*, *::before, *::after {
  box-sizing: border-box;
  margin: 0;
  padding: 0;
}

:root {
  --bg: #ffffff;
  --text: #111111;
  --btn-bg: #111111;
  --btn-text: #ffffff;
  --btn-hover: #444444;
  --muted: #666666;
}

@media (prefers-color-scheme: dark) {
  :root {
    --bg: #0d0d0d;
    --text: #f2f2f2;
    --btn-bg: #f2f2f2;
    --btn-text: #0d0d0d;
    --btn-hover: #cccccc;
    --muted: #888888;
  }
}

body {
  font-family: 'Inter', system-ui, -apple-system, sans-serif;
  background-color: var(--bg);
  color: var(--text);
  min-height: 100dvh;
  display: flex;
  align-items: center;
  justify-content: center;
  padding: 1.5rem;
  transition: background-color 0.25s, color 0.25s;
}

.page {
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 2rem;
  text-align: center;
  max-width: 560px;
  width: 100%;
}

h1 {
  font-size: clamp(1.6rem, 6vw, 2.75rem);
  font-weight: 700;
  line-height: 1.35;
}

/* CTA Button */
.btn {
  display: inline-block;
  background: var(--btn-bg);
  color: var(--btn-text);
  padding: 0.9rem 2.5rem;
  border-radius: 10px;
  font-family: inherit;
  font-size: 1rem;
  font-weight: 600;
  text-decoration: none;
  transition: background 0.2s, transform 0.1s;
  -webkit-tap-highlight-color: transparent;
  cursor: pointer;
}

.btn:hover {
  background: var(--btn-hover);
}

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

/* Counter page */
.counter-text {
  font-size: clamp(1.2rem, 5vw, 1.9rem);
  font-weight: 400;
  line-height: 1.6;
}

.counter-text strong {
  font-weight: 700;
}

.back {
  color: var(--muted);
  font-size: 0.9rem;
  text-decoration: none;
  border-bottom: 1px solid currentColor;
  transition: color 0.15s;
}

.back:hover {
  color: var(--text);
}