/* ================================================================
   site.css — components shared by every page
   (ambient backdrop, header/nav, buttons, sections, cards,
    marquee, footer, reveal animations)
   Depends on: tokens.css, base.css
   ================================================================ */

body {
  background: var(--color-bg);
  color: var(--color-text);
  font-family: var(--font-body);
}

h1, h2, h3, h4 {
  font-family: var(--font-display);
  font-weight: 700;
  letter-spacing: -0.02em;
}

/* ================================================================
   AMBIENT BACKDROP
   ================================================================ */
.ambient {
  position: fixed;
  inset: 0;
  z-index: -1;
  overflow: hidden;
  pointer-events: none;
  background:
    radial-gradient(ellipse 60% 50% at 50% 0%, rgba(139, 141, 255, 0.12), transparent 60%),
    var(--color-bg);
}
.blob {
  position: absolute;
  border-radius: 50%;
  filter: blur(80px);
  opacity: 0.55;
  will-change: transform;
}
.blob-1 {
  width: 560px; height: 560px;
  top: -120px; left: -100px;
  background: radial-gradient(circle, #5a3cff, transparent 70%);
  animation: float1 22s ease-in-out infinite;
}
.blob-2 {
  width: 480px; height: 480px;
  top: 40%; right: -140px;
  background: radial-gradient(circle, #d65cff, transparent 70%);
  opacity: 0.35;
  animation: float2 26s ease-in-out infinite;
}
.blob-3 {
  width: 420px; height: 420px;
  bottom: -120px; left: 30%;
  background: radial-gradient(circle, #58d6ff, transparent 70%);
  opacity: 0.2;
  animation: float3 30s ease-in-out infinite;
}
@keyframes float1 {
  0%, 100% { transform: translate(0, 0); }
  50%      { transform: translate(60px, 40px); }
}
@keyframes float2 {
  0%, 100% { transform: translate(0, 0); }
  50%      { transform: translate(-50px, 30px); }
}
@keyframes float3 {
  0%, 100% { transform: translate(0, 0); }
  50%      { transform: translate(40px, -30px); }
}

.grid-overlay {
  position: absolute;
  inset: 0;
  background-image:
    linear-gradient(to right, rgba(255, 255, 255, 0.04) 1px, transparent 1px),
    linear-gradient(to bottom, rgba(255, 255, 255, 0.04) 1px, transparent 1px);
  background-size: 56px 56px;
  mask-image: radial-gradient(ellipse 70% 60% at 50% 30%, black 30%, transparent 85%);
  -webkit-mask-image: radial-gradient(ellipse 70% 60% at 50% 30%, black 30%, transparent 85%);
}


/* ================================================================
   HEADER
   ================================================================ */
.site-header {
  position: sticky;
  top: 0;
  z-index: 50;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: var(--space-6);
  padding: var(--space-4) clamp(var(--space-4), 4vw, var(--space-10));
  background: color-mix(in oklab, var(--color-bg) 70%, transparent);
  backdrop-filter: blur(14px) saturate(1.1);
  -webkit-backdrop-filter: blur(14px) saturate(1.1);
  border-bottom: 1px solid transparent;
  transition: border-color 240ms ease, background 240ms ease;
}
.site-header.scrolled {
  border-bottom-color: var(--color-border);
  background: color-mix(in oklab, var(--color-bg) 88%, transparent);
}

.logo {
  display: inline-flex;
  align-items: center;
  gap: var(--space-2);
  font-family: var(--font-display);
  font-weight: 700;
  font-size: var(--text-base);
  letter-spacing: -0.01em;
  color: var(--color-text);
}
.logo em {
  color: var(--color-accent);
  font-style: normal;
}

.site-nav {
  display: flex;
  align-items: center;
  gap: var(--space-6);
  font-size: var(--text-sm);
}
.site-nav a {
  color: var(--color-text-muted);
  font-weight: 500;
  position: relative;
}
.site-nav a:hover { color: var(--color-text); }
.site-nav a.nav-cta {
  padding: 0.55rem var(--space-4);
  border-radius: var(--radius-full);
  background: var(--grad);
  color: #0b0814;
  font-weight: 600;
}
.site-nav a.nav-cta:hover {
  transform: translateY(-1px);
  box-shadow: var(--shadow-glow);
}

