@charset "utf-8";
/* CSS Document */
:root {
  --color-main: #5A4032;
  --color-accent: #9FC9B4;
  --color-bg: #F4EFE9;
  --book-width: 260px;
  --book-height: 360px;
}

#intro-overlay {
  position: fixed; top: 0; left: 0; width: 100%; height: 100%;
  background: #fff; z-index: 9999; display: flex; justify-content: center; align-items: center;
  transition: opacity 1s ease-in-out;
}

.book-container { perspective: 2000px; }

/* --- 【PC用：基本設定】 --- */
.book {
  width: var(--book-width);
  height: var(--book-height);
  position: relative;
  transform-style: preserve-3d;
  /* PCのデフォルト角度 */
  transform: rotateX(15deg) rotateY(-15deg);
  /* PC用のアニメーションを適用 */
  animation: pageFloatPC 4s ease-in-out infinite;
}

@keyframes pageFloatPC {
  0% { transform: rotateX(15deg) rotateY(-15deg); }
  50% { transform: rotateX(16deg) rotateY(-14deg); }
  100% { transform: rotateX(15deg) rotateY(-15deg); }
}

.cover-unit {
  width: 100%; height: 100%;
  position: absolute; transform-style: preserve-3d;
  transform-origin: left; z-index: 20;
  transition: transform 0.15s linear; 
}

.cover-front {
  position: absolute; width: 100%; height: 100%;
  backface-visibility: hidden;
  background: var(--color-main);
  background-image: 
    linear-gradient(135deg, rgba(255,255,255,0.03) 0%, transparent 100%),
    repeating-linear-gradient(90deg, transparent, transparent 1px, rgba(0,0,0,0.05) 2px);
  display: flex; justify-content: center; align-items: center;
  border-radius: 3px 6px 6px 3px;
  outline: 1px solid rgba(244, 239, 233, 0.15);
  outline-offset: -15px;
  box-shadow: inset 4px 0 6px rgba(0,0,0,0.3), 5px 10px 20px rgba(0,0,0,0.2);
}

.cover-front::after {
  content: ""; position: absolute; top: 0; left: 0; width: 100%; height: 100%;
  background: linear-gradient(135deg, rgba(255,255,255,0.1) 0%, rgba(255,255,255,0) 30%, rgba(255,255,255,0.05) 50%, transparent 100%);
  pointer-events: none;
}

.title-box {
  border-top: 1px solid rgba(244, 239, 233, 0.3);
  border-bottom: 1px solid rgba(244, 239, 233, 0.3);
  padding: 20px 0; width: 80%; text-align: center;
}

.main-title {
  color: var(--color-bg); font-family: 'Playfair Display', serif;
  font-size: 1.5rem; font-weight: bold; letter-spacing: 0.2rem;
  text-transform: uppercase; text-shadow: 0.5px 0.5px 0px rgba(0,0,0,0.5);
}

.cover-back {
  position: absolute; width: 100%; height: 100%;
  backface-visibility: hidden; transform: rotateY(180deg);
  background-color: var(--color-bg); border-radius: 6px 3px 3px 6px;
  box-shadow: inset -10px 0 20px rgba(0,0,0,0.1);
  background-image: linear-gradient(to right, rgba(0,0,0,0.05) 0%, transparent 10%);
}

.page-inside-right {
  position: absolute; top: 5px; left: 5px;
  width: calc(var(--book-width) - 10px); height: calc(var(--book-height) - 10px);
  background-color: var(--color-bg);
  display: flex; justify-content: center; align-items: center;
  z-index: 10; border-radius: 0 3px 3px 0;
  box-shadow: inset 20px 0 35px rgba(0,0,0,0.2);
  transform: rotateZ(0.5deg);
  background-image: 
    url("https://www.transparenttextures.com/patterns/paper-fibers.png"),
    linear-gradient(to right, rgba(0,0,0,0) 80%, rgba(0,0,0,0.03) 100%),
    linear-gradient(90deg, transparent 20%, rgba(255,255,255,0.3) 25%, transparent 30%);
}

.door-text { text-align: center; border-top: 0.5px solid rgba(90, 64, 50, 0.2); border-bottom: 0.5px solid rgba(90, 64, 50, 0.2); padding: 30px 0; width: 75%; }
.welcome-main { font-family: 'Playfair Display', serif; font-size: 1.6rem; color: var(--color-main); margin: 0; letter-spacing: 0.2rem; text-transform: uppercase; opacity: 0.85; }
.welcome-sub { font-size: 0.7rem; color: var(--color-main); opacity: 0.5; margin-top: 8px; }

.pages-stack {
  width: calc(var(--book-width) - 10px); height: calc(var(--book-height) - 10px);
  position: absolute; top: 5px; left: 5px; z-index: 5;
  background: var(--color-bg); border-radius: 0 3px 3px 0;
  box-shadow: 1px 0 0 #e6e0d8, 2px 0 0 #d9d2c9, 15px 10px 30px rgba(0,0,0,0.1);
}

/* --- 下部UI (PCのデフォルト位置) --- */
.bottom-ui {
  position: absolute; bottom: 40px; right: 40px; text-align: right;
}
.loader-wrap { color: var(--color-main); font-family: serif; font-size: 1.5rem; }
.progress-bar-container { width: 120px; height: 2px; background: #eee; margin: 8px 0; overflow: hidden; display: inline-block; }
#progress-bar { width: 0%; height: 100%; background: var(--color-accent); transition: width 0.1s; }
#skip-btn { display: block; margin-left: auto; background: transparent; border: 1px solid var(--color-accent); color: var(--color-main); padding: 4px 12px; cursor: pointer; border-radius: 20px; font-size: 0.8rem; }

/* --- 【スマホ用の設定：上書き】 --- */
@media (max-width: 600px) {
  .book {
    /* スマホ用の角度に上書き */
    transform: rotateX(10deg) rotateY(-5deg);
    /* スマホ用のアニメーションを適用 */
    animation: pageFloatMobile 4s ease-in-out infinite;
  }

  @keyframes pageFloatMobile {
    0% { transform: rotateX(10deg) rotateY(-5deg); }
    50% { transform: rotateX(11deg) rotateY(-4deg); }
    100% { transform: rotateX(10deg) rotateY(-5deg); }
  }
  
  .book-container { transform: scale(0.75); }

  .bottom-ui {
    right: 50%; transform: translateX(50%); text-align: center; bottom: 30px; width: 100%;
  }
  .progress-bar-container { margin: 8px auto; }
  #skip-btn { margin: 10px auto; }
  .welcome-main { font-size: 1.4rem; }
}

.cover-unit, .cover-front, .cover-back {
  backface-visibility: hidden;
  -webkit-font-smoothing: antialiased;
}