body { font-family: system-ui, -apple-system, sans-serif; padding: 24px; max-width: 420px; margin: 0 auto; }
.card { border: 1px solid #ddd; border-radius: 12px; padding: 18px; }
label { display:block; margin-top: 12px; font-size: 14px; }
input { width: 100%; padding: 10px; margin-top: 6px; box-sizing: border-box; }
button { margin-top: 16px; width: 100%; padding: 10px; }
.error { color: #b00020; margin-top: 8px; }
/* Title */
.title {
  text-align: center;
  margin: 8px 0 16px;
  font-weight: 700;
  letter-spacing: 0.5px;
  font-size: clamp(28px, 4vw, 40px); /* スマホ〜PCで自動調整 */
}

.card-title {
  text-align: center;
  margin: 0 0 12px;
  font-weight: 700;
  font-size: clamp(18px, 3vw, 22px);
}