/* =====================================================================
   ODYSSEY — Shared Design System
   Rovers & Drones Team · K. J. Somaiya School of Engineering
   ===================================================================== */

:root {
  /* Space palette */
  --bg-0: #04050a;          /* deepest space */
  --bg-1: #080a12;          /* base surface */
  --bg-2: #0d1120;          /* raised surface */

  /* Brand accents (from mission imagery) */
  --amber: #f97316;         /* rover trajectory / primary */
  --amber-soft: #fbbf24;
  --cyan: #38bdf8;          /* atmosphere / secondary */
  --teal: #34d399;          /* orbit node */
  --amber-glow: rgba(249, 115, 22, 0.45);
  --cyan-glow: rgba(56, 189, 248, 0.40);

  /* Text */
  --text: #f5f7fb;
  --text-muted: #aeb6c6;
  --text-dim: #6b7488;

  /* Glass */
  --glass-bg: rgba(255, 255, 255, 0.055);
  --glass-bg-strong: rgba(255, 255, 255, 0.09);
  --glass-border: rgba(255, 255, 255, 0.12);
  --glass-highlight: rgba(255, 255, 255, 0.35);

  /* Type */
  --font-ui: 'Outfit', system-ui, -apple-system, sans-serif;
  --font-display: 'Fraunces', 'Times New Roman', serif;

  --nav-h: 72px;
  --ease: cubic-bezier(0.16, 1, 0.3, 1);
  --maxw: 1240px;
}

* { margin: 0; padding: 0; box-sizing: border-box; }
html { scroll-behavior: smooth; -webkit-text-size-adjust: 100%; }

body {
  background-color: var(--bg-0);
  color: var(--text);
  font-family: var(--font-ui);
  line-height: 1.6;
  overflow-x: hidden;
  -webkit-font-smoothing: antialiased;
  text-rendering: optimizeLegibility;
}

::selection { background: var(--amber); color: #0a0a0a; }

::-webkit-scrollbar { width: 9px; }
::-webkit-scrollbar-track { background: var(--bg-0); }
::-webkit-scrollbar-thumb { background: #23283a; border-radius: 5px; }
::-webkit-scrollbar-thumb:hover { background: var(--amber); }

a { color: inherit; text-decoration: none; }
img { display: block; max-width: 100%; }

.container {
  width: 100%;
  max-width: var(--maxw);
  margin: 0 auto;
  padding: 0 28px;
}

.eyebrow {
  display: inline-flex;
  align-items: center;
  gap: 10px;
  font-size: 0.72rem;
  font-weight: 600;
  letter-spacing: 0.28em;
  text-transform: uppercase;
  color: var(--amber);
}
.eyebrow::before {
  content: '';
  width: 22px; height: 1px;
  background: linear-gradient(90deg, transparent, var(--amber));
}

.serif { font-family: var(--font-display); font-weight: 400; font-optical-sizing: auto; }

/* Gradient headline helper */
.grad-text {
  background: linear-gradient(135deg, #ffffff 35%, var(--text-muted) 100%);
  -webkit-background-clip: text; background-clip: text;
  -webkit-text-fill-color: transparent;
}

/* ---------------------------------------------------------------------
   LIQUID GLASS NAVIGATION (Apple-inspired)
   --------------------------------------------------------------------- */
.nav-shell {
  position: fixed;
  top: 18px; left: 0; right: 0;
  z-index: 1000;
  display: flex;
  justify-content: center;
  pointer-events: none;
  padding: 0 20px;
}

.liquid-nav {
  pointer-events: auto;
  display: flex;
  align-items: center;
  gap: 8px;
  width: 100%;
  max-width: 940px;
  height: 76px;
  padding: 0 18px 0 28px;
  border-radius: 999px;
  position: relative;
  isolation: isolate;

  background: rgba(255, 255, 255, 0.06);
  border: 1px solid var(--glass-border);
  -webkit-backdrop-filter: blur(22px) saturate(180%);
  backdrop-filter: blur(22px) saturate(180%);
  box-shadow:
    0 8px 32px rgba(0, 0, 0, 0.45),
    inset 0 1px 0 var(--glass-highlight),
    inset 0 -1px 1px rgba(255, 255, 255, 0.06);
  transition: box-shadow 0.5s var(--ease), background 0.5s var(--ease), transform 0.4s var(--ease);
}

