/* =============================================
   BioByte — assets/css/style.css
   All styles extracted from index.html.
   Do not edit inline; maintain here only.
   ============================================= */

/* =============================================
   DESIGN TOKENS
   ============================================= */
:root {
  --clr-void:        #07110A;   /* deep background */
  --clr-forest:      #0E2016;   /* section bg */
  --clr-panel:       #152B1E;   /* card/panel bg */
  --clr-border:      #1E4030;   /* subtle borders */
  --clr-emerald:     #10B981;   /* primary accent */
  --clr-emerald-dim: #059669;   /* hover / pressed */
  --clr-mint:        #D1FAE5;   /* light tint */
  --clr-text:        #F0FDF4;   /* primary text on dark */
  --clr-muted:       #6ee7b7;   /* secondary text */
  --clr-subdued:     #4B7A63;   /* placeholder/meta */
  --clr-white:       #FFFFFF;

  --radius-sm: 8px;
  --radius-md: 14px;
  --radius-lg: 22px;
  --radius-pill: 9999px;

  --shadow-card: 0 4px 32px rgba(0,0,0,0.45);
  --shadow-glow: 0 0 40px rgba(16,185,129,0.18);

  --font-display: 'Playfair Display', Georgia, serif;
  --font-body:    'Inter', system-ui, sans-serif;

  --transition: 0.25s cubic-bezier(0.4,0,0.2,1);

  /* aliases used by login / signup / teacher-login css */
  --text-muted: var(--clr-muted);
  --accent:     var(--clr-mint);
}

/* =============================================
   RESET & BASE
   ============================================= */
*, *::before, *::after { box-sizing: border-box; margin: 0; padding: 0; }

html { scroll-behavior: smooth; }

body {
  font-family: var(--font-body);
  background: var(--clr-void);
  color: var(--clr-text);
  line-height: 1.6;
  -webkit-font-smoothing: antialiased;
  overflow-x: hidden;
}

img { display: block; max-width: 100%; }

a { color: inherit; text-decoration: none; }

/* =============================================
   UTILITY CLASSES
   ============================================= */
.container {
  width: 100%;
  max-width: 1200px;
  margin: 0 auto;
  padding: 0 24px;
}

.sr-only {
  position: absolute; width: 1px; height: 1px;
  overflow: hidden; clip: rect(0,0,0,0); white-space: nowrap;
}

/* =============================================
   NAVBAR
   ============================================= */
.navbar {
  position: fixed;
  top: 0; left: 0; right: 0;
  z-index: 100;
  padding: 18px 0;
  background: transparent;
  transition: background var(--transition), backdrop-filter var(--transition), border-color var(--transition);
  border-bottom: 1px solid transparent;
}

.navbar.scrolled {
  background: rgba(7, 17, 10, 0.85);
  backdrop-filter: blur(18px);
  -webkit-backdrop-filter: blur(18px);
  border-color: var(--clr-border);
}

.navbar__inner {
  display: flex;
  align-items: center;
  justify-content: space-between;
}

/* Logo */
.navbar__logo {
  display: flex;
  align-items: center;
  gap: 10px;
  font-family: var(--font-display);
  font-size: 1.5rem;
  font-weight: 700;
  color: var(--clr-text);
  letter-spacing: -0.02em;
}

.navbar__logo-icon {
  width: 36px; height: 36px;
  background: var(--clr-emerald);
  border-radius: 10px;
  display: flex; align-items: center; justify-content: center;
  font-size: 1.1rem;
  flex-shrink: 0;
}

.navbar__logo span { color: var(--clr-emerald); }

/* Nav links */
.navbar__actions {
  display: flex;
  align-items: center;
  gap: 12px;
}

.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 8px;
  font-family: var(--font-body);
  font-size: 0.875rem;
  font-weight: 500;
  border-radius: var(--radius-pill);
  padding: 10px 22px;
  cursor: pointer;
  transition: all var(--transition);
  border: 1.5px solid transparent;
  white-space: nowrap;
  line-height: 1;
}

