/* ==========================================================================
   Minecraft World - スタイルシート (style.css)
   ========================================================================== */

/* 1. デザインシステム & 変数定義 */
:root {
  /* カラー定義 */
  --bg-dark: #070709;
  --bg-darker: #040405;
  --bg-card: rgba(20, 20, 25, 0.65);
  --bg-nav: rgba(7, 7, 9, 0.75);
  --border-color: rgba(255, 255, 255, 0.08);
  --border-hover: rgba(255, 255, 255, 0.18);
  
  /* アクセントカラー */
  --accent-green: #3eca4f; /* クリーパー・エメラルド */
  --accent-red: #ff3e3e;   /* レッドストーン */
  --accent-purple: #9d4edd; /* ネザー・ポータル */
  --accent-cyan: #00b4d8;   /* ブルースカイ・ダイヤモンド */
  --accent-gold: #ffb703;   /* エーテル・黄金 */
  
  /* テキストカラー */
  --text-main: #f3f4f6;
  --text-muted: #9ca3af;
  --text-dark: #1f2937;
  
  /* グロー効果（発光） */
  --glow-green: 0 0 20px rgba(62, 202, 79, 0.35);
  --glow-red: 0 0 20px rgba(255, 62, 62, 0.45);
  --glow-purple: 0 0 20px rgba(157, 78, 221, 0.4);
  --glow-cyan: 0 0 20px rgba(0, 180, 216, 0.4);
  --glow-gold: 0 0 20px rgba(255, 183, 3, 0.4);
  --glass-shadow: 0 8px 32px 0 rgba(0, 0, 0, 0.37);
  
  /* トランジション */
  --transition-fast: 0.2s cubic-bezier(0.4, 0, 0.2, 1);
  --transition-normal: 0.4s cubic-bezier(0.4, 0, 0.2, 1);
  --transition-slow: 0.6s cubic-bezier(0.4, 0, 0.2, 1);
}

/* 2. リセット & ベーススタイル */
* {
  margin: 0;
  padding: 0;
  box-sizing: border-box;
}

html {
  scroll-behavior: smooth;
  font-size: 16px;
}

body {
  font-family: 'Noto Sans JP', 'Outfit', sans-serif;
  background-color: var(--bg-dark);
  color: var(--text-main);
  line-height: 1.6;
  overflow-x: hidden;
}

a {
  color: inherit;
  text-decoration: none;
}

li {
  list-style: none;
}

img {
  max-width: 100%;
  height: auto;
  display: block;
}

/* スクロールバーのカスタマイズ */
::-webkit-scrollbar {
  width: 10px;
}
::-webkit-scrollbar-track {
  background: var(--bg-dark);
}
::-webkit-scrollbar-thumb {
  background: rgba(255, 255, 255, 0.15);
  border-radius: 5px;
}
::-webkit-scrollbar-thumb:hover {
  background: rgba(255, 255, 255, 0.3);
}

/* 共通コンポーネント */
.container {
  width: 100%;
  max-width: 1200px;
  margin: 0 auto;
  padding: 0 2rem;
}

.section-padding {
  padding: 8rem 0;
}

/* セクションヘッダー */
.section-header {
  text-align: center;
  margin-bottom: 5rem;
}

.section-header .subtitle {
  font-family: 'Outfit', sans-serif;
  font-size: 0.9rem;
  letter-spacing: 0.3em;
  color: var(--accent-green);
  text-transform: uppercase;
  font-weight: 600;
  display: block;
  margin-bottom: 0.5rem;
}

.section-header .section-title {
  font-size: 2.5rem;
  font-weight: 800;
  letter-spacing: -0.02em;
}

.section-header .header-line {
  width: 60px;
  height: 4px;
  background: linear-gradient(90deg, var(--accent-green), var(--accent-cyan));
  margin: 1.5rem auto 0;
  border-radius: 2px;
}

/* ボタン共通 */
.btn {
  display: inline-flex;
  align-items: center;
  gap: 0.75rem;
  padding: 0.9rem 2rem;
  border-radius: 8px;
  font-weight: 600;
  cursor: pointer;
  transition: var(--transition-fast);
  border: 1px solid transparent;
}

.btn-primary {
  background: linear-gradient(135deg, var(--accent-green), #2db03d);
  color: var(--bg-dark);
}
.btn-primary:hover {
  transform: translateY(-2px);
  box-shadow: var(--glow-green);
}

.btn-secondary {
  background: rgba(255, 255, 255, 0.05);
  color: var(--text-main);
  border-color: var(--border-color);
  backdrop-filter: blur(8px);
}
.btn-secondary:hover {
  background: rgba(255, 255, 255, 0.1);
  border-color: var(--border-hover);
  transform: translateY(-2px);
}

/* 3. ヘッダー / ナビゲーションバー */
#main-header {
  position: fixed;
  top: 0;
  left: 0;
  width: 100%;
  z-index: 1000;
  background: var(--bg-nav);
  backdrop-filter: blur(16px);
  -webkit-backdrop-filter: blur(16px);
  border-bottom: 1px solid var(--border-color);
  transition: var(--transition-normal);
}

