/* SEO Generator base stylesheet. Vanilla CSS, mobile-first, no frameworks. */

:root {
  --color-bg: #ffffff;
  --color-bg-alt: #f7f8fa;
  --color-text: #1a1d24;
  --color-text-muted: #5b6472;
  --color-border: #e4e7ec;
  --color-primary: #2454ff;
  --color-primary-dark: #173bcc;
  --color-warning-bg: #fff7e6;
  --color-warning-border: #ffd591;
  --max-width: 1080px;
  --radius: 10px;
  --font-sans: -apple-system, "Segoe UI", "PingFang SC", "Microsoft YaHei", Roboto, Helvetica, Arial, sans-serif;
}

* {
  box-sizing: border-box;
}

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

body {
  margin: 0;
  font-family: var(--font-sans);
  color: var(--color-text);
  background: var(--color-bg);
  line-height: 1.6;
  font-size: 16px;
}

img {
  max-width: 100%;
  display: block;
}

a {
  color: var(--color-primary);
  text-decoration: none;
}

a:hover {
  text-decoration: underline;
}

.container {
  width: 100%;
  max-width: var(--max-width);
  margin: 0 auto;
  padding: 0 20px;
}

/* Header */
.site-header {
  border-bottom: 1px solid var(--color-border);
  position: sticky;
  top: 0;
  background: var(--color-bg);
  z-index: 50;
}

.site-header .container {
  display: flex;
  align-items: center;
  justify-content: space-between;
  height: 60px;
}

.site-logo {
  font-weight: 700;
  font-size: 1.15rem;
  color: var(--color-text);
}

.site-nav {
  display: none;
  gap: 20px;
}

.site-nav a {
  color: var(--color-text-muted);
  font-size: 0.95rem;
}

.nav-toggle {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  width: 40px;
  height: 40px;
  border: 1px solid var(--color-border);
  border-radius: 8px;
  background: none;
  cursor: pointer;
}

.nav-toggle span {
  display: block;
  width: 18px;
  height: 2px;
  background: var(--color-text);
  position: relative;
}

.nav-toggle span::before,
.nav-toggle span::after {
  content: "";
  position: absolute;
  left: 0;
  width: 18px;
  height: 2px;
  background: var(--color-text);
}

.nav-toggle span::before {
  top: -6px;
}

.nav-toggle span::after {
  top: 6px;
}

.site-nav-mobile {
  display: none;
  flex-direction: column;
  border-top: 1px solid var(--color-border);
  padding: 10px 20px 16px;
}

.site-nav-mobile.open {
  display: flex;
}

.site-nav-mobile a {
  padding: 10px 0;
  color: var(--color-text);
  border-bottom: 1px solid var(--color-border);
}

.site-nav-mobile a:last-child {
  border-bottom: none;
}

@media (min-width: 768px) {
  .site-nav {
    display: flex;
  }
  .nav-toggle {
    display: none;
  }
  .site-nav-mobile {
    display: none !important;
  }
}

/* Breadcrumb */
.breadcrumb {
  font-size: 0.85rem;
  color: var(--color-text-muted);
  margin: 16px 0;
}

.breadcrumb a {
  color: var(--color-text-muted);
}

.breadcrumb .sep {
  margin: 0 6px;
}

/* Hero / intro */
.page-hero {
  padding: 32px 0 8px;
}

.page-hero h1 {
  font-size: 1.6rem;
  line-height: 1.35;
  margin: 0 0 14px;
}

.page-hero .intro {
  color: var(--color-text-muted);
  font-size: 1.02rem;
  max-width: 720px;
}

.warning-banner {
  background: var(--color-warning-bg);
  border: 1px solid var(--color-warning-border);
  border-radius: var(--radius);
  padding: 12px 16px;
  font-size: 0.9rem;
  margin: 16px 0;
}

/* Sections */
.page-section {
  padding: 20px 0;
  border-top: 1px solid var(--color-border);
}

.page-section:first-of-type {
  border-top: none;
}

.page-section h2 {
  font-size: 1.25rem;
  margin: 0 0 10px;
}

.page-section p {
  margin: 0 0 12px;
}

/* Table of contents */
.toc {
  background: var(--color-bg-alt);
  border-radius: var(--radius);
  padding: 16px 20px;
  margin: 20px 0;
}

.toc-title {
  font-weight: 600;
  margin-bottom: 8px;
  font-size: 0.95rem;
}

.toc ol {
  margin: 0;
  padding-left: 20px;
}

.toc li {
  margin: 4px 0;
  font-size: 0.92rem;
}

/* FAQ */
.faq-item {
  border-bottom: 1px solid var(--color-border);
}

.faq-question {
  width: 100%;
  text-align: left;
  background: none;
  border: none;
  font: inherit;
  font-weight: 600;
  padding: 14px 0;
  cursor: pointer;
  display: flex;
  justify-content: space-between;
  align-items: center;
  color: var(--color-text);
}

.faq-question .icon {
  transition: transform 0.2s ease;
  flex-shrink: 0;
  margin-left: 12px;
}

.faq-item.open .faq-question .icon {
  transform: rotate(45deg);
}

.faq-answer {
  display: none;
  padding: 0 0 14px;
  color: var(--color-text-muted);
}

.faq-item.open .faq-answer {
  display: block;
}

/* Related pages */
.related-pages {
  display: grid;
  grid-template-columns: 1fr;
  gap: 12px;
  margin: 16px 0;
}

@media (min-width: 600px) {
  .related-pages {
    grid-template-columns: repeat(2, 1fr);
  }
}

.related-card {
  border: 1px solid var(--color-border);
  border-radius: var(--radius);
  padding: 14px 16px;
  display: block;
  color: var(--color-text);
}

.related-card:hover {
  border-color: var(--color-primary);
  text-decoration: none;
}

.related-card .label {
  font-size: 0.78rem;
  color: var(--color-text-muted);
  text-transform: uppercase;
  letter-spacing: 0.02em;
}

.related-card .title {
  font-weight: 600;
  margin-top: 4px;
}

/* Comparison table */
.comparison-table-wrap {
  overflow-x: auto;
  margin: 16px 0;
}

table.comparison-table {
  width: 100%;
  border-collapse: collapse;
  font-size: 0.9rem;
}

table.comparison-table th,
table.comparison-table td {
  border: 1px solid var(--color-border);
  padding: 10px 12px;
  text-align: left;
}

table.comparison-table th {
  background: var(--color-bg-alt);
}

/* Buttons */
.btn {
  display: inline-block;
  padding: 10px 20px;
  border-radius: 8px;
  background: var(--color-primary);
  color: #fff;
  font-weight: 600;
  font-size: 0.95rem;
}

.btn:hover {
  background: var(--color-primary-dark);
  text-decoration: none;
}

/* Footer */
.site-footer {
  border-top: 1px solid var(--color-border);
  margin-top: 40px;
  padding: 24px 0 40px;
  color: var(--color-text-muted);
  font-size: 0.85rem;
}

.site-footer a {
  color: var(--color-text-muted);
}

.site-footer .disclaimer {
  margin-top: 8px;
  max-width: 720px;
}

@media (min-width: 768px) {
  .page-hero h1 {
    font-size: 2rem;
  }
  .page-section h2 {
    font-size: 1.4rem;
  }
}