/* ================================================================
   PolaZhenjing v2 — Dark Gold Premium Design System
   Based on pola-wukong-ui (DingTalk Wukong aesthetic)
   ================================================================ */

/* ── CSS Custom Properties ──────────────────────────────────── */
:root {
  /* Background layers */
  --bg-deepest:     #050508;
  --bg-nav:         rgba(5,5,8,0.75);
  --bg-card:        rgba(255,255,255,0.06);
  --bg-card-hover:  rgba(255,255,255,0.12);
  --bg-gold-subtle: rgba(228,191,122,0.06);
  --bg-gold-light:  rgba(228,191,122,0.10);

  /* Gold palette */
  --gold-primary:   #E4BF7A;
  --gold-dark:      #D4A050;
  --gold-light:     #F0D8A8;
  --gold-pale:      #F6E8C8;
  --gold-brown:     #6B4300;
  --gold-brown-deep:#5C3800;

  /* Text hierarchy */
  --text-primary:   rgba(255,255,255,1.0);
  --text-secondary: rgba(255,255,255,0.80);
  --text-body:      rgba(255,255,255,0.65);
  --text-muted:     rgba(255,255,255,0.45);
  --text-disabled:  rgba(255,255,255,0.38);
  --text-ghost:     rgba(255,255,255,0.12);

  /* Accent */
  --accent-blue:    #4FA8FE;

  /* Gradients */
  --gradient-gold-btn: linear-gradient(135deg, #E4BF7A, #D4A050);
  --gradient-gold-badge: linear-gradient(135deg, #F6E8C8, #E4BF7A);
  --gradient-gold-card: linear-gradient(135deg, rgba(228,191,122,0.20), rgba(240,216,168,0.12));

  /* Shadows */
  --shadow-glass: inset 0 1px 0 rgba(255,255,255,0.35), 0 8px 24px rgba(228,191,122,0.16);
  --shadow-glass-hover: inset 0 1px 0 rgba(255,255,255,0.35), 0 12px 32px rgba(228,191,122,0.25);
  --shadow-badge: inset 0 1px 0 rgba(255,255,255,0.45), 0 4px 10px rgba(212,160,80,0.18);
  --shadow-btn-hover: 0 4px 16px rgba(228,191,122,0.30);
  --shadow-btn-lg-hover: 0 8px 24px rgba(228,191,122,0.35);

  /* Easing */
  --ease-primary: cubic-bezier(0.16, 1, 0.3, 1);

  /* Style accent colors */
  --style-deep-technical:    #1a1a2e;
  --style-academic-insight:  #2d6a4f;
  --style-industry-vision:   #e63946;
  --style-friendly-explainer:#f4a261;
  --style-creative-visual:   #7b2cbf;

  /* Layout */
  --container-max: 1200px;
  --nav-height: 64px;
  --radius-sm: 8px;
  --radius-md: 10px;
  --radius-lg: 16px;
  --radius-xl: 20px;
}

/* ── Reset & Base ───────────────────────────────────────────── */
*, *::before, *::after { box-sizing: border-box; margin: 0; padding: 0; }

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

body {
  font-family: -apple-system, "system-ui", "PingFang SC", "Hiragino Sans GB",
               "Microsoft YaHei", "Noto Sans CJK SC", "Source Han Sans SC",
               "Segoe UI", Roboto, "Helvetica Neue", Arial, sans-serif;
  background: var(--bg-deepest);
  color: var(--text-body);
  line-height: 1.6;
  min-height: 100vh;
}

a { color: var(--gold-primary); text-decoration: none; transition: color 0.3s; }
a:hover { color: var(--gold-light); }

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

/* ── Typography ─────────────────────────────────────────────── */
h1, h2, h3, h4, h5, h6 {
  font-family: "Source Han Serif SC", "Source Han Serif CN",
               "思源宋体 SC", "Songti SC", "STSong", serif;
  color: var(--text-primary);
  line-height: 1.2;
}

h1 { font-size: 3.5rem; font-weight: 800; }
h2 { font-size: 2.5rem; font-weight: 800; }
h3 { font-size: 1.75rem; font-weight: 700; }
h4 { font-size: 1.25rem; font-weight: 700; }

p { margin-bottom: 1em; }

code {
  font-family: "JetBrains Mono", "Fira Code", "Cascadia Code", Menlo, Consolas, monospace;
  background: var(--bg-card);
  padding: 0.15em 0.4em;
  border-radius: 4px;
  font-size: 0.9em;
  color: var(--gold-light);
}

pre {
  background: rgba(0,0,0,0.4);
  border: 1px solid var(--text-ghost);
  border-radius: var(--radius-sm);
  padding: 1.25rem;
  overflow-x: auto;
  margin: 1.5em 0;
}

pre code {
  background: none;
  padding: 0;
  color: var(--text-secondary);
}

blockquote {
  border-left: 3px solid var(--gold-primary);
  padding: 0.75em 1.25em;
  margin: 1.5em 0;
  background: var(--bg-gold-subtle);
  border-radius: 0 var(--radius-sm) var(--radius-sm) 0;
  color: var(--text-secondary);
}

table {
  width: 100%;
  border-collapse: collapse;
  margin: 1.5em 0;
}

th, td {
  padding: 0.75em 1em;
  border-bottom: 1px solid var(--text-ghost);
  text-align: left;
}

th {
  color: var(--gold-primary);
  font-weight: 600;
  font-size: 0.85em;
  text-transform: uppercase;
  letter-spacing: 0.05em;
}

hr {
  border: none;
  border-top: 1px solid var(--text-ghost);
  margin: 2.5em 0;
}

