@charset "utf-8";

/* =========================================================
   大町流鏑馬太鼓 — スタイルシート
   見出し: Shippori Antique B1 / 本文・メニュー: デバイスフォント
   ========================================================= */

:root {
  --c-ink: #1F1A2C;
  --c-murasaki: #5A3D8A;
  --c-murasaki-deep: #33235A;
  --c-shu: #C8442E;
  --c-shu-light: #e06a52;
  --c-kin: #C0A24C;
  --c-washi: #F7F4EE;
  --c-washi-alt: #EFEBE2;
  --c-white: #FFFFFF;
  --c-sumi: #4A4550;

  --maxw: 1080px;
  --maxw-read: 780px;

  /* 全体を游ゴシック（Yu Gothic）に統一 */
  --font-yugo: "Yu Gothic Medium", "Yu Gothic", YuGothic, "游ゴシック体", "游ゴシック",
    "Hiragino Kaku Gothic ProN", "ヒラギノ角ゴ ProN", Meiryo, "メイリオ", sans-serif;
  --font-head: var(--font-yugo);
  --font-body: var(--font-yugo);

  --header-h: 68px;
  --ease: cubic-bezier(0.22, 1, 0.36, 1);
  /* 全セクション共通の上下余白（統一） */
  --section-pad: clamp(4.5rem, 8vw, 7rem);
}

/* reset補完 */
* { box-sizing: border-box; }
html {
  scroll-behavior: smooth;
  scroll-padding-top: var(--header-h);
  -webkit-text-size-adjust: 100%;
}
body {
  margin: 0;
  font-family: var(--font-body);
  color: var(--c-ink);
  background: var(--c-washi);
  line-height: 1.9;
  letter-spacing: 0.02em;
  font-size: 16px;
  overflow-x: hidden;
}
img { max-width: 100%; height: auto; display: block; }
a { color: var(--c-shu); text-decoration: none; transition: opacity .3s, color .3s; }
a:hover { opacity: .82; }

h1, h2, h3, h4 { font-family: var(--font-head); font-weight: 700; line-height: 1.4; }

/* 見出し・表示系要素は游ゴシックの太字で存在感を出す */
.brand-text, .mv-sub, .mv-title, .section-label, .section-title,
.stat-num, .history-catch, .history-kanji, .history-continue,
.tl-year, .tl-lead, .era-badge, .song-name, .qa-q, .minor-title,
.contact-org, .footer-brand { font-weight: 700; }

/* =========================================================
   ヘッダー
   ========================================================= */
.site-header {
  position: sticky;
  top: 0;
  z-index: 100;
  background: rgba(247, 244, 238, 0.72);
  backdrop-filter: blur(10px);
  -webkit-backdrop-filter: blur(10px);
  transition: background .35s, box-shadow .35s;
}
.site-header.scrolled {
  background: rgba(247, 244, 238, 0.96);
  box-shadow: 0 2px 20px rgba(31, 26, 44, 0.08);
}
.header-inner {
  max-width: 1240px;
  margin: 0 auto;
  height: var(--header-h);
  padding: 0 clamp(1rem, 4vw, 2.5rem);
  display: flex;
  align-items: center;
  justify-content: space-between;
}
.brand { display: flex; align-items: center; gap: .6rem; opacity: 1; }
.brand-wordmark { height: 40px; width: auto; display: block; }
.brand-fallback { display: none; align-items: center; gap: .6rem; }
.brand-fallback.show { display: flex; }
.brand-logo { width: 40px; height: 40px; object-fit: contain; }
.brand-text {
  font-family: var(--font-head);
  color: var(--c-ink);
  font-size: 1.15rem;
  letter-spacing: 0.08em;
}
.nav { display: flex; align-items: center; gap: clamp(1rem, 2vw, 1.9rem); }
.nav-link {
  position: relative;
  color: var(--c-ink);
  font-size: .92rem;
  letter-spacing: .04em;
  padding: .3rem 0;
}
.nav-link::after {
  content: "";
  position: absolute; left: 0; bottom: -2px;
  width: 100%; height: 2px;
  background: var(--c-shu);
  transform: scaleX(0); transform-origin: left;
  transition: transform .3s var(--ease);
}
.nav-link:hover { opacity: 1; }
.nav-link:hover::after,
.nav-link.active::after { transform: scaleX(1); }
.nav-sns { display: flex; gap: .7rem; margin-left: .4rem; }
.nav-sns a { color: var(--c-murasaki); display: inline-flex; }
.nav-sns a:hover { color: var(--c-shu); opacity: 1; }