.nav-container {
  display: flex;
  justify-content: space-between;
  align-items: center;
  max-width: 1200px;
  margin: 0 auto;
  padding: 1.25rem 2rem;
}

.logo {
  font-family: 'Press Start 2P', cursive;
  font-size: 1.1rem;
  display: flex;
  gap: 0.25rem;
}
.logo-accent {
  color: var(--accent-green);
  text-shadow: 0 0 10px rgba(62, 202, 79, 0.3);
}
.logo-sub {
  color: var(--text-main);
}

.nav-links {
  display: flex;
  gap: 2.5rem;
}

.nav-link {
  font-size: 0.95rem;
  font-weight: 500;
  color: var(--text-muted);
  position: relative;
  transition: var(--transition-fast);
}
.nav-link::after {
  content: '';
  position: absolute;
  bottom: -6px;
  left: 0;
  width: 0;
  height: 2px;
  background: var(--accent-green);
  transition: var(--transition-fast);
}
.nav-link:hover {
  color: var(--text-main);
}
.nav-link:hover::after {
  width: 100%;
}

.mobile-menu-toggle {
  display: none;
  background: none;
  border: none;
  color: var(--text-main);
  font-size: 1.5rem;
  cursor: pointer;
}

/* 4. ヒーローセクション */
.hero-section {
  height: 100vh;
  display: flex;
  align-items: center;
  justify-content: flex-start;
  background-size: cover;
  background-position: center;
  background-attachment: fixed;
  position: relative;
  padding-left: 10%;
  overflow: hidden;
}

.hero-content {
  max-width: 650px;
  z-index: 2;
}

.hero-title {
  font-size: 3.8rem;
  font-weight: 900;
  line-height: 1.15;
  margin-bottom: 1.5rem;
  font-family: 'Noto Sans JP', sans-serif;
  letter-spacing: -0.02em;
}

.hero-title .highlight {
  background: linear-gradient(135deg, var(--accent-green), var(--accent-cyan));
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  text-shadow: 0 0 40px rgba(62, 202, 79, 0.1);
}

.hero-subtitle {
  font-size: 1.15rem;
  color: var(--text-muted);
  margin-bottom: 2.5rem;
  line-height: 1.8;
}

.hero-buttons {
  display: flex;
  gap: 1.5rem;
}

/* スクロールインジケーター */
.scroll-indicator {
  position: absolute;
  bottom: 2.5rem;
  left: 50%;
  transform: translateX(-50%);
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 0.5rem;
  color: var(--text-muted);
  font-family: 'Outfit', sans-serif;
  font-size: 0.75rem;
  letter-spacing: 0.25em;
  z-index: 2;
}

.mouse-wheel {
  width: 20px;
  height: 35px;
  border: 2px solid var(--text-muted);
  border-radius: 10px;
  position: relative;
}
.mouse-wheel::before {
  content: '';
  position: absolute;
  top: 6px;
  left: 50%;
  transform: translateX(-50%);
  width: 4px;
  height: 8px;
  background-color: var(--accent-green);
  border-radius: 2px;
  animation: scroll-wheel 1.6s infinite;
}

@keyframes scroll-wheel {
  0% {
    top: 6px;
    opacity: 1;
  }
  100% {
    top: 18px;
    opacity: 0;
  }
}

/* 5. ゲーム紹介 (About) セクション */
.about-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(320px, 1fr));
  gap: 2.5rem;
}

.about-card {
  background: var(--bg-card);
  backdrop-filter: blur(12px);
  -webkit-backdrop-filter: blur(12px);
  border: 1px solid var(--border-color);
  padding: 3rem 2.5rem;
  border-radius: 16px;
  box-shadow: var(--glass-shadow);
  transition: var(--transition-normal);
  position: relative;
  overflow: hidden;
}

.about-card::before {
  content: '';
  position: absolute;
  top: 0;
  left: 0;
  width: 100%;
  height: 3px;
  background: linear-gradient(90deg, var(--accent-green), transparent);
  opacity: 0;
  transition: var(--transition-fast);
}

.about-card:hover {
  transform: translateY(-8px);
  border-color: var(--border-hover);
  box-shadow: 0 12px 40px 0 rgba(0, 0, 0, 0.5);
}

.about-card:hover::before {
  opacity: 1;
}

.card-icon {
  width: 60px;
  height: 60px;
  background: rgba(62, 202, 79, 0.1);
  border-radius: 12px;
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 1.75rem;
  color: var(--accent-green);
  margin-bottom: 2rem;
  transition: var(--transition-normal);
}

.about-card:hover .card-icon {
  background: var(--accent-green);
  color: var(--bg-dark);
  box-shadow: var(--glow-green);
}

.about-card h3 {
  font-size: 1.5rem;
  font-weight: 700;
  margin-bottom: 1.25rem;
}

.about-card p {
  color: var(--text-muted);
  font-size: 0.95rem;
  line-height: 1.7;
}

/* 6. 歴史・タイムラインセクション */
.timeline-container {
  display: flex;
  flex-direction: column;
  gap: 3.5rem;
}

