:root {
  --navy-900: #0b1f3a;
  --navy-800: #0f2a4a;
  --blue-600: #0077b6;
  --teal-500: #00b4d8;
  --ease: cubic-bezier(.4, 0, .2, 1);
}
body {
  font-family: 'Inter', sans-serif;
}
.font-display {
  font-family: 'Plus Jakarta Sans', sans-serif;
}
/* Primary Button Gradients & Shadows */
.btn-primary {
  background: linear-gradient(90deg, var(--blue-600), var(--teal-500));
  color: #fff;
  transition: transform .25s var(--ease), box-shadow .25s var(--ease), filter .2s var(--ease);
}
.btn-primary:hover {
  transform: translateY(-2px);
  box-shadow: 0 14px 24px -8px rgba(0, 180, 216, .45);
  filter: brightness(1.04);
}
.btn-primary:active {
  transform: translateY(0) scale(.98);
}
/* Backgrounds */
.hero-bg {
  background:
    radial-gradient(640px 480px at 8% 0%, rgba(0, 180, 216, .10), transparent 60%),
    radial-gradient(560px 420px at 96% 30%, rgba(18, 150, 109, .08), transparent 60%),
    linear-gradient(160deg, #eef7fb 0%, #eaf7f2 55%, #f2f8fb 100%);
}
.donut {
  background: conic-gradient(var(--teal-500) 0% 65%, var(--navy-800) 65% 100%);
  border-radius: 9999px;
}
/* Feature Cards Hover Interaction */
.card-hover {
  transition: transform .3s var(--ease), box-shadow .3s var(--ease), border-color .3s var(--ease);
}
.card-hover:hover {
  transform: translateY(-8px);
  box-shadow: 0 24px 40px -12px rgba(11, 31, 58, .12);
}
/* Floating Animation for Hero Mockup */
@media (prefers-reduced-motion: no-preference) {
  .float-anim { animation: floaty 6s ease-in-out infinite; }
}
@keyframes floaty {
  0%, 100% { transform: translateY(0); }
  50% { transform: translateY(-12px); }
}
/* Sticky Navigation Surface Transition */
#siteNav {
  transition: background-color .3s var(--ease), box-shadow .3s var(--ease), backdrop-filter .3s var(--ease);
}
#siteNav.scrolled {
  background: rgba(255, 255, 255, .9);
  backdrop-filter: blur(12px);
  box-shadow: 0 10px 30px -10px rgba(11, 31, 58, .15);
}
/* Animated Underline for Nav Links */
.nav-link { position: relative; }
.nav-link::after {
  content: "";
  position: absolute;
  left: 0;
  right: 0;
  bottom: -6px;
  height: 2px;
  border-radius: 2px;
  background: linear-gradient(90deg, var(--blue-600), var(--teal-500));
  transform: scaleX(0);
  transform-origin: left;
  transition: transform .25s var(--ease);
}
.nav-link:hover::after, .nav-link.active::after {
  transform: scaleX(1);
}
/* Mobile Menu Expansion */
#mobileMenu {
  max-height: 0;
  overflow: hidden;
  transition: max-height .35s var(--ease);
}
#mobileMenu.open {
  max-height: 420px;
}
/* Scroll-Reveal Micro Interaction */
.reveal {
  opacity: 0;
  transform: translateY(24px);
  transition: opacity .7s var(--ease), transform .7s var(--ease);
}
.reveal.is-visible {
  opacity: 1;
  transform: translateY(0);
}
@media (prefers-reduced-motion: reduce) {
  .reveal { opacity: 1; transform: none; transition: none; }
  .float-anim { animation: none; }
}
/* FAQ Accordion Native Details Marker Reset and Animation */
details > summary {
  list-style: none;
  cursor: pointer;
}
details > summary::-webkit-details-marker {
  display: none;
}
details[open] .faq-chevron {
  transform: rotate(180deg);
}
.faq-chevron {
  transition: transform .3s var(--ease);
}
/* Working steps gradient line */
.step-line {
  background: linear-gradient(90deg, var(--teal-500) 0%, rgba(0, 180, 216, .10) 100%);
}