/* ============================================================
   Bac2Chesda — Global Stylesheet
   Theme: Crisp white, warm gold & crimson accents
   Font: Playfair Display (headings) + DM Sans (body)
   ============================================================ */

@import url('https://fonts.googleapis.com/css2?family=Playfair+Display:wght@500;700;900&family=DM+Sans:wght@300;400;500;600&display=swap');

/* ── CSS Variables ── */
:root {
  --white:       #ffffff;
  --off-white:   #faf9f7;
  --cream:       #f5f0e8;
  --gold:        #c9973a;
  --gold-light:  #e8c06a;
  --gold-pale:   #fdf6e3;
  --crimson:     #b91c1c;
  --crimson-soft:#fef2f2;
  --navy:        #1a2340;
  --slate:       #4a5568;
  --muted:       #9ca3af;
  --border:      #e8e2d9;
  --shadow-sm:   0 1px 3px rgba(0,0,0,.07), 0 1px 2px rgba(0,0,0,.05);
  --shadow-md:   0 4px 16px rgba(0,0,0,.08);
  --shadow-lg:   0 12px 40px rgba(0,0,0,.12);
  --shadow-gold: 0 8px 32px rgba(201,151,58,.20);
  --radius-sm:   8px;
  --radius-md:   16px;
  --radius-lg:   24px;
  --radius-xl:   32px;
  --transition:  all .25s cubic-bezier(.4,0,.2,1);
}

/* ── Reset & Base ── */
*, *::before, *::after { box-sizing: border-box; margin: 0; padding: 0; }

html { scroll-behavior: smooth; font-size: 16px; }

body {
  font-family: 'DM Sans', sans-serif;
  background-color: var(--off-white);
  color: var(--navy);
  line-height: 1.65;
  -webkit-font-smoothing: antialiased;
  min-height: 100vh;
  display: flex;
  flex-direction: column;
}

h1, h2, h3, h4 {
  font-family: 'Playfair Display', serif;
  line-height: 1.2;
}

a { color: inherit; text-decoration: none; }
img { max-width: 100%; display: block; }
button { font-family: 'DM Sans', sans-serif; cursor: pointer; border: none; }

/* ── Utility ── */
.container {
  width: 100%;
  max-width: 1200px;
  margin: 0 auto;
  padding: 0 1.5rem;
}

.flex-grow { flex: 1 1 auto; }

/* ── Scrollbar ── */
::-webkit-scrollbar { width: 6px; }
::-webkit-scrollbar-track { background: var(--cream); }
::-webkit-scrollbar-thumb { background: var(--gold-light); border-radius: 99px; }

/* ============================================================
   HEADER / NAV
   ============================================================ */
.site-header {
  background: var(--white);
  border-bottom: 1px solid var(--border);
  position: sticky;
  top: 0;
  z-index: 100;
  box-shadow: var(--shadow-sm);
  transition: var(--transition);
}

.site-header.scrolled {
  box-shadow: 0 4px 24px rgba(0,0,0,.10);
}

.nav-inner {
  display: flex;
  align-items: center;
  justify-content: space-between;
  height: 72px;
}

/* Logo */
.logo {
  display: flex;
  align-items: center;
  gap: .75rem;
  text-decoration: none;
}

.logo-badge {
  width: 42px;
  height: 42px;
  background: linear-gradient(135deg, var(--gold) 0%, var(--crimson) 100%);
  border-radius: var(--radius-sm);
  display: flex;
  align-items: center;
  justify-content: center;
  color: white;
  font-family: 'Playfair Display', serif;
  font-weight: 700;
  font-size: 1.1rem;
  letter-spacing: -.5px;
  flex-shrink: 0;
  box-shadow: var(--shadow-gold);
}

.logo-text {
  font-family: 'Playfair Display', serif;
  font-weight: 700;
  font-size: 1.5rem;
  color: var(--navy);
}

.logo-text span {
  color: var(--gold);
}

/* Nav links */
.nav-links {
  display: flex;
  align-items: center;
  gap: 2rem;
  list-style: none;
}

