/* ==========================================================================
   DCC Youth theme — ages 13–17
   Design basis (see hal-stack/product-intelligence/dcc-youth-research-2026-07-12.md):
   - NN/g teen UX research: clean, professional, whitespace; teens reject
     childish aesthetics, garish colour, and pointless animation.
   - More energy than the senior "no pulse" register, but every motion is
     purposeful (progress, feedback, reveal) and zeroed under
     prefers-reduced-motion.
   - Phone-first: Pew 2025 — 95%+ of teens are smartphone-first.
   Loads AFTER ../css/tokens.css (fonts + base tokens + dark theme come from there).
   ========================================================================== */

:root {
  --yt-indigo:        #3949AB;
  --yt-indigo-deep:   #2C3A8C;
  --yt-indigo-bg:     #E8EAF6;
  --yt-teal:          #00796B; /* 4.65:1 on white — AA for large text/UI; body text uses --yt-text */
  --yt-teal-bg:       #E0F2F1;
  --yt-green:         #2E7D32;
  --yt-green-bg:      #E8F5E9;
  --yt-red:           #C62828;
  --yt-red-bg:        #FFEBEE;
  --yt-bg:            #FAFAFC;
  --yt-surface:       #FFFFFF;
  --yt-surface-alt:   #F1F2F8;
  --yt-text:          #1F2430;
  --yt-text-soft:     #4A5060; /* 7.4:1 on white */
  --yt-border:        #D9DCE8;
  --yt-hero-a:        #16203E;
  --yt-hero-b:        #3949AB;
  --yt-focus:         #A85410;
  --yt-radius:        14px;
  --yt-motion:        220ms;
}

html[data-theme="dark"] {
  --yt-indigo:        #9FA8DA;
  --yt-indigo-deep:   #7986CB;
  --yt-indigo-bg:     #262B47;
  --yt-teal:          #4DB6AC;
  --yt-teal-bg:       #1C3330;
  --yt-green:         #81C784;
  --yt-green-bg:      #1E3320;
  --yt-red:           #EF9A9A;
  --yt-red-bg:        #3A2022;
  --yt-bg:            #14161E;
  --yt-surface:       #1D2029;
  --yt-surface-alt:   #232734;
  --yt-text:          #E8EAF2;
  --yt-text-soft:     #B4B9C9;
  --yt-border:        #363B4C;
  --yt-hero-a:        #10182F;
  --yt-hero-b:        #2C3A8C;
  --yt-focus:         #F5A860;
}

@media (prefers-reduced-motion: reduce) {
  :root { --yt-motion: 0ms; }
  .yt-scenario.active { animation: none; }
}

/* ---------- base ---------- */
.yt-body {
  margin: 0;
  background: var(--yt-bg);
  color: var(--yt-text);
  font-family: 'Source Sans 3', 'Segoe UI', system-ui, sans-serif;
  font-size: 1.0625rem;
  line-height: 1.65;
  -webkit-text-size-adjust: 100%;
  /* Unbreakable-token safety (passwords.google.com class) — youth pages load
     only tokens.css + this file, so the 2026-08-10 core.css body fix never
     reaches them. Inert on normal text. (Brand-audit Phase 2, DCC Kids/Youth.) */
  overflow-wrap: break-word;
}
.yt-container { max-width: 680px; margin: 0 auto; padding: 0 1.1rem; }
.yt-body a { color: var(--yt-indigo); }
.yt-body :focus-visible { outline: 3px solid var(--yt-focus); outline-offset: 2px; border-radius: 4px; }
.yt-skip {
  position: absolute; left: -9999px; top: 0; z-index: 10;
  background: var(--yt-surface); color: var(--yt-text); padding: 0.6rem 1rem;
}
.yt-skip:focus { left: 0.5rem; top: 0.5rem; }

