/* ═══════════════════════════════════════════════════
   BIONOTES — Global CSS v2.0
   Design System | Reset | Typography | Components
═══════════════════════════════════════════════════ */

/* ── DARK MODE TOKENS (default) ── */
:root {
  --clr-primary:    #00FFB2;
  --clr-secondary:  #00D9FF;
  --clr-accent:     #7B61FF;
  --clr-bg:         #080810;
  --clr-bg-2:       #0d0d1a;
  --clr-surface:    rgba(255,255,255,0.04);
  --clr-surface-2:  rgba(255,255,255,0.08);
  --clr-surface-3:  rgba(255,255,255,0.12);
  --clr-border:     rgba(255,255,255,0.07);
  --clr-border-hi:  rgba(0,255,178,0.25);
  --clr-text:       #E8E8E8;
  --clr-text-dim:   #888;
  --clr-text-mute:  #3A3A4A;

  --glow-green:   0 0 20px rgba(0,255,178,0.35), 0 0 60px rgba(0,255,178,0.12);
  --glow-cyan:    0 0 20px rgba(0,217,255,0.35), 0 0 60px rgba(0,217,255,0.12);
  --glow-purple:  0 0 20px rgba(123,97,255,0.35);
  --glow-subtle:  0 8px 40px rgba(0,0,0,0.6);

  --radius-sm: 8px;
  --radius-md: 14px;
  --radius-lg: 20px;
  --radius-xl: 28px;
  --radius-2xl: 36px;

  --trans-fast:   0.15s cubic-bezier(0.4,0,0.2,1);
  --trans-normal: 0.3s  cubic-bezier(0.4,0,0.2,1);
  --trans-slow:   0.6s  cubic-bezier(0.4,0,0.2,1);
  --trans-spring: 0.4s  cubic-bezier(0.34,1.56,0.64,1);

  --font-head: 'Orbitron', sans-serif;
  --font-body: 'Inter', sans-serif;
  --font-mono: 'Space Mono', monospace;

  --nav-h: 72px;
}

/* ── LIGHT MODE TOKENS ── */
[data-theme="light"] {
  --clr-bg:         #f0f4ff;
  --clr-bg-2:       #e8eeff;
  --clr-surface:    rgba(255,255,255,0.7);
  --clr-surface-2:  rgba(255,255,255,0.85);
  --clr-surface-3:  rgba(255,255,255,0.95);
  --clr-border:     rgba(0,0,0,0.08);
  --clr-border-hi:  rgba(0,180,130,0.3);
  --clr-text:       #1a1a2e;
  --clr-text-dim:   #556;
  --clr-text-mute:  #aab;
  --glow-green:   0 0 20px rgba(0,200,140,0.2), 0 0 40px rgba(0,200,140,0.08);
  --glow-subtle:  0 8px 40px rgba(0,0,0,0.1);
}

/* ── GLOBAL COLOR TRANSITION ── */
html {
  transition: background-color 0.4s ease, color 0.4s ease;
}

/* ── RESET ── */
*, *::before, *::after { box-sizing: border-box; margin: 0; padding: 0; }
html { scroll-behavior: smooth; }
body {
  font-family: var(--font-body);
  background: var(--clr-bg);
  color: var(--clr-text);
  line-height: 1.6;
  min-height: 100vh;
  overflow-x: hidden;
  transition: background 0.4s ease, color 0.4s ease;
}
a { color: inherit; text-decoration: none; }
button { cursor: pointer; font-family: inherit; border: none; background: none; }
img { display: block; max-width: 100%; }
ul { list-style: none; }

/* ── SCROLLBAR ── */
::-webkit-scrollbar { width: 4px; }
::-webkit-scrollbar-track { background: var(--clr-bg); }
::-webkit-scrollbar-thumb {
  background: linear-gradient(180deg, var(--clr-primary), var(--clr-accent));
  border-radius: 99px;
}

/* ── SELECTION ── */
::selection { background: rgba(0,255,178,0.2); color: var(--clr-primary); }

