/* 与3D实验平台风格统一的配色，系统字体 */
* {
  margin: 0;
  padding: 0;
  box-sizing: border-box;
}

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

body {
  font-family: system-ui, -apple-system, 'Segoe UI', Roboto, 'Helvetica Neue', sans-serif;
  background: #E6F3FF;
  color: #262626;
  line-height: 1.6;
  padding-bottom: 60px;
}

.container {
  max-width: 1200px;
  margin: 0 auto;
  padding: 20px;
}

/* 头部 */
.site-header {
  background: linear-gradient(135deg, #2C5282 0%, #1E3A5F 100%);
  color: white;
  padding: 24px 0;
  margin-bottom: 30px;
  box-shadow: 0 2px 8px rgba(0,0,0,0.15);
}
.site-header .container {
  display: flex;
  justify-content: space-between;
  align-items: flex-start;
}
.header-content {
  flex: 1;
}
.header-left {
  display: flex;
  flex-direction: column;
  gap: 8px;
}
.site-header h1 {
  font-size: 1.8rem;
  margin-bottom: 0;
  font-weight: 600;
}
.site-header > .container > .header-content > .header-left > p {
  font-size: 1rem;
  opacity: 0.9;
}
.contact-info {
  font-size: 0.9rem !important;
  color: rgba(255,255,255,0.8) !important;
}
.wechat-qrcode {
  display: flex;
  align-items: center;
  gap: 10px;
  margin-top: 8px;
}
.wechat-qrcode img {
  width: 80px;
  height: 80px;
  border-radius: 8px;
  border: 2px solid rgba(255,255,255,0.3);
  background: white;
}
.wechat-qrcode span {
  font-size: 0.85rem;
  color: rgba(255,255,255,0.8);
}
.back-link {
  display: inline-block;
  color: #FFD966;
  text-decoration: none;
  transition: opacity 0.2s;
  white-space: nowrap;
}
.back-link:hover {
  opacity: 0.8;
  text-decoration: underline;
}

/* 面包屑 */
.breadcrumb {
  margin-bottom: 20px;
  font-size: 0.9rem;
  color: #595959;
  padding: 12px 16px;
  background: white;
  border-radius: 8px;
  box-shadow: 0 1px 3px rgba(0,0,0,0.05);
}
.breadcrumb nav {
  display: inline;
}
.breadcrumb ol {
  list-style: none;
  display: inline-flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 8px;
}
.breadcrumb li {
  display: inline-flex;
  align-items: center;
}
.breadcrumb li:not(:last-child)::after {
  content: "›";
  margin-left: 8px;
  color: #8C8C8C;
}
.breadcrumb a {
  color: #1890FF;
  text-decoration: none;
}
.breadcrumb a:hover {
  text-decoration: underline;
}
.breadcrumb [aria-current="page"] {
  color: #595959;
  font-weight: 500;
}

/* 教学设计主卡片 */
.design-card {
  background: white;
  border-radius: 24px;
  box-shadow: 0 8px 20px rgba(0,0,0,0.08);
  padding: 30px;
  margin-bottom: 30px;
  border: 1px solid #E6F0FA;
}

.design-header {
  margin-bottom: 25px;
}
.design-title-row {
  display: flex;
  align-items: flex-start;
  justify-content: space-between;
  gap: 24px;
  margin-bottom: 16px;
}
.design-header-right {
  display: flex;
  flex-direction: column;
  align-items: flex-end;
  gap: 6px;
  flex-shrink: 0;
}

.design-title {
  font-size: 1.8rem;
  color: #2C5282;
  margin-bottom: 0;
  border-left: 5px solid #52C41A;
  padding-left: 20px;
  flex: 1;
}

.design-meta {
  color: #666;
  font-size: 0.9rem;
  padding-bottom: 0;
  border-bottom: 1px solid #E6F0FA;
  display: flex;
  flex-wrap: wrap;
  gap: 16px;
}
.design-meta span {
  display: inline-flex;
  align-items: center;
  gap: 4px;
}

/* 按钮样式 */
.btn-3d {
  display: inline-block;
  background: linear-gradient(135deg, #1890FF 0%, #40A9FF 100%);
  color: white;
  padding: 12px 24px;
  border-radius: 40px;
  text-decoration: none;
  font-weight: 600;
  font-size: 1rem;
  transition: all 0.3s;
  box-shadow: 0 4px 12px rgba(24, 144, 255, 0.3);
  text-align: center;
  white-space: nowrap;
}
.btn-3d:hover {
  background: linear-gradient(135deg, #40A9FF 0%, #69C0FF 100%);
  transform: translateY(-2px);
  box-shadow: 0 6px 16px rgba(24, 144, 255, 0.4);
}

.btn-hint {
  font-size: 0.8rem;
  color: #8C8C8C;
  text-align: right;
  margin: 0;
}

/* 教案正文样式 */
.teaching-section {
  margin-bottom: 30px;
}
.teaching-section h2 {
  font-size: 1.3rem;
  color: #2C5282;
  margin-bottom: 12px;
  margin-top: 0;
  font-weight: 600;
}
.teaching-section h3 {
  font-size: 1.1rem;
  color: #1E3A5F;
  margin: 16px 0 8px;
  font-weight: 500;
}
.teaching-section p, .teaching-section li {
  color: #333;
}
.teaching-section ul, .teaching-section ol {
  margin-left: 24px;
  margin-bottom: 16px;
}
.teaching-section li {
  margin-bottom: 8px;
}