.menu-btn {
  display: none;
  width: 40px; height: 40px;
  border-radius: var(--radius-md);
  border: 1px solid var(--color-border);
  background: var(--color-surface);
  position: relative;
}
.menu-btn span {
  position: absolute;
  left: 10px; right: 10px;
  height: 2px;
  background: var(--color-text);
  border-radius: 2px;
  transition: transform 220ms var(--ease-out), opacity 200ms;
}
.menu-btn span:nth-child(1) { top: 13px; }
.menu-btn span:nth-child(2) { top: 19px; }
.menu-btn span:nth-child(3) { top: 25px; }
.menu-btn[aria-expanded='true'] span:nth-child(1) { transform: translateY(6px) rotate(45deg); }
.menu-btn[aria-expanded='true'] span:nth-child(2) { opacity: 0; }
.menu-btn[aria-expanded='true'] span:nth-child(3) { transform: translateY(-6px) rotate(-45deg); }

.mobile-nav {
  display: none;
  position: sticky;
  top: 64px;
  z-index: 49;
  flex-direction: column;
  padding: var(--space-4) var(--space-6) var(--space-6);
  background: var(--color-surface);
  border-bottom: 1px solid var(--color-border);
  gap: var(--space-3);
}
.mobile-nav.open { display: flex; }
.mobile-nav a {
  padding: var(--space-3) 0;
  font-weight: 500;
  border-bottom: 1px solid var(--color-border);
}
.mobile-nav a:last-child { border: none; }
.mobile-nav .nav-cta {
  margin-top: var(--space-2);
  background: var(--grad);
  color: #0b0814;
  padding: var(--space-3) var(--space-4);
  border-radius: var(--radius-full);
  text-align: center;
  border: none;
}

.badge {
  display: inline-flex;
  align-items: center;
  gap: var(--space-2);
  padding: 0.4rem 0.9rem;
  border-radius: var(--radius-full);
  background: color-mix(in oklab, var(--color-primary) 14%, transparent);
  border: 1px solid color-mix(in oklab, var(--color-primary) 35%, transparent);
  color: color-mix(in oklab, var(--color-primary) 80%, white);
  font-size: var(--text-xs);
  font-weight: 500;
  letter-spacing: 0.02em;
  margin-bottom: var(--space-6);
}
.pulse {
  width: 8px; height: 8px;
  border-radius: 50%;
  background: #8efc8e;
  box-shadow: 0 0 0 0 rgba(142, 252, 142, 0.5);
  animation: pulse 1.8s ease-out infinite;
}
@keyframes pulse {
  0% { box-shadow: 0 0 0 0 rgba(142, 252, 142, 0.5); }
  70% { box-shadow: 0 0 0 10px rgba(142, 252, 142, 0); }
  100% { box-shadow: 0 0 0 0 rgba(142, 252, 142, 0); }
}

.grad {
  background: var(--grad);
  -webkit-background-clip: text;
  background-clip: text;
  color: transparent;
  background-size: 200% 200%;
  animation: grad-shift 8s ease-in-out infinite;
}
@keyframes grad-shift {
  0%, 100% { background-position: 0% 50%; }
  50%      { background-position: 100% 50%; }
}

.hero-ctas {
  display: flex;
  flex-wrap: wrap;
  gap: var(--space-3);
  margin-bottom: var(--space-12);
}

.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: var(--space-2);
  padding: 0.85rem 1.4rem;
  border-radius: var(--radius-full);
  font-size: var(--text-sm);
  font-weight: 600;
  letter-spacing: -0.005em;
  border: 1px solid transparent;
  white-space: nowrap;
}
.btn svg { transition: transform var(--transition-interactive); }
.btn-primary {
  background: var(--grad);
  color: #0b0814;
  box-shadow: 0 8px 30px -12px rgba(139, 141, 255, 0.6);
}
.btn-primary:hover { transform: translateY(-1px); box-shadow: 0 14px 40px -10px rgba(139, 141, 255, 0.7); }
.btn-primary:hover svg { transform: translateX(3px); }
.btn-primary:active { transform: translateY(0); }