.btn--ghost {
  background: transparent;
  border-color: var(--clr-border);
  color: var(--clr-muted);
}
.btn--ghost:hover {
  border-color: var(--clr-emerald);
  color: var(--clr-emerald);
  background: rgba(16,185,129,0.07);
}

.btn--primary {
  background: var(--clr-emerald);
  border-color: var(--clr-emerald);
  color: var(--clr-void);
  font-weight: 600;
}
.btn--primary:hover {
  background: var(--clr-emerald-dim);
  border-color: var(--clr-emerald-dim);
  transform: translateY(-1px);
  box-shadow: 0 6px 20px rgba(16,185,129,0.35);
}
.btn--primary:active { transform: translateY(0); }

.btn--outline {
  background: transparent;
  border-color: var(--clr-emerald);
  color: var(--clr-emerald);
}
.btn--outline:hover {
  background: rgba(16,185,129,0.1);
}

.btn--lg {
  font-size: 1rem;
  padding: 14px 32px;
  border-radius: var(--radius-pill);
}

/* Mobile menu toggle */
.navbar__menu-toggle {
  display: none;
  background: transparent;
  border: 1.5px solid var(--clr-border);
  border-radius: var(--radius-sm);
  padding: 8px 10px;
  cursor: pointer;
  color: var(--clr-muted);
  font-size: 1.1rem;
  transition: all var(--transition);
}
.navbar__menu-toggle:hover { border-color: var(--clr-emerald); color: var(--clr-emerald); }

/* =============================================
   HERO SECTION
   ============================================= */
.hero {
  position: relative;
  min-height: 100vh;
  display: flex;
  align-items: center;
  overflow: hidden;
  padding: 120px 0 80px;
}

/* DNA helix canvas background */
#hero-canvas {
  position: absolute;
  inset: 0;
  width: 100%; height: 100%;
  opacity: 0.45;
  pointer-events: none;
}

/* Radial glow */
.hero::before {
  content: '';
  position: absolute;
  top: -10%; right: -5%;
  width: 65vw; height: 65vw;
  background: radial-gradient(circle, rgba(16,185,129,0.14) 0%, transparent 65%);
  pointer-events: none;
}

.hero__content {
  position: relative;
  z-index: 2;
  max-width: 700px;
}

.hero__eyebrow {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  font-size: 0.8rem;
  font-weight: 600;
  letter-spacing: 0.12em;
  text-transform: uppercase;
  color: var(--clr-emerald);
  background: rgba(16,185,129,0.1);
  border: 1px solid rgba(16,185,129,0.25);
  border-radius: var(--radius-pill);
  padding: 6px 16px;
  margin-bottom: 28px;
}

.hero__eyebrow-dot {
  width: 6px; height: 6px;
  background: var(--clr-emerald);
  border-radius: 50%;
  animation: pulse 2s ease-in-out infinite;
}

@keyframes pulse {
  0%, 100% { opacity: 1; transform: scale(1); }
  50% { opacity: 0.5; transform: scale(0.8); }
}

.hero__heading {
  font-family: var(--font-display);
  font-size: clamp(2.8rem, 6vw, 5rem);
  font-weight: 700;
  line-height: 1.1;
  letter-spacing: -0.02em;
  color: var(--clr-white);
  margin-bottom: 24px;
}

.hero__heading em {
  font-style: normal;
  color: var(--clr-emerald);
  position: relative;
  display: inline-block;
}

/* Underline accent on "Biology" */
.hero__heading em::after {
  content: '';
  position: absolute;
  bottom: 2px; left: 0; right: 0;
  height: 3px;
  background: linear-gradient(90deg, var(--clr-emerald), transparent);
  border-radius: 2px;
  transform: scaleX(0);
  transform-origin: left;
  animation: underline-in 0.8s 0.6s ease forwards;
}
@keyframes underline-in {
  to { transform: scaleX(1); }
}

