/* =====================================================
   上海铂米瑞光电技术有限公司 — 布局（头部、导航、页脚）
   ===================================================== */

/* 头部 */
.site-header {
  position: sticky;
  top: 0;
  z-index: 50;
  background-color: #000000;
  color: #ffffff;
  box-shadow: 0 2px 12px rgba(0, 0, 0, 0.3);
  border-bottom: 1px solid #222222;
}

.header-inner {
  display: flex;
  align-items: center;
  justify-content: space-between;
  height: 72px;
  position: relative;
}

/* Logo */
.logo {
  display: flex;
  align-items: center;
  color: #ffffff;
  font-weight: var(--font-weight-medium);
  font-size: 1.05rem;
  letter-spacing: 0.04em;
  flex-shrink: 0;
}

.logo svg, .logo img {
  height: 40px;
  width: auto;
  margin-right: 12px;
}

.logo:hover, .logo:focus {
  color: var(--accent);
  text-decoration: none;
}

.logo-text {
  white-space: nowrap;
}

/* 汉堡菜单按钮 */
.menu-toggle {
  display: flex;
  align-items: center;
  justify-content: center;
  width: 44px;
  height: 44px;
  padding: 0;
  background: transparent;
  border: 1px solid rgba(255, 255, 255, 0.22);
  border-radius: var(--radius-sm);
  cursor: pointer;
  order: 3;
}

.hamburger, .hamburger::before, .hamburger::after {
  display: block;
  width: 22px;
  height: 2px;
  background-color: #ffffff;
  transition: transform var(--transition), opacity var(--transition);
}

.hamburger {
  position: relative;
}

.hamburger::before, .hamburger::after {
  content: '';
  position: absolute;
  left: 0;
}

.hamburger::before { top: -7px; }
.hamburger::after { top: 7px; }

.menu-open .hamburger {
  background-color: transparent;
}

.menu-open .hamburger::before {
  top: 0;
  transform: rotate(45deg);
}

.menu-open .hamburger::after {
  top: 0;
  transform: rotate(-45deg);
}

/* 主导航【移动端侧边抽屉，同步黑色背景白色文字】 */
.primary-nav {
  position: fixed;
  top: 72px;
  left: 0;
  right: 0;
  bottom: 0;
  background-color: #000000;
  padding: var(--space-md);
  transform: translateX(100%);
  transition: transform var(--transition);
  overflow-y: auto;
  order: 2;
  border-top: 1px solid #222222;
}

.menu-open .primary-nav {
  transform: translateX(0);
}

.nav-list {
  list-style: none;
  margin: 0;
  padding: 0;
  display: flex;
  flex-direction: column;
  gap: var(--space-xs);
}

.nav-list a, .nav-list button {
  display: block;
  width: 100%;
  padding: 12px 0;
  color: #ffffff;
  font-size: 1rem;
  font-weight: var(--font-weight-regular);
  letter-spacing: var(--letter-spacing-wide);
  text-align: left;
  background: transparent;
  border: none;
  cursor: pointer;
  font-family: inherit;
}

.nav-list a:hover, .nav-list a:focus,
.nav-list button:hover, .nav-list button:focus {
  color: var(--accent);
  text-decoration: none;
}

/* 下拉菜单（移动端为手风琴） */
.has-dropdown {
  position: relative;
}

.dropdown {
  list-style: none;
  margin: 0;
  padding: 0 0 0 var(--space-md);
  display: none;
}

.dropdown.open {
  display: block;
}

.dropdown li {
  margin-top: 2px;
}

.dropdown .dropdown__group-title {
  display: block;
  padding: 14px 0 6px;
  color: #bbbbbb;
  font-size: 0.8rem;
  letter-spacing: var(--letter-spacing-wider);
  text-transform: uppercase;
}

.dropdown a {
  padding: 8px 0;
  font-size: 0.95rem;
  letter-spacing: 0.04em;
  color: #cccccc;
}

.dropdown a:hover, .dropdown a:focus {
  color: var(--accent);
}

/* 语言切换器【适配黑色导航栏】 */
.lang-switcher {
  display: flex;
  align-items: center;
  gap: 6px;
}

.lang-btn {
  padding: 6px 10px;
  background: transparent;
  border: 1px solid rgba(255, 255, 255, 0.22);
  color: #cccccc;
  font-size: 0.8rem;
  font-weight: var(--font-weight-medium);
  letter-spacing: 0.06em;
  cursor: pointer;
  border-radius: var(--radius-sm);
  transition: all var(--transition);
}

.lang-btn.active, .lang-btn:hover, .lang-btn:focus {
  background: rgba(255, 255, 255, 0.12);
  color: #ffffff;
  border-color: rgba(255, 255, 255, 0.4);
}

.lang-divider {
  color: rgba(255, 255, 255, 0.35);
  font-size: 0.8rem;
}

.lang-switcher--desktop {
  display: none;
  order: 2;
}

.lang-switcher--mobile {
  margin-top: var(--space-lg);
  padding-top: var(--space-lg);
  border-top: 1px solid #222222;
}

/* 页脚 */
.site-footer {
  background-color: #F4F6F8;
  color: var(--text-secondary);
  padding: var(--space-2xl) 0 var(--space-lg);
  font-size: 0.9rem;
  border-top: 1px solid var(--border-color);
}

.footer-grid {
  display: grid;
  grid-template-columns: 1fr;
  gap: var(--space-lg);
  margin-bottom: var(--space-xl);
}

.footer-brand .logo {
  margin-bottom: var(--space-md);
}

.footer-brand p {
  color: var(--text-secondary);
  max-width: 320px;
  line-height: 1.8;
}

.footer-links h4 {
  color: var(--text-primary);
  font-size: 0.85rem;
  letter-spacing: var(--letter-spacing-wide);
  margin-bottom: var(--space-md);
  text-transform: uppercase;
  font-weight: var(--font-weight-medium);
}

.footer-links ul {
  list-style: none;
  padding: 0;
  margin: 0;
}

.footer-links li {
  margin-bottom: 10px;
}

.footer-links a {
  color: var(--text-secondary);
  font-size: 0.9rem;
}

.footer-links a:hover, .footer-links a:focus {
  color: var(--accent);
}

.footer-bottom {
  border-top: 1px solid var(--border-color);
  padding-top: var(--space-md);
  display: flex;
  flex-direction: column;
  gap: var(--space-sm);
  text-align: center;
  color: var(--text-muted);
  font-size: 0.85rem;
}