/* ═══════════════════════════════════════════════════════════════
   RONNY BEST MATHEMATICS — index.css  v4.1  (CORRECTED)
   Navy + Bisque palette · Playfair Display + Lora + DM Sans
   CBC-aligned · AdSense-compliant · Full responsive
   Fixes: search-results clipping on mobile, anim-hidden/visible
          classes, search bar z-index on mobile, overflow visible
   ═══════════════════════════════════════════════════════════════ */

/* ─── DESIGN TOKENS ─── */
:root {
  --navy-950:  #070f1e;
  --navy-900:  #0a1628;
  --navy-800:  #0f2040;
  --navy-700:  #1a3560;
  --navy-600:  #1e4d8c;
  --navy-400:  #4a80c8;

  --bisque:        #ffe4c4;
  --bisque-light:  #fff3e8;
  --bisque-mid:    #f5ddb8;
  --bisque-dark:   #e8b87a;
  --bisque-deep:   #c8832a;

  --cream:     #faf7f2;
  --cream-100: #f4efe5;
  --cream-200: #e8dfd0;
  --cream-300: #d5cfc4;

  --ink:       #1a1612;
  --ink-70:    #3a3028;
  --ink-50:    #5a4e42;
  --ink-30:    #9a8a78;

  --green:     #1e6e36;
  --green-bg:  #e8f5ec;
  --green-dark:#155228;
  --red:       #b91c1c;
  --red-bg:    #fef2f2;

  --white:     #ffffff;

  --font-display: 'Playfair Display', Georgia, serif;
  --font-serif:   'Lora', Georgia, serif;
  --font-ui:      'DM Sans', system-ui, sans-serif;
  --font-mono:    'JetBrains Mono', 'Courier New', monospace;

  --radius-sm:  8px;
  --radius-md:  14px;
  --radius-lg:  20px;
  --radius-xl:  28px;
  --radius-pill:9999px;

  --shadow-xs:  0 1px 3px rgba(10,22,40,.07);
  --shadow-sm:  0 2px 10px rgba(10,22,40,.10);
  --shadow-md:  0 6px 24px rgba(10,22,40,.13);
  --shadow-lg:  0 12px 40px rgba(10,22,40,.17);
  --shadow-navy:0 8px 32px rgba(10,22,40,.28);

  --transition: .24s cubic-bezier(.4,0,.2,1);

  --max-w: 1200px;
  --pad-x: clamp(1.2rem, 5%, 5rem);
  --section-py: clamp(3rem, 6vw, 5rem);
}

/* ─── RESET ─── */
*,*::before,*::after { box-sizing: border-box; margin: 0; padding: 0; }
html { font-size: 16px; scroll-behavior: smooth; -webkit-text-size-adjust: 100%; }
body {
  font-family: var(--font-ui);
  background: var(--cream);
  color: var(--ink);
  line-height: 1.7;
  min-height: 100vh;
  display: flex;
  flex-direction: column;
}
img { max-width: 100%; height: auto; display: block; }
a { color: var(--navy-700); transition: color var(--transition); }
a:hover { color: var(--navy-900); }
ul, ol { list-style: none; }
h1,h2,h3,h4,h5 {
  font-family: var(--font-display);
  line-height: 1.2;
  color: var(--navy-900);
  letter-spacing: -.015em;
}
p { color: var(--ink-50); }

/* ─── SKIP LINK ─── */
.skip-link {
  position: absolute;
  top: -100%;
  left: 1rem;
  background: var(--bisque-deep);
  color: #fff;
  padding: .6rem 1.2rem;
  border-radius: var(--radius-sm);
  font-weight: 700;
  z-index: 9999;
  text-decoration: none;
  transition: top .2s;
}
.skip-link:focus { top: 1rem; }

/* ─── SCREEN READER ONLY ─── */
.sr-only {
  position: absolute;
  width: 1px; height: 1px;
  padding: 0; margin: -1px;
  overflow: hidden;
  clip: rect(0,0,0,0);
  white-space: nowrap;
  border: 0;
}

/* ─── FOCUS RING ─── */
:focus-visible {
  outline: 3px solid var(--bisque-deep);
  outline-offset: 3px;
  border-radius: 4px;
}

/* ─── LINK BUTTON ─── */
.link-btn {
  background: none;
  border: none;
  color: var(--navy-700);
  font-family: var(--font-ui);
  font-size: inherit;
  font-weight: 600;
  cursor: pointer;
  text-decoration: underline;
  padding: 0;
}
.link-btn:hover { color: var(--navy-900); }

/* ─── OUTLINE NAVY BUTTON ─── */
.btn-outline-navy {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  font-family: var(--font-ui);
  font-weight: 700;
  font-size: .9rem;
  padding: .7rem 1.6rem;
  border-radius: var(--radius-pill);
  border: 2px solid var(--navy-700);
  color: var(--navy-700);
  text-decoration: none;
  transition: var(--transition);
  margin-top: 1rem;
}
.btn-outline-navy:hover {
  background: var(--navy-700);
  color: var(--bisque-light);
}

/* ─── FIX: Scroll animation classes (replaces inline styles in JS) ─── */
.anim-hidden {
  opacity: 0;
  transform: translateY(16px);
}
.anim-visible {
  opacity: 1;
  transform: translateY(0);
  transition: opacity .4s ease, transform .4s ease;
}

/* ─── FIX: Search result highlight mark ─── */
.sr-item-name mark {
  background: rgba(200,131,42,.25);
  color: var(--bisque-light);
  border-radius: 2px;
  padding: 0 2px;
}

/* ═══════════════════════════════════════════════
   HEADER
═══════════════════════════════════════════════ */
.site-header {
  background: linear-gradient(160deg, var(--navy-950) 0%, var(--navy-800) 55%, var(--navy-700) 100%);
  padding: 24px var(--pad-x);
  border-bottom: 3px solid var(--bisque-dark);
  position: relative;
  overflow: hidden;
}
.site-header::before {
  content: "∑ ∫ π √ ∞";
  position: absolute; top: 8%; right: 4%;
  font-family: var(--font-mono);
  font-size: 4rem; font-weight: 700;
  color: rgba(255,228,196,.05);
  letter-spacing: .3em;
  transform: rotate(10deg);
  pointer-events: none;
  user-select: none;
}
.header-inner {
  max-width: var(--max-w);
  margin: 0 auto;
  display: flex;
  align-items: center;
  justify-content: space-between;
  flex-wrap: wrap;
  gap: 12px;
}
.brand-logo {
  display: flex;
  align-items: center;
  gap: 12px;
  text-decoration: none;
  color: inherit;
}
.brand-sigma {
  width: 46px; height: 46px;
  background: var(--bisque-deep);
  color: #fff;
  font-family: var(--font-display);
  font-size: 1.5rem;
  font-weight: 900;
  display: flex; align-items: center; justify-content: center;
  border-radius: var(--radius-sm);
  flex-shrink: 0;
  box-shadow: 0 4px 14px rgba(200,131,42,.35);
}
.brand-text {
  font-family: var(--font-display);
  font-size: clamp(1.1rem, 2.5vw, 1.45rem);
  font-weight: 700;
  color: var(--bisque-light);
  letter-spacing: -.01em;
  line-height: 1.2;
}
.brand-text em {
  display: block;
  font-style: normal;
  color: var(--bisque-dark);
  font-size: .85em;
  font-weight: 400;
  font-family: var(--font-serif);
}
.brand-tagline {
  font-size: .72rem;
  font-weight: 600;
  letter-spacing: .1em;
  text-transform: uppercase;
  color: rgba(255,228,196,.45);
  margin-top: 5px;
}
.welcome-pill {
  font-family: var(--font-ui);
  font-size: .82rem;
  font-weight: 600;
  color: var(--bisque-light);
  background: rgba(255,228,196,.1);
  border: 1px solid rgba(255,228,196,.2);
  padding: .4rem 1.2rem;
  border-radius: var(--radius-pill);
  letter-spacing: .03em;
}

