/* Base */
* { box-sizing: border-box; }
html, body { height: 100%; }
body {
  margin: 0;
  font-family: ui-sans-serif, system-ui, -apple-system, Segoe UI, Roboto, Ubuntu, Cantarell, "Helvetica Neue", Arial, sans-serif;
  color: #e9eef7;
  background: #0a0f1a;
  line-height: 1.5;
}

/* Background layer */
.bg {
  position: fixed;
  inset: 0;
  background-color: #0a0f1a; /* base tone */
  background-position: center;
  background-repeat: no-repeat;
  background-size: cover;
  filter: saturate(1) brightness(0.9);
  z-index: -1;
}

/* Hero image slots — just upload files to these exact paths */
.bg.hero-home           { background-image: url("/assets/images/bg/hero-home.webp"); }
.bg.hero-mathematics    { background-image: url("/assets/images/bg/hero-mathematics.webp"); }
.bg.hero-biodome        { background-image: url("/assets/images/bg/hero-biodome.webp"); }
.bg.hero-gundam         { background-image: url("/assets/images/bg/hero-gundam.jpg"); } /* or .jpg if you prefer */
.bg.hero-infrastructure { background-image: url("/assets/images/bg/hero-infrastructure.webp"); }
.bg.hero-poetry         { background-image: url("/assets/images/bg/hero-poetry.webp"); }
.bg.hero-resume         { background-image: url("/assets/images/bg/hero-resume.webp"); }
.bg.hero-events         { background-image: url("/assets/images/bg/hero-events.webp"); }
.bg.hero-shop           { background-image: url("/assets/images/bg/hero-shop.webp"); }
.bg.hero-links          { background-image: url("/assets/images/bg/hero-links.webp"); }

/* Header / Nav */
.site-header {
  position: fixed; top: 0; left: 0; right: 0;
  display: flex; align-items: center;
  gap: 10px;
  padding: 12px 14px;
  backdrop-filter: blur(6px);
  background: rgba(10,15,26,0.35);
  border-bottom: 1px solid rgba(255,255,255,0.08);
  z-index: 1000;
}
.menu-toggle {
  font-size: 20px; line-height: 1;
  padding: 6px 10px;
  color: #cfe3ff;
  background: transparent;
  border: 1px solid rgba(255,255,255,0.18);
  border-radius: 8px;
}
.nav { display: flex; gap: 18px; align-items: center; }
.nav .brand { font-weight: 700; letter-spacing: 0.06em; text-decoration: none; color: #e9eef7; }
.nav ul { display: flex; gap: 14px; padding: 0; margin: 0; list-style: none; }
.nav a { color: #cfe3ff; text-decoration: none; }
.nav a:hover { text-decoration: underline; }

/* Mobile nav */
@media (max-width: 780px) {
  .nav ul { display: none; }
  .nav.open ul {
    display: flex;
    position: absolute; top: 48px; left: 12px; right: 12px;
    flex-direction: column;
    background: rgba(10,15,26,0.9);
    padding: 12px; border-radius: 10px;
    border: 1px solid rgba(255,255,255,0.08);
  }
}

/* Sections */
.section {
  padding: 100px 24px 72px;
  min-height: 75vh;
  background: linear-gradient(to bottom, rgba(10,15,26,0.0), rgba(10,15,26,0.38));
  border-top: 1px solid rgba(255,255,255,0.06);
}
.hero {
  display: grid; place-content: center; text-align: center; gap: 10px;
  min-height: 90vh; padding-top: 120px;
  background: radial-gradient(40% 40% at 50% 30%, rgba(255,255,255,0.08), transparent);
}
.hero h1 { margin: 0 0 6px; font-size: clamp(36px, 6vw, 64px); letter-spacing: 0.02em; }
.tag { opacity: 0.9; font-size: clamp(16px, 2.6vw, 20px); }

/* Buttons */
.btn {
  margin-top: 16px; padding: 10px 14px;
  border-radius: 10px; border: 1px solid rgba(255,255,255,0.16);
  background: rgba(255,255,255,0.06); color: #e9eef7;
}
.btn:hover { background: rgba(255,255,255,0.12); }

/* Portal hotspot (adjust % to land over your lighthouse) */
.hotspot {
  position: absolute;
  left: 60%; top: 52%;
  width: clamp(60px, 10vw, 120px);
  aspect-ratio: 1 / 1;
  background: rgba(255,255,255,0.06);
  border: 1px dashed rgba(255,255,255,0.25);
  border-radius: 50%;
  backdrop-filter: blur(2px);
  transition: transform 0.2s ease, background 0.2s ease;
}
.hotspot:hover { transform: scale(1.04); background: rgba(255,255,255,0.12); }

/* Footer */
.site-footer {
  padding: 28px 24px; text-align: center; opacity: 0.8;
  border-top: 1px solid rgba(255,255,255,0.08);
  background: rgba(10,15,26,0.45);
}