:root {
  --color-bg: #ffffff;
  --color-panel: #ffffff;
  --color-text: #161514;
  --color-text-secondary: #5e5951;
  --color-text-muted: #8c857a;
  --color-border: rgba(22, 21, 20, 0.12);
  --color-grid: rgba(22, 21, 20, 0.05);
  --color-accent-101: #8b3a3a;
  --color-accent-102: #c9845a;
  --shadow-card: 0 20px 40px rgba(18, 16, 13, 0.06);
  --font-sans: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "PingFang SC", "Microsoft YaHei", sans-serif;
  --font-display: "Iowan Old Style", "Palatino Linotype", "Book Antiqua", "Songti SC", "Noto Serif SC", serif;
  --font-mono: "SF Mono", Monaco, "Cascadia Code", "Roboto Mono", Consolas, monospace;
}

* {
  margin: 0;
  padding: 0;
  box-sizing: border-box;
}

html {
  scroll-behavior: smooth;
}

body {
  font-family: var(--font-sans);
  position: relative;
  background: #ffffff;
  color: var(--color-text);
  line-height: 1.8;
  font-size: 16px;
  -webkit-font-smoothing: antialiased;
}

body::before {
  content: "";
  position: fixed;
  inset: 0;
  pointer-events: none;
  background-image:
    linear-gradient(var(--color-grid) 1px, transparent 1px),
    linear-gradient(90deg, var(--color-grid) 1px, transparent 1px);
  background-size: 32px 32px;
  mask-image: linear-gradient(to bottom, rgba(0, 0, 0, 0.42), transparent 72%);
  opacity: 0.55;
}

.nav {
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  z-index: 100;
  background: rgba(250, 250, 250, 0.95);
  backdrop-filter: blur(10px);
  border-bottom: 1px solid var(--color-border);
}

.nav-inner {
  width: 100%;
  padding: 0 clamp(20px, 2.2vw, 32px);
  height: 68px;
  display: flex;
  align-items: center;
  justify-content: space-between;
  overflow: visible;
}

.nav-logo {
  height: 78px;
  width: auto;
  display: block;
}

.nav-menu {
  display: flex;
  gap: 32px;
  list-style: none;
}

.nav-menu a {
  color: var(--color-text);
  text-decoration: none;
  font-size: 15px;
  font-weight: 600;
  transition: opacity 0.2s;
}

.nav-menu a:hover {
  opacity: 0.6;
}

.nav-toggle {
  display: none;
  background: none;
  border: none;
  cursor: pointer;
  padding: 8px;
}

.nav-toggle span {
  display: block;
  width: 24px;
  height: 2px;
  background: var(--color-text);
  margin: 5px 0;
}

.article-header {
  padding: 100px 24px 40px;
}

.article-header-inner {
  max-width: 720px;
  margin: 0 auto;
}

.article-breadcrumb {
  display: flex;
  gap: 8px;
  font-family: var(--font-mono);
  font-size: 11px;
  color: var(--color-text-muted);
  margin-bottom: 24px;
}

.article-breadcrumb a {
  color: var(--color-text-secondary);
  text-decoration: none;
}

.article-breadcrumb a:hover {
  text-decoration: underline;
}

.article-tag {
  display: inline-block;
  font-family: var(--font-mono);
  font-size: 10px;
  letter-spacing: 0.05em;
  text-transform: uppercase;
  padding: 4px 10px;
  background: var(--color-bg);
  border: 1px solid var(--color-border);
  color: var(--color-text-secondary);
  margin-bottom: 20px;
}

.article-title {
  font-size: clamp(26px, 5vw, 36px);
  font-weight: 600;
  font-family: var(--font-display);
  line-height: 1.4;
  margin-bottom: 20px;
}

.article-meta {
  display: flex;
  flex-wrap: wrap;
  gap: 16px;
  font-family: var(--font-mono);
  font-size: 12px;
  color: var(--color-text-muted);
}

