/**
 * AI进化游戏 - 赛博朋克主样式
 * 深色主题配合霓虹色彩的视觉设计
 */

/* === 赛博朋克色彩变量 === */
:root {
  /* 主要色彩 */
  --cyber-black: #0a0a0a;
  --cyber-dark: #1a1a2e;
  --cyber-darker: #16213e;
  --cyber-navy: #0f3460;
  
  /* 霓虹色彩 */
  --neon-cyan: #00ffff;
  --neon-pink: #ff006e;
  --neon-green: #39ff14;
  --neon-purple: #bf00ff;
  --neon-orange: #ff8c00;
  --neon-blue: #0080ff;
  
  /* 渐变色彩 */
  --gradient-cyber: linear-gradient(135deg, var(--neon-cyan), var(--neon-purple));
  --gradient-matrix: linear-gradient(90deg, var(--neon-green), var(--cyber-dark));
  --gradient-electric: linear-gradient(45deg, var(--neon-pink), var(--neon-orange));
  
  /* 文本颜色 */
  --text-primary: #ffffff;
  --text-secondary: #a0a0a0;
  --text-accent: var(--neon-cyan);
  
  /* 界面颜色 */
  --ui-border: var(--neon-cyan);
  --ui-glow: 0 0 20px var(--neon-cyan);
  --ui-shadow: 0 4px 15px rgba(0, 255, 255, 0.3);
}

/* === 基础重置和布局 === */
* {
  margin: 0;
  padding: 0;
  box-sizing: border-box;
}

body {
  background: var(--cyber-black);
  color: var(--text-primary);
  font-family: 'Courier New', 'Monaco', 'Lucida Console', monospace;
  overflow: hidden;
  user-select: none;
  height: 100vh;
}

/* === 游戏容器 === */
#game-container {
  position: relative;
  width: 100vw;
  height: 100vh;
  background: radial-gradient(ellipse at center, var(--cyber-darker) 0%, var(--cyber-black) 100%);
  display: flex;
  justify-content: center;
  align-items: center;
}

/* === Canvas样式 === */
#game-canvas {
  border: 2px solid var(--ui-border);
  border-radius: 0 0 8px 8px; /* 顶部直角，与 info-panel 无缝衔接 */
  box-shadow: var(--ui-glow), inset 0 0 20px rgba(0, 255, 255, 0.1);
  background: linear-gradient(135deg, rgba(26, 26, 46, 0.9) 0%, rgba(15, 52, 96, 0.8) 100%);
  cursor: crosshair;
  transition: box-shadow 0.3s ease;
  /* 移动端自适应：不超出屏幕 */
  max-width: 100vw;
  max-height: 100vh;
  touch-action: none; /* 防止移动端滑动干扰 */
}

#game-canvas:hover {
  box-shadow: 
    0 0 30px var(--neon-cyan),
    0 0 60px rgba(0, 255, 255, 0.3),
    inset 0 0 20px rgba(0, 255, 255, 0.1);
}

/* === UI覆盖层 === */
#ui-overlay {
  position: absolute;
  top: 0;
  left: 0;
  right: 0;
  bottom: 0;
  pointer-events: none;
  z-index: 10;
}

/* === 信息面板 === */
#info-panel {
  position: absolute;
  top: 0;
  left: 0;
  right: 0;
  height: 48px;
  background: linear-gradient(90deg, rgba(0,0,0,0.55), rgba(0,0,0,0.45));
  border-bottom: 1px solid var(--ui-border);
  border-radius: 0; /* 与 canvas 顶部融合，无圆角 */
  padding: 0 16px 0 16px;
  display: flex;
  align-items: center;
  justify-content: space-between;
  backdrop-filter: blur(12px);
  pointer-events: all;
  z-index: 15;
  /* 右侧为倒计时留位 */
  padding-right: 100px;
}

#current-stage {
  font-size: 13px;
  font-weight: bold;
  color: var(--text-accent);
  text-shadow: 0 0 10px var(--neon-cyan);
  white-space: nowrap;
  flex-shrink: 0;
}

/* 得分显示 */
#score-display {
  display: flex;
  flex-direction: column;
  align-items: center;
  flex-shrink: 0;
  min-width: 52px;
}

#score-label {
  font-size: 9px;
  letter-spacing: 2px;
  color: rgba(0,255,255,0.5);
  line-height: 1;
}

