body {
  margin: 0;
  background-color: #111;
  color: #fff;
  font-family: "Segoe UI", Arial, sans-serif;
  text-align: center;
}

header, footer {
  margin: 10px 0;
}

/* レイアウト：左右広告 + 中央時計 */
.container {
  display: flex;
  justify-content: center;
  align-items: flex-start;
  margin: 0 auto;
}

/* 広告 */
.ad {
  width: 160px;
  height: 600px;
  margin: 0 10px;
}

/* 中央メイン */
main {
  flex: 1;
  display: flex;
  justify-content: center;
  align-items: center;
}

/* 時計Canvas */
canvas {
  max-width: 80vw;
  max-height: 80vh;
  border-radius: 50%;
  background: radial-gradient(circle at center, #222 0%, #000 100%);
  box-shadow: 0 0 30px rgba(255, 255, 255, 0.2) inset;
}