/* ═══════════════════════════════════════════════
   NAVIGATION
═══════════════════════════════════════════════ */
.main-nav {
  background: var(--navy-900);
  position: sticky; top: 0; z-index: 500;
  box-shadow: 0 4px 20px rgba(0,0,0,.35);
  border-bottom: 2px solid var(--bisque-dark);
  /* FIX: allow search-results dropdown to overflow on desktop */
  overflow: visible;
}
.nav-inner {
  max-width: var(--max-w);
  margin: 0 auto;
  padding: 0 var(--pad-x);
  position: relative;
  /* FIX: must be visible so .search-results isn't clipped */
  overflow: visible;
}

/* Mobile top bar */
.nav-mobile-bar {
  display: none;
  align-items: center;
  justify-content: space-between;
  padding: .7rem 0;
}
.nav-mobile-brand {
  font-family: var(--font-display);
  font-size: 1.1rem;
  font-weight: 700;
  color: var(--bisque-light);
}
.nav-mobile-brand em { font-style: normal; color: var(--bisque-dark); }
.nav-mobile-actions { display: flex; align-items: center; gap: 8px; }

/* Hamburger */
.nav-hamburger {
  background: none;
  border: 1px solid rgba(255,228,196,.25);
  border-radius: var(--radius-sm);
  padding: 6px 8px;
  cursor: pointer;
  display: flex;
  flex-direction: column;
  gap: 4px;
  transition: var(--transition);
}
.nav-hamburger:hover { background: rgba(255,228,196,.1); }
.ham-line {
  display: block;
  width: 20px; height: 2px;
  background: var(--bisque);
  border-radius: 2px;
  transition: transform .25s, opacity .25s;
}
.nav-hamburger[aria-expanded="true"] .ham-line:nth-child(1) { transform: translateY(6px) rotate(45deg); }
.nav-hamburger[aria-expanded="true"] .ham-line:nth-child(2) { opacity: 0; }
.nav-hamburger[aria-expanded="true"] .ham-line:nth-child(3) { transform: translateY(-6px) rotate(-45deg); }

/* Search toggle button */
.nav-search-toggle {
  background: none;
  border: 1px solid rgba(255,228,196,.25);
  border-radius: var(--radius-sm);
  padding: 7px;
  cursor: pointer;
  color: var(--bisque);
  display: flex; align-items: center; justify-content: center;
  transition: var(--transition);
}
.nav-search-toggle:hover { background: rgba(255,228,196,.1); }

/* Search bar */
.nav-search-bar {
  padding: .6rem 0 .4rem;
  position: relative;
  /* FIX: ensure search bar sits above the nav list on mobile */
  z-index: 510;
}
.nsb-inner {
  display: flex;
  align-items: center;
  gap: 10px;
  background: rgba(255,255,255,.08);
  border: 1px solid rgba(255,228,196,.2);
  border-radius: var(--radius-md);
  padding: .55rem 1rem;
}
.nsb-inner svg { color: rgba(255,228,196,.4); flex-shrink: 0; }
#siteSearch {
  flex: 1;
  background: none;
  border: none;
  outline: none;
  font-family: var(--font-ui);
  font-size: .9rem;
  color: var(--bisque-light);
  min-width: 0;
}
#siteSearch::placeholder { color: rgba(255,228,196,.35); }
#searchClear {
  background: none;
  border: none;
  color: rgba(255,228,196,.4);
  cursor: pointer;
  font-size: .85rem;
  padding: 2px 6px;
  border-radius: 4px;
}
#searchClear:hover { color: var(--bisque); }

/* Search results dropdown
   FIX: use position:fixed on mobile so it escapes any clipping parent.
   On desktop, absolute is fine because .nav-inner is overflow:visible. */
.search-results {
  position: absolute;
  top: calc(100% + 4px);
  left: 0; right: 0;
  background: var(--navy-800);
  border: 1px solid rgba(255,228,196,.15);
  border-radius: var(--radius-md);
  z-index: 700;
  max-height: 320px;
  overflow-y: auto;
  box-shadow: var(--shadow-lg);
}
.sr-item {
  display: flex;
  align-items: center;
  gap: 12px;
  padding: .75rem 1rem;
  text-decoration: none;
  color: var(--bisque-light);
  font-family: var(--font-ui);
  font-size: .88rem;
  border-bottom: 1px solid rgba(255,228,196,.06);
  transition: background var(--transition);
}
.sr-item:last-child { border-bottom: none; }
.sr-item:hover, .sr-item:focus { background: rgba(255,228,196,.08); }
.sr-item-icon {
  width: 32px; height: 32px;
  background: rgba(255,228,196,.1);
  border-radius: 6px;
  display: flex; align-items: center; justify-content: center;
  font-family: var(--font-mono);
  font-size: .85rem;
  color: var(--bisque-dark);
  flex-shrink: 0;
}
.sr-item-text { display: flex; flex-direction: column; gap: 2px; }
.sr-item-name { font-weight: 600; color: var(--bisque-light); }
.sr-item-type { font-size: .74rem; color: rgba(255,228,196,.4); }
.sr-no-results {
  padding: 1rem;
  text-align: center;
  color: rgba(255,228,196,.35);
  font-size: .88rem;
  font-family: var(--font-ui);
}

/* Nav list */
.nav-list {
  display: flex;
  flex-wrap: wrap;
  gap: 0;
  justify-content: center;
  align-items: center;
}
.nav-list > li { position: relative; }
.nav-list > li > a {
  display: flex;
  align-items: center;
  gap: 4px;
  padding: .85rem 1rem;
  color: rgba(255,228,196,.6);
  text-decoration: none;
  font-family: var(--font-ui);
  font-size: .84rem;
  font-weight: 500;
  letter-spacing: .02em;
  position: relative;
  transition: color var(--transition), background var(--transition);
  white-space: nowrap;
}
.nav-list > li > a::after {
  content: '';
  position: absolute; bottom: 0; left: 50%;
  width: 0; height: 3px;
  background: var(--bisque-dark);
  transition: width var(--transition), left var(--transition);
  border-radius: 3px 3px 0 0;
}
.nav-list > li > a:hover { color: rgba(255,228,196,.95); background: rgba(255,228,196,.05); }
.nav-list > li > a:hover::after,
.nav-list > li > a.active::after { width: 70%; left: 15%; }
.nav-list > li > a.active { color: var(--bisque); font-weight: 600; }
.nav-chevron { transition: transform var(--transition); flex-shrink: 0; }