/* ハンバーガー */
.hamburger {
  display: none;
  flex-direction: column; justify-content: center; gap: 5px;
  width: 44px; height: 44px;
  background: none; border: none; cursor: pointer; padding: 0;
}
.hamburger span {
  display: block; width: 26px; height: 2px; margin: 0 auto;
  background: var(--c-ink); transition: transform .35s var(--ease), opacity .25s;
}
.hamburger.open span:nth-child(1) { transform: translateY(7px) rotate(45deg); }
.hamburger.open span:nth-child(2) { opacity: 0; }
.hamburger.open span:nth-child(3) { transform: translateY(-7px) rotate(-45deg); }

/* =========================================================
   MV（ヒーロー）
   ========================================================= */
.mv {
  position: relative;
  height: 100svh;
  min-height: 560px;
  display: flex;
  align-items: center;
  overflow: hidden;
  color: var(--c-white);
}
.mv-slides { position: absolute; inset: 0; z-index: 0; }
.mv-slide {
  position: absolute; inset: 0;
  background-size: cover;
  background-position: center;
  opacity: 0;
  transform: scale(1.08);
  transition: opacity 1.6s ease, transform 7s ease;
}
.mv-slide.is-active { opacity: 1; transform: scale(1); }
.mv-overlay {
  position: absolute; inset: 0; z-index: 1;
  /* 写真本来の色を活かす中立的な暗さ（紫の被りを除去）。文字可読性は左下に軽い暗がりで確保 */
  background:
    linear-gradient(180deg, rgba(0,0,0,.30) 0%, rgba(0,0,0,.10) 42%, rgba(0,0,0,.48) 100%),
    linear-gradient(90deg, rgba(0,0,0,.42) 0%, rgba(0,0,0,.12) 52%, rgba(0,0,0,0) 100%);
}
.mv-copy {
  position: relative; z-index: 2;
  max-width: var(--maxw);
  width: 100%;
  margin: 0 auto;
  padding: 0 clamp(1.4rem, 5vw, 3rem);
}
.mv-sub {
  font-family: var(--font-head);
  letter-spacing: .28em;
  font-size: .8rem;
  margin: 0 0 1rem;
  opacity: .9;
}
.mv-title {
  font-family: var(--font-head);
  font-size: clamp(2rem, 6vw, 3.6rem);
  line-height: 1.5;
  letter-spacing: .06em;
  margin: 0;
  text-shadow: 0 2px 24px rgba(0,0,0,.35);
}
.mv-lead {
  margin: 1.4rem 0 2rem;
  font-size: clamp(.95rem, 1.5vw, 1.15rem);
  text-shadow: 0 1px 12px rgba(0,0,0,.4);
  max-width: 30em;
}
.sp-br { display: none; }
.mv-dots {
  position: absolute; z-index: 3;
  bottom: 2rem; left: 50%; transform: translateX(-50%);
  display: flex; gap: .6rem;
}
.mv-dots button {
  width: 10px; height: 10px; border-radius: 50%;
  border: none; background: rgba(255,255,255,.45); cursor: pointer; padding: 0;
  transition: background .3s, transform .3s;
}
.mv-dots button.active { background: var(--c-white); transform: scale(1.25); }

/* =========================================================
   セクション共通
   ========================================================= */
/* main をフレックス化し、Instagram を MV 直下（最上部）に表示 */
main { display: flex; flex-direction: column; }
#instagram { order: -1; }

.section { padding: var(--section-pad) 0; }
.container { max-width: var(--maxw); margin: 0 auto; padding: 0 clamp(1.4rem, 5vw, 3rem); }
.section .container { position: relative; }

