/* =============================================================================
   main.css — Global styles, CSS custom properties, layout, typography
   Oakopal Observatory
   ============================================================================= */

/* ─── Custom Properties ─────────────────────────────────────────────────────── */
:root {
  /* Colour palette */
  --color-bg:           #0a0a0f;
  --color-bg-card:      #0d1b2a;
  --color-bg-card-alt:  #111827;
  --color-border:       #1e2d3d;
  --color-border-glow:  #00b4d840;
  --color-accent:       #00b4d8;
  --color-accent-dim:   #0077a8;
  --color-accent-glow:  #00b4d820;
  --color-text:         #e8eaf0;
  --color-text-muted:   #8899aa;
  --color-text-dim:     #556677;
  --color-success:      #22c55e;
  --color-warning:      #f59e0b;
  --color-error:        #ef4444;
  --color-placeholder:  #1a2a3a;

  /* Typography */
  --font-heading:  "Space Grotesk", system-ui, sans-serif;
  --font-body:     "Inter", system-ui, sans-serif;
  --font-mono:     "JetBrains Mono", "Fira Code", monospace;

  /* Spacing scale */
  --space-1:  0.25rem;
  --space-2:  0.5rem;
  --space-3:  0.75rem;
  --space-4:  1rem;
  --space-5:  1.25rem;
  --space-6:  1.5rem;
  --space-8:  2rem;
  --space-10: 2.5rem;
  --space-12: 3rem;
  --space-16: 4rem;
  --space-20: 5rem;

  /* Border radius */
  --radius-sm:  4px;
  --radius-md:  8px;
  --radius-lg:  12px;
  --radius-xl:  16px;
  --radius-full: 9999px;

  /* Shadows */
  --shadow-card: 0 4px 24px rgba(0, 0, 0, 0.5);
  --shadow-glow: 0 0 24px rgba(0, 180, 216, 0.15);

  /* Transitions */
  --transition-fast:   150ms ease;
  --transition-normal: 250ms ease;

  /* Nav height (used for scroll offset) */
  --nav-height: 60px;

  /* Max content width */
  --max-width: 1200px;
}

/* ─── Reset ──────────────────────────────────────────────────────────────────── */
*, *::before, *::after {
  box-sizing: border-box;
  margin: 0;
  padding: 0;
}

html {
  scroll-behavior: smooth;
  scroll-padding-top: var(--nav-height);
  font-size: 16px;
  -webkit-text-size-adjust: 100%;
}

body {
  background-color: var(--color-bg);
  color: var(--color-text);
  font-family: var(--font-body);
  font-size: 1rem;
  line-height: 1.6;
  min-height: 100vh;
  overflow-x: hidden;
}

img, video {
  display: block;
  max-width: 100%;
  height: auto;
}

a {
  color: var(--color-accent);
  text-decoration: none;
  transition: color var(--transition-fast);
}

a:hover,
a:focus-visible {
  color: #fff;
  text-decoration: underline;
}

ul, ol {
  list-style: none;
}

button {
  cursor: pointer;
  font-family: inherit;
}

/* ─── Typography ─────────────────────────────────────────────────────────────── */
h1, h2, h3, h4, h5 {
  font-family: var(--font-heading);
  font-weight: 600;
  line-height: 1.2;
  color: var(--color-text);
}

h1 { font-size: clamp(1.75rem, 5vw, 2.75rem); }
h2 { font-size: clamp(1.4rem,  4vw, 2rem);    }
h3 { font-size: clamp(1.1rem,  3vw, 1.4rem);  }
h4 { font-size: 1.1rem; }

p {
  color: var(--color-text-muted);
  max-width: 65ch;
}

/* ─── Layout utilities ───────────────────────────────────────────────────────── */
.container {
  width: 100%;
  max-width: var(--max-width);
  margin-inline: auto;
  padding-inline: var(--space-6);
}

.section {
  padding-block: var(--space-16);
}

.section-header {
  margin-bottom: var(--space-10);
}

.section-header h2 {
  display: flex;
  align-items: center;
  gap: var(--space-3);
  margin-bottom: var(--space-2);
}

.section-header p {
  color: var(--color-text-muted);
  font-size: 0.95rem;
}

.section-icon {
  width: 28px;
  height: 28px;
  color: var(--color-accent);
  flex-shrink: 0;
}

/* Grid layouts */
.grid-2 {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: var(--space-6);
}

.grid-3 {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: var(--space-6);
}

.grid-auto {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(280px, 1fr));
  gap: var(--space-6);
}

/* ─── Navigation ─────────────────────────────────────────────────────────────── */
.site-nav {
  position: sticky;
  top: 0;
  z-index: 100;
  height: var(--nav-height);
  background-color: rgba(10, 10, 15, 0.92);
  backdrop-filter: blur(12px);
  -webkit-backdrop-filter: blur(12px);
  border-bottom: 1px solid var(--color-border);
}