/* ---------- header ---------- */
.yt-header {
  display: flex; align-items: center; justify-content: space-between; gap: 0.75rem;
  padding: 0.8rem 1.1rem;
  max-width: 680px; margin: 0 auto;
}
.yt-brand {
  font-weight: 700; font-size: 0.95rem; text-decoration: none;
  color: var(--yt-text);
}
.yt-brand .yt-brand-tag { color: var(--yt-indigo); }
.yt-theme-btn {
  min-height: 44px; min-width: 44px;
  border: 1.5px solid var(--yt-border); border-radius: 10px;
  background: var(--yt-surface); color: var(--yt-text);
  font: inherit; font-size: 0.9rem; cursor: pointer; padding: 0.35rem 0.8rem;
}
.yt-theme-btn:hover { border-color: var(--yt-indigo); }

/* ---------- hero ---------- */
.yt-hero {
  background: linear-gradient(140deg, var(--yt-hero-a) 0%, var(--yt-hero-b) 100%);
  color: #fff;
  padding: 2.4rem 0 2.1rem;
  border-radius: 0 0 20px 20px;
}
.yt-hero .yt-eyebrow {
  display: inline-block;
  background: rgba(255,255,255,0.14);
  border: 1px solid rgba(255,255,255,0.35);
  border-radius: 999px;
  padding: 0.28rem 0.9rem;
  font-size: 0.8rem; font-weight: 700; letter-spacing: 0.06em; text-transform: uppercase;
  margin-bottom: 0.8rem;
}
.yt-hero h1 {
  font-size: clamp(1.7rem, 5.5vw, 2.5rem);
  font-weight: 800; line-height: 1.12; margin: 0 0 0.7rem;
}
.yt-hero p { font-size: 1.05rem; line-height: 1.55; margin: 0; max-width: 34em; color: rgba(255,255,255,0.92); }

/* ---------- straight-with-you strip (trust, teen register) ---------- */
.yt-straight {
  display: flex; flex-wrap: wrap; gap: 0.4rem 1.1rem;
  list-style: none; margin: 1.1rem 0 0; padding: 0;
  font-size: 0.92rem; color: var(--yt-text-soft);
}
.yt-straight li::before { content: "✓ "; color: var(--yt-teal); font-weight: 700; }

/* ---------- progress ---------- */
.yt-progress { display: flex; align-items: center; gap: 0.7rem; margin: 1.6rem 0 1.2rem; }
.yt-pip {
  width: 34px; height: 7px; border-radius: 4px;
  background: var(--yt-indigo-bg);
  transition: background var(--yt-motion) ease;
}
.yt-pip.done { background: var(--yt-indigo); }
.yt-pip.active { background: var(--yt-teal); }
.yt-progress-label { font-size: 0.85rem; font-weight: 600; color: var(--yt-text-soft); }

/* ---------- scenario cards ---------- */
.yt-scenario {
  background: var(--yt-surface);
  border: 1.5px solid var(--yt-border);
  border-radius: var(--yt-radius);
  overflow: hidden;
  margin-bottom: 1.6rem;
  display: none;
}
.yt-scenario.active { display: block; animation: yt-rise var(--yt-motion) ease-out; }
@keyframes yt-rise {
  from { opacity: 0; transform: translateY(10px); }
  to   { opacity: 1; transform: none; }
}
.yt-scenario-head {
  display: flex; align-items: center; gap: 0.7rem;
  background: var(--yt-surface-alt);
  padding: 0.85rem 1.2rem;
  border-bottom: 1.5px solid var(--yt-border);
}
.yt-scenario-num {
  background: var(--yt-indigo); color: var(--yt-surface);
  width: 2rem; height: 2rem; border-radius: 50%;
  display: flex; align-items: center; justify-content: center;
  font-size: 0.9rem; font-weight: 800; flex-shrink: 0;
}
html[data-theme="dark"] .yt-scenario-num { color: #14161E; }
.yt-scenario-tag {
  font-size: 0.78rem; font-weight: 700; letter-spacing: 0.05em;
  text-transform: uppercase; color: var(--yt-indigo);
}
.yt-scenario-body { padding: 1.2rem; }
.yt-scenario-title { font-size: 1.15rem; font-weight: 800; margin: 0 0 0.7rem; }
.yt-story {
  background: var(--yt-surface-alt);
  border-left: 4px solid var(--yt-indigo);
  border-radius: 0 10px 10px 0;
  padding: 0.9rem 1.1rem;
  margin: 0 0 1.1rem;
}
.yt-question { font-weight: 700; margin: 0 0 0.7rem; }