/* Desktop dropdown */
.nav-dropdown {
  display: none;
  position: absolute;
  top: 100%; left: 0;
  background: var(--navy-800);
  border: 1px solid rgba(255,228,196,.12);
  border-radius: var(--radius-md);
  min-width: 200px;
  padding: .5rem;
  box-shadow: var(--shadow-lg);
  z-index: 600;
  animation: dropIn .18s ease;
}
@keyframes dropIn {
  from { opacity:0; transform:translateY(-6px); }
  to   { opacity:1; transform:translateY(0); }
}
.nav-has-dropdown:hover .nav-dropdown,
.nav-has-dropdown:focus-within .nav-dropdown { display: block; }
.nav-has-dropdown:hover .nav-chevron,
.nav-has-dropdown:focus-within .nav-chevron { transform: rotate(180deg); }

.nav-dropdown li a {
  display: block;
  padding: .6rem .9rem;
  color: rgba(255,228,196,.55);
  font-family: var(--font-ui);
  font-size: .85rem;
  font-weight: 400;
  text-decoration: none;
  border-radius: var(--radius-sm);
  transition: background var(--transition), color var(--transition);
}
.nav-dropdown li a:hover { background: rgba(255,228,196,.08); color: var(--bisque-light); }

/* ═══════════════════════════════════════════════
   SECTION SHARED
═══════════════════════════════════════════════ */
.site-main { flex: 1; }
.section-header { max-width: 700px; margin-bottom: 2.2rem; }
.section-header.centered { text-align: center; margin-left: auto; margin-right: auto; }
.section-eyebrow {
  display: inline-block;
  font-family: var(--font-ui);
  font-size: .7rem;
  font-weight: 700;
  letter-spacing: .12em;
  text-transform: uppercase;
  color: var(--bisque-deep);
  background: rgba(200,131,42,.1);
  border: 1px solid rgba(200,131,42,.2);
  padding: .28rem .85rem;
  border-radius: var(--radius-pill);
  margin-bottom: .6rem;
}
.section-header h2 {
  font-size: clamp(1.6rem, 3vw, 2.2rem);
  color: var(--navy-800);
  margin-bottom: .5rem;
}
.section-sub {
  font-family: var(--font-serif);
  font-size: .98rem;
  color: var(--ink-50);
  line-height: 1.75;
  font-style: italic;
}

/* ═══════════════════════════════════════════════
   HERO
═══════════════════════════════════════════════ */
.hero {
  background: linear-gradient(155deg, var(--navy-950) 0%, var(--navy-800) 50%, var(--navy-700) 100%);
  padding: clamp(3rem, 8vw, 5.5rem) var(--pad-x);
  display: grid;
  grid-template-columns: 1fr auto;
  gap: 40px;
  align-items: center;
  position: relative;
  overflow: hidden;
}
.hero-bg-grid {
  position: absolute; inset: 0;
  background-image:
    linear-gradient(rgba(255,228,196,.03) 1px, transparent 1px),
    linear-gradient(90deg, rgba(255,228,196,.03) 1px, transparent 1px);
  background-size: 60px 60px;
  pointer-events: none;
}
.hero-symbols { position: absolute; inset: 0; pointer-events: none; overflow: hidden; }
.hs {
  position: absolute;
  font-family: var(--font-mono);
  font-weight: 700;
  color: rgba(255,228,196,.04);
  line-height: 1;
  user-select: none;
}
.hs1 { font-size: 8rem; top: 5%; right: 42%; }
.hs2 { font-size: 5rem; top: 60%; left: 3%; }
.hs3 { font-size: 6rem; bottom: 5%; right: 20%; }
.hs4 { font-size: 4rem; top: 15%; left: 15%; }
.hs5 { font-size: 10rem; bottom: -10px; left: 55%; opacity: .025; }
.hs6 { font-size: 5rem; top: 40%; right: 5%; }

.hero-content { position: relative; z-index: 1; max-width: 640px; }
.hero-eyebrow {
  display: inline-flex;
  align-items: center;
  gap: 10px;
  font-family: var(--font-ui);
  font-size: .74rem;
  font-weight: 600;
  letter-spacing: .09em;
  text-transform: uppercase;
  color: var(--bisque-dark);
  margin-bottom: 18px;
  flex-wrap: wrap;
}
.eyebrow-dot {
  width: 5px; height: 5px;
  border-radius: 50%;
  background: var(--bisque-deep);
  flex-shrink: 0;
}
.hero h1 {
  font-family: var(--font-display);
  font-size: clamp(2.2rem, 5vw, 3.8rem);
  font-weight: 900;
  color: rgba(255,243,232,.95);
  letter-spacing: -.025em;
  line-height: 1.1;
  margin-bottom: 18px;
}
.hero-accent { color: var(--bisque-dark); display: block; }
.hero-sub {
  font-family: var(--font-serif);
  font-size: 1rem;
  color: rgba(255,228,196,.6);
  line-height: 1.8;
  margin-bottom: 28px;
  max-width: 520px;
}
.hero-sub strong { color: var(--bisque-dark); font-weight: 600; }
.hero-cta-row {
  display: flex;
  gap: 12px;
  flex-wrap: wrap;
  margin-bottom: 32px;
}
.btn-hero-primary {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  background: var(--bisque);
  color: var(--navy-900);
  font-family: var(--font-ui);
  font-weight: 700;
  font-size: .95rem;
  padding: .8rem 1.8rem;
  border-radius: var(--radius-pill);
  text-decoration: none;
  transition: var(--transition);
  box-shadow: 0 4px 20px rgba(200,131,42,.3);
  border: 2px solid var(--bisque-dark);
}
.btn-hero-primary:hover {
  background: var(--bisque-light);
  color: var(--navy-900);
  transform: translateY(-2px);
  box-shadow: 0 8px 28px rgba(200,131,42,.4);
}
.btn-hero-secondary {
  display: inline-flex;
  align-items: center;
  font-family: var(--font-ui);
  font-weight: 600;
  font-size: .95rem;
  padding: .8rem 1.6rem;
  border-radius: var(--radius-pill);
  border: 2px solid rgba(255,228,196,.3);
  color: rgba(255,228,196,.8);
  text-decoration: none;
  transition: var(--transition);
}
.btn-hero-secondary:hover {
  background: rgba(255,228,196,.1);
  border-color: rgba(255,228,196,.6);
  color: var(--bisque);
}
.hero-stats {
  display: flex;
  align-items: center;
  gap: 18px;
  flex-wrap: wrap;
}
.h-stat { text-align: center; }
.h-stat strong {
  display: block;
  font-family: var(--font-display);
  font-size: 1.55rem;
  font-weight: 900;
  color: var(--bisque-dark);
  line-height: 1.1;
}
.h-stat span {
  font-size: .7rem;
  font-weight: 600;
  letter-spacing: .07em;
  text-transform: uppercase;
  color: rgba(255,228,196,.4);
}
.h-stat-div {
  width: 1px; height: 32px;
  background: rgba(255,228,196,.15);
  flex-shrink: 0;
}

