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

:root {
  --bg: #fafaf9;
  --surface: #ffffff;
  --text: #1a1a1a;
  --text-secondary: #6b7280;
  --accent: #dc2626;
  --accent-light: #fef2f2;
  --border: #e5e5e5;
  --shadow: 0 1px 3px rgba(0,0,0,0.08), 0 1px 2px rgba(0,0,0,0.06);
  --shadow-lg: 0 10px 25px rgba(0,0,0,0.08);
  --radius: 12px;
  --max-width: 800px;
}

html { scroll-behavior: smooth; }

body {
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", "Noto Sans SC", "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei", sans-serif;
  background: var(--bg);
  color: var(--text);
  line-height: 1.6;
  min-height: 100vh;
  display: flex;
  flex-direction: column;
}

.site-header {
  background: var(--surface);
  border-bottom: 1px solid var(--border);
  position: sticky;
  top: 0;
  z-index: 100;
  backdrop-filter: blur(10px);
  background: rgba(255,255,255,0.92);
}

.header-inner {
  max-width: 1100px;
  margin: 0 auto;
  padding: 0 1.25rem;
  height: 56px;
  display: flex;
  align-items: center;
  justify-content: space-between;
}

.logo {
  display: flex;
  align-items: center;
  gap: 0.5rem;
  text-decoration: none;
  color: var(--text);
  font-weight: 700;
  font-size: 1.25rem;
}

.logo-icon { font-size: 1.5rem; }

.nav { display: flex; gap: 0.25rem; }

.nav-link {
  text-decoration: none;
  color: var(--text-secondary);
  padding: 0.5rem 0.875rem;
  border-radius: 8px;
  font-size: 0.875rem;
  font-weight: 500;
  transition: all 0.15s;
}

.nav-link:hover, .nav-link.active {
  color: var(--text);
  background: var(--accent-light);
}

.nav-link.active { color: var(--accent); }

.menu-toggle {
  display: none;
  background: none;
  border: none;
  cursor: pointer;
  padding: 0.5rem;
}

.menu-toggle span {
  display: block;
  width: 20px;
  height: 2px;
  background: var(--text);
  margin: 4px 0;
  border-radius: 2px;
  transition: 0.2s;
}

.mobile-menu {
  display: none;
  background: var(--surface);
  border-bottom: 1px solid var(--border);
  padding: 0.5rem;
}

.mobile-menu.open { display: block; }

.mobile-nav-link {
  display: block;
  padding: 0.75rem 1rem;
  text-decoration: none;
  color: var(--text);
  font-weight: 500;
  border-radius: 8px;
}

.mobile-nav-link:hover { background: var(--accent-light); }

main { flex: 1; max-width: var(--max-width); margin: 0 auto; padding: 2rem 1.25rem; width: 100%; }

/* Home page */
.hero {
  text-align: center;
  padding: 2rem 0 1rem;
}

.hero h1 {
  font-size: 2.25rem;
  font-weight: 800;
  letter-spacing: -0.02em;
  margin-bottom: 0.5rem;
}

.hero p {
  color: var(--text-secondary);
  font-size: 1.05rem;
}

.notice {
  background: #fef2f2;
  border: 1px solid #fecaca;
  border-radius: 10px;
  padding: 0.75rem 1rem;
  margin: 1.5rem 0;
  font-size: 0.875rem;
  color: #991b1b;
  display: flex;
  align-items: center;
  gap: 0.5rem;
}

.section-title {
  font-size: 1.1rem;
  font-weight: 700;
  margin: 2rem 0 1rem;
  padding-bottom: 0.5rem;
  border-bottom: 2px solid var(--text);
  display: inline-block;
}

/* Article cards */
.article-list { display: flex; flex-direction: column; gap: 0.75rem; }

.article-card {
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 1.25rem;
  text-decoration: none;
  color: var(--text);
  transition: all 0.2s;
  display: flex;
  gap: 1rem;
  align-items: flex-start;
}

.article-card:hover {
  box-shadow: var(--shadow-lg);
  border-color: var(--accent);
  transform: translateY(-1px);
}

.card-icon {
  font-size: 1.75rem;
  flex-shrink: 0;
  width: 48px;
  height: 48px;
  display: flex;
  align-items: center;
  justify-content: center;
  background: var(--bg);
  border-radius: 10px;
}

.card-content { flex: 1; min-width: 0; }

.card-title {
  font-size: 1rem;
  font-weight: 600;
  line-height: 1.4;
  margin-bottom: 0.35rem;
  display: -webkit-box;
  -webkit-line-clamp: 2;
  -webkit-box-orient: vertical;
  overflow: hidden;
}

.card-meta {
  display: flex;
  align-items: center;
  gap: 0.75rem;
  font-size: 0.8rem;
  color: var(--text-secondary);
  flex-wrap: wrap;
}

