.crystal-ui {
  /* --- 1. 深色父容器设计 (适配白底环境) --- */
  background: radial-gradient(circle at top right, #1e293b 0%, #0f172a 100%);
  border-radius: 20px;
  padding: 24px 20px 12px 20px;
  margin: 16px 0;
  /* 外阴影与白底隔绝，内阴影增加屏幕质感 */
  box-shadow: 0 12px 36px rgba(0, 0, 0, 0.4), inset 0 1px 1px rgba(255, 255, 255, 0.1);
  border: 1px solid #334155;
  
  /* --- 2. 全局字体排版美化 --- */
  font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', 'PingFang SC', 'Hiragino Sans GB', 'Microsoft YaHei', sans-serif;
  color: #cbd5e1; /* 柔和的浅灰蓝色，久看不累 */
  line-height: 1.7;
  letter-spacing: 0.5px;
  font-size: 15px;
  
  /* 定义水晶主题色 */
  --crystal-bg: rgba(255, 255, 255, 0.04);
  --crystal-bg-hover: rgba(255, 255, 255, 0.08);
  --crystal-border-light: rgba(255, 255, 255, 0.15);
  --crystal-border-dark: rgba(0, 0, 0, 0.2);
  --crystal-glow: rgba(56, 189, 248, 0.5);
  --crystal-text-highlight: #f8fafc;
}

/* 突出显示粗体字，增加面板层级感 */
.crystal-ui b, .crystal-ui strong {
  color: #7dd3fc;
  font-weight: 600;
}

/* --- 折叠容器 (Details) 保持水晶质感 --- */
.crystal-ui details {
  background: linear-gradient(135deg, var(--crystal-bg) 0%, rgba(0,0,0,0.2) 100%);
  backdrop-filter: blur(16px);
  -webkit-backdrop-filter: blur(16px);
  border: 1px solid var(--crystal-border-dark);
  border-top: 1px solid var(--crystal-border-light);
  border-left: 1px solid var(--crystal-border-light);
  border-radius: 14px;
  margin-bottom: 16px;
  box-shadow: 0 8px 32px 0 rgba(0, 0, 0, 0.2);
  overflow: hidden;
  transition: all 0.3s cubic-bezier(0.4, 0, 0.2, 1);
}

/* 展开时的外发光 */
.crystal-ui details[open] {
  box-shadow: 0 0 20px var(--crystal-glow), 0 8px 32px 0 rgba(0, 0, 0, 0.3);
  border-color: rgba(125, 211, 252, 0.3);
  background: linear-gradient(135deg, rgba(255,255,255,0.06) 0%, rgba(0,0,0,0.3) 100%);
}

/* --- 标题栏 (Summary) --- */
.crystal-ui summary {
  padding: 14px 18px;
  font-weight: 600;
  font-size: 1.05em;
  color: var(--crystal-text-highlight);
  cursor: pointer;
  list-style: none;
  display: flex;
  align-items: center;
  background: rgba(255, 255, 255, 0.02);
  transition: all 0.3s ease;
  user-select: none;
}

.crystal-ui summary::-webkit-details-marker { display: none; }

/* 自定义水晶图标 */
.crystal-ui summary::before {
  content: '✦';
  margin-right: 12px;
  color: #38bdf8;
  font-size: 1.3em;
  text-shadow: 0 0 10px var(--crystal-glow);
  transition: transform 0.4s cubic-bezier(0.4, 0, 0.2, 1);
}

.crystal-ui summary:hover {
  background: var(--crystal-bg-hover);
  text-shadow: 0 0 8px var(--crystal-glow);
}

.crystal-ui details[open] summary::before {
  transform: rotate(90deg);
  color: #7dd3fc;
}

.crystal-ui details[open] summary {
  border-bottom: 1px solid rgba(255, 255, 255, 0.08);
  background: rgba(0, 0, 0, 0.2);
}

/* --- 内部内容区排版 --- */
.crystal-ui details > *:not(summary) {
  padding: 16px 20px;
  animation: crystalFadeIn 0.4s ease-out forwards;
}

/* --- 水晶分割线 (HR) --- */
.crystal-ui hr {
  border: 0;
  height: 1px;
  background: linear-gradient(90deg, 
    transparent 0%, 
    rgba(56, 189, 248, 0.3) 20%, 
    rgba(255, 255, 255, 0.9) 50%, 
    rgba(56, 189, 248, 0.3) 80%, 
    transparent 100%);
  margin: 18px 0;
  box-shadow: 0 0 10px var(--crystal-glow);
}

@keyframes crystalFadeIn {
  0% { opacity: 0; transform: translateY(-8px); }
  100% { opacity: 1; transform: translateY(0); }
}