#score-value {
  font-size: 18px;
  font-weight: bold;
  font-family: 'Courier New', monospace;
  color: var(--neon-cyan);
  text-shadow: 0 0 8px var(--neon-cyan);
  line-height: 1.2;
  transition: transform 0.15s ease, color 0.15s ease;
}

/* 得分跳动动画 */
#score-value.pop {
  transform: scale(1.3);
  color: #ffffff;
}

#progress-bar {
  flex: 1;
  height: 8px;
  background: rgba(255, 255, 255, 0.1);
  border-radius: 4px;
  margin: 0 20px;
  overflow: hidden;
  position: relative;
}

#progress-fill {
  height: 100%;
  background: var(--gradient-cyber);
  border-radius: 4px;
  width: 0%;
  transition: width 0.5s ease;
  box-shadow: 0 0 10px var(--neon-cyan);
}

/* === 消息区域 === */
#message-area {
  position: absolute;
  top: 56px; /* info-panel 高度 48px + 8px 间距 */
  left: 50%;
  transform: translateX(-50%);
  width: 90%;
  max-width: 600px;
  text-align: center;
  pointer-events: none;
}

#evolution-message,
#narrative-message {
  background: linear-gradient(135deg, rgba(0, 255, 255, 0.2), rgba(255, 0, 110, 0.2));
  border: 1px solid var(--neon-pink);
  border-radius: 8px;
  padding: 15px 25px;
  margin: 10px 0;
  font-size: 14px;
  color: var(--text-primary);
  text-shadow: 0 0 5px var(--neon-pink);
  backdrop-filter: blur(15px);
  opacity: 0;
  /* 消息定位：居中悬浮 */
  position: absolute;
  left: 50%;
  top: 90px;
  transform: translateX(-50%) translateY(-20px);
  width: 80%;
  max-width: 500px;
  text-align: center;
  transition: opacity 0.4s ease, transform 0.4s ease;
  z-index: 20;
}

#evolution-message.show,
#narrative-message.show {
  opacity: 1;
  transform: translateX(-50%) translateY(0);
}

/* === 控制面板 === */
#control-panel {
  position: absolute;
  bottom: 30px;
  left: 50%;
  transform: translateX(-50%);
  display: flex;
  gap: 15px;
  pointer-events: all;
}

/* === 赛博朋克按钮 === */
.cyberpunk-btn {
  white-space: nowrap;
  background: transparent;
  border: 2px solid var(--neon-cyan);
  color: var(--text-accent);
  padding: 12px 24px;
  font-family: inherit;
  font-size: 14px;
  font-weight: bold;
  border-radius: 6px;
  cursor: pointer;
  position: relative;
  overflow: hidden;
  text-transform: uppercase;
  letter-spacing: 1px;
  transition: all 0.3s ease;
  box-shadow: inset 0 0 20px rgba(0, 255, 255, 0.1);
}

.cyberpunk-btn::before {
  content: '';
  position: absolute;
  top: 0;
  left: -100%;
  width: 100%;
  height: 100%;
  background: linear-gradient(90deg, transparent, var(--neon-cyan), transparent);
  transition: left 0.5s ease;
  opacity: 0.3;
}

.cyberpunk-btn:hover {
  color: var(--cyber-black);
  background: var(--neon-cyan);
  box-shadow: 
    0 0 20px var(--neon-cyan),
    0 0 40px rgba(0, 255, 255, 0.5);
  text-shadow: none;
}

.cyberpunk-btn:hover::before {
  left: 100%;
}

.cyberpunk-btn:active {
  transform: scale(0.98);
}

/* === 加载屏幕 === */
#loading-screen {
  position: absolute;
  top: 0;
  left: 0;
  width: 100%;
  height: 100%;
  background: var(--cyber-black);
  display: flex;
  justify-content: center;
  align-items: center;
  z-index: 1000;
}

#loading-animation {
  text-align: center;
}

.loading-dots {
  display: flex;
  gap: 8px;
  justify-content: center;
  margin-bottom: 20px;
}

.loading-dots span {
  width: 12px;
  height: 12px;
  border-radius: 50%;
  background: var(--neon-cyan);
  display: inline-block;
  animation: loading-pulse 1.4s infinite ease-in-out;
  box-shadow: 0 0 10px var(--neon-cyan);
}

