:root {
  --color-bg: #f5f7fa;
  --color-surface: #ffffff;
  --color-text: #1a1a2e;
  --color-text-muted: #5c6370;
  --color-accent: #1e88a8;
  --color-accent-dark: #15657e;
  --color-accent-light: #e8f4f8;
  --color-accent-gradient: linear-gradient(135deg, #1e88a8, #0d47a1);
  --color-border: #e2e8f0;
  --color-shadow: rgba(30, 136, 168, 0.08);
  --font-serif: "LXGW WenKai", "Noto Serif SC", "Source Han Serif SC", "Songti SC", serif;
  --font-sans: "PingFang SC", "Microsoft YaHei", "Helvetica Neue", sans-serif;
  --max-width: 680px;
  --container-width: 960px;
  --radius-sm: 0.375rem;
  --radius-md: 0.75rem;
  --radius-lg: 1rem;
  --transition: 0.3s cubic-bezier(0.4, 0, 0.2, 1);
}

*,
*::before,
*::after {
  box-sizing: border-box;
}

html {
  font-size: 16px;
  scroll-behavior: smooth;
}

body {
  margin: 0;
  font-family: var(--font-serif);
  color: var(--color-text);
  background: var(--color-bg);
  line-height: 1.8;
  min-height: 100vh;
  display: flex;
  flex-direction: column;
}

::selection {
  background: var(--color-accent);
  color: #fff;
}

.container {
  width: 100%;
  max-width: var(--container-width);
  margin: 0 auto;
  padding: 0 1.25rem;
}

.main {
  flex: 1;
}

/* ===== Header ===== */
.site-header {
  background: rgba(255, 255, 255, 0.92);
  backdrop-filter: blur(12px);
  -webkit-backdrop-filter: blur(12px);
  border-bottom: 1px solid var(--color-border);
  position: sticky;
  top: 0;
  z-index: 100;
}

.header-inner {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 0.75rem 1.25rem;
  gap: 1rem;
}

.site-brand {
  text-decoration: none;
  color: var(--color-text);
  display: flex;
  align-items: baseline;
  gap: 0.5rem;
  flex-shrink: 0;
}

.site-name {
  font-size: 1.5rem;
  font-weight: 700;
  background: var(--color-accent-gradient);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
}

.site-name-en {
  font-family: var(--font-sans);
  font-size: 0.875rem;
  color: var(--color-text-muted);
  letter-spacing: 0.05em;
}

.site-nav {
  display: flex;
  gap: 0.25rem;
  flex-wrap: wrap;
  align-items: center;
}

.nav-link {
  font-family: var(--font-sans);
  font-size: 0.9375rem;
  text-decoration: none;
  color: var(--color-text-muted);
  padding: 0.375rem 0.75rem;
  border-radius: var(--radius-sm);
  transition: color var(--transition), background var(--transition);
  position: relative;
}

.nav-link::after {
  content: '';
  position: absolute;
  bottom: 0;
  left: 50%;
  transform: translateX(-50%) scaleX(0);
  width: 60%;
  height: 2px;
  background: var(--color-accent);
  transition: transform var(--transition);
  border-radius: 1px;
}

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

.nav-link:hover::after,
.nav-link.active::after {
  transform: translateX(-50%) scaleX(1);
}

/* ===== Hero ===== */
.hero {
  text-align: center;
  padding: 5rem 1.25rem 3.5rem;
  background: linear-gradient(180deg, var(--color-accent-light) 0%, var(--color-bg) 100%);
  position: relative;
  overflow: hidden;
}

.hero::before {
  content: '';
  position: absolute;
  top: -50%;
  left: -50%;
  width: 200%;
  height: 200%;
  background: radial-gradient(circle at 30% 40%, rgba(30, 136, 168, 0.06) 0%, transparent 50%),
              radial-gradient(circle at 70% 60%, rgba(13, 71, 161, 0.04) 0%, transparent 50%);
  pointer-events: none;
}

.hero-title {
  font-size: 3.5rem;
  font-weight: 700;
  margin: 0;
  background: var(--color-accent-gradient);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
  letter-spacing: 0.1em;
  position: relative;
}