/* Hero formula card */
.hero-formula-card {
  position: relative; z-index: 1;
  background: rgba(255,255,255,.05);
  border: 1px solid rgba(255,228,196,.15);
  backdrop-filter: blur(8px);
  border-radius: var(--radius-lg);
  padding: 28px 32px;
  text-align: center;
  min-width: 240px;
  box-shadow: 0 8px 32px rgba(0,0,0,.25);
  flex-shrink: 0;
}
.hfc-label {
  font-family: var(--font-ui);
  font-size: .7rem;
  font-weight: 700;
  letter-spacing: .1em;
  text-transform: uppercase;
  color: rgba(255,228,196,.4);
  margin-bottom: 14px;
}
.hfc-formula {
  font-family: var(--font-mono);
  font-size: .95rem;
  color: var(--bisque);
  line-height: 2.2;
  white-space: nowrap;
}
.frac { display: inline-flex; flex-direction: column; align-items: center; gap: 2px; vertical-align: middle; }
.num { border-bottom: 1.5px solid var(--bisque-dark); padding-bottom: 2px; font-size: .82rem; }
.den { font-size: .82rem; }
.hfc-note {
  margin-top: 12px;
  font-size: .74rem;
  color: rgba(255,228,196,.35);
  font-family: var(--font-ui);
}

/* ═══════════════════════════════════════════════
   CBC ALIGNMENT BAND
═══════════════════════════════════════════════ */
.cbc-band {
  background: var(--navy-800);
  border-top: 1px solid rgba(255,228,196,.08);
  border-bottom: 2px solid var(--bisque-deep);
  padding: 1.6rem var(--pad-x);
}
.cbc-band-inner {
  max-width: var(--max-w);
  margin: 0 auto;
  display: flex;
  align-items: center;
  gap: 2rem;
  flex-wrap: wrap;
}
.cbc-band-title {
  font-family: var(--font-ui);
  font-size: .78rem;
  font-weight: 700;
  letter-spacing: .1em;
  text-transform: uppercase;
  color: rgba(255,228,196,.4);
  flex-shrink: 0;
  white-space: nowrap;
  margin: 0;
}
.cbc-pillars {
  display: flex;
  flex-wrap: wrap;
  gap: 1rem;
  flex: 1;
}
.cbc-pillar {
  display: flex;
  align-items: center;
  gap: 8px;
  background: rgba(255,228,196,.06);
  border: 1px solid rgba(255,228,196,.12);
  border-radius: var(--radius-pill);
  padding: .4rem 1rem .4rem .5rem;
}
.cbc-pillar-icon { font-size: 1rem; line-height: 1; }
.cbc-pillar strong {
  font-family: var(--font-ui);
  font-size: .78rem;
  font-weight: 700;
  color: var(--bisque-dark);
  letter-spacing: .04em;
}
.cbc-pillar span {
  font-size: .75rem;
  color: rgba(255,228,196,.35);
  font-family: var(--font-ui);
}

/* ═══════════════════════════════════════════════
   ABOUT MWALIMU
═══════════════════════════════════════════════ */
.about-mwalimu {
  background: var(--white);
  border-bottom: 1px solid var(--cream-200);
  padding: var(--section-py) var(--pad-x);
}
.about-mwalimu-inner {
  max-width: var(--max-w);
  margin: 0 auto;
  display: grid;
  grid-template-columns: 240px 1fr;
  gap: clamp(2rem, 5vw, 4rem);
  align-items: start;
}
.am-badge-col { display: flex; flex-direction: column; align-items: center; gap: 1rem; }
.am-avatar {
  width: 110px; height: 110px;
  border-radius: 50%;
  border: 4px solid var(--bisque-dark);
  box-shadow: 0 8px 28px rgba(10,22,40,.2);
  flex-shrink: 0;
  overflow: hidden;
  background: var(--navy-800);
}
.am-avatar img {
  width: 100%; height: 100%;
  object-fit: cover;
  object-position: center top;
  display: block;
}
.am-credentials { display: flex; flex-direction: column; gap: 6px; align-items: center; }
.am-cred-pill {
  background: var(--cream-100);
  border: 1px solid var(--cream-200);
  border-radius: var(--radius-pill);
  padding: .28rem .85rem;
  font-family: var(--font-ui);
  font-size: .76rem;
  font-weight: 600;
  color: var(--navy-700);
  text-align: center;
  white-space: nowrap;
}
.am-content h2 {
  font-size: clamp(1.5rem, 3vw, 2rem);
  margin-bottom: .8rem;
  margin-top: .4rem;
}
.am-content p {
  font-family: var(--font-ui);
  font-size: .95rem;
  line-height: 1.8;
  color: var(--ink-50);
  margin-bottom: .9rem;
}
.am-content p strong { color: var(--navy-800); font-weight: 600; }
.am-content p em { font-style: italic; color: var(--navy-700); }
.am-content a { color: var(--navy-700); }

/* ═══════════════════════════════════════════════
   TOPICS GRID
═══════════════════════════════════════════════ */
.topics-section { padding: var(--section-py) var(--pad-x); }
.topics-section-inner { max-width: var(--max-w); margin: 0 auto; }

/* Toolbar */
.topics-toolbar {
  display: flex;
  align-items: center;
  justify-content: space-between;
  flex-wrap: wrap;
  gap: .75rem;
  margin-bottom: 1.5rem;
  padding: .75rem 1rem;
  background: var(--white);
  border: 1px solid var(--cream-200);
  border-radius: var(--radius-md);
  box-shadow: var(--shadow-xs);
}
.toolbar-filters { display: flex; flex-wrap: wrap; gap: 6px; }
.filter-btn {
  font-family: var(--font-ui);
  font-size: .8rem;
  font-weight: 600;
  padding: .35rem .9rem;
  border-radius: var(--radius-pill);
  border: 1.5px solid var(--cream-200);
  background: var(--cream);
  color: var(--ink-50);
  cursor: pointer;
  transition: var(--transition);
  white-space: nowrap;
}
.filter-btn:hover { border-color: var(--navy-700); color: var(--navy-700); }
.filter-btn.active {
  background: var(--navy-700);
  border-color: var(--navy-700);
  color: var(--bisque-light);
}
.toolbar-sort select {
  font-family: var(--font-ui);
  font-size: .82rem;
  padding: .38rem .8rem;
  border: 1.5px solid var(--cream-200);
  border-radius: var(--radius-pill);
  background: var(--cream);
  color: var(--ink-50);
  cursor: pointer;
  outline: none;
  transition: var(--transition);
}
.toolbar-sort select:hover, .toolbar-sort select:focus { border-color: var(--navy-700); }

.no-results-msg {
  text-align: center;
  padding: 2rem;
  color: var(--ink-30);
  font-family: var(--font-ui);
  font-size: .95rem;
}

.topics-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(290px, 1fr));
  gap: 20px;
}
@media (min-width: 1100px) {
  .topics-grid { grid-template-columns: repeat(3, 1fr); }
}

.topic-card {
  background: var(--white);
  border-radius: var(--radius-lg);
  border: 1px solid var(--cream-200);
  box-shadow: var(--shadow-sm);
  overflow: hidden;
  transition: transform var(--transition), box-shadow var(--transition);
  display: flex;
  flex-direction: column;
}
.topic-card.hidden { display: none; }
/* FIX: hover only applies transform when card is NOT being animated —
   the anim-hidden/visible classes control opacity+transform during scroll,
   and JS removes them before hover can apply, so no conflict. */
.topic-card:hover { transform: translateY(-5px); box-shadow: var(--shadow-md); }

