/* NextGen Coders Lab — Galaxy Defender course
   Palette pulled from the infographics:
   space-blue #1f3b5b, red #ef5350, orange #f5a623,
   green #4caf6e, purple #8e5fb3, yellow #f7d24a */

:root {
  --space:      #0e1a2e;
  --space-2:    #1f3b5b;
  --paper:      #f3f6fb;
  --ink:        #16243a;
  --muted:      #6b7c93;
  --red:        #ef5350;
  --orange:     #f5a623;
  --green:      #4caf6e;
  --purple:     #8e5fb3;
  --yellow:     #f7d24a;
  --radius:     14px;
  --shadow:     0 6px 24px rgba(14,26,46,.08);
  --shadow-lg:  0 18px 48px rgba(14,26,46,.18);
}

* { box-sizing: border-box; }
html, body { margin: 0; padding: 0; }
body {
  font-family: 'Nunito', system-ui, -apple-system, Segoe UI, Roboto, sans-serif;
  color: var(--ink);
  background: var(--paper);
  line-height: 1.55;
}

a { color: var(--space-2); text-decoration: none; }
a:hover { text-decoration: underline; }

/* ── Header ────────────────────────────── */
.site-header {
  background: var(--space);
  color: #fff;
  padding: 14px 24px;
  display: flex;
  align-items: center;
  justify-content: space-between;
  position: sticky;
  top: 0;
  z-index: 50;
  box-shadow: var(--shadow);
}
.site-header .brand {
  font-weight: 800;
  letter-spacing: .5px;
  font-size: 1.05rem;
}
.site-header .brand .dot { color: var(--yellow); }
.site-header nav a,
.site-header nav .lesson-menu > summary {
  color: #cfe2ff;
  margin-left: 18px;
  font-weight: 600;
  font-size: .95rem;
}
.site-header nav a:hover { color: #fff; text-decoration: none; }

/* ── Lesson dropdown in the header ────────────────── */
.lesson-menu {
  position: relative;
  display: inline-block;
}
.lesson-menu > summary {
  cursor: pointer;
  list-style: none;
  user-select: none;
  display: inline-block;
}
.lesson-menu > summary::-webkit-details-marker { display: none; }
.lesson-menu > summary::after { content: " ▾"; }
.lesson-menu[open] > summary { color: #fff; }

.lesson-menu ul {
  position: absolute;
  top: calc(100% + 10px);
  right: 0;
  background: #fff;
  border-radius: 12px;
  box-shadow: 0 12px 32px rgba(0, 0, 0, .28);
  list-style: none;
  margin: 0;
  padding: 8px;
  min-width: 250px;
  z-index: 200;
}
.lesson-menu li { margin: 0; }
.lesson-menu li a {
  display: flex;
  align-items: center;
  gap: 8px;
  padding: 9px 12px;
  border-radius: 8px;
  color: var(--ink);
  font-weight: 600;
  font-size: .9rem;
  margin: 0;                    /* override the .site-header nav a margin */
  text-decoration: none;
}
.lesson-menu li a:hover { background: var(--paper); color: var(--space); }
.lesson-menu li a.current {
  background: var(--space-2);
  color: #fff;
}
.lesson-menu li a .num-prefix {
  display: inline-block;
  width: 22px;
  text-align: right;
  color: var(--muted);
  font-weight: 800;
}
.lesson-menu li a.current .num-prefix { color: var(--yellow); }
.lesson-menu li a .label { flex: 1; }
.lesson-menu li a .tick,
.lesson-menu li a .free-tag,
.lesson-menu li a .lock {
  display: inline-block;
  font-size: .7rem;
  font-weight: 800;
  padding: 2px 6px;
  border-radius: 4px;
  margin-left: 4px;
}
.lesson-menu li a .tick {
  background: var(--green);
  color: #fff;
}
.lesson-menu li a .free-tag {
  background: var(--yellow);
  color: var(--space);
}
.lesson-menu li a .lock {
  background: transparent;
  font-size: .85rem;
  padding: 0;
  color: var(--muted);
}