.nav-links a {
  font-weight: 500;
  font-size: .95rem;
  color: var(--slate);
  position: relative;
  padding-bottom: 3px;
  transition: var(--transition);
}

.nav-links a::after {
  content: '';
  position: absolute;
  bottom: 0;
  left: 0;
  width: 0;
  height: 2px;
  background: var(--gold);
  border-radius: 99px;
  transition: width .3s ease;
}

.nav-links a:hover { color: var(--navy); }
.nav-links a:hover::after,
.nav-links a.active::after { width: 100%; }
.nav-links a.active { color: var(--navy); font-weight: 600; }

/* Donate nav btn */
.nav-donate-btn {
  background: linear-gradient(135deg, var(--gold) 0%, #e8a83a 100%);
  color: white !important;
  padding: .5rem 1.25rem;
  border-radius: 99px;
  font-weight: 600 !important;
  font-size: .9rem !important;
  box-shadow: 0 2px 12px rgba(201,151,58,.35);
  transition: var(--transition) !important;
}

.nav-donate-btn::after { display: none !important; }
.nav-donate-btn:hover {
  transform: translateY(-1px);
  box-shadow: 0 4px 18px rgba(201,151,58,.45) !important;
  color: white !important;
}

/* Hamburger */
.hamburger {
  display: none;
  flex-direction: column;
  gap: 5px;
  background: none;
  padding: 6px;
  border-radius: var(--radius-sm);
  transition: var(--transition);
}

.hamburger span {
  display: block;
  width: 24px;
  height: 2px;
  background: var(--navy);
  border-radius: 99px;
  transition: var(--transition);
}

.hamburger.open span:nth-child(1) { transform: translateY(7px) rotate(45deg); }
.hamburger.open span:nth-child(2) { opacity: 0; }
.hamburger.open span:nth-child(3) { transform: translateY(-7px) rotate(-45deg); }

/* Mobile menu */
.mobile-menu {
  display: none;
  flex-direction: column;
  background: var(--white);
  border-top: 1px solid var(--border);
  padding: 1rem 1.5rem 1.5rem;
  gap: .25rem;
}

.mobile-menu.open { display: flex; }

.mobile-menu a {
  font-weight: 500;
  color: var(--slate);
  padding: .75rem 0;
  border-bottom: 1px solid var(--border);
  transition: var(--transition);
  display: flex;
  align-items: center;
  gap: .5rem;
}

.mobile-menu a:last-child { border-bottom: none; }
.mobile-menu a:hover { color: var(--gold); padding-left: .5rem; }

.mobile-donate-btn {
  margin-top: .75rem;
  background: linear-gradient(135deg, var(--gold) 0%, #e8a83a 100%);
  color: white;
  text-align: center;
  padding: .85rem;
  border-radius: var(--radius-md);
  font-weight: 600;
  box-shadow: var(--shadow-gold);
}

.mobile-donate-btn:hover { color: white !important; }

/* ============================================================
   HERO (index.php)
   ============================================================ */
.hero {
  background: var(--white);
  padding: 5rem 0 4rem;
  position: relative;
  overflow: hidden;
}

.hero::before {
  content: '';
  position: absolute;
  top: -40%;
  right: -15%;
  width: 600px;
  height: 600px;
  background: radial-gradient(circle, rgba(201,151,58,.08) 0%, transparent 70%);
  pointer-events: none;
}

.hero::after {
  content: '';
  position: absolute;
  bottom: -30%;
  left: -10%;
  width: 400px;
  height: 400px;
  background: radial-gradient(circle, rgba(185,28,28,.05) 0%, transparent 70%);
  pointer-events: none;
}

.hero-inner {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 4rem;
  align-items: center;
}

.hero-kicker {
  display: inline-flex;
  align-items: center;
  gap: .5rem;
  background: var(--gold-pale);
  color: var(--gold);
  font-weight: 600;
  font-size: .8rem;
  letter-spacing: .08em;
  text-transform: uppercase;
  padding: .4rem 1rem;
  border-radius: 99px;
  border: 1px solid rgba(201,151,58,.25);
  margin-bottom: 1.25rem;
}

