:root {
  --bg-color: #0b1220;
  --panel-color: #131c31;
  --text-color: #eaf2ff;
  --muted-text: #b8c8e6;
  --accent-color: #2d7dff;
  --accent-hover: #4a95ff;
  --border-color: #263758;
}

* {
  box-sizing: border-box;
}

body {
  margin: 0;
  min-height: 100vh;
  display: grid;
  place-items: center;
  font-family: Inter, Arial, sans-serif;
  color: var(--text-color);
  background: radial-gradient(circle at top, #101a2e 0%, var(--bg-color) 55%);
}

.container {
  width: min(720px, 92vw);
  padding: 2rem;
  border: 1px solid var(--border-color);
  border-radius: 14px;
  background-color: var(--panel-color);
  box-shadow: 0 10px 28px rgba(0, 0, 0, 0.35);
  text-align: center;
}

h1 {
  margin: 0 0 0.75rem;
}

.subtitle {
  margin: 0 0 1.5rem;
  color: var(--muted-text);
}

.button-grid {
  display: grid;
  gap: 0.75rem;
}

.nav-button {
  display: inline-block;
  padding: 0.85rem 1rem;
  border-radius: 10px;
  text-decoration: none;
  color: var(--text-color);
  background-color: var(--accent-color);
  font-weight: 600;
  transition: transform 0.15s ease, background-color 0.15s ease;
}

.nav-button:hover,
.nav-button:focus-visible {
  background-color: var(--accent-hover);
  transform: translateY(-1px);
}