/* ── Roadmap tick when a lesson is done ───────────── */
.roadmap a.done {
  background: linear-gradient(135deg, #4caf6e 0%, #3d9659 100%);
  color: #fff;
  border-top-color: var(--yellow);
}
.roadmap a.done .num { color: #fff; }
.roadmap a.done .tick {
  display: block;
  margin-top: 4px;
  color: var(--yellow);
  font-weight: 800;
  font-size: 1.1rem;
}

/* ── Hero ──────────────────────────────── */
.hero {
  background: radial-gradient(ellipse at top, #1f3b5b 0%, #0e1a2e 70%);
  color: #fff;
  padding: 64px 24px 80px;
  text-align: center;
}
.hero h1 {
  font-size: clamp(2rem, 4.5vw, 3.4rem);
  margin: 0 0 12px;
  letter-spacing: -.5px;
}
.hero p.lead {
  font-size: 1.15rem;
  color: #cfe2ff;
  max-width: 680px;
  margin: 0 auto 28px;
}
.hero .cta {
  display: inline-block;
  background: var(--yellow);
  color: #16243a;
  font-weight: 800;
  padding: 14px 26px;
  border-radius: 999px;
  box-shadow: var(--shadow-lg);
  transition: transform .15s;
}
.hero .cta:hover { transform: translateY(-2px); text-decoration: none; }
.hero .cta.secondary {
  background: transparent;
  color: #fff;
  border: 2px solid #cfe2ff;
  margin-left: 8px;
}

/* ── Containers ────────────────────────── */
.wrap { max-width: 980px; margin: 0 auto; padding: 32px 24px; }
.wrap.narrow { max-width: 760px; }

.card {
  background: #fff;
  border-radius: var(--radius);
  box-shadow: var(--shadow);
  padding: 24px;
  margin-bottom: 20px;
}

/* ── Stage chip + meta ─────────────────── */
.stage-chip {
  display: inline-block;
  background: var(--space-2);
  color: #fff;
  font-weight: 800;
  padding: 6px 14px;
  border-radius: 999px;
  font-size: .85rem;
  letter-spacing: .5px;
}
.stage-chip.import   { background: var(--red); }
.stage-chip.setup    { background: var(--orange); color: #16243a;}
.stage-chip.body     { background: var(--green); }
.stage-chip.end      { background: var(--purple); }

h2.stage-title {
  font-size: 2rem;
  margin: 8px 0 6px;
}
.stage-sub {
  color: var(--muted);
  margin: 0 0 18px;
}

/* ── Infographic ───────────────────────── */
.infographic {
  display: block;
  width: 100%;
  max-width: 720px;
  margin: 18px auto;
  border-radius: var(--radius);
  box-shadow: var(--shadow);
  background: #fff;
}
.infographic.small { max-width: 460px; }
.caption {
  text-align: center;
  color: var(--muted);
  font-size: .9rem;
  margin: -6px 0 24px;
}

/* ── Rocket Ladder stage marker ─────────────────────
   Overlays a pulsing yellow arrow on each side of the
   Rocket Ladder image, pointing at the current stage.   */
.rocket-marker {
  position: relative;
  display: block;
  width: 100%;
  max-width: 720px;
  margin: 18px auto;
}
.rocket-marker img {
  display: block;
  width: 100%;
  border-radius: var(--radius);
  box-shadow: var(--shadow);
  background: #fff;
}
.rocket-marker .marker {
  position: absolute;
  font-size: 2.2rem;
  font-weight: 900;
  line-height: 1;
  color: var(--yellow);
  text-shadow:
    0 0 6px rgba(0, 0, 0, .55),
    0 0 14px rgba(247, 210, 74, .65);
  pointer-events: none;
  transform: translateY(-50%);
  animation: rocket-marker-pulse 1.4s ease-in-out infinite;
}
.rocket-marker .marker.left  { left: -6px; }
.rocket-marker .marker.right { right: -6px; }

