/* ============================================================
   VPNBN · ai.css
   AI 工具加速专题页(zh-CN/chatgpt.html)专属样式。
   只做本页布局与局部工艺,颜色/圆角/字体全部取 base.css 令牌,
   通用组件(tabs/table/card/faq/callout/cta-band)沿用 components.css。
   ============================================================ */

/* ------------------------------------------------------------
   hero
   ------------------------------------------------------------ */
.ai-hero{
  position:relative;
  overflow-x:clip;
  max-width:100%;
  padding-top:52px;
  padding-bottom:56px;
}
.ai-hero::before,
.ai-hero::after{
  content:"";
  position:absolute;
  border-radius:50%;
  pointer-events:none;
  z-index:0;
}
.ai-hero::before{
  top:-150px;
  right:-130px;
  width:min(640px,88vw);
  height:440px;
  background:radial-gradient(closest-side,var(--sh-accent-14),transparent 72%);
}
.ai-hero::after{
  bottom:-170px;
  left:-150px;
  width:min(520px,80vw);
  height:360px;
  background:radial-gradient(closest-side,var(--sh-teal-12),transparent 72%);
}
.ai-hero-inner{
  position:relative;
  z-index:1;
  max-width:1020px;
  margin:0 auto;
  min-width:0;
}
.ai-hero-lead{
  margin:18px 0 0;
  max-width:700px;
  font-size:17.5px;
  line-height:1.72;
  color:var(--text-muted);
}
.ai-hero .btn-row{margin-top:26px}
.ai-hero .fact-strip{
  margin-top:28px;
  justify-content:flex-start;
  border-radius:var(--r-card);
}
.ai-chips{
  display:flex;
  flex-wrap:wrap;
  gap:10px;
  margin:22px 0 0;
  padding:0;
}
.ai-chips li{
  display:inline-flex;
  align-items:center;
  min-height:32px;
  padding:5px 15px;
  border-radius:var(--r-pill);
  background:var(--glass-strong);
  border:1px solid var(--glass-border);
  box-shadow:0 8px 18px -14px var(--sh-accent-14);
  font-family:var(--font-mono);
  font-size:12.5px;
  color:var(--text);
  max-width:100%;
  overflow:hidden;
  text-overflow:ellipsis;
  white-space:nowrap;
}

/* ------------------------------------------------------------
   document column
   ------------------------------------------------------------ */
.ai-doc{
  max-width:1020px;
  margin:0 auto;
  min-width:0;
  padding-top:34px;
}
.ai-sec{margin-top:60px}
.ai-sec:first-of-type{margin-top:0}
.ai-doc h2{
  font-size:clamp(23px,2.6vw,31px);
  line-height:1.26;
  margin:0 0 14px;
}
.ai-sec > p{
  font-size:16.5px;
  line-height:1.82;
  color:var(--text);
  max-width:860px;
}
.ai-doc .ai-note{
  margin:14px 0 0;
  font-size:13.5px;
  line-height:1.72;
  color:var(--text-muted);
}
.ai-doc .ai-note a,
.ai-sec > p a,
.ai-points a{
  color:var(--accent-dark);
  text-decoration:underline;
  text-underline-offset:3px;
}

/* ------------------------------------------------------------
   two-column compare cards
   ------------------------------------------------------------ */
.ai-split .badge{margin-bottom:12px}

/* ------------------------------------------------------------
   dev scenario code blocks
   ------------------------------------------------------------ */
.ai-dev-grid pre{
  margin:14px 0 10px;
  background:var(--bg-panel2);
  border-color:var(--border-soft);
  font-size:12.5px;
}

/* ------------------------------------------------------------
   point list
   ------------------------------------------------------------ */
.ai-points{
  display:grid;
  gap:14px;
  margin:22px 0 0;
  padding:0;
}
.ai-points li{
  min-width:0;
  padding:18px 22px;
  border-radius:var(--r-card);
  background:var(--bg-panel);
  border:1px solid var(--border);
  box-shadow:inset 0 1px 0 var(--text-invert),0 16px 34px -30px var(--sh-neutral-10);
}
.ai-points h3{
  font-size:16.5px;
  margin:0 0 6px;
}
.ai-points p{
  margin:0;
  font-size:15px;
  line-height:1.75;
  color:var(--text-muted);
}

/* ------------------------------------------------------------
   cta band:白底紫字主按钮,保证在紫色渐变上可读
   ------------------------------------------------------------ */
.ai-cta .btn-main{
  background:var(--text-invert);
  color:var(--accent-dark);
  box-shadow:0 16px 30px -18px var(--veil);
}

/* ------------------------------------------------------------
   responsive
   ------------------------------------------------------------ */
@media (max-width:900px){
  .ai-dev-grid{grid-template-columns:minmax(0,1fr)}
}
@media (max-width:768px){
  .ai-hero{padding-top:36px;padding-bottom:40px}
  .ai-hero-lead{font-size:16.5px}
  .ai-doc{padding-top:24px}
  .ai-sec{margin-top:46px}
  .ai-sec > p{font-size:16px}
}
@media (max-width:640px){
  .ai-points li{padding:16px 18px}
  .ai-chips li{font-size:12px}
}