:root {
  --font-family-base: 'Segoe UI', 'Noto Sans SC', -apple-system, BlinkMacSystemFont, sans-serif;
  --font-size-xs: 10px;
  --font-size-sm: 12px;
  --font-size-base: 13px;
  --font-size-md: 14px;
  --font-size-lg: 16px;
  --font-size-xl: 20px;
  --font-weight-normal: 400;
  --font-weight-medium: 500;
  --font-weight-semibold: 600;
  --font-weight-bold: 700;
  --text-primary: #333333;
  --text-secondary: #818181;
  --text-tertiary: #999999;
  --text-muted: #AAAAAA;
  --text-title: #2c3e50;
  --primary-blue: #409eff;
  --primary-gray: #5b5b5b;
  --success: #67c23a;
  --warning: #e6a23c;
  --danger: #ff4444;
  --link: #409eff;
  --bg-base: #fcfcfc;
  --bg-elevated: #ffffff;
  --bg-input: #F3F3F3;
  --bg-hover: #F5F5F7;
  --bg-active: #E8E8ED;
  --bg-overlay: rgba(255, 255, 255, 0.7);
  --border-light: #F3F3F3;
  --border-base: #e3e3e3;
  --border-medium: #CCCCCC;
  --radius-sm: 8px;
  --radius-md: 12px;
  --radius-lg: 16px;
  --shadow-panel: 0px 10px 32px rgba(51, 51, 51, 0.2);
  --shadow-toast: 0px 4px 12px rgba(0, 0, 0, 0.15);
  --space-1: 4px;
  --space-2: 8px;
  --space-3: 12px;
  --space-4: 16px;
  --space-5: 20px;
  --space-6: 24px;
  --space-8: 32px;
  --space-10: 40px;
}

* {
  box-sizing: border-box;
}

body {
  font-family: var(--font-family-base);
  background-color: var(--bg-base);
  color: var(--text-primary);
  margin: 0;
  padding: 0;
  min-height: 100vh;
}

.app-container {
  display: flex;
  flex-direction: column;
  min-height: 100vh;
}

.header-navbar {
  width: 100%;
  height: 56px;
  display: flex;
  align-items: center;
  justify-content: center;
  padding: 0 16px;
  background-color: var(--bg-elevated);
  border-bottom: 1px solid var(--border-light);
  position: sticky;
  top: 0;
  z-index: 100;
}

.header-left-action {
  position: absolute;
  left: 16px;
}

.header-right-action {
  position: absolute;
  right: 16px;
  display: flex;
  align-items: center;
  gap: 8px;
}

.header-navbar-title {
  font-family: 'Noto Sans SC', sans-serif;
  font-weight: 500;
  font-size: 14px;
  color: var(--text-title);
}

.nav-link {
  font-size: 13px;
  color: var(--link);
  text-decoration: none;
  transition: opacity 0.2s;
}

.nav-link:hover {
  opacity: 0.7;
}

.engine-select {
  padding: 4px 8px;
  border: 1px solid var(--border-base);
  border-radius: 8px;
  background-color: var(--bg-elevated);
  color: var(--text-primary);
  font-size: 13px;
  cursor: pointer;
  transition: all 0.2s ease;
}

.engine-select:hover {
  border-color: var(--border-medium);
  background-color: var(--bg-hover);
}

.theme-toggle {
  width: 28px;
  height: 28px;
  border: none;
  background: none;
  cursor: pointer;
  outline: none;
  display: flex;
  align-items: center;
  justify-content: center;
  color: var(--text-secondary);
  transition: color 0.2s;
}

.theme-toggle:hover {
  color: var(--text-primary);
}

.main-content {
  flex: 1;
  display: flex;
  flex-direction: column;
  padding: 24px;
  max-width: 1200px;
  margin: 0 auto;
  width: 100%;
}

.drop-zone {
  border: 2px dashed var(--border-medium);
  border-radius: 16px;
  padding: 48px 24px;
  text-align: center;
  cursor: pointer;
  transition: all 0.2s ease;
  background-color: var(--bg-elevated);
  margin-bottom: 24px;
}