.hero-subtitle {
  font-family: var(--font-sans);
  font-size: 1rem;
  color: var(--color-text-muted);
  letter-spacing: 0.2em;
  margin: 0.25rem 0 1.5rem;
  text-transform: uppercase;
}

.hero-slogan {
  font-size: 1.25rem;
  color: var(--color-text);
  margin: 0 0 1rem;
  position: relative;
}

.hero-intro {
  max-width: 36rem;
  margin: 0 auto;
  color: var(--color-text-muted);
  font-size: 1rem;
  position: relative;
}

/* ===== Home Sections ===== */
.home-sections {
  padding: 2rem 0 4rem;
}

.section-block {
  margin-bottom: 3rem;
  animation: fadeInUp 0.5s ease both;
}

.section-block:nth-child(1) { animation-delay: 0.1s; }
.section-block:nth-child(2) { animation-delay: 0.2s; }
.section-block:nth-child(3) { animation-delay: 0.3s; }

.section-header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  margin-bottom: 1.25rem;
  padding-bottom: 0.75rem;
  border-bottom: 2px solid var(--color-accent);
}

.section-title {
  font-size: 1.5rem;
  margin: 0;
  color: var(--color-text);
}

.section-more {
  font-family: var(--font-sans);
  font-size: 0.875rem;
  color: var(--color-accent);
  text-decoration: none;
  transition: color var(--transition);
  display: inline-flex;
  align-items: center;
  gap: 0.25rem;
}

.section-more:hover {
  color: var(--color-accent-dark);
  text-decoration: underline;
}

/* ===== Article List ===== */
.article-list {
  list-style: none;
  padding: 0;
  margin: 0;
}

.article-item {
  margin-bottom: 0.75rem;
}

.article-link {
  display: block;
  padding: 1.25rem 1.5rem;
  background: var(--color-surface);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-md);
  text-decoration: none;
  color: inherit;
  transition: border-color var(--transition), box-shadow var(--transition), transform var(--transition);
}

.article-link:hover {
  border-color: var(--color-accent);
  box-shadow: 0 4px 16px var(--color-shadow);
  transform: translateY(-2px);
}

.article-title {
  font-size: 1.125rem;
  margin: 0 0 0.5rem;
  color: var(--color-text);
  transition: color var(--transition);
}

.article-link:hover .article-title {
  color: var(--color-accent);
}

.article-meta {
  font-family: var(--font-sans);
  font-size: 0.8125rem;
  color: var(--color-text-muted);
  display: flex;
  gap: 1rem;
}

.article-desc {
  font-size: 0.9375rem;
  color: var(--color-text-muted);
  margin: 0.5rem 0 0;
  line-height: 1.6;
}

/* ===== Page Header ===== */
.page-header {
  padding: 3rem 1.25rem 2rem;
  text-align: center;
  background: linear-gradient(180deg, var(--color-accent-light) 0%, var(--color-bg) 100%);
  position: relative;
  overflow: hidden;
}

.page-header::before {
  content: '';
  position: absolute;
  top: -50%;
  left: -50%;
  width: 200%;
  height: 200%;
  background: radial-gradient(circle at 50% 30%, rgba(30, 136, 168, 0.05) 0%, transparent 50%);
  pointer-events: none;
}

.page-title {
  font-size: 2rem;
  margin: 0 0 0.75rem;
  color: var(--color-accent);
  position: relative;
}

.page-intro {
  max-width: 36rem;
  margin: 0 auto;
  color: var(--color-text-muted);
  position: relative;
}

.list-section {
  padding: 2rem 0 4rem;
}

.empty-state {
  text-align: center;
  color: var(--color-text-muted);
  padding: 3rem;
}

/* ===== Article Page ===== */
.article-page {
  padding: 3rem 0 4rem;
}

.article-header {
  max-width: var(--max-width);
  margin: 0 auto 2.5rem;
  text-align: center;
}

.article-page-title {
  font-size: 2rem;
  margin: 0 0 1rem;
  line-height: 1.4;
}