.timeline-nav {
  display: flex;
  justify-content: space-between;
  background: rgba(255, 255, 255, 0.03);
  padding: 0.5rem;
  border-radius: 50px;
  border: 1px solid var(--border-color);
  max-width: 800px;
  width: 100%;
  margin: 0 auto;
  overflow-x: auto;
  scrollbar-width: none; /* Firefox */
}
.timeline-nav::-webkit-scrollbar {
  display: none; /* Safari, Chrome */
}

.time-btn {
  flex: 1;
  min-width: 80px;
  padding: 0.8rem 1.5rem;
  background: none;
  border: none;
  border-radius: 50px;
  color: var(--text-muted);
  font-family: 'Outfit', sans-serif;
  font-weight: 600;
  font-size: 1rem;
  cursor: pointer;
  transition: var(--transition-fast);
  white-space: nowrap;
}

.time-btn.active, .time-btn:hover {
  background: var(--text-main);
  color: var(--bg-dark);
}

.timeline-content-wrapper {
  max-width: 850px;
  width: 100%;
  margin: 0 auto;
  position: relative;
  min-height: 350px;
}

.timeline-content {
  position: absolute;
  top: 0;
  left: 0;
  width: 100%;
  opacity: 0;
  visibility: hidden;
  transform: translateY(20px);
  transition: opacity var(--transition-normal), transform var(--transition-normal), visibility var(--transition-normal);
  background: var(--bg-card);
  border: 1px solid var(--border-color);
  border-radius: 20px;
  padding: 3.5rem;
  backdrop-filter: blur(12px);
  box-shadow: var(--glass-shadow);
}

.timeline-content.active {
  position: relative;
  opacity: 1;
  visibility: visible;
  transform: translateY(0);
}

.timeline-text {
  display: flex;
  flex-direction: column;
  gap: 1rem;
}

.ver-date {
  font-family: 'Outfit', sans-serif;
  font-size: 0.85rem;
  color: var(--accent-cyan);
  font-weight: 600;
  letter-spacing: 0.1em;
}

.timeline-text h3 {
  font-size: 2.2rem;
  font-weight: 800;
  letter-spacing: -0.01em;
}

.ver-codename {
  font-size: 1.1rem;
  font-weight: 600;
  color: var(--text-main);
  border-left: 3px solid var(--accent-cyan);
  padding-left: 0.75rem;
  margin: 0.25rem 0 0.75rem;
}

.ver-desc {
  color: var(--text-muted);
  font-size: 1.05rem;
  line-height: 1.75;
}

.ver-features {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(240px, 1fr));
  gap: 1rem;
  margin-top: 1.5rem;
  border-top: 1px solid rgba(255, 255, 255, 0.08);
  padding-top: 1.5rem;
}

.ver-features li {
  font-size: 0.95rem;
  display: flex;
  align-items: center;
  gap: 0.75rem;
  color: var(--text-main);
}

.ver-features li i {
  color: var(--accent-cyan);
}

/* 7. レッドストーン回路セクション */
.redstone-container {
  display: grid;
  grid-template-columns: 1fr 1.2fr;
  gap: 3.5rem;
  align-items: stretch;
}

.redstone-info {
  display: flex;
  flex-direction: column;
  justify-content: center;
  background: var(--bg-card);
  border: 1px solid var(--border-color);
  padding: 3rem;
  border-radius: 20px;
  backdrop-filter: blur(12px);
  box-shadow: var(--glass-shadow);
}

.redstone-info h3 {
  font-size: 1.8rem;
  font-weight: 800;
  margin-bottom: 1.25rem;
  border-bottom: 1px solid rgba(255, 255, 255, 0.05);
  padding-bottom: 1rem;
}

.redstone-info p {
  color: var(--text-muted);
  font-size: 1rem;
  line-height: 1.75;
  margin-bottom: 2.5rem;
}

.redstone-tabs {
  display: flex;
  flex-direction: column;
  gap: 1rem;
}

.tab-btn {
  width: 100%;
  text-align: left;
  padding: 1.1rem 1.5rem;
  background: rgba(255, 255, 255, 0.02);
  border: 1px solid var(--border-color);
  border-radius: 10px;
  color: var(--text-muted);
  font-weight: 600;
  font-size: 1rem;
  cursor: pointer;
  transition: var(--transition-fast);
  position: relative;
  display: flex;
  justify-content: space-between;
  align-items: center;
}

.tab-btn::after {
  content: '➜';
  font-size: 0.8rem;
  opacity: 0;
  transform: translateX(-10px);
  transition: var(--transition-fast);
}

.tab-btn:hover {
  background: rgba(255, 255, 255, 0.05);
  border-color: var(--border-hover);
  color: var(--text-main);
}

.tab-btn.active {
  background: rgba(255, 62, 62, 0.08);
  border-color: rgba(255, 62, 62, 0.3);
  color: var(--accent-red);
  box-shadow: inset 0 0 10px rgba(255, 62, 62, 0.05);
}

.tab-btn.active::after {
  opacity: 1;
  transform: translateX(0);
}

/* ディスプレイパネル */
.redstone-display-panel {
  background: var(--bg-card);
  border: 1px solid var(--border-color);
  border-radius: 20px;
  padding: 3rem;
  backdrop-filter: blur(12px);
  box-shadow: var(--glass-shadow);
  display: flex;
  align-items: center;
}

