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

:root {
  --green: #7C3AED;
  --green-dark: #5B21B6;
  --green-light: #A78BFA;
  --green-glow: rgba(124,58,237,0.15);
  --bg: #09090b;
  --bg-2: #111113;
  --card: #18181b;
  --card-hover: #1f1f23;
  --border: rgba(255,255,255,0.06);
  --border-light: rgba(255,255,255,0.1);
  --text: #fafafa;
  --sub: #a1a1aa;
  --muted: #52525b;
  --danger: #ef4444;
  --warning: #f59e0b;
  --radius: 16px;
  --radius-sm: 10px;
  --radius-lg: 24px;
  --shadow: 0 4px 24px rgba(0,0,0,0.3);
  --transition: 0.2s ease;
}

html { scroll-behavior: smooth; }

body {
  font-family: 'Inter', -apple-system, BlinkMacSystemFont, sans-serif;
  background: var(--bg);
  color: var(--text);
  line-height: 1.6;
  -webkit-font-smoothing: antialiased;
  overflow-x: hidden;
}

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

/* ─── NAV ─── */
nav {
  position: fixed; top: 0; left: 0; right: 0; z-index: 100;
  background: rgba(9,9,11,0.85);
  backdrop-filter: blur(24px);
  -webkit-backdrop-filter: blur(24px);
  border-bottom: 1px solid var(--border);
  padding: 0 24px;
}

.nav-inner {
  max-width: 1100px; margin: 0 auto;
  display: flex; align-items: center; justify-content: space-between;
  height: 64px;
}

.nav-brand {
  display: flex; align-items: center; gap: 10px;
  font-weight: 700; font-size: 18px;
}

.nav-brand img, .nav-brand svg { width: 28px; height: 28px; }

.nav-links { display: flex; gap: 32px; }
.nav-links a { color: var(--sub); font-size: 14px; font-weight: 500; transition: color var(--transition); }
.nav-links a:hover { color: var(--text); }

.nav-cta {
  background: var(--green); color: #000;
  padding: 8px 20px; border-radius: var(--radius-sm);
  font-size: 14px; font-weight: 600;
  transition: all var(--transition);
  box-shadow: 0 2px 0 0 #0d7a30, 0 4px 12px rgba(37,211,102,0.2);
}
.nav-cta:hover { transform: translateY(-1px); box-shadow: 0 3px 0 0 #0d7a30, 0 6px 16px rgba(37,211,102,0.3); }

.nav-toggle { display: none; background: none; border: none; color: var(--text); cursor: pointer; padding: 8px; }
.nav-toggle svg { width: 24px; height: 24px; }

/* ─── BUTTONS ─── */
.btn {
  display: inline-flex; align-items: center; gap: 10px;
  font-family: inherit; font-size: 16px; font-weight: 700;
  text-decoration: none; padding: 16px 32px;
  border-radius: 14px; border: none; cursor: pointer;
  transition: all 0.15s; position: relative; overflow: hidden;
}

.btn-primary {
  background: linear-gradient(180deg, #30e87a 0%, #25D366 50%, #1db954 100%);
  color: #000;
  box-shadow: 0 4px 0 0 #0d7a30, 0 6px 24px rgba(37,211,102,0.25), inset 0 1px 0 rgba(255,255,255,0.25);
}
.btn-primary:hover { transform: translateY(-2px); box-shadow: 0 6px 0 0 #0d7a30, 0 10px 32px rgba(37,211,102,0.35), inset 0 1px 0 rgba(255,255,255,0.25); }
.btn-primary:active { transform: translateY(2px); box-shadow: 0 2px 0 0 #0d7a30, 0 3px 8px rgba(37,211,102,0.15); }

.btn-secondary {
  background: var(--card); color: var(--text);
  border: 1px solid var(--border);
}
.btn-secondary:hover { background: var(--card-hover); border-color: var(--border-light); }

.btn-ghost {
  background: transparent; color: var(--sub);
  border: 1px solid var(--border);
}
.btn-ghost:hover { color: var(--text); border-color: var(--border-light); background: rgba(255,255,255,0.02); }

.btn svg { width: 20px; height: 20px; }

/* Button Loading */
.btn.loading { pointer-events: none; opacity: 0.8; }
.btn.loading::after {
  content: ''; position: absolute;
  width: 18px; height: 18px;
  border: 2px solid transparent;
  border-top-color: currentColor;
  border-radius: 50%;
  animation: spin 0.6s linear infinite;
}
.btn.loading .btn-text { opacity: 0; }
@keyframes spin { to { transform: rotate(360deg); } }

/* ─── BADGES ─── */
.badge {
  display: inline-flex; align-items: center; gap: 6px;
  font-size: 12px; font-weight: 600;
  padding: 4px 12px; border-radius: 8px;
}
.badge-green { background: rgba(37,211,102,0.1); color: var(--green); }
.badge-green-solid { background: var(--green); color: #000; }
.badge-muted { background: rgba(255,255,255,0.05); color: var(--muted); }
.badge-warning { background: rgba(245,158,11,0.1); color: var(--warning); }
.badge-danger { background: rgba(239,68,68,0.1); color: var(--danger); }

