/* ═══════════════════════════════════════════════════════════════
   aceworld.top — 毛玻璃导航组件 (Glassmorphism Nav)
   版本: v2.0
   特性: Fixed top / backdrop-blur / 底线动效 / 汉堡菜单
   ═══════════════════════════════════════════════════════════════ */

/* ─── 导航容器 ─── */
.site-nav {
  position: fixed;
  top: 0;
  left: 0;
  width: 100%;
  height: var(--nav-height);
  z-index: var(--z-nav);
  display: flex;
  align-items: center;
  transition: background var(--duration-normal) var(--ease-out);
}

/* 毛玻璃效果（滚动后激活或始终开启） */
.site-nav.scrolled,
.site-nav.nav-glass {
  background: var(--glass-bg);
  backdrop-filter: blur(var(--glass-blur));
  -webkit-backdrop-filter: blur(var(--glass-blur));
  border-bottom: 1px solid var(--glass-border);
  box-shadow: var(--glass-shadow);
}

/* ─── 导航内部布局 ─── */
.nav-inner {
  display: flex;
  align-items: center;
  justify-content: space-between;
  width: 100%;
  max-width: var(--content-max-width);
  margin: 0 auto;
  padding: 0 var(--space-8);
  height: 100%;
}

@media (min-width: 768px) {
  .nav-inner {
    padding: 0 var(--space-9);
  }
}

/* ─── Logo ─── */
.nav-logo {
  display: flex;
  align-items: center;
  gap: var(--space-3);
  font-size: var(--text-h3);
  font-weight: var(--weight-bold);
  color: var(--text-primary);
  letter-spacing: var(--tracking-h2);
  transition: opacity var(--duration-fast) var(--ease-out);
  flex-shrink: 0;
}

.nav-logo:hover {
  opacity: 0.85;
}

.nav-logo-icon {
  width: 28px;
  height: 28px;
  border-radius: var(--radius-sm);
  background: linear-gradient(135deg, var(--brand-primary), var(--brand-accent));
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 14px;
  color: #fff;
  font-weight: var(--weight-bold);
}

/* ─── 导航链接列表 ─── */
.nav-links {
  display: flex;
  align-items: center;
  gap: var(--space-2);
}

/* ─── 单个导航链接 ─── */
.nav-link {
  position: relative;
  display: inline-flex;
  align-items: center;
  height: 32px;
  padding: 0 var(--space-3);
  font-size: var(--text-body-sm);
  font-weight: var(--weight-medium);
  color: var(--text-tertiary);
  letter-spacing: -0.01em;
  white-space: nowrap;
  border-radius: var(--radius-md);
  transition:
    color var(--duration-fast) var(--ease-out),
    background var(--duration-fast) var(--ease-out);
  -webkit-user-select: none;
  user-select: none;
}

.nav-link:hover {
  color: var(--text-primary);
  background: rgba(255, 255, 255, 0.06);
}

/* 当前激活链接 */
.nav-link.active {
  color: var(--text-primary);
}

/* ─── Hover 底线动效 ─── */
.nav-link::after {
  content: '';
  position: absolute;
  bottom: 2px;
  left: 50%;
  transform: translateX(-50%) scaleX(0);
  width: calc(100% - var(--space-3) * 2);
  height: 1.5px;
  background: var(--brand-primary);
  border-radius: var(--radius-pill);
  transition: transform var(--duration-fast) var(--ease-spring);
  transform-origin: center;
}

.nav-link:hover::after,
.nav-link.active::after {
  transform: translateX(-50%) scaleX(1);
}

/* ─── 桌面端：显示全部链接 ─── */
@media (min-width: 769px) {
  .nav-links {
    display: flex;
  }
}

/* ─── 桌面端显式隐藏移动菜单 ─── */
@media (min-width: 769px) {
  .nav-mobile-panel {
    display: none !important;
  }
  .nav-hamburger {
    display: none;
  }
}

/* ─── 移动端 (<=768px)：汉堡菜单 ─── */
@media (max-width: 768px) {
  .nav-links {
    display: none;
  }

