/* learn.css — Socratii learn library page styles (uses tokens from style.css) */

/* ============ PAGE INTRO ============ */
.learn-hero {
  padding-block: clamp(var(--space-12), 7vw, var(--space-20)) var(--space-10);
  border-bottom: 1px solid var(--color-divider);
}
.learn-hero-copy h1 {
  font-size: var(--text-2xl);
  font-weight: 700;
  margin-top: var(--space-3);
}
.learn-hero-copy p {
  margin-top: var(--space-5);
  font-size: var(--text-base);
  color: var(--color-text-muted);
  max-width: 74ch;
}
.learn-hero-copy p strong {
  color: var(--color-text);
}

/* ============ JUMP NAV (mirrors .calc-jumpnav) ============ */
.learn-jumpnav {
  margin-top: var(--space-8);
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: var(--space-2) var(--space-3);
  padding: var(--space-4) var(--space-5);
  background: var(--color-surface);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-lg);
}
.learn-jumpnav-label {
  font-size: var(--text-xs);
  font-weight: 600;
  letter-spacing: 0.06em;
  text-transform: uppercase;
  color: var(--color-text-faint);
  margin-right: var(--space-1);
}
.learn-jumpnav a {
  display: inline-flex;
  align-items: center;
  gap: var(--space-2);
  font-size: var(--text-sm);
  font-weight: 600;
  color: var(--color-primary);
  text-decoration: none;
  padding: var(--space-1) var(--space-2);
  border-radius: var(--radius-sm);
}
.learn-jumpnav a:hover {
  text-decoration: underline;
  background: var(--color-surface-offset);
}
.learn-jumpnav span[aria-hidden] {
  color: var(--color-text-faint);
}
.learn-jumpnav-dot {
  width: 8px;
  height: 8px;
  border-radius: var(--radius-full);
  flex-shrink: 0;
  background: var(--color-gold);
}

/* ============ CATEGORY SECTIONS ============ */
.learn-category {
  border-bottom: 1px solid var(--color-divider);
  scroll-margin-top: var(--space-20);
}
.learn-category--alt {
  background: var(--color-surface-2);
}
.learn-category:last-of-type {
  border-bottom: none;
}

.learn-category-head {
  max-width: 720px;
  margin-bottom: var(--space-10);
  display: flex;
  align-items: flex-start;
  gap: var(--space-4);
}
.learn-category-icon {
  flex-shrink: 0;
  width: 48px;
  height: 48px;
  border-radius: var(--radius-lg);
  display: inline-flex;
  align-items: center;
  justify-content: center;
  background: var(--color-primary-highlight);
  color: var(--color-primary);
  margin-top: var(--space-1);
}
.learn-category-icon svg {
  width: 24px;
  height: 24px;
}
.learn-category-head-copy .eyebrow {
  margin-bottom: var(--space-1);
}
.learn-category-head h2 {
  font-size: var(--text-xl);
  font-weight: 700;
}
.learn-category-head p {
  margin-top: var(--space-3);
  color: var(--color-text-muted);
  font-size: var(--text-base);
}

/* ============ SUBCATEGORY CARD GRID ============ */
.subtopic-grid {
  display: grid;
  gap: var(--space-5);
  grid-template-columns: 1fr;
}
@media (min-width: 560px) {
  .subtopic-grid {
    grid-template-columns: repeat(2, 1fr);
  }
}
@media (min-width: 1080px) {
  .subtopic-grid {
    grid-template-columns: repeat(3, 1fr);
  }
}

.subtopic-card {
  background: var(--color-surface);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-lg);
  padding: var(--space-5) var(--space-6);
  display: flex;
  flex-direction: column;
  transition:
    box-shadow var(--transition-interactive),
    transform var(--transition-interactive),
    border-color var(--transition-interactive);
}
.subtopic-card:hover,
.subtopic-card:has(.lesson-summary:focus-visible) {
  box-shadow: var(--shadow-md);
  border-color: oklch(from var(--color-primary) l c h / 0.3);
  transform: translateY(-2px);
}

.subtopic-card-top {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: var(--space-3);
}
.subtopic-card h3 {
  font-size: var(--text-base);
  font-weight: 700;
}
.subtopic-status {
  flex-shrink: 0;
  display: inline-flex;
  align-items: center;
  font-size: var(--text-xs);
  font-weight: 600;
  letter-spacing: 0.03em;
  text-transform: uppercase;
  color: var(--color-gold);
  background: var(--color-gold-highlight);
  border-radius: var(--radius-full);
  padding: var(--space-1) var(--space-3);
  white-space: nowrap;
}
.subtopic-card p {
  color: var(--color-text-muted);
  font-size: var(--text-sm);
}

/* ============ LESSON ACCORDION (details/summary disclosure) ============ */
.lesson-disclosure {
  display: flex;
  flex-direction: column;
  gap: var(--space-2);
}

/* The <summary> reuses .subtopic-card-top layout but needs button-like
   semantics: full width, no default marker, keyboard-focusable. */
.lesson-summary {
  cursor: pointer;
  list-style: none;
  -webkit-tap-highlight-color: transparent;
  border-radius: var(--radius-sm);
}
.lesson-summary::-webkit-details-marker {
  display: none;
}
.lesson-summary::marker {
  content: '';
}