.tab-content {
  display: none;
  width: 100%;
}

.tab-content.active {
  display: block;
  animation: fade-in 0.5s ease-out;
}

@keyframes fade-in {
  from { opacity: 0; transform: translateY(10px); }
  to { opacity: 1; transform: translateY(0); }
}

.display-grid {
  display: grid;
  grid-template-columns: 1.1fr 0.9fr;
  gap: 2rem;
  align-items: center;
}

.circuit-explain h4 {
  font-size: 1.4rem;
  font-weight: 700;
  color: var(--text-main);
  margin-bottom: 1rem;
}

.circuit-explain p {
  color: var(--text-muted);
  font-size: 0.95rem;
  line-height: 1.7;
  margin-bottom: 1.5rem;
}

.parts-list {
  display: flex;
  flex-direction: column;
  gap: 0.75rem;
}

.parts-list li {
  font-size: 0.9rem;
  color: var(--text-muted);
  position: relative;
  padding-left: 1.25rem;
}

.parts-list li::before {
  content: '■';
  position: absolute;
  left: 0;
  top: 1px;
  color: var(--accent-red);
  font-size: 0.7rem;
}

.parts-list li strong {
  color: var(--text-main);
}

.circuit-control {
  margin-top: 1.5rem;
}

.btn-circuit-action {
  padding: 0.8rem 1.5rem;
  background: var(--accent-red);
  color: var(--text-main);
  border: none;
  border-radius: 8px;
  font-weight: 600;
  cursor: pointer;
  transition: var(--transition-fast);
}

.btn-circuit-action:hover {
  transform: translateY(-2px);
  box-shadow: var(--glow-red);
}

/* ビジュアルエリア */
.circuit-visual {
  height: 250px;
  background: var(--bg-darker);
  border: 1px solid rgba(255, 255, 255, 0.05);
  border-radius: 12px;
  display: flex;
  align-items: center;
  justify-content: center;
  position: relative;
  overflow: hidden;
}

/* 基本パーツのピクセルアート風レイアウト */
.pixel-art-grid {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: 1rem;
  width: 90%;
}

.pixel-block {
  background: rgba(255, 255, 255, 0.02);
  border: 1px solid var(--border-color);
  border-radius: 8px;
  height: 90px;
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 0.8rem;
  font-weight: 600;
  color: var(--text-muted);
  position: relative;
  transition: var(--transition-fast);
}

.pixel-block::before {
  content: '';
  position: absolute;
  width: 8px;
  height: 8px;
  border-radius: 50%;
  background: #333;
  top: 12px;
}

.pixel-block.lit {
  color: var(--accent-red);
  border-color: rgba(255, 62, 62, 0.3);
  box-shadow: inset 0 0 15px rgba(255, 62, 62, 0.1);
}

.pixel-block.lit::before {
  background: var(--accent-red);
  box-shadow: var(--glow-red);
}

/* アニメーション用領域 */
.circuit-animation-area {
  position: relative;
  width: 100%;
  height: 100%;
}

/* クロック回路アニメーション */
#clock-anim .anim-wire {
  position: absolute;
  background: #333;
  transition: background 0.15s ease;
}
#clock-anim .anim-wire.active {
  background: var(--accent-red);
  box-shadow: var(--glow-red);
}

#clock-anim .wire-top {
  top: 50px;
  left: 40px;
  width: 140px;
  height: 6px;
}
#clock-anim .wire-bottom {
  bottom: 50px;
  left: 40px;
  width: 140px;
  height: 6px;
}

#clock-anim .anim-repeater {
  position: absolute;
  width: 70px;
  height: 34px;
  background: #252528;
  border: 1px solid var(--border-color);
  border-radius: 4px;
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 0.8rem;
  color: var(--text-muted);
  transition: border-color 0.15s;
}
#clock-anim .anim-repeater.active {
  border-color: var(--accent-red);
  color: var(--accent-red);
  text-shadow: var(--glow-red);
}

#clock-anim .rep-right {
  top: 36px;
  left: 75px;
}
#clock-anim .rep-left {
  bottom: 36px;
  left: 75px;
}

#clock-anim .anim-torch-block {
  position: absolute;
  width: 24px;
  height: 24px;
  background: #3a3a40;
  border: 1px solid var(--border-color);
  left: 20px;
  top: 50%;
  transform: translateY(-50%);
}
#clock-anim .torch-fire {
  width: 8px;
  height: 8px;
  background: #333;
  margin: 7px auto;
  border-radius: 50%;
  transition: background 0.15s;
}
#clock-anim .torch-fire.active {
  background: var(--accent-red);
  box-shadow: var(--glow-red);
}

/* サトウキビ収穫機アニメーション */
#harvester-anim .sugarcane-stalk {
  position: absolute;
  left: 50px;
  bottom: 30px;
  display: flex;
  flex-direction: column-reverse;
}
#harvester-anim .cane {
  width: 24px;
  height: 40px;
  background: #55a630;
  border: 1px solid #386f24;
  margin-top: 1px;
  transition: transform 0.3s cubic-bezier(0.18, 0.89, 0.32, 1.28), opacity 0.3s;
}
#harvester-anim .cane-2 {
  opacity: 0;
  transform: scaleY(0);
  transform-origin: bottom;
}
#harvester-anim .cane-3 {
  opacity: 0;
  transform: scaleY(0);
  transform-origin: bottom;
}

