
  max-width: var(--maxw);
  margin: 0 auto;
  padding: 11px 22px;
  display: flex; align-items: center; gap: 14px;
  color: var(--ink-dim);
}
.topbar .brand { color: var(--blue); font-weight: 600; letter-spacing: .04em; }
.topbar .sep { color: var(--ink-faint); }
.topbar a { color: var(--ink-dim); text-decoration: none; }
.topbar a:hover { color: var(--ink); }
.topbar .right { margin-left: auto; }

/* ---------- lesson header ---------- */
.lesson-head {
  padding: 54px 0 26px;
  border-bottom: 1px solid var(--line);
  margin-bottom: 40px;
}
.eyebrow {
  font-family: var(--mono);
  font-size: 12.5px;
  letter-spacing: .16em;
  text-transform: uppercase;
  color: var(--blue);
  margin: 0 0 14px;
  display: flex; align-items: center; gap: 10px;
}
.eyebrow .dot { width: 6px; height: 6px; border-radius: 50%; background: var(--blue); box-shadow: 0 0 10px var(--blue); }
.track-3d .eyebrow { color: var(--violet); }
.track-3d .eyebrow .dot { background: var(--violet); box-shadow: 0 0 10px var(--violet); }

h1 {
  font-size: 40px;
  line-height: 1.12;
  letter-spacing: -0.02em;
  margin: 0 0 16px;
  font-weight: 700;
}
.lesson-head .lede {
  font-size: 19px;
  color: var(--ink-dim);
  margin: 0;
  max-width: 62ch;
}
.build-goal {
  margin-top: 26px;
  display: inline-flex; align-items: center; gap: 12px;
  font-family: var(--mono);
  font-size: 13.5px;
  padding: 10px 16px;
  background: var(--bg-panel);
  border: 1px solid var(--line);
  border-left: 3px solid var(--green);
  border-radius: 6px;
  color: var(--ink);
}
.build-goal b { color: var(--green); font-weight: 600; }

/* ---------- typography ---------- */
h2 {
  font-size: 27px;
  letter-spacing: -0.01em;
  margin: 52px 0 18px;
  padding-top: 10px;
  font-weight: 700;
}
h2 .num {
  font-family: var(--mono);
  font-size: 15px;
  color: var(--blue);
  margin-right: 12px;
  font-weight: 500;
}
.track-3d h2 .num { color: var(--violet); }
h3 {
  font-size: 20px;
  margin: 36px 0 12px;
  font-weight: 650;
  color: var(--ink);
}
p { margin: 0 0 18px; }
a { color: var(--blue-soft); }
strong { color: #eef2f7; font-weight: 650; }
em { color: var(--ink); }
ul, ol { margin: 0 0 20px; padding-left: 24px; }
li { margin: 7px 0; }
hr { border: 0; border-top: 1px solid var(--line); margin: 44px 0; }

/* inline code */
code {
  font-family: var(--mono);
  font-size: 0.9em;
  background: var(--bg-code);
  border: 1px solid var(--line);
  border-radius: 4px;
  padding: 1.5px 6px;
  color: var(--blue-soft);
}
kbd {
  font-family: var(--mono);
  font-size: 0.82em;
  background: var(--bg-panel);
  border: 1px solid var(--line);
  border-bottom-width: 2px;
  border-radius: 5px;
  padding: 2px 7px;
  color: var(--ink);
}

/* ---------- code blocks ---------- */
.code {
  position: relative;
  background: var(--bg-code);
  border: 1px solid var(--line);
  border-radius: var(--radius);
  margin: 22px 0;
  overflow: hidden;
}
.code-head {
  display: flex; align-items: center; gap: 8px;
  padding: 9px 14px;
  background: var(--bg-panel);
  border-bottom: 1px solid var(--line);
  font-family: var(--mono);
  font-size: 12px;
  color: var(--ink-faint);
}
.code-head .fname { color: var(--ink-dim); }
.code-head .lang {
  margin-left: auto;
  color: var(--blue);
  text-transform: lowercase;
  letter-spacing: .04em;
}
.code pre {
  margin: 0;
  padding: 16px 18px;
  overflow-x: auto;
  font-family: var(--mono);
  font-size: 13.5px;
  line-height: 1.62;
  color: var(--ink);
  tab-size: 4;
}
.code pre code {
  background: none; border: 0; padding: 0; color: inherit; font-size: inherit;
}

