@charset "UTF-8";
body {
  font-family: "Noto Sans JP", sans-serif;
  color: #231815;
}

.text_serif {
  font-family: "Noto Serif JP", serif;
}

/*---------------------------
basic setting
---------------------------*/
@media screen and (min-width: 769px) {
  .sp {
    display: none !important;
  }
}
@media screen and (max-width: 768px) {
  .pc {
    display: none !important;
  }
}
/*ボックスサイジング ボーダーボックス*/
*, *:before, *:after {
  -webkit-box-sizing: border-box;
  -moz-box-sizing: border-box;
  -o-box-sizing: border-box;
  -ms-box-sizing: border-box;
  box-sizing: border-box;
}

.text {
  color: #231815;
  font-size: 1rem;
  font-weight: 400;
  line-height: 1.5;
}

.justify_text {
  text-align: justify;
  text-justify: inter-ideograph;
}
@media all and (-ms-high-contrast: none) {
  .justify_text {
    font-feature-settings: normal;
  }
}

body {
  color: #231815;
}

a,
a:link,
a:visited {
  color: #231815;
  text-decoration: none;
}

a:hover {
  opacity: 0.8;
  transition: all 0.8s;
}

#backToTop {
  position: fixed;
  right: 20px;
  bottom: 20px;
  width: 60px;
  height: 60px;
  background: #111;
  border-radius: 14px;
  display: flex;
  justify-content: center;
  align-items: center;
  cursor: pointer;
  opacity: 0;
  visibility: hidden;
  transition: opacity 0.3s ease, visibility 0.3s ease;
  box-shadow: 0 4px 12px rgba(0, 0, 0, 0.3);
}
@media (max-width: 768px) {
  #backToTop {
    right: 3vw;
    bottom: 3vw;
    width: 10vw;
    height: 10vw;
  }
}
#backToTop {
  /* ▼ 矢印は画像で表示 */
}
#backToTop .arrow {
  width: 30px;
  height: 30px;
  background-image: url("../img/arrow.png");
  background-size: contain;
  background-repeat: no-repeat;
  background-position: center;
}
@media (max-width: 768px) {
  #backToTop .arrow {
    width: 7vw;
    height: 7vw;
  }
}
#backToTop:hover {
  background: #222;
}

/* ▼ スクロール後に表示 */
#backToTop.show {
  opacity: 1;
  visibility: visible;
}

/*---------------------------
sec
---------------------------*/
.sec {
  width: 100%;
  max-width: 900px;
  margin: 0 auto;
}
@media (max-width: 768px) {
  .sec {
    width: 100%;
  }
}

header {
  position: fixed; /* ← 上部固定のまま */
  top: 0;
  left: 0;
  width: 100%;
  background-color: #fff;
  z-index: 999;
  box-shadow: 0 2px 6px rgba(0, 0, 0, 0.15);
  /* ☆ header は fixed のままなので絶対に relative を上書きしない */
}
header .header__inner {
  position: relative; /* ← hamburger の absolute の基準はこっちにする */
  display: flex;
  justify-content: flex-start;
  align-items: center;
  padding: 1.5em;
}
@media (max-width: 768px) {
  header .header__inner {
    padding: 4vw 5vw;
  }
}
header .header__inner h1 a img {
  width: clamp(400px, 30%, 600px);
}
@media (max-width: 768px) {
  header .header__inner h1 a img {
    width: clamp(200px, 60%, 400px);
  }
}
header {
  /* ▼▼ drop-nav（完全再現版） ▼▼ */
}
header .drop-nav {
  position: absolute;
  top: 100%;
  left: 0;
  width: 100%;
  background: rgba(255, 255, 255, 0.95);
  text-align: center;
  overflow: hidden;
  max-height: 0;
  opacity: 0;
  transition: max-height 0.5s ease, opacity 0.3s ease;
  /* PC & SP 共通 */
}
header .drop-nav ul {
  padding: 50px 0; /* 上下余白が大きい */
  margin: 0;
}
header .drop-nav ul li {
  list-style: none;
  margin: 22px 0; /* 行ごとの余白 */
}
header .drop-nav ul li a {
  color: #c40000;
  font-size: 24px; /* PCの基準 */
  font-weight: 700; /* 太文字 */
  letter-spacing: 0.05em; /* ほんのり広め */
  text-decoration: none;
  display: inline-block;
}
header .drop-nav {
  /* --- 展開時 --- */
}
header .drop-nav.active {
  max-height: 600px; /* 余裕を持たせる */
  opacity: 1;
}
header .drop-nav {
  /* SP 調整（スマホ時の縮小） */
}
@media (max-width: 768px) {
  header .drop-nav ul {
    padding: 20px 0;
  }
  header .drop-nav ul li a {
    font-size: 20px;
    letter-spacing: 0.04em;
  }
}
header .hamburger {
  position: absolute;
  top: 50%;
  right: 30px;
  transform: translateY(-50%);
  width: 40px;
  height: 30px;
  background: none;
  cursor: pointer;
  z-index: 1001;
  border: none;
}
@media (max-width: 768px) {
  header .hamburger {
    width: 28px;
    height: 22px;
  }
}
header .hamburger span {
  position: absolute;
  top: 50%;
  left: 0;
  width: 100%;
  height: 3px;
  background: #000;
  transition: 0.3s ease;
  transform-origin: center;
}
@media (max-width: 768px) {
  header .hamburger span {
    height: 2px;
  }
}
header .hamburger span {
  /* PC用初期位置 */
}
header .hamburger span:nth-child(1) {
  transform: translateY(-13px);
}
header .hamburger span:nth-child(2) {
  transform: translateY(0);
}
header .hamburger span:nth-child(3) {
  transform: translateY(13px);
}
header .hamburger span {
  /* SP用初期位置 */
}
@media (max-width: 768px) {
  header .hamburger span:nth-child(1) {
    transform: translateY(-9px);
  }
  header .hamburger span:nth-child(2) {
    transform: translateY(0);
  }
  header .hamburger span:nth-child(3) {
    transform: translateY(9px);
  }
}
header .hamburger.active span:nth-child(1) {
  transform: translateY(0) rotate(45deg);
}
header .hamburger.active span:nth-child(2) {
  opacity: 0;
}
header .hamburger.active span:nth-child(3) {
  transform: translateY(0) rotate(-45deg);
}

/*---------------------------
共通 footer
---------------------------*/
/*404ページ*/
.error404 h2 {
  margin-top: 100px;
  font-size: 2rem;
  text-align: center;
}
.error404 .text {
  margin-top: 100px;
  text-align: center;
}
.error404 .btn {
  margin-bottom: 150px;
}