frontend/src/App.css

/* Header */
.header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: var(--spacing-2) var(--spacing-4);
  background-color: var(--color-canvas-subtle);
  border-bottom: 1px solid var(--color-