:root {
  --sky-main: #a7d8de;
  --sky-pale: #e3f2f4;
  --ethereal-white: #f9fbfc;
  --text-charcoal: #2c3e50;
  --soft-grey: #8ea4ab;
  --glass-white: rgba(255, 255, 255, 0.4); 
  --glass-blur: 8px;
  --accent-blue: #7bbcc5;
}

* { margin: 0; padding: 0; box-sizing: border-box; scroll-behavior: smooth; }

body {
  color: var(--text-charcoal);
  font-family: 'Shippori Mincho', serif;
  line-height: 2;
  min-height: 250vh;
  background: linear-gradient(to top, var(--sky-main) 0%, var(--sky-pale) 40%, var(--ethereal-white) 100%);
  background-attachment: fixed;
  overflow-x: hidden;
}

#canvas-back { position: fixed; top: 0; left: 0; width: 100%; height: 100%; z-index: 1; pointer-events: none; }
#canvas-front { position: fixed; top: 0; left: 0; width: 100%; height: 100%; z-index: 10001; pointer-events: none; }

/* 2. リンクホバー下線（太さを文字サイズ依存に変更） */
a {
  text-decoration: none;
  color: inherit;
  position: relative;
  padding-bottom: 0.1em; /* 文字サイズに比例した余白 */
  transition: color 0.3s, opacity 0.3s;
}

a::after {
  content: '';
  position: absolute;
  bottom: 0;
  left: 0;
  width: 0;
  /* 太さを 0.05em (文字の約5%) に設定し、文字サイズに依存させる */
  height: 0.05em; 
  background: var(--text-charcoal);
  transition: width 0.4s cubic-bezier(0.25, 0.46, 0.45, 0.94);
}

a:hover::after {
  width: 100%;
}

.container {
  position: relative; z-index: 10;
  width: clamp(320px, 90%, 850px);
  margin: 0 auto; padding: 180px 0 100px;
}

.container header {
  text-align: center;
   margin-bottom: 120px;
}

/* 1. コンテナホバー演出 & 3. 表示遅延 */
.glass-block {
  background: var(--glass-white);
  backdrop-filter: blur(var(--glass-blur));
  padding: clamp(30px, 6vw, 60px); 
  margin-bottom: 80px;
  border-radius: 12px; 
  border: 1px solid rgba(255, 255, 255, 0.2);
  box-shadow: 0 4px 20px rgba(0, 0, 0, 0.03);
  opacity: 0;
  transform: translateY(40px);
  transition: opacity 1.2s ease, transform 1.2s cubic-bezier(0.16, 1, 0.3, 1), background 0.5s ease, box-shadow 0.5s ease;
}

.glass-block.is-visible {
  opacity: 1;
  transform: translateY(0);
}

.glass-block:hover {
  background: rgba(255, 255, 255, 0.6);
  transform: translateY(-8px);
  box-shadow: 0 15px 45px rgba(0, 0, 0, 0.05);
  border-color: rgba(255, 255, 255, 0.5);
}