:root {
  --bg: #faf8f5;
  --text: #2b2b2b;
  --muted: #777;
  --accent: #3a6ea5;
}

@media (prefers-color-scheme: dark) {
  :root {
    --bg: #1c1c1e;
    --text: #ececec;
    --muted: #9a9a9a;
    --accent: #7fb0e6;
  }
}

* { box-sizing: border-box; }

body {
  margin: 0;
  min-height: 100vh;
  display: flex;
  flex-direction: column;
  background: var(--bg);
  color: var(--text);
  font-family: "Hiragino Sans", "Noto Sans JP", "Yu Gothic", sans-serif;
  line-height: 1.8;
}

.center {
  flex: 1;
  display: flex;
  flex-direction: column;
  justify-content: center;
  align-items: center;
  text-align: center;
  padding: 2rem 16px;
}

.label {
  margin: 0;
  color: var(--accent);
  font-size: 0.85rem;
  letter-spacing: 0.15em;
  text-transform: uppercase;
}

h1 {
  margin: 0.3em 0 0.8em;
  font-size: clamp(1.6rem, 6vw, 2.6rem);
  font-weight: 600;
}

.button {
  display: inline-block;
  margin-top: 1rem;
  padding: 0.6em 1.6em;
  border: 1px solid var(--accent);
  border-radius: 999px;
  color: var(--accent);
  text-decoration: none;
}

.button:hover {
  background: var(--accent);
  color: var(--bg);
}

footer {
  padding: 1.5rem 16px;
  text-align: center;
  color: var(--muted);
  font-size: 0.8rem;
}