/* ── TYPOGRAPHY ── */
h1, h2, h3, h4 {
  font-family: var(--font-head);
  line-height: 1.15;
  letter-spacing: -0.02em;
}

/* ── GRADIENT TEXT ── */
.gradient-text {
  background: linear-gradient(135deg, var(--clr-primary) 0%, var(--clr-secondary) 100%);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
}
.gradient-text-2 {
  background: linear-gradient(135deg, var(--clr-secondary) 0%, var(--clr-accent) 100%);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
}

/* ── SECTION TAG ── */
.section-tag {
  display: inline-block;
  font-family: var(--font-mono);
  font-size: 0.68rem;
  letter-spacing: 0.25em;
  color: var(--clr-primary);
  background: rgba(0,255,178,0.07);
  border: 1px solid rgba(0,255,178,0.2);
  padding: 5px 16px;
  border-radius: 99px;
  margin-bottom: 1rem;
  text-transform: uppercase;
}

/* ── SECTION HEADER ── */
.section-header {
  text-align: center;
  margin-bottom: 3.5rem;
}
.section-title {
  font-size: clamp(2rem, 4vw, 3.2rem);
  margin-bottom: 0.75rem;
  color: var(--clr-text);
}
.section-sub {
  color: var(--clr-text-dim);
  font-size: 1rem;
  max-width: 520px;
  margin: 0 auto;
}

/* ── GLASSMORPHISM CARD BASE ── */
.glass-card {
  background: var(--clr-surface);
  backdrop-filter: blur(20px);
  -webkit-backdrop-filter: blur(20px);
  border: 1px solid var(--clr-border);
  border-radius: var(--radius-lg);
}
[data-theme="light"] .glass-card {
  background: rgba(255,255,255,0.6);
  border-color: rgba(0,0,0,0.06);
  box-shadow: 0 4px 24px rgba(0,0,0,0.08);
}

/* ── BUTTONS ── */
.btn-primary {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  position: relative;
  overflow: hidden;
  background: linear-gradient(135deg, var(--clr-primary), var(--clr-secondary));
  color: #000;
  font-family: var(--font-head);
  font-size: 0.8rem;
  font-weight: 700;
  letter-spacing: 0.06em;
  padding: 14px 30px;
  border-radius: 99px;
  transition: transform var(--trans-normal), box-shadow var(--trans-normal);
  cursor: none;
  border: none;
  text-decoration: none;
}
.btn-primary:hover {
  transform: translateY(-3px) scale(1.04);
  box-shadow: var(--glow-green), 0 20px 40px rgba(0,255,178,0.2);
}
.btn-primary:active { transform: translateY(0) scale(0.97); }
.btn-glow {
  position: absolute;
  inset: -50%;
  background: radial-gradient(circle, rgba(255,255,255,0.3), transparent 70%);
  opacity: 0;
  transition: opacity 0.5s;
  pointer-events: none;
}
.btn-primary:hover .btn-glow { opacity: 1; }

.btn-ghost {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  background: transparent;
  color: var(--clr-text-dim);
  font-family: var(--font-head);
  font-size: 0.8rem;
  font-weight: 600;
  letter-spacing: 0.05em;
  padding: 13px 28px;
  border-radius: 99px;
  border: 1px solid var(--clr-border);
  transition: all var(--trans-normal);
  cursor: none;
  text-decoration: none;
}
.btn-ghost:hover {
  border-color: var(--clr-primary);
  color: var(--clr-primary);
  background: rgba(0,255,178,0.06);
  transform: translateY(-2px);
}

