:root {
  /* HEALTH Theme Colors (Clean, Fresh, Blues) */
  --optiv-bg: #f4fbfd;
  --optiv-surface: #ffffff;
  --optiv-tone: #0077b6;
  --optiv-tone-hover: #023e8a;
  --optiv-ink: #2b2d42;
  --optiv-gradient: linear-gradient(135deg, #0077b6, #00b4d8);
  
  /* Fonts */
  --font-display: 'Bebas Neue', sans-serif;
  --font-body: 'Inter', sans-serif;
  
  /* Selected Randoms */
  --optiv-radius: 16px; /* soft */
  --optiv-shadow: 0 4px 6px -1px rgba(0,0,0,0.1), 0 2px 4px -1px rgba(0,0,0,0.06); /* raised */
}

/* Global Setup */
* {
  margin: 0;
  padding: 0;
  box-sizing: border-box;
}

body {
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
}

/* Typography & Case Rules */
.optiv-primary-heading, 
.optiv-secondary-heading, 
.optiv-brand-label,
.optiv-purchase-trigger {
  text-transform: uppercase;
  letter-spacing: 0.05em;
}

/* Preset A Specifics */
.optiv-top-masthead {
  border-bottom: 4px solid var(--optiv-tone);
}

.optiv-purchase-trigger {
  border-radius: 999px; /* pill */
}

.optiv-purchase-trigger:hover {
  transform: translateY(-2px);
  box-shadow: 0 10px 15px -3px rgba(0,0,0,0.15), 0 4px 6px -2px rgba(0,0,0,0.05); /* hover shadow */
  background: var(--optiv-tone-hover);
}

.optiv-buyer-note {
  border-left: 4px solid var(--optiv-tone);
}

/* Gallery CSS Logic */
.optiv-frame {
  opacity: 0;
  pointer-events: none;
  transition: opacity 0.3s ease-in-out;
  z-index: 1;
}

#pic1:checked ~ .optiv-main-stage .optiv-f1,
#pic2:checked ~ .optiv-main-stage .optiv-f2,
#pic3:checked ~ .optiv-main-stage .optiv-f3,
#pic4:checked ~ .optiv-main-stage .optiv-f4 {
  opacity: 1;
  pointer-events: auto;
  z-index: 2;
}

/* Thumbnails Active State */
#pic1:checked ~ .optiv-thumb-strip label[for="pic1"],
#pic2:checked ~ .optiv-thumb-strip label[for="pic2"],
#pic3:checked ~ .optiv-thumb-strip label[for="pic3"],
#pic4:checked ~ .optiv-thumb-strip label[for="pic4"] {
  border-color: var(--optiv-tone);
  opacity: 1;
}

.optiv-thumb-node {
  opacity: 0.6;
  transition: all 0.2s ease;
}

.optiv-thumb-node:hover {
  opacity: 1;
}