/* マスコットキャラクター（画像を置くと自動表示・無ければ非表示） */
.chara {
  position: absolute;
  z-index: 3;
  width: clamp(120px, 15vw, 210px);
  height: auto;
  pointer-events: none;
  filter: drop-shadow(0 12px 22px rgba(51, 35, 90, .22));
  animation: charaFloat 4s ease-in-out infinite;
}
.chara-yabusame { top: -1rem; right: clamp(.5rem, 2vw, 1rem); }
.chara-taiko { top: -.5rem; right: clamp(.5rem, 2vw, 1rem); width: clamp(130px, 16vw, 230px); }
@keyframes charaFloat { 0%,100% { transform: translateY(0); } 50% { transform: translateY(-8px); } }
@media (max-width: 860px) {
  .chara { width: 92px; top: -.5rem; right: .4rem; }
  .chara-taiko { width: 104px; }
}
@media (prefers-reduced-motion: reduce) { .chara { animation: none; } }

.section-light { background: var(--c-washi); color: var(--c-ink); }
.section-washi-alt { background: var(--c-washi-alt); color: var(--c-ink); }
.section-deep { background: var(--c-murasaki-deep); color: var(--c-white); }

.section-head { margin-bottom: clamp(2.2rem, 4vw, 3rem); }
.section-label {
  display: block;
  font-family: var(--font-head);
  font-size: .78rem;
  letter-spacing: .3em;
  color: var(--c-shu);
  margin-bottom: .6rem;
}
.section-title {
  font-size: clamp(1.7rem, 4vw, 2.5rem);
  letter-spacing: .06em;
  margin: 0;
}
.section-rule {
  display: block; width: 56px; height: 3px;
  background: var(--c-kin); margin-top: 1.1rem; border-radius: 2px;
}
.section-head-light .section-label { color: var(--c-kin); }
.section-head-light .section-title { color: var(--c-white); }

.lead-copy {
  max-width: var(--maxw-read);
  font-size: clamp(1rem, 1.5vw, 1.12rem);
  margin: 0 0 2.6rem;
}
.lead-light { color: rgba(255,255,255,.92); }
.minor-title {
  font-family: var(--font-head);
  font-size: 1.2rem;
  letter-spacing: .04em;
  color: var(--c-murasaki);
  margin: 2rem 0 .8rem;
  padding-left: .7rem;
  border-left: 4px solid var(--c-kin);
}
.minor-title-light { color: var(--c-white); }
strong { font-weight: 700; color: inherit; }

/* =========================================================
   古事・由来 インフォグラフィック
   ========================================================= */
.stat-grid {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 1rem;
  margin: 0 0 3.5rem;
}
.stat {
  background: var(--c-white);
  border-radius: 14px;
  padding: 1.8rem 1rem;
  text-align: center;
  box-shadow: 0 8px 30px rgba(51,35,90,.06);
  border-top: 3px solid var(--c-kin);
}
.stat-icon {
  display: flex;
  align-items: center;
  justify-content: center;
  width: 52px;
  height: 52px;
  margin: 0 auto .9rem;
  color: var(--c-kin);
}
.stat-icon svg { width: 100%; height: 100%; }
.stat-num {
  display: block;
  font-family: var(--font-head);
  font-size: clamp(1.8rem, 4vw, 2.6rem);
  color: var(--c-murasaki);
  line-height: 1.1;
}
.stat-unit { font-size: .5em; margin-left: .1em; }
.stat-label {
  display: block;
  font-size: .82rem;
  color: var(--c-sumi);
  margin-top: .7rem;
  line-height: 1.5;
}
.origin-body { display: block; }
/* 本文は全幅を活かしつつ2カラムで1行を読みやすく */
.origin-grid {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: clamp(1.6rem, 4vw, 3.5rem);
}
.origin-col .minor-title:first-child { margin-top: 0; }
.origin-text p { margin: 0 0 1.1rem; }
@media (max-width: 820px) {
  .origin-grid { grid-template-columns: 1fr; gap: 0; }
}

/* 全幅イメージバンド（各セクションで写真を活用） */
.photo-band { margin: clamp(2rem, 5vw, 3.4rem) 0 0; }
.photo-band img {
  width: 100%;
  height: clamp(220px, 40vw, 440px);
  object-fit: cover;
  border-radius: 16px;
  box-shadow: 0 14px 42px rgba(51, 35, 90, .16);
  display: block;
}
.photo-band figcaption {
  text-align: center; font-size: .82rem; color: var(--c-sumi); margin-top: .7rem;
}
.section-deep .photo-band figcaption { color: rgba(255, 255, 255, .75); }
.photo-band-lead { margin-bottom: clamp(2rem, 5vw, 3.4rem); margin-top: 0; }