#harvester-anim .block-piston {
  position: absolute;
  left: 100px;
  bottom: 72px;
  width: 50px;
  height: 40px;
  background: #6c584c;
  color: white;
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 0.7rem;
  font-weight: bold;
  border-radius: 4px;
  transition: transform 0.1s;
}
#harvester-anim .block-piston.push {
  transform: translateX(-26px);
  background: #7f5539;
}

#harvester-anim .block-observer {
  position: absolute;
  left: 100px;
  bottom: 113px;
  width: 50px;
  height: 40px;
  background: #4a4e69;
  color: white;
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 0.65rem;
  border-radius: 4px;
  transition: box-shadow 0.2s;
}
#harvester-anim .block-observer.detect {
  box-shadow: 0 0 15px var(--accent-red);
}

#harvester-anim .wire-connection {
  position: absolute;
  left: 150px;
  bottom: 72px;
  width: 6px;
  height: 81px;
  background: #333;
  transition: background 0.15s;
}
#harvester-anim .wire-connection.active {
  background: var(--accent-red);
  box-shadow: var(--glow-red);
}

/* 隠しドアアニメーション */
#door-anim .door-leaf {
  position: absolute;
  width: 35px;
  height: 80px;
  background: #495057;
  border: 1px solid #343a40;
  color: #adb5bd;
  display: flex;
  align-items: center;
  justify-content: center;
  font-weight: bold;
  transition: transform 0.4s ease-in-out;
  z-index: 2;
}
#door-anim .leaf-left {
  left: 70px;
  top: 50%;
  transform: translateY(-50%);
}
#door-anim .leaf-right {
  right: 70px;
  top: 50%;
  transform: translateY(-50%);
}

#door-anim.open .leaf-left {
  transform: translateY(-50%) translate(-20px, -20px);
}
#door-anim.open .leaf-right {
  transform: translateY(-50%) translate(20px, -20px);
}

#door-anim .piston-arm {
  position: absolute;
  width: 20px;
  height: 40px;
  background: #343a40;
  display: flex;
  align-items: center;
  justify-content: center;
  top: 50%;
  transform: translateY(-50%);
  z-index: 1;
  transition: width 0.4s;
}
#door-anim .arm-left {
  left: 50px;
  width: 20px;
}
#door-anim .arm-right {
  right: 50px;
  width: 20px;
}
#door-anim.open .arm-left {
  width: 0px;
}
#door-anim.open .arm-right {
  width: 0px;
}

#door-anim .door-status-text {
  position: absolute;
  bottom: 20px;
  left: 50%;
  transform: translateX(-50%);
  font-size: 0.9rem;
  font-weight: bold;
  color: var(--text-muted);
}

/* 8. BGM環境音プレイヤーセクション */
.player-container {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 4rem;
  background: var(--bg-card);
  border: 1px solid var(--border-color);
  padding: 4rem;
  border-radius: 24px;
  backdrop-filter: blur(16px);
  -webkit-backdrop-filter: blur(16px);
  box-shadow: var(--glass-shadow);
  max-width: 950px;
  margin: 0 auto;
}

/* ビジュアライザー */
.player-visualizer-box {
  background: var(--bg-darker);
  border: 1px solid rgba(255, 255, 255, 0.05);
  border-radius: 16px;
  height: 350px;
  position: relative;
  overflow: hidden;
}

#visualizer-canvas {
  width: 100%;
  height: 100%;
  display: block;
}

.visualizer-overlay {
  position: absolute;
  top: 0;
  left: 0;
  width: 100%;
  height: 100%;
  display: flex;
  flex-direction: column;
  justify-content: center;
  align-items: center;
  gap: 2rem;
  background: linear-gradient(to bottom, transparent, rgba(4, 4, 5, 0.6));
  pointer-events: none;
}

.disk-spinner {
  font-size: 5.5rem;
  color: rgba(255, 255, 255, 0.08);
  transition: color 0.5s, transform 0.5s;
  animation: disk-rotation 8s linear infinite;
  animation-play-state: paused;
}
.disk-spinner.playing {
  color: var(--accent-cyan);
  text-shadow: var(--glow-cyan);
  animation-play-state: running;
}

@keyframes disk-rotation {
  from { transform: rotate(0deg); }
  to { transform: rotate(360deg); }
}

.track-info {
  text-align: center;
  color: white;
}
.track-info h3 {
  font-size: 1.3rem;
  font-weight: 700;
  margin-bottom: 0.25rem;
}
.track-info p {
  font-size: 0.85rem;
  color: var(--text-muted);
}

/* プレイヤーコントロール */
.player-controls-box {
  display: flex;
  flex-direction: column;
  justify-content: space-between;
}