.hero-title {
  font-size: clamp(2.25rem, 4vw, 3.5rem);
  color: var(--navy);
  margin-bottom: 1.25rem;
  line-height: 1.1;
}

.hero-title .accent { color: var(--gold); }

.hero-desc {
  font-size: 1.1rem;
  color: var(--slate);
  margin-bottom: 2rem;
  max-width: 480px;
}

.hero-actions {
  display: flex;
  gap: 1rem;
  flex-wrap: wrap;
}

.hero-visual {
  display: flex;
  justify-content: center;
  align-items: center;
}

.hero-card-grid {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 1rem;
  transform: rotate(-2deg);
}

.hero-mini-card {
  background: var(--white);
  border: 1px solid var(--border);
  border-radius: var(--radius-md);
  padding: 1.25rem;
  box-shadow: var(--shadow-md);
  transition: var(--transition);
}

.hero-mini-card:hover { transform: translateY(-4px); box-shadow: var(--shadow-lg); }

.hero-mini-icon {
  width: 40px;
  height: 40px;
  border-radius: var(--radius-sm);
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 1.2rem;
  margin-bottom: .75rem;
}

.hero-mini-card h4 { font-size: .95rem; margin-bottom: .25rem; }
.hero-mini-card p { font-size: .78rem; color: var(--muted); }

.hero-stat-strip {
  display: flex;
  gap: 2rem;
  margin-top: 2.5rem;
  padding-top: 2rem;
  border-top: 1px solid var(--border);
}

.hero-stat strong {
  display: block;
  font-size: 1.6rem;
  font-family: 'Playfair Display', serif;
  color: var(--navy);
}

.hero-stat span { font-size: .85rem; color: var(--muted); }

/* ============================================================
   BUTTONS
   ============================================================ */
.btn {
  display: inline-flex;
  align-items: center;
  gap: .5rem;
  font-weight: 600;
  font-size: .95rem;
  padding: .75rem 1.75rem;
  border-radius: 99px;
  transition: var(--transition);
  cursor: pointer;
  border: none;
  text-decoration: none;
}

.btn-primary {
  background: linear-gradient(135deg, var(--gold) 0%, #d4a040 100%);
  color: white;
  box-shadow: 0 4px 16px rgba(201,151,58,.35);
}

.btn-primary:hover {
  transform: translateY(-2px);
  box-shadow: 0 8px 24px rgba(201,151,58,.45);
  color: white;
}

.btn-secondary {
  background: var(--white);
  color: var(--navy);
  border: 1.5px solid var(--border);
  box-shadow: var(--shadow-sm);
}

.btn-secondary:hover {
  background: var(--cream);
  transform: translateY(-1px);
  box-shadow: var(--shadow-md);
  color: var(--navy);
}

.btn-outline-gold {
  background: transparent;
  color: var(--gold);
  border: 1.5px solid var(--gold);
}

.btn-outline-gold:hover {
  background: var(--gold);
  color: white;
  transform: translateY(-1px);
}

.btn-sm {
  padding: .5rem 1.1rem;
  font-size: .85rem;
}

/* ============================================================
   FEATURE CARDS / DASHBOARD GRID
   ============================================================ */
.cards-section {
  padding: 4rem 0;
}

.section-header {
  text-align: center;
  margin-bottom: 3rem;
}

.section-kicker {
  display: inline-block;
  font-size: .8rem;
  font-weight: 600;
  letter-spacing: .1em;
  text-transform: uppercase;
  color: var(--gold);
  margin-bottom: .75rem;
}

.section-title {
  font-size: clamp(1.75rem, 3vw, 2.5rem);
  color: var(--navy);
  margin-bottom: .75rem;
}

.section-desc {
  font-size: 1rem;
  color: var(--slate);
  max-width: 520px;
  margin: 0 auto;
}

