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

body {
  font-family: 'Inter', system-ui, sans-serif;
  min-height: 100vh;
  display: flex;
  flex-direction: column;
  background: #fff;
  color: #111827;
}

.dark body {
  background: #111827;
  color: #f3f4f6;
}

img { display: block; max-width: 100%; }
a { color: inherit; text-decoration: none; }

.hidden { display: none; }

/* === Header === */
.site-header {
  padding: 1.5rem 1rem;
}

.site-header-inner {
  max-width: 42rem;
  margin: 0 auto;
  display: flex;
  justify-content: flex-end;
}

#dark-mode-toggle {
  background: none;
  border: none;
  cursor: pointer;
  padding: 0.5rem;
  border-radius: 0.5rem;
  color: #4b5563;
  transition: background-color 0.2s;
}

#dark-mode-toggle:hover {
  background: #f3f4f6;
}

.dark #dark-mode-toggle {
  color: #9ca3af;
}

.dark #dark-mode-toggle:hover {
  background: #1f2937;
}

.toggle-icon {
  width: 1.25rem;
  height: 1.25rem;
  display: block;
}

/* === Footer === */
.site-footer {
  padding: 2rem 1rem;
}

.site-footer p {
  max-width: 42rem;
  margin: 0 auto;
  text-align: center;
  font-size: 0.875rem;
  color: #6b7280;
}

/* === Hero === */
#hero {
  position: relative;
  min-height: 85vh;
  display: flex;
  align-items: center;
  justify-content: center;
  overflow: hidden;
  padding: 0 1rem;
}

.hero-bg {
  position: absolute;
  inset: 0;
  width: 100%;
  height: 100%;
}

/* --- Hero content overlay --- */
.hero-content {
  position: relative;
  z-index: 10;
  text-align: center;
  max-width: 48rem;
  animation: hero-fade-up 1s ease-out 0.3s forwards;
}

.hero-logo-wrap {
  display: inline-block;
  margin-bottom: 1.5rem;
}

.hero-logo-ring {
  position: relative;
  width: 7rem;
  height: 7rem;
  margin: 0 auto;
}

@media (min-width: 640px) {
  .hero-logo-ring {
    width: 8rem;
    height: 8rem;
  }
}

.hero-logo-glow {
  position: absolute;
  inset: 0;
  border-radius: 1rem;
  background: conic-gradient(
    from 0deg,
    rgba(99,102,241,0.4),
    rgba(168,85,247,0.4),
    rgba(236,72,153,0.4),
    rgba(99,102,241,0.4)
  );
  filter: blur(16px);
  animation: logo-spin 8s linear infinite, pulse 2s ease-in-out infinite;
}

@keyframes logo-spin {
  to { transform: rotate(360deg); }
}

@keyframes pulse {
  0%, 100% { opacity: 1; }
  50% { opacity: 0.5; }
}

.hero-logo-img {
  position: relative;
  width: 100%;
  height: 100%;
  border-radius: 1rem;
  box-shadow: 0 25px 50px -12px rgba(0,0,0,0.25);
}

.hero-title {
  font-size: 3rem;
  font-weight: 700;
  margin-bottom: 1rem;
}

@media (min-width: 640px) {
  .hero-title {
    font-size: 4.5rem;
  }
}

.hero-title span {
  background: linear-gradient(to right, #111827, #374151, #111827);
  -webkit-background-clip: text;
  background-clip: text;
  color: transparent;
}

.dark .hero-title span {
  background: linear-gradient(to right, #fff, #d1d5db, #fff);
  -webkit-background-clip: text;
  background-clip: text;
  color: transparent;
}

.hero-subtitle {
  font-size: 1.125rem;
  color: #4b5563;
  margin-bottom: 2.5rem;
  max-width: 36rem;
  margin-left: auto;
  margin-right: auto;
}

