/* 全局样式重置+基础配置 */
* {
  margin: 0;
  padding: 0;
  box-sizing: border-box;
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "Helvetica Neue", Arial, sans-serif;
}

:root {
  --primary-color: #165DFF;
  --primary-light: #4080FF;
  --primary-gradient: linear-gradient(135deg, #165DFF 0%, #4080FF 100%);
  --secondary-color: #36D399;
  --gray-light: #F5F7FA;
  --gray: #E5E6EB;
  --gray-dark: #969799;
  --text-color: #1D2129;
  --shadow: 0 4px 20px rgba(0, 0, 0, 0.08);
  --shadow-hover: 0 6px 24px rgba(0, 0, 0, 0.12);
  --radius: 12px;
  --transition: all 0.4s cubic-bezier(0.4, 0, 0.2, 1);
}

body {
  background-color: var(--gray-light);
  color: var(--text-color);
  min-height: 100vh;
  padding: 20px 0;
  overflow-x: hidden; /* 禁止横向滚动 */
}

/* 容器布局（整体居中，无纵向滚动） */
.app-container {
  max-width: 1200px;
  margin: 0 auto;
  padding: 0 20px;
}

/* 顶部品牌区 */
.header {
  text-align: center;
  margin-bottom: 30px;
}

.logo {
  font-size: 28px;
  font-weight: 600;
  color: var(--primary-color);
  margin-bottom: 8px;
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 10px;
}

.slogan {
  font-size: 14px;
  color: var(--gray-dark);
  line-height: 1.5;
}

/* 核心布局：左右容器 */
.main-wrap {
  display: flex;
  justify-content: center;
  align-items: flex-start;
  gap: 20px;
  margin-bottom: 30px;
  min-height: calc(100vh - 180px); /* 确保高度适配，无滚动 */
}

/* 左侧上传卡片（始终显示，居中） */
.upload-card {
  background: #FFFFFF;
  border-radius: var(--radius);
  box-shadow: var(--shadow);
  padding: 40px;
  width: 100%;
  max-width: 500px;
  transition: var(--transition);
  animation: fadeIn 0.4s ease;
}

.upload-card:hover {
  box-shadow: var(--shadow-hover);
}

/* 右侧预览卡片（默认隐藏，上传后滑入） */
.preview-card {
  background: #FFFFFF;
  border-radius: var(--radius);
  box-shadow: var(--shadow);
  padding: 24px;
  width: 100%;
  max-width: 500px;
  height: 100%;
  min-height: 500px; /* 与上传区等高 */
  display: none;
  transform: translateX(50px);
  opacity: 0;
  animation: slideIn 0.5s ease forwards;
}

/* 预览区头部 */
.preview-header {
  margin-bottom: 20px;
  padding-bottom: 12px;
  border-bottom: 1px solid var(--gray);
}

.preview-title {
  font-size: 18px;
  font-weight: 500;
  color: var(--text-color);
  margin-bottom: 8px;
}

.preview-name {
  font-size: 13px;
  color: var(--gray-dark);
  white-space: nowrap;
  overflow: hidden;
  text-overflow: ellipsis;
}

/* 预览区内容（图片居中） */
.preview-content {
  display: flex;
  justify-content: center;
  align-items: center;
  height: calc(100% - 60px);
  padding: 10px;
}

.preview-img {
  max-width: 100%;
  max-height: 100%;
  border-radius: 8px;
  box-shadow: 0 2px 12px rgba(0, 0, 0, 0.1);
  object-fit: contain; /* 保持图片比例，不拉伸 */
}

/* 上传区域 */
.upload-section {
  margin-bottom: 30px;
}

.upload-area {
  border: 2px dashed var(--gray);
  border-radius: var(--radius);
  padding: 60px 20px;
  text-align: center;
  cursor: pointer;
  transition: var(--transition);
  position: relative;
  overflow: hidden;
  background-color: #FFFFFF;
}

.upload-area:hover {
  border-color: var(--primary-light);
  background-color: rgba(22, 93, 255, 0.02);
}

.upload-area.active {
  border-color: var(--secondary-color);
  background-color: rgba(54, 211, 153, 0.05);
}

.upload-icon {
  font-size: 56px;
  color: var(--primary-color);
  margin-bottom: 16px;
  transition: var(--transition);
}

.upload-area:hover .upload-icon {
  transform: scale(1.05);
}

.upload-text {
  font-size: 16px;
  color: var(--text-color);
  margin-bottom: 8px;
}

.upload-subtext {
  font-size: 14px;
  color: var(--gray-dark);
}

.upload-btn-text {
  color: var(--primary-color);
  font-weight: 500;
  cursor: pointer;
  text-decoration: underline;
}

/* 配置面板 */
.config-panel {
  display: none;
  margin-bottom: 30px;
  animation: fadeIn 0.4s ease;
}

.config-title {
  font-size: 18px;
  font-weight: 500;
  margin-bottom: 20px;
  color: var(--text-color);
}

.config-items {
  display: flex;
  flex-direction: column;
  gap: 20px;
  margin-bottom: 24px;
}

.config-item {
  display: flex;
  align-items: center;
  gap: 12px;
}

.config-item label {
  width: 90px;
  font-size: 14px;
  color: var(--text-color);
  font-weight: 500;
}