/* =========================================================
   歴史 タイムライン インフォグラフィック「道」
   ========================================================= */
.history-catch {
  text-align: center; color: var(--c-kin);
  font-family: var(--font-head); letter-spacing: .12em;
  margin: 0; font-size: clamp(.95rem, 2vw, 1.2rem);
}
.history-kanji {
  text-align: center; font-family: var(--font-head);
  font-size: clamp(4rem, 14vw, 8rem); line-height: 1;
  margin: .3rem 0 2.5rem; color: rgba(255,255,255,.9);
  text-shadow: 0 6px 30px rgba(0,0,0,.25);
}
.timeline {
  position: relative;
  max-width: 760px;
  margin: 0 auto;
  padding-left: 2rem;
}
/* 縦の「道」ライン（矢の軸） */
.timeline::before {
  content: "";
  position: absolute; left: 7px; top: 4px; bottom: 4px;
  width: 3px;
  background: linear-gradient(180deg, var(--c-kin), rgba(192,162,76,.35));
}
.era-badge {
  display: inline-block;
  font-family: var(--font-head);
  background: var(--c-shu);
  color: #fff;
  padding: .35rem 1.1rem;
  border-radius: 999px;
  letter-spacing: .12em;
  font-size: 1rem;
  margin: 2.2rem 0 1.2rem -2rem;
  position: relative;
  box-shadow: 0 6px 18px rgba(200,68,46,.3);
}
.era-badge:first-child { margin-top: 0; }
.tl-item {
  position: relative;
  display: grid;
  grid-template-columns: 64px 1fr;
  gap: 1rem;
  align-items: start;
  margin-bottom: 1rem;
}
.tl-item::before {
  content: "";
  position: absolute; left: -2rem; top: 8px;
  width: 15px; height: 15px; border-radius: 50%;
  background: var(--c-kin);
  border: 3px solid var(--c-murasaki-deep);
  box-shadow: 0 0 0 2px var(--c-kin);
  transform: translateX(-1px);
}
.tl-year {
  font-family: var(--font-head);
  color: var(--c-kin);
  font-size: 1.05rem;
  padding-top: 2px;
  letter-spacing: .04em;
  white-space: nowrap;
}
.tl-card {
  background: rgba(255,255,255,.07);
  border: 1px solid rgba(255,255,255,.12);
  border-radius: 10px;
  padding: .8rem 1.1rem;
}
.tl-card p { margin: 0; font-size: .92rem; color: rgba(255,255,255,.92); }
.tl-card .tl-lead {
  font-family: var(--font-head); font-size: 1.05rem; color: #fff; letter-spacing: .04em;
}
.history-continue {
  text-align: center;
  font-family: var(--font-head);
  color: var(--c-kin);
  letter-spacing: .12em;
  font-size: clamp(1.1rem, 2.5vw, 1.5rem);
  margin: 2.5rem 0 0;
}

/* =========================================================
   曲目紹介
   ========================================================= */
.song-grid {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: 1.4rem;
}
.song-card {
  background: var(--c-white);
  border-radius: 14px;
  padding: 1.8rem;
  box-shadow: 0 8px 30px rgba(51,35,90,.06);
  border-left: 4px solid var(--c-murasaki);
  transition: transform .4s var(--ease), box-shadow .4s;
}
.song-card:hover { transform: translateY(-4px); box-shadow: 0 16px 44px rgba(51,35,90,.12); }
.song-card-head {
  display: flex; align-items: baseline; justify-content: space-between;
  gap: .8rem; margin-bottom: .9rem; flex-wrap: wrap;
}
.song-name {
  font-size: 1.4rem; letter-spacing: .06em; margin: 0; color: var(--c-ink);
}
.song-yomi {
  font-family: var(--font-body); font-size: .72rem; color: var(--c-sumi);
  margin-left: .5rem; letter-spacing: .08em;
}
.song-player {
  font-family: var(--font-body); font-size: .74rem;
  background: var(--c-washi-alt); color: var(--c-murasaki);
  padding: .2rem .8rem; border-radius: 999px; white-space: nowrap;
}
.song-card p { margin: 0 0 .6rem; font-size: .92rem; }
.shigin {
  margin: .8rem 0; padding: 1rem 1.2rem;
  background: var(--c-washi); border-radius: 8px;
  font-family: var(--font-head); letter-spacing: .06em;
  color: var(--c-murasaki-deep); line-height: 2; font-size: .95rem;
}