/* ========== PPT水印样式 ========== */
.ppt-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(200px, 1fr));
  gap: 16px;
  margin-top: 20px;
}
.ppt-item {
  background: #F8F9FA;
  border-radius: 12px;
  overflow: hidden;
  cursor: pointer;
  transition: transform 0.2s, box-shadow 0.2s;
  border: 1px solid #E6E6E6;
  position: relative;
}
.ppt-item:hover {
  transform: translateY(-4px);
  box-shadow: 0 8px 16px rgba(0,0,0,0.1);
}
.ppt-item img {
  width: 100%;
  height: auto;
  display: block;
}
.ppt-caption {
  padding: 8px;
  font-size: 0.8rem;
  color: #595959;
  text-align: center;
  background: white;
}

/* 半透明水印 */
.watermark-overlay {
  position: absolute;
  top: 50%;
  left: 50%;
  transform: translate(-50%, -50%) rotate(-30deg);
  font-size: 1.5rem;
  font-weight: bold;
  color: rgba(255, 0, 0, 0.2);
  white-space: nowrap;
  pointer-events: none;
  z-index: 10;
  text-shadow: 1px 1px 2px rgba(255,255,255,0.8);
  user-select: none;
}
.ppt-note {
  margin-top: 12px;
  font-size: 0.85rem;
  color: #8C8C8C;
}

/* ========== 版权声明样式 ========== */
.copyright-section {
  margin-top: 40px;
  padding: 20px;
  background: #FFF9E6;
  border: 1px solid #FFE58F;
  border-radius: 12px;
}
.copyright-section h2 {
  color: #D48806 !important;
  font-size: 1.1rem !important;
  margin-bottom: 12px !important;
}
.copyright-content {
  color: #595959;
  font-size: 0.9rem;
  line-height: 1.8;
}
.author-credit {
  margin-top: 12px;
  font-size: 0.85rem;
  color: #8C8C8C;
}
.author-credit a {
  color: #1890FF;
  text-decoration: none;
}
.author-credit a:hover {
  text-decoration: underline;
}

/* 总览页样式 */
.version-grid {
  margin-bottom: 30px;
}
.version-title {
  font-size: 1.6rem;
  color: #2C5282;
  margin: 20px 0 15px;
  padding-bottom: 6px;
  border-bottom: 2px solid #52C41A;
  font-weight: 600;
}
.grade-section {
  margin-bottom: 25px;
}
.grade-title {
  font-size: 1.3rem;
  color: #1E3A5F;
  margin: 15px 0 10px;
  font-weight: 500;
}
.experiment-list {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(250px, 1fr));
  gap: 12px;
  list-style: none;
  margin-left: 0;
  padding-left: 0;
}
.experiment-list li a {
  display: block;
  background: white;
  padding: 12px 18px;
  border-radius: 28px;
  border: 1px solid #D9D9D9;
  color: #2C5282;
  text-decoration: none;
  transition: all 0.2s;
  font-weight: 500;
}
.experiment-list li a:hover {
  background: #E6F7FF;
  border-color: #1890FF;
  transform: translateX(3px);
}
.experiment-list li a:focus {
  outline: 2px solid #1890FF;
  outline-offset: 2px;
}

.update-note {
  margin-top: 30px;
  text-align: center;
  color: #666;
  font-size: 0.9rem;
}

/* 页脚 */
.site-footer {
  text-align: center;
  padding: 24px;
  color: #8C8C8C;
  font-size: 0.85rem;
  border-top: 1px solid #E6F0FA;
  margin-top: 20px;
}

/* ICP备案信息 */
.icp-footer {
  position: fixed;
  bottom: 0;
  left: 0;
  width: 100%;
  background: #fff;
  padding: 8px 0;
  text-align: center;
  font-size: 12px;
  color: #999;
  border-top: 1px solid #eee;
  z-index: 9999;
}
.icp-footer p {
  margin: 0;
}
.icp-footer a {
  color: #999;
  text-decoration: none;
}
.icp-footer a:hover {
  text-decoration: underline;
}

/* 响应式 */
@media (max-width: 768px) {
  .container {
    padding: 12px;
  }
  .design-card {
    padding: 20px;
  }
  .design-title {
    font-size: 1.4rem;
    padding-left: 12px;
  }
  .design-title-row {
    flex-direction: column;
    gap: 16px;
  }
  .design-header-right {
    align-items: flex-start;
    width: 100%;
  }
  .btn-3d {
    width: 100%;
    text-align: center;
  }
  .btn-hint {
    text-align: center;
  }
  .ppt-grid {
    grid-template-columns: repeat(auto-fill, minmax(150px, 1fr));
  }
  .site-header > .container {
    flex-direction: column;
    gap: 12px;
  }
  .wechat-qrcode {
    display: none;
  }
  body {
    padding-bottom: 80px;
  }
  .watermark-overlay {
    font-size: 1rem;
  }
}