.hero__subtitle {
  font-size: 1.15rem;
  color: var(--clr-muted);
  max-width: 520px;
  margin-bottom: 40px;
  line-height: 1.75;
  font-weight: 300;
}

.hero__cta {
  display: flex;
  align-items: center;
  gap: 16px;
  flex-wrap: wrap;
}

.hero__stats {
  display: flex;
  align-items: center;
  gap: 32px;
  margin-top: 64px;
  padding-top: 40px;
  border-top: 1px solid var(--clr-border);
  flex-wrap: wrap;
}

.hero__stat-item {
  display: flex;
  flex-direction: column;
}

.hero__stat-num {
  font-family: var(--font-display);
  font-size: 2rem;
  font-weight: 700;
  color: var(--clr-white);
  line-height: 1;
}

.hero__stat-label {
  font-size: 0.8rem;
  color: var(--clr-subdued);
  margin-top: 4px;
  text-transform: uppercase;
  letter-spacing: 0.08em;
}

.hero__stat-divider {
  width: 1px;
  height: 40px;
  background: var(--clr-border);
}

/* Hero animation on load */
.hero__content > * {
  opacity: 0;
  transform: translateY(24px);
  animation: fade-up 0.7s ease forwards;
}
.hero__eyebrow   { animation-delay: 0.1s; }
.hero__heading   { animation-delay: 0.25s; }
.hero__subtitle  { animation-delay: 0.4s; }
.hero__cta       { animation-delay: 0.5s; }
.hero__stats     { animation-delay: 0.65s; }

@keyframes fade-up {
  to { opacity: 1; transform: translateY(0); }
}

/* =============================================
   SECTION SHARED
   ============================================= */
.section {
  padding: 100px 0;
}

.section--alt {
  background: var(--clr-forest);
}

.section__header {
  text-align: center;
  margin-bottom: 60px;
}

.section__tag {
  display: inline-block;
  font-size: 0.75rem;
  font-weight: 600;
  letter-spacing: 0.14em;
  text-transform: uppercase;
  color: var(--clr-emerald);
  margin-bottom: 14px;
}

.section__title {
  font-family: var(--font-display);
  font-size: clamp(1.8rem, 3.5vw, 2.8rem);
  font-weight: 700;
  color: var(--clr-white);
  line-height: 1.2;
  letter-spacing: -0.02em;
}

.section__subtitle {
  font-size: 1rem;
  color: var(--clr-muted);
  max-width: 520px;
  margin: 12px auto 0;
  font-weight: 300;
  line-height: 1.7;
}

/* =============================================
   BATCH TOPPERS SECTION
   ============================================= */
.toppers-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(300px, 1fr));
  gap: 24px;
}

/* Glassmorphism card */
.topper-card {
  background: rgba(21, 43, 30, 0.7);
  border: 1px solid var(--clr-border);
  border-radius: var(--radius-lg);
  padding: 28px;
  backdrop-filter: blur(12px);
  -webkit-backdrop-filter: blur(12px);
  transition: transform var(--transition), box-shadow var(--transition), border-color var(--transition);
  position: relative;
  overflow: hidden;
}

.topper-card::before {
  content: '';
  position: absolute;
  top: 0; right: 0;
  width: 120px; height: 120px;
  background: radial-gradient(circle, rgba(16,185,129,0.12) 0%, transparent 70%);
  pointer-events: none;
}

.topper-card:hover {
  transform: translateY(-4px);
  box-shadow: var(--shadow-glow), var(--shadow-card);
  border-color: rgba(16,185,129,0.35);
}

.topper-card__header {
  display: flex;
  align-items: flex-start;
  justify-content: space-between;
  margin-bottom: 20px;
}

.topper-card__batch {
  font-family: var(--font-display);
  font-size: 1.15rem;
  font-weight: 600;
  color: var(--clr-white);
  line-height: 1.3;
}