.nav-inner {
  display: flex;
  align-items: center;
  justify-content: space-between;
  height: 100%;
}

.nav-logo {
  display: flex;
  align-items: center;
  gap: var(--space-3);
  font-family: var(--font-heading);
  font-weight: 700;
  font-size: 1.1rem;
  color: var(--color-text);
  text-decoration: none;
}

.nav-logo:hover { color: var(--color-accent); text-decoration: none; }

.nav-logo-icon {
  width: 32px;
  height: 32px;
  color: var(--color-accent);
}

.nav-links {
  display: flex;
  align-items: center;
  gap: var(--space-1);
}

.nav-links a {
  padding: var(--space-2) var(--space-3);
  border-radius: var(--radius-sm);
  font-size: 0.875rem;
  font-weight: 500;
  color: var(--color-text-muted);
  transition: color var(--transition-fast), background-color var(--transition-fast);
  white-space: nowrap;
}

.nav-links a:hover,
.nav-links a:focus-visible {
  color: var(--color-text);
  background-color: var(--color-bg-card);
  text-decoration: none;
}

.nav-links a.active {
  color: var(--color-accent);
}

/* Hamburger button */
.nav-toggle {
  display: none;
  flex-direction: column;
  justify-content: center;
  align-items: center;
  gap: 5px;
  width: 40px;
  height: 40px;
  background: none;
  border: 1px solid var(--color-border);
  border-radius: var(--radius-sm);
  padding: var(--space-2);
}

.nav-toggle span {
  display: block;
  width: 20px;
  height: 2px;
  background-color: var(--color-text-muted);
  border-radius: var(--radius-full);
  transition: transform var(--transition-normal), opacity var(--transition-normal);
}

.nav-toggle[aria-expanded="true"] span:nth-child(1) {
  transform: translateY(7px) rotate(45deg);
}
.nav-toggle[aria-expanded="true"] span:nth-child(2) {
  opacity: 0;
}
.nav-toggle[aria-expanded="true"] span:nth-child(3) {
  transform: translateY(-7px) rotate(-45deg);
}

/* Mobile nav menu */
.nav-menu {
  display: none;
  position: absolute;
  top: var(--nav-height);
  left: 0;
  right: 0;
  background-color: rgba(10, 10, 15, 0.97);
  border-bottom: 1px solid var(--color-border);
  padding: var(--space-4) var(--space-6);
  flex-direction: column;
  gap: var(--space-1);
}

.nav-menu.open {
  display: flex;
}

.nav-menu a {
  padding: var(--space-3) var(--space-4);
  border-radius: var(--radius-sm);
  font-size: 1rem;
  font-weight: 500;
  color: var(--color-text-muted);
  transition: color var(--transition-fast), background-color var(--transition-fast);
}

.nav-menu a:hover {
  color: var(--color-text);
  background-color: var(--color-bg-card);
  text-decoration: none;
}

/* ─── Hero ───────────────────────────────────────────────────────────────────── */
.hero {
  position: relative;
  padding-block: var(--space-20);
  text-align: center;
  overflow: hidden;
}

.hero::before {
  content: "";
  position: absolute;
  inset: 0;
  background:
    radial-gradient(ellipse 80% 60% at 50% 0%, rgba(0, 180, 216, 0.08) 0%, transparent 70%),
    radial-gradient(ellipse 60% 40% at 80% 100%, rgba(0, 119, 168, 0.06) 0%, transparent 60%);
  pointer-events: none;
}

.hero-content {
  position: relative;
  z-index: 1;
}

.hero-eyebrow {
  display: inline-flex;
  align-items: center;
  gap: var(--space-2);
  font-size: 0.8rem;
  font-weight: 600;
  letter-spacing: 0.12em;
  text-transform: uppercase;
  color: var(--color-accent);
  margin-bottom: var(--space-5);
}

.hero-eyebrow::before,
.hero-eyebrow::after {
  content: "";
  display: block;
  width: 32px;
  height: 1px;
  background: var(--color-accent);
  opacity: 0.5;
}

.hero h1 {
  margin-bottom: var(--space-5);
  letter-spacing: -0.02em;
}

.hero h1 span {
  color: var(--color-accent);
}

.hero-tagline {
  font-size: 1.1rem;
  color: var(--color-text-muted);
  max-width: 52ch;
  margin-inline: auto;
  margin-bottom: var(--space-10);
}

.hero-actions {
  display: flex;
  gap: var(--space-4);
  justify-content: center;
  flex-wrap: wrap;
}

/* ─── Buttons ────────────────────────────────────────────────────────────────── */
.btn {
  display: inline-flex;
  align-items: center;
  gap: var(--space-2);
  padding: var(--space-3) var(--space-6);
  border-radius: var(--radius-md);
  font-family: var(--font-body);
  font-size: 0.9rem;
  font-weight: 600;
  border: none;
  transition: background-color var(--transition-fast), color var(--transition-fast), box-shadow var(--transition-fast);
  text-decoration: none;
}