.feature-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 1.5rem;
}

.feature-card {
  background: var(--white);
  border: 1px solid var(--border);
  border-radius: var(--radius-lg);
  padding: 2rem;
  position: relative;
  overflow: hidden;
  transition: var(--transition);
  display: flex;
  flex-direction: column;
}

.feature-card::before {
  content: '';
  position: absolute;
  top: 0;
  left: 0;
  right: 0;
  height: 3px;
  background: linear-gradient(90deg, var(--gold) 0%, var(--gold-light) 100%);
  transform: scaleX(0);
  transform-origin: left;
  transition: transform .35s ease;
}

.feature-card:hover {
  transform: translateY(-6px);
  box-shadow: var(--shadow-lg);
  border-color: transparent;
}

.feature-card:hover::before { transform: scaleX(1); }

.feature-icon-wrap {
  width: 56px;
  height: 56px;
  border-radius: var(--radius-md);
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 1.6rem;
  margin-bottom: 1.25rem;
  flex-shrink: 0;
}

.feature-card h3 {
  font-size: 1.2rem;
  color: var(--navy);
  margin-bottom: .5rem;
}

.feature-card p {
  font-size: .9rem;
  color: var(--slate);
  flex-grow: 1;
  margin-bottom: 1.5rem;
}

/* Card colour variants */
.card-gold   .feature-icon-wrap { background: var(--gold-pale); }
.card-red    .feature-icon-wrap { background: var(--crimson-soft); }
.card-blue   .feature-icon-wrap { background: #eff6ff; }
.card-green  .feature-icon-wrap { background: #f0fdf4; }
.card-purple .feature-icon-wrap { background: #faf5ff; }

/* ============================================================
   BOOK LIBRARY PAGE
   ============================================================ */
.page-hero {
  background: var(--white);
  padding: 3.5rem 0 2.5rem;
  border-bottom: 1px solid var(--border);
  text-align: center;
}

.page-hero-title {
  font-size: clamp(1.75rem, 3vw, 2.75rem);
  color: var(--navy);
  margin-bottom: .5rem;
}

.page-hero-desc {
  font-size: 1rem;
  color: var(--slate);
  max-width: 480px;
  margin: 0 auto;
}

.books-section {
  padding: 3rem 0 5rem;
}

.search-bar-wrap {
  max-width: 480px;
  margin: 0 auto 2.5rem;
  position: relative;
}

.search-bar-wrap input {
  width: 100%;
  padding: .85rem 1rem .85rem 3rem;
  border: 1.5px solid var(--border);
  border-radius: 99px;
  font-family: 'DM Sans', sans-serif;
  font-size: .95rem;
  background: var(--white);
  color: var(--navy);
  outline: none;
  transition: var(--transition);
  box-shadow: var(--shadow-sm);
}

.search-bar-wrap input:focus {
  border-color: var(--gold);
  box-shadow: 0 0 0 3px rgba(201,151,58,.15);
}

.search-bar-wrap .search-icon {
  position: absolute;
  left: 1rem;
  top: 50%;
  transform: translateY(-50%);
  color: var(--muted);
  font-size: 1rem;
  pointer-events: none;
}

.books-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(260px, 1fr));
  gap: 1.25rem;
}

.book-card {
  background: var(--white);
  border: 1px solid var(--border);
  border-radius: var(--radius-md);
  padding: 1.25rem 1.5rem;
  display: flex;
  align-items: center;
  gap: 1rem;
  text-decoration: none;
  transition: var(--transition);
  position: relative;
  overflow: hidden;
}

.book-card::after {
  content: '↓';
  position: absolute;
  right: 1.25rem;
  top: 50%;
  transform: translateY(-50%) translateX(20px);
  color: var(--gold);
  font-size: 1rem;
  font-weight: 700;
  opacity: 0;
  transition: var(--transition);
}

.book-card:hover {
  border-color: var(--gold);
  box-shadow: var(--shadow-gold);
  transform: translateY(-3px);
}