/* answers */
.yt-answers { display: flex; flex-direction: column; gap: 0.5rem; margin-bottom: 1rem; }
.yt-answer {
  display: flex; align-items: flex-start; gap: 0.7rem;
  min-height: 44px;
  padding: 0.7rem 0.9rem;
  border: 2px solid var(--yt-border);
  border-radius: 10px;
  background: var(--yt-surface);
  color: var(--yt-text);
  font: inherit; text-align: left; cursor: pointer; width: 100%;
  transition: border-color var(--yt-motion) ease, background var(--yt-motion) ease;
}
.yt-answer:hover:not(:disabled) { border-color: var(--yt-indigo); background: var(--yt-indigo-bg); }
.yt-answer .yt-letter {
  flex-shrink: 0; width: 1.55rem; height: 1.55rem; margin-top: 2px;
  background: var(--yt-indigo-bg); color: var(--yt-indigo);
  border-radius: 50%;
  display: flex; align-items: center; justify-content: center;
  font-size: 0.78rem; font-weight: 800;
}
.yt-answer:disabled { cursor: default; }
.yt-answer.is-correct { border-color: var(--yt-green); background: var(--yt-green-bg); }
.yt-answer.is-correct .yt-letter { background: var(--yt-green); color: #fff; }
html[data-theme="dark"] .yt-answer.is-correct .yt-letter { color: #14161E; }
.yt-answer.is-wrong { border-color: var(--yt-red); background: var(--yt-red-bg); }
.yt-answer.is-wrong .yt-letter { background: var(--yt-red); color: #fff; }
html[data-theme="dark"] .yt-answer.is-wrong .yt-letter { color: #14161E; }
.yt-answer.show-correct { border-color: var(--yt-green); background: var(--yt-green-bg); opacity: 0.75; }

/* debrief */
.yt-debrief {
  display: none;
  border-left: 4px solid var(--yt-teal);
  border-radius: 0 10px 10px 0;
  background: var(--yt-teal-bg);
  padding: 0.9rem 1.1rem;
  margin-top: 0.9rem;
}
.yt-debrief.visible { display: block; animation: yt-rise var(--yt-motion) ease-out; }
.yt-debrief-label {
  font-size: 0.76rem; font-weight: 800; letter-spacing: 0.06em; text-transform: uppercase;
  color: var(--yt-teal); margin: 0 0 0.35rem;
}
.yt-debrief p { margin: 0; }
.yt-debrief p + p { margin-top: 0.6rem; }

.yt-next {
  display: none;
  margin-top: 1rem;
  min-height: 48px;
  background: var(--yt-indigo); color: #fff;
  border: none; border-radius: 999px;
  padding: 0.65rem 1.7rem;
  font: inherit; font-weight: 700; cursor: pointer;
  transition: background var(--yt-motion) ease;
}
html[data-theme="dark"] .yt-next { color: #14161E; }
.yt-next:hover { background: var(--yt-indigo-deep); }
.yt-next.visible { display: inline-flex; align-items: center; gap: 0.4rem; }

/* results */
.yt-results {
  display: none;
  text-align: center;
  background: var(--yt-indigo-bg);
  border-radius: var(--yt-radius);
  padding: 1.8rem 1.1rem;
  margin-bottom: 1.6rem;
}
.yt-results.visible { display: block; animation: yt-rise var(--yt-motion) ease-out; }
.yt-results .yt-score { font-size: 1.5rem; font-weight: 800; color: var(--yt-indigo); }
.yt-results .yt-score-sub { margin: 0.4rem 0 0; color: var(--yt-text-soft); }