@keyframes rocket-marker-pulse {
  0%, 100% { transform: translateY(-50%) scale(1);    opacity: .85; }
  50%      { transform: translateY(-50%) scale(1.25); opacity: 1;   }
}

/* Per-stage vertical position. Measured precisely against the
   regenerated 3_Rocket_Ladder.png (620×1020 canvas, body Y range
   195→825 px, ten 63 px rows). Step = 6.18% between stages. */
.rocket-marker.stage-1  .marker { top: 22.21%; }
.rocket-marker.stage-2  .marker { top: 28.38%; }
.rocket-marker.stage-3  .marker { top: 34.56%; }
.rocket-marker.stage-4  .marker { top: 40.74%; }
.rocket-marker.stage-5  .marker { top: 46.91%; }
.rocket-marker.stage-6  .marker { top: 53.09%; }
.rocket-marker.stage-7  .marker { top: 59.26%; }
.rocket-marker.stage-8  .marker { top: 65.44%; }
.rocket-marker.stage-9  .marker { top: 71.62%; }
.rocket-marker.stage-10 .marker { top: 77.79%; }

/* ── Recipe steps ──────────────────────── */
.recipe { counter-reset: step; padding: 0; list-style: none; }
.recipe li {
  position: relative;
  padding: 14px 16px 14px 60px;
  background: #fff;
  border-left: 6px solid var(--green);
  border-radius: 10px;
  margin-bottom: 10px;
  box-shadow: var(--shadow);
}
.recipe li::before {
  counter-increment: step;
  content: counter(step);
  position: absolute;
  left: 14px; top: 50%;
  transform: translateY(-50%);
  width: 32px; height: 32px;
  background: var(--green);
  color: #fff;
  border-radius: 50%;
  display: flex; align-items: center; justify-content: center;
  font-weight: 800;
}

/* ── Code blocks ───────────────────────── */
pre, code {
  font-family: 'Fira Code', 'Cascadia Code', Menlo, Consolas, monospace;
}
pre {
  background: #0e1a2e;
  color: #cfe2ff;
  padding: 18px;
  border-radius: 10px;
  overflow-x: auto;
  font-size: .95rem;
}
code.inline {
  background: #eef2f9;
  color: #16243a;
  padding: 2px 6px;
  border-radius: 4px;
}

/* ── Trinket embed ─────────────────────── */
.trinket-box {
  background: #fff;
  border: 2px dashed var(--space-2);
  border-radius: var(--radius);
  padding: 20px;
  margin: 24px 0;
  text-align: center;
}
.trinket-box .label {
  display: inline-block;
  background: var(--space-2);
  color: #fff;
  font-weight: 700;
  padding: 4px 12px;
  border-radius: 999px;
  font-size: .8rem;
  letter-spacing: .5px;
  margin-bottom: 12px;
}
.trinket-box iframe {
  width: 100%;
  height: 480px;
  border: 0;
  border-radius: 8px;
}
.trinket-box .placeholder-note {
  color: var(--muted);
  font-size: .9rem;
  margin-top: 8px;
}

/* ── Challenge ─────────────────────────── */
.challenge {
  background: linear-gradient(135deg, #fff7d6, #ffeaa0);
  border-radius: var(--radius);
  padding: 20px 24px;
  margin: 24px 0;
  border-left: 6px solid var(--yellow);
}
.challenge h3 { margin-top: 0; color: #8a6a00; }

/* ── Nav (next/prev) ───────────────────── */
.lesson-nav {
  display: flex;
  justify-content: space-between;
  gap: 12px;
  margin-top: 36px;
}
.lesson-nav a {
  flex: 1;
  background: #fff;
  padding: 16px 18px;
  border-radius: var(--radius);
  box-shadow: var(--shadow);
  font-weight: 700;
  color: var(--ink);
}
.lesson-nav a:hover { background: var(--paper); text-decoration: none; }
.lesson-nav .next { text-align: right; }
.lesson-nav .label {
  display: block;
  font-size: .75rem;
  text-transform: uppercase;
  color: var(--muted);
  letter-spacing: 1px;
}