.tc-accent { height: 4px; width: 100%; }
.tc-algebra     .tc-accent { background: var(--navy-700); }
.tc-trig        .tc-accent { background: #7a4a14; }
.tc-statistics  .tc-accent { background: var(--green); }
.tc-calculus    .tc-accent { background: #5b3a8a; }
.tc-diff        .tc-accent { background: #5b3a8a; }
.tc-integration .tc-accent { background: #3a5f8a; }
.tc-vectors     .tc-accent { background: var(--bisque-deep); }
.tc-matrices    .tc-accent { background: #6b3c14; }
.tc-conics      .tc-accent { background: #0e6888; }
.tc-sequences   .tc-accent { background: #1d6e6e; }
.tc-complex     .tc-accent { background: #7a1060; }
.tc-areas       .tc-accent { background: #3a7a30; }
.tc-volumes     .tc-accent { background: #1a5080; }

.tc-inner { padding: 20px 20px 18px; display: flex; flex-direction: column; flex: 1; }
.tc-header { display: flex; align-items: flex-start; gap: 12px; margin-bottom: 12px; }
.tc-icon {
  width: 40px; height: 40px;
  display: flex; align-items: center; justify-content: center;
  background: var(--cream-100);
  border-radius: var(--radius-sm);
  font-size: 1.15rem;
  font-family: var(--font-mono);
  color: var(--navy-700);
  font-weight: 700;
  flex-shrink: 0;
  margin-top: 2px;
}
.tc-header h3 { font-size: 1.05rem; color: var(--navy-800); margin: 0 0 4px; }
.tc-strand-tag {
  font-family: var(--font-ui);
  font-size: .68rem;
  font-weight: 700;
  letter-spacing: .07em;
  text-transform: uppercase;
  color: var(--bisque-deep);
}
.tc-preview {
  display: flex; align-items: center; gap: 7px;
  background: var(--cream-100);
  border: 1px solid var(--cream-200);
  border-radius: var(--radius-sm);
  padding: 9px 12px;
  margin-bottom: 12px;
  flex-wrap: wrap;
}
.tc-preview code {
  font-family: var(--font-mono);
  font-size: .82rem;
  color: var(--navy-800);
  background: none;
}
.tc-arrow { color: var(--ink-30); font-size: .85rem; font-weight: 700; }
.tc-ans { color: var(--green) !important; font-weight: 700 !important; }
.tc-list { flex: 1; display: flex; flex-direction: column; gap: 5px; margin-bottom: 12px; }
.tc-list li {
  font-family: var(--font-ui);
  font-size: .85rem;
  color: var(--ink-50);
  padding-left: 14px;
  position: relative;
  line-height: 1.45;
}
.tc-list li::before {
  content: '·';
  position: absolute; left: 3px;
  color: var(--bisque-deep);
  font-weight: 700;
}
.tc-meta { margin-bottom: 12px; }
.tc-diff {
  font-family: var(--font-ui);
  font-size: .72rem;
  font-weight: 700;
  padding: .2rem .7rem;
  border-radius: var(--radius-pill);
  letter-spacing: .04em;
}
.tc-diff[data-level="1"] { background: var(--green-bg); color: var(--green-dark); }
.tc-diff[data-level="2"] { background: rgba(200,131,42,.1); color: var(--bisque-deep); }
.tc-diff[data-level="3"] { background: rgba(91,58,138,.1); color: #5b3a8a; }
.tc-link {
  display: inline-flex; align-items: center; gap: 4px;
  font-family: var(--font-ui);
  font-size: .84rem;
  font-weight: 700;
  color: var(--navy-700);
  text-decoration: none;
  padding: 6px 0;
  border-bottom: 2px solid transparent;
  transition: var(--transition);
  margin-top: auto;
}
.tc-link span { transition: transform var(--transition); }
.tc-link:hover { color: var(--navy-900); border-bottom-color: var(--navy-700); }
.tc-link:hover span { transform: translateX(4px); }

/* ═══════════════════════════════════════════════
   FEATURED LESSON
═══════════════════════════════════════════════ */
.featured-section {
  background: var(--white);
  padding: var(--section-py) var(--pad-x);
  border-top: 1px solid var(--cream-200);
  border-bottom: 1px solid var(--cream-200);
}
.featured-section-inner { max-width: var(--max-w); margin: 0 auto; }
.lesson-card {
  background: var(--cream-100);
  border: 1px solid var(--cream-200);
  border-radius: var(--radius-xl);
  padding: clamp(1.2rem, 3vw, 2.4rem);
  box-shadow: var(--shadow-sm);
}
.lesson-intro { margin-bottom: 1.5rem; display: flex; flex-wrap: wrap; gap: 1.5rem; align-items: flex-start; }
.lesson-formula-box {
  display: inline-block;
  background: var(--navy-800);
  border-radius: var(--radius-md);
  padding: 14px 24px;
  text-align: center;
  flex-shrink: 0;
}
.lf-label {
  font-family: var(--font-ui);
  font-size: .7rem;
  font-weight: 700;
  letter-spacing: .1em;
  text-transform: uppercase;
  color: rgba(255,228,196,.45);
  margin-bottom: 5px;
}
.lf-eq {
  font-family: var(--font-mono);
  font-size: 1rem;
  font-weight: 600;
  color: var(--bisque);
  margin: 0;
}
.lesson-context {
  font-family: var(--font-ui);
  font-size: .92rem;
  color: var(--ink-50);
  line-height: 1.75;
  max-width: 580px;
  flex: 1;
}
.methods-row {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(270px, 1fr));
  gap: 18px;
  margin-bottom: 22px;
}
.method-block {
  background: var(--white);
  border-radius: var(--radius-md);
  padding: 20px;
  border: 1px solid var(--cream-200);
  box-shadow: var(--shadow-xs);
  transition: var(--transition);
}
.method-block:hover { box-shadow: var(--shadow-md); transform: translateY(-3px); }
.mb-header { display: flex; align-items: center; gap: 10px; margin-bottom: 10px; }
.mb-num {
  font-family: var(--font-mono);
  font-size: .72rem;
  font-weight: 700;
  color: var(--bisque-deep);
  background: rgba(200,131,42,.1);
  padding: 3px 9px;
  border-radius: 20px;
  letter-spacing: .04em;
  white-space: nowrap;
}
.mb-header h4 { font-size: .98rem; color: var(--navy-800); margin: 0; }
.mb-context {
  font-family: var(--font-ui);
  font-size: .83rem;
  color: var(--ink-30);
  line-height: 1.6;
  margin-bottom: 10px;
  font-style: italic;
}
.mb-example {
  font-family: var(--font-mono);
  font-size: .86rem;
  color: var(--navy-700);
  background: var(--cream-100);
  padding: 7px 11px;
  border-radius: var(--radius-sm);
  margin-bottom: 12px;
  font-weight: 600;
}
.mb-steps {
  list-style: decimal;
  padding-left: 20px;
  display: flex;
  flex-direction: column;
  gap: 6px;
  margin-bottom: 14px;
}
.mb-steps li {
  font-family: var(--font-ui);
  font-size: .86rem;
  color: var(--ink-50);
  line-height: 1.55;
}
.mb-steps li strong { color: var(--navy-800); font-weight: 600; }
.mb-answer {
  background: var(--green-bg);
  color: var(--green);
  font-family: var(--font-mono);
  font-weight: 700;
  font-size: .88rem;
  padding: 8px 13px;
  border-radius: var(--radius-sm);
  display: inline-block;
  border: 1px solid rgba(30,110,54,.2);
}
.mb-check {
  font-family: var(--font-ui);
  font-size: .78rem;
  color: var(--green);
  margin-top: 8px;
  font-weight: 500;
}