.article-content {
  padding: 0 24px 60px;
}

.article-content-inner {
  max-width: 720px;
  margin: 0 auto;
}

.article-lead {
  font-size: 18px;
  color: var(--color-text-secondary);
  line-height: 1.8;
  padding-bottom: 32px;
  border-bottom: 1px solid var(--color-border);
  margin-bottom: 40px;
}

.article-summary-grid {
  display: grid;
  gap: 14px;
  margin-bottom: 40px;
}

.article-summary-card {
  padding: 20px;
  background: #ffffff;
  border: 1px solid var(--color-border);
  box-shadow: var(--shadow-card);
}

.article-summary-kicker {
  margin-bottom: 10px;
  font-family: var(--font-mono);
  font-size: 11px;
  letter-spacing: 0.12em;
  color: var(--color-text-muted);
}

.article-summary-body {
  font-size: 14px;
  line-height: 1.8;
  color: var(--color-text-secondary);
}

.article-body {
  font-size: 16px;
  line-height: 1.9;
}

.article-body h2 {
  font-size: 22px;
  font-weight: 600;
  font-family: var(--font-display);
  margin: 48px 0 20px;
  line-height: 1.4;
}

.article-body h3 {
  font-size: 18px;
  font-weight: 600;
  margin: 32px 0 16px;
}

.article-body p {
  margin-bottom: 20px;
}

.article-body ul,
.article-body ol {
  margin-bottom: 20px;
  padding-left: 24px;
}

.article-body li {
  margin-bottom: 8px;
}

.article-body strong {
  font-weight: 600;
}

.article-figure {
  margin: 32px 0;
  border: 1px solid var(--color-border);
  overflow-x: auto;
}

.article-figure img {
  max-width: 100%;
  height: auto;
  display: block;
}

.article-figure-caption {
  padding: 16px;
  font-size: 13px;
  color: var(--color-text-secondary);
  background: var(--color-bg);
  border-top: 1px solid var(--color-border);
  line-height: 1.6;
}

.article-figure-caption a {
  color: var(--color-text);
  text-decoration: underline;
  overflow-wrap: anywhere;
  word-break: break-all;
}

.highlight-box {
  padding: 24px;
  background: #ffffff;
  border-left: 4px solid var(--color-accent-101);
  box-shadow: var(--shadow-card);
  margin: 32px 0;
}

.highlight-box-title {
  font-family: var(--font-mono);
  font-size: 11px;
  letter-spacing: 0.1em;
  text-transform: uppercase;
  color: var(--color-text-muted);
  margin-bottom: 12px;
}

.highlight-box-content {
  font-size: 15px;
  color: var(--color-text-secondary);
  line-height: 1.7;
}

.references-section {
  padding: 40px 24px;
  border-top: 1px solid var(--color-border);
}

.references-section-inner {
  max-width: 720px;
  margin: 0 auto;
}

.references-title {
  font-size: 18px;
  font-weight: 600;
  font-family: var(--font-display);
  margin-bottom: 24px;
}

.references-list {
  list-style: none;
  padding: 0;
}

.references-list li {
  font-size: 14px;
  color: var(--color-text-secondary);
  line-height: 1.7;
  padding: 16px 0;
  border-bottom: 1px solid var(--color-border);
}

.references-list li:last-child {
  border-bottom: none;
}

.references-list a {
  color: var(--color-text);
  text-decoration: underline;
  overflow-wrap: anywhere;
  word-break: break-all;
}

.related-section {
  padding: 40px 24px;
  border-top: 1px solid var(--color-border);
}

.related-section-inner {
  max-width: 720px;
  margin: 0 auto;
}

.related-title {
  font-size: 18px;
  font-weight: 600;
  font-family: var(--font-display);
  margin-bottom: 24px;
}

.related-list {
  display: flex;
  flex-direction: column;
  gap: 12px;
}

.related-item {
  display: flex;
  align-items: center;
  gap: 16px;
  padding: 16px;
  background: #ffffff;
  border: 1px solid var(--color-border);
  box-shadow: var(--shadow-card);
  text-decoration: none;
  color: inherit;
  transition: all 0.2s;
}

.related-item:hover {
  border-color: var(--color-text);
}

.related-item-soon {
  background: var(--color-bg);
  color: var(--color-text-secondary);
}