/* =========================================================
   メンバー募集
   ========================================================= */
.member-layout {
  display: grid; grid-template-columns: 1.5fr 1fr;
  gap: clamp(1.5rem, 4vw, 3rem); align-items: start;
}
.qa { margin-bottom: 1.6rem; }
.qa-q {
  font-family: var(--font-head); font-size: 1.15rem;
  color: var(--c-murasaki); margin: 0 0 .5rem;
  position: relative; padding-left: 1.6rem; letter-spacing: .03em;
}
.qa-q::before {
  content: "○"; position: absolute; left: 0; top: 0;
  color: var(--c-shu); font-size: 1rem;
}
.qa-a { margin: 0; font-size: .95rem; padding-left: 1.6rem; }
.member-aside {
  position: sticky; top: calc(var(--header-h) + 1.5rem);
  display: flex; flex-direction: column; gap: 1.4rem;
}
.member-figure { margin: 0; }
.member-figure img {
  width: 100%; height: auto;
  border-radius: 14px; box-shadow: 0 12px 36px rgba(51,35,90,.14);
}
/* 見学・入会CTA：コンテンツ幅の中央に配置 */
.member-cta { text-align: center; margin-top: clamp(2.4rem, 5vw, 3.4rem); }

/* 3枚並びの写真ロウ（活動の様子） */
.photo-row {
  display: grid; grid-template-columns: repeat(3, 1fr); gap: 1rem;
  margin-bottom: clamp(2rem, 5vw, 3rem);
}
.photo-row figure { margin: 0; }
.photo-row img {
  width: 100%; height: clamp(150px, 18vw, 240px); object-fit: cover;
  border-radius: 12px; box-shadow: 0 12px 34px rgba(0, 0, 0, .18);
}

/* =========================================================
   出演依頼
   ========================================================= */
.request-grid {
  display: grid; grid-template-columns: repeat(2, 1fr);
  gap: 1.4rem; margin-bottom: 2.5rem;
}
.request-card {
  background: rgba(255,255,255,.07);
  border: 1px solid rgba(255,255,255,.14);
  border-radius: 14px; padding: 1.8rem;
}
.request-card p { margin: 0; color: rgba(255,255,255,.9); font-size: .95rem; }
.request-cta { text-align: center; }

/* =========================================================
   Instagram
   ========================================================= */
.ig-grid {
  display: grid; grid-template-columns: repeat(6, 1fr); gap: .8rem;
}
.ig-item {
  position: relative; display: block; aspect-ratio: 1 / 1;
  border-radius: 12px; overflow: hidden; opacity: 1;
}
.ig-item img {
  width: 100%; height: 100%; object-fit: cover;
  transition: transform .5s var(--ease);
}
.ig-item:hover img { transform: scale(1.08); }
.ig-hover {
  position: absolute; inset: 0;
  display: flex; align-items: center; justify-content: center;
  color: #fff; background: rgba(51,35,90,.0);
  opacity: 0; transition: opacity .35s, background .35s;
}
.ig-item:hover .ig-hover { opacity: 1; background: rgba(51,35,90,.45); }
.ig-cta { text-align: center; margin-top: 2rem; }

/* =========================================================
   お問い合わせ
   ========================================================= */
/* お問い合わせは中央寄せで配置 */
.contact .section-head { text-align: center; }
.contact .section-rule { margin-left: auto; margin-right: auto; }
.contact-card {
  max-width: 640px;
  margin-left: auto;
  margin-right: auto;
  background: rgba(255,255,255,.06);
  border: 1px dashed rgba(255,255,255,.4);
  border-radius: 16px;
  padding: clamp(1.8rem, 4vw, 2.6rem);
}
.contact-org {
  font-family: var(--font-head); font-size: 1.25rem;
  color: #fff; margin: 0 0 1.5rem; letter-spacing: .04em;
}
.contact-org-sub { font-size: .85rem; color: rgba(255,255,255,.75); }
.contact-dl { margin: 0 0 1.6rem; }
.contact-dl > div {
  display: grid; grid-template-columns: 90px 1fr; gap: 1rem;
  padding: .6rem 0; border-bottom: 1px solid rgba(255,255,255,.12);
}
.contact-dl dt {
  font-size: .82rem; color: var(--c-kin); letter-spacing: .06em; margin: 0;
}
.contact-dl dd { margin: 0; font-size: .95rem; color: rgba(255,255,255,.92); }
.contact-dl a { color: #fff; text-decoration: underline; text-underline-offset: 3px; }
.contact-sns { display: flex; gap: 1rem; flex-wrap: wrap; justify-content: center; }