.topper-card__class {
  font-size: 0.78rem;
  color: var(--clr-subdued);
  margin-top: 2px;
}

.topper-card__avg {
  background: rgba(16,185,129,0.12);
  border: 1px solid rgba(16,185,129,0.22);
  border-radius: var(--radius-sm);
  padding: 6px 12px;
  text-align: right;
  flex-shrink: 0;
}

.topper-card__avg-num {
  font-size: 1.1rem;
  font-weight: 700;
  color: var(--clr-emerald);
  line-height: 1;
}

.topper-card__avg-label {
  font-size: 0.68rem;
  color: var(--clr-subdued);
  margin-top: 2px;
}

.topper-card__list {
  list-style: none;
  display: flex;
  flex-direction: column;
  gap: 10px;
}

.topper-card__item {
  display: flex;
  align-items: center;
  gap: 12px;
}

.topper-card__rank {
  width: 26px; height: 26px;
  border-radius: 50%;
  display: flex; align-items: center; justify-content: center;
  font-size: 0.72rem;
  font-weight: 700;
  flex-shrink: 0;
}

.topper-card__rank--1 { background: #FFD700; color: #5A4000; }
.topper-card__rank--2 { background: #C0C0C0; color: #3A3A3A; }
.topper-card__rank--3 { background: #CD7F32; color: #2A1500; }

.topper-card__name {
  font-size: 0.9rem;
  font-weight: 500;
  color: var(--clr-text);
  flex: 1;
}

.topper-card__marks {
  font-size: 0.85rem;
  font-weight: 600;
  color: var(--clr-emerald);
}

/* =============================================
   FEATURES SECTION
   ============================================= */
.features-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(260px, 1fr));
  gap: 20px;
}

.feature-card {
  background: var(--clr-panel);
  border: 1px solid var(--clr-border);
  border-radius: var(--radius-md);
  padding: 32px 28px;
  transition: transform var(--transition), border-color var(--transition);
  position: relative;
  overflow: hidden;
}

.feature-card:hover {
  transform: translateY(-3px);
  border-color: rgba(16,185,129,0.3);
}

.feature-card__icon {
  width: 52px; height: 52px;
  background: rgba(16,185,129,0.1);
  border: 1px solid rgba(16,185,129,0.2);
  border-radius: var(--radius-md);
  display: flex; align-items: center; justify-content: center;
  font-size: 1.5rem;
  margin-bottom: 20px;
}

.feature-card__title {
  font-size: 1.05rem;
  font-weight: 600;
  color: var(--clr-white);
  margin-bottom: 10px;
}

.feature-card__desc {
  font-size: 0.875rem;
  color: var(--clr-subdued);
  line-height: 1.65;
}

/* =============================================
   HOW IT WORKS SECTION
   ============================================= */
.how-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(220px, 1fr));
  gap: 0;
  position: relative;
}

/* Connecting line between steps */
.how-grid::before {
  content: '';
  position: absolute;
  top: 38px;
  left: calc(12.5% + 26px);
  right: calc(12.5% + 26px);
  height: 1px;
  background: linear-gradient(90deg, transparent, var(--clr-border) 20%, var(--clr-border) 80%, transparent);
  pointer-events: none;
}

.how-step {
  text-align: center;
  padding: 0 20px 0;
  position: relative;
}

.how-step__num {
  width: 52px; height: 52px;
  border-radius: 50%;
  background: var(--clr-panel);
  border: 2px solid var(--clr-border);
  display: flex; align-items: center; justify-content: center;
  font-family: var(--font-display);
  font-size: 1.1rem;
  font-weight: 700;
  color: var(--clr-emerald);
  margin: 0 auto 20px;
  position: relative;
  z-index: 1;
  transition: all var(--transition);
}

.how-step:hover .how-step__num {
  background: var(--clr-emerald);
  color: var(--clr-void);
  border-color: var(--clr-emerald);
  box-shadow: 0 0 24px rgba(16,185,129,0.4);
}