.lesson-toggle-affordance {
  flex-shrink: 0;
  display: inline-flex;
  align-items: center;
  gap: var(--space-1);
  font-size: var(--text-xs);
  font-weight: 600;
  letter-spacing: 0.03em;
  text-transform: uppercase;
  color: var(--color-primary);
  background: var(--color-primary-highlight);
  border-radius: var(--radius-full);
  padding: var(--space-1) var(--space-3);
  white-space: nowrap;
  transition:
    background var(--transition-interactive),
    color var(--transition-interactive);
}
.lesson-toggle-icon {
  width: 12px;
  height: 12px;
  transition: transform var(--transition-interactive);
}
.lesson-disclosure[open] > .lesson-summary .lesson-toggle-icon {
  transform: rotate(180deg);
}
.lesson-disclosure[open] > .lesson-summary .lesson-toggle-affordance {
  background: var(--color-primary);
  color: var(--color-text-inverse);
}
.lesson-summary:hover .lesson-toggle-affordance {
  background: var(--color-primary);
  color: var(--color-text-inverse);
}

/* Smooth expand/collapse via grid-template-rows trick (no JS needed,
   works with native <details>/<summary> because the row track only
   needs the [open] attribute as a hook). */
.lesson-panel {
  display: grid;
  grid-template-rows: 0fr;
  overflow: hidden;
  transition: grid-template-rows 320ms var(--ease-out-expo);
}
.lesson-disclosure[open] > .lesson-panel {
  grid-template-rows: 1fr;
}
.lesson-panel-inner {
  min-height: 0;
  overflow: hidden;
}
.lesson-disclosure[open] > .lesson-panel .lesson-panel-inner {
  overflow: visible;
}

.lesson-body {
  padding-top: var(--space-4);
  border-top: 1px solid var(--color-divider);
  margin-top: var(--space-2);
  display: flex;
  flex-direction: column;
  gap: var(--space-3);
}
.lesson-body p {
  color: var(--color-text);
  font-size: var(--text-sm);
  line-height: 1.65;
}

.lesson-takeaways {
  margin-top: var(--space-4);
  background: var(--color-surface-2);
  border: 1px solid var(--color-divider);
  border-radius: var(--radius-md);
  padding: var(--space-4);
}
.lesson-takeaways h4 {
  font-size: var(--text-xs);
  font-weight: 700;
  letter-spacing: 0.04em;
  text-transform: uppercase;
  color: var(--color-primary);
  margin-bottom: var(--space-2);
}
.lesson-takeaways ul {
  display: flex;
  flex-direction: column;
  gap: var(--space-2);
  padding-left: var(--space-5);
}
.lesson-takeaways li {
  color: var(--color-text-muted);
  font-size: var(--text-sm);
  line-height: 1.55;
  list-style: disc;
}
.lesson-takeaways li::marker {
  color: var(--color-gold);
}

/* ============ CROSS-LINK: "Related calculator" (lesson -> calculator) ============ */
.lesson-relcalcs {
  margin-top: var(--space-4);
  padding-top: var(--space-4);
  border-top: 1px solid var(--color-divider);
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: var(--space-2) var(--space-2);
}
.lesson-relcalcs-label {
  font-size: var(--text-xs);
  font-weight: 700;
  letter-spacing: 0.04em;
  text-transform: uppercase;
  color: var(--color-text-faint);
  margin-right: var(--space-1);
  flex-basis: 100%;
}
.lesson-relcalc {
  display: inline-flex;
  align-items: center;
  gap: var(--space-1);
  font-size: var(--text-xs);
  font-weight: 600;
  color: var(--color-primary);
  background: var(--color-primary-highlight);
  border-radius: var(--radius-full);
  padding: var(--space-1) var(--space-3);
  text-decoration: none;
  max-width: 100%;
  transition:
    background var(--transition-interactive),
    color var(--transition-interactive);
}
.lesson-relcalc-icon {
  width: 12px;
  height: 12px;
  flex-shrink: 0;
}
.lesson-relcalc:hover,
.lesson-relcalc:focus-visible {
  background: var(--color-primary);
  color: var(--color-text-inverse);
}
.lesson-relcalc:focus-visible {
  outline: 2px solid var(--color-primary);
  outline-offset: 2px;
}

@media (prefers-reduced-motion: reduce) {
  .lesson-panel,
  .lesson-toggle-icon {
    transition: none;
  }
}

/* ============ CATEGORY DIVIDER LABEL (mobile breathing room helper) ============ */
.learn-category .container > .learn-category-head {
  scroll-margin-top: var(--space-20);
}

@media (max-width: 480px) {
  .learn-category-head {
    gap: var(--space-3);
  }
  .learn-category-icon {
    width: 40px;
    height: 40px;
  }
  .learn-category-icon svg {
    width: 20px;
    height: 20px;
  }
  .subtopic-card {
    padding: var(--space-5);
  }
}

/* ============ CLOSING NOTE ============ */
.learn-closing {
  padding-block: clamp(var(--space-10), 6vw, var(--space-16));
}
.learn-closing .container {
  max-width: 760px;
  text-align: center;
}
.learn-closing p {
  color: var(--color-text-muted);
  font-size: var(--text-sm);
}