@media (min-width: 640px) {
  .hero-subtitle {
    font-size: 1.25rem;
  }
}

.dark .hero-subtitle {
  color: #9ca3af;
}

/* --- CTA button --- */
.hero-cta {
  display: inline-flex;
  align-items: center;
  gap: 0.5rem;
  padding: 1rem 2rem;
  font-size: 1rem;
  font-weight: 600;
  border-radius: 0.75rem;
  background: #111827;
  color: #fff;
  box-shadow: 0 10px 15px -3px rgba(0,0,0,0.1), 0 4px 6px -4px rgba(0,0,0,0.1);
  transition: all 0.3s;
}

.hero-cta:hover {
  background: #374151;
  box-shadow: 0 20px 25px -5px rgba(0,0,0,0.1), 0 8px 10px -6px rgba(0,0,0,0.1);
  transform: translateY(-2px);
}

.dark .hero-cta {
  background: #fff;
  color: #111827;
}

.dark .hero-cta:hover {
  background: #e5e7eb;
}

.cta-icon {
  width: 1.25rem;
  height: 1.25rem;
  transition: transform 0.3s;
}

.cta-arrow {
  width: 1rem;
  height: 1rem;
  transition: transform 0.3s;
}

.hero-cta:hover .cta-icon {
  transform: scale(1.1);
}

.hero-cta:hover .cta-arrow {
  transform: translateX(4px);
}

/* --- Scroll indicator --- */
.hero-scroll-hint {
  position: absolute;
  bottom: 2rem;
  left: 50%;
  transform: translateX(-50%);
  z-index: 10;
  animation: hero-fade-in 1s ease-out 1.5s forwards;
}

.scroll-pill {
  width: 1.5rem;
  height: 2.5rem;
  border-radius: 9999px;
  border: 2px solid #9ca3af;
  display: flex;
  justify-content: center;
  padding-top: 0.5rem;
}

.dark .scroll-pill {
  border-color: #4b5563;
}

.scroll-dot {
  width: 0.25rem;
  height: 0.5rem;
  border-radius: 9999px;
  background: #9ca3af;
  animation: bounce 1s infinite;
}

.dark .scroll-dot {
  background: #4b5563;
}

@keyframes bounce {
  0%, 100% { transform: translateY(-25%); animation-timing-function: cubic-bezier(0.8,0,1,1); }
  50% { transform: translateY(0); animation-timing-function: cubic-bezier(0,0,0.2,1); }
}

/* --- Hero entrance animations --- */
@keyframes hero-fade-up {
  from { opacity: 0; transform: translateY(30px); }
  to   { opacity: 1; transform: translateY(0); }
}

@keyframes hero-fade-in {
  from { opacity: 0; }
  to   { opacity: 1; }
}

/* --- SVG gradient colors (light) --- */
.hero-glow-inner  { stop-color: rgba(99, 102, 241, 0.35); }
.hero-glow-outer  { stop-color: rgba(99, 102, 241, 0); }
.hero-glow2-inner { stop-color: rgba(168, 85, 247, 0.30); }
.hero-glow2-outer { stop-color: rgba(168, 85, 247, 0); }

.dark .hero-glow-inner  { stop-color: rgba(99, 102, 241, 0.25); }
.dark .hero-glow-outer  { stop-color: rgba(99, 102, 241, 0); }
.dark .hero-glow2-inner { stop-color: rgba(168, 85, 247, 0.20); }
.dark .hero-glow2-outer { stop-color: rgba(168, 85, 247, 0); }

.hero-grid { color: #94a3b8; }
.dark .hero-grid { color: #475569; }

/* --- Node / particle styles --- */
.hero-node {
  transition: opacity 0.3s;
}

.hero-particle {
  animation: particle-drift linear infinite;
}

@keyframes particle-drift {
  0%   { opacity: 0; transform: translateY(0); }
  10%  { opacity: 1; }
  90%  { opacity: 1; }
  100% { opacity: 0; transform: translateY(-120px); }
}