/**
 * File: topnav.css
 * Purpose: 固定ページ「トップナビサンプル」専用のヘッダースタイル
 * Author: Miura Keiko
 * Last updated: 2025-04-21
 */

/* 全体構造 */
.topnav-header {
  position: relative;
  width: 100%;
  z-index: 1000;
  transition: all 0.3s ease;
  display: flex;
  justify-content: space-between;
  align-items: center;
  padding: 10px 20px;
  box-sizing: border-box;
  min-height: 70px;
  overflow-x: hidden;
}

/* 固定されたときのスタイル（透過背景） */
.topnav-header.fixed {
  position: fixed;
  top: 0;
  left: 0;
  background-color: rgba(255, 255, 255, 0.8);
  box-shadow: 0 2px 5px rgba(0, 0, 0, 0.1);
}

/* ロゴ */
.logo {
  font-size: 1.5rem;
  font-weight: bold;
  white-space: nowrap;
}

/* PCボタンエリア */
.pc-buttons {
  display: flex;
  gap: 10px;
}

.pc-buttons button {
  width: 240px;
  padding: 10px;
  background-color: #0073aa;
  color: white;
  border: none;
  border-radius: 5px;
  font-size: 1rem;
}

/* スマホ用メニュー */
.sp-header {
  display: none;
  gap: 10px;
}

.sp-header button {
  background-color: #00aa77;
  color: white;
  border: none;
  border-radius: 5px;
  width: 180px;
  height: 50px;
  font-size: 1.1rem;
  display: flex;
  align-items: center;
  justify-content: center;
}

.toggle-menu {
  width: 50px;
  height: 50px;
  font-size: 1.5rem;
  background-color: #555;
  color: white;
  border-radius: 5px;
  display: flex;
  align-items: center;
  justify-content: center;
}


/* ✅ 修正済み：画面幅いっぱい背景にするための navtextbox */
.navtextbox {
  height: 2000px;
  background: skyblue;
  width: 100vw;
  position: relative;
  left: 50%;
  margin-left: -50vw;
  box-sizing: border-box;
}


/* レスポンシブ切り替え */
@media screen and (max-width: 767px) {
  .pc-buttons {
    display: none;
  }
  .sp-header {
    display: flex;
    align-items: center;
  }

  .topnav-header {
    flex-wrap: nowrap;
    padding: 10px 15px;
  }
}
.back-to-toc {
  display: block !important;
  text-align: center;
  margin: 60px 0;
}

.btn-common {
  display: inline-block !important;
  opacity: 1 !important;
  visibility: visible !important;
  background-color: #333 !important;
  color: #fff !important;
  padding: 8px 20px;
  font-size: 13px;
  border-radius: 5px;
  text-decoration: none;
  z-index: 9999;
  position: relative;
}