/* =============================================================
   Advaslearning Hub — ai/ai_styles.css
   AI & Machine Learning course styles — loaded by the AI level
   layouts (app/ai/level-<N>/layout.tsx) AFTER the shared root
   /styles.css, so base tokens (--bg, --surface, --ink, --border,
   --brand, --game-*, --challenge-*, --font-mono, --radius*,
   --shadow) are already available.

   This file is self-contained for lessons: it carries the same
   .lesson-* structural rules used across the Hub (the AI layouts
   do NOT load python_styles.css) plus AI-only pieces:
     • per-level accent tokens (.ai-level--1 … --4)
     • <PromptCard> chat blocks + weak / compare variants
     • .ai-diagram concept figures
   ============================================================= */

/* ---------- 0. Per-level accent tokens ----------
   AI palette (see AI_Memory.md §7): L1 cyan · L2 violet · L3 amber
   · L4 emerald. We define our own level classes rather than reuse
   styles.css's .level--N (those carry Python's colours). */
.ai-level--1 { --accent: #06B6D4; --accent-dark: #0E7490; --accent-soft: #ECFEFF; }
.ai-level--2 { --accent: #8B5CF6; --accent-dark: #6D28D9; --accent-soft: #F5F3FF; }
.ai-level--3 { --accent: #F59E0B; --accent-dark: #B45309; --accent-soft: #FFFBEB; }
.ai-level--4 { --accent: #10B981; --accent-dark: #047857; --accent-soft: #ECFDF5; }

/* ---------- 1. Lesson page ---------- */
.lesson-page { background: var(--bg); }

.lesson-hero {
  position: relative;
  overflow: hidden;
  border-bottom: 1px solid var(--border);
  background:
    radial-gradient(900px 320px at 80% -120px,
      color-mix(in srgb, var(--accent, var(--brand)) 22%, transparent), transparent 60%),
    radial-gradient(800px 320px at 0% 110%,
      color-mix(in srgb, var(--accent, var(--brand)) 14%, transparent), transparent 60%),
    linear-gradient(180deg, #FFFFFF 0%, var(--accent-soft, var(--brand-soft)) 100%);
}
.lesson-hero__inner { max-width: 880px; margin: 0 auto; padding: 56px 24px 44px; }
.lesson-hero__crumbs {
  display: flex; flex-wrap: wrap; gap: 8px;
  font-family: var(--font-mono); font-size: 0.78rem;
  letter-spacing: 0.08em; text-transform: uppercase;
  color: var(--accent-dark, var(--brand-deep)); margin: 0 0 14px;
}
.lesson-hero__crumbs a { color: var(--accent-dark, var(--brand-deep)); text-decoration: none; }
.lesson-hero__crumbs a:hover { text-decoration: underline; }
.lesson-hero__crumbs .sep  { color: var(--muted); }
.lesson-hero__crumbs .here { color: var(--muted); font-weight: 600; }

.lesson-hero__num {
  display: inline-block; font-family: var(--font-mono);
  font-size: 0.78rem; font-weight: 700; letter-spacing: 0.1em;
  text-transform: uppercase; background: var(--accent, var(--brand));
  color: #fff; padding: 6px 14px; border-radius: 999px; margin-bottom: 16px;
}
.lesson-hero__title {
  font-size: clamp(2rem, 5vw, 3.2rem); font-weight: 800;
  letter-spacing: -0.025em; margin: 0 0 12px; color: var(--ink);
}
.lesson-hero__sub { font-size: 1.05rem; color: var(--ink-soft); max-width: 60ch; margin: 0 0 22px; }
.lesson-hero__meta { display: flex; flex-wrap: wrap; gap: 8px; }
.lesson-hero__meta-pill {
  background: rgba(255,255,255,0.85); border: 1px solid var(--border);
  color: var(--ink-soft); font-weight: 600; font-size: 0.85rem;
  padding: 6px 12px; border-radius: 999px;
}

/* ---------- 2. Lesson body — section blocks ---------- */
.lesson-body { max-width: 880px; margin: 0 auto; padding: 40px 24px 72px; }

