/* ���·���ͼ��ʽ */
.article-cover {
  width: 100%;
  height: 200px;
  background-size: cover;
  background-position: center;
  border-radius: 8px;
  position: relative;
  overflow: hidden;
}

.article-cover::before {
  content: '';
  position: absolute;
  top: 0;
  left: 0;
  right: 0;
  bottom: 0;
  background: linear-gradient(135deg, rgba(0,0,0,0.3), rgba(0,0,0,0.1));
  z-index: 1;
}

.article-cover-title {
  position: absolute;
  bottom: 20px;
  left: 20px;
  color: white;
  font-size: 18px;
  font-weight: bold;
  z-index: 2;
  text-shadow: 0 2px 4px rgba(0,0,0,0.5);
}

/* ��ͬ����ķ��汳�� */
.cover-embedded {
  background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
}

.cover-programming {
  background: linear-gradient(135deg, #f093fb 0%, #f5576c 100%);
}

.cover-linux {
  background: linear-gradient(135deg, #4facfe 0%, #00f2fe 100%);
}

.cover-interview {
  background: linear-gradient(135deg, #43e97b 0%, #38f9d7 100%);
}

.cover-blog {
  background: linear-gradient(135deg, #fa709a 0%, #fee140 100%);
}

.cover-raspberry {
  background: linear-gradient(135deg, #a8edea 0%, #fed6e3 100%);
}

.cover-algorithm {
  background: linear-gradient(135deg, #ff9a9e 0%, #fecfef 100%);
}

.cover-hardware {
  background: linear-gradient(135deg, #ffecd2 0%, #fcb69f 100%);
}