/* ── Footer ────────────────────────────── */
.site-footer {
  background: var(--space);
  color: #cfe2ff;
  text-align: center;
  padding: 28px 24px;
  margin-top: 60px;
  font-size: .9rem;
}

/* ── Unlock page ──────────────────────── */
.unlock-wrap {
  min-height: 100vh;
  display: flex;
  align-items: center;
  justify-content: center;
  background: radial-gradient(ellipse at top, #1f3b5b 0%, #0e1a2e 70%);
  padding: 24px;
}
.unlock-card {
  background: #fff;
  border-radius: var(--radius);
  box-shadow: var(--shadow-lg);
  padding: 36px 32px;
  width: 100%;
  max-width: 420px;
  text-align: center;
}
.unlock-card h1 { margin-top: 0; }
.unlock-card input {
  width: 100%;
  padding: 12px 14px;
  border: 2px solid #e1e8f2;
  border-radius: 10px;
  font-size: 1rem;
  margin: 12px 0;
}
.unlock-card input:focus { border-color: var(--space-2); outline: none; }
.unlock-card button {
  width: 100%;
  background: var(--space-2);
  color: #fff;
  border: 0;
  padding: 14px;
  border-radius: 10px;
  font-weight: 800;
  font-size: 1rem;
  cursor: pointer;
}
.unlock-card button:hover { background: var(--space); }
.unlock-card .error {
  color: var(--red);
  font-weight: 700;
  margin-top: 10px;
  min-height: 1.4em;
}

/* ── Roadmap (Lesson 0) ───────────────── */
.roadmap {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(160px, 1fr));
  gap: 12px;
  margin: 24px 0;
}
.roadmap a {
  background: #fff;
  padding: 14px;
  border-radius: 10px;
  box-shadow: var(--shadow);
  text-align: center;
  font-weight: 700;
  color: var(--ink);
  border-top: 5px solid var(--green);
}
.roadmap a:hover { transform: translateY(-2px); text-decoration: none; }
.roadmap a .num {
  display: block;
  font-size: 1.6rem;
  color: var(--space-2);
}
.roadmap a.locked { opacity: .55; cursor: not-allowed; }
.roadmap a.capstone {
  grid-column: 1 / -1;
  background: linear-gradient(135deg, #fff7d6, #ffeaa0);
  border-top: 5px solid var(--yellow);
  font-size: 1rem;
  padding: 18px;
}
.roadmap a.capstone .num {
  display: inline-block;
  background: var(--yellow);
  color: var(--space);
  padding: 4px 10px;
  border-radius: 999px;
  font-size: 1.2rem;
  margin-right: 8px;
}
.roadmap a.capstone:hover { background: linear-gradient(135deg, #fff2c0, #ffd970); }

/* ── Quick Recap (spaced-review quizzes) ─── */
.quick-recap {
  background: linear-gradient(135deg, #eef6ff, #e1ecff);
  border-left: 6px solid var(--space-2);
  border-radius: var(--radius);
  padding: 18px 22px;
  margin: 20px 0;
  box-shadow: var(--shadow);
}
.quick-recap h3 {
  margin: 0 0 6px;
  color: var(--space-2);
  font-size: 1.1rem;
}
.quick-recap > p { margin: 0 0 12px; color: var(--muted); font-size: .9rem; }
.quick-recap details {
  background: #fff;
  border-radius: 8px;
  padding: 10px 14px;
  margin: 6px 0;
  border-left: 3px solid var(--green);
}
.quick-recap details[open] { border-left-color: var(--yellow); }
.quick-recap summary {
  cursor: pointer;
  font-weight: 700;
  color: var(--ink);
  list-style: none;
  display: flex;
  align-items: center;
  gap: 8px;
}
.quick-recap summary::-webkit-details-marker { display: none; }
.quick-recap summary::before {
  content: "▶";
  display: inline-block;
  font-size: .8rem;
  color: var(--space-2);
  transition: transform .15s;
}
.quick-recap details[open] summary::before { transform: rotate(90deg); }
.quick-recap details > p,
.quick-recap details > div {
  margin: 8px 0 2px 16px;
  color: var(--ink);
  font-size: .95rem;
  line-height: 1.5;
}