.form-control {
  flex: 1;
  padding: 10px 14px;
  border: 1px solid var(--gray);
  border-radius: 8px;
  font-size: 14px;
  transition: var(--transition);
  background-color: #FFFFFF;
}

.form-control:focus {
  outline: none;
  border-color: var(--primary-color);
  box-shadow: 0 0 0 3px rgba(22, 93, 255, 0.1);
}

.slider-wrap {
  flex: 1;
  display: flex;
  align-items: center;
  gap: 10px;
}

.quality-slider {
  flex: 1;
  height: 6px;
  -webkit-appearance: none;
  appearance: none;
  background: var(--gray);
  border-radius: 3px;
  outline: none;
}

.quality-slider::-webkit-slider-thumb {
  -webkit-appearance: none;
  appearance: none;
  width: 20px;
  height: 20px;
  border-radius: 50%;
  background: var(--primary-color);
  cursor: pointer;
  transition: var(--transition);
  box-shadow: 0 2px 6px rgba(22, 93, 255, 0.3);
}

.quality-slider::-webkit-slider-thumb:hover {
  transform: scale(1.1);
  background: var(--primary-light);
}

.quality-value {
  font-size: 14px;
  color: var(--primary-color);
  font-weight: 500;
  min-width: 30px;
  text-align: center;
}

/* 按钮通用样式 */
.compress-btn, .download-btn, .reset-btn {
  width: 100%;
  padding: 14px 0;
  border: none;
  border-radius: 8px;
  font-size: 16px;
  font-weight: 500;
  cursor: pointer;
  transition: var(--transition);
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 8px;
}

.compress-btn {
  background: var(--primary-gradient);
  color: #FFFFFF;
}

.compress-btn:hover {
  transform: translateY(-2px);
  box-shadow: 0 6px 16px rgba(22, 93, 255, 0.3);
}

.compress-btn:active {
  transform: translateY(0);
}

/* 加载进度 */
.loading-section {
  display: none;
  text-align: center;
  padding: 20px 0;
  animation: fadeIn 0.4s ease;
}

.progress-ring {
  position: relative;
  width: 80px;
  height: 80px;
  margin: 0 auto 16px;
}

.progress-circle {
  width: 100%;
  height: 100%;
  border: 4px solid var(--gray-light);
  border-top: 4px solid var(--primary-color);
  border-radius: 50%;
  animation: spin 1s linear infinite;
}

.progress-text {
  position: absolute;
  top: 50%;
  left: 50%;
  transform: translate(-50%, -50%);
  font-size: 14px;
  font-weight: 500;
  color: var(--primary-color);
}

.loading-text {
  font-size: 14px;
  color: var(--gray-dark);
}

/* 结果面板 */
.result-panel {
  display: none;
  animation: scaleIn 0.4s ease;
}

.result-title {
  font-size: 18px;
  font-weight: 500;
  margin-bottom: 20px;
  color: var(--text-color);
}

.result-stats {
  display: flex;
  flex-direction: column;
  gap: 16px;
  margin-bottom: 24px;
  padding: 20px;
  background-color: var(--gray-light);
  border-radius: 8px;
}

.stat-item {
  display: flex;
  justify-content: space-between;
  font-size: 14px;
}

.stat-label {
  color: var(--gray-dark);
}

.stat-value {
  color: var(--text-color);
  font-weight: 500;
}

.rate-value {
  color: var(--secondary-color);
}

.download-btn {
  background: var(--secondary-color);
  color: #FFFFFF;
  text-decoration: none;
  margin-bottom: 12px;
}

.download-btn:hover {
  background: #2CBF89;
  transform: translateY(-2px);
  box-shadow: 0 6px 16px rgba(54, 211, 153, 0.3);
}

.reset-btn {
  background: #FFFFFF;
  color: var(--primary-color);
  border: 1px solid var(--primary-color);
}

.reset-btn:hover {
  background: rgba(22, 93, 255, 0.05);
}

/* 底部说明 */
.footer {
  margin-top: 20px;
  text-align: center;
  font-size: 12px;
  color: var(--gray-dark);
  line-height: 1.5;
}

/* 动画定义 */
@keyframes fadeIn {
  from { opacity: 0; transform: translateY(10px); }
  to { opacity: 1; transform: translateY(0); }
}

@keyframes scaleIn {
  from { opacity: 0; transform: scale(0.95); }
  to { opacity: 1; transform: scale(1); }
}

@keyframes spin {
  to { transform: rotate(360deg); }
}

/* 右侧预览区滑入动画 */
@keyframes slideIn {
  from { 
    opacity: 0; 
    transform: translateX(50px); 
  }
  to { 
    opacity: 1; 
    transform: translateX(0); 
  }
}

/* 响应式适配（移动端变回上下布局） */
@media (max-width: 992px) {
  .main-wrap {
    flex-direction: column;
    align-items: center;
    gap: 20px;
  }

  .upload-card, .preview-card {
    max-width: 100%;
  }

  .preview-card {
    min-height: 300px;
  }
}

@media (max-width: 576px) {
  .upload-card {
    padding: 24px;
  }
  
  .upload-area {
    padding: 40px 16px;
  }
  
  .upload-icon {
    font-size: 48px;
  }
  
  .config-item {
    flex-direction: column;
    align-items: flex-start;
    gap: 8px;
  }
  
  .config-item label {
    width: 100%;
  }
  
  .result-stats {
    padding: 16px;
  }
}