.lesson-section {
  background: var(--surface); border: 1px solid var(--border);
  border-radius: var(--radius-lg); padding: 28px 28px 24px;
  margin-bottom: 22px; box-shadow: var(--shadow); scroll-margin-top: 16px;
}
.lesson-section__head {
  display: flex; align-items: baseline; gap: 14px; flex-wrap: wrap;
  border-bottom: 1px solid var(--border); padding-bottom: 14px; margin-bottom: 18px;
}
.lesson-section__num {
  font-family: var(--font-mono); font-size: 0.85rem; font-weight: 700;
  letter-spacing: 0.08em; color: var(--accent, var(--brand));
  background: var(--accent-soft, var(--brand-soft)); padding: 4px 10px; border-radius: 999px;
}
.lesson-section__title {
  font-size: 1.4rem; font-weight: 800; letter-spacing: -0.02em;
  color: var(--ink); flex: 1; margin: 0;
}
.lesson-section__time {
  font-family: var(--font-mono); font-size: 0.78rem; font-weight: 600;
  color: var(--muted); letter-spacing: 0.04em;
}
.lesson-section__body p { margin: 0 0 12px; }
.lesson-section__body p:last-child { margin-bottom: 0; }
.lesson-section__body h3 {
  font-size: 1.05rem; font-weight: 700; margin: 18px 0 10px;
  color: var(--ink); letter-spacing: -0.005em;
}
.lesson-section__body ul:not(.goals) {
  list-style: disc; padding-left: 22px; margin: 0 0 12px; color: var(--ink-soft);
}
.lesson-section__body ul:not(.goals) li { margin-bottom: 4px; }
.lesson-section__body ol {
  list-style: decimal; padding-left: 22px; margin: 0 0 12px; color: var(--ink-soft);
}
.lesson-section__body ol li { margin-bottom: 6px; }

/* Learning-goals tick list */
.goals { display: grid; gap: 10px; margin: 0; padding: 0; list-style: none; }
.goals li {
  position: relative; padding: 12px 14px 12px 46px;
  background: var(--accent-soft, var(--brand-soft)); border-radius: var(--radius-sm);
  color: var(--ink); font-weight: 500;
}
.goals li::before {
  content: "\2713"; position: absolute; left: 14px; top: 50%;
  transform: translateY(-50%); width: 22px; height: 22px; border-radius: 999px;
  background: var(--accent, var(--brand)); color: #fff; font-size: 0.78rem;
  font-weight: 800; display: inline-flex; align-items: center; justify-content: center;
}

/* ---------- 3. Code blocks (reused for L3–L4 Python via <PyCode>) ---------- */
pre.code-block {
  font-family: var(--font-mono); font-size: 0.88rem;
  background: var(--code-bg); color: var(--code-ink);
  border-radius: var(--radius); padding: 16px 18px; overflow-x: auto;
  line-height: 1.6; margin: 12px 0;
}
pre.code-block--py {
  background: #000000; color: #d4d4d4; border: 1px solid #2d2d2d;
}
pre.code-block--py .py-kw      { color: #569cd6; }
pre.code-block--py .py-builtin { color: #4ec9b0; }
pre.code-block--py .py-fn      { color: #dcdcaa; }
pre.code-block--py .py-name    { color: #9cdcfe; }
pre.code-block--py .py-string  { color: #ce9178; }
pre.code-block--py .py-number  { color: #b5cea8; }
pre.code-block--py .py-comment { color: #6a9955; font-style: italic; }
pre.code-block--py .py-op      { color: #d4d4d4; }
pre.code-block--output {
  background: #111827; color: #FBBF24; border-left: 4px solid var(--game-2);
}
.code-block-label {
  font-family: var(--font-mono); font-size: 0.74rem; font-weight: 700;
  letter-spacing: 0.08em; text-transform: uppercase; color: var(--muted);
  margin: 14px 0 4px !important;
}
.lesson-body code { background: #F1F5F9; color: var(--ink); font-size: 0.86em; }

/* ---------- 4. Callouts ---------- */
.callout {
  border-left: 4px solid var(--accent, var(--brand));
  background: var(--accent-soft, var(--brand-soft));
  padding: 14px 16px; border-radius: var(--radius-sm); margin: 14px 0;
}
.callout strong {
  display: block; font-size: 0.78rem; letter-spacing: 0.08em;
  text-transform: uppercase; color: var(--accent-dark, var(--brand-deep)); margin-bottom: 4px;
}
.callout p:last-child { margin-bottom: 0; }
/* Safety callout — amber, used for the responsible-use notes */
.callout--safety {
  border-left-color: var(--game-2);
  background: var(--game-soft);
}
.callout--safety strong { color: #92400E; }

/* ---------- 5. Try-It-Yourself exercises ---------- */
.exercise {
  border: 1px dashed var(--border); border-radius: var(--radius-sm);
  padding: 16px 18px; margin: 12px 0; background: #FAFBFE;
}
.exercise__head {
  display: flex; align-items: center; gap: 10px; margin-bottom: 8px;
  font-weight: 700; color: var(--ink);
}
.exercise__num {
  font-family: var(--font-mono); font-size: 0.78rem; font-weight: 700;
  background: var(--accent, var(--brand)); color: #fff;
  padding: 3px 10px; border-radius: 999px; letter-spacing: 0.04em;
}
.exercise details { margin-top: 8px; }
.exercise summary {
  cursor: pointer; font-size: 0.88rem; color: var(--accent-dark, var(--brand-deep));
  font-weight: 600; user-select: none;
}
.exercise summary:hover { text-decoration: underline; }
.exercise[open] summary { margin-bottom: 6px; }