.badge-dot { width: 6px; height: 6px; border-radius: 50%; }
.badge-dot.green { background: var(--green); animation: pulse 2s ease-in-out infinite; }
@keyframes pulse { 0%, 100% { opacity: 1; } 50% { opacity: 0.4; } }

/* ─── CARDS ─── */
.card {
  background: var(--card);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  transition: all var(--transition);
}
.card:hover { border-color: rgba(255,255,255,0.1); }
.card.interactive:hover { transform: translateY(-3px); border-color: rgba(37,211,102,0.2); }

/* ─── SKELETON LOADING ─── */
.skeleton {
  background: linear-gradient(90deg, var(--card) 25%, rgba(255,255,255,0.05) 50%, var(--card) 75%);
  background-size: 200% 100%;
  animation: shimmer 1.5s infinite;
  border-radius: 8px;
}
.skeleton-text { height: 14px; margin-bottom: 8px; }
.skeleton-text:last-child { width: 60%; }
.skeleton-circle { border-radius: 50%; }
.skeleton-card { height: 120px; border-radius: var(--radius); }
@keyframes shimmer { 0% { background-position: 200% 0; } 100% { background-position: -200% 0; } }

/* ─── LOADING OVERLAY ─── */
.loading-overlay {
  position: fixed; inset: 0; z-index: 999;
  background: var(--bg);
  display: flex; flex-direction: column; align-items: center; justify-content: center;
  transition: opacity 0.4s;
}
.loading-overlay.hidden { opacity: 0; pointer-events: none; }

.loading-spinner {
  width: 40px; height: 40px;
  border: 3px solid var(--border);
  border-top-color: var(--green);
  border-radius: 50%;
  animation: spin 0.8s linear infinite;
}

.loading-text { margin-top: 16px; font-size: 14px; color: var(--muted); }

/* ─── SECTION ─── */
.section { max-width: 1100px; margin: 0 auto; padding: 100px 24px; }
.section-header { text-align: center; margin-bottom: 56px; }
.section-tag { font-size: 13px; font-weight: 600; color: var(--green); text-transform: uppercase; letter-spacing: 1.5px; margin-bottom: 12px; }
.section-title { font-size: clamp(28px, 4vw, 40px); font-weight: 800; letter-spacing: -1px; }
.section-desc { font-size: 16px; color: var(--sub); max-width: 500px; margin: 12px auto 0; }

/* ─── DECORATIVE ─── */
.glow {
  position: absolute; pointer-events: none;
  width: 600px; height: 600px;
  border-radius: 50%;
  filter: blur(120px);
  opacity: 0.07;
}
.glow-green { background: var(--green); }
.glow-teal { background: var(--green-dark); }

.grid-bg {
  position: absolute; inset: 0; pointer-events: none;
  background-image:
    linear-gradient(rgba(255,255,255,0.02) 1px, transparent 1px),
    linear-gradient(90deg, rgba(255,255,255,0.02) 1px, transparent 1px);
  background-size: 60px 60px;
  mask-image: radial-gradient(ellipse at center, black 0%, transparent 70%);
  -webkit-mask-image: radial-gradient(ellipse at center, black 0%, transparent 70%);
}

.noise {
  position: fixed; inset: 0; pointer-events: none; z-index: 9999;
  opacity: 0.03;
  background-image: url("data:image/svg+xml,%3Csvg viewBox='0 0 256 256' xmlns='http://www.w3.org/2000/svg'%3E%3Cfilter id='n'%3E%3CfeTurbulence type='fractalNoise' baseFrequency='0.9' numOctaves='4' stitchTiles='stitch'/%3E%3C/filter%3E%3Crect width='100%25' height='100%25' filter='url(%23n)'/%3E%3C/svg%3E");
}

/* ─── FOOTER ─── */
footer { border-top: 1px solid var(--border); padding: 32px 24px; }
.footer-inner {
  max-width: 1100px; margin: 0 auto;
  display: flex; align-items: center; justify-content: space-between;
  flex-wrap: wrap; gap: 16px;
}
.footer-brand { display: flex; align-items: center; gap: 8px; font-weight: 700; font-size: 15px; }
.footer-brand img, .footer-brand svg { width: 22px; height: 22px; }
.footer-text { font-size: 13px; color: var(--muted); }
.footer-links { display: flex; gap: 24px; }
.footer-links a { font-size: 13px; color: var(--sub); transition: color var(--transition); }
.footer-links a:hover { color: var(--text); }

/* ─── MOBILE ─── */
@media (max-width: 768px) {
  .nav-toggle { display: block; }
  .nav-links {
    display: none; position: absolute; top: 64px; left: 0; right: 0;
    background: rgba(9,9,11,0.95); backdrop-filter: blur(20px);
    flex-direction: column; padding: 16px 24px;
    border-bottom: 1px solid var(--border);
  }
  .nav-links.open { display: flex; }
  .nav-links a { padding: 12px 0; }
  .nav-cta { display: none; }
  .footer-inner { flex-direction: column; text-align: center; }
}