/* Specular sheen sweeping across the glass */
.liquid-nav::before {
  content: '';
  position: absolute;
  inset: 0;
  border-radius: inherit;
  padding: 1px;
  background: linear-gradient(
    130deg,
    rgba(255, 255, 255, 0.5) 0%,
    rgba(255, 255, 255, 0.05) 22%,
    transparent 45%,
    transparent 70%,
    rgba(255, 255, 255, 0.18) 100%);
  -webkit-mask: linear-gradient(#000 0 0) content-box, linear-gradient(#000 0 0);
  -webkit-mask-composite: xor;
          mask-composite: exclude;
  pointer-events: none;
  z-index: 2;
}

/* Soft top light bloom inside the glass */
.liquid-nav::after {
  content: '';
  position: absolute;
  top: 0; left: 12%; right: 12%;
  height: 55%;
  border-radius: 999px;
  background: radial-gradient(ellipse at top, rgba(255,255,255,0.14), transparent 72%);
  pointer-events: none;
  z-index: 1;
}

.liquid-nav.scrolled {
  background: rgba(10, 12, 20, 0.55);
  box-shadow:
    0 10px 40px rgba(0, 0, 0, 0.6),
    inset 0 1px 0 rgba(255, 255, 255, 0.25);
}

.nav-brand {
  display: flex;
  align-items: center;
  gap: 16px;
  z-index: 3;
  margin-right: auto;
  white-space: nowrap;
}
.nav-logo {
  height: 56px;
  width: auto;
  object-fit: contain;
  display: block;
}
.nav-trust-logo {
  height: 46px;
  width: auto;
  object-fit: contain;
  display: block;
}
.nav-somaiya-logo {
  height: 38px;
  width: auto;
  object-fit: contain;
  display: block;
}
.nav-brand-divider {
  width: 1px;
  height: 30px;
  background: rgba(255, 255, 255, 0.18);
  flex-shrink: 0;
}

.nav-links {
  display: flex;
  align-items: center;
  gap: 2px;
  z-index: 3;
}
.nav-links a {
  position: relative;
  padding: 9px 16px;
  border-radius: 999px;
  font-size: 0.82rem;
  font-weight: 500;
  letter-spacing: 0.02em;
  color: var(--text-muted);
  transition: color 0.25s var(--ease), background 0.25s var(--ease);
  white-space: nowrap;
}
.nav-links a:hover { color: #fff; background: rgba(255,255,255,0.08); }
.nav-links a.active {
  color: #fff;
  background: rgba(255,255,255,0.1);
  box-shadow: inset 0 1px 0 rgba(255,255,255,0.25);
}

.nav-cta {
  z-index: 3;
  display: inline-flex;
  align-items: center;
  gap: 7px;
  padding: 10px 20px;
  border-radius: 999px;
  font-size: 0.8rem;
  font-weight: 600;
  color: #0a0a0a;
  background: linear-gradient(135deg, #fff, #d8dde8);
  box-shadow: 0 4px 14px rgba(255,255,255,0.18), inset 0 1px 0 #fff;
  transition: transform 0.3s var(--ease), box-shadow 0.3s var(--ease);
  white-space: nowrap;
}
.nav-cta:hover {
  transform: translateY(-1px);
  box-shadow: 0 6px 22px var(--amber-glow), inset 0 1px 0 #fff;
}