/* ---------- 6. PromptCard — AI chat exchange ---------- */
.prompt-card {
  border: 1px solid var(--border); border-radius: var(--radius);
  background: #fff; padding: 14px 14px 6px; margin: 14px 0;
  display: grid; gap: 10px;
}
.prompt-card__turn { display: grid; gap: 4px; }
.prompt-card__who {
  font-family: var(--font-mono); font-size: 0.7rem; font-weight: 700;
  letter-spacing: 0.08em; text-transform: uppercase; color: var(--muted);
}
.prompt-card__bubble {
  margin: 0 !important; padding: 12px 14px; border-radius: 14px;
  white-space: pre-wrap; line-height: 1.55; font-size: 0.96rem;
}
.prompt-card__turn--you .prompt-card__bubble {
  background: var(--accent-soft, var(--brand-soft));
  color: var(--ink);
  border: 1px solid color-mix(in srgb, var(--accent, var(--brand)) 35%, var(--border));
  border-bottom-left-radius: 4px;
}
.prompt-card__turn--ai .prompt-card__bubble {
  background: #F1F5F9; color: var(--ink);
  border: 1px solid var(--border); border-bottom-right-radius: 4px;
}
.prompt-card__note {
  margin: 0 0 6px !important; font-size: 0.84rem; color: var(--muted); font-style: italic;
}
/* Weak / "before" prompt — deliberately muted so a poor prompt doesn't look polished */
.prompt-card--weak { background: #FAFAFA; border-style: dashed; opacity: 0.92; }
.prompt-card--weak .prompt-card__turn--you .prompt-card__bubble {
  background: #F1F5F9; color: var(--ink-soft);
  border-color: var(--border);
}
.prompt-card--weak::before {
  content: "⚠ weak prompt"; font-family: var(--font-mono); font-size: 0.66rem;
  font-weight: 700; letter-spacing: 0.08em; text-transform: uppercase;
  color: #92400E; background: var(--game-soft); border: 1px solid var(--game-border);
  padding: 2px 8px; border-radius: 999px; justify-self: start;
}
/* Side-by-side weak-vs-strong comparison */
.prompt-compare { display: grid; gap: 14px; margin: 14px 0; }
@media (min-width: 760px) {
  .prompt-compare { grid-template-columns: 1fr 1fr; align-items: start; }
  .prompt-compare .prompt-card { margin: 0; }
}

/* ---------- 7. Concept diagram figures ---------- */
.ai-diagram {
  margin: 16px 0; padding: 16px; background: #FAFBFE;
  border: 1px solid var(--border); border-radius: var(--radius); text-align: center;
}
.ai-diagram svg { max-width: 100%; height: auto; }
.ai-diagram figcaption {
  margin-top: 10px; font-size: 0.86rem; color: var(--muted); font-style: italic;
}

/* ---------- 8. Homework answer gate ---------- */
.homework-gate {
  margin-top: 18px; padding: 16px 18px; background: rgba(255, 255, 255, 0.7);
  border: 1px dashed var(--game-border); border-radius: var(--radius);
}
.homework-gate__btn {
  font: inherit; font-weight: 700;
  background: linear-gradient(135deg, var(--game-1) 0%, var(--game-2) 100%);
  color: #fff; border: 0; padding: 10px 20px; border-radius: 999px; cursor: pointer;
  letter-spacing: -0.005em; transition: transform .15s ease, box-shadow .15s ease, filter .15s ease;
}
.homework-gate__btn:hover { transform: translateY(-1px); box-shadow: var(--shadow); filter: brightness(1.05); }
.homework-gate__btn:focus-visible { outline: 3px solid var(--game-2); outline-offset: 2px; }
.homework-gate__form { margin: 0; }
.homework-gate__label { display: block; font-weight: 600; font-size: 0.92rem; color: var(--ink); margin-bottom: 8px; }
.homework-gate__row { display: flex; gap: 8px; flex-wrap: wrap; }
.homework-gate__row input {
  flex: 1; min-width: 200px; padding: 10px 14px; font: inherit; background: #fff;
  color: var(--ink); border: 1px solid var(--border); border-radius: var(--radius-sm);
  outline: 0; transition: border-color .15s ease, box-shadow .15s ease;
}
.homework-gate__row input:focus {
  border-color: var(--game-2);
  box-shadow: 0 0 0 3px color-mix(in srgb, var(--game-2) 25%, transparent);
}
.homework-gate__submit {
  font: inherit; font-weight: 700; background: var(--game-2); color: #fff; border: 0;
  padding: 10px 20px; border-radius: var(--radius-sm); cursor: pointer; transition: filter .15s ease;
}
.homework-gate__submit:hover { filter: brightness(1.08); }
.homework-gate__error { margin: 8px 0 0 !important; color: var(--challenge-1); font-size: 0.9rem; font-weight: 600; }
.homework-gate__answer {
  background: var(--surface); border: 1px solid var(--border);
  border-radius: var(--radius); padding: 16px 18px; margin-top: 12px;
}
.homework-gate__answer h3 {
  margin: 0 0 8px !important; font-size: 1rem !important; color: var(--game-2);
  letter-spacing: 0.04em; text-transform: uppercase; font-family: var(--font-mono);
}
.homework-gate__answer p:last-child { margin-bottom: 0; }
.homework-gate__hint { display: block; margin-top: 8px; font-size: 0.86rem; color: var(--muted); font-style: italic; }