.btn-ghost {
  background: color-mix(in oklab, var(--color-surface-2) 70%, transparent);
  border-color: var(--color-border);
  color: var(--color-text);
}
.btn-ghost:hover { background: var(--color-surface-3); border-color: var(--color-border-strong); }

.btn.full { width: 100%; }

.marquee {
  grid-column: 1 / -1;
  margin-top: var(--space-12);
  overflow: hidden;
  mask-image: linear-gradient(to right, transparent, black 10%, black 90%, transparent);
  -webkit-mask-image: linear-gradient(to right, transparent, black 10%, black 90%, transparent);
  display: flex;
  gap: var(--space-6);
}
.marquee .track {
  display: flex;
  gap: var(--space-6);
  flex-shrink: 0;
  animation: scroll 40s linear infinite;
  font-family: var(--font-display);
  font-size: var(--text-lg);
  font-weight: 600;
  color: var(--color-text-muted);
  white-space: nowrap;
}
.marquee .track span:nth-child(2n) { color: var(--color-border-strong); }
@keyframes scroll {
  from { transform: translateX(0); }
  to   { transform: translateX(-100%); }
}

/* ================================================================
   SECTIONS (common)
   ================================================================ */
.section {
  position: relative;
  max-width: var(--content);
  margin: 0 auto;
  padding: clamp(var(--space-16), 10vw, var(--space-32)) clamp(var(--space-4), 4vw, var(--space-10));
}

.section-head {
  max-width: 860px;
  margin-bottom: var(--space-12);
}
.eyebrow {
  display: inline-block;
  font-size: var(--text-xs);
  text-transform: uppercase;
  letter-spacing: 0.18em;
  color: var(--color-primary-hover);
  font-weight: 600;
  margin-bottom: var(--space-3);
}
.section-head h2 {
  font-size: clamp(2rem, 1.2rem + 2.5vw, 3.25rem);
  letter-spacing: -0.03em;
  margin-bottom: var(--space-4);
}
.section-lede {
  color: var(--color-text-muted);
  font-size: var(--text-base);
  max-width: 62ch;
}

.links { display: flex; gap: var(--space-3); flex-wrap: wrap; }
.link-pill {
  display: inline-flex;
  align-items: center;
  gap: var(--space-2);
  padding: 0.5rem 0.9rem;
  font-size: var(--text-sm);
  font-weight: 500;
  border-radius: var(--radius-full);
  border: 1px solid var(--color-border);
  background: var(--color-surface-3);
  color: var(--color-text);
}
.link-pill:hover {
  border-color: var(--color-primary);
  color: var(--color-primary-hover);
  transform: translateY(-1px);
}


/* ================================================================
   CARD GRID (feature cards, project cards, topic cards)
   ================================================================ */
.card-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(260px, 1fr));
  gap: var(--space-5);
}
.card {
  position: relative;
  padding: var(--space-8);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-xl);
  background: linear-gradient(180deg, var(--color-surface-2), var(--color-surface));
  overflow: hidden;
  transition: transform 300ms var(--ease-out), border-color 240ms, box-shadow 240ms;
}
.card::after {
  content: '';
  position: absolute; inset: 0;
  border-radius: inherit;
  padding: 1px;
  background: var(--grad);
  -webkit-mask: linear-gradient(#000 0 0) content-box, linear-gradient(#000 0 0);
  mask: linear-gradient(#000 0 0) content-box, linear-gradient(#000 0 0);
  -webkit-mask-composite: xor;
  mask-composite: exclude;
  opacity: 0;
  transition: opacity 280ms;
  pointer-events: none;
}
.card:hover {
  transform: translateY(-3px);
  box-shadow: var(--shadow-md);
}
.card:hover::after { opacity: 1; }