/* Discriminant box */
.discriminant-box {
  background: var(--navy-800);
  border-radius: var(--radius-lg);
  padding: 1.4rem 1.8rem;
  margin-bottom: 1.4rem;
}
.discriminant-box h5 {
  font-family: var(--font-ui);
  font-size: .82rem;
  font-weight: 700;
  letter-spacing: .08em;
  text-transform: uppercase;
  color: rgba(255,228,196,.5);
  margin-bottom: 1rem;
}
.disc-cases {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(160px, 1fr));
  gap: 12px;
}
.disc-case {
  background: rgba(255,255,255,.04);
  border: 1px solid rgba(255,228,196,.1);
  border-radius: var(--radius-md);
  padding: 12px;
  display: flex;
  flex-direction: column;
  gap: 4px;
}
.disc-case strong { font-family: var(--font-mono); font-size: .95rem; font-weight: 700; }
.disc-case span   { font-family: var(--font-ui); font-size: .82rem; line-height: 1.4; }
.disc-case .dc-eg { font-family: var(--font-mono); font-size: .74rem; opacity: .6; }
.dc-pos strong { color: var(--green); }
.dc-pos span   { color: rgba(255,228,196,.6); }
.dc-zero strong{ color: var(--bisque-dark); }
.dc-zero span  { color: rgba(255,228,196,.6); }
.dc-neg strong { color: #f87171; }
.dc-neg span   { color: rgba(255,228,196,.6); }

.lesson-footer-row {
  display: flex;
  align-items: flex-start;
  justify-content: space-between;
  gap: 20px;
  flex-wrap: wrap;
  padding-top: 18px;
  border-top: 1px solid var(--cream-200);
}
.lf-mistakes h5 {
  font-family: var(--font-ui);
  font-size: .86rem;
  font-weight: 700;
  color: var(--navy-800);
  margin-bottom: 8px;
}
.lf-mistakes ul { display: flex; flex-direction: column; gap: 4px; }
.lf-mistakes li {
  font-family: var(--font-ui);
  font-size: .83rem;
  color: var(--ink-50);
  padding-left: 18px;
  position: relative;
  line-height: 1.5;
}
.lf-mistakes li::before {
  content: "⚠";
  position: absolute; left: 0;
  font-size: .72rem;
  color: #c0392b;
  top: 1px;
}
.btn-lesson-more {
  display: inline-flex;
  align-items: center;
  background: var(--navy-700);
  color: var(--bisque-light);
  font-family: var(--font-ui);
  font-weight: 700;
  font-size: .88rem;
  padding: .7rem 1.5rem;
  border-radius: var(--radius-pill);
  text-decoration: none;
  white-space: nowrap;
  transition: var(--transition);
  flex-shrink: 0;
}
.btn-lesson-more:hover { background: var(--navy-800); color: var(--bisque); transform: translateX(4px); }

/* ═══════════════════════════════════════════════
   EXAMPLES
═══════════════════════════════════════════════ */
.examples-section { padding: var(--section-py) var(--pad-x); }
.examples-section-inner { max-width: var(--max-w); margin: 0 auto; }
.examples-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(220px, 1fr));
  gap: 16px;
}
.eg-card {
  background: var(--white);
  border: 1px solid var(--cream-200);
  border-radius: var(--radius-md);
  padding: 20px;
  box-shadow: var(--shadow-xs);
  transition: var(--transition);
}
.eg-card:hover { box-shadow: var(--shadow-md); transform: translateY(-3px); }
.eg-topic {
  font-family: var(--font-ui);
  font-size: .68rem;
  font-weight: 700;
  letter-spacing: .1em;
  text-transform: uppercase;
  color: var(--bisque-deep);
  margin-bottom: 8px;
}
.eg-problem {
  font-family: var(--font-mono);
  font-size: .88rem;
  color: var(--navy-800);
  margin-bottom: 10px;
  font-weight: 600;
}
.eg-steps {
  background: var(--cream-100);
  border-radius: var(--radius-sm);
  padding: 11px 13px;
  display: flex;
  flex-direction: column;
  gap: 4px;
}
.eg-steps p { font-family: var(--font-mono); font-size: .82rem; color: var(--ink-50); margin: 0; }
.eg-ans { color: var(--green) !important; font-weight: 700 !important; font-size: .9rem !important; }

/* ═══════════════════════════════════════════════
   HOW IT WORKS
═══════════════════════════════════════════════ */
.how-section {
  background: var(--white);
  border-top: 1px solid var(--cream-200);
  border-bottom: 1px solid var(--cream-200);
  padding: var(--section-py) var(--pad-x);
}
.how-section-inner { max-width: var(--max-w); margin: 0 auto; }
.how-steps {
  display: flex;
  flex-direction: column;
  gap: 0;
  max-width: 800px;
  margin: 0 auto;
}
.how-step {
  display: flex;
  gap: 1.4rem;
  padding: 1.5rem 0;
  position: relative;
  align-items: flex-start;
}
.how-step + .how-step { border-top: 1px solid var(--cream-200); }
.how-step-num {
  width: 44px; height: 44px;
  flex-shrink: 0;
  background: var(--navy-700);
  color: var(--bisque-dark);
  font-family: var(--font-display);
  font-size: 1.2rem;
  font-weight: 900;
  display: flex; align-items: center; justify-content: center;
  border-radius: 50%;
  box-shadow: 0 4px 14px rgba(10,22,40,.15);
}
.how-step-body h3 { font-size: 1.05rem; color: var(--navy-800); margin-bottom: .4rem; }
.how-step-body p { font-family: var(--font-ui); font-size: .92rem; color: var(--ink-50); line-height: 1.75; }
.how-step-body a { color: var(--navy-700); font-weight: 600; }

/* ═══════════════════════════════════════════════
   WHY SECTION
═══════════════════════════════════════════════ */
.why-section {
  background: var(--cream-100);
  border-top: 1px solid var(--cream-200);
  border-bottom: 1px solid var(--cream-200);
  padding: var(--section-py) var(--pad-x);
}
.why-section-inner { max-width: var(--max-w); margin: 0 auto; }
.why-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(270px, 1fr));
  gap: 18px;
}
.why-card {
  background: var(--white);
  border: 1px solid var(--cream-200);
  border-radius: var(--radius-md);
  padding: 24px;
  box-shadow: var(--shadow-xs);
  transition: var(--transition);
}
.why-card:hover { transform: translateY(-4px); box-shadow: var(--shadow-md); border-color: var(--bisque-dark); }
.why-icon { font-size: 1.8rem; margin-bottom: 12px; line-height: 1; }
.why-card h3 { font-size: 1rem; color: var(--navy-800); margin-bottom: 7px; }
.why-card p { font-family: var(--font-ui); font-size: .88rem; color: var(--ink-50); line-height: 1.7; }

