:root {
  --bg: #0f172a;
  --card: #1e293b;
  --text: #e2e8f0;
  --muted: #94a3b8;
  --accent: #38bdf8;
  --accent-dark: #0ea5e9;
}

* {
  box-sizing: border-box;
}

body {
  margin: 0;
  min-height: 100vh;
  display: flex;
  align-items: center;
  justify-content: center;
  padding: 24px;
  background: radial-gradient(circle at 20% 20%, #1e293b 0%, var(--bg) 60%);
  color: var(--text);
  font-family: system-ui, -apple-system, "Segoe UI", "Microsoft YaHei", sans-serif;
}

.card {
  width: 100%;
  max-width: 480px;
  padding: 40px 32px;
  border-radius: 16px;
  background: var(--card);
  border: 1px solid rgba(148, 163, 184, 0.2);
  box-shadow: 0 20px 50px rgba(0, 0, 0, 0.4);
  text-align: center;
}

h1 {
  margin: 0 0 16px;
  font-size: 28px;
  letter-spacing: 0.5px;
}

.message {
  margin: 0 0 28px;
  min-height: 48px;
  font-size: 17px;
  line-height: 1.6;
  color: var(--muted);
  transition: color 0.25s ease;
}

.message.active {
  color: var(--accent);
}

.btn {
  padding: 12px 28px;
  font-size: 16px;
  font-family: inherit;
  color: #0b1220;
  background: var(--accent);
  border: none;
  border-radius: 999px;
  cursor: pointer;
  transition: transform 0.15s ease, background 0.2s ease, box-shadow 0.2s ease;
}

.btn:hover {
  background: var(--accent-dark);
  box-shadow: 0 8px 20px rgba(56, 189, 248, 0.35);
}

.btn:active {
  transform: scale(0.96);
}

.btn:focus-visible {
  outline: 2px solid #f8fafc;
  outline-offset: 3px;
}

.counter {
  margin: 20px 0 0;
  font-size: 14px;
  color: var(--muted);
}

#count {
  font-weight: 700;
  color: var(--text);
}