/* Minimal reset and CSS reset for a clean baseline */
* { box-sizing: border-box; margin: 0; padding: 0; }

:root {
  --bg: #0a0a0f;
  --bg-deep: #050509;
  --grid: rgba(255, 255, 255, 0.06);
  --text: #e6eafc;
  --muted: #b6c3e6;
  --indigo: #4f46e5;       /* neon indigo */
  --indigo-accent: #7c8cff;
  --glass: rgba(8, 12, 28, 0.66);
  --glass-border: rgba(124, 140, 255, 0.28);
  --card-shadow: rgba(0, 0, 0, 0.6);
  --cta: rgba(124, 93, 255, 0.95);
  --cta-border: rgba(124, 93, 255, 0.6);
}

html, body {
  height: 100%;
  background-color: var(--bg);
  color: var(--text);
  font-family: ui-sans-serif, system-ui, -apple-system, "Segoe UI", Roboto, "Helvetica Neue", Arial;
  line-height: 1.5;
  /* grid paper background (black & dark grey) */
  background-image:
    linear-gradient(to right, rgba(255,255,255,.04) 0 1px, transparent 1px),
    linear-gradient(to bottom, rgba(255,255,255,.04) 0 1px, transparent 1px);
  background-size: 28px 28px, 28px 28px;
  background-attachment: fixed;
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
}

body {
  display: flex;
  flex-direction: column;
  min-height: 100vh;
}

/* Header styling */
.site-header {
  display: flex;
  align-items: center;
  justify-content: center;
  padding: 14px 16px;
  position: sticky;
  top: 0;
  z-index: 10;
  background: rgba(6, 6, 12, 0.8);
  border-bottom: 1px solid rgba(80, 90, 140, 0.25);
  backdrop-filter: blur(6px);
  -webkit-backdrop-filter: blur(6px);
}
.brand {
  font-weight: 700;
  letter-spacing: .4px;
  color: #e8f0ff;
  text-shadow: 0 0 8px rgba(76, 167, 255, 0.8);
  font-size: 1.05rem;
}

/* Main content layout */
main {
  flex: 1;
  display: grid;
  place-items: start center;
  padding: 20px 12px;
}

/* Hero section (centerpiece with QR) */
.hero {
  width: min(92%, 860px);
  text-align: center;
  padding: 20px;
  border-radius: 18px;
  /* frosted glass look */
  background: var(--glass);
  border: 1px solid var(--glass-border);
  backdrop-filter: blur(8px) saturate(1.15);
  -webkit-backdrop-filter: blur(8px) saturate(1.15);
  box-shadow: 0 20px 60px rgba(0,0,0,.65), inset 0 1px 0 rgba(255,255,255,.04);
}

.hero h1 {
  font-size: 1.6rem;
  line-height: 1.15;
  margin-bottom: 8px;
  color: #eaf2ff;
  text-shadow: 0 0 10px rgba(67, 140, 255, 0.6);
}
.hero h2 {
  font-size: 1.05rem;
  color: var(--muted);
  margin-bottom: 16px;
}

.qr-center {
  display: grid;
  place-items: center;
  padding: 12px 6px 6px;
}

.qr-center img {
  width: 68vmin;
  max-width: 420px;
  height: auto;
  display: block;
  border-radius: 14px;
  box-shadow: 0 18px 40px rgba(0,0,0,.65);
  filter: saturate(1.05);
  /* no extra images beyond the provided QR code image */
}

.telegram-link {
  margin-top: 14px;
}

.telegram-link a {
  display: inline-block;
  padding: 12px 18px;
  border-radius: 999px;
  background: rgba(60, 70, 130, 0.92);
  color: #eaffff;
  text-decoration: none;
  border: 1px solid rgba(150, 170, 255, 0.8);
  box-shadow: 0 6px 14px rgba(0,0,0,.35);
  transition: transform .15s ease, background .15s ease;
}
.telegram-link a:hover,
.telegram-link a:focus-visible {
  transform: translateY(-1px);
  background: rgba(80, 100, 190, 1);
  outline: none;
}
.telegram-link a:focus-visible {
  box-shadow: 0 0 0 3px rgba(124, 93, 255, 0.6);
}

/* Footer with product advertisement */
.site-footer {
  padding: 18px 12px;
  text-align: center;
  color: #cbd5e1;
  border-top: 1px solid rgba(120,120,200,.25);
  background: rgba(2,4,12,.6);
}
.advertisement a {
  color: #b8c6ff;
  text-decoration: none;
  font-size: 13px;
  padding: 6px 10px;
  border-radius: 6px;
  border: 1px solid rgba(120,140,255,.5);
  background: rgba(0,0,0,.25);
}
.advertisement a:hover {
  color: #e8f0ff;
  background: rgba(20,24,36,.5);
}
.gratitude {
  margin-top: 8px;
  font-size: 13px;
  color: #cbd5e1;
}

/* Accessibility: focus visible for anchors and interactive elements */
a:focus-visible {
  outline: 2px solid var(--indigo);
  outline-offset: 2px;
  border-radius: 6px;
}

/* Responsive/mobile-first adjustments */
@media (min-width: 640px) {
  .hero {
    padding: 28px;
  }
  .hero h1 { font-size: 1.9rem; }
  .hero h2 { font-size: 1.15rem; }
}

@media (min-width: 1024px) {
  /* Slightly larger typography on wide screens */
  .hero { padding: 34px; }
  .hero h1 { font-size: 2.2rem; }
  .hero h2 { font-size: 1.25rem; }
  .site-header { padding: 18px 24px; }
  .advertisement a { font-size: 14px; padding: 8px 12px; }
}