body {
  font-family: 'Sawarabi Mincho', 'Noto Serif JP', serif;
  margin: 0;
  padding: 0;
  background: radial-gradient(circle at 20% 30%, #1b0033, #0d0011 80%);
  color: #f2d58a;
}

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

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

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

/* タイトル & 詩 */
#intro {
  text-align: center;
  padding: 3rem 1rem;
  img{
    width: 100%;
    height: auto;
    max-width: 500px;
  }
}

/* 世界観への扉 */
#world-doors {
  display: flex;
  flex-wrap: wrap;
  justify-content: center;
  gap: 20px;
  padding: 2rem;
}

.door {
  position: relative;
  width: 200px;
  height: 300px;
  overflow: hidden;
  text-decoration: none;
  color: white;
  border-radius: 10px;
  box-shadow: 0 4px 6px rgba(0,0,0,0.2);
  transition: transform 0.3s, box-shadow 0.3s;
}

.door img {
  width: 100%;
  height: 100%;
  object-fit: cover;
  display: block;
  filter: brightness(0.7);
  transition: filter 0.3s, transform 0.3s;
}

.door-title {
  position: absolute;
  bottom: 0;
  width: 100%;
  text-align: center;
  background: rgba(0,0,0,0.5);
  padding: 0.5rem;
  font-size: 1.1rem;
}

/* ホバー演出 */
.door:hover img {
  filter: brightness(1);
  transform: scale(1.05);
}

.door:hover {
  box-shadow: 0 8px 15px rgba(0,0,0,0.4);
}


.calendar-button {
  display: inline-block;
  margin: 20px auto;
  padding: 12px 24px;
  background-color: #17184b; /* 緑系などに変更OK */
  color: white;
  font-size: 1.1rem;
  font-weight: bold;
  text-decoration: none;
  border-radius: 8px;
  transition: background-color 0.3s, transform 0.2s;
}

.calendar-button-container {
  text-align: center;
}


.calendar-button:hover {
  background-color: #f2d58a;
  transform: scale(1.05);
}

.characters-button {
  display: inline-block;
  margin: 20px auto;
  padding: 12px 24px;
  background-color: #17184b; /* 緑系などに変更OK */
  color: white;
  font-size: 1.1rem;
  font-weight: bold;
  text-decoration: none;
  border-radius: 8px;
  transition: background-color 0.3s, transform 0.2s;
}

.characters-button-container {
  text-align: center;
}


.characters-button:hover {
  background-color: #f2d58a;
  transform: scale(1.05);
}

/* 星背景用キャンバス */
#starfield {
  position: fixed;      /* スクロールしても背景として固定 */
  top: 0;
  left: 0;
  width: 100%;
  height: 100%;
  z-index: -1;          /* 他の要素の下に置く */
}

/* 扉やカードを少し透明にして星が見えるように */
.door, .character-card {
  background-color: rgba(255, 255, 255, 0.1);  /* 透明度調整OK */
  backdrop-filter: blur(5px); /* 背景を少しぼかす効果で幻想的に */
}


@media screen and (max-width: 600px) {
  body {
    font-size: 14px;
  }

  header nav {
    display: flex;
    flex-wrap: wrap;
    justify-content: center;
    gap: 4px;
    font-size: 13px;
  }

  header nav a {
    display: inline-block;
    padding: 4px 6px;
    border-radius: 4px;
    background: rgba(255, 255, 255, 0.1);
    margin: 2px;
  }

  /* 世界観への扉を2列表示 */
  #world-doors {
    display: grid;
    grid-template-columns: repeat(2, 1fr); /* 2列表示 */
    gap: 10px;
    padding: 10px;
  }

  .door {
    width: 100%;               /* 横幅は親に合わせる */
    height: 300px;             /* 高さを固定 */
    position: relative;
    overflow: hidden;
    border-radius: 10px;
  }

  .door img {
    width: 100%;
    height: 100%;              /* 親の高さに合わせる */
    object-fit: cover;         /* 枠いっぱいに収める（縦横比維持＋切り抜き） */
    display: block;
    filter: brightness(0.7);
    transition: filter 0.3s, transform 0.3s;
  }

  .door-title {
    font-size: 0.95em;
    padding: 0.4rem;
  }

  /* ボタン幅を広げる */
  .calendar-button,
  .characters-button {
    width: 90%;
    padding: 10px 0;
    font-size: 0.95em;
  }
}