/* ============================================================
   网络访问评测实验室 NetAccess Lab — 全站共享基础样式
   来源:claude.ai/design 项目「2026年七月VPN推荐」(已中性化重构)
   内容:字体栈、全局重置、关键帧动画、悬停效果类、
        全站导航 / 页脚 / 面包屑 / 数据说明等共享组件、移动端适配
   ============================================================ */

/* —— 字体:系统字体栈,无外部请求(原 Google Fonts 已移除)——
   若本机装有 Noto Sans SC / JetBrains Mono / Space Grotesk 会优先使用,
   否则回退到各平台高质量系统字体,视觉层级不变。 */
:root {
  --font-sans: -apple-system, BlinkMacSystemFont, "Segoe UI", "PingFang SC",
               "Hiragino Sans GB", "Microsoft YaHei", "Noto Sans SC", sans-serif;
  --font-mono: ui-monospace, "SF Mono", "JetBrains Mono", "Cascadia Code",
               Menlo, Consolas, "Liberation Mono", monospace;
  --font-num: "Space Grotesk", "SF Pro Display", "Segoe UI", -apple-system,
              system-ui, sans-serif;
}

html, body { margin: 0; padding: 0; }
* { box-sizing: border-box; }
body { background: #05070D; color: #E6ECF3; font-family: var(--font-sans); }
a { color: inherit; text-decoration: none; }
::selection { background: #4FF0D4; color: #04120E; }
::-webkit-scrollbar { width: 10px; height: 10px; }
::-webkit-scrollbar-track { background: #05070D; }
::-webkit-scrollbar-thumb { background: #1A2438; border-radius: 6px; }

/* —— 关键帧动画(与设计稿一致)—— */
@keyframes rise { from { opacity: 0; transform: translateY(22px); } to { opacity: 1; transform: none; } }
@keyframes glowPulse { 0%, 100% { opacity: .45; } 50% { opacity: 1; } }
@keyframes sweep { to { transform: rotate(360deg); } }
@keyframes scan { 0% { transform: translateY(-10vh); } 100% { transform: translateY(105vh); } }
@keyframes blip { 0%, 100% { opacity: .15; transform: scale(.6); } 50% { opacity: 1; transform: scale(1.15); } }
@keyframes gridDrift { from { background-position: 0 0, 0 0; } to { background-position: 52px 52px, 52px 52px; } }
@keyframes ringSpin { to { transform: rotate(-360deg); } }
@keyframes drawIn { from { opacity: 0; transform: scale(.85); } to { opacity: 1; transform: none; } }

/* —— 悬停效果类(对应设计稿的 style-hover 属性)—— */
.hv-text:hover { color: #E6ECF3 !important; }
.hv-white:hover { color: #fff !important; }
.hv-lift1:hover { transform: translateY(-1px); }
.hv-lift2:hover { transform: translateY(-2px); }
.hv-card:hover { border-color: rgba(79, 240, 212, 0.4) !important; transform: translateY(-3px); }
.hv-cell:hover { background: #0C1120 !important; }
.hv-bg03:hover { background: rgba(79, 240, 212, 0.03) !important; }
.hv-bg04:hover { background: rgba(79, 240, 212, 0.04) !important; }
.hv-bg08:hover { background: rgba(79, 240, 212, 0.08) !important; }
.hv-bg10:hover { background: rgba(79, 240, 212, 0.1) !important; }
.hv-bg12:hover { background: rgba(79, 240, 212, 0.12) !important; }

/* ============================================================
   全站共享组件
   ============================================================ */

/* —— 跳到正文(键盘 / 读屏用户)—— */
.skip-link {
  position: absolute; left: -9999px; top: 0; z-index: 100;
  background: #4FF0D4; color: #04120E; font-weight: 600; font-size: 14px;
  padding: 10px 18px; border-radius: 0 0 10px 0;
}
.skip-link:focus { left: 0; }

/* —— 顶部导航 —— */
.site-header {
  position: sticky; top: 0; z-index: 50;
  background: rgba(5, 7, 13, 0.72);
  backdrop-filter: blur(14px); -webkit-backdrop-filter: blur(14px);
  border-bottom: 1px solid rgba(120, 160, 200, 0.12);
}
.nav-bar {
  max-width: 1200px; margin: 0 auto; padding: 0 40px; height: 66px;
  display: flex; align-items: center; justify-content: space-between; gap: 18px;
}
.brand { display: flex; align-items: center; gap: 11px; flex-shrink: 0; }
.brand-text { display: flex; flex-direction: column; line-height: 1.05; gap: 8px; }
.brand-name { font-weight: 700; font-size: 15px; letter-spacing: 0.5px; }
.brand-sub { font-family: var(--font-mono); font-size: 9px; letter-spacing: 2.5px; color: #5FE0C8; }