.drop-zone:hover,
.drop-zone.drag-over {
  border-color: var(--primary-blue);
  background-color: var(--bg-hover);
}

.drop-zone.drag-over {
  border-style: solid;
}

.drop-icon {
  color: var(--text-tertiary);
  margin-bottom: 16px;
}

.drop-text {
  font-size: 20px;
  font-weight: 500;
  color: var(--text-primary);
  margin: 0 0 8px 0;
}

.drop-hint {
  font-size: 14px;
  color: var(--text-secondary);
  margin: 0 0 8px 0;
}

.drop-formats {
  font-size: 12px;
  color: var(--text-tertiary);
  margin: 0 0 16px 0;
}

.engine-selector {
  display: flex;
  align-items: center;
  gap: 8px;
  margin-top: 16px;
  justify-content: center;
}

.engine-selector label {
  font-size: 14px;
  color: var(--text-secondary);
}

.engine-select {
  padding: 8px 12px;
  border: 1px solid var(--border-base);
  border-radius: 8px;
  background-color: var(--bg-elevated);
  color: var(--text-primary);
  font-size: 14px;
  cursor: pointer;
  transition: all 0.2s ease;
}

.engine-select:hover {
  border-color: var(--border-medium);
}

.engine-select:focus {
  outline: none;
  border-color: var(--primary-blue);
  box-shadow: 0 0 0 2px rgba(64, 158, 255, 0.2);
}

.image-list {
  flex: 1;
  display: flex;
  flex-direction: column;
  gap: 12px;
  margin-bottom: 24px;
}

.image-card {
  display: flex;
  align-items: center;
  padding: 16px;
  background-color: var(--bg-elevated);
  border: 1px solid var(--border-light);
  border-radius: 12px;
  transition: all 0.2s ease;
}

.image-card:hover {
  border-color: var(--border-medium);
}

.image-card.compressing {
  opacity: 0.8;
}

.image-card.completed {
  border-color: var(--success);
}

.image-card.error {
  border-color: var(--danger);
}

.image-thumb {
  width: 80px;
  height: 80px;
  border-radius: 8px;
  overflow: hidden;
  background-color: var(--bg-input);
  flex-shrink: 0;
  margin-right: 16px;
  display: flex;
  align-items: center;
  justify-content: center;
}

.image-thumb img {
  max-width: 100%;
  max-height: 100%;
  object-fit: contain;
}

.image-info {
  flex: 1;
  min-width: 0;
}

.image-name {
  font-size: 14px;
  font-weight: 500;
  color: var(--text-primary);
  margin: 0 0 8px 0;
  white-space: nowrap;
  overflow: hidden;
  text-overflow: ellipsis;
}

.image-stats {
  display: flex;
  align-items: center;
  gap: 16px;
  font-size: 13px;
  color: var(--text-secondary);
  margin-bottom: 12px;
}

.image-stats .original-size {
  color: var(--text-tertiary);
}

.image-stats .compressed-size {
  color: var(--success);
  font-weight: 500;
}

.image-stats .rate {
  color: var(--primary-blue);
  font-weight: 500;
}

.quality-control {
  display: flex;
  align-items: center;
  gap: 12px;
}

.quality-label {
  font-size: 12px;
  color: var(--text-secondary);
  white-space: nowrap;
}

.quality-slider {
  flex: 1;
  height: 4px;
  background: var(--bg-input);
  border-radius: 2px;
  outline: none;
  -webkit-appearance: none;
  appearance: none;
}

.quality-slider::-webkit-slider-thumb {
  -webkit-appearance: none;
  width: 16px;
  height: 16px;
  background: var(--primary-blue);
  border-radius: 50%;
  cursor: pointer;
  transition: transform 0.1s;
}

.quality-slider::-webkit-slider-thumb:hover {
  transform: scale(1.2);
}

.quality-slider::-moz-range-thumb {
  width: 16px;
  height: 16px;
  background: var(--primary-blue);
  border-radius: 50%;
  cursor: pointer;
  border: none;
}