/* GDScript-ish token coloring via spans */
.tok-kw   { color: #f07178; }   /* keyword         */
.tok-fn   { color: #82aaff; }   /* func name       */
.tok-type { color: #6bd4c4; }   /* type / class    */
.tok-str  { color: #c3e88d; }   /* string          */
.tok-num  { color: #f78c6c; }   /* number          */
.tok-com  { color: #566072; font-style: italic; }  /* comment */
.tok-cst  { color: #e8b24a; }   /* constant        */
.tok-node { color: #a988e0; }   /* node path / $   */

/* ---------- callouts ---------- */
.note {
  border: 1px solid var(--line);
  border-left: 3px solid var(--blue);
  background: var(--bg-panel);
  border-radius: 6px;
  padding: 15px 18px;
  margin: 22px 0;
}
.note .lbl {
  font-family: var(--mono);
  font-size: 11.5px;
  letter-spacing: .12em;
  text-transform: uppercase;
  color: var(--blue);
  margin: 0 0 6px;
  font-weight: 600;
}
.note p:last-child { margin-bottom: 0; }

.note.warn  { border-left-color: var(--amber); }
.note.warn  .lbl { color: var(--amber); }
.note.gotcha { border-left-color: var(--red); }
.note.gotcha .lbl { color: var(--red); }
.note.win   { border-left-color: var(--green); }
.note.win   .lbl { color: var(--green); }

/* ---------- editor step (do-this-in-Godot) ---------- */
.steps {
  counter-reset: step;
  list-style: none;
  padding: 0;
  margin: 22px 0;
}
.steps > li {
  position: relative;
  counter-increment: step;
  padding: 4px 0 16px 44px;
  margin: 0;
  border-left: 1px solid var(--line);
  margin-left: 13px;
}
.steps > li:last-child { border-left-color: transparent; }
.steps > li::before {
  content: counter(step);
  position: absolute;
  left: -13px; top: 0;
  width: 26px; height: 26px;
  background: var(--bg-panel);
  border: 1px solid var(--blue);
  color: var(--blue);
  border-radius: 50%;
  display: grid; place-items: center;
  font-family: var(--mono);
  font-size: 12.5px;
  font-weight: 600;
}
.track-3d .steps > li::before { border-color: var(--violet); color: var(--violet); }

/* ---------- checkpoint ---------- */
.checkpoint {
  margin: 34px 0;
  padding: 20px 22px;
  background: linear-gradient(180deg, var(--bg-panel), var(--bg-code));
  border: 1px solid var(--line);
  border-radius: var(--radius);
}
.checkpoint .lbl {
  font-family: var(--mono);
  font-size: 12px;
  letter-spacing: .14em;
  text-transform: uppercase;
  color: var(--green);
  margin: 0 0 10px;
  display: flex; align-items: center; gap: 8px;
}
.checkpoint .lbl::before { content: "▶"; font-size: 10px; }
.checkpoint ul { margin-bottom: 0; }

/* ---------- footer nav ---------- */
.lesson-nav {
  margin-top: 64px;
  padding-top: 26px;
  border-top: 1px solid var(--line);
  display: flex; gap: 14px;
}
.lesson-nav a {
  flex: 1;
  text-decoration: none;
  padding: 16px 18px;
  border: 1px solid var(--line);
  border-radius: var(--radius);
  background: var(--bg-panel);
  transition: border-color .15s, transform .15s;
}
.lesson-nav a:hover { border-color: var(--blue); transform: translateY(-2px); }
.lesson-nav .dir { font-family: var(--mono); font-size: 11.5px; color: var(--ink-faint); letter-spacing: .1em; text-transform: uppercase; }
.lesson-nav .ttl { display: block; margin-top: 5px; color: var(--ink); font-weight: 600; }
.lesson-nav .next { text-align: right; }
.lesson-nav .disabled { opacity: .35; pointer-events: none; }

