/* ═══════════════════════════════════════════════════════════════════
   FUTURE ECHO — CORE DESIGN SYSTEM
   Dark. Cinematic. Futuristic. Premium.
═══════════════════════════════════════════════════════════════════ */

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

:root {
  /* Colors */
  --color-void:       #020408;
  --color-deep:       #060c12;
  --color-dark:       #0a1220;
  --color-surface:    #0f1c2e;
  --color-panel:      #141f30;
  --color-border:     rgba(100, 160, 255, 0.12);
  --color-border-glow:rgba(100, 160, 255, 0.25);

  --color-primary:    #4a9eff;
  --color-primary-dim:#2a6db5;
  --color-accent:     #7b5ea7;
  --color-accent2:    #a855f7;
  --color-gold:       #d4a843;
  --color-gold-light: #f0c060;
  --color-soul:       #8b5cf6;
  --color-soul-glow:  rgba(139, 92, 246, 0.3);

  --color-text:       #e8edf5;
  --color-text-muted: #6b7f9e;
  --color-text-dim:   #3a4f6e;

  --color-success:    #22d3a5;
  --color-warning:    #f59e0b;
  --color-error:      #ef4444;

  /* Typography */
  --font-sans:   'Space Grotesk', -apple-system, sans-serif;
  --font-serif:  'Crimson Pro', Georgia, serif;
  --font-mono:   'JetBrains Mono', monospace;

  /* Spacing */
  --space-xs:   4px;
  --space-sm:   8px;
  --space-md:   16px;
  --space-lg:   24px;
  --space-xl:   40px;
  --space-2xl:  64px;
  --space-3xl:  96px;
  --space-4xl:  128px;

  /* Radii */
  --radius-sm:  6px;
  --radius-md:  12px;
  --radius-lg:  20px;
  --radius-xl:  32px;
  --radius-full: 9999px;

  /* Transitions */
  --ease-out:   cubic-bezier(0.16, 1, 0.3, 1);
  --ease-in:    cubic-bezier(0.7, 0, 0.84, 0);
  --ease-inout: cubic-bezier(0.45, 0, 0.55, 1);
  --duration:   0.4s;

  /* Glass */
  --glass-bg:   rgba(15, 28, 46, 0.6);
  --glass-border: rgba(100, 160, 255, 0.15);
  --blur:       blur(20px);
  --blur-heavy: blur(40px);
}

html {
  scroll-behavior: smooth;
  font-size: 16px;
}

body {
  font-family: var(--font-sans);
  background-color: var(--color-void);
  color: var(--color-text);
  line-height: 1.6;
  overflow-x: hidden;
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
}

/* ─── Selection ─────────────────────────────────────────────────── */
::selection {
  background: rgba(74, 158, 255, 0.3);
  color: #fff;
}

/* ─── Scrollbar ─────────────────────────────────────────────────── */
::-webkit-scrollbar { width: 4px; }
::-webkit-scrollbar-track { background: var(--color-void); }
::-webkit-scrollbar-thumb {
  background: var(--color-primary-dim);
  border-radius: var(--radius-full);
}

/* ─── Typography ────────────────────────────────────────────────── */
h1, h2, h3, h4 { font-family: var(--font-sans); font-weight: 600; }
em { font-family: var(--font-serif); font-style: italic; font-weight: 300; }
a { text-decoration: none; color: inherit; }

/* ─── Starfield Canvas ──────────────────────────────────────────── */
#starfield {
  position: fixed;
  top: 0; left: 0;
  width: 100%; height: 100%;
  z-index: 0;
  pointer-events: none;
}

/* ─── Buttons ───────────────────────────────────────────────────── */
.btn {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  padding: 12px 24px;
  border-radius: var(--radius-md);
  font-family: var(--font-sans);
  font-size: 14px;
  font-weight: 500;
  letter-spacing: 0.01em;
  cursor: pointer;
  border: none;
  transition: all var(--duration) var(--ease-out);
  text-decoration: none;
  white-space: nowrap;
}
.btn svg { width: 16px; height: 16px; transition: transform 0.3s var(--ease-out); }
.btn:hover svg { transform: translateX(4px); }

.btn--primary {
  background: var(--color-primary);
  color: #fff;
  box-shadow: 0 0 30px rgba(74, 158, 255, 0.3);
}
.btn--primary:hover {
  background: #6ab3ff;
  box-shadow: 0 0 50px rgba(74, 158, 255, 0.5);
  transform: translateY(-1px);
}

.btn--ghost {
  background: transparent;
  color: var(--color-text-muted);
  border: 1px solid var(--color-border);
}
.btn--ghost:hover {
  background: var(--glass-bg);
  border-color: var(--color-border-glow);
  color: var(--color-text);
}