.related-item-status {
  margin-left: auto;
  font-family: var(--font-mono);
  font-size: 11px;
  color: var(--color-text-muted);
  white-space: nowrap;
}

.related-item-tag {
  font-family: var(--font-mono);
  font-size: 10px;
  padding: 4px 8px;
  background: var(--color-bg);
  color: var(--color-text-muted);
  flex-shrink: 0;
}

.related-item-title {
  font-size: 14px;
  font-weight: 500;
}

.related-item-arrow {
  margin-left: auto;
  width: 16px;
  height: 16px;
  opacity: 0.4;
}

.product-links {
  padding: 40px 24px;
  border-top: 1px solid var(--color-border);
}

.product-links-inner {
  max-width: 720px;
  margin: 0 auto;
}

.product-links-title {
  font-size: 16px;
  font-weight: 600;
  font-family: var(--font-display);
  margin-bottom: 16px;
}

.product-links-list {
  display: flex;
  flex-wrap: wrap;
  gap: 12px;
}

.product-link {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  padding: 10px 20px;
  background: var(--color-text);
  color: #fff;
  text-decoration: none;
  font-size: 13px;
  font-weight: 500;
  transition: opacity 0.2s;
}

.product-link:hover {
  opacity: 0.85;
}

.footer {
  background: #1a1a1a;
  color: #fff;
  padding: 60px clamp(24px, 2.2vw, 32px) 40px;
}

.footer-inner {
  width: 100%;
}

.footer-contact {
  max-width: 360px;
  padding-bottom: 28px;
  margin-bottom: 28px;
}

.footer-contact-title {
  font-size: 18px;
  font-weight: 600;
  font-family: var(--font-display);
  color: #fff;
  margin-bottom: 14px;
}

.footer-contact-info {
  font-size: 14px;
  color: rgba(255, 255, 255, 0.72);
  line-height: 1.8;
}

.footer-bottom {
  padding-top: 32px;
  border-top: 1px solid rgba(255, 255, 255, 0.1);
  display: flex;
  flex-direction: column;
  gap: 10px;
}

.footer-disclaimer {
  font-size: 12px;
  color: rgba(255, 255, 255, 0.5);
  line-height: 1.6;
  margin: 0;
}

.footer-copyright {
  font-size: 12px;
  color: rgba(255, 255, 255, 0.5);
  line-height: 1.6;
  margin: 0;
}

@media (max-width: 768px) {
  .nav-menu {
    position: fixed;
    top: 55px;
    left: 0;
    right: 0;
    background: rgba(250, 250, 250, 0.98);
    flex-direction: column;
    padding: 24px;
    gap: 0;
    transform: translateY(-100%);
    opacity: 0;
    visibility: hidden;
    transition: all 0.3s;
    border-bottom: 1px solid var(--color-border);
  }

  .nav-menu.active {
    transform: translateY(0);
    opacity: 1;
    visibility: visible;
  }

  .nav-menu li {
    border-bottom: 1px solid var(--color-border);
  }

  .nav-menu li:last-child {
    border-bottom: none;
  }

  .nav-menu a {
    display: block;
    padding: 16px 0;
    font-size: 16px;
  }

  .nav-inner {
    height: 55px;
  }

  .nav-logo {
    height: 56px;
  }

  .nav-toggle {
    display: block;
  }

  .article-figure {
    margin-left: -24px;
    margin-right: -24px;
    border-left: none;
    border-right: none;
  }

  .highlight-box {
    margin-left: -24px;
    margin-right: -24px;
    border-left: none;
    border-left: 4px solid var(--color-accent-101);
  }

  .article-summary-grid {
    grid-template-columns: 1fr;
  }
}

@media (min-width: 769px) {
  .article-summary-grid {
    grid-template-columns: repeat(3, minmax(0, 1fr));
  }

  .footer-bottom {
    display: grid;
    grid-template-columns: minmax(0, 1fr) auto;
    gap: 32px;
    align-items: start;
  }

  .footer-copyright {
    text-align: right;
    white-space: nowrap;
  }
}