.card-icon {
  width: 48px; height: 48px;
  display: grid; place-items: center;
  border-radius: var(--radius-md);
  background: color-mix(in oklab, var(--color-primary) 14%, transparent);
  color: var(--color-primary-hover);
  margin-bottom: var(--space-5);
}
.card-icon svg { width: 24px; height: 24px; }
.card h3 {
  font-size: var(--text-lg);
  font-weight: 700;
  margin-bottom: var(--space-2);
}
.card p {
  color: var(--color-text-muted);
  font-size: var(--text-sm);
  margin-bottom: var(--space-5);
}
.tags {
  display: flex;
  flex-wrap: wrap;
  gap: var(--space-2);
  list-style: none;
}
.tags li {
  font-family: var(--font-mono);
  font-size: 0.7rem;
  padding: 0.2rem 0.55rem;
  border-radius: var(--radius-sm);
  background: var(--color-surface-3);
  color: var(--color-text-muted);
  border: 1px solid var(--color-border);
}

/* ================================================================
   FOOTER
   ================================================================ */
.site-footer {
  border-top: 1px solid var(--color-border);
  padding: var(--space-16) clamp(var(--space-4), 4vw, var(--space-10)) var(--space-8);
  background: var(--color-bg-deep);
}
.foot-grid {
  max-width: var(--content);
  margin: 0 auto;
  display: grid;
  grid-template-columns: minmax(0, 1.5fr) repeat(2, minmax(0, 1fr));
  gap: var(--space-10);
  padding-bottom: var(--space-10);
  border-bottom: 1px solid var(--color-border);
}
.site-footer .logo { margin-bottom: var(--space-4); }
.foot-bio {
  color: var(--color-text-muted);
  font-size: var(--text-sm);
  max-width: 42ch;
}
.foot-grid h4 {
  font-family: var(--font-display);
  font-size: var(--text-sm);
  font-weight: 600;
  margin-bottom: var(--space-4);
  color: var(--color-text);
}
.foot-grid ul { list-style: none; display: flex; flex-direction: column; gap: var(--space-2); }
.foot-grid a {
  color: var(--color-text-muted);
  font-size: var(--text-sm);
}
.foot-grid a:hover { color: var(--color-primary-hover); }

.foot-bottom {
  max-width: var(--content);
  margin: var(--space-6) auto 0;
  display: flex;
  justify-content: space-between;
  gap: var(--space-4);
  font-size: var(--text-xs);
  color: var(--color-text-faint);
  flex-wrap: wrap;
}

/* ================================================================
   SCROLL REVEAL (CLS-safe: opacity only)
   ================================================================ */
.reveal { opacity: 1; }
@supports (animation-timeline: view()) {
  .reveal {
    opacity: 0;
    animation: reveal-fade linear both;
    animation-timeline: view();
    animation-range: entry 0% entry 60%;
  }
}
@keyframes reveal-fade { to { opacity: 1; } }

/* JS-driven fallback for older browsers */
.js-reveal { opacity: 0; transform: translateY(12px); transition: opacity 700ms var(--ease-out), transform 700ms var(--ease-out); }
.js-reveal.visible { opacity: 1; transform: translateY(0); }

/* ================================================================
   UTILITIES
   ================================================================ */
.rule {
  height: 1px;
  border: 0;
  background: linear-gradient(90deg, transparent, var(--color-border-strong), transparent);
  margin: 0;
}
.center { text-align: center; }
.section-cta {
  display: flex;
  justify-content: center;
  margin-top: var(--space-10);
}

/* ================================================================
   RESPONSIVE (shared)
   ================================================================ */
@media (max-width: 960px) {
  .foot-grid { grid-template-columns: 1fr 1fr; }
}

@media (max-width: 720px) {
  .site-nav { display: none; }
  .menu-btn { display: block; }
  .foot-grid { grid-template-columns: 1fr; gap: var(--space-8); }
  .foot-bottom { flex-direction: column; gap: var(--space-2); }
}