.how-step__title {
  font-size: 0.95rem;
  font-weight: 600;
  color: var(--clr-white);
  margin-bottom: 8px;
}

.how-step__desc {
  font-size: 0.82rem;
  color: var(--clr-subdued);
  line-height: 1.6;
}

/* =============================================
   CTA BANNER
   ============================================= */
.cta-banner {
  background: linear-gradient(135deg, #0E2016 0%, #152B1E 50%, #0E2016 100%);
  border: 1px solid var(--clr-border);
  border-radius: var(--radius-lg);
  padding: 64px 48px;
  text-align: center;
  position: relative;
  overflow: hidden;
}

.cta-banner::before {
  content: '';
  position: absolute;
  top: 50%; left: 50%;
  transform: translate(-50%, -50%);
  width: 500px; height: 300px;
  background: radial-gradient(ellipse, rgba(16,185,129,0.1) 0%, transparent 70%);
  pointer-events: none;
}

.cta-banner__title {
  font-family: var(--font-display);
  font-size: clamp(1.8rem, 3vw, 2.5rem);
  font-weight: 700;
  color: var(--clr-white);
  margin-bottom: 16px;
  position: relative;
}

.cta-banner__sub {
  color: var(--clr-muted);
  font-size: 1rem;
  margin-bottom: 36px;
  font-weight: 300;
  position: relative;
}

.cta-banner__actions {
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 16px;
  flex-wrap: wrap;
  position: relative;
}

/* =============================================
   FOOTER
   ============================================= */
.footer {
  background: var(--clr-void);
  border-top: 1px solid var(--clr-border);
  padding: 60px 0 32px;
}

.footer__grid {
  display: grid;
  grid-template-columns: 2fr 1fr 1fr 1fr;
  gap: 48px;
  margin-bottom: 48px;
}

.footer__brand-logo {
  display: flex;
  align-items: center;
  gap: 10px;
  font-family: var(--font-display);
  font-size: 1.35rem;
  font-weight: 700;
  color: var(--clr-text);
  margin-bottom: 14px;
}

.footer__brand-logo span { color: var(--clr-emerald); }

.footer__brand-logo-icon {
  width: 32px; height: 32px;
  background: var(--clr-emerald);
  border-radius: 8px;
  display: flex; align-items: center; justify-content: center;
  font-size: 1rem;
}

.footer__brand-desc {
  font-size: 0.85rem;
  color: var(--clr-subdued);
  line-height: 1.7;
  max-width: 260px;
}

.footer__col-title {
  font-size: 0.8rem;
  font-weight: 600;
  letter-spacing: 0.1em;
  text-transform: uppercase;
  color: var(--clr-muted);
  margin-bottom: 18px;
}

.footer__links {
  list-style: none;
  display: flex;
  flex-direction: column;
  gap: 10px;
}

.footer__links a {
  font-size: 0.875rem;
  color: var(--clr-subdued);
  transition: color var(--transition);
}

.footer__links a:hover { color: var(--clr-emerald); }

.footer__bottom {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding-top: 24px;
  border-top: 1px solid var(--clr-border);
  gap: 16px;
  flex-wrap: wrap;
}

.footer__copy {
  font-size: 0.8rem;
  color: var(--clr-subdued);
}

.footer__copy span { color: var(--clr-emerald); }

.footer__social {
  display: flex;
  gap: 12px;
}

.footer__social a {
  width: 34px; height: 34px;
  border: 1px solid var(--clr-border);
  border-radius: 8px;
  display: flex; align-items: center; justify-content: center;
  font-size: 0.9rem;
  color: var(--clr-subdued);
  transition: all var(--transition);
}

.footer__social a:hover {
  border-color: var(--clr-emerald);
  color: var(--clr-emerald);
}

