/* Navy carbon-fiber inspired background with silver accents and frosted glass */

/* Root tokens (mobile-first) */
:root{
  --bg: #0b1a2b;
  --card: rgba(255,255,255,.92);
  --text: #0a0a0a;
  --muted: #5a5a5a;
  --border: rgba(0,0,0,.14);
  --focus: #cbd5e1;
  --shadow: 0 12px 40px rgba(0,0,0,.25);
  --cta: #6c8bff;
  --silver: #e6e8ea;
  --silver-dark: #cbd5e1;
  --bg-stripe-1: rgba(255,255,255,.04);
  --bg-stripe-2: rgba(0,0,0,.08);
}

/* Reset */
*, *::before, *::after { box-sizing: border-box; }

/* Page base (mobile-first) */
html, body { height: 100%; }
body {
  margin: 0;
  color: var(--text);
  background: var(--bg);
  font-family: ui-sans-serif, system-ui, -apple-system, "Segoe UI", Roboto, "Helvetica Neue", Arial;
  min-height: 100dvh;
  display: grid;
  grid-template-rows: auto 1fr auto;
  overflow-x: hidden;
  /* navy carbon-fiber pattern with subtle stripes */
  background-image:
    repeating-linear-gradient(45deg, rgba(255,255,255,.04) 0 2px, transparent 2px 8px),
    repeating-linear-gradient(-45deg, rgba(0,0,0,.08) 0 2px, transparent 2px 8px);
  background-size: 12px 12px;
  background-color: #0b1a2b;
  box-shadow: inset 0 0 120px rgba(0,0,0,.15);
  isolation: isolate;
}

/* Header */
.site-header {
  width: 100%;
  display: flex;
  justify-content: center;
  align-items: center;
  padding: 12px 16px;
  position: sticky;
  top: 0;
  z-index: 5;
  background: rgba(0,0,0,.55);
  border-bottom: 1px solid rgba(255,255,255,.15);
}
.brand {
  font-weight: 700;
  color: #eaeef5;
  text-shadow: 0 0 8px rgba(0,0,0,.4);
  display: inline-flex;
  align-items: center;
  gap: 8px;
}

/* Main container */
main {
  width: 100%;
  display: grid;
  place-items: center;
  padding: 2rem 1rem;
}

/* Hero block (central donation QR) */
.hero {
  width: min(92%, 860px);
  padding: 2rem;
  border-radius: 16px;
  text-align: center;
  display: grid;
  gap: 1rem;
  background: rgba(255,255,255,.92); /* frosted glass look */
  backdrop-filter: blur(6px);
  -webkit-backdrop-filter: blur(6px);
  border: 1px solid rgba(0,0,0,.12);
  box-shadow: 0 12px 40px rgba(0,0,0,.25);
  position: relative;
  overflow: hidden;
}
.hero::before {
  content: "";
  position: absolute;
  inset: -2px;
  background: radial-gradient(circle at 50% 50%, rgba(0,0,0,.08), transparent 40%);
  filter: blur(14px);
  z-index: -1;
  animation: glow 12s ease-in-out infinite;
}
@keyframes glow { 0%,100% { transform: scale(1); } 50% { transform: scale(1.02); } }

.hero h1 {
  margin: 0;
  font-size: clamp(1.6rem, 2vw + 1rem, 2.8rem);
  color: #0a0a0a;
}
.subhead {
  font-size: clamp(1rem, 0.8vw + 0.8rem, 1.25rem);
  color: #3a3a3a;
  margin: 0;
}
.qr-hero {
  display: grid;
  place-items: center;
  margin-top: 6px;
}
.qr-hero img {
  width: min(72vw, 420px);
  height: auto;
  border-radius: 14px;
  padding: 12px;
  background: rgba(0,0,0,.18);
  border: 1px solid rgba(0,0,0,.15);
  box-shadow: 0 14px 38px rgba(0,0,0,.25);
}
.telegram-link {
  color: #2a2a2a;
  font-size: 1rem;
  margin: 0;
}
.telegram-link a {
  color: #1a1a1a;
  text-decoration: none;
  border-bottom: 1px dotted rgba(0,0,0,.4);
}
.telegram-link a:hover, .telegram-link a:focus { color: #000; text-decoration: underline; }

/* Footer with small advertisement button-like link */
.site-footer {
  width: 100%;
  padding: 1rem;
  text-align: center;
  background: rgba(0,0,0,.55);
  color: #e9f0f8;
  border-top: 1px solid rgba(255,255,255,.15);
}
.footer-ad {
  font-size: 0.95rem;
  color: #e9f0f8;
}
.footer-ad a {
  display: inline-block;
  padding: 0.6em 1.0em;
  border-radius: 999px;
  background: linear-gradient(135deg, #5a9aff, #4c7aff);
  color: #061a2a;
  text-decoration: none;
  border: 1px solid rgba(0,0,0,.15);
  transition: transform .2s ease;
}
.footer-ad a:hover, .footer-ad a:focus {
  transform: translateY(-1px);
  filter: brightness(1.05);
}
.footer-ad a:active { transform: translateY(0); }
.gratitude { margin: 0.5rem 0 0; font-size: 0.92rem; color: #d6ffd6; }

/* Focus styles for accessibility */
:focus-visible { outline: 2px solid var(--focus); outline-offset: 2px; }

/* Responsive tweaks */
@media (min-width: 768px) {
  .hero { padding: 2.5rem; }
  .brand { font-size: 1.05rem; }
}
@media (min-width: 1024px) {
  .hero { padding: 3rem; }
  .qr-hero img { width: 420px; }
}