/* ==========================================================================
   Oxford Child Theme - 主样式表
   ========================================================================== */


/* ==========================================================================
   1. 设计 Tokens（CSS 变量）
   ========================================================================== */
:root {
  /* ----- 主色系（Oxford Blue 官方品牌色）----- */
  --ct-color-primary: #002147;        /* Oxford Blue - University of Oxford 官方主色 */
  --ct-color-primary-hover: #1e3a6f;
  --ct-color-primary-light: #e6ebf2;

  /* ----- 强调色（Oxford 辅助色系）----- */
  --ct-color-accent: #cf7a30;         /* Oxford 温暖琥珀色 */
  --ct-color-accent-hover: #e08d43;

  /* ----- 中性色 ----- */
  --ct-color-text: #1a1a1a;
  --ct-color-text-muted: #595959;
  --ct-color-text-light: #8a8a8a;
  --ct-color-heading: #002147;        /* 标题也用牛津蓝 */

  /* ----- 背景 ----- */
  --ct-color-bg: #ffffff;
  --ct-color-bg-alt: #f5f5f0;         /* Oxford Stone - 米色背景 */
  --ct-color-bg-dark: #002147;

  /* ----- 边框 ----- */
  --ct-color-border: #e5e5e0;
  --ct-color-border-dark: #c8c8c0;

  /* ----- 字体 ----- */
  --ct-font-heading: 'Source Serif Pro', 'Charter', Georgia, serif;
  --ct-font-body: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', sans-serif;

  /* ----- 字号 ----- */
  --ct-fs-h1: clamp(2rem, 4vw, 3rem);
  --ct-fs-h2: clamp(1.5rem, 3vw, 2.25rem);
  --ct-fs-h3: clamp(1.25rem, 2vw, 1.5rem);
  --ct-fs-h4: 1.125rem;
  --ct-fs-body: 1rem;
  --ct-fs-small: 0.875rem;
  --ct-fs-xs: 0.75rem;

  /* ----- 行高 ----- */
  --ct-lh-tight: 1.2;
  --ct-lh-normal: 1.6;
  --ct-lh-loose: 1.8;

  /* ----- 间距 ----- */
  --ct-space-xs: 0.5rem;
  --ct-space-sm: 1rem;
  --ct-space-md: 1.5rem;
  --ct-space-lg: 2.5rem;
  --ct-space-xl: 4rem;
  --ct-space-2xl: 6rem;

  /* ----- 容器 ----- */
  --ct-container-max: 1200px;
  --ct-container-narrow: 860px;

  /* ----- 圆角 ----- */
  --ct-radius-sm: 2px;
  --ct-radius-md: 4px;
  --ct-radius-lg: 8px;

  /* ----- 阴影 ----- */
  --ct-shadow-sm: 0 1px 3px rgba(0, 0, 0, 0.06);
  --ct-shadow-md: 0 4px 12px rgba(0, 0, 0, 0.08);
  --ct-shadow-lg: 0 8px 24px rgba(0, 0, 0, 0.10);

  /* ----- 过渡 ----- */
  --ct-transition: 0.25s ease;
}


/* ==========================================================================
   2. 全局基础
   ========================================================================== */
body.oxford-theme {
  font-family: var(--ct-font-body);
  font-size: var(--ct-fs-body);
  line-height: var(--ct-lh-normal);
  color: var(--ct-color-text);
  background: var(--ct-color-bg);
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
}


/* ==========================================================================
   3. 标题
   ========================================================================== */
.oxford-theme h1,
.oxford-theme h2,
.oxford-theme h3,
.oxford-theme h4,
.oxford-theme h5,
.oxford-theme h6,
.oxford-theme .entry-title,
.oxford-theme .page-title {
  font-family: var(--ct-font-heading);
  color: var(--ct-color-heading);
  line-height: var(--ct-lh-tight);
  font-weight: 700;
  letter-spacing: -0.01em;
  margin-top: 0;
  margin-bottom: var(--ct-space-sm);
}

.oxford-theme h1 { font-size: var(--ct-fs-h1); }
.oxford-theme h2 { font-size: var(--ct-fs-h2); }
.oxford-theme h3 { font-size: var(--ct-fs-h3); }
.oxford-theme h4 { font-size: var(--ct-fs-h4); }

