/* ==========================================================================
   VPNFN · ai.css
   AI 工具加速专题页专属样式(仅本页使用,颜色/圆角/字体全部引用 :root 令牌)
   ========================================================================== */

/* ===== 页首 ===== */
.ai-hero{
  position:relative;isolation:isolate;
  overflow-x:clip;max-width:100%;
  padding-block:46px 40px;
}
.ai-hero::before{
  content:"";position:absolute;inset:0;z-index:-1;pointer-events:none;
  background:
    radial-gradient(46% 44% at 50% -4%,var(--halo),transparent 72%),
    radial-gradient(26% 26% at 50% 22%,var(--halo-2),transparent 70%),
    linear-gradient(180deg,transparent 44%,var(--bg) 100%);
}
.ai-hero-inner{
  display:flex;flex-direction:column;align-items:center;text-align:center;
  max-width:880px;margin-inline:auto;
}
.ai-hero h1{margin:18px 0 0}
.ai-hero .lead{margin-top:16px;max-width:64ch}
.ai-hero .fact-row{margin-top:22px;justify-content:center}
.ai-cta{
  margin-top:26px;
  display:flex;flex-wrap:wrap;gap:12px;justify-content:center;align-items:center;
}
.ai-hero-note{margin-top:16px;font-size:13.5px;color:var(--muted-2)}

/* ===== 事实条:补足窄屏左右留白 ===== */
.ai-stats{padding-inline:var(--gutter)}

/* ===== 通用卡片网格 ===== */
.ai-cards{display:grid;grid-template-columns:repeat(auto-fit,minmax(280px,1fr));gap:20px}
.ai-cards>*{min-width:0}
.ai-cards h3{margin-bottom:10px;font-size:18px}
.ai-cards p{font-size:14.5px;line-height:1.75;color:var(--muted);margin:0}

/* ===== 工具卡 ===== */
.tool-grid{display:grid;grid-template-columns:repeat(auto-fit,minmax(240px,1fr));gap:16px}
.tool-grid>*{min-width:0}
.tool-card{
  display:flex;flex-direction:column;gap:10px;min-width:0;
  background:var(--bg-panel);
  border:1px solid var(--border);
  border-radius:var(--r-card);
  padding:20px;
  box-shadow:inset 0 1px 0 var(--highlight),0 16px 30px -26px var(--shadow-ink);
  transition:transform .2s ease,box-shadow .2s ease,border-color .2s ease;
}
.tool-card:hover{
  transform:translateY(-4px);
  border-color:var(--accent-block);
  box-shadow:inset 0 1px 0 var(--highlight),0 28px 44px -26px var(--shadow-g-deep);
}
.tool-card h3{font-size:17px}
.tool-card p{font-size:14px;line-height:1.7;color:var(--muted);margin:0}
.tool-tags{display:flex;flex-wrap:wrap;gap:6px;margin-top:auto;padding-top:4px}

/* ===== 表格里的线路标签行 ===== */
.tag-row{display:inline-flex;flex-wrap:wrap;gap:6px}

/* ===== 线路类型说明 ===== */
.route-legend{
  display:grid;grid-template-columns:repeat(auto-fit,minmax(220px,1fr));
  gap:14px;margin-top:20px;
}
.route-legend div{
  min-width:0;
  background:var(--bg-panel-2);
  border:1px solid var(--border-soft);
  border-radius:var(--r-md);
  padding:16px 18px;
}
.route-legend b{
  display:block;margin-bottom:6px;
  font-family:var(--font-display);font-size:15px;font-weight:800;
}
.route-legend p{font-size:13.5px;line-height:1.7;color:var(--muted);margin:0}

/* ===== 网页端 / API 对照 ===== */
.vs-grid{display:grid;grid-template-columns:1fr 1fr;gap:20px}
.vs-grid>*{min-width:0}
.vs-head{display:flex;align-items:center;gap:10px;margin-bottom:14px}
.vs-head svg{
  width:20px;height:20px;flex:0 0 auto;
  fill:none;stroke:var(--accent);stroke-width:1.9;
  stroke-linecap:round;stroke-linejoin:round;
}
.vs-head h3{margin:0;font-size:18px}
.vs-list{display:flex;flex-direction:column;gap:10px}
.vs-list li{position:relative;padding-left:18px;font-size:14.5px;line-height:1.7;color:var(--muted)}
.vs-list li::before{
  content:"";position:absolute;left:0;top:.66em;
  width:6px;height:6px;border-radius:50%;background:var(--accent);
}

/* ===== 拓扑装饰线(纯装饰,不承载数据) ===== */
.topo-lines{
  display:block;width:100%;height:auto;max-height:150px;
  margin:0 0 16px;
}

/* ===== 响应式 ===== */
@media (max-width:900px){
  .vs-grid{grid-template-columns:1fr}
}

@media (max-width:768px){
  .ai-hero{padding-block:32px 28px}
  .ai-hero h1{margin-top:14px}
  .ai-cta{margin-top:22px}
  .topo-lines{max-height:96px}
}

@media (max-width:640px){
  .ai-cta .btn{width:100%}
  .route-legend div{padding:14px 16px}
}