.nav-links {
  display: flex; align-items: center; gap: 22px;
  font-size: 13.5px; color: #9AA6B8; font-weight: 400; white-space: nowrap;
}
.nav-links > a:hover { color: #E6ECF3; }
.nav-links > a[aria-current="page"] { color: #4FF0D4; }

/* —— 桌面分组下拉:<details> 实现,无 JS 依赖、键盘可达,
      链接始终在 DOM 中可被抓取;nav.js 仅做“互斥展开 / 点外关闭”增强 —— */
.nav-group { position: relative; }
.nav-group > summary {
  list-style: none; cursor: pointer; user-select: none;
  display: inline-flex; align-items: center; gap: 6px;
  color: inherit; padding: 6px 2px;
}
.nav-group > summary::-webkit-details-marker { display: none; }
.nav-group > summary::after {
  content: ""; width: 7px; height: 7px; flex-shrink: 0; margin-top: -3px;
  border-right: 1.4px solid currentColor; border-bottom: 1.4px solid currentColor;
  transform: rotate(45deg); transition: transform .15s; opacity: 0.75;
}
.nav-group[open] > summary::after { transform: rotate(225deg); margin-top: 3px; }
.nav-group > summary:hover { color: #E6ECF3; }
.nav-group[open] > summary { color: #E6ECF3; }
/* 当前页所在分组:与单链接的 aria-current 同色,保证“当前页状态”在收起时也可见 */
.nav-group.cur > summary { color: #4FF0D4; }
.nav-panel {
  position: absolute; left: 50%; transform: translateX(-50%);
  top: calc(100% + 16px); min-width: 216px; z-index: 60;
  display: flex; flex-direction: column; gap: 2px; padding: 10px;
  background: #0A0F1B; border: 1px solid rgba(120, 160, 200, 0.25); border-radius: 14px;
  box-shadow: 0 18px 50px rgba(0, 0, 0, 0.55);
}
.nav-panel::before { /* 补齐 summary 与面板间的悬停间隙 */
  content: ""; position: absolute; left: 0; right: 0; top: -16px; height: 16px;
}
.nav-panel a { padding: 10px 14px; border-radius: 9px; font-size: 13.5px; color: #C6D0DE; white-space: nowrap; }
.nav-panel a:hover { background: rgba(79, 240, 212, 0.06); color: #fff; }
.nav-panel a[aria-current="page"] { color: #4FF0D4; background: rgba(79, 240, 212, 0.07); }
.nav-panel .nav-panel-note {
  font-size: 11.5px; color: #6E7A8C; padding: 4px 14px 8px; line-height: 1.6; white-space: normal;
}

.nav-side { display: flex; align-items: center; gap: 14px; flex-shrink: 0; }
.nav-live {
  display: flex; align-items: center; gap: 7px;
  font-family: var(--font-mono); font-size: 11px; color: #6E7A8C; letter-spacing: 1px;
}
.live-dot {
  width: 6px; height: 6px; border-radius: 50%; background: #4FF0D4;
  box-shadow: 0 0 8px #4FF0D4; animation: glowPulse 1.8s ease-in-out infinite;
}