.section-heading::after {
  content: '';
  display: block;
  width: 3rem;
  height: 3px;
  background: var(--ct-color-accent);
  margin-top: var(--ct-space-sm);
}


/* ==========================================================================
   4. 链接
   ========================================================================== */
.oxford-theme a {
  color: var(--ct-color-primary);
  text-decoration: underline;
  text-decoration-thickness: 1px;
  text-underline-offset: 2px;
  transition: color var(--ct-transition);
}

.oxford-theme a:hover {
  color: var(--ct-color-accent);
  text-decoration-thickness: 2px;
}

.oxford-theme nav a,
.oxford-theme .ct-header a,
.oxford-theme .ct-footer a,
.oxford-theme .academic-card a {
  text-decoration: none;
}


/* ==========================================================================
   5. Header / 导航
   ========================================================================== */
.oxford-theme [data-row="top"] {
  background: var(--ct-color-bg-alt);
  border-bottom: 1px solid var(--ct-color-border);
  font-size: var(--ct-fs-small);
}

.oxford-theme [data-row="middle"] {
  background: var(--ct-color-bg);
  border-bottom: 2px solid var(--ct-color-primary);
}

.oxford-theme .ct-main-navigation > ul > li > a {
  font-family: var(--ct-font-body);
  font-size: var(--ct-fs-body);
  font-weight: 500;
  letter-spacing: 0.02em;
  padding: 0 var(--ct-space-sm);
  color: var(--ct-color-heading);
  transition: color var(--ct-transition);
}

.oxford-theme .ct-main-navigation > ul > li > a:hover,
.oxford-theme .ct-main-navigation > ul > li.current-menu-item > a {
  color: var(--ct-color-accent);
}

.oxford-theme .ct-main-navigation .sub-menu {
  background: var(--ct-color-bg);
  border-top: 3px solid var(--ct-color-accent);
  box-shadow: var(--ct-shadow-md);
  border-radius: 0;
  padding: var(--ct-space-xs) 0;
}

.oxford-theme .ct-main-navigation .sub-menu a {
  padding: var(--ct-space-xs) var(--ct-space-md);
  font-size: var(--ct-fs-small);
  color: var(--ct-color-text);
  border-left: 3px solid transparent;
  transition: all var(--ct-transition);
}

.oxford-theme .ct-main-navigation .sub-menu a:hover {
  background: var(--ct-color-primary-light);
  border-left-color: var(--ct-color-accent);
  color: var(--ct-color-primary);
}


/* ==========================================================================
   6. Hero 区块
   ========================================================================== */
.hero-section {
  position: relative;
  min-height: 60vh;
  display: flex;
  align-items: flex-end;
  padding: var(--ct-space-2xl) 0 var(--ct-space-xl);
  background-size: cover;
  background-position: center;
  color: #fff;
}

.hero-section::before {
  content: '';
  position: absolute;
  inset: 0;
  background: linear-gradient(to bottom, rgba(0, 33, 71, 0.2) 0%, rgba(0, 33, 71, 0.75) 100%);
}

.hero-section > * {
  position: relative;
  z-index: 1;
}

.hero-section h1 {
  color: #fff;
  max-width: 800px;
}


/* ==========================================================================
   7. 区块通用
   ========================================================================== */
.section-padding {
  padding: var(--ct-space-2xl) 0;
}

.section-alt {
  background: var(--ct-color-bg-alt);
}

.section-header {
  margin-bottom: var(--ct-space-xl);
  max-width: 720px;
}

.section-eyebrow {
  display: inline-block;
  font-family: var(--ct-font-body);
  font-size: var(--ct-fs-xs);
  font-weight: 600;
  letter-spacing: 0.15em;
  text-transform: uppercase;
  color: var(--ct-color-accent);
  margin-bottom: var(--ct-space-xs);
}


/* ==========================================================================
   8. 学术卡片
   ========================================================================== */
.academic-card {
  background: var(--ct-color-bg);
  border: 1px solid var(--ct-color-border);
  border-radius: var(--ct-radius-md);
  overflow: hidden;
  transition: transform var(--ct-transition), box-shadow var(--ct-transition);
  display: flex;
  flex-direction: column;
  height: 100%;
  position: relative;
}