.article-content {
  max-width: var(--max-width);
  margin: 0 auto;
  font-size: 1.0625rem;
}

.article-content p {
  margin: 0 0 1.25rem;
}

.article-content h2,
.article-content h3 {
  margin: 2rem 0 1rem;
  color: var(--color-text);
}

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

.article-content a:hover {
  color: var(--color-accent-dark);
}

.article-content blockquote {
  margin: 1.5rem 0;
  padding: 0.75rem 1.25rem;
  border-left: 3px solid var(--color-accent);
  background: var(--color-accent-light);
  color: var(--color-text-muted);
  border-radius: 0 var(--radius-sm) var(--radius-sm) 0;
}

.article-content img {
  max-width: 100%;
  height: auto;
  border-radius: var(--radius-md);
  margin: 1.5rem auto;
  display: block;
  box-shadow: 0 2px 12px rgba(0, 0, 0, 0.08);
}

.article-content pre {
  background: #1a1a2e;
  color: #e2e8f0;
  padding: 1.25rem;
  border-radius: var(--radius-md);
  overflow-x: auto;
  font-size: 0.875rem;
  line-height: 1.6;
  margin: 1.5rem 0;
}

.article-content code {
  font-family: "JetBrains Mono", "Fira Code", monospace;
  font-size: 0.875em;
}

.article-content :not(pre) > code {
  background: var(--color-accent-light);
  color: var(--color-accent-dark);
  padding: 0.125rem 0.375rem;
  border-radius: 0.25rem;
}

/* Poetry styling */
.article-poetry .article-content {
  text-align: center;
  line-height: 2.2;
  white-space: pre-line;
}

.article-poetry .article-content p {
  margin-bottom: 0.5rem;
}

.article-footer {
  max-width: var(--max-width);
  margin: 3rem auto 0;
  padding-top: 2rem;
  border-top: 1px solid var(--color-border);
}

.back-link {
  font-family: var(--font-sans);
  font-size: 0.9375rem;
  color: var(--color-accent);
  text-decoration: none;
  transition: color var(--transition);
  display: inline-flex;
  align-items: center;
  gap: 0.25rem;
}

.back-link:hover {
  color: var(--color-accent-dark);
  text-decoration: underline;
}

/* ===== Footer ===== */
.site-footer {
  background: var(--color-surface);
  border-top: 1px solid var(--color-border);
  padding: 2.5rem 1.25rem;
  text-align: center;
}

.footer-slogan {
  font-size: 1rem;
  color: var(--color-accent);
  margin: 0 0 0.5rem;
}

.footer-copy {
  font-family: var(--font-sans);
  font-size: 0.8125rem;
  color: var(--color-text-muted);
  margin: 0;
}

.footer-author {
  color: var(--color-accent);
  text-decoration: none;
  font-weight: 500;
  transition: color var(--transition);
}

.footer-author:hover {
  color: var(--color-accent-dark);
  text-decoration: underline;
}

/* ===== Animations ===== */
@keyframes fadeIn {
  from { opacity: 0; }
  to { opacity: 1; }
}

@keyframes slideDown {
  from {
    opacity: 0;
    transform: translateY(-12px) scale(0.98);
  }
  to {
    opacity: 1;
    transform: translateY(0) scale(1);
  }
}

@keyframes fadeInUp {
  from {
    opacity: 0;
    transform: translateY(20px);
  }
  to {
    opacity: 1;
    transform: translateY(0);
  }
}

/* ===== Responsive ===== */
@media (max-width: 640px) {
  .header-inner {
    flex-direction: column;
    align-items: flex-start;
  }

  .site-nav {
    width: 100%;
  }

  .hero-title {
    font-size: 2.5rem;
  }

  .hero {
    padding: 3rem 1.25rem 2.5rem;
  }

  .hero-slogan {
    font-size: 1.0625rem;
  }

  .section-header {
    flex-direction: column;
    align-items: flex-start;
    gap: 0.5rem;
  }

  .article-page-title {
    font-size: 1.625rem;
  }


}