  /* 汉堡按钮 */
  .nav-hamburger {
    display: flex;
    align-items: center;
    justify-content: center;
    width: 44px;
    height: 44px;
    cursor: pointer;
    border-radius: var(--radius-md);
    transition: background var(--duration-fast) var(--ease-out);
    -webkit-tap-highlight-color: transparent;
  }

  .nav-hamburger:hover {
    background: rgba(255, 255, 255, 0.08);
  }

  .nav-hamburger-line {
    position: relative;
    width: 20px;
    height: 1.5px;
    background: var(--text-primary);
    border-radius: var(--radius-pill);
    transition:
      background var(--duration-fast) var(--ease-out),
      transform var(--duration-fast) var(--ease-spring);
  }

  .nav-hamburger-line::before,
  .nav-hamburger-line::after {
    content: '';
    position: absolute;
    left: 0;
    width: 20px;
    height: 1.5px;
    background: var(--text-primary);
    border-radius: var(--radius-pill);
    transition: transform var(--duration-fast) var(--ease-spring);
  }

  .nav-hamburger-line::before {
    top: -6px;
  }

  .nav-hamburger-line::after {
    top: 6px;
  }

  /* 激活态：X 形 */
  .nav-hamburger.active .nav-hamburger-line {
    background: transparent;
  }

  .nav-hamburger.active .nav-hamburger-line::before {
    transform: translateY(6px) rotate(45deg);
  }

  .nav-hamburger.active .nav-hamburger-line::after {
    transform: translateY(-6px) rotate(-45deg);
  }

  /* ─── 移动端菜单面板 ─── */
  .nav-mobile-panel {
    position: fixed;
    top: var(--nav-height);
    left: 0;
    width: 100%;
    height: calc(100vh - var(--nav-height));
    height: calc(100dvh - var(--nav-height));
    background: rgba(8, 9, 10, 0.96);
    backdrop-filter: blur(24px);
    -webkit-backdrop-filter: blur(24px);
    display: flex;
    flex-direction: column;
    align-items: center;
    justify-content: flex-start;
    padding-top: var(--space-9);
    opacity: 0;
    visibility: hidden;
    transform: translateY(-8px);
    transition:
      opacity var(--duration-normal) var(--ease-spring),
      visibility var(--duration-normal) var(--ease-spring),
      transform var(--duration-normal) var(--ease-spring);
    overflow-y: auto;
    z-index: calc(var(--z-nav) - 1);
  }

  .nav-mobile-panel.open {
    opacity: 1;
    visibility: visible;
    transform: translateY(0);
  }

  .nav-mobile-panel .nav-links {
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: var(--space-4);
    width: 100%;
  }

  .nav-mobile-panel .nav-link {
    font-size: var(--text-h2);
    font-weight: var(--weight-regular);
    height: 48px;
    padding: 0 var(--space-8);
    color: var(--text-secondary);
    letter-spacing: var(--tracking-h2);
  }

  .nav-mobile-panel .nav-link:hover {
    color: var(--text-primary);
    background: rgba(255, 255, 255, 0.05);
  }

  .nav-mobile-panel .nav-link.active {
    color: var(--brand-primary);
  }

  .nav-mobile-panel .nav-link::after {
    display: none;
  }
}

/* ─── 小屏手机调优 ─── */
@media (max-width: 480px) {
  .nav-mobile-panel .nav-link {
    font-size: var(--text-h3);
    height: 44px;
  }
}

/* ─── 导航隐藏项标记 (第12项 AI手机资讯) ─── */
.nav-link.nav-hidden-desktop {
  /* 桌面端隐藏，移动端汉堡菜单中展示 */
}

@media (min-width: 769px) {
  .nav-link.nav-hidden-desktop {
    display: none;
  }
}

/* ─── 导航滚动状态检测交互 ─── */
.site-nav {
  --nav-bg-alpha: 0;
  background: rgba(8, 9, 10, 0);
}

.site-nav.scrolled {
  background: var(--glass-bg);
}

/* 顶部时 logo 稍大，滚动后收紧（微妙变化） */
.nav-logo {
  transition:
    opacity var(--duration-fast) var(--ease-out),
    transform var(--duration-fast) var(--ease-out);
}

.site-nav.scrolled .nav-logo {
  transform: scale(0.95);
}