.academic-card:hover {
  transform: translateY(-4px);
  box-shadow: var(--ct-shadow-lg);
}

.academic-card__image {
  aspect-ratio: 16 / 10;
  overflow: hidden;
  background: var(--ct-color-bg-alt);
}

.academic-card__image img {
  width: 100%;
  height: 100%;
  object-fit: cover;
  transition: transform 0.4s ease;
}

.academic-card:hover .academic-card__image img {
  transform: scale(1.05);
}

.academic-card__body {
  padding: var(--ct-space-md);
  flex: 1;
  display: flex;
  flex-direction: column;
}

.academic-card__meta {
  font-size: var(--ct-fs-xs);
  text-transform: uppercase;
  letter-spacing: 0.1em;
  color: var(--ct-color-text-light);
  margin-bottom: var(--ct-space-xs);
}

.academic-card__title {
  font-size: var(--ct-fs-h4);
  margin-bottom: var(--ct-space-xs);
  line-height: var(--ct-lh-tight);
}

.academic-card__title a {
  color: var(--ct-color-heading);
}

.academic-card__title a:hover {
  color: var(--ct-color-accent);
}

.academic-card__excerpt {
  font-size: var(--ct-fs-small);
  color: var(--ct-color-text-muted);
  margin-bottom: var(--ct-space-sm);
}

.academic-card__date-badge {
  position: absolute;
  top: var(--ct-space-sm);
  left: var(--ct-space-sm);
  background: var(--ct-color-primary);
  color: #fff;
  padding: var(--ct-space-xs) var(--ct-space-sm);
  text-align: center;
  font-family: var(--ct-font-heading);
  z-index: 2;
}

.academic-card__date-badge .day {
  display: block;
  font-size: 1.5rem;
  font-weight: 700;
  line-height: 1;
}

.academic-card__date-badge .month {
  display: block;
  font-size: var(--ct-fs-xs);
  text-transform: uppercase;
  letter-spacing: 0.1em;
}


/* ==========================================================================
   9. 按钮
   ========================================================================== */
.oxford-theme .wp-block-button__link,
.ct-button,
.oxford-theme button.button {
  font-family: var(--ct-font-body);
  font-size: var(--ct-fs-small);
  font-weight: 600;
  letter-spacing: 0.02em;
  padding: 0.75rem 1.75rem;
  border-radius: var(--ct-radius-md);
  text-decoration: none;
  display: inline-block;
  transition: all var(--ct-transition);
  border: 2px solid transparent;
  cursor: pointer;
  background: var(--ct-color-primary);
  color: #fff;
}

.oxford-theme .wp-block-button__link:hover,
.ct-button--primary:hover {
  background: var(--ct-color-primary-hover);
  color: #fff;
  transform: translateY(-1px);
}

.ct-button--outline,
.oxford-theme .is-style-outline .wp-block-button__link {
  background: transparent;
  color: var(--ct-color-primary);
  border-color: var(--ct-color-primary);
}

.ct-button--outline:hover,
.oxford-theme .is-style-outline .wp-block-button__link:hover {
  background: var(--ct-color-primary);
  color: #fff;
}

.ct-button--link {
  background: none;
  color: var(--ct-color-primary);
  padding: 0;
  font-weight: 600;
  border: none;
}

.ct-button--link::after {
  content: ' →';
  transition: transform var(--ct-transition);
  display: inline-block;
}

.ct-button--link:hover::after {
  transform: translateX(4px);
}


/* ==========================================================================
   10. Swiper / Carousel
   ========================================================================== */
.swiper-button-next,
.swiper-button-prev {
  width: 44px;
  height: 44px;
  background: var(--ct-color-primary);
  border-radius: 50%;
  color: #fff;
}

.swiper-button-next::after,
.swiper-button-prev::after {
  font-size: 18px;
  font-weight: 700;
}

.swiper-pagination-bullet {
  background: var(--ct-color-border-dark);
  opacity: 1;
}