/* ── NAVBAR ── */
.navbar {
  position: fixed;
  top: 0; left: 0; right: 0;
  z-index: 1000;
  height: var(--nav-h);
  background: rgba(8,8,16,0.5);
  backdrop-filter: blur(24px) saturate(180%);
  -webkit-backdrop-filter: blur(24px) saturate(180%);
  border-bottom: 1px solid var(--clr-border);
  transition: background var(--trans-normal), box-shadow var(--trans-normal);
}
[data-theme="light"] .navbar {
  background: rgba(240,244,255,0.7);
  border-bottom-color: rgba(0,0,0,0.06);
}
.navbar.scrolled {
  background: rgba(8,8,16,0.95);
  box-shadow: 0 1px 0 var(--clr-border-hi), 0 4px 30px rgba(0,0,0,0.5);
}
[data-theme="light"] .navbar.scrolled {
  background: rgba(240,244,255,0.97);
  box-shadow: 0 1px 0 rgba(0,180,130,0.2), 0 4px 20px rgba(0,0,0,0.08);
}
.nav-inner {
  max-width: 1360px;
  margin: 0 auto;
  height: 100%;
  display: flex;
  align-items: center;
  gap: 1.5rem;
  padding: 0 2rem;
}
.nav-logo {
  display: flex;
  align-items: center;
  gap: 10px;
  flex-shrink: 0;
  text-decoration: none;
}
.logo-icon {
  font-size: 1.5rem;
  color: var(--clr-primary);
  filter: drop-shadow(0 0 10px var(--clr-primary));
  transition: filter 0.3s;
}
.nav-logo:hover .logo-icon {
  filter: drop-shadow(0 0 20px var(--clr-primary));
}
.logo-text {
  font-family: var(--font-head);
  font-size: 1.1rem;
  font-weight: 800;
  color: var(--clr-text);
  letter-spacing: 0.08em;
}
.nav-links {
  display: flex;
  align-items: center;
  gap: 0.25rem;
  margin-left: auto;
}
.nav-link {
  font-family: var(--font-head);
  font-size: 0.7rem;
  font-weight: 600;
  letter-spacing: 0.1em;
  color: var(--clr-text-dim);
  padding: 8px 16px;
  border-radius: var(--radius-sm);
  transition: color var(--trans-fast), background var(--trans-fast);
  text-decoration: none;
  position: relative;
}
.nav-link::after {
  content: '';
  position: absolute;
  bottom: 2px; left: 50%;
  transform: translateX(-50%) scaleX(0);
  width: 20px;
  height: 2px;
  background: var(--clr-primary);
  border-radius: 99px;
  transition: transform var(--trans-spring);
}
.nav-link:hover::after, .nav-link.active::after { transform: translateX(-50%) scaleX(1); }
.nav-link:hover, .nav-link.active { color: var(--clr-primary); background: rgba(0,255,178,0.06); }
.nav-cta {
  font-family: var(--font-head);
  font-size: 0.72rem;
  font-weight: 700;
  letter-spacing: 0.08em;
  color: #000;
  background: linear-gradient(135deg, var(--clr-primary), var(--clr-secondary));
  padding: 9px 20px;
  border-radius: 99px;
  border: none;
  transition: all var(--trans-fast);
  flex-shrink: 0;
}
.nav-cta:hover {
  transform: scale(1.05);
  box-shadow: 0 0 20px rgba(0,255,178,0.4);
}
.nav-hamburger {
  display: none;
  flex-direction: column;
  gap: 5px;
  padding: 8px;
  margin-left: 0.5rem;
  border-radius: var(--radius-sm);
  transition: background var(--trans-fast);
}
.nav-hamburger:hover { background: var(--clr-surface-2); }
.nav-hamburger span {
  display: block;
  width: 22px;
  height: 2px;
  background: var(--clr-text-dim);
  border-radius: 2px;
  transition: all 0.3s ease;
}
.nav-hamburger.open span:nth-child(1) { transform: rotate(45deg) translate(5px, 5px); }
.nav-hamburger.open span:nth-child(2) { opacity: 0; transform: translateX(-10px); }
.nav-hamburger.open span:nth-child(3) { transform: rotate(-45deg) translate(5px, -5px); }