.biome-selector {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: 1rem;
}

.biome-btn {
  background: rgba(255, 255, 255, 0.02);
  border: 1px solid var(--border-color);
  padding: 1rem;
  border-radius: 12px;
  color: var(--text-muted);
  font-weight: 600;
  font-size: 0.95rem;
  cursor: pointer;
  transition: var(--transition-fast);
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 0.75rem;
}
.biome-btn:hover {
  background: rgba(255, 255, 255, 0.05);
  border-color: var(--border-hover);
  color: var(--text-main);
}
.biome-btn.active {
  background: rgba(0, 180, 216, 0.1);
  border-color: rgba(0, 180, 216, 0.4);
  color: var(--accent-cyan);
  box-shadow: inset 0 0 15px rgba(0, 180, 216, 0.05);
}

/* 進捗バー */
.player-progress-bar {
  display: flex;
  align-items: center;
  gap: 1rem;
  margin: 2rem 0;
}
.player-progress-bar span {
  font-family: 'Outfit', sans-serif;
  font-size: 0.85rem;
  color: var(--text-muted);
  min-width: 35px;
}
.progress-track {
  flex: 1;
  height: 6px;
  background: var(--bg-darker);
  border-radius: 3px;
  cursor: pointer;
  position: relative;
}
.progress-fill {
  width: 0%;
  height: 100%;
  background: var(--accent-cyan);
  border-radius: 3px;
  position: relative;
  transition: width 0.1s linear;
}
.progress-fill::after {
  content: '';
  position: absolute;
  right: -5px;
  top: 50%;
  transform: translateY(-50%);
  width: 10px;
  height: 10px;
  background: var(--text-main);
  border-radius: 50%;
  box-shadow: 0 0 8px var(--accent-cyan);
}

/* 制御ボタン */
.player-buttons {
  display: flex;
  justify-content: center;
  align-items: center;
  gap: 2rem;
  margin-bottom: 2rem;
}
.ctrl-btn {
  background: none;
  border: none;
  color: var(--text-muted);
  font-size: 1.25rem;
  cursor: pointer;
  transition: var(--transition-fast);
}
.ctrl-btn:hover {
  color: var(--text-main);
}
.play-pause-btn {
  width: 60px;
  height: 60px;
  border-radius: 50%;
  background: var(--text-main);
  color: var(--bg-dark);
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 1.5rem;
  box-shadow: 0 4px 15px rgba(0, 0, 0, 0.2);
}
.play-pause-btn:hover {
  transform: scale(1.05);
  box-shadow: var(--glow-cyan);
  color: var(--bg-dark);
}

/* 楽曲選択メニュー */
.track-selector-wrapper {
  margin: 1.5rem 0 1rem;
  display: flex;
  flex-direction: column;
  gap: 0.5rem;
}

.track-selector-wrapper label {
  font-size: 0.85rem;
  font-weight: 600;
  color: var(--text-muted);
  display: flex;
  align-items: center;
  gap: 0.5rem;
}

.track-selector-wrapper label i {
  color: var(--accent-cyan);
}

#bgm-track-select {
  width: 100%;
  padding: 0.85rem 1.25rem;
  background: rgba(255, 255, 255, 0.03);
  border: 1px solid var(--border-color);
  border-radius: 10px;
  color: var(--text-main);
  font-weight: 500;
  font-size: 0.95rem;
  outline: none;
  cursor: pointer;
  transition: var(--transition-fast);
  backdrop-filter: blur(8px);
  appearance: none;
  -webkit-appearance: none;
  background-image: url("data:image/svg+xml;charset=UTF-8,%3Csvg xmlns='http://www.w3.org/2000/svg' width='24' height='24' viewBox='0 0 24 24' fill='none' stroke='%239ca3af' stroke-width='2' stroke-linecap='round' stroke-linejoin='round'%3E%3Cpolyline points='6 9 12 15 18 9'%3E%3C/polyline%3E%3C/svg%3E");
  background-repeat: no-repeat;
  background-position: right 1rem center;
  background-size: 1em;
  padding-right: 2.5rem;
}

#bgm-track-select:hover {
  background-color: rgba(255, 255, 255, 0.06);
  border-color: var(--border-hover);
}

#bgm-track-select:focus {
  border-color: var(--accent-cyan);
  box-shadow: 0 0 0 2px rgba(0, 180, 216, 0.2);
}

#bgm-track-select option {
  background-color: #0c0c10;
  color: var(--text-main);
}

/* 音量調整 */
.volume-control {
  display: flex;
  align-items: center;
  gap: 1rem;
  justify-content: center;
}
.volume-control i {
  color: var(--text-muted);
  font-size: 0.95rem;
  width: 15px;
}
#volume-slider {
  -webkit-appearance: none;
  width: 130px;
  height: 4px;
  background: var(--bg-darker);
  border-radius: 2px;
  outline: none;
}
#volume-slider::-webkit-slider-thumb {
  -webkit-appearance: none;
  width: 12px;
  height: 12px;
  border-radius: 50%;
  background: var(--text-main);
  cursor: pointer;
  transition: transform 0.1s;
}
#volume-slider::-webkit-slider-thumb:hover {
  transform: scale(1.2);
}

.player-disclaimer {
  font-size: 0.75rem;
  color: var(--text-muted);
  text-align: center;
  margin-top: 1.5rem;
  line-height: 1.5;
}

