/* ===== 全局样式 ===== */
:root {
  --neutral-gray: rgb(128, 128, 128);
  --glass-dark: rgba(0, 0, 0, 0.3);
  --text-white: #fff;
  --nav-text: #007BFF; /* 新增导航文字颜色变量 */
}

body {
  background: var(--neutral-gray);
  color: var(--text-white); /* 只影响基础文字 */
  min-height: 100vh;
  display: flex;
  flex-direction: column;
  font-family: Arial, sans-serif;
  margin: 0;
  padding-top: 60px;
}

/* ===== 受保护的导航栏样式 ===== */
.site-topbar,
.mobile-nav {
  color: initial; /* 重置为浏览器默认 */
  font-size: 16px; /* 明确设置基准大小 */
}

.site-topbar {
  display: flex;
  justify-content: space-between;
  align-items: center;
  padding: 12px 5%;
  background: var(--glass-dark);
  backdrop-filter: blur(5px);
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  z-index: 1000;
  box-sizing: border-box;
}

.topbar__left, 
.topbar__right {
  display: flex;
  align-items: center;
  gap: 15px;
}

.topbar__center {
  flex-grow: 1;
  text-align: center;
}

.topbar__logo {
  height: 30px;
  width: auto;
  transition: transform 0.2s;
}

.topbar__btn {
  background: none;
  border: none;
  font-size: 22px;
  font-weight: bold;
  line-height: 1;
  padding: 6px;
  border-radius: 4px;
  color: var(--nav-text); /* 使用导航专用颜色 */
  cursor: pointer;
  transition: all 0.15s ease;
}

.topbar__btn:hover {
  background: rgba(255,255,255,0.1);
}

/* ===== 移动导航保护 ===== */
.mobile-nav {
  display: none;
  position: absolute;
  top: 100%;
  left: 0;
  width: 100%;
  background: var(--glass-dark);
  backdrop-filter: blur(10px);
  z-index: 999;
  padding: 10px 0;
}

.mobile-nav.mobile-nav--open {
  display: block;
}

.mobile-nav__list {
  list-style: none;
  margin: 0;
  padding: 0;
}

.mobile-nav__list li {
  padding: 14px 20px;
  border-bottom: 1px solid rgba(255,255,255,0.1);
}

.mobile-nav__list a {
  color: var(--nav-text); /* 使用统一导航色 */
  text-decoration: none;
  display: block;
  font-size: 18px;
  font-weight: bold;
  transition: color 0.2s;
}

.mobile-nav__list a:hover {
  color: #0056b3;
}

/* ===== 产品内容专属样式 ===== */
.series-overview,
.page-content {
  --content-text: var(--text-white); /* 内容文字颜色变量 */
}

.series-card,
.dynamic-model-card,
.tn-section {
  color: var(--content-text);
}

.series-card p,
.series-card h2,
.dynamic-model-card p,
.dynamic-model-card h2,
.tn-section p,
.tn-section h2,
.model-specs,
.model-features {
  color: var(--content-text) !important;
  font-size: 1em !important; /* 固定产品文字大小 */
}

/* C系列专属样式 */
.series-card[href*="series=c"] {
  border-left: 4px solid rgba(100, 181, 246, 0.7);
}

/* ===== 底部栏 ===== */
.site-bottombar {
  display: flex;
  justify-content: center;
  align-items: center;
  gap: 10px;
  padding: 10px 15px;
  cursor: pointer;
  color: initial; /* 保护底部文字颜色 */
}

.bottombar__label {
  font-weight: bold;
  font-size: 15px;
  line-height: 15px;
}

.bottombar__logo {
  height: 25px;
  width: auto;
  filter: brightness(1) invert(0);
}

.site-bottombar:active {
  background: rgba(100,100,255,0.1);
}

.site-bottombar:active .bottombar__label,
.site-bottombar:active .bottombar__logo {
  transform: scale(0.95);
}

/* ===== 响应式设计 ===== */
@media (min-width: 768px) {
  body { padding-top: 70px; }
  .site-topbar { 
    padding: 15px 8%; 
    height: 60px; 
    font-size: 16px; /* 保护导航文字大小 */
  }
  .topbar__logo { height: 35px; }
  .page-content { padding: 30px 8%; }
  .bottombar__logo { height: 18px; }
  
  /* 产品内容网格布局 */
  .series-overview {
    grid-template-columns: repeat(3, 1fr);
  }
  .dynamic-model-card {
    grid-template-columns: 1fr 2fr;
  }
}

/* ===== 工具类 ===== */
.form-group {
  background-color: #808080;
  color: white;
  border: none;
  border-radius: 5px;
  padding: 8px;
}

.protected-nav {
  color: inherit !important;
  font-size: inherit !important;
}