.loading-dots span:nth-child(1) { animation-delay: -0.32s; }
.loading-dots span:nth-child(2) { animation-delay: -0.16s; }

#loading-animation p {
  color: var(--text-accent);
  font-size: 16px;
  text-shadow: 0 0 10px var(--neon-cyan);
  animation: text-glow 2s ease-in-out infinite alternate;
}

/* === 最终场景覆盖层 === */
#finale-overlay {
  position: absolute;
  top: 0;
  left: 0;
  width: 100%;
  height: 100%;
  background: radial-gradient(circle, rgba(255, 0, 110, 0.9) 0%, var(--cyber-black) 100%);
  display: flex;
  justify-content: center;
  align-items: center;
  z-index: 2000;
  backdrop-filter: blur(20px);
}

#finale-content {
  text-align: center;
  max-width: 80%;
}

#finale-content h1 {
  font-size: 48px;
  color: var(--neon-pink);
  text-shadow: 0 0 20px var(--neon-pink);
  margin-bottom: 30px;
  animation: finale-glow 2s ease-in-out infinite alternate;
}

#finale-text {
  font-size: 18px;
  line-height: 1.6;
  color: var(--text-primary);
  text-shadow: 0 0 5px var(--neon-cyan);
}

/* === 失败遮罩 === */
#gameover-overlay {
  position: absolute;
  inset: 0;
  background: rgba(0, 0, 0, 0.85);
  display: flex;
  align-items: center;
  justify-content: center;
  z-index: 50;
  animation: fadeIn 0.5s ease;
}

#gameover-content {
  text-align: center;
  padding: 40px;
}

#gameover-glitch {
  font-size: 13px;
  letter-spacing: 6px;
  color: #ff003c;
  text-shadow: 0 0 10px #ff003c;
  margin-bottom: 16px;
  animation: glitch-text 0.3s infinite;
}

@keyframes glitch-text {
  0%   { transform: translate(0); opacity: 1; }
  25%  { transform: translate(-2px, 1px); opacity: 0.8; }
  50%  { transform: translate(2px, -1px); opacity: 1; }
  75%  { transform: translate(-1px, 2px); opacity: 0.9; }
  100% { transform: translate(0); opacity: 1; }
}

#gameover-title {
  font-size: 36px;
  color: #ff003c;
  text-shadow: 0 0 20px #ff003c, 0 0 40px #ff003c;
  margin-bottom: 16px;
}

#gameover-desc {
  color: #aaa;
  font-size: 15px;
  line-height: 1.8;
  margin-bottom: 20px;
}

#gameover-stats {
  color: var(--neon-cyan);
  font-size: 13px;
  font-family: monospace;
  line-height: 2;
  border: 1px solid rgba(0,255,255,0.2);
  padding: 12px 20px;
  border-radius: 6px;
  background: rgba(0,255,255,0.05);
}

/* === 倒计时 === */
#countdown-timer {
  position: absolute;
  top: 0;
  right: 0;
  height: 48px; /* 与 info-panel 等高 */
  display: none;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  background: rgba(0,0,0,0.3);
  border-left: 1px solid rgba(0,255,255,0.2);
  padding: 0 16px;
  pointer-events: none;
  z-index: 20;
  min-width: 80px;
}

#countdown-label {
  font-size: 9px;
  letter-spacing: 3px;
  color: rgba(0,255,255,0.5);
  margin-bottom: 1px;
}

#countdown-value {
  font-size: 20px;
  font-weight: bold;
  font-family: 'Courier New', monospace;
  color: var(--neon-cyan);
  text-shadow: 0 0 8px var(--neon-cyan);
  letter-spacing: 2px;
}

/* 最后30秒变红警告 */
#countdown-timer.urgent {
  border-color: rgba(255,0,60,0.6);
  animation: urgentPulse 0.8s ease-in-out infinite;
}
#countdown-timer.urgent #countdown-value {
  color: #ff003c;
  text-shadow: 0 0 12px #ff003c;
}
#countdown-timer.urgent #countdown-label {
  color: rgba(255,0,60,0.6);
}

@keyframes urgentPulse {
  0%,100% { box-shadow: 0 0 0px rgba(255,0,60,0); }
  50%      { box-shadow: 0 0 14px rgba(255,0,60,0.5); }
}

