body {
  font-family: system-ui, -apple-system, "Segoe UI", Roboto, "Helvetica Neue", Arial, sans-serif;
  color: #1f2933;
  background-color: #ffffff;
}

/* Navbar */
.navbar-main {
  position: fixed;
  top: 1.5rem;
  left: 50%;
  transform: translateX(-50%);
  width: min(calc(100% - 1.5rem), 1280px);
  padding: 0.85rem 1.5rem;
  border-radius: 999px;
  background-color: transparent;
  backdrop-filter: none;
  box-shadow: none;
  transition: background-color 0.25s ease, box-shadow 0.25s ease, backdrop-filter 0.25s ease;
  z-index: 1050;
}

.navbar-main .navbar-brand,
.navbar-main .nav-link {
  color: #1f2933;
}

.navbar-main .navbar-toggler {
  border-color: rgba(31, 41, 51, 0.35);
}

.navbar-main .navbar-toggler-icon {
  filter: invert(18%) sepia(12%) saturate(664%) hue-rotate(178deg) brightness(94%) contrast(86%);
}

.navbar-main .nav-link {
  font-weight: 500;
  margin-left: 0.5rem;
}

.navbar-main .nav-link:hover,
.navbar-main .nav-link:focus {
  color: #0d6efd;
}

.navbar-main .navbar-logo {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  width: 34px;
  height: 34px;
  border-radius: 50%;
  background-color: #0d6efd;
  color: #ffffff;
  font-weight: 700;
  font-size: 0.9rem;
  letter-spacing: 0.04em;
}

.navbar-main.navbar-scrolled {
  background-color: rgba(248, 249, 250, 0.78);
  backdrop-filter: blur(14px);
  box-shadow: 0 18px 48px rgba(15, 23, 42, 0.005);
}

/* Hero */
.hero-section {
  min-height: 100vh;
  position: relative;
  padding-top: 6rem;
  padding-bottom: 6rem;
  background-image: url("../img/frontpage.jpg");
  background-size: cover;
  background-position: center;
  background-repeat: no-repeat;
}

.hero-overlay {
  position: absolute;
  inset: 0;
  background: linear-gradient(135deg, rgba(15, 23, 42, 0.78), rgba(18, 90, 157, 0.55));
}

.hero-section .lead {
  color: rgba(255, 255, 255, 0.88);
}

.hero-link {
  color: #f8fafc;
  text-decoration: none;
  transition: color 0.2s ease;
}

.hero-link:hover,
.hero-link:focus-visible {
  color: #2c78eb;
}



/* Sections */
section {
  border-top: 1px solid #e5e7eb;
}

section:first-of-type {
  border-top: none;
}

/* Back-to-top button */
.back-to-top {
  position: fixed;
  right: 1.75rem;
  bottom: 1.75rem;
  font-size: 2.6rem;            /* icon size */
  color: #0d6efd;               /* blue accent for the icon */
  text-decoration: none;
  opacity: 0;
  pointer-events: none;
  transform: translateY(12px);
  transition: opacity 0.25s ease, transform 0.25s ease;
  z-index: 1040;
}

.back-to-top:hover,
.back-to-top:focus-visible {
  color: #0b5ed7;
}

.back-to-top--visible {
  opacity: 1;
  pointer-events: auto;
  transform: translateY(0);
}