/* Mobile hamburger */
.nav-toggle {
  display: none;
  z-index: 3;
  width: 42px; height: 42px;
  border: none;
  border-radius: 50%;
  background: rgba(255,255,255,0.08);
  cursor: pointer;
  position: relative;
}
.nav-toggle span {
  position: absolute; left: 11px; right: 11px; height: 2px;
  background: #fff; border-radius: 2px; transition: 0.3s var(--ease);
}
.nav-toggle span:nth-child(1) { top: 15px; }
.nav-toggle span:nth-child(2) { top: 21px; }
.nav-toggle span:nth-child(3) { top: 27px; }
.nav-toggle.open span:nth-child(1) { top: 21px; transform: rotate(45deg); }
.nav-toggle.open span:nth-child(2) { opacity: 0; }
.nav-toggle.open span:nth-child(3) { top: 21px; transform: rotate(-45deg); }

/* ---------------------------------------------------------------------
   Buttons
   --------------------------------------------------------------------- */
.btn {
  display: inline-flex;
  align-items: center;
  gap: 9px;
  padding: 14px 28px;
  border-radius: 999px;
  font-family: var(--font-ui);
  font-size: 0.88rem;
  font-weight: 600;
  letter-spacing: 0.01em;
  cursor: pointer;
  border: 1px solid transparent;
  transition: all 0.35s var(--ease);
}
.btn-primary {
  color: #0a0a0a;
  background: linear-gradient(135deg, var(--amber-soft), var(--amber));
  box-shadow: 0 8px 26px var(--amber-glow), inset 0 1px 0 rgba(255,255,255,0.4);
}
.btn-primary:hover { transform: translateY(-2px); box-shadow: 0 12px 34px var(--amber-glow); }
.btn-ghost {
  color: var(--text);
  background: var(--glass-bg);
  border-color: var(--glass-border);
  -webkit-backdrop-filter: blur(10px); backdrop-filter: blur(10px);
}
.btn-ghost:hover { background: var(--glass-bg-strong); border-color: rgba(255,255,255,0.28); transform: translateY(-2px); }

/* ---------------------------------------------------------------------
   Footer
   --------------------------------------------------------------------- */
.site-footer {
  position: relative;
  background: linear-gradient(180deg, transparent, #020308 40%);
  border-top: 1px solid var(--glass-border);
  padding: 84px 0 0;
  z-index: 5;
}
.footer-grid {
  display: grid;
  grid-template-columns: 1.6fr repeat(3, 1fr);
  gap: 48px;
  padding-bottom: 56px;
}
.footer-brand .footer-logo {
  font-size: 1.5rem; font-weight: 800; letter-spacing: 0.28em;
  display: inline-flex; align-items: center; gap: 10px;
}
.footer-brand .footer-logo .dot {
  width: 9px; height: 9px; border-radius: 50%; background: var(--amber);
  box-shadow: 0 0 12px var(--amber);
}
.footer-brand p { color: var(--text-muted); font-size: 0.9rem; max-width: 300px; margin-top: 18px; }
.footer-col h4 {
  font-size: 0.74rem; text-transform: uppercase; letter-spacing: 0.16em;
  color: #fff; margin-bottom: 18px; font-weight: 600;
}
.footer-col a {
  display: block; font-size: 0.88rem; color: var(--text-dim);
  margin-bottom: 12px; transition: color 0.25s, padding-left 0.25s;
}
.footer-col a:hover { color: var(--cyan); padding-left: 5px; }
.footer-bottom {
  border-top: 1px solid rgba(255,255,255,0.06);
  padding: 26px 0;
  text-align: center;
}
.footer-bottom p { font-size: 0.8rem; color: var(--text-dim); }

/* ---------------------------------------------------------------------
   Reveal-on-scroll utility
   --------------------------------------------------------------------- */
.reveal { opacity: 0; transform: translateY(34px); transition: opacity 0.9s var(--ease), transform 0.9s var(--ease); }
.reveal.in { opacity: 1; transform: none; }