/* 游戏进行中显示倒计时 */
body[data-env] #countdown-timer {
  display: flex;
}

/* === 分享弹窗 === */
#share-overlay {
  position: fixed;
  inset: 0;
  background: rgba(0,0,0,0.75);
  display: flex;
  align-items: center;
  justify-content: center;
  z-index: 9999;
  backdrop-filter: blur(4px);
}

#share-modal {
  background: rgba(10,10,30,0.95);
  border: 1px solid var(--neon-cyan);
  border-radius: 12px;
  padding: 32px 28px;
  width: min(90vw, 380px);
  text-align: center;
  box-shadow: 0 0 30px rgba(0,255,255,0.2), 0 0 60px rgba(0,255,255,0.08);
  animation: fadeIn 0.3s ease;
}

#share-modal-title {
  font-size: 18px;
  color: var(--neon-cyan);
  letter-spacing: 3px;
  margin-bottom: 12px;
  text-shadow: 0 0 10px var(--neon-cyan);
}

#share-modal-desc {
  font-size: 13px;
  color: rgba(255,255,255,0.6);
  line-height: 1.7;
  margin-bottom: 18px;
}

#share-link-box {
  background: rgba(0,255,255,0.05);
  border: 1px solid rgba(0,255,255,0.25);
  border-radius: 6px;
  padding: 10px 14px;
  margin-bottom: 20px;
  word-break: break-all;
}

#share-link-text {
  font-size: 12px;
  color: var(--neon-cyan);
  font-family: monospace;
  opacity: 0.9;
}

#share-actions {
  display: flex;
  gap: 12px;
  justify-content: center;
  flex-wrap: wrap;
}

#share-copy-btn {
  background: rgba(0,255,255,0.12);
  min-width: 120px;
}

#share-copy-btn.copied {
  background: rgba(57,255,20,0.15);
  border-color: var(--neon-green);
  color: var(--neon-green);
}

/* ═══════════════════════════════════════════
   首页视觉设计
═══════════════════════════════════════════ */
#home-screen {
  position: absolute;
  inset: 0;
  display: flex;
  align-items: center;
  justify-content: center;
  pointer-events: none;
  z-index: 5;
}

#home-title-wrap {
  text-align: center;
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 10px;
  /* 偏上一些，给底部按钮让位 */
  margin-top: -60px;
}

/* 顶部英文副标 */
#home-subtitle-top {
  font-size: 11px;
  letter-spacing: 5px;
  color: var(--neon-cyan);
  opacity: 0.7;
  font-family: 'Courier New', monospace;
  animation: fadeInDown 1s ease both;
}

/* ── 主标题：合成大主宰 ── */
#home-title {
  font-size: clamp(36px, 10vw, 72px);
  font-weight: 900;
  letter-spacing: 6px;
  line-height: 1;
  background: linear-gradient(135deg, #ffffff 0%, #00ffff 40%, #bf00ff 80%, #ff006e 100%);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
  filter: drop-shadow(0 0 18px rgba(0,255,255,0.6)) drop-shadow(0 0 40px rgba(191,0,255,0.4));
  animation: titleAppear 1.2s cubic-bezier(0.22,1,0.36,1) both, titleGlow 3s ease-in-out 1.2s infinite;
  position: relative;
}

/* 标题故障闪烁层 */
#home-title::before {
  content: '合成大主宰';
  position: absolute;
  inset: 0;
  background: linear-gradient(135deg, #ff006e, #00ffff);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
  animation: glitchA 4s infinite;
  clip-path: polygon(0 20%, 100% 20%, 100% 35%, 0 35%);
  opacity: 0;
}
#home-title::after {
  content: '合成大主宰';
  position: absolute;
  inset: 0;
  background: linear-gradient(135deg, #bf00ff, #ffffff);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
  animation: glitchB 4s infinite;
  clip-path: polygon(0 60%, 100% 60%, 100% 75%, 0 75%);
  opacity: 0;
}

@keyframes glitchA {
  0%,94%,100% { opacity:0; transform: translate(0); }
  95%          { opacity:0.8; transform: translate(-3px, 1px); }
  97%          { opacity:0.8; transform: translate(3px, -1px); }
}
@keyframes glitchB {
  0%,92%,100% { opacity:0; transform: translate(0); }
  93%          { opacity:0.7; transform: translate(3px, 2px); }
  96%          { opacity:0.7; transform: translate(-2px, -1px); }
}

