*, *::before, *::after {
  box-sizing: border-box;
}

html {
  scroll-behavior: smooth;
  scroll-padding-top: 80px;
}

body {
  overflow-x: hidden;
}

/* Scroll animations — progressive enhancement, hidden by default */
.scroll-animate {
  opacity: 1;
  transform: none;
  transition: opacity 0.7s cubic-bezier(0.22, 1, 0.36, 1), transform 0.7s cubic-bezier(0.22, 1, 0.36, 1);
}

@media (prefers-reduced-motion: no-preference) {
  .scroll-animate {
    opacity: 0;
    transform: translateY(30px);
  }
  .scroll-animate.is-visible {
    opacity: 1;
    transform: translateY(0);
  }
}

/* Navbar scroll state */
.navbar-scrolled {
  background: rgba(255, 255, 255, 0.97) !important;
  backdrop-filter: blur(12px);
  box-shadow: 0 1px 20px rgba(0, 0, 0, 0.08);
}

.navbar-scrolled .nav-text {
  color: #334155 !important;
}

.navbar-scrolled .nav-btn .nav-line-top,
.navbar-scrolled .nav-btn .nav-line-mid,
.navbar-scrolled .nav-btn .nav-line-bot {
  background: #334155 !important;
}

/* Mobile menu */
.mobile-menu-open {
  opacity: 1 !important;
  pointer-events: all !important;
}

.mobile-menu-open .mobile-link {
  animation: fadeDown 0.4s cubic-bezier(0.22, 1, 0.36, 1) forwards;
  opacity: 0;
}

.mobile-menu-open .mobile-link:nth-child(1) { animation-delay: 0.05s; }
.mobile-menu-open .mobile-link:nth-child(2) { animation-delay: 0.1s; }
.mobile-menu-open .mobile-link:nth-child(3) { animation-delay: 0.15s; }
.mobile-menu-open .mobile-link:nth-child(4) { animation-delay: 0.2s; }

@keyframes fadeDown {
  from { opacity: 0; transform: translateY(-10px); }
  to { opacity: 1; transform: translateY(0); }
}

/* Hamburger animation */
.menu-btn-active .nav-line-top {
  transform: translateY(7px) rotate(45deg);
}

.menu-btn-active .nav-line-mid {
  opacity: 0;
}

.menu-btn-active .nav-line-bot {
  transform: translateY(-7px) rotate(-45deg);
  width: 1.25rem;
}

/* Selection color */
::selection {
  background: rgba(13, 148, 136, 0.2);
  color: #0f172a;
}

/* Custom scrollbar */
::-webkit-scrollbar {
  width: 8px;
}
::-webkit-scrollbar-track {
  background: #f1f5f9;
}
::-webkit-scrollbar-thumb {
  background: #94a3b8;
  border-radius: 4px;
}
::-webkit-scrollbar-thumb:hover {
  background: #64748b;
}