.card-date { white-space: nowrap; }

.card-tags {
  display: flex;
  gap: 0.35rem;
  flex-wrap: wrap;
}

.tag {
  background: var(--bg);
  padding: 0.15rem 0.5rem;
  border-radius: 4px;
  font-size: 0.75rem;
  color: var(--text-secondary);
}

/* Article detail */
.article-detail { animation: fadeIn 0.3s ease; }

@keyframes fadeIn {
  from { opacity: 0; transform: translateY(8px); }
  to { opacity: 1; transform: translateY(0); }
}

.back-link {
  display: inline-flex;
  align-items: center;
  gap: 0.35rem;
  color: var(--text-secondary);
  text-decoration: none;
  font-size: 0.875rem;
  margin-bottom: 1.5rem;
  padding: 0.4rem 0.75rem;
  border-radius: 8px;
  transition: 0.15s;
}

.back-link:hover { background: var(--bg); color: var(--text); }

.article-header { margin-bottom: 2rem; }

.article-header h1 {
  font-size: 1.75rem;
  font-weight: 800;
  line-height: 1.3;
  letter-spacing: -0.01em;
  margin-bottom: 0.75rem;
}

.article-meta {
  display: flex;
  align-items: center;
  gap: 1rem;
  font-size: 0.875rem;
  color: var(--text-secondary);
  flex-wrap: wrap;
}

.article-body {
  font-size: 1.05rem;
  line-height: 1.8;
}

.article-body p { margin-bottom: 1.25rem; }

.article-body figure {
  margin: 1.5rem 0;
  text-align: center;
}

.article-body figure img {
  max-width: 100%;
  border-radius: 10px;
  box-shadow: var(--shadow);
}

.article-body ol, .article-body ul {
  margin: 1rem 0 1rem 1.5rem;
}

.article-body li { margin-bottom: 0.5rem; }

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

.article-body a {
  color: var(--accent);
  text-decoration: underline;
  text-underline-offset: 2px;
}

.original-link {
  display: inline-flex;
  align-items: center;
  gap: 0.35rem;
  margin-top: 2rem;
  padding: 0.6rem 1rem;
  background: var(--bg);
  border: 1px solid var(--border);
  border-radius: 8px;
  color: var(--text-secondary);
  text-decoration: none;
  font-size: 0.85rem;
  transition: 0.15s;
}

.original-link:hover {
  border-color: var(--accent);
  color: var(--accent);
}

/* About / Contact pages */
.page-content { animation: fadeIn 0.3s ease; }

.page-content h1 {
  font-size: 1.75rem;
  font-weight: 800;
  margin-bottom: 1.5rem;
}

.page-content h2 {
  font-size: 1.25rem;
  font-weight: 700;
  margin: 1.5rem 0 0.75rem;
}

.page-content p {
  margin-bottom: 1rem;
  line-height: 1.8;
  font-size: 1.05rem;
}

.page-content ol, .page-content ul {
  margin: 0.75rem 0 1rem 1.5rem;
}

.page-content li {
  margin-bottom: 0.5rem;
  line-height: 1.7;
}

.page-content a {
  color: var(--accent);
  text-decoration: underline;
  text-underline-offset: 2px;
}

/* Original viewer */
.original-viewer { animation: fadeIn 0.3s ease; }

.original-viewer h1 {
  font-size: 1.5rem;
  font-weight: 700;
  margin-bottom: 1rem;
}

.original-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(220px, 1fr));
  gap: 0.75rem;
  margin: 1.5rem 0;
}

.original-file-link {
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: 10px;
  padding: 1rem;
  text-decoration: none;
  color: var(--text);
  font-size: 0.875rem;
  transition: 0.2s;
  display: flex;
  align-items: center;
  gap: 0.5rem;
}

.original-file-link:hover {
  border-color: var(--accent);
  box-shadow: var(--shadow);
}

.original-file-link .file-icon { font-size: 1.25rem; }

.iframe-container {
  margin-top: 1.5rem;
  border: 1px solid var(--border);
  border-radius: var(--radius);
  overflow: hidden;
  background: var(--surface);
}

.iframe-container iframe {
  width: 100%;
  height: 70vh;
  border: none;
}

/* Footer */
.site-footer {
  text-align: center;
  padding: 2rem 1rem;
  color: var(--text-secondary);
  font-size: 0.85rem;
  border-top: 1px solid var(--border);
  margin-top: 3rem;
}

.footer-note { opacity: 0.6; margin-top: 0.25rem; }

/* Responsive */
@media (max-width: 640px) {
  .nav { display: none; }
  .menu-toggle { display: block; }
  .hero h1 { font-size: 1.75rem; }
  .article-header h1 { font-size: 1.4rem; }
  .article-card { padding: 1rem; }
  .card-icon { width: 40px; height: 40px; font-size: 1.4rem; }
  main { padding: 1.25rem 1rem; }
  .original-grid { grid-template-columns: 1fr; }
}