.nav-mobile-menu {
  display: none;
  flex-direction: column;
  background: rgba(8,8,16,0.98);
  border-top: 1px solid var(--clr-border);
  padding: 1.5rem 2rem;
  gap: 0.5rem;
}
[data-theme="light"] .nav-mobile-menu { background: rgba(240,244,255,0.98); }
.nav-mobile-menu.open { display: flex; }
.mobile-link {
  padding: 12px 0;
  font-family: var(--font-head);
  font-size: 0.85rem;
  color: var(--clr-text-dim);
  border-bottom: 1px solid var(--clr-border);
  text-decoration: none;
  letter-spacing: 0.06em;
  transition: color var(--trans-fast), padding var(--trans-fast);
}
.mobile-link:last-child { border-bottom: none; }
.mobile-link:hover { color: var(--clr-primary); padding-left: 8px; }

/* ── SUBJECTS SECTION (Homepage) ── */
.subjects-section {
  padding: 6rem 2rem;
  max-width: 1360px;
  margin: 0 auto;
  position: relative;
  z-index: 1;
}
.subjects-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
  gap: 1.5rem;
}

/* ── HOW IT WORKS ── */
.how-section {
  padding: 6rem 2rem;
  position: relative;
  z-index: 1;
}
.how-section::before {
  content: '';
  position: absolute;
  inset: 0;
  background: linear-gradient(180deg, transparent, rgba(0,255,178,0.02), transparent);
  pointer-events: none;
}
.steps-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(240px, 1fr));
  gap: 1.5rem;
  max-width: 960px;
  margin: 0 auto;
}
.step-card {
  background: var(--clr-surface);
  backdrop-filter: blur(12px);
  border: 1px solid var(--clr-border);
  border-radius: var(--radius-xl);
  padding: 2.5rem 2rem;
  text-align: center;
  position: relative;
  overflow: hidden;
  transition: all var(--trans-normal);
}
.step-card::before {
  content: attr(data-step);
  position: absolute;
  top: 1.25rem; right: 1.25rem;
  font-family: var(--font-mono);
  font-size: 0.6rem;
  color: var(--clr-text-mute);
  letter-spacing: 0.1em;
}
.step-card::after {
  content: '';
  position: absolute;
  inset: 0;
  background: radial-gradient(circle at 50% 0%, rgba(0,255,178,0.08), transparent 60%);
  opacity: 0;
  transition: opacity var(--trans-normal);
}
.step-card:hover {
  border-color: var(--clr-border-hi);
  background: var(--clr-surface-2);
  transform: translateY(-6px);
  box-shadow: 0 20px 60px rgba(0,0,0,0.4), var(--glow-green);
}
.step-card:hover::after { opacity: 1; }
.step-icon {
  font-size: 2.8rem;
  margin-bottom: 1.25rem;
  filter: drop-shadow(0 0 12px rgba(0,255,178,0.3));
  transition: filter 0.3s, transform 0.3s;
}
.step-card:hover .step-icon {
  filter: drop-shadow(0 0 20px rgba(0,255,178,0.6));
  transform: scale(1.1) rotate(5deg);
}
.step-card h3 {
  font-size: 1rem;
  font-family: var(--font-head);
  color: var(--clr-text);
  margin-bottom: 0.6rem;
}
.step-card p { font-size: 0.88rem; color: var(--clr-text-dim); line-height: 1.7; }