/* 9. MOD紹介 (Featured Mods) セクション */
.mods-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(340px, 1fr));
  gap: 3rem;
}

.mod-card {
  height: 480px;
  border-radius: 24px;
  background-image: var(--card-bg);
  background-size: cover;
  background-position: center;
  position: relative;
  overflow: hidden;
  border: 1px solid var(--border-color);
  box-shadow: var(--glass-shadow);
  display: flex;
  align-items: flex-end;
  transition: var(--transition-slow);
}

.mod-card-overlay {
  position: absolute;
  top: 0;
  left: 0;
  width: 100%;
  height: 100%;
  background: linear-gradient(to bottom, rgba(4, 4, 5, 0.2) 20%, rgba(4, 4, 5, 0.95) 90%);
  z-index: 1;
  transition: var(--transition-normal);
}

.mod-card-content {
  position: relative;
  z-index: 2;
  padding: 3rem 2.5rem;
  width: 100%;
  transition: transform var(--transition-slow);
}

.mod-category {
  font-family: 'Outfit', sans-serif;
  font-size: 0.75rem;
  font-weight: 700;
  letter-spacing: 0.2em;
  color: var(--accent-cyan);
  text-transform: uppercase;
  display: block;
  margin-bottom: 0.75rem;
  transition: color var(--transition-normal);
}

.mod-card h3 {
  font-size: 2rem;
  font-weight: 800;
  line-height: 1.2;
  margin-bottom: 1.25rem;
}

.mod-card h3 .mod-en {
  font-family: 'Outfit', sans-serif;
  font-size: 0.95rem;
  font-weight: 500;
  color: var(--text-muted);
  display: block;
  margin-top: 0.25rem;
}

.mod-summary {
  color: var(--text-muted);
  font-size: 0.95rem;
  line-height: 1.6;
  transition: opacity var(--transition-normal);
}

/* カード詳細情報（通常時は隠して、ホバー時に浮かび上がらせる） */
.mod-details {
  max-height: 0;
  opacity: 0;
  overflow: hidden;
  transition: max-height var(--transition-slow), opacity var(--transition-slow);
  margin-top: 0rem;
  display: flex;
  flex-direction: column;
  gap: 1.25rem;
  border-top: 1px solid rgba(255, 255, 255, 0.08);
  padding-top: 0rem;
}

.detail-item {
  font-size: 0.85rem;
  line-height: 1.6;
}
.detail-item strong {
  display: block;
  color: var(--text-main);
  margin-bottom: 0.25rem;
}
.detail-item strong i {
  margin-right: 0.5rem;
  color: var(--accent-cyan);
}
.detail-item span {
  color: var(--text-muted);
}

/* ホバーエフェクト */
.mod-card:hover {
  transform: translateY(-10px);
  border-color: var(--border-hover);
  box-shadow: 0 20px 50px rgba(0, 0, 0, 0.6);
}

.mod-card:hover .mod-card-overlay {
  background: linear-gradient(to bottom, rgba(4, 4, 5, 0.05) 0%, rgba(4, 4, 5, 0.98) 75%);
}

.mod-card:hover .mod-card-content {
  transform: translateY(0);
}

.mod-card:hover .mod-details {
  max-height: 300px;
  opacity: 1;
  margin-top: 1.5rem;
  padding-top: 1.5rem;
}

/* カードごとのアクセントカラー調整 */
.mod-card.accent-green .mod-category,
.mod-card.accent-green .detail-item strong i,
.mod-card.accent-green .detail-link-indicator {
  color: var(--accent-green);
}
.mod-card.accent-cyan .mod-category,
.mod-card.accent-cyan .detail-item strong i,
.mod-card.accent-cyan .detail-link-indicator {
  color: var(--accent-cyan);
}
.mod-card.accent-purple .mod-category,
.mod-card.accent-purple .detail-item strong i,
.mod-card.accent-purple .detail-link-indicator {
  color: var(--accent-purple);
}
.mod-card.accent-gold .mod-category,
.mod-card.accent-gold .detail-item strong i,
.mod-card.accent-gold .detail-link-indicator {
  color: var(--accent-gold);
}

/* サブセクションヘッダー */
.mods-subsection-header {
  margin-top: 3rem;
  margin-bottom: 2.5rem;
  text-align: left;
  border-left: 4px solid var(--accent-green);
  padding-left: 1.25rem;
}
.mods-subsection-header h3 {
  font-size: 1.6rem;
  font-weight: 700;
  color: var(--text-main);
  display: flex;
  align-items: center;
  gap: 0.75rem;
}
.mods-subsection-header h3 i {
  color: var(--accent-green);
}
.mods-subsection-header p {
  color: var(--text-muted);
  font-size: 0.95rem;
  margin-top: 0.5rem;
}

/* 影MODサブセクション用のヘッダー色調整 */
.mods-subsection-header:nth-of-type(2) {
  border-left-color: var(--accent-cyan);
}
.mods-subsection-header:nth-of-type(2) h3 i {
  color: var(--accent-cyan);
}

