/* ============================================
   DOXA 文学院 · 视觉系统 v1
   墨色 × 朱砂 × 宣纸 —— 汉语的底色
   配合 doxa.css 品牌色
   ============================================ */

/* ---- 文学院局部 token ---- */
:root {
  --cn-ink: #2B2723;
  --cn-ink-deep: #1C1916;
  --cn-ink-soft: #EFECE6;
  --cn-cinnabar: #A63A2B;
  --cn-cinnabar-soft: #F6E7E3;
  --cn-paper: #F7F3EA;
  --cn-paper-2: #F0EBE0;
  --cn-muted: #6B6459;
  --cn-line: #E2DCCE;
  --cn-line-strong: #CEC6B4;
  --cn-surface: #FFFFFF;
  --cn-shadow-sm: 0 1px 2px rgba(28, 25, 22, 0.04), 0 1px 3px rgba(28, 25, 22, 0.06);
  --cn-shadow-md: 0 4px 16px rgba(28, 25, 22, 0.08), 0 1px 3px rgba(28, 25, 22, 0.04);
  --cn-shadow-lg: 0 12px 40px rgba(166, 58, 43, 0.12), 0 2px 8px rgba(28, 25, 22, 0.04);
  --cn-radius: 12px;
  --cn-radius-sm: 8px;
  --cn-radius-pill: 999px;
  --cn-ease: cubic-bezier(0.22, 1, 0.36, 1);
  --cn-content: 720px;
  --cn-wide: 1080px;
}

/* ---- 页面底纹：宣纸 + 极淡墨格 ---- */
body:has(.cn-hub) {
  background-color: var(--cn-paper);
  background-image:
    radial-gradient(ellipse 80% 50% at 50% -10%, rgba(166, 58, 43, 0.05), transparent 55%),
    linear-gradient(var(--cn-line) 1px, transparent 1px),
    linear-gradient(90deg, var(--cn-line) 1px, transparent 1px);
  background-size: auto, 48px 48px, 48px 48px;
  background-attachment: fixed;
}

/* ---- 导航：粘性 + 毛玻璃 ---- */
body:has(.cn-hub) .site-nav {
  position: sticky;
  top: 0;
  z-index: 100;
  backdrop-filter: blur(12px) saturate(1.2);
  -webkit-backdrop-filter: blur(12px) saturate(1.2);
  background: rgba(247, 243, 234, 0.88);
  border-bottom: 1px solid var(--cn-line);
  box-shadow: 0 1px 0 rgba(255, 255, 255, 0.6) inset;
}

body:has(.cn-hub) .nav-actions {
  flex-wrap: wrap;
  gap: 6px 14px;
  justify-content: flex-end;
}

body:has(.cn-hub) .nav-link {
  position: relative;
  font-size: 0.88rem;
  font-weight: 500;
  color: var(--cn-muted);
  text-decoration: none;
  padding: 4px 2px;
  transition: color 0.15s var(--cn-ease);
}

body:has(.cn-hub) .nav-link:hover {
  color: var(--cn-ink);
}

body:has(.cn-hub) .nav-link.is-active {
  color: var(--cn-cinnabar);
  font-weight: 600;
}

body:has(.cn-hub) .nav-link.is-active::after {
  content: "";
  position: absolute;
  left: 0;
  right: 0;
  bottom: -2px;
  height: 2px;
  background: var(--cn-cinnabar);
  border-radius: 1px;
}

/* ---- 文学院二级导航 ---- */
.cn-subnav {
  display: flex;
  align-items: center;
  gap: 4px;
  padding: 10px 24px;
  overflow-x: auto;
  background: rgba(255, 255, 255, 0.6);
  border-bottom: 1px solid var(--cn-line);
  scrollbar-width: none;
}

.cn-subnav::-webkit-scrollbar {
  display: none;
}

.cn-subnav .cs-label {
  font-family: var(--font-serif);
  font-size: 0.85rem;
  font-weight: 700;
  color: var(--cn-cinnabar);
  margin-right: 8px;
  white-space: nowrap;
}

.cn-subnav a {
  font-size: 0.88rem;
  color: var(--cn-muted);
  text-decoration: none;
  padding: 5px 12px;
  border-radius: var(--cn-radius-pill);
  white-space: nowrap;
  transition: background 0.15s, color 0.15s;
}

.cn-subnav a:hover {
  background: var(--cn-ink-soft);
  color: var(--cn-ink);
}

.cn-subnav a.is-active {
  background: var(--cn-cinnabar-soft);
  color: var(--cn-cinnabar);
  font-weight: 600;
}

body:has(.cn-hub) .container {
  max-width: var(--cn-wide);
}

/* ============================================
   文学院入口 hub（index.html）
   ============================================ */
.cn-hub-hero {
  position: relative;
  padding: 64px 24px 52px;
  text-align: center;
  overflow: hidden;
  background:
    radial-gradient(ellipse 70% 80% at 50% 0%, rgba(166, 58, 43, 0.08), transparent 60%),
    linear-gradient(180deg, var(--cn-ink-soft) 0%, var(--cn-paper) 100%);
  border-bottom: 1px solid var(--cn-line);
}

.cn-hub-hero::before {
  content: "";
  position: absolute;
  top: 0;
  left: 0;
  right: 0;
  height: 3px;
  background: linear-gradient(90deg, var(--cn-ink), var(--cn-cinnabar), #C89B3C);
}