/* =============================================
   SCROLL-REVEAL UTILITY
   ============================================= */
.reveal {
  opacity: 0;
  transform: translateY(30px);
  transition: opacity 0.6s ease, transform 0.6s ease;
}
.reveal.visible {
  opacity: 1;
  transform: translateY(0);
}

/* Stagger children */
.reveal-stagger > * {
  opacity: 0;
  transform: translateY(28px);
  transition: opacity 0.55s ease, transform 0.55s ease;
}
.reveal-stagger.visible > *:nth-child(1) { opacity: 1; transform: none; transition-delay: 0.05s; }
.reveal-stagger.visible > *:nth-child(2) { opacity: 1; transform: none; transition-delay: 0.15s; }
.reveal-stagger.visible > *:nth-child(3) { opacity: 1; transform: none; transition-delay: 0.25s; }
.reveal-stagger.visible > *:nth-child(4) { opacity: 1; transform: none; transition-delay: 0.35s; }

/* =============================================
   MOBILE MENU DRAWER
   ============================================= */
.mobile-menu {
  display: none;
  position: fixed;
  inset: 0;
  z-index: 200;
  background: rgba(7,17,10,0.96);
  backdrop-filter: blur(20px);
  flex-direction: column;
  align-items: center;
  justify-content: center;
  gap: 24px;
  padding: 24px;
}

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

.mobile-menu__close {
  position: absolute;
  top: 20px; right: 20px;
  background: transparent;
  border: 1.5px solid var(--clr-border);
  border-radius: var(--radius-sm);
  width: 40px; height: 40px;
  display: flex; align-items: center; justify-content: center;
  color: var(--clr-muted);
  font-size: 1.2rem;
  cursor: pointer;
  transition: all var(--transition);
}
.mobile-menu__close:hover {
  border-color: var(--clr-emerald);
  color: var(--clr-emerald);
}

.mobile-menu a.btn {
  width: 260px;
  font-size: 1rem;
  padding: 14px 28px;
}

/* =============================================
   RESPONSIVE
   ============================================= */
@media (max-width: 768px) {
  .navbar__actions { display: none; }
  .navbar__menu-toggle { display: flex; align-items: center; }

  .hero { padding: 100px 0 60px; }
  .hero__stats { gap: 20px; }

  .toppers-grid { grid-template-columns: 1fr; }
  .features-grid { grid-template-columns: 1fr; }

  .how-grid { grid-template-columns: 1fr 1fr; gap: 32px; }
  .how-grid::before { display: none; }

  .cta-banner { padding: 40px 24px; }

  .footer__grid { grid-template-columns: 1fr 1fr; gap: 32px; }
  .footer__grid > :first-child { grid-column: 1 / -1; }
}

@media (max-width: 480px) {
  .how-grid { grid-template-columns: 1fr; }
  .footer__grid { grid-template-columns: 1fr; }
}

/* =============================================
   SHARED FIXES
   ============================================= */
.btn--full { width: 100%; }
.empty { padding: 24px; text-align: center; opacity: .7; }
.mobile-menu__logo { margin-bottom: 32px; }
body.menu-open { overflow: hidden; }

/* reveal: show every child, not just the first four (cards are loaded from Firebase) */
.reveal-stagger.visible > * { opacity: 1; transform: none; }

/* Light-theme app pages: dark text + readable buttons on light backgrounds */
.student, .apply, .profile, .settings, .notify, .results, .batch, .dashboard { color: #111827; }
:is(.student, .apply, .profile, .settings, .notify, .results, .batch, .dashboard) .btn--ghost,
:is(.student, .apply, .profile, .settings, .notify, .results, .batch, .dashboard) .btn--outline { color: #15803d; border-color: #16a34a; }
:is(.student, .apply, .profile, .settings, .notify, .results, .batch, .dashboard) .btn--ghost:hover,
:is(.student, .apply, .profile, .settings, .notify, .results, .batch, .dashboard) .btn--outline:hover { background: rgba(22,163,74,.1); }