/* =====================================================================
 *  SEO 落地页公共样式（index.html 主工具页不依赖此文件）
 *  设计目标：极简、无外部依赖、首屏快（利于百度收录与移动端体验）
 * ===================================================================== */

:root {
  --brand: #7c3aed;
  --brand-d: #6d28d9;
  --brand-l: #f5f3ff;
  --ink: #1f2937;
  --ink-2: #374151;
  --gray: #6b7280;
  --gray-2: #9ca3af;
  --line: #ebe7fa;
  --bg: #faf9ff;
}

* { box-sizing: border-box; }

html { -webkit-text-size-adjust: 100%; }

body {
  margin: 0;
  background: var(--bg);
  color: var(--ink);
  font: 16px/1.8 -apple-system, BlinkMacSystemFont, "Segoe UI", "PingFang SC",
        "Hiragino Sans GB", "Microsoft YaHei", "Helvetica Neue", Arial, sans-serif;
}

img { max-width: 100%; height: auto; }

a { color: var(--brand); text-decoration: none; }
a:hover { text-decoration: underline; }

.wrap { max-width: 860px; margin: 0 auto; padding: 0 18px; }

/* ---------- 顶部导航 ---------- */
.top {
  position: sticky; top: 0; z-index: 20;
  background: rgba(255, 255, 255, .94);
  backdrop-filter: blur(8px);
  border-bottom: 1px solid var(--line);
}
.top .wrap {
  max-width: 1040px; height: 60px;
  display: flex; align-items: center; justify-content: space-between; gap: 12px;
}
.brand { display: flex; align-items: center; gap: 10px; color: var(--ink); font-weight: 800; }
.brand:hover { text-decoration: none; }
.brand img { width: 32px; height: 32px; border-radius: 9px; display: block; }
.brand span { font-size: 15px; }

/* ---------- 按钮 ---------- */
.btn {
  display: inline-block; border: 0; cursor: pointer;
  padding: 10px 22px; border-radius: 999px;
  font-size: 15px; font-weight: 700; color: #fff;
  background: linear-gradient(135deg, #7c3aed, #6d28d9);
  box-shadow: 0 10px 22px -10px rgba(124, 58, 237, .85);
  transition: filter .15s ease, transform .15s ease;
}
.btn:hover { filter: brightness(1.07); text-decoration: none; transform: translateY(-1px); }
.btn-sm { padding: 8px 16px; font-size: 14px; }
.btn-lg { padding: 14px 32px; font-size: 17px; }
.btn-ghost {
  background: #fff; color: var(--brand);
  border: 1px solid #ddd6fe; box-shadow: none; font-weight: 700;
}

/* ---------- 首屏 ---------- */
.hero { padding: 34px 0 8px; }
.crumb { font-size: 13px; color: var(--gray-2); margin-bottom: 12px; }
.crumb a { color: var(--gray); }

h1 {
  font-size: 30px; line-height: 1.35; margin: 0 0 12px;
  letter-spacing: -.3px; font-weight: 800;
}
h2 {
  font-size: 21px; line-height: 1.45; margin: 34px 0 10px; font-weight: 800;
  padding-left: 12px; border-left: 4px solid var(--brand); border-radius: 2px;
}
h3 { font-size: 17px; margin: 20px 0 6px; font-weight: 700; }

.lead { font-size: 17px; color: var(--ink-2); margin: 0 0 18px; }

.chips { list-style: none; padding: 0; margin: 16px 0 0; display: flex; flex-wrap: wrap; gap: 8px; }
.chips li {
  font-size: 13px; font-weight: 600; color: var(--brand-d);
  background: var(--brand-l); border: 1px solid var(--line);
  border-radius: 999px; padding: 5px 12px;
}

/* ---------- 卡片 / 提示块 ---------- */
.card {
  background: #fff; border: 1px solid var(--line); border-radius: 16px;
  padding: 18px 20px; margin: 18px 0;
  box-shadow: 0 6px 18px -14px rgba(76, 29, 149, .5);
}
.cta-card { text-align: center; padding: 26px 20px; }
.cta-card .btn { margin-top: 12px; }
.cta-card .note { font-size: 13px; color: var(--gray-2); margin: 10px 0 0; }

.tip {
  background: #f0fdf4; border: 1px solid #bbf7d0; color: #166534;
  border-radius: 12px; padding: 12px 16px; font-size: 15px; margin: 16px 0;
}
.warn {
  background: #fffbeb; border: 1px solid #fde68a; color: #92400e;
  border-radius: 12px; padding: 12px 16px; font-size: 15px; margin: 16px 0;
}

/* ---------- 步骤 ---------- */
.steps { counter-reset: s; list-style: none; padding: 0; margin: 14px 0; }
.steps > li {
  position: relative; padding: 0 0 14px 42px; margin: 0;
}
.steps > li::before {
  counter-increment: s; content: counter(s);
  position: absolute; left: 0; top: 2px;
  width: 26px; height: 26px; border-radius: 50%;
  background: var(--brand); color: #fff;
  font-size: 13px; font-weight: 800; line-height: 26px; text-align: center;
}
.steps > li b { display: block; }

/* ---------- 表格 ---------- */
.table-scroll { overflow-x: auto; margin: 16px 0; }
table { width: 100%; border-collapse: collapse; font-size: 15px; min-width: 520px; }
th, td { border: 1px solid var(--line); padding: 9px 12px; text-align: left; vertical-align: top; }
th { background: var(--brand-l); font-weight: 700; white-space: nowrap; }
td.yes { color: #15803d; font-weight: 700; }
td.no { color: #b91c1c; font-weight: 700; }

/* ---------- FAQ ---------- */
.faq { margin: 14px 0 0; }
.faq details {
  background: #fff; border: 1px solid var(--line); border-radius: 12px;
  padding: 12px 16px; margin-bottom: 8px;
}
.faq summary { cursor: pointer; font-weight: 700; color: var(--ink); font-size: 16px; }
.faq summary::marker { color: var(--brand); }
.faq details[open] summary { color: var(--brand-d); }
.faq p { margin: 10px 0 0; color: var(--ink-2); font-size: 15px; }

/* ---------- 相关链接 ---------- */
.related { list-style: none; padding: 0; margin: 12px 0 0; }
.related li { padding: 9px 0; border-bottom: 1px dashed var(--line); }
.related li:last-child { border-bottom: 0; }
.related a { font-weight: 600; }
.related em { display: block; font-style: normal; font-size: 13px; color: var(--gray-2); }

/* ---------- 页脚 ---------- */
.foot {
  margin-top: 44px; padding: 26px 0 40px;
  border-top: 1px solid var(--line);
  background: #fff; color: var(--gray); font-size: 13px;
}
.foot .wrap { max-width: 1040px; }
.foot-links { display: flex; flex-wrap: wrap; gap: 8px 18px; margin: 0 0 10px; padding: 0; list-style: none; }
.foot p { margin: 4px 0; }

/* ---------- 移动端 ---------- */
@media (max-width: 640px) {
  h1 { font-size: 24px; }
  h2 { font-size: 19px; }
  .lead { font-size: 16px; }
  .hero { padding: 22px 0 4px; }
  .brand span { font-size: 14px; }
  .top .wrap { height: 56px; }
}