/* —— 移动端菜单:<details> 实现,无 JS、键盘可达 —— */
.nav-mobile { display: none; position: relative; }
.nav-mobile > summary {
  list-style: none; cursor: pointer; user-select: none;
  display: inline-flex; align-items: center; gap: 8px;
  font-size: 13px; font-weight: 500; color: #CFEFE8;
  border: 1px solid rgba(79, 240, 212, 0.3); background: rgba(79, 240, 212, 0.05);
  padding: 8px 14px; border-radius: 9px;
}
.nav-mobile > summary::-webkit-details-marker { display: none; }
.nav-mobile > summary::before { content: "☰"; font-size: 13px; color: #4FF0D4; }
.nav-mobile[open] > summary::before { content: "✕"; }
.nav-mobile-panel {
  position: absolute; right: 0; top: calc(100% + 12px); min-width: 220px;
  display: flex; flex-direction: column; gap: 2px; padding: 10px;
  background: #0A0F1B; border: 1px solid rgba(120, 160, 200, 0.25); border-radius: 14px;
  box-shadow: 0 18px 50px rgba(0, 0, 0, 0.55);
  max-height: calc(100vh - 90px); overflow-y: auto; /* 小屏菜单超高时面板内滚动 */
}
.nav-mobile-panel a { padding: 11px 14px; border-radius: 9px; font-size: 14.5px; color: #C6D0DE; }
.nav-mobile-panel a:hover { background: rgba(79, 240, 212, 0.06); color: #fff; }
.nav-mobile-panel a[aria-current="page"] { color: #4FF0D4; background: rgba(79, 240, 212, 0.07); }
.nav-mobile-group {
  font-family: var(--font-mono); font-size: 10px; letter-spacing: 1.5px; color: #5FE0C8;
  padding: 12px 14px 4px; border-top: 1px solid rgba(120, 160, 200, 0.12); margin-top: 6px;
}
.nav-mobile-group:first-child { border-top: none; margin-top: 0; padding-top: 4px; }

/* —— FAQ 手风琴(details/summary,跨浏览器统一展开指示)—— */
.faq-q { list-style: none; display: flex; align-items: baseline; justify-content: space-between; gap: 18px; }
.faq-q::-webkit-details-marker { display: none; }
.faq-q::after { content: "+"; color: #4FF0D4; font-size: 20px; font-weight: 300; line-height: 1; flex-shrink: 0; }
details[open] > .faq-q::after { content: "−"; }

/* —— 面包屑 —— */
.crumbs {
  font-family: var(--font-mono); font-size: 11.5px; letter-spacing: 1.5px;
  color: #6E7A8C; display: flex; flex-wrap: wrap; gap: 8px; align-items: center;
}
.crumbs a { color: #5FE0C8; }
.crumbs a:hover { color: #4FF0D4; }
.crumbs [aria-current="page"] { color: #B9C4D4; }

/* —— 数据说明(演示数据口径与局限披露)—— */
.data-note {
  border: 1px solid rgba(255, 180, 84, 0.28); border-radius: 12px;
  background: rgba(255, 180, 84, 0.05);
  padding: 14px 18px; font-size: 13px; color: #B9C4D4; line-height: 1.75;
}
.data-note strong { color: #FFB454; font-weight: 600; }
.data-note a { color: #4FF0D4; }

/* —— 章节眉标(mono 小标)—— */
.sec-tag {
  font-family: var(--font-mono); font-size: 11px; letter-spacing: 2.5px; color: #5FE0C8;
}

/* —— 目录 —— */
.toc {
  border: 1px solid rgba(120, 160, 200, 0.14); border-radius: 14px;
  background: linear-gradient(180deg, rgba(255, 255, 255, 0.025), rgba(255, 255, 255, 0.005));
  padding: 20px 24px;
}
.toc ol { margin: 10px 0 0; padding: 0 0 0 2px; list-style: none; counter-reset: toc; }
.toc li { counter-increment: toc; margin: 8px 0; font-size: 14px; }
.toc li::before {
  content: counter(toc, decimal-leading-zero);
  font-family: var(--font-mono); font-size: 11px; color: #5FE0C8; margin-right: 12px;
}
.toc a { color: #B9C4D4; }
.toc a:hover { color: #4FF0D4; }

/* —— 首页六主题入口:桌面 3×2,中屏 2×3,小屏单列 —— */
.hub6 { display: grid; grid-template-columns: repeat(3, 1fr); gap: 16px; }

/* —— 静态对照表(机场 vs VPN 等)—— */
.table-scroll { overflow-x: auto; }
.cmp-table { width: 100%; border-collapse: collapse; font-size: 14px; min-width: 560px; }
.cmp-table th, .cmp-table td {
  text-align: left; padding: 13px 16px; border-bottom: 1px solid rgba(120, 160, 200, 0.12);
  vertical-align: top; line-height: 1.65;
}
.cmp-table th {
  font-family: var(--font-mono); font-size: 11px; letter-spacing: 1px; font-weight: 500;
  color: #5FE0C8; background: rgba(79, 240, 212, 0.05);
  border-bottom: 1px solid rgba(79, 240, 212, 0.2); white-space: nowrap;
}
.cmp-table td:first-child { color: #8994A6; white-space: nowrap; }
.cmp-table td { color: #C6D0DE; }