/* =========================================================
   ボタン
   ========================================================= */
/* ボタン：キーカラー（紫）で全種統一・従来比2倍サイズ・ホバーでキラッと光る */
.btn, .btn-outline {
  position: relative;
  overflow: hidden;
  display: inline-block;
  background: var(--c-murasaki); color: #fff;
  font-family: var(--font-body); font-weight: 700;
  font-size: 1.15rem; letter-spacing: .06em;
  padding: 1.5rem 4rem; border-radius: 999px;
  border: 1px solid rgba(255, 255, 255, .22);
  transition: transform .25s var(--ease), box-shadow .3s, background .3s;
  box-shadow: 0 12px 32px rgba(90, 61, 138, .38);
}
.btn:hover, .btn-outline:hover {
  transform: translateY(-2px); opacity: 1;
  background: #6d4bab;
  box-shadow: 0 18px 44px rgba(90, 61, 138, .5);
}
/* キラッと光るシャイン */
.btn::after, .btn-outline::after {
  content: "";
  position: absolute; top: 0; left: -85%;
  width: 55%; height: 100%;
  background: linear-gradient(120deg, transparent 0%, rgba(255, 255, 255, .65) 50%, transparent 100%);
  transform: skewX(-20deg);
  pointer-events: none;
}
.btn:hover::after, .btn-outline:hover::after { animation: btnShine .85s var(--ease); }
@keyframes btnShine { 0% { left: -85%; } 100% { left: 135%; } }

/* 背景バリエーション：濃色（色つき）背景では白地×紫文字で視認性を確保 */
.section-deep .btn, .section-deep .btn-outline {
  background: var(--c-white);
  color: var(--c-murasaki-deep);
  border-color: transparent;
  box-shadow: 0 12px 32px rgba(0, 0, 0, .30);
}
.section-deep .btn:hover, .section-deep .btn-outline:hover {
  background: #efe8ff;
  box-shadow: 0 18px 44px rgba(0, 0, 0, .38);
}
.section-deep .btn::after, .section-deep .btn-outline::after {
  background: linear-gradient(120deg, transparent 0%, rgba(90, 61, 138, .20) 50%, transparent 100%);
}

/* =========================================================
   フッター
   ========================================================= */
.site-footer {
  background: var(--c-ink); color: rgba(255,255,255,.85);
  padding: 3rem 0 2.5rem;
}
.footer-inner { text-align: center; }
.footer-brand {
  display: flex; align-items: center; justify-content: center;
  margin-bottom: 1.4rem;
}
/* ヘッダーと同じ筆文字ロゴを白抜きで表示 */
.footer-wordmark {
  height: 40px; width: auto;
  filter: brightness(0) invert(1);
  opacity: .95;
}
.footer-nav {
  display: flex; flex-wrap: wrap; justify-content: center;
  gap: .6rem 1.4rem; margin-bottom: 1.6rem;
}
.footer-nav a {
  color: rgba(255,255,255,.8); font-size: .88rem; letter-spacing: .03em;
}
.footer-nav a:hover { color: #fff; opacity: 1; }
.copyright { margin: 0; color: rgba(255,255,255,.55); }
.powered-by { margin: .5rem 0 0; }
.powered-by small { font-size: 13px; color: rgba(255,255,255,.5); }
.powered-by a { color: rgba(255,255,255,.72); text-decoration: underline; text-underline-offset: 2px; }
.powered-by a:hover { color: #fff; opacity: 1; }