.quality-value {
  font-size: 12px;
  font-weight: 500;
  color: var(--text-primary);
  min-width: 36px;
  text-align: right;
}

.image-actions {
  display: flex;
  flex-direction: column;
  gap: 8px;
  margin-left: 16px;
}

.image-status {
  font-size: 12px;
  color: var(--text-tertiary);
  text-align: center;
  min-height: 20px;
}

.image-status.compressing {
  color: var(--primary-blue);
}

.image-status.completed {
  color: var(--success);
}

.image-status.error {
  color: var(--danger);
}

.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  padding: 0 12px;
  height: 28px;
  border-radius: 8px;
  border: 1px solid var(--border-base);
  background-color: var(--bg-elevated);
  color: var(--text-primary);
  font-size: 13px;
  font-weight: 400;
  cursor: pointer;
  transition: all 0.2s ease;
  white-space: nowrap;
}

.btn:hover {
  background-color: var(--bg-hover);
  border-color: var(--border-medium);
}

.btn:active {
  background-color: var(--bg-active);
}

.btn:disabled {
  opacity: 0.5;
  cursor: not-allowed;
}

.btn-icon {
  margin-right: 4px;
}

.btn-primary {
  background-color: var(--primary-gray);
  border-color: var(--primary-gray);
  color: white;
}

.btn-primary:hover {
  background-color: #6b6b6b;
  border-color: #6b6b6b;
}

.btn-download {
  background-color: var(--success);
  border-color: var(--success);
  color: white;
}

.btn-download:hover {
  background-color: #5cb832;
  border-color: #5cb832;
}

.btn-small {
  padding: 0 8px;
  height: 24px;
  font-size: 12px;
}

.btn-large-primary {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  padding: 0 20px;
  height: 44px;
  border-radius: 12px;
  border: 1px solid var(--border-base);
  background-color: var(--bg-elevated);
  color: var(--text-primary);
  font-size: 14px;
  font-weight: 400;
  cursor: pointer;
  transition: all 0.2s ease;
}

.btn-large-primary:hover {
  background-color: var(--bg-hover);
  border-color: var(--border-medium);
}

.btn-large-primary:disabled {
  opacity: 0.5;
  cursor: not-allowed;
}

.btn-large-secondary {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  padding: 0 20px;
  height: 44px;
  border-radius: 12px;
  border: 1px solid var(--primary-gray);
  background-color: var(--primary-gray);
  color: white;
  font-size: 14px;
  font-weight: 400;
  cursor: pointer;
  transition: all 0.2s ease;
}

.btn-large-secondary:hover {
  background-color: #6b6b6b;
  border-color: #6b6b6b;
}

.btn-large-secondary:disabled {
  opacity: 0.5;
  cursor: not-allowed;
}

.btn-large-danger {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  padding: 0 20px;
  height: 44px;
  border-radius: 12px;
  border: 1px solid var(--border-base);
  background-color: var(--bg-elevated);
  color: var(--danger);
  font-size: 14px;
  font-weight: 400;
  cursor: pointer;
  transition: all 0.2s ease;
}

.btn-large-danger:hover {
  background-color: var(--danger);
  border-color: var(--danger);
  color: white;
}

.btn-large-danger:disabled {
  opacity: 0.5;
  cursor: not-allowed;
}

.footer-bar {
  background-color: var(--bg-elevated);
  border: 1px solid var(--border-light);
  border-radius: 16px;
  padding: 16px 20px;
  display: flex;
  align-items: center;
  justify-content: space-between;
  box-shadow: var(--shadow-panel);
}

.footer-actions {
  display: flex;
  gap: 12px;
}

.footer-stats {
  display: flex;
  align-items: center;
  gap: 24px;
  font-size: 13px;
  color: var(--text-secondary);
}

