/* ======= 全域設定 ======= */
body {
  font-family: sans-serif;
  margin: 0;
  background: #f5f5f5;
  text-align: center;
}

/* ======= 頁首 Header ======= */
header {
  background: #2c3e50;
  color: white;
  padding: 20px;
  text-align: center;
}

/* --- Logo 動態漂浮效果 --- */
.logo {
  height: 80px;                     /* 保留原本尺寸設定 */
  width: auto;
  animation: float 3s ease-in-out infinite;
  display: block;
  margin: 40px auto 20px;
}

@keyframes float {
  0%, 100% {
    transform: translateY(0);
  }
  50% {
    transform: translateY(-15px);
  }
}

/* ======= 主內容 ======= */
main {
  padding: 20px;
}

/* ======= 頁尾 Footer ======= */
footer {
  background: #34495e;
  color: white;
  padding: 10px;
}