/* ---------- support / help block ---------- */
.yt-help {
  background: var(--yt-surface);
  border: 2px solid var(--yt-teal);
  border-radius: var(--yt-radius);
  padding: 1.1rem 1.2rem;
  margin: 1.6rem 0;
}
.yt-help h2, .yt-help h3 { margin: 0 0 0.5rem; font-size: 1.05rem; }
.yt-help ul { margin: 0.5rem 0 0; padding-left: 1.2rem; }
.yt-help li { margin-bottom: 0.4rem; }

/* ---------- takeaway ---------- */
.yt-takeaway {
  background: var(--yt-surface-alt);
  border-radius: var(--yt-radius);
  padding: 1.1rem 1.2rem;
  margin: 1.6rem 0;
}
.yt-takeaway h2 { font-size: 1.05rem; margin: 0 0 0.5rem; }
.yt-takeaway ul { margin: 0; padding-left: 1.2rem; }
.yt-takeaway li { margin-bottom: 0.35rem; }

/* ---------- hub cards ---------- */
.yt-grid { display: grid; grid-template-columns: 1fr; gap: 0.9rem; list-style: none; margin: 1.4rem 0; padding: 0; }
@media (min-width: 560px) { .yt-grid { grid-template-columns: 1fr 1fr; } }
.yt-card {
  background: var(--yt-surface);
  border: 1.5px solid var(--yt-border);
  border-radius: var(--yt-radius);
  padding: 1.1rem 1.2rem;
  transition: border-color var(--yt-motion) ease, transform var(--yt-motion) ease;
}
.yt-card:hover { border-color: var(--yt-indigo); transform: translateY(-2px); }
@media (prefers-reduced-motion: reduce) { .yt-card:hover { transform: none; } }
.yt-card .yt-card-tag {
  font-size: 0.76rem; font-weight: 800; letter-spacing: 0.06em; text-transform: uppercase;
  color: var(--yt-teal);
}
.yt-card h2, .yt-card h3 { font-size: 1.12rem; margin: 0.3rem 0 0.4rem; line-height: 1.3; }
.yt-card h2 a, .yt-card h3 a { color: var(--yt-text); text-decoration: none; }
.yt-card h2 a::after, .yt-card h3 a::after { content: ""; position: absolute; inset: 0; }
.yt-card { position: relative; }
.yt-card p { margin: 0; font-size: 0.95rem; color: var(--yt-text-soft); }
.yt-card .yt-mins { display: inline-block; margin-top: 0.6rem; font-size: 0.85rem; font-weight: 600; color: var(--yt-indigo); }

/* ---------- related / footer nav ---------- */
.yt-related { margin: 2rem 0 1rem; }
.yt-related h2 { font-size: 1.1rem; }
.yt-footnav {
  display: flex; justify-content: space-between; gap: 1rem;
  margin: 2rem 0 1rem; font-weight: 600;
}
.yt-footer {
  border-top: 1.5px solid var(--yt-border);
  margin-top: 2.5rem;
  padding: 1.4rem 0 2rem;
  font-size: 0.88rem; color: var(--yt-text-soft);
}
.yt-footer nav { display: flex; flex-wrap: wrap; gap: 0.4rem 1rem; margin-bottom: 0.6rem; }
.yt-footer a { color: var(--yt-text-soft); }
.yt-footer p { margin: 0.25rem 0 0; }

.yt-section-h { font-size: 1.35rem; margin: 2rem 0 0.4rem; }
.yt-lead { color: var(--yt-text-soft); margin-top: 0; }

/* ==========================================================================
   Course pages (certificate tracks) — added 2026-07-16
   Reuses the module vocabulary (help block, story, takeaway, answers);
   adds lesson sections, a 25-question check, and a printable certificate.
   ========================================================================== */