.swiper-pagination-bullet-active {
  background: var(--ct-color-accent);
}

.carousel-pause-btn {
  display: inline-flex;
  align-items: center;
  gap: 0.5rem;
  font-size: var(--ct-fs-small);
  padding: 0.5rem 1rem;
  background: transparent;
  border: 1px solid var(--ct-color-border);
  border-radius: var(--ct-radius-md);
  cursor: pointer;
  margin-top: var(--ct-space-sm);
}

.carousel-pause-btn[aria-pressed="true"] {
  background: var(--ct-color-primary);
  color: #fff;
  border-color: var(--ct-color-primary);
}


/* ==========================================================================
   11. 文章内容页
   ========================================================================== */
.oxford-article .entry-content {
  font-size: 1.0625rem;
  line-height: var(--ct-lh-loose);
  max-width: var(--ct-container-narrow);
  margin: 0 auto;
}

.oxford-article .entry-content h2,
.oxford-article .entry-content h3 {
  margin-top: var(--ct-space-lg);
}

.oxford-article .entry-content blockquote {
  border-left: 4px solid var(--ct-color-accent);
  padding: var(--ct-space-sm) var(--ct-space-md);
  margin: var(--ct-space-md) 0;
  font-style: italic;
  color: var(--ct-color-text-muted);
  background: var(--ct-color-bg-alt);
}

.oxford-article .entry-content img {
  border-radius: var(--ct-radius-md);
}

.oxford-article .entry-content figcaption {
  font-size: var(--ct-fs-small);
  color: var(--ct-color-text-light);
  text-align: center;
  margin-top: var(--ct-space-xs);
}


/* ==========================================================================
   12. Footer
   ========================================================================== */
.oxford-theme .ct-footer {
  background: var(--ct-color-bg-dark);
  color: rgba(255, 255, 255, 0.85);
  font-size: var(--ct-fs-small);
}

.oxford-theme .ct-footer h3,
.oxford-theme .ct-footer h4 {
  color: #fff;
  font-size: var(--ct-fs-body);
  margin-bottom: var(--ct-space-sm);
  padding-bottom: var(--ct-space-xs);
  border-bottom: 1px solid rgba(255, 255, 255, 0.2);
}

.oxford-theme .ct-footer a {
  color: rgba(255, 255, 255, 0.85);
}

.oxford-theme .ct-footer a:hover {
  color: var(--ct-color-accent-hover);
}

.oxford-theme .ct-footer ul {
  list-style: none;
  padding: 0;
}

.oxford-theme .ct-footer li {
  margin-bottom: var(--ct-space-xs);
}


/* ==========================================================================
   13. 无障碍
   ========================================================================== */
.skip-link {
  position: absolute;
  top: -40px;
  left: 0;
  background: var(--ct-color-primary);
  color: #fff;
  padding: var(--ct-space-xs) var(--ct-space-sm);
  z-index: 100;
  text-decoration: none;
}

.skip-link:focus {
  top: 0;
}

.oxford-theme a:focus-visible,
.oxford-theme button:focus-visible,
.oxford-theme input:focus-visible,
.oxford-theme textarea:focus-visible,
.oxford-theme select:focus-visible {
  outline: 2px solid var(--ct-color-accent);
  outline-offset: 2px;
}

@media (prefers-reduced-motion: reduce) {
  *,
  *::before,
  *::after {
    animation-duration: 0.01ms !important;
    transition-duration: 0.01ms !important;
  }
}


/* ==========================================================================
   14. 响应式
   ========================================================================== */
@media (max-width: 768px) {
  :root {
    --ct-space-2xl: 3rem;
    --ct-space-xl: 2.5rem;
  }

  .hero-section {
    min-height: 50vh;
  }

  .section-padding {
    padding: var(--ct-space-xl) 0;
  }
}


/* ==========================================================================
   15. 工具类
   ========================================================================== */
.text-primary { color: var(--ct-color-primary); }
.text-accent { color: var(--ct-color-accent); }
.text-muted { color: var(--ct-color-text-muted); }
.bg-alt { background: var(--ct-color-bg-alt); }
.bg-dark { background: var(--ct-color-bg-dark); color: #fff; }

.uppercase-label {
  text-transform: uppercase;
  letter-spacing: 0.1em;
  font-size: var(--ct-fs-xs);
  font-weight: 600;
}