.book-card:hover::after {
  opacity: 1;
  transform: translateY(-50%) translateX(0);
}

.book-icon {
  width: 48px;
  height: 48px;
  border-radius: var(--radius-sm);
  background: var(--gold-pale);
  display: flex;
  align-items: center;
  justify-content: center;
  color: var(--gold);
  font-size: 1.3rem;
  flex-shrink: 0;
}

.book-card h3 {
  font-size: .95rem;
  color: var(--navy);
  font-family: 'DM Sans', sans-serif;
  font-weight: 500;
  line-height: 1.4;
}

.no-books {
  grid-column: 1/-1;
  text-align: center;
  padding: 4rem 0;
  color: var(--muted);
  font-size: 1rem;
}

/* ============================================================
   PDF VIEWER PAGE
   ============================================================ */
.pdf-section {
  padding: 2.5rem 0 4rem;
}

.pdf-year-btns {
  display: flex;
  flex-wrap: wrap;
  gap: .75rem;
  margin-bottom: 1.75rem;
  justify-content: center;
}

.pdf-year-btn {
  background: var(--white);
  border: 1.5px solid var(--border);
  color: var(--slate);
  padding: .55rem 1.25rem;
  border-radius: 99px;
  font-weight: 600;
  font-size: .9rem;
  transition: var(--transition);
  cursor: pointer;
  font-family: 'DM Sans', sans-serif;
}

.pdf-year-btn:hover,
.pdf-year-btn.active {
  background: var(--gold);
  border-color: var(--gold);
  color: white;
  box-shadow: 0 2px 10px rgba(201,151,58,.35);
}

.pdf-viewer-frame {
  width: 100%;
  height: 75vh;
  min-height: 480px;
  border: none;
  border-radius: var(--radius-lg);
  background: var(--cream);
  box-shadow: var(--shadow-md);
}

.pdf-placeholder {
  width: 100%;
  height: 75vh;
  min-height: 480px;
  background: var(--cream);
  border-radius: var(--radius-lg);
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  gap: .75rem;
  color: var(--muted);
  font-size: 1rem;
  border: 2px dashed var(--border);
}

/* ============================================================
   BAC2 CALCULATOR
   ============================================================ */
.calc-section {
  padding: 3rem 0 5rem;
}

.calc-card {
  background: var(--white);
  border: 1px solid var(--border);
  border-radius: var(--radius-xl);
  padding: 2.5rem;
  max-width: 680px;
  margin: 0 auto;
  box-shadow: var(--shadow-md);
}

.calc-card h2 {
  font-size: 1.6rem;
  color: var(--navy);
  margin-bottom: .25rem;
}

.calc-card > p {
  color: var(--slate);
  font-size: .95rem;
  margin-bottom: 2rem;
}

.subject-rows {
  display: flex;
  flex-direction: column;
  gap: .85rem;
  margin-bottom: 2rem;
}

.subject-row {
  display: grid;
  grid-template-columns: 1.5fr .5fr 1fr;
  gap: .75rem;
  align-items: center;
}

.subject-label {
  font-size: .9rem;
  font-weight: 500;
  color: var(--slate);
}

.subject-coeff {
  font-size: .85rem;
  color: var(--muted);
  text-align: center;
  background: var(--cream);
  padding: .4rem .6rem;
  border-radius: var(--radius-sm);
  font-weight: 600;
}

.grade-input {
  padding: .6rem .9rem;
  border: 1.5px solid var(--border);
  border-radius: var(--radius-sm);
  font-family: 'DM Sans', sans-serif;
  font-size: .95rem;
  color: var(--navy);
  background: var(--white);
  outline: none;
  transition: var(--transition);
  width: 100%;
  text-align: center;
}

.grade-input:focus {
  border-color: var(--gold);
  box-shadow: 0 0 0 3px rgba(201,151,58,.15);
}

.calc-divider {
  height: 1px;
  background: var(--border);
  margin: 1.5rem 0;
}