/* トップへ戻る */
.to-top {
  position: fixed; right: 1.2rem; bottom: 1.2rem; z-index: 90;
  width: 48px; height: 48px; border-radius: 50%; border: none;
  background: var(--c-murasaki); color: #fff; cursor: pointer;
  display: flex; align-items: center; justify-content: center;
  box-shadow: 0 8px 24px rgba(51,35,90,.3);
  opacity: 0; visibility: hidden; transform: translateY(10px);
  transition: opacity .35s, visibility .35s, transform .35s, background .3s;
}
.to-top.show { opacity: 1; visibility: visible; transform: translateY(0); }
.to-top:hover { background: var(--c-shu); }

/* =========================================================
   スクロール演出
   ========================================================= */
.reveal { opacity: 0; transform: translateY(26px); transition: opacity .8s var(--ease), transform .8s var(--ease); }
.reveal.visible { opacity: 1; transform: none; }

/* =========================================================
   レスポンシブ
   ========================================================= */
@media (max-width: 900px) {
  .stat-grid { grid-template-columns: repeat(2, 1fr); }
  .origin-body { grid-template-columns: 1fr; }
  .origin-figure { max-width: 460px; margin: 0 auto; }
  .song-grid { grid-template-columns: 1fr; }
  .member-layout { grid-template-columns: 1fr; }
  .member-aside { position: static; }
  .request-grid { grid-template-columns: 1fr; }
  .ig-grid { grid-template-columns: repeat(3, 1fr); }
}

@media (max-width: 768px) {
  :root { --header-h: 60px; }

  /* backdrop-filter は fixed 子要素の基準を狂わせるためモバイルでは無効化 */
  .site-header, .site-header.scrolled {
    backdrop-filter: none;
    -webkit-backdrop-filter: none;
  }

  /* ナビ：全画面・ボタン式ドロワー */
  .nav {
    position: fixed;
    inset: 0;                 /* 画面全面 */
    z-index: 200;
    flex-direction: column;
    justify-content: center;
    align-items: center;
    gap: 1rem;
    background: linear-gradient(180deg, #33235A 0%, #1F1A2C 100%);
    transform: translateX(100%);
    transition: transform .4s var(--ease);
    padding: calc(var(--header-h) + 2rem) 1.5rem 2rem;
    overflow-y: auto;
  }
  .nav.open { transform: translateX(0); }
  .nav-link {
    display: block;
    width: min(84%, 340px);
    text-align: center;
    color: #fff;
    background: rgba(255, 255, 255, .08);
    border: 1px solid rgba(255, 255, 255, .3);
    border-radius: 999px;
    padding: .95rem 1.5rem;
    font-size: 1.1rem;
    letter-spacing: .04em;
  }
  .nav-link::after { display: none; }
  .nav-link:hover, .nav-link.active {
    background: var(--c-shu);
    border-color: var(--c-shu);
    opacity: 1;
  }
  .nav-sns { margin-top: 1.2rem; }
  .nav-sns a { color: #fff; }

  /* ハンバーガーは前面に固定して開閉できるように */
  .hamburger { display: flex; position: relative; z-index: 260; }
  .hamburger.open span { background: #fff; }

  .brand-text { font-size: 1rem; }
  .brand-wordmark { height: 30px; }

  .sp-br { display: inline; }
  .mv-title { line-height: 1.55; }

  .contact-dl > div { grid-template-columns: 70px 1fr; gap: .5rem; }
}

@media (max-width: 480px) {
  body { font-size: 15px; }
  .stat-grid { grid-template-columns: repeat(2, 1fr); gap: .7rem; }
  .stat { padding: 1.3rem .7rem; }
  .ig-grid { grid-template-columns: repeat(2, 1fr); }
  .song-card-head { flex-direction: column; align-items: flex-start; }
  .btn, .btn-outline { font-size: 1rem; padding: 1.15rem 2.6rem; }
  .timeline { padding-left: 1.7rem; }
  .tl-item { grid-template-columns: 50px 1fr; gap: .7rem; }
  .era-badge { margin-left: -1.7rem; }
}

/* モーション抑制 */
@media (prefers-reduced-motion: reduce) {
  html { scroll-behavior: auto; }
  .reveal { opacity: 1; transform: none; transition: none; }
  .mv-slide { transition: opacity .8s ease; transform: none !important; }
  .btn:hover::after, .btn-outline:hover::after { animation: none; }
}