/* ==========================================================================
   VPNNK — ai.css
   AI 工具加速专题页(ai.html)专属样式:章节节奏、步骤序号、要点列表、
   工具卡与建议面板。颜色 / 圆角 / 字体一律引用 base.css 的 :root 令牌。
   ========================================================================== */

.ai-head { padding-top: 36px; }
.ai-head h1 { max-width: 26ch; }
.ai-head .lede { margin-top: 14px; }
.ai-head .ctas { margin-top: 20px; }
.ai-head .fact-row { margin-top: 20px; }

.ai-sec + .ai-sec { padding-top: 46px; }

.ai-lead {
  max-width: 74ch;
  color: var(--text-muted);
  font-size: 15.5px;
}
.ai-lead + .ai-lead { margin-top: 12px; }

.ai-cards { margin-top: 22px; }
.ai-cards .card { display: flex; flex-direction: column; gap: 8px; }
.ai-cards h3 { font-size: 18px; letter-spacing: -.02em; }
.ai-cards p { font-size: 14.5px; color: var(--text-muted); }

.ai-sec .callout { margin-top: 20px; }
.ai-sec .table-scroll { margin-top: 20px; }

.ai-list {
  display: flex;
  flex-direction: column;
  gap: 9px;
  margin-top: 18px;
}
.ai-list li {
  position: relative;
  padding-left: 18px;
  font-size: 15px;
  line-height: 1.6;
  color: var(--text-muted);
  max-width: 78ch;
}
.ai-list li::before {
  content: "";
  position: absolute;
  left: 0;
  top: .62em;
  width: 6px;
  height: 6px;
  border-radius: 50%;
  background: var(--accent);
}
.ai-list b { color: var(--text); font-weight: 600; }

.ai-steps {
  counter-reset: ai-step;
  display: flex;
  flex-direction: column;
  gap: 16px;
  margin-top: 20px;
}
.ai-steps > li {
  position: relative;
  padding-left: 46px;
}
.ai-steps > li::before {
  counter-increment: ai-step;
  content: counter(ai-step);
  position: absolute;
  left: 0;
  top: 0;
  width: 30px;
  height: 30px;
  display: flex;
  align-items: center;
  justify-content: center;
  border-radius: var(--radius-s);
  background: var(--accent-soft);
  border: 1px solid var(--accent-line);
  color: var(--accent-dark);
  font-family: var(--font-mono);
  font-size: 13px;
  font-weight: 700;
}
.ai-steps b {
  display: block;
  font-family: var(--font-display);
  font-size: 16.5px;
  font-weight: 700;
  letter-spacing: -.015em;
}
.ai-steps p {
  margin-top: 4px;
  font-size: 14.5px;
  color: var(--text-muted);
  max-width: 70ch;
}

.ai-sec pre { margin-top: 20px; }
.ai-code-note {
  margin-top: 12px;
  font-size: 13.5px;
  color: var(--text-muted);
  max-width: 74ch;
}

.ai-advice { margin-top: 22px; }
.ai-advice h3 { margin-bottom: 10px; }
.ai-advice p { font-size: 14.5px; color: var(--text-muted); max-width: 78ch; }
.ai-advice .fact-row { margin-top: 16px; }

.ai-links {
  display: flex;
  flex-wrap: wrap;
  gap: 10px 24px;
  margin-top: 18px;
}

@media (max-width: 768px) {
  .ai-head h1 { max-width: none; }
  .ai-sec + .ai-sec { padding-top: 36px; }
  .ai-lead { font-size: 15px; }
}