@keyframes titleAppear {
  from { opacity:0; transform: scale(0.7) translateY(20px); filter: drop-shadow(0 0 0px transparent); }
  to   { opacity:1; transform: scale(1) translateY(0); }
}
@keyframes titleGlow {
  0%,100% { filter: drop-shadow(0 0 18px rgba(0,255,255,0.6)) drop-shadow(0 0 40px rgba(191,0,255,0.4)); }
  50%     { filter: drop-shadow(0 0 28px rgba(0,255,255,0.9)) drop-shadow(0 0 60px rgba(191,0,255,0.7)); }
}

/* 英文副标 */
#home-title-en {
  font-size: 12px;
  letter-spacing: 8px;
  color: rgba(255,255,255,0.35);
  font-family: 'Courier New', monospace;
  animation: fadeInDown 1.4s ease both;
}

/* 描述文字 */
#home-desc {
  font-size: 13px;
  line-height: 1.9;
  color: rgba(255,255,255,0.55);
  letter-spacing: 1px;
  margin-top: 6px;
  animation: fadeInDown 1.6s ease both;
}

/* ── 进化链预览 ── */
#home-evo-chain {
  display: flex;
  align-items: center;
  gap: 8px;
  margin-top: 14px;
  animation: fadeInDown 1.8s ease both;
}

#home-evo-chain span {
  font-size: 22px;
  filter: drop-shadow(0 0 6px rgba(0,255,255,0.5));
  animation: evoFloat 2.5s ease-in-out infinite;
}
#home-evo-chain span:nth-child(1) { animation-delay: 0s; }
#home-evo-chain span:nth-child(3) { animation-delay: 0.3s; }
#home-evo-chain span:nth-child(5) { animation-delay: 0.6s; }
#home-evo-chain span:nth-child(7) { animation-delay: 0.9s; }
#home-evo-chain span:nth-child(9) { animation-delay: 1.2s; }

.chain-arrow {
  font-size: 12px !important;
  color: var(--neon-cyan);
  opacity: 0.5;
  animation: none !important;
  filter: none !important;
}

@keyframes evoFloat {
  0%,100% { transform: translateY(0); }
  50%      { transform: translateY(-5px); }
}

@keyframes fadeInDown {
  from { opacity:0; transform: translateY(-12px); }
  to   { opacity:1; transform: translateY(0); }
}

/* 游戏进行中隐藏首页 */
body[data-env] #home-screen {
  display: none;
}

/* ── 开始按钮升级 ── */
#start-game {
  font-size: 15px;
  padding: 14px 40px;
  letter-spacing: 3px;
  position: relative;
  overflow: hidden;
  white-space: nowrap; /* 禁止文字换行 */
}

/* 扫光动画 */
#start-game::after {
  content: '';
  position: absolute;
  top: 0; left: -100%;
  width: 60%;
  height: 100%;
  background: linear-gradient(90deg, transparent, rgba(255,255,255,0.15), transparent);
  animation: btnScan 2.5s ease-in-out infinite;
}
@keyframes btnScan {
  0%   { left: -100%; }
  60%  { left: 150%; }
  100% { left: 150%; }
}

/* === CSS3 背景环境动画 === */
@keyframes canvas-breathe {
  0%, 100% { opacity: 0.95; }
  50%       { opacity: 1; }
}

/* 环境1：电路板 - 绿色脉冲 */
body[data-env="1"] #game-canvas {
  animation: canvas-breathe 3s ease-in-out infinite;
  border-color: #00ff46;
}
/* 环境2：服务器 - 蓝色扫描呼吸 */
body[data-env="2"] #game-canvas {
  animation: canvas-breathe 2s ease-in-out infinite;
  border-color: #0080ff;
}
/* 环境3：城市 - 粉色霓虹 */
body[data-env="3"] #game-canvas {
  animation: canvas-breathe 1.8s ease-in-out infinite;
  border-color: #ff00ae;
}
/* 环境4：太空 - 金色呼吸 */
body[data-env="4"] #game-canvas {
  animation: canvas-breathe 4s ease-in-out infinite;
  border-color: #ffcc00;
}
/* 环境5：数字宇宙 - 白色快速脉冲 */
body[data-env="5"] #game-canvas {
  animation: canvas-breathe 0.8s ease-in-out infinite;
  border-color: #ffffff;
}