/* Ambient starfield background (shared) */
.starfield {
  position: fixed; inset: 0; z-index: -2;
  background:
    radial-gradient(1200px 700px at 80% -10%, rgba(56,189,248,0.10), transparent 60%),
    radial-gradient(900px 600px at 10% 110%, rgba(249,115,22,0.09), transparent 60%),
    var(--bg-0);
}
.starfield::after {
  content: ''; position: absolute; inset: 0;
  background-image:
    radial-gradient(1px 1px at 20% 30%, #fff, transparent),
    radial-gradient(1px 1px at 70% 60%, rgba(255,255,255,0.7), transparent),
    radial-gradient(1px 1px at 40% 80%, rgba(255,255,255,0.6), transparent),
    radial-gradient(1.5px 1.5px at 85% 25%, #fff, transparent),
    radial-gradient(1px 1px at 55% 15%, rgba(255,255,255,0.6), transparent),
    radial-gradient(1px 1px at 15% 65%, rgba(255,255,255,0.5), transparent);
  background-size: 100% 100%;
  opacity: 0.5;
}

/* ---------------------------------------------------------------------
   Responsive
   --------------------------------------------------------------------- */
@media (max-width: 860px) {
  .nav-links, .nav-cta { display: none; }
  .nav-toggle { display: block; }
  
  .nav-shell {
    top: 0;
    left: 0;
    right: 0;
    padding: 0;
  }
  
  .liquid-nav {
    height: 66px;
    width: 100%;
    max-width: 100%;
    border-radius: 0;
    border-left: none;
    border-right: none;
    border-top: none;
    padding: 0 16px 0 24px;
  }

  .nav-logo { height: 48px; }
  .nav-trust-logo { height: 40px; }
  .nav-somaiya-logo { height: 32px; }
  .nav-brand-divider { height: 24px; }
  .nav-brand { gap: 12px; }

  .mobile-menu {
    top: 74px;
    left: 12px;
    right: 12px;
    border-radius: 16px;
  }

  .nav-shell.open .mobile-menu { opacity: 1; visibility: visible; transform: translateY(0); }

  .footer-grid { grid-template-columns: 1fr 1fr; gap: 32px; }
}
@media (max-width: 480px) {
  .liquid-nav {
    height: 58px;
    padding: 0 12px 0 16px;
  }
  
  .mobile-menu {
    top: 66px;
    left: 8px;
    right: 8px;
    border-radius: 12px;
  }

  .nav-logo { height: 36px; }
  .nav-trust-logo { height: 30px; }
  .nav-somaiya-logo { height: 24px; }
  .nav-brand-divider { height: 18px; }
  .nav-brand { gap: 8px; }
  .footer-grid { grid-template-columns: 1fr; }
  .container { padding: 0 20px; }
}

/* Mobile slide-down menu */
.mobile-menu {
  position: fixed;
  top: 90px; left: 20px; right: 20px;
  z-index: 999;
  pointer-events: auto;
  padding: 14px;
  border-radius: 24px;
  background: rgba(10, 12, 20, 0.7);
  border: 1px solid var(--glass-border);
  -webkit-backdrop-filter: blur(22px) saturate(180%);
  backdrop-filter: blur(22px) saturate(180%);
  box-shadow: 0 20px 50px rgba(0,0,0,0.6), inset 0 1px 0 rgba(255,255,255,0.2);
  opacity: 0; visibility: hidden; transform: translateY(-14px);
  transition: all 0.4s var(--ease);
}
.mobile-menu a {
  display: block; padding: 14px 18px; border-radius: 14px;
  font-size: 1rem; font-weight: 500; color: var(--text-muted);
}
.mobile-menu a:hover, .mobile-menu a.active { color: #fff; background: rgba(255,255,255,0.08); }
.mobile-menu .btn { width: 100%; justify-content: center; margin-top: 8px; }
@media (min-width: 861px) { .mobile-menu { display: none; } }

@media (prefers-reduced-motion: reduce) {
  * { animation-duration: 0.01ms !important; transition-duration: 0.01ms !important; scroll-behavior: auto !important; }
  .reveal { opacity: 1; transform: none; }
}