/* 詳細リンクの矢印表示 */
.detail-link-indicator {
  display: flex;
  align-items: center;
  justify-content: flex-end;
  gap: 0.5rem;
  font-weight: 600;
  font-size: 0.9rem;
  margin-top: auto;
  padding-top: 0.5rem;
  transition: var(--transition-fast);
}
.detail-link-indicator span {
  border-bottom: 1px dashed transparent;
}
.mod-card:hover .detail-link-indicator span {
  border-bottom-color: currentColor;
}
.mod-card:hover .detail-link-indicator i {
  transform: translateX(4px);
}
.detail-link-indicator i {
  transition: transform var(--transition-fast);
}

/* 影MODダウンロードボタン */
.detail-action-container {
  margin-top: auto;
  padding-top: 0.5rem;
  width: 100%;
}
.btn-download-shader {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 0.5rem;
  width: 100%;
  padding: 0.8rem 1.5rem;
  border-radius: 8px;
  font-weight: 600;
  font-size: 0.9rem;
  cursor: pointer;
  background: rgba(255, 255, 255, 0.05);
  border: 1px solid var(--border-color);
  color: var(--text-main);
  transition: var(--transition-fast);
  backdrop-filter: blur(8px);
}
.mod-card.accent-cyan .btn-download-shader:hover {
  background: var(--accent-cyan);
  color: var(--bg-dark);
  box-shadow: var(--glow-cyan);
  border-color: var(--accent-cyan);
}
.mod-card.accent-purple .btn-download-shader:hover {
  background: var(--accent-purple);
  color: var(--text-main);
  box-shadow: var(--glow-purple);
  border-color: var(--accent-purple);
}
.mod-card.accent-gold .btn-download-shader:hover {
  background: var(--accent-gold);
  color: var(--bg-dark);
  box-shadow: var(--glow-gold);
  border-color: var(--accent-gold);
}

/* 10. フッター */
.main-footer {
  background-color: var(--bg-darker);
  border-top: 1px solid var(--border-color);
  padding: 6rem 0 3rem;
  color: var(--text-muted);
  font-size: 0.9rem;
}

.footer-grid {
  display: grid;
  grid-template-columns: 1.5fr 1fr 1.5fr;
  gap: 5rem;
  margin-bottom: 4rem;
}

.footer-brand h3 {
  font-family: 'Press Start 2P', cursive;
  font-size: 1rem;
  color: var(--accent-green);
  margin-bottom: 1.5rem;
}
.footer-brand p {
  line-height: 1.7;
}

.footer-links h4,
.footer-disclaimer h4 {
  color: var(--text-main);
  font-size: 1.05rem;
  font-weight: 700;
  margin-bottom: 1.5rem;
}

.footer-links ul {
  display: flex;
  flex-direction: column;
  gap: 0.75rem;
}
.footer-links a:hover {
  color: var(--text-main);
}

.footer-disclaimer p {
  line-height: 1.6;
}

.footer-bottom {
  border-top: 1px solid rgba(255, 255, 255, 0.05);
  padding-top: 2rem;
  text-align: center;
  font-size: 0.8rem;
}

/* 11. スクロールアニメーション (Reveal) */
.reveal {
  opacity: 0;
  transform: translateY(30px);
  transition: opacity 0.8s ease-out, transform 0.8s ease-out;
}
.reveal.active {
  opacity: 1;
  transform: translateY(0);
}

/* 12. レスポンシブデザイン */
@media (max-width: 1024px) {
  .hero-title {
    font-size: 3.2rem;
  }
  .redstone-container {
    grid-template-columns: 1fr;
    gap: 2.5rem;
  }
  .player-container {
    grid-template-columns: 1fr;
    gap: 3rem;
    padding: 3rem;
  }
}

@media (max-width: 768px) {
  .section-padding {
    padding: 5rem 0;
  }
  .section-header {
    margin-bottom: 3.5rem;
  }
  .section-header .section-title {
    font-size: 2rem;
  }
  
  /* モバイルナビゲーション */
  .mobile-menu-toggle {
    display: block;
    z-index: 1001;
  }
  .nav-links {
    position: fixed;
    top: 0;
    right: -100%;
    width: 250px;
    height: 100vh;
    background: #0c0c10;
    flex-direction: column;
    padding: 6rem 2rem;
    gap: 2rem;
    box-shadow: -5px 0 30px rgba(0,0,0,0.5);
    transition: var(--transition-normal);
  }
  .nav-links.active {
    right: 0;
  }
  
  /* ヒーロー */
  .hero-section {
    padding-left: 2rem;
    padding-right: 2rem;
  }
  .hero-title {
    font-size: 2.5rem;
  }
  .hero-subtitle {
    font-size: 1rem;
  }
  .hero-buttons {
    flex-direction: column;
    gap: 1rem;
  }
  
  /* タイムライン */
  .timeline-content {
    padding: 2rem;
  }
  .timeline-text h3 {
    font-size: 1.6rem;
  }
  .ver-features {
    grid-template-columns: 1fr;
  }
  
  /* レッドストーン */
  .redstone-display-panel {
    padding: 2rem;
  }
  .display-grid {
    grid-template-columns: 1fr;
    gap: 2.5rem;
  }
  
  /* フッター */
  .footer-grid {
    grid-template-columns: 1fr;
    gap: 3rem;
  }
}