.result-box {
  background: var(--gold-pale);
  border: 1.5px solid rgba(201,151,58,.3);
  border-radius: var(--radius-md);
  padding: 1.5rem 2rem;
  text-align: center;
  margin-bottom: 1.5rem;
  display: none;
}

.result-box.visible { display: block; }

.result-score {
  font-family: 'Playfair Display', serif;
  font-size: 3rem;
  color: var(--gold);
  line-height: 1;
  margin-bottom: .25rem;
}

.result-label {
  font-size: .85rem;
  color: var(--slate);
  font-weight: 500;
}

.result-grade {
  display: inline-block;
  margin-top: .75rem;
  font-size: 1rem;
  font-weight: 700;
  padding: .3rem 1rem;
  border-radius: 99px;
}

.grade-a  { background: #dcfce7; color: #166534; }
.grade-b  { background: #dbeafe; color: #1e40af; }
.grade-c  { background: var(--gold-pale); color: var(--gold); }
.grade-d  { background: #fff7ed; color: #c2410c; }
.grade-e  { background: #fef2f2; color: var(--crimson); }

.calc-btn-row {
  display: flex;
  gap: 1rem;
}

/* ============================================================
   DONATE PAGE
   ============================================================ */
.donate-section {
  padding: 4rem 0 6rem;
  display: flex;
  align-items: center;
  justify-content: center;
  flex: 1;
}

.donate-card {
  background: var(--white);
  border: 1px solid var(--border);
  border-radius: var(--radius-xl);
  padding: 3rem 2.5rem;
  max-width: 520px;
  width: 100%;
  text-align: center;
  box-shadow: var(--shadow-lg);
}

.donate-card .heart-icon {
  font-size: 3rem;
  margin-bottom: 1rem;
  display: block;
  animation: pulse 2s infinite;
}

@keyframes pulse {
  0%, 100% { transform: scale(1); }
  50% { transform: scale(1.1); }
}

.donate-card h2 {
  font-size: 1.8rem;
  color: var(--navy);
  margin-bottom: .75rem;
}

.donate-card p {
  color: var(--slate);
  font-size: .95rem;
  line-height: 1.75;
  margin-bottom: 2rem;
}

.qr-container {
  background: var(--cream);
  border-radius: var(--radius-lg);
  padding: 1.5rem;
  display: inline-block;
  border: 1px solid var(--border);
  box-shadow: var(--shadow-sm);
}

.qr-container img {
  max-width: 240px;
  border-radius: var(--radius-sm);
}

.donate-badge {
  display: inline-flex;
  align-items: center;
  gap: .4rem;
  background: var(--gold-pale);
  color: var(--gold);
  font-size: .8rem;
  font-weight: 600;
  padding: .4rem 1rem;
  border-radius: 99px;
  border: 1px solid rgba(201,151,58,.25);
  margin-bottom: 1.5rem;
}

/* ============================================================
   FOOTER
   ============================================================ */
.site-footer {
  background: var(--navy);
  color: rgba(255,255,255,.75);
  padding: 3rem 0 2rem;
  margin-top: auto;
}

.footer-inner {
  display: grid;
  grid-template-columns: 2fr 1fr 1fr;
  gap: 3rem;
  padding-bottom: 2.5rem;
  border-bottom: 1px solid rgba(255,255,255,.1);
  margin-bottom: 2rem;
}

.footer-brand .logo-text { color: white; }
.footer-brand .logo-badge { box-shadow: none; }

.footer-brand p {
  font-size: .9rem;
  line-height: 1.7;
  margin-top: 1rem;
  max-width: 280px;
}

.footer-col h4 {
  font-family: 'DM Sans', sans-serif;
  font-weight: 600;
  font-size: .85rem;
  letter-spacing: .06em;
  text-transform: uppercase;
  color: rgba(255,255,255,.5);
  margin-bottom: 1rem;
}

.footer-col ul { list-style: none; display: flex; flex-direction: column; gap: .6rem; }

.footer-col ul a {
  font-size: .9rem;
  color: rgba(255,255,255,.65);
  transition: var(--transition);
}

