/* 图片占位符样式 */
.placeholder {
    position: relative;
    background-color: #f0f0f0;
    overflow: hidden;
    border-radius: 8px;
    box-shadow: 0 4px 10px rgba(0, 0, 0, 0.1);
}

.placeholder::before {
    content: attr(data-title);
    position: absolute;
    top: 50%;
    left: 50%;
    transform: translate(-50%, -50%);
    color: #555;
    font-weight: bold;
    text-align: center;
    z-index: 1;
}

.placeholder::after {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background: linear-gradient(135deg, rgba(41, 98, 255, 0.2) 0%, rgba(59, 130, 246, 0.1) 100%);
}

/* 应用预览图占位符 */
.app-preview-placeholder {
    width: 100%;
    height: 400px;
}

/* 截图占位符 */
.screenshot-placeholder {
    width: 100%;
    height: 200px;
}