.stats-item strong {
  color: var(--text-primary);
  font-weight: 500;
}

.toast-container {
  position: fixed;
  top: 72px;
  left: 50%;
  transform: translateX(-50%);
  z-index: 9999;
  pointer-events: none;
}

.toast-message {
  background: var(--bg-elevated);
  border: 1px solid var(--border-base);
  border-radius: 8px;
  padding: 12px 20px;
  font-size: 14px;
  color: var(--text-primary);
  box-shadow: var(--shadow-toast);
  white-space: nowrap;
  opacity: 0;
  transform: translateY(-10px);
  transition: all 0.3s ease;
  pointer-events: auto;
}

.toast-message.show {
  opacity: 1;
  transform: translateY(0);
}

.toast-message.success {
  border-color: var(--success);
  color: var(--success);
}

.toast-message.error {
  border-color: var(--danger);
  color: var(--danger);
}

.drop-overlay {
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  bottom: 0;
  background-color: var(--bg-overlay);
  backdrop-filter: blur(30px);
  -webkit-backdrop-filter: blur(30px);
  z-index: 9999;
  display: flex;
  align-items: center;
  justify-content: center;
  opacity: 0;
  pointer-events: none;
  transition: opacity 0.2s ease;
}

.drop-overlay.show {
  opacity: 1;
  pointer-events: auto;
}

.drop-hint-overlay {
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 24px;
  outline: 4px dashed var(--text-primary);
  outline-offset: -80px;
  border-radius: 100px;
  width: 100%;
  height: 100%;
  justify-content: center;
}

.drop-hint-text {
  font-size: 40px;
  font-weight: 500;
  color: var(--text-primary);
}

.progress-bar {
  width: 100%;
  height: 4px;
  background: var(--bg-input);
  border-radius: 2px;
  overflow: hidden;
  margin-top: 8px;
}

.progress-fill {
  height: 100%;
  background: var(--primary-blue);
  border-radius: 2px;
  transition: width 0.3s ease;
}

.empty-state {
  text-align: center;
  padding: 48px 24px;
  color: var(--text-tertiary);
}

.empty-state-icon {
  font-size: 48px;
  margin-bottom: 16px;
}

.empty-state-text {
  font-size: 16px;
}

@media (max-width: 768px) {
  .main-content {
    padding: 16px;
  }

  .drop-zone {
    padding: 32px 16px;
  }

  .drop-text {
    font-size: 18px;
  }

  .image-card {
    flex-direction: column;
    align-items: flex-start;
  }

  .image-thumb {
    margin-right: 0;
    margin-bottom: 12px;
    width: 100%;
    height: 120px;
  }

  .image-actions {
    flex-direction: row;
    margin-left: 0;
    margin-top: 12px;
    width: 100%;
  }

  .footer-bar {
    flex-direction: column;
    gap: 16px;
  }

  .footer-actions {
    width: 100%;
    justify-content: center;
    flex-wrap: wrap;
  }

  .footer-stats {
    flex-wrap: wrap;
    justify-content: center;
    gap: 12px;
  }

  .btn-large-primary,
  .btn-large-secondary,
  .btn-large-danger {
    padding: 0 16px;
    height: 40px;
    font-size: 13px;
  }
}

body.dark-mode {
  --bg-base: #1a1a1a;
  --bg-elevated: #2a2a2a;
  --bg-input: #3a3a3a;
  --bg-hover: #333333;
  --bg-active: #404040;
  --bg-overlay: rgba(0, 0, 0, 0.7);
  --text-primary: #e0e0e0;
  --text-secondary: #999999;
  --text-tertiary: #808080;
  --text-title: #e0e0e0;
  --border-light: #404040;
  --border-base: #404040;
  --border-medium: #505050;
  --link: #66b1ff;
  --shadow-panel: 0px 10px 32px rgba(0, 0, 0, 0.5);
  --shadow-toast: 0px 4px 12px rgba(0, 0, 0, 0.5);
}

body.dark-mode .drop-hint-overlay {
  outline-color: #F5F5F5;
}

body.dark-mode .drop-hint-text {
  color: #F5F5F5;
}