.btn:hover { text-decoration: none; }

.btn-primary {
  background-color: var(--color-accent);
  color: #000;
}
.btn-primary:hover {
  background-color: #33c5e0;
  color: #000;
  box-shadow: 0 4px 16px rgba(0, 180, 216, 0.35);
}

.btn-outline {
  background-color: transparent;
  color: var(--color-accent);
  border: 1px solid var(--color-accent);
}
.btn-outline:hover {
  background-color: var(--color-accent-glow);
  color: var(--color-accent);
}

/* ─── Live indicator dot ─────────────────────────────────────────────────────── */
.live-dot {
  display: inline-block;
  width: 8px;
  height: 8px;
  background-color: var(--color-success);
  border-radius: var(--radius-full);
  box-shadow: 0 0 6px var(--color-success);
  animation: pulse-dot 2s infinite;
}

@keyframes pulse-dot {
  0%, 100% { opacity: 1; }
  50%       { opacity: 0.4; }
}

/* ─── Starfield decoration ───────────────────────────────────────────────────── */
.stars-bg {
  position: fixed;
  inset: 0;
  pointer-events: none;
  z-index: 0;
  background-image:
    radial-gradient(1px 1px at 10%  20%, rgba(255,255,255,0.3) 0%, transparent 100%),
    radial-gradient(1px 1px at 25%  55%, rgba(255,255,255,0.2) 0%, transparent 100%),
    radial-gradient(1px 1px at 40%  10%, rgba(255,255,255,0.25) 0%, transparent 100%),
    radial-gradient(1px 1px at 60%  80%, rgba(255,255,255,0.15) 0%, transparent 100%),
    radial-gradient(1px 1px at 75%  35%, rgba(255,255,255,0.3) 0%, transparent 100%),
    radial-gradient(1px 1px at 88%  65%, rgba(255,255,255,0.2) 0%, transparent 100%),
    radial-gradient(1px 1px at 15%  90%, rgba(255,255,255,0.15) 0%, transparent 100%),
    radial-gradient(1px 1px at 50%  45%, rgba(255,255,255,0.1) 0%, transparent 100%),
    radial-gradient(1px 1px at 92%  15%, rgba(255,255,255,0.25) 0%, transparent 100%),
    radial-gradient(1px 1px at 33%  70%, rgba(255,255,255,0.2) 0%, transparent 100%);
}

/* ─── Section separators ─────────────────────────────────────────────────────── */
.section-divider {
  height: 1px;
  background: linear-gradient(90deg, transparent, var(--color-border), transparent);
  margin: 0;
  border: none;
}

/* ─── Footer ─────────────────────────────────────────────────────────────────── */
.site-footer {
  background-color: var(--color-bg-card);
  border-top: 1px solid var(--color-border);
  padding-block: var(--space-12);
  margin-top: var(--space-20);
}

.footer-inner {
  display: grid;
  grid-template-columns: 1fr auto;
  gap: var(--space-8);
  align-items: start;
}

.footer-brand {
  display: flex;
  align-items: center;
  gap: var(--space-3);
  font-family: var(--font-heading);
  font-weight: 700;
  font-size: 1.1rem;
  color: var(--color-text);
  margin-bottom: var(--space-3);
}

.footer-brand svg {
  width: 28px;
  height: 28px;
  color: var(--color-accent);
}

.footer-desc {
  font-size: 0.875rem;
  color: var(--color-text-dim);
  max-width: 40ch;
}

.footer-links {
  display: flex;
  gap: var(--space-6);
}

.footer-links a {
  font-size: 0.875rem;
  color: var(--color-text-muted);
}

.footer-links a:hover {
  color: var(--color-accent);
}

.footer-bottom {
  margin-top: var(--space-8);
  padding-top: var(--space-6);
  border-top: 1px solid var(--color-border);
  display: flex;
  justify-content: space-between;
  align-items: center;
  gap: var(--space-4);
  flex-wrap: wrap;
}

.footer-copyright {
  font-size: 0.8rem;
  color: var(--color-text-dim);
}

/* ─── Skip-to-content (accessibility) ───────────────────────────────────────── */
.skip-link {
  position: absolute;
  top: -100%;
  left: var(--space-4);
  background: var(--color-accent);
  color: #000;
  padding: var(--space-2) var(--space-4);
  border-radius: var(--radius-sm);
  font-weight: 600;
  z-index: 200;
  transition: top var(--transition-fast);
}

.skip-link:focus {
  top: var(--space-4);
  text-decoration: none;
  color: #000;
}

/* ─── Focus styles ───────────────────────────────────────────────────────────── */
:focus-visible {
  outline: 2px solid var(--color-accent);
  outline-offset: 3px;
  border-radius: var(--radius-sm);
}