/* ── FOOTER ── */
.footer {
  border-top: 1px solid var(--clr-border);
  padding: 5rem 2rem 2rem;
  position: relative;
  z-index: 1;
}
.footer-inner { max-width: 1360px; margin: 0 auto; }
.footer-grid {
  display: grid;
  grid-template-columns: 2fr 1fr 1fr 1fr;
  gap: 3rem;
  margin-bottom: 3rem;
}
.footer-brand {
  display: flex;
  flex-direction: column;
  gap: 0.75rem;
}
.footer-logo {
  font-family: var(--font-head);
  font-size: 1.3rem;
  font-weight: 800;
  color: var(--clr-primary);
  display: flex;
  align-items: center;
  gap: 10px;
  letter-spacing: 0.08em;
  filter: drop-shadow(0 0 20px rgba(0,255,178,0.3));
  text-decoration: none;
}
.footer-brand-desc {
  font-size: 0.85rem;
  color: var(--clr-text-dim);
  line-height: 1.7;
  max-width: 300px;
}
.footer-tag {
  font-family: var(--font-mono);
  font-size: 0.62rem;
  letter-spacing: 0.1em;
  color: var(--clr-primary);
  margin-top: 0.25rem;
}
.footer-col {
  display: flex;
  flex-direction: column;
  gap: 0.6rem;
}
.footer-col-title {
  font-family: var(--font-head);
  font-size: 0.68rem;
  letter-spacing: 0.15em;
  text-transform: uppercase;
  color: var(--clr-text);
  margin-bottom: 0.35rem;
}
.footer-link {
  font-size: 0.82rem;
  color: var(--clr-text-dim);
  text-decoration: none;
  transition: color var(--trans-fast), padding-left var(--trans-fast);
  display: block;
}
.footer-link:hover { color: var(--clr-primary); padding-left: 4px; }
.footer-muted {
  font-size: 0.8rem;
  color: var(--clr-text-mute);
  font-family: var(--font-mono);
}
.footer-bottom {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding-top: 2rem;
  border-top: 1px solid var(--clr-border);
  flex-wrap: wrap;
  gap: 1rem;
}
.footer-copy {
  font-size: 0.75rem;
  color: var(--clr-text-mute);
  font-family: var(--font-mono);
}
.footer-badges {
  display: flex;
  gap: 0.5rem;
  flex-wrap: wrap;
}
.footer-badge {
  font-family: var(--font-mono);
  font-size: 0.6rem;
  letter-spacing: 0.08em;
  color: var(--clr-text-mute);
  border: 1px solid var(--clr-border);
  padding: 3px 10px;
  border-radius: 4px;
}
@media (max-width: 900px) {
  .footer-grid { grid-template-columns: 1fr 1fr; }
  .footer-brand { grid-column: 1 / -1; }
}
@media (max-width: 500px) {
  .footer-grid { grid-template-columns: 1fr; }
  .footer-bottom { flex-direction: column; text-align: center; }
}

/* ── MODAL ── */
.modal-overlay {
  position: fixed;
  inset: 0;
  background: rgba(0,0,0,0.85);
  backdrop-filter: blur(16px);
  -webkit-backdrop-filter: blur(16px);
  z-index: 5000;
  display: flex;
  align-items: center;
  justify-content: center;
  padding: 2rem;
  opacity: 0;
  pointer-events: none;
  transition: opacity var(--trans-normal);
}
.modal-overlay.open {
  opacity: 1;
  pointer-events: all;
}
.modal-box {
  background: linear-gradient(145deg, #111118, #0d0d18);
  border: 1px solid var(--clr-border-hi);
  border-radius: var(--radius-2xl);
  padding: 2.5rem;
  max-width: 520px;
  width: 100%;
  box-shadow: var(--glow-green), 0 40px 80px rgba(0,0,0,0.8);
  transform: scale(0.92) translateY(30px);
  transition: transform var(--trans-spring);
  position: relative;
  overflow: hidden;
}
.modal-box::before {
  content: '';
  position: absolute;
  top: 0; left: 0; right: 0;
  height: 2px;
  background: linear-gradient(90deg, transparent, var(--clr-primary), transparent);
}
.modal-overlay.open .modal-box { transform: scale(1) translateY(0); }
[data-theme="light"] .modal-box { background: linear-gradient(145deg, #ffffff, #f5f7ff); }
.modal-header {
  display: flex;
  align-items: flex-start;
  justify-content: space-between;
  gap: 1rem;
  margin-bottom: 1.5rem;
}
.modal-title {
  font-size: 1.1rem;
  font-family: var(--font-head);
  color: var(--clr-text);
  line-height: 1.4;
}
.modal-close {
  color: var(--clr-text-dim);
  font-size: 1.2rem;
  padding: 4px 10px;
  border-radius: var(--radius-sm);
  transition: color var(--trans-fast), background var(--trans-fast);
  flex-shrink: 0;
}
.modal-close:hover { color: #fff; background: var(--clr-surface-2); }
.modal-meta {
  font-size: 0.85rem;
  color: var(--clr-text-dim);
  margin-bottom: 1.5rem;
  line-height: 1.8;
  background: var(--clr-surface);
  padding: 1rem 1.25rem;
  border-radius: var(--radius-md);
  border: 1px solid var(--clr-border);
}
.modal-meta strong { color: var(--clr-text); font-family: var(--font-mono); font-size: 0.75rem; letter-spacing: 0.05em; }
.modal-actions { display: flex; gap: 1rem; flex-wrap: wrap; }