/* ═══════════════════════════════════════════════
   FAQ
═══════════════════════════════════════════════ */
.faq-section { padding: var(--section-py) var(--pad-x); }
.faq-section-inner { max-width: 820px; margin: 0 auto; }
.faq-list { display: flex; flex-direction: column; gap: 0; }
.faq-item { border-bottom: 1px solid var(--cream-200); }
.faq-item:first-child { border-top: 1px solid var(--cream-200); }
.faq-q {
  width: 100%;
  background: none;
  border: none;
  cursor: pointer;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 1rem;
  padding: 1.1rem 0;
  font-family: var(--font-display);
  font-size: 1rem;
  font-weight: 700;
  color: var(--navy-800);
  text-align: left;
  transition: color var(--transition);
}
.faq-q:hover { color: var(--navy-600); }
.faq-chevron { flex-shrink: 0; transition: transform var(--transition); }
.faq-q[aria-expanded="true"] .faq-chevron { transform: rotate(180deg); }
.faq-a { padding: 0 0 1.1rem; animation: fadeUp .2s ease; }
.faq-a p { font-family: var(--font-ui); font-size: .92rem; color: var(--ink-50); line-height: 1.8; }
.faq-a a { color: var(--navy-700); font-weight: 600; }
.faq-a strong { color: var(--navy-800); font-weight: 600; }

/* ═══════════════════════════════════════════════
   CTA BAND
═══════════════════════════════════════════════ */
.cta-band {
  background: linear-gradient(155deg, var(--navy-950) 0%, var(--navy-800) 55%, var(--navy-700) 100%);
  padding: clamp(3rem, 8vw, 5rem) var(--pad-x);
  text-align: center;
  position: relative;
  overflow: hidden;
  border-top: 3px solid var(--bisque-deep);
}
.cta-band::before {
  content: '';
  position: absolute; inset: 0;
  background: radial-gradient(ellipse 60% 60% at 50% 110%, rgba(200,131,42,.15) 0%, transparent 70%);
  pointer-events: none;
}
.cta-band-inner { position: relative; z-index: 1; max-width: 700px; margin: 0 auto; }
.cta-band h2 {
  font-family: var(--font-display);
  font-size: clamp(1.8rem, 4vw, 2.6rem);
  color: var(--bisque-light);
  margin-bottom: 12px;
}
.cta-band p {
  font-family: var(--font-serif);
  font-size: 1rem;
  color: rgba(255,228,196,.55);
  line-height: 1.75;
  margin-bottom: 28px;
}
.cta-btns { display: flex; gap: 12px; justify-content: center; flex-wrap: wrap; }
.btn-cta-primary {
  background: var(--bisque);
  color: var(--navy-900);
  font-family: var(--font-ui);
  font-weight: 700;
  font-size: 1rem;
  padding: .9rem 2.2rem;
  border-radius: var(--radius-pill);
  text-decoration: none;
  border: 2px solid var(--bisque-dark);
  transition: var(--transition);
  box-shadow: 0 4px 20px rgba(200,131,42,.25);
}
.btn-cta-primary:hover { background: var(--bisque-light); transform: translateY(-3px); box-shadow: 0 8px 28px rgba(200,131,42,.35); }
.btn-cta-secondary {
  background: transparent;
  color: rgba(255,228,196,.75);
  font-family: var(--font-ui);
  font-weight: 600;
  font-size: 1rem;
  padding: .9rem 2.2rem;
  border-radius: var(--radius-pill);
  border: 2px solid rgba(255,228,196,.3);
  text-decoration: none;
  transition: var(--transition);
}
.btn-cta-secondary:hover { background: rgba(255,228,196,.1); border-color: rgba(255,228,196,.6); color: var(--bisque); transform: translateY(-3px); }

/* ═══════════════════════════════════════════════
   FOOTER
═══════════════════════════════════════════════ */
.site-footer {
  background: var(--navy-950);
  border-top: 3px solid var(--bisque-deep);
  padding: clamp(2.5rem, 5vw, 3.5rem) var(--pad-x) 0;
  margin-top: auto;
}
.footer-inner {
  max-width: var(--max-w);
  margin: 0 auto;
  display: grid;
  /* FIX: 4 explicit columns — .footer-nav has display:contents so its 3
     children (.fn-col) become direct grid children alongside .footer-brand */
  grid-template-columns: 1.3fr 1fr 0.9fr 0.9fr;
  gap: clamp(1.5rem, 4vw, 3rem);
  padding-bottom: clamp(2rem, 4vw, 3rem);
  border-bottom: 1px solid rgba(255,228,196,.08);
}
.footer-logo {
  font-family: var(--font-display);
  font-size: 1.2rem;
  font-weight: 700;
  color: var(--bisque-light);
  text-decoration: none;
  display: block;
  margin-bottom: 8px;
}
.footer-logo span { color: var(--bisque-dark); }
.footer-brand p { font-family: var(--font-ui); font-size: .85rem; color: rgba(255,228,196,.35); line-height: 1.65; }
.footer-cbc-note { font-size: .76rem !important; color: rgba(255,228,196,.25) !important; margin-top: 6px; font-style: italic; }
.footer-contact-line { margin-top: 12px !important; font-size: .8rem !important; }
.footer-contact-line a { color: var(--bisque-dark) !important; text-decoration: none; font-weight: 500; transition: color var(--transition); }
.footer-contact-line a:hover { color: var(--bisque) !important; }
/* FIX: display:contents makes .footer-nav transparent to the grid,
   so its children (.fn-col) slot directly into grid columns.
   This works in all modern browsers; IE11 is not supported. */
.footer-nav { display: contents; }
.fn-col h4 {
  font-family: var(--font-ui);
  font-size: .7rem;
  font-weight: 700;
  letter-spacing: .1em;
  text-transform: uppercase;
  color: rgba(255,228,196,.4);
  margin-bottom: 12px;
}
.fn-col ul { display: flex; flex-direction: column; gap: 7px; }
.fn-col a { font-family: var(--font-ui); font-size: .85rem; color: rgba(255,228,196,.4); text-decoration: none; font-weight: 400; transition: color var(--transition); }
.fn-col a:hover { color: var(--bisque-light); }
.footer-bottom {
  max-width: var(--max-w);
  margin: 0 auto;
  padding: 18px 0 24px;
  display: flex;
  flex-wrap: wrap;
  justify-content: space-between;
  gap: 8px;
}
.footer-bottom p { font-family: var(--font-ui); font-size: .78rem; color: rgba(255,228,196,.2); line-height: 1.6; }
.footer-mission { font-style: italic; }

/* ═══════════════════════════════════════════════
   ANIMATIONS
═══════════════════════════════════════════════ */
@keyframes fadeUp {
  from { opacity: 0; transform: translateY(14px); }
  to   { opacity: 1; transform: translateY(0); }
}

/* ═══════════════════════════════════════════════
   RESPONSIVE
═══════════════════════════════════════════════ */

/* Tablet */
@media (max-width: 1024px) {
  .hero { grid-template-columns: 1fr; }
  .hero-formula-card { display: none; }
  .footer-inner { grid-template-columns: 1fr 1fr; }
  .about-mwalimu-inner { grid-template-columns: 180px 1fr; }
}

/* Mobile nav */
@media (max-width: 820px) {
  .nav-mobile-bar { display: flex; }

  /* FIX: nav-inner must be overflow:visible so search results
     aren't clipped; but the nav itself can scroll if needed */
  .main-nav  { overflow: visible; }
  .nav-inner { overflow: visible; }