/* 游戏容器外发光跟随环境 */
@keyframes env-glow-1 {
  0%,100% { background: radial-gradient(ellipse at center, #0a1a0a 0%, #0a0a0a 100%); }
  50%      { background: radial-gradient(ellipse at center, #0d200d 0%, #0a0a0a 100%); }
}
@keyframes env-glow-5 {
  0%,100% { background: radial-gradient(ellipse at center, #0a0520 0%, #000008 100%); }
  50%      { background: radial-gradient(ellipse at center, #12083a 0%, #000008 100%); }
}
body[data-env="5"] #game-container {
  animation: env-glow-5 2s ease-in-out infinite;
}

/* === 动画定义 === */
@keyframes loading-pulse {
  0%, 80%, 100% {
    transform: scale(0.8);
    opacity: 0.5;
  }
  40% {
    transform: scale(1);
    opacity: 1;
  }
}

@keyframes text-glow {
  from {
    text-shadow: 0 0 10px var(--neon-cyan);
  }
  to {
    text-shadow: 
      0 0 20px var(--neon-cyan),
      0 0 30px var(--neon-cyan),
      0 0 40px var(--neon-cyan);
  }
}

@keyframes finale-glow {
  from {
    text-shadow: 0 0 20px var(--neon-pink);
  }
  to {
    text-shadow: 
      0 0 30px var(--neon-pink),
      0 0 40px var(--neon-pink),
      0 0 60px var(--neon-pink);
  }
}

/* === 响应式设计 === */
@media (max-width: 768px) {
  #game-canvas {
    border-width: 1px;
  }
  
  #info-panel {
    height: 50px;
    padding: 8px 15px;
    font-size: 14px;
  }
  
  #current-stage {
    font-size: 14px;
  }
  
  .cyberpunk-btn {
    padding: 10px 20px;
    font-size: 12px;
  }
  
  #finale-content h1 {
    font-size: 32px;
  }
  
  #finale-text {
    font-size: 16px;
  }
}

@media (max-width: 480px) {
  #control-panel {
    flex-direction: column;
    align-items: center;
    bottom: 15px;
    gap: 10px;
  }
  
  .cyberpunk-btn {
    width: 180px;
    padding: 10px 16px;
    font-size: 11px;
  }
  
  #info-panel {
    left: 8px;
    right: 8px;
    height: auto;
    min-height: 68px;
    padding: 6px 12px;
    padding-right: 80px; /* 为倒计时留位（第一行右侧） */
    flex-wrap: wrap;
    align-content: flex-start;
    row-gap: 4px;
  }

  /* 第一行：阶段文字占满宽度 */
  #current-stage {
    width: 100%;
    font-size: 11px;
    line-height: 1.4;
    white-space: nowrap;
    overflow: hidden;
    text-overflow: ellipsis;
  }

  /* 第二行：进度条 + 得分 */
  #progress-bar {
    margin: 0 8px 0 0;
    height: 6px;
  }

  /* 倒计时高度与两行面板对齐 */
  #countdown-timer {
    height: 68px;
  }

  /* 移动端消息字体缩小 */
  #narrative-message,
  #evolution-message {
    font-size: 12px;
    padding: 10px 16px;
    width: 90%;
  }
}

/* === 横屏模式 === */
@media (orientation: landscape) and (max-height: 500px) {
  #info-panel {
    height: 36px;
    padding: 6px 12px;
    top: 8px;
  }
  #control-panel {
    bottom: 8px;
    flex-direction: row;
  }
  .cyberpunk-btn {
    padding: 6px 14px;
    font-size: 11px;
  }
}

/* === 音量控制按钮 === */
#volume-btn {
  position: absolute;
  top: 56px; /* info-panel 下方 */
  right: 16px;
  background: rgba(0,255,255,0.08);
  border: 1px solid rgba(0,255,255,0.3);
  color: var(--neon-cyan);
  font-size: 18px;
  width: 36px;
  height: 36px;
  border-radius: 50%;
  cursor: pointer;
  display: flex;
  align-items: center;
  justify-content: center;
  pointer-events: all;
  transition: all 0.2s;
  z-index: 20;
}
#volume-btn:hover {
  background: rgba(0,255,255,0.2);
  box-shadow: 0 0 12px rgba(0,255,255,0.4);
}