/* —— 风险 / 提示卡 —— */
.notice-warn {
  border: 1px solid rgba(255, 122, 107, 0.3); border-radius: 12px;
  background: rgba(255, 122, 107, 0.05); padding: 16px 20px;
  font-size: 14px; color: #C6D0DE; line-height: 1.75;
}
.notice-warn strong { color: #FF9A8C; }

/* —— 正文排版(指南类页面)—— */
.prose h2 { font-weight: 700; font-size: 30px; letter-spacing: -0.5px; margin: 64px 0 18px; line-height: 1.3; }
.prose h3 { font-weight: 700; font-size: 20px; letter-spacing: -0.3px; margin: 38px 0 14px; }
.prose p { font-size: 16px; color: #A8B2C2; line-height: 1.9; margin: 0 0 18px; }
.prose ul, .prose ol { margin: 0 0 18px; padding-left: 22px; color: #A8B2C2; font-size: 15.5px; line-height: 1.9; }
.prose li { margin: 7px 0; }
.prose li::marker { color: #4FF0D4; }
.prose a { color: #4FF0D4; }
.prose strong { color: #E6ECF3; font-weight: 600; }
.prose .hl { color: #4FF0D4; }

/* —— 页脚 —— */
.site-footer { position: relative; z-index: 1; max-width: 1200px; margin: 96px auto 0; padding: 0 40px; }
.footer-top {
  border-top: 1px solid rgba(120, 160, 200, 0.14); padding: 48px 0 20px;
  display: flex; flex-wrap: wrap; justify-content: space-between; gap: 36px; align-items: flex-start;
}
.footer-brand { max-width: 340px; }
.footer-brand p { font-size: 13px; line-height: 1.7; margin: 12px 0 0; color: #7E8A9C; }
.footer-cols { display: flex; flex-wrap: wrap; gap: 48px; }
.footer-col { display: flex; flex-direction: column; gap: 11px; font-size: 13px; color: #9AA6B8; }
.footer-col-title {
  font-family: var(--font-mono); color: #5FE0C8; font-size: 10px; letter-spacing: 1.5px; margin-bottom: 2px;
}
.footer-col a:hover { color: #fff; }
.footer-legal {
  border-top: 1px solid rgba(120, 160, 200, 0.1); padding: 20px 0 40px; margin-top: 28px;
  display: flex; flex-wrap: wrap; justify-content: space-between; gap: 14px;
  font-family: var(--font-mono); font-size: 11px; color: #4C5666; line-height: 1.8;
}

/* ============================================================
   移动端适配
   仅做栅格塌缩与留白/字号收敛,不改变视觉语言。
   ============================================================ */
@media (max-width: 1120px) {
  .nav-live { display: none; }
}

@media (max-width: 960px) {
  .nav-links { display: none; }
  .nav-mobile { display: block; }
  .hero-grid { grid-template-columns: 1fr !important; gap: 40px !important; padding-top: 64px !important; }
  .feat-grid { grid-template-columns: 1fr !important; }
  .method-grid { grid-template-columns: repeat(2, 1fr) !important; }
  .featpick-grid { grid-template-columns: 1fr !important; padding: 32px 28px !important; }
  .rank-grid { grid-template-columns: repeat(2, 1fr) !important; }
  .review-grid { grid-template-columns: 1fr !important; gap: 28px !important; }
  .compare-grid { grid-template-columns: 1fr !important; }
  .hub-grid { grid-template-columns: repeat(2, 1fr) !important; }
  .hub6 { grid-template-columns: repeat(2, 1fr) !important; }
  .two-col { grid-template-columns: 1fr !important; }
  .persona-grid { grid-template-columns: repeat(2, 1fr) !important; }
}

@media (max-width: 640px) {
  .wrap { padding-left: 22px !important; padding-right: 22px !important; }
  .nav-bar { padding: 0 22px; }
  .page-h1 { font-size: 34px !important; letter-spacing: -1px !important; }
  .method-grid, .rank-grid, .hub-grid, .persona-grid { grid-template-columns: 1fr !important; }
  .hub6 { grid-template-columns: 1fr !important; }
  .feat-pad { padding: 32px 24px !important; }
  .cta-card { padding: 34px 24px !important; }
  .review-body { padding-left: 6px !important; }
  .guide-row { flex-wrap: wrap; }
  .guide-row > div:first-of-type { width: auto !important; }
  .prose h2 { font-size: 24px; }
  .step-row { flex-direction: column; gap: 10px !important; }
}