body {
  margin: 0;
  min-height: 100vh;
  background-image:
    /* 柔らかな色むら */
    radial-gradient(circle at 30% 20%, rgba(255, 255, 255, 0.041), rgba(245, 245, 240, 0.096) 60%, rgba(240, 240, 235, 0.11)),
    /* 和紙の繊維っぽいノイズ */
    repeating-linear-gradient(45deg, rgba(1, 146, 190, 0.103) 0 1px, transparent 1px 3px),
    repeating-linear-gradient(-45deg, rgba(4, 116, 190, 0.082) 0 1px, transparent 1px 3px);
  background-blend-mode: multiply;
  background-size: cover, 4px 4px, 4px 4px;
  color: #333;
  font-family: "Yu Mincho", "Hiragino Mincho ProN", serif;
  line-height: 1.8;
  overflow-x: hidden;
  position: relative;
}

/* 波打つような陰影 */
body::before {
  content: "";
  position: fixed;
  inset: 0;
  pointer-events: none;
  background:
    linear-gradient(180deg, rgba(255,255,255,0.6), rgba(0,0,0,0.05) 60%, rgba(255,255,255,0.3));
  background-size: 100% 300%;
  mix-blend-mode: multiply;
  animation: washiWave 12s ease-in-out infinite alternate;
  opacity: 0.8;
}

@keyframes washiWave {
  0% { background-position: 0 0; }
  100% { background-position: 0 100%; }
}