/* ================================================================
   INDEX / SYLLABUS PAGE
   ================================================================ */
.hero {
  padding: 88px 0 40px;
  text-align: left;
}
.hero .kicker {
  font-family: var(--mono);
  font-size: 13px;
  letter-spacing: .2em;
  text-transform: uppercase;
  color: var(--blue);
  margin: 0 0 20px;
}
.hero h1 { font-size: 58px; line-height: 1.04; margin-bottom: 20px; }
.hero .sub { font-size: 21px; color: var(--ink-dim); max-width: 60ch; margin: 0 0 30px; }
.hero .meta {
  display: flex; flex-wrap: wrap; gap: 10px; margin-top: 28px;
}
.chip {
  font-family: var(--mono);
  font-size: 12.5px;
  padding: 7px 13px;
  background: var(--bg-panel);
  border: 1px solid var(--line);
  border-radius: 20px;
  color: var(--ink-dim);
}
.chip b { color: var(--blue); font-weight: 600; }

.target-game {
  margin: 40px 0;
  padding: 24px 26px;
  border: 1px solid var(--line);
  border-left: 3px solid var(--amber);
  border-radius: var(--radius);
  background: var(--bg-panel);
}
.target-game h3 { margin-top: 0; color: var(--amber); font-family: var(--mono); font-size: 14px; letter-spacing: .1em; text-transform: uppercase; }
.target-game p:last-child { margin-bottom: 0; }

.module {
  margin: 30px 0;
  border: 1px solid var(--line);
  border-radius: var(--radius);
  overflow: hidden;
  background: var(--bg-panel);
}
.module-head {
  padding: 16px 22px;
  display: flex; align-items: baseline; gap: 14px;
  border-bottom: 1px solid var(--line);
}
.module-head .mnum { font-family: var(--mono); color: var(--blue); font-size: 14px; }
.track-3d-page .module-head .mnum { color: var(--violet); }
.module-head .mttl { font-size: 19px; font-weight: 700; }
.module-head .mcount { margin-left: auto; font-family: var(--mono); font-size: 12px; color: var(--ink-faint); }
.lessons { list-style: none; margin: 0; padding: 6px 0; }
.lessons li a {
  display: flex; align-items: center; gap: 14px;
  padding: 12px 22px;
  text-decoration: none;
  color: var(--ink);
  transition: background .12s;
}
.lessons li a:hover { background: var(--bg-code); }
.lessons .lz { font-family: var(--mono); font-size: 12.5px; color: var(--ink-faint); min-width: 34px; }
.lessons .lt { flex: 1; }
.lessons .lg { font-family: var(--mono); font-size: 11.5px; color: var(--green); opacity: .8; }

.section-title {
  font-family: var(--mono);
  font-size: 13px;
  letter-spacing: .16em;
  text-transform: uppercase;
  color: var(--ink-faint);
  margin: 56px 0 8px;
  padding-bottom: 10px;
  border-bottom: 1px solid var(--line);
}

/* ---------- responsive ---------- */
@media (max-width: 600px) {
  body { font-size: 16px; }
  h1 { font-size: 32px; }
  .hero h1 { font-size: 40px; }
  .hero { padding: 56px 0 30px; }
  h2 { font-size: 23px; }
  .lesson-nav { flex-direction: column; }
  .code pre { font-size: 12.5px; }
}

/* keyboard focus */
a:focus-visible, kbd:focus-visible {
  outline: 2px solid var(--blue);
  outline-offset: 2px;
  border-radius: 3px;
}

