/* ---------- Global page background ---------- */
:root{
  --bg-image: url("IMG_20250227_155733473_HDR.jpg");
}

body{
  font-family: Arial, sans-serif;
  margin: 0;
  padding: 0;
  background-image: var(--bg-image);
  background-size: cover;
  background-position: center;
  background-repeat: no-repeat;
  background-attachment: fixed;
  position: relative;
}

body::before{
  content: "";
  position: fixed;
  top: 0; left: 0;
  width: 100%; height: 100%;
  background: rgba(0,0,0,0.45);
  z-index: -1;
}

/* ---------- Header ---------- */
.site-header{
  background:
    linear-gradient(
      rgba(0,0,0,0.65),
      rgba(0,0,0,0.65)
    ),
    url("nozzle.jpg");
  background-size: cover;
  background-position: center;
  background-repeat: no-repeat;

  color: white;
  padding: 28px 20px;
  text-align: center;
}

/* ---------- Layout ---------- */
.layout{
  max-width: 1200px;
  margin: 40px auto;
  padding: 0 16px;
  display: grid;
  grid-template-columns: 240px 1fr;
  gap: 18px;
  align-items: start;
}

/* ---------- Sidebar (desktop) ---------- */
.sidebar{
  background: rgba(0,0,0,0.78);
  color: white;
  border-radius: 8px;
  padding: 18px 14px;
  box-shadow: 0 2px 15px rgba(0,0,0,0.25);
  position: sticky;
  top: 18px;
}

.sidebar h2{
  margin: 0 0 12px 0;
  font-size: 1.05rem;
  font-weight: 700;
}

.nav a{
  display: block;
  padding: 10px 10px;
  margin: 6px 0;
  border-radius: 6px;
  text-decoration: none;
  color: white;
  background: rgba(255,255,255,0.10);
  border: 1px solid rgba(255,255,255,0.12);
}

.nav a:hover{ background: rgba(255,255,255,0.16); }

.nav a.active{
  background: rgba(78, 161, 255, 0.20);
  border-color: rgba(78, 161, 255, 0.45);
}

/* ---------- Main container/card ---------- */
.container{
  background: rgba(255,255,255,0.96);
  padding: 25px;
  border-radius: 8px;
  box-shadow: 0 2px 15px rgba(0,0,0,0.25);
}

a{ color: #0066cc; }

/* ---------- Mobile navigation drawer ---------- */
.nav-toggle{
  display: none; /* only visible on mobile */
  position: fixed;
  top: 12px;
  right: 12px;
  z-index: 9999;
  border: 1px solid rgba(255,255,255,0.25);
  background: rgba(0,0,0,0.75);
  color: white;
  padding: 10px 12px;
  border-radius: 10px;
  font-size: 18px;
  cursor: pointer;
}

/* overlay backdrop */
.nav-backdrop{
  display: none;
  position: fixed;
  inset: 0;
  background: rgba(0,0,0,0.45);
  z-index: 1400;
}

/* ---------- Mobile breakpoint ---------- */
@media (max-width: 900px){
  .layout{
    grid-template-columns: 1fr;
    margin: 18px auto;
  }

  /* show hamburger */
  .nav-toggle{
    display: block;
  }

  /* turn sidebar into off-canvas drawer */
  .sidebar{
    position: fixed;
    top: 0;
    left: 0;
    height: 100vh;
    width: min(320px, 85vw);
    border-radius: 0;
    transform: translateX(-105%);
    transition: transform 180ms ease;
    z-index: 1500;
    overflow-y: auto;
    padding-top: 70px; /* space for hamburger */
  }

  /* open state */
  body.nav-open .sidebar{
    transform: translateX(0);
  }

  body.nav-open .nav-backdrop{
    display: block;
  }
}

/* ---------- Mobile bottom nav ---------- */
#mobile-nav{
  display: none;
}

@media (max-width: 900px){
  #mobile-nav{
    display: block;
    margin: 30px 16px 20px;
  }

  #mobile-nav .sidebar{
    position: static;
    transform: none !important;
    width: 100%;
    height: auto;
    border-radius: 8px;
    padding: 14px;
  }

  /* Hide the "Navigation" heading in footer version */
  #mobile-nav .sidebar h2{
    display: none;
  }
}

.site-header {
    background: rgba(0, 0, 0, 0.85);
    color: white;
    padding: 24px 20px;
    text-align: center;
}

.site-header h1 {
    margin: 0 0 6px 0;
}

.site-header p {
    margin: 6px 0;
}

.site-header .disciplines {
    font-size: 0.95em;
    opacity: 0.9;
}

.external-links {
    margin-top: 10px;
    font-size: 0.9em;
}

.external-links a {
    color: #9fd0ff;
    text-decoration: none;
    margin: 0 6px;
}

.external-links a:hover {
    text-decoration: underline;
}

.external-links span {
    opacity: 0.6;
}