/* ── Container ──────────────────────────────────────────────── */
.container {
  max-width: var(--container-max);
  margin: 0 auto;
  padding: 0 24px;
}

/* ── Navigation ─────────────────────────────────────────────── */
.site-nav {
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  z-index: 50;
  height: var(--nav-height);
  background: var(--bg-nav);
  backdrop-filter: blur(12px);
  -webkit-backdrop-filter: blur(12px);
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 0 24px;
  border-bottom: 1px solid var(--text-ghost);
}

.nav-logo {
  font-family: "Source Han Serif SC", serif;
  font-size: 1.25rem;
  font-weight: 800;
  color: var(--text-primary);
  letter-spacing: 0.02em;
}

.nav-links {
  display: flex;
  align-items: center;
  gap: 2rem;
  list-style: none;
}

.nav-links a {
  color: var(--text-secondary);
  font-size: 0.95rem;
  transition: color 0.3s;
}

.nav-links a:hover { color: var(--gold-primary); }

/* ── Buttons ────────────────────────────────────────────────── */
.btn-gold {
  display: inline-block;
  background: var(--gradient-gold-btn);
  color: var(--gold-brown);
  font-weight: 600;
  font-size: 0.85rem;
  padding: 0.5rem 1.125rem;
  border-radius: var(--radius-md);
  border: none;
  cursor: pointer;
  transition: all 0.3s var(--ease-primary);
  text-decoration: none;
}

.btn-gold:hover {
  box-shadow: var(--shadow-btn-hover);
  transform: translateY(-2px);
  color: var(--gold-brown-deep);
}

.btn-gold-lg {
  font-size: 1rem;
  padding: 1rem 2.25rem;
  border-radius: var(--radius-lg);
}

.btn-gold-lg:hover {
  box-shadow: var(--shadow-btn-lg-hover);
  transform: translateY(-4px);
}

.btn-ghost {
  display: inline-block;
  color: var(--text-muted);
  font-size: 0.85rem;
  padding: 0.5rem 1rem;
  border: 1px solid var(--text-ghost);
  border-radius: var(--radius-sm);
  background: transparent;
  cursor: pointer;
  transition: all 0.3s;
  text-decoration: none;
}

.btn-ghost:hover {
  color: var(--gold-primary);
  border-color: rgba(228,191,122,0.3);
  background: var(--bg-gold-subtle);
}

.btn-danger {
  display: inline-block;
  color: #e63946;
  font-size: 0.85rem;
  padding: 0.5rem 1rem;
  border: 1px solid rgba(230,57,70,0.3);
  border-radius: var(--radius-sm);
  background: transparent;
  cursor: pointer;
  transition: all 0.3s;
}

.btn-danger:hover {
  background: rgba(230,57,70,0.1);
  border-color: #e63946;
}

/* ── Hero ───────────────────────────────────────────────────── */
.hero {
  position: relative;
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  min-height: 50vh;
  padding: calc(var(--nav-height) + 4rem) 24px 4rem;
  text-align: center;
  overflow: hidden;
}

.hero-glow {
  position: absolute;
  inset: 0;
  background: radial-gradient(circle at 50% 40%, rgba(228,191,122,0.08) 0%, transparent 70%);
  pointer-events: none;
}

.hero-content {
  position: relative;
  z-index: 1;
}

.hero-title {
  font-size: 4.5rem;
  font-weight: 800;
  background: var(--gradient-gold-btn);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
}

.hero-subtitle {
  margin-top: 1rem;
  font-size: 1.2rem;
  color: var(--text-body);
  max-width: 600px;
  margin-left: auto;
  margin-right: auto;
}

/* ── Section ────────────────────────────────────────────────── */
.section-title {
  text-align: center;
  margin-bottom: 3rem;
  font-size: 2rem;
}

.articles-section {
  padding: 4rem 0 6rem;
}

/* ── Article Grid ───────────────────────────────────────────── */
.article-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(340px, 1fr));
  gap: 1.5rem;
}

.article-card {
  border: 1px solid rgba(212,160,80,0.2);
  background: var(--gradient-gold-card);
  border-radius: var(--radius-xl);
  overflow: hidden;
  transition: all 0.3s var(--ease-primary);
}

