:root {
  --bg: #0e0e10;
  --card: #17171a;
  --text: #f4f4f5;
  --muted: #a1a1aa;
  --accent: #d0021b;
  --zalo: #0068ff;
  --line: #2a2a30;
}

* { box-sizing: border-box; }

html, body {
  margin: 0;
  min-height: 100%;
}

body {
  display: flex;
  align-items: center;
  justify-content: center;
  padding: 24px;
  background: var(--bg);
  color: var(--text);
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, Helvetica, Arial, sans-serif;
  -webkit-font-smoothing: antialiased;
}

.card {
  width: 100%;
  max-width: 420px;
  padding: 40px 28px;
  text-align: center;
  background: var(--card);
  border: 1px solid var(--line);
  border-radius: 20px;
}

.brand {
  margin: 0;
  font-size: clamp(30px, 9vw, 44px);
  font-weight: 800;
  letter-spacing: 3px;
}

.tagline {
  margin: 6px 0 32px;
  font-size: 14px;
  letter-spacing: 4px;
  text-transform: uppercase;
  color: var(--muted);
}

.contact {
  display: flex;
  flex-direction: column;
  gap: 14px;
}

.zalo,
.call {
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 12px;
  padding: 14px 18px;
  border-radius: 14px;
  text-decoration: none;
  font-weight: 700;
  transition: transform .15s ease, box-shadow .15s ease, background .15s ease;
}

.zalo {
  background: #ffffff;
  color: var(--zalo);
  font-size: clamp(20px, 6.5vw, 26px);
  letter-spacing: 1px;
}

.zalo img {
  display: block;
  width: 44px;
  height: 44px;
  flex: none;
}

.call {
  background: transparent;
  border: 1px solid var(--line);
  color: var(--text);
  font-size: 16px;
}

.zalo:hover,
.call:hover {
  transform: translateY(-2px);
}

.zalo:hover {
  box-shadow: 0 8px 24px rgba(0, 104, 255, .28);
}

.call:hover {
  background: #1f1f24;
  border-color: var(--accent);
}

.zalo:active,
.call:active {
  transform: translateY(0);
}

@media (prefers-reduced-motion: reduce) {
  .zalo, .call { transition: none; }
  .zalo:hover, .call:hover { transform: none; }
}