  /* FIX: search results use fixed positioning on mobile so they
     escape any stacking / overflow context */
  .search-results {
    position: fixed;
    top: auto;
    left: 1rem;
    right: 1rem;
    /* top is set dynamically if needed; on mobile it naturally
       appears below the sticky nav */
    z-index: 700;
  }

  /* FIX: search bar needs explicit background so it covers content beneath */
  .nav-search-bar {
    background: var(--navy-900);
    padding: .5rem 0 .6rem;
    z-index: 510;
  }

  .nav-list {
    display: none;
    flex-direction: column;
    width: 100%;
    padding: .5rem 0 1rem;
    border-top: 1px solid rgba(255,228,196,.08);
    gap: 0;
  }
  .nav-list.open { display: flex; }

  .nav-list > li > a {
    padding: .7rem .5rem;
    justify-content: space-between;
    font-size: .92rem;
  }
  .nav-list > li > a::after { display: none; }

  /* Mobile dropdown — hidden by default, shown via .open class */
  .nav-has-dropdown:hover .nav-dropdown,
  .nav-has-dropdown:focus-within .nav-dropdown { display: none; }
  .nav-has-dropdown.open .nav-dropdown { display: block; }
  .nav-has-dropdown.open .nav-chevron  { transform: rotate(180deg); }

  .nav-dropdown {
    position: static;
    box-shadow: none;
    border: none;
    background: rgba(255,228,196,.04);
    border-radius: var(--radius-sm);
    padding: .25rem .5rem;
    margin: 0 0 .25rem .5rem;
    animation: none;
  }
  .nav-dropdown li a { font-size: .88rem; padding: .5rem .8rem; }
}

@media (max-width: 768px) {
  .hero { padding: clamp(2.5rem, 6vw, 3.5rem) var(--pad-x); }
  .hero h1 { font-size: 2.2rem; }
  .hero-cta-row { flex-direction: column; align-items: flex-start; }
  .about-mwalimu-inner { grid-template-columns: 1fr; }
  .am-badge-col { flex-direction: row; align-items: center; flex-wrap: wrap; }
  .cbc-band-title { display: none; }
  .methods-row { grid-template-columns: 1fr; }
  .lesson-footer-row { flex-direction: column; }
  .cta-btns { flex-direction: column; align-items: center; }
  .btn-cta-primary, .btn-cta-secondary { width: 100%; max-width: 320px; text-align: center; justify-content: center; }
  .footer-inner { grid-template-columns: 1fr; }
  .footer-bottom { flex-direction: column; text-align: center; }
  .disc-cases { grid-template-columns: 1fr; }
}

@media (max-width: 480px) {
  .site-header { padding: 18px var(--pad-x); }
  .header-inner { flex-direction: column; align-items: flex-start; gap: 8px; }
  .welcome-pill { font-size: .74rem; }
  .topics-toolbar { flex-direction: column; align-items: flex-start; }
  .toolbar-sort { width: 100%; }
  .toolbar-sort select { width: 100%; }
  .topics-grid { grid-template-columns: 1fr; }
  .examples-grid { grid-template-columns: 1fr; }
  .why-grid { grid-template-columns: 1fr; }
}

/* ═══════════════════════════════════════════════
   ACCESSIBILITY
═══════════════════════════════════════════════ */
@media (prefers-reduced-motion: reduce) {
  *, *::before, *::after {
    animation-duration: 0.01ms !important;
    transition-duration: 0.01ms !important;
  }
  /* Also prevent entrance animations from leaving elements invisible */
  .anim-hidden { opacity: 1 !important; transform: none !important; }
}

/* ═══════════════════════════════════════════════
   PRINT
═══════════════════════════════════════════════ */
@media print {
  .main-nav, .cta-band, .site-footer, .cbc-band { display: none; }
  body { background: white; }
  .hero { background: #0a1628 !important; }
}
/* ── PWA install banner ── */
#pwa-banner {
  position: fixed;
  bottom: 0; left: 0; right: 0;
  background: var(--navy-900);
  border-top: 2px solid var(--bisque-dark);
  z-index: 2000;
  padding: 12px var(--pad-x);
  animation: slideUp .3s ease;
}
@keyframes slideUp {
  from { transform: translateY(100%); }
  to   { transform: translateY(0); }
}
.pwa-banner-inner {
  max-width: var(--max-w);
  margin: 0 auto;
  display: flex;
  align-items: center;
  gap: 14px;
  flex-wrap: wrap;
}
.pwa-banner-icon {
  border-radius: 10px;
  flex-shrink: 0;
}
.pwa-banner-text {
  flex: 1;
  min-width: 160px;
  display: flex;
  flex-direction: column;
  gap: 2px;
}
.pwa-banner-text strong {
  font-family: var(--font-ui);
  font-size: .92rem;
  font-weight: 700;
  color: var(--bisque-light);
}
.pwa-banner-text span {
  font-family: var(--font-ui);
  font-size: .78rem;
  color: rgba(255,228,196,.45);
}
.pwa-btn-install {
  background: var(--bisque);
  color: var(--navy-900);
  border: none;
  font-family: var(--font-ui);
  font-weight: 700;
  font-size: .88rem;
  padding: .55rem 1.4rem;
  border-radius: var(--radius-pill);
  cursor: pointer;
  transition: var(--transition);
  white-space: nowrap;
}
.pwa-btn-install:hover { background: var(--bisque-light); }
.pwa-btn-dismiss {
  background: none;
  border: none;
  color: rgba(255,228,196,.35);
  font-size: 1rem;
  cursor: pointer;
  padding: 4px 8px;
  border-radius: 4px;
  flex-shrink: 0;
  transition: color var(--transition);
}
.pwa-btn-dismiss:hover { color: var(--bisque); }
/* ── iOS install tooltip ── */
#ios-banner {
  position: fixed;
  bottom: 0; left: 0; right: 0;
  background: var(--navy-900);
  border-top: 2px solid var(--bisque-dark);
  z-index: 2000;
  padding: 14px var(--pad-x) 20px;
  animation: slideUp .3s ease;
}
.ios-banner-inner {
  max-width: var(--max-w);
  margin: 0 auto;
  position: relative;
}
.ios-banner-title {
  font-family: var(--font-ui);
  font-size: .92rem;
  font-weight: 700;
  color: var(--bisque-light);
  margin-bottom: 6px;
}
.ios-banner-steps {
  font-family: var(--font-ui);
  font-size: .82rem;
  color: rgba(255,228,196,.6);
  line-height: 1.7;
  margin-bottom: 4px;
}
.ios-banner-steps span {
  color: var(--bisque-dark);
  font-weight: 700;
}
.ios-banner-arrow {
  position: absolute;
  bottom: -18px;
  left: 50%;
  transform: translateX(-50%);
  width: 0; height: 0;
  border-left: 10px solid transparent;
  border-right: 10px solid transparent;
  border-top: 10px solid var(--bisque-dark);
}
.ios-btn-dismiss {
  position: absolute;
  top: 0; right: 0;
  background: none;
  border: none;
  color: rgba(255,228,196,.35);
  font-size: 1rem;
  cursor: pointer;
  padding: 4px 8px;
  border-radius: 4px;
  transition: color var(--transition);
}
.ios-btn-dismiss:hover { color: var(--bisque); }