.btn--hero {
  background: linear-gradient(135deg, var(--color-primary), var(--color-soul));
  color: #fff;
  padding: 16px 32px;
  font-size: 15px;
  font-weight: 600;
  box-shadow: 0 0 60px rgba(74, 158, 255, 0.25), 0 4px 20px rgba(0,0,0,0.4);
}
.btn--hero:hover {
  box-shadow: 0 0 80px rgba(74, 158, 255, 0.4), 0 8px 40px rgba(0,0,0,0.5);
  transform: translateY(-2px);
}

.btn--ghost-hero {
  background: rgba(255,255,255,0.05);
  color: var(--color-text);
  border: 1px solid var(--color-border);
  padding: 16px 24px;
  font-size: 15px;
  backdrop-filter: var(--blur);
}
.btn--ghost-hero:hover {
  background: rgba(255,255,255,0.1);
  border-color: var(--color-border-glow);
}

.btn--gold {
  background: linear-gradient(135deg, var(--color-gold), var(--color-gold-light));
  color: #1a0e00;
  font-weight: 600;
}
.btn--gold:hover {
  box-shadow: 0 0 40px rgba(212, 168, 67, 0.4);
  transform: translateY(-1px);
}

.btn--full { width: 100%; justify-content: center; }

.play-icon {
  display: flex;
  align-items: center;
  justify-content: center;
  width: 28px;
  height: 28px;
  background: var(--color-primary);
  border-radius: 50%;
  font-size: 10px;
}

/* ─── Section Patterns ──────────────────────────────────────────── */
section { position: relative; z-index: 1; }

.section-header {
  text-align: center;
  margin-bottom: var(--space-3xl);
}
.section-tag {
  display: inline-block;
  font-family: var(--font-mono);
  font-size: 11px;
  letter-spacing: 0.2em;
  color: var(--color-primary);
  background: rgba(74, 158, 255, 0.08);
  border: 1px solid rgba(74, 158, 255, 0.2);
  padding: 5px 14px;
  border-radius: var(--radius-full);
  margin-bottom: 20px;
}
.section-title {
  font-size: clamp(36px, 5vw, 58px);
  font-weight: 600;
  line-height: 1.15;
  color: var(--color-text);
}
.section-title em {
  color: var(--color-primary);
}
.section-subtitle {
  margin-top: 16px;
  color: var(--color-text-muted);
  font-size: 18px;
  line-height: 1.7;
}

/* ─── Glass Card ────────────────────────────────────────────────── */
.glass-card {
  background: var(--glass-bg);
  border: 1px solid var(--glass-border);
  border-radius: var(--radius-xl);
  backdrop-filter: var(--blur);
  -webkit-backdrop-filter: var(--blur);
}

/* ─── Tags ──────────────────────────────────────────────────────── */
.tag {
  display: inline-flex;
  align-items: center;
  padding: 3px 10px;
  background: rgba(255,255,255,0.05);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-full);
  font-size: 11px;
  font-family: var(--font-mono);
  color: var(--color-text-muted);
  letter-spacing: 0.03em;
}
.tag--glow {
  background: rgba(74, 158, 255, 0.1);
  border-color: rgba(74, 158, 255, 0.3);
  color: var(--color-primary);
}

/* ─── Navigation ────────────────────────────────────────────────── */
.nav {
  position: fixed;
  top: 0; left: 0; right: 0;
  z-index: 1000;
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 20px 60px;
  transition: all 0.5s var(--ease-out);
}
.nav.scrolled {
  background: rgba(6, 12, 18, 0.9);
  backdrop-filter: var(--blur-heavy);
  border-bottom: 1px solid var(--color-border);
  padding: 14px 60px;
}

.nav__logo {
  display: flex;
  align-items: center;
  gap: 10px;
  font-size: 18px;
  font-weight: 600;
}
.nav__logo-icon {
  color: var(--color-primary);
  font-size: 20px;
}

.nav__links {
  display: flex;
  align-items: center;
  gap: 40px;
}
.nav__link {
  font-size: 14px;
  color: var(--color-text-muted);
  transition: color 0.3s;
}
.nav__link:hover { color: var(--color-text); }

.nav__actions {
  display: flex;
  align-items: center;
  gap: 12px;
}

.nav__burger {
  display: none;
  flex-direction: column;
  gap: 5px;
  background: none;
  border: none;
  cursor: pointer;
  padding: 4px;
}
.nav__burger span {
  display: block;
  width: 24px;
  height: 2px;
  background: var(--color-text);
  border-radius: 2px;
  transition: all 0.3s;
}

/* ─── Responsive ────────────────────────────────────────────────── */
@media (max-width: 1024px) {
  .nav { padding: 20px 30px; }
  .nav.scrolled { padding: 14px 30px; }
  .nav__links { gap: 24px; }
}

@media (max-width: 768px) {
  .nav__links, .nav__actions { display: none; }
  .nav__burger { display: flex; }
  section { padding-left: 20px; padding-right: 20px; }
}