.yt-lesson { margin: 2rem 0; }
.yt-lesson h2 { font-size: 1.3rem; margin: 0 0 0.6rem; }
.yt-lesson h3 { font-size: 1.05rem; margin: 1.1rem 0 0.4rem; }
.yt-lesson p { margin: 0 0 0.8rem; }
.yt-lesson ul { margin: 0 0 0.8rem; padding-left: 1.2rem; }
.yt-lesson li { margin-bottom: 0.35rem; }
.yt-src {
  font-size: 0.85rem; color: var(--yt-text-soft);
  border-left: 3px solid var(--yt-border);
  padding-left: 0.7rem; margin: 0.6rem 0 0;
}
.yt-btn {
  display: inline-flex; align-items: center; gap: 0.4rem;
  min-height: 48px;
  background: var(--yt-indigo); color: #fff;
  border: none; border-radius: 999px;
  padding: 0.65rem 1.7rem;
  font: inherit; font-weight: 700; cursor: pointer;
  transition: background var(--yt-motion) ease;
}
html[data-theme="dark"] .yt-btn { color: #14161E; }
.yt-btn:hover { background: var(--yt-indigo-deep); }
.yt-btn-quiet {
  background: var(--yt-surface); color: var(--yt-text);
  border: 2px solid var(--yt-border);
}
html[data-theme="dark"] .yt-btn-quiet { color: var(--yt-text); }
.yt-btn-quiet:hover { background: var(--yt-surface-alt); border-color: var(--yt-indigo); }

/* quiz shell */
.yt-quiz {
  background: var(--yt-surface);
  border: 1.5px solid var(--yt-border);
  border-radius: var(--yt-radius);
  padding: 1.2rem;
  margin: 1.6rem 0;
}
.yt-quiz .yt-quiz-q { font-weight: 700; margin: 0 0 0.7rem; font-size: 1.05rem; }
.yt-quiz .yt-progress { margin: 0 0 1rem; }

/* certificate */
.yt-cert-form { margin: 1.2rem 0 0; }
.yt-cert-form label { display: block; font-weight: 700; margin-bottom: 0.3rem; }
.yt-cert-form input {
  width: 100%; max-width: 24em; box-sizing: border-box;
  min-height: 48px;
  border: 2px solid var(--yt-border); border-radius: 10px;
  background: var(--yt-surface); color: var(--yt-text);
  font: inherit; padding: 0.5rem 0.8rem; margin-bottom: 0.8rem;
}
.yt-cert {
  display: none;
  background: var(--yt-surface);
  border: 3px double var(--yt-indigo);
  border-radius: var(--yt-radius);
  padding: 2rem 1.4rem;
  margin: 1.6rem 0;
  text-align: center;
}
.yt-cert.visible { display: block; animation: yt-rise var(--yt-motion) ease-out; }
.yt-cert .yt-cert-brand {
  font-size: 0.78rem; font-weight: 800; letter-spacing: 0.08em; text-transform: uppercase;
  color: var(--yt-teal); margin: 0 0 0.8rem;
}
.yt-cert h2 { font-size: 1.05rem; font-weight: 600; margin: 0 0 0.3rem; color: var(--yt-text-soft); }
.yt-cert .yt-cert-name { font-size: 1.7rem; font-weight: 800; margin: 0.2rem 0 0.6rem; }
.yt-cert .yt-cert-course { font-size: 1.15rem; font-weight: 700; margin: 0 0 0.8rem; }
.yt-cert .yt-cert-meta { font-size: 0.92rem; color: var(--yt-text-soft); margin: 0; }
.yt-cert .yt-cert-meta + .yt-cert-meta { margin-top: 0.25rem; }

@media print {
  body.yt-printing { background: #fff; }
  body.yt-printing * { visibility: hidden; }
  body.yt-printing .yt-cert, body.yt-printing .yt-cert * { visibility: visible; }
  body.yt-printing .yt-cert {
    display: block !important;
    position: absolute; left: 0; top: 0; width: 100%; box-sizing: border-box;
    border-color: #000; background: #fff;
    margin: 0; max-width: none;
  }
  body.yt-printing .yt-cert * { color: #000 !important; }
  body.yt-printing .yt-cert .yt-btn { display: none !important; }
}