/* ---------- 9. Mini-challenge & homework section variants ---------- */
.lesson-section--challenge {
  background: linear-gradient(180deg, var(--challenge-soft) 0%, var(--surface) 80%);
  border-color: var(--challenge-border);
}
.lesson-section--challenge .lesson-section__num { background: #fff; color: var(--challenge-1); }
.lesson-section--homework {
  background: linear-gradient(180deg, var(--game-soft) 0%, var(--surface) 80%);
  border-color: var(--game-border);
}
.lesson-section--homework .lesson-section__num { background: #fff; color: var(--game-2); }

/* ---------- 10. Vocabulary card ---------- */
.vocab-card {
  background: var(--accent-soft, var(--brand-soft));
  border: 1px solid color-mix(in srgb, var(--accent, var(--brand)) 35%, var(--border));
  border-radius: var(--radius); padding: 18px 20px; margin: 14px 0;
}
.vocab-card h4 {
  font-size: 0.78rem; font-weight: 700; letter-spacing: 0.08em;
  text-transform: uppercase; color: var(--accent-dark, var(--brand-deep)); margin: 0 0 10px;
}
.vocab-card dl { margin: 0; display: grid; gap: 10px; }
.vocab-card dt { font-family: var(--font-mono); font-weight: 700; color: var(--ink); }
.vocab-card dd { margin: 2px 0 0; color: var(--ink-soft); font-size: 0.94rem; }

/* ---------- 11. Lesson foot — prev / next ---------- */
.lesson-foot { display: flex; justify-content: space-between; gap: 14px; flex-wrap: wrap; margin-top: 24px; }
.lesson-foot__btn {
  flex: 1; min-width: 220px; padding: 16px 18px; border: 1px solid var(--border);
  background: var(--surface); border-radius: var(--radius); text-decoration: none;
  color: var(--ink); display: block;
  transition: transform .15s ease, border-color .15s ease, box-shadow .15s ease;
}
.lesson-foot__btn:hover {
  transform: translateY(-2px); border-color: var(--accent, var(--brand));
  box-shadow: var(--shadow); text-decoration: none;
}
.lesson-foot__btn[aria-disabled="true"] { opacity: 0.55; pointer-events: none; }
.lesson-foot__dir {
  display: block; font-family: var(--font-mono); font-size: 0.72rem;
  letter-spacing: 0.1em; text-transform: uppercase; color: var(--muted); margin-bottom: 4px;
}
.lesson-foot__title { display: block; font-weight: 700; font-size: 1rem; color: var(--ink); }
.lesson-foot__btn--next { text-align: right; }

/* ---------- 12. Responsive ---------- */
@media (max-width: 720px) {
  .lesson-hero__inner    { padding: 44px 20px 32px; }
  .lesson-body           { padding: 28px 16px 56px; }
  .lesson-section        { padding: 22px 18px 18px; }
  .lesson-section__head  { gap: 8px; }
  .lesson-section__title { font-size: 1.15rem; }
  .lesson-foot           { flex-direction: column; }
  .lesson-foot__btn--next { text-align: left; }
}

/* ---------- 13. Print ---------- */
@media print {
  .lesson-hero      { background: #fff !important; }
  .lesson-section   { box-shadow: none; break-inside: avoid; }
  .lesson-foot, .topnav-back { display: none; }
  pre.code-block, pre.code-block--output {
    background: #f5f5f5 !important; color: #000 !important; border: 1px solid #ddd !important;
  }
  .homework-gate { display: none !important; }
}