/* 全局基础样式，采用苹果风格的浅色调和现代感字体 */
body {
  margin: 0;
  padding: 0;
  font-family: 'San Francisco', 'PingFang SC', 'Helvetica Neue', Arial, sans-serif;
  background: #f7f7fa; /* 苹果风格浅灰背景 */
  color: #222;
  min-height: 100vh;
  display: flex;
  flex-direction: column;
}

/* 顶部导航栏样式 */
.navbar {
  display: flex;
  align-items: center;
  padding: 24px 32px 16px 32px;
  background: #fff;
  box-shadow: 0 2px 8px rgba(0,0,0,0.04);
  border-bottom: 1px solid #ececec;
}

.logo {
  width: 36px;
  height: 36px;
  background: url('https://img.icons8.com/ios-filled/50/000000/mac-os.png') no-repeat center/cover;
  border-radius: 12px;
  margin-right: 16px;
}

.site-title {
  font-size: 2rem;
  font-weight: 600;
  letter-spacing: 2px;
  color: #222;
}

/* 主操作区容器，居中显示 */
.container {
  flex: 1;
  display: flex;
  flex-direction: column;
  align-items: center;
  padding: 32px 16px 0 16px;
}

/* 上传与压缩设置区域 */
.upload-section {
  display: flex;
  flex-direction: column;
  align-items: center;
  margin-bottom: 32px;
  gap: 20px;
}

/* 上传按钮样式 */
.upload-btn {
  display: inline-block;
  padding: 12px 32px;
  background: linear-gradient(90deg, #e0e5ec 0%, #f7f7fa 100%);
  color: #007aff;
  font-size: 1.1rem;
  border-radius: 24px;
  box-shadow: 0 2px 8px rgba(0,0,0,0.06);
  cursor: pointer;
  font-weight: 500;
  transition: background 0.2s, box-shadow 0.2s;
  border: none;
  outline: none;
  position: relative;
}
.upload-btn:hover {
  background: #eaf1fb;
  box-shadow: 0 4px 16px rgba(0,122,255,0.08);
}

/* 压缩比例滑块区域 */
.slider-group {
  display: flex;
  align-items: center;
  gap: 10px;
  font-size: 1rem;
  color: #555;
}
#qualityRange {
  accent-color: #007aff; /* 苹果蓝 */
  width: 160px;
}
#qualityValue {
  min-width: 36px;
  color: #007aff;
  font-weight: bold;
}

/* 预览区布局，响应式两列 */
.preview-section {
  display: flex;
  gap: 32px;
  justify-content: center;
  flex-wrap: wrap;
  margin-bottom: 32px;
}

/* 预览卡片样式 */
.preview-card {
  background: #fff;
  border-radius: 24px;
  box-shadow: 0 4px 24px rgba(0,0,0,0.06);
  padding: 24px 32px;
  min-width: 260px;
  max-width: 320px;
  display: flex;
  flex-direction: column;
  align-items: center;
  margin-bottom: 16px;
  transition: box-shadow 0.2s;
}
.preview-card:hover {
  box-shadow: 0 8px 32px rgba(0,122,255,0.10);
}

.preview-card h2 {
  font-size: 1.1rem;
  color: #007aff;
  margin-bottom: 12px;
  font-weight: 600;
  letter-spacing: 1px;
}

/* 图片预览样式 */
.preview-img {
  width: 180px;
  height: 180px;
  object-fit: contain;
  background: #f0f0f3;
  border-radius: 16px;
  margin-bottom: 12px;
  box-shadow: 0 2px 8px rgba(0,0,0,0.04);
  border: 1px solid #ececec;
}

/* 文件大小信息 */
.file-info {
  font-size: 0.95rem;
  color: #888;
  margin-bottom: 8px;
}

/* 下载按钮样式 */
.download-btn {
  padding: 10px 28px;
  background: #007aff;
  color: #fff;
  border: none;
  border-radius: 20px;
  font-size: 1rem;
  font-weight: 500;
  cursor: pointer;
  margin-top: 8px;
  box-shadow: 0 2px 8px rgba(0,122,255,0.10);
  transition: background 0.2s, box-shadow 0.2s;
}
.download-btn:disabled {
  background: #b0cfff;
  cursor: not-allowed;
}
.download-btn:hover:not(:disabled) {
  background: #005ecb;
  box-shadow: 0 4px 16px rgba(0,122,255,0.18);
}

/* 底部说明 */
.footer {
  text-align: center;
  color: #aaa;
  font-size: 0.95rem;
  padding: 24px 8px 16px 8px;
  background: transparent;
  letter-spacing: 1px;
}

/* 响应式设计：手机端单列显示 */
@media (max-width: 700px) {
  .preview-section {
    flex-direction: column;
    align-items: center;
    gap: 20px;
  }
  .container {
    padding: 16px 4px 0 4px;
  }
  .preview-card {
    min-width: 90vw;
    max-width: 98vw;
    padding: 16px 8px;
  }
}