body {
  font-family: "Yu Gothic", sans-serif;
  margin: 0;
  padding: 0;
  background: radial-gradient(ellipse at top, #0a0a2a, #000);
  background-attachment: fixed;
  color: #ffec99;
  display: flex;
  flex-direction: column;
  align-items: center;
  min-height: 100vh;
}

header, footer {
  text-align: center;
  padding: 1rem;
  background: rgba(0, 0, 0, 0.4);
  color: #fff;
  width: 100%;
}

nav a {
  margin: 0 10px;
  color: white;
  text-decoration: none;
}

nav a:hover {
  text-decoration: underline;
}


h1 {
  margin-top: 30px;
  font-size: 2rem;
  letter-spacing: 2px;
  text-shadow: 0 0 10px #ffd966;
}

.calendar {
  margin-top: 40px;
  background: rgba(20, 20, 40, 0.8);
  border-radius: 12px;
  padding: 20px;
  width: 90%;
  max-width: 800px;
  backdrop-filter: blur(6px);
}

.calendar-header {
  display: flex;
  justify-content: space-between;
  align-items: center;
  margin-bottom: 10px;
}

.calendar-header button {
  background: rgba(255, 255, 200, 0.1);
  border: 1px solid rgba(255, 255, 200, 0.3);
  color: #fff4b8;
  padding: 6px 12px;
  border-radius: 8px;
  cursor: pointer;
  transition: all 0.3s ease;
}
.calendar-header button:hover {
  background: rgba(255, 255, 200, 0.25);
  box-shadow: 0 0 8px rgba(255, 255, 200, 0.4);
}

.calendar-grid {
  display: grid;
  grid-template-columns: repeat(7, 110px);
  grid-auto-rows: 120px;
  gap: 4px;
  margin-top: 10px;
}

.date {
  text-align: center;
  padding: 6px 0;
  border-radius: 6px;
  background: rgba(255, 255, 255, 0.05);
  display: flex;
  flex-wrap: wrap;
  justify-content: center;
  gap: 2px; /* アイコン間の隙間 */
}

.birthday-icon {
  width: 40px;
  height: 40px;
  object-fit: cover;
  margin-top: 20px;
}

.date {
  border: 1px solid rgba(255, 255, 255, 0.2);
  text-align: center;
  padding: 8px;
  min-height: 60px;
  color: #fff;
  background-color: rgba(255, 255, 255, 0.05);
  position: relative;

  display: flex;
  flex-wrap: wrap;
  justify-content: center;
  align-items: center;
  gap: 6px;

  padding-top: 16px;
  box-sizing: border-box;
  overflow: hidden; /* 内容が多くても崩れない */
  cursor: pointer; /* 日付セル自体がクリック対象 */
}

.date::before {
  content: attr(data-day);
  position: absolute;
  top: 4px;
  left: 6px;
  font-size: 12px;
  opacity: 0.8;
}

.birthday-details {
  margin-top: 20px;
  padding: 10px;
  border-radius: 10px;
  display: none; /* 初期は非表示 */
  position: relative; /* フッターに被らないようにする */
  z-index: 5;
}

.birthday-details img {
  width: 150px;
  height: 150px;
  border-radius: 50%;
  margin: 5px;
}

.character-detail {
  display: inline-block;
  text-align: center;
  margin: 10px;
}

.character-name {
  font-size: 14px;
  margin-top: 5px;
}


footer {
  margin: 40px 0 20px;
  font-size: 0.9rem;
  color: #c9c9c9;
  opacity: 0.7;
}