* {
  box-sizing: border-box;
}

body {
  margin: 0;
  min-height: 100vh;
  background:
    linear-gradient(rgba(23, 13, 34, 0.72), rgba(23, 13, 34, 0.9)),
    url("../img/bg/top-main.jpg") center / cover fixed;
  color: #fff;
  font-family: "Yu Gothic", "Meiryo", sans-serif;
}

.history-page {
  width: min(900px, calc(100% - 32px));
  margin: 0 auto;
  padding: 48px 0;
}

.history-window {
  padding: 28px;
  border: 2px solid #d99bd0;
  border-radius: 14px;
  background: rgba(20, 10, 30, 0.86);
  box-shadow: 0 0 28px rgba(255, 160, 220, 0.2);
  backdrop-filter: blur(8px);
}

.history-header {
  margin-bottom: 24px;
  text-align: center;
}

.history-header h1 {
  margin: 0 0 10px;
  color: #ffc5ec;
  font-size: 32px;
  text-shadow: 0 0 10px rgba(255, 180, 230, 0.6);
}

.history-header p {
  margin: 0;
  line-height: 1.7;
}

.history-year {
  border: 1px solid rgba(255, 190, 230, 0.45);
  border-radius: 10px;
  background: rgba(255, 210, 240, 0.06);
  overflow: hidden;
}

.history-year summary {
  padding: 14px 18px;
  color: #ffc5ec;
  font-size: 18px;
  font-weight: bold;
  cursor: pointer;
  user-select: none;
}

.history-content {
  padding: 6px 20px 14px;
  border-top: 1px solid rgba(255, 190, 230, 0.25);
}

.history-content p {
  margin: 10px 0;
  line-height: 1.65;
}

.history-nav {
  margin-top: 24px;
  text-align: center;
}

.history-nav a {
  display: inline-block;
  padding: 10px 18px;
  border: 1px solid rgba(255, 190, 230, 0.55);
  border-radius: 8px;
  background: rgba(255, 210, 240, 0.08);
  color: #fff;
  text-decoration: none;
  font-weight: bold;
}

.history-nav a:hover {
  background: rgba(255, 170, 220, 0.25);
}

@media (max-width: 600px) {
  .history-page {
    width: min(100% - 20px, 900px);
    padding: 18px 0;
  }

  .history-window {
    padding: 18px;
  }

  .history-header h1 {
    font-size: 26px;
  }

  .history-year summary {
    padding: 12px 14px;
  }

  .history-content {
    padding: 4px 14px 12px;
    font-size: 14px;
  }
}