.footer-col ul a:hover { color: var(--gold-light); padding-left: 4px; }

.footer-social {
  display: flex;
  gap: .75rem;
  margin-top: 1.25rem;
}

.social-btn {
  width: 38px;
  height: 38px;
  border-radius: var(--radius-sm);
  background: rgba(255,255,255,.08);
  display: flex;
  align-items: center;
  justify-content: center;
  color: rgba(255,255,255,.7);
  font-size: 1rem;
  transition: var(--transition);
}

.social-btn:hover {
  background: var(--gold);
  color: white;
  transform: translateY(-2px);
}

.footer-bottom {
  display: flex;
  justify-content: space-between;
  align-items: center;
  flex-wrap: wrap;
  gap: 1rem;
}

.footer-bottom p { font-size: .85rem; }

.footer-bottom-links {
  display: flex;
  gap: 1.5rem;
}

.footer-bottom-links a {
  font-size: .8rem;
  color: rgba(255,255,255,.45);
  transition: var(--transition);
}

.footer-bottom-links a:hover { color: var(--gold-light); }

/* ============================================================
   ANIMATIONS (entrance)
   ============================================================ */
[data-anim] {
  opacity: 0;
  transform: translateY(24px);
  transition: opacity .55s ease, transform .55s ease;
}

[data-anim].visible {
  opacity: 1;
  transform: translateY(0);
}

[data-anim-delay="1"] { transition-delay: .1s; }
[data-anim-delay="2"] { transition-delay: .2s; }
[data-anim-delay="3"] { transition-delay: .3s; }
[data-anim-delay="4"] { transition-delay: .4s; }
[data-anim-delay="5"] { transition-delay: .5s; }

/* ============================================================
   RESPONSIVE
   ============================================================ */
@media (max-width: 1024px) {
  .feature-grid { grid-template-columns: repeat(2, 1fr); }
  .footer-inner { grid-template-columns: 1fr 1fr; }
  .footer-brand { grid-column: 1/-1; }
  .hero-inner { gap: 2.5rem; }
}

@media (max-width: 768px) {
  .nav-links, .nav-links { display: none; }
  .hamburger { display: flex; }
  .hero { padding: 3rem 0 2.5rem; }
  .hero-inner { grid-template-columns: 1fr; }
  .hero-visual { display: none; }
  .feature-grid { grid-template-columns: 1fr; }
  .hero-stat-strip { gap: 1.25rem; }
  .footer-inner { grid-template-columns: 1fr; gap: 2rem; }
  .footer-bottom { flex-direction: column; text-align: center; }
  .calc-card { padding: 1.75rem 1.25rem; }
  .subject-row { grid-template-columns: 1fr; }
  .subject-coeff { text-align: left; }
  .calc-btn-row { flex-direction: column; }
  .books-grid { grid-template-columns: 1fr; }
  .pdf-year-btns { justify-content: flex-start; }
  .donate-card { padding: 2rem 1.5rem; }
}

@media (max-width: 480px) {
  .hero-title { font-size: 2rem; }
  .logo-text { font-size: 1.25rem; }
  .hero-actions { flex-direction: column; }
  .hero-actions .btn { justify-content: center; }
}

/* ============================================================
   TOAST NOTIFICATION
   ============================================================ */
.toast {
  position: fixed;
  bottom: 2rem;
  right: 2rem;
  background: var(--navy);
  color: white;
  padding: .85rem 1.5rem;
  border-radius: var(--radius-md);
  font-size: .9rem;
  font-weight: 500;
  box-shadow: var(--shadow-lg);
  z-index: 9999;
  transform: translateY(20px);
  opacity: 0;
  transition: var(--transition);
  display: flex;
  align-items: center;
  gap: .5rem;
}

.toast.show { transform: translateY(0); opacity: 1; }
.toast.success { border-left: 4px solid #22c55e; }
.toast.error   { border-left: 4px solid var(--crimson); }
.toast.info    { border-left: 4px solid var(--gold); }