.cn-hub-hero .hub-mark {
  width: 56px;
  height: 56px;
  margin: 0 auto 20px;
  display: flex;
  align-items: center;
  justify-content: center;
  border-radius: 16px;
  background: var(--cn-ink);
  color: #fff;
  font-family: var(--font-serif);
  font-size: 1.8rem;
  font-weight: 700;
  box-shadow: var(--cn-shadow-md);
}

.cn-hub-hero .eyebrow {
  display: inline-flex;
  font-family: var(--font-sans);
  font-size: 0.78rem;
  font-weight: 600;
  letter-spacing: 0.02em;
  color: var(--cn-cinnabar);
  margin-bottom: 14px;
  padding: 5px 14px;
  background: var(--cn-cinnabar-soft);
  border: 1px solid #E2B8AC;
  border-radius: var(--cn-radius-pill);
}

.cn-hub-hero h1 {
  font-size: clamp(2rem, 5vw, 2.75rem);
  margin-bottom: 14px;
  letter-spacing: -0.03em;
}

.cn-hub-hero .lead {
  color: var(--cn-muted);
  max-width: 560px;
  margin: 0 auto;
  font-size: 1.08rem;
  line-height: 1.7;
}

.cn-hub-hero .lead strong {
  color: var(--cn-cinnabar);
}

/* hub 卡片（与数学版面共用结构类，色值走文学院 token） */
.hub-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(260px, 1fr));
  gap: 18px;
  margin: 40px 0 48px;
}

.hub-card {
  display: flex;
  flex-direction: column;
  text-decoration: none;
  background: var(--cn-surface);
  border: 1px solid var(--cn-line);
  border-radius: var(--cn-radius);
  padding: 24px 22px;
  box-shadow: var(--cn-shadow-sm);
  transition: transform 0.2s var(--cn-ease), box-shadow 0.2s var(--cn-ease), border-color 0.2s;
  position: relative;
  overflow: hidden;
  min-height: 180px;
}

.hub-card::after {
  content: "→";
  position: absolute;
  right: 20px;
  bottom: 18px;
  font-size: 1.1rem;
  color: var(--cn-cinnabar);
  opacity: 0;
  transform: translateX(-6px);
  transition: opacity 0.2s, transform 0.2s var(--cn-ease);
}

.hub-card:hover {
  transform: translateY(-4px);
  box-shadow: var(--cn-shadow-lg);
  border-color: var(--cn-line-strong);
}

.hub-card:hover::after {
  opacity: 1;
  transform: translateX(0);
}

.hub-card .hub-icon {
  width: 40px;
  height: 40px;
  border-radius: 10px;
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 1.15rem;
  margin-bottom: 14px;
  background: var(--cn-ink-soft);
  color: var(--cn-ink);
  font-weight: 700;
  font-family: var(--font-serif);
}

.hub-card.featured .hub-icon {
  background: var(--cn-cinnabar-soft);
  color: var(--cn-cinnabar);
}

.hub-card h2 {
  font-size: 1.2rem;
  margin: 0 0 8px;
  color: var(--cn-ink);
}

.hub-card p {
  margin: 0;
  color: var(--cn-muted);
  font-size: 0.9rem;
  line-height: 1.6;
  flex: 1;
}

.hub-card .hub-meta {
  margin-top: 14px;
  font-size: 0.78rem;
  font-weight: 600;
  color: var(--cn-cinnabar);
  letter-spacing: 0.02em;
}

.hub-note {
  text-align: center;
  color: var(--cn-muted);
  font-size: 0.9rem;
  margin: 0 0 56px;
  max-width: 520px;
  margin-left: auto;
  margin-right: auto;
  line-height: 1.65;
}

/* ---- 响应式 ---- */
@media (max-width: 640px) {
  .hub-grid {
    grid-template-columns: 1fr;
    margin-top: 28px;
  }

  .cn-hub-hero {
    padding: 48px 20px 40px;
  }

  .cn-subnav {
    padding: 8px 16px;
  }
}

/* 减弱动效偏好 */
@media (prefers-reduced-motion: reduce) {
  .hub-card {
    transition: none;
  }
  .hub-card:hover {
    transform: none;
  }
}

/* ---- 单栏导航：有 cn-subnav 时隐藏站点顶栏 ---- */
body:has(.cn-subnav) .site-nav {
  display: none !important;
}
.cn-subnav {
  position: sticky;
  top: 0;
  z-index: 100;
  min-height: 48px;
  padding: 10px 20px;
  background: rgba(247, 243, 234, 0.96);
  backdrop-filter: blur(12px) saturate(1.15);
  -webkit-backdrop-filter: blur(12px) saturate(1.15);
  border-bottom: 1px solid var(--cn-line);
  box-shadow: 0 1px 0 rgba(255, 255, 255, 0.5) inset;
}
.cn-subnav .cs-brand {
  flex-shrink: 0;
  font-family: var(--font-sans);
  font-size: 0.88rem;
  font-weight: 700;
  letter-spacing: 0.12em;
  color: var(--cn-ink);
  text-decoration: none;
  padding: 4px 10px 4px 0;
  margin-right: 4px;
  border-right: 1px solid var(--cn-line);
  border-radius: 0;
  white-space: nowrap;
}
.cn-subnav .cs-brand:hover {
  background: transparent;
  color: var(--cn-cinnabar);
}