@media (prefers-reduced-motion: reduce) {
  * { scroll-behavior: auto !important; transition: none !important; }
}

/* ================================================================
   Interaction upgrades — copy, progress, nav hints
   ================================================================ */

/* Copy button on code blocks */
.code-head { position: relative; }
.copy-btn {
  margin-left: auto;
  font-family: var(--mono);
  font-size: 11.5px;
  letter-spacing: .04em;
  padding: 3px 10px;
  border-radius: 5px;
  border: 1px solid var(--line);
  background: var(--bg-code);
  color: var(--ink-dim);
  cursor: pointer;
  transition: color .15s, border-color .15s, background .15s;
}
.copy-btn:hover {
  color: var(--ink);
  border-color: var(--blue);
  background: rgba(74, 143, 231, 0.08);
}
.copy-btn.copied {
  color: var(--green);
  border-color: var(--green);
}
.copy-btn-float {
  position: absolute;
  top: 8px;
  right: 10px;
  z-index: 2;
}
.code { position: relative; }

/* Topbar lesson progress strip */
.topbar { position: sticky; top: 0; z-index: 50; }
.topbar-progress {
  height: 2px;
  background: transparent;
  width: 100%;
}
.topbar-progress-fill {
  height: 100%;
  background: linear-gradient(90deg, var(--blue), var(--blue-soft));
  transition: width .35s ease;
}
.track-3d .topbar-progress-fill,
html.track-3d .topbar-progress-fill {
  background: linear-gradient(90deg, var(--violet), #c4a8f0);
}

/* Syllabus completed lessons */
.lessons a.done .lt { color: var(--ink-dim); }
.lessons a.done .lz { color: var(--green); }
.lessons .done-mark {
  font-family: var(--mono);
  font-size: 12px;
  color: var(--green);
  margin-left: 6px;
  opacity: 0.9;
}

/* Progress summary on syllabus hero */
.progress-summary {
  margin-top: 28px;
  max-width: 320px;
}
.progress-label {
  display: flex;
  justify-content: space-between;
  font-family: var(--mono);
  font-size: 12.5px;
  color: var(--ink-dim);
  margin-bottom: 8px;
}
.progress-track {
  height: 6px;
  background: var(--bg-code);
  border: 1px solid var(--line);
  border-radius: 99px;
  overflow: hidden;
}
.progress-fill {
  height: 100%;
  background: linear-gradient(90deg, var(--blue), var(--green));
  border-radius: 99px;
  transition: width .4s ease;
}
.track-3d-page .progress-fill,
html.track-3d .progress-fill {
  background: linear-gradient(90deg, var(--violet), var(--green));
}

/* Keyboard nav hint */
.nav-hint {
  margin: 14px 0 0;
  font-family: var(--mono);
  font-size: 12px;
  color: var(--ink-faint);
  text-align: center;
  letter-spacing: .02em;
}

/* Copy sits after the lang label; lang keeps margin-left:auto */
.code-head .copy-btn {
  flex-shrink: 0;
}

/* Focus ring for accessibility */
.copy-btn:focus-visible,
.lesson-nav a:focus-visible,
.lessons a:focus-visible {
  outline: 2px solid var(--blue);
  outline-offset: 2px;
}

/* Soft selection color inside code */
.code pre ::selection {
  background: rgba(74, 143, 231, 0.28);
}

/* Empty note class cleanup helper — keep default note styling */
.note:not(.warn):not(.gotcha):not(.win) {
  border-left-color: var(--blue);
}

/* Last-viewed lesson on syllabus */
.lessons a.current {
  background: rgba(74, 143, 231, 0.08);
  border-left: 2px solid var(--blue);
  padding-left: 20px;
}
html.track-3d .lessons a.current,
.track-3d-page .lessons a.current {
  background: rgba(169, 136, 224, 0.1);
  border-left-color: var(--violet);
}
.lessons a.current .lt {
  color: var(--ink);
  font-weight: 600;
}