.article-card:hover {
  transform: translateY(-4px);
  box-shadow: var(--shadow-glass-hover);
  border-color: rgba(212,160,80,0.4);
}

.article-card-inner {
  padding: 1.5rem;
}

.article-title {
  font-size: 1.25rem;
  margin: 0.75rem 0 0.5rem;
}

.article-title a {
  color: var(--text-primary);
  transition: color 0.3s;
}

.article-title a:hover { color: var(--gold-primary); }

.article-date {
  font-size: 0.8rem;
  color: var(--text-muted);
}

.article-desc {
  margin: 0.75rem 0;
  font-size: 0.9rem;
  color: var(--text-body);
  line-height: 1.6;
}

.article-tags {
  display: flex;
  flex-wrap: wrap;
  gap: 0.5rem;
  margin-top: 0.75rem;
}

.tag {
  display: inline-block;
  font-size: 0.7rem;
  font-weight: 600;
  padding: 0.2em 0.6em;
  border-radius: 6px;
  background: var(--bg-card);
  color: var(--text-muted);
  border: 1px solid var(--text-ghost);
}

/* ── Style Badges ───────────────────────────────────────────── */
.style-badge {
  display: inline-block;
  font-size: 0.625rem;
  font-weight: 600;
  padding: 0.2em 0.6em;
  border-radius: 6px;
  text-transform: capitalize;
  letter-spacing: 0.03em;
}

.style-deep-technical     { background: #1a1a2e; color: #8b9dc3; border: 1px solid rgba(139,157,195,0.3); }
.style-academic-insight   { background: rgba(45,106,79,0.2); color: #52b788; border: 1px solid rgba(82,183,136,0.3); }
.style-industry-vision    { background: rgba(230,57,70,0.15); color: #ff6b6b; border: 1px solid rgba(255,107,107,0.3); }
.style-friendly-explainer { background: rgba(244,162,97,0.15); color: #f4a261; border: 1px solid rgba(244,162,97,0.3); }
.style-creative-visual    { background: rgba(123,44,191,0.15); color: #b68efc; border: 1px solid rgba(182,142,252,0.3); }

/* ── Pagination ─────────────────────────────────────────────── */
.pagination {
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 1.5rem;
  margin-top: 3rem;
}

.page-info {
  color: var(--text-muted);
  font-size: 0.85rem;
}

/* ── Post Content ───────────────────────────────────────────── */
.post-header {
  padding: calc(var(--nav-height) + 3rem) 0 2rem;
  text-align: center;
}

.post-meta {
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 1rem;
  margin-top: 1rem;
  color: var(--text-muted);
  font-size: 0.85rem;
}

.post-content {
  max-width: 780px;
  margin: 0 auto;
  padding: 2rem 24px 4rem;
  font-size: 1.05rem;
  line-height: 1.8;
  color: var(--text-secondary);
}

.post-content h1 { font-size: 2.25rem; margin: 2.5em 0 0.75em; }
.post-content h2 { font-size: 1.75rem; margin: 2em 0 0.75em; border-bottom: 1px solid var(--text-ghost); padding-bottom: 0.5em; }
.post-content h3 { font-size: 1.35rem; margin: 1.75em 0 0.5em; }
.post-content h4 { font-size: 1.1rem; margin: 1.5em 0 0.5em; }

.post-content img {
  border-radius: var(--radius-sm);
  margin: 1.5em 0;
  box-shadow: 0 4px 16px rgba(0,0,0,0.3);
}

.post-content ul, .post-content ol {
  padding-left: 1.5em;
  margin: 1em 0;
}

.post-content li { margin: 0.4em 0; }

/* ── Footer ─────────────────────────────────────────────────── */
.site-footer {
  border-top: 1px solid var(--text-ghost);
  padding: 2rem 24px;
}

.footer-inner {
  max-width: var(--container-max);
  margin: 0 auto;
  display: flex;
  align-items: center;
  justify-content: space-between;
  color: var(--text-muted);
  font-size: 0.8rem;
}

.footer-links {
  display: flex;
  gap: 1rem;
}

.footer-links a {
  color: var(--text-disabled);
  font-size: 0.75rem;
  transition: color 0.3s;
}

.footer-links a:hover { color: var(--text-body); }

/* ── Empty State ────────────────────────────────────────────── */
.empty-state {
  text-align: center;
  padding: 4rem 2rem;
  color: var(--text-muted);
  border: 1px dashed var(--text-ghost);
  border-radius: var(--radius-xl);
}

/* ── Responsive ─────────────────────────────────────────────── */
@media (max-width: 768px) {
  .hero-title { font-size: 2.5rem; }
  .hero-subtitle { font-size: 1rem; }
  .article-grid { grid-template-columns: 1fr; }
  .nav-links { display: none; }
  .section-title { font-size: 1.5rem; }
  .post-content { font-size: 1rem; }
}