/* ── Collapsible long code blocks (Lesson 11) ── */
details.collapsible-code {
  background: #fff;
  border-radius: var(--radius);
  border: 1px solid #e1e8f2;
  margin: 16px 0;
  overflow: hidden;
  box-shadow: var(--shadow);
}
details.collapsible-code > summary {
  cursor: pointer;
  list-style: none;
  padding: 14px 18px;
  background: var(--space-2);
  color: #fff;
  font-weight: 700;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 10px;
}
details.collapsible-code > summary::-webkit-details-marker { display: none; }
details.collapsible-code > summary::after {
  content: "⌄ Click to show full code";
  font-size: .85rem;
  font-weight: 600;
  color: var(--yellow);
  background: rgba(255,255,255,.12);
  padding: 4px 10px;
  border-radius: 999px;
  white-space: nowrap;
}
details.collapsible-code[open] > summary::after {
  content: "⌃ Click to hide";
}
details.collapsible-code .preview {
  padding: 14px 18px;
  font-family: 'Fira Code', 'Cascadia Code', Menlo, Consolas, monospace;
  font-size: .85rem;
  background: #f7faff;
  color: var(--muted);
  border-top: 1px solid #e1e8f2;
  line-height: 1.5;
  white-space: pre;
  overflow-x: auto;
}
details.collapsible-code pre {
  margin: 0;
  border-radius: 0;
}

/* ── Utility ───────────────────────────── */
.center { text-align: center; }
.small { font-size: .9rem; color: var(--muted); }
.dl-btn {
  display: inline-block;
  background: var(--green);
  color: #fff;
  font-weight: 700;
  padding: 10px 18px;
  border-radius: 999px;
  margin-top: 8px;
}
.dl-btn:hover { background: #3d9659; text-decoration: none; }

/* ── Print stylesheet ──────────────────────────────
   Teachers / parents print lesson pages as handouts.
   Hides nav, footer, embeds, buttons — keeps the
   lesson body, headings, code, and infographics.    */
@media print {
  body { background: #fff; color: #000; font-size: 11pt; }
  .site-header,
  .site-footer,
  .lesson-nav,
  .trinket-box,
  .lesson-menu,
  .quick-recap details summary::before,
  details.collapsible-code > summary::after,
  iframe,
  video,
  .cta,
  .dl-btn,
  .lesson-menu ul {
    display: none !important;
  }
  /* Open every details block so all content prints */
  details:not(.collapsible-code) > summary { font-weight: 700; cursor: default; }
  details[open] > * { display: revert; }
  details:not([open]) > *:not(summary) { display: revert !important; }
  .wrap { max-width: 100%; padding: 0; }
  .card,
  .quick-recap,
  .challenge {
    box-shadow: none !important;
    border: 1px solid #ccc;
    page-break-inside: avoid;
    background: #fff !important;
  }
  pre, code { background: #f4f4f4 !important; color: #000 !important; }
  .infographic, .rocket-marker img { max-width: 90%; page-break-inside: avoid; }
  a { color: #000 !important; text-decoration: none !important; }
  /* Print one-line page header on every printed page */
  @page { margin: 16mm 14mm 18mm 14mm; }
  body::after {
    content: "NextGen Coders Lab · Galaxy Defender · printable handout · nextgencoders@jestechsolutions.co.uk";
    position: fixed;
    bottom: 6mm;
    left: 0;
    right: 0;
    text-align: center;
    font-size: 8pt;
    color: #888;
  }
}