/* Modal iframe preview */
.modal-preview-wrap {
  margin-bottom: 1.5rem;
  border-radius: var(--radius-md);
  overflow: hidden;
  border: 1px solid var(--clr-border);
  height: 240px;
  background: #000;
  position: relative;
}
.modal-preview-wrap iframe {
  width: 100%; height: 100%;
  border: none;
}
.modal-preview-placeholder {
  position: absolute;
  inset: 0;
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  gap: 0.5rem;
  color: var(--clr-text-mute);
  font-size: 0.75rem;
  font-family: var(--font-mono);
}
.modal-preview-placeholder-icon { font-size: 2rem; }

/* ── ANIMATIONS ── */
@keyframes fadeInUp {
  from { opacity: 0; transform: translateY(30px); }
  to   { opacity: 1; transform: translateY(0); }
}
@keyframes fadeIn {
  from { opacity: 0; }
  to   { opacity: 1; }
}
@keyframes pulse {
  0%, 100% { opacity: 1; }
  50% { opacity: 0.4; }
}
@keyframes float {
  0%, 100% { transform: translateY(0); }
  50% { transform: translateY(-14px); }
}
@keyframes spin {
  from { transform: rotate(0deg); }
  to   { transform: rotate(360deg); }
}
@keyframes shimmer {
  from { background-position: -200% center; }
  to   { background-position: 200% center; }
}
@keyframes breathe {
  0%, 100% { box-shadow: 0 0 20px rgba(0,255,178,0.2); }
  50%       { box-shadow: 0 0 40px rgba(0,255,178,0.5), 0 0 80px rgba(0,255,178,0.1); }
}

.animate-in { animation: fadeInUp 0.7s cubic-bezier(0.4,0,0.2,1) both; }

/* ── BREADCRUMB ── */
.breadcrumb {
  display: flex;
  align-items: center;
  gap: 0.5rem;
  margin-bottom: 2rem;
  font-size: 0.8rem;
  color: var(--clr-text-mute);
  font-family: var(--font-mono);
}
.bc-link {
  color: var(--clr-text-dim);
  text-decoration: none;
  transition: color var(--trans-fast);
}
.bc-link:hover { color: var(--clr-primary); }
.bc-sep { color: var(--clr-text-mute); }
.bc-current { color: var(--clr-primary); }

/* ── FILTER BAR ── */
.filter-bar {
  display: flex;
  align-items: center;
  gap: 0.5rem;
  flex-wrap: wrap;
  margin-bottom: 2.5rem;
}
.filter-btn {
  font-family: var(--font-head);
  font-size: 0.68rem;
  letter-spacing: 0.08em;
  color: var(--clr-text-dim);
  background: var(--clr-surface);
  border: 1px solid var(--clr-border);
  padding: 8px 18px;
  border-radius: 99px;
  transition: all var(--trans-fast);
  cursor: none;
}
.filter-btn:hover, .filter-btn.active {
  color: #000;
  background: linear-gradient(135deg, var(--clr-primary), var(--clr-secondary));
  border-color: transparent;
  box-shadow: 0 0 16px rgba(0,255,178,0.3);
}

/* ── RESPONSIVE ── */
@media (max-width: 900px) {
  .nav-links, .nav-cta { display: none; }
  .nav-hamburger       { display: flex; }
}
@media (max-width: 768px) {
  .subjects-grid { grid-template-columns: 1fr 1fr; }
  .modal-box { padding: 1.5rem; }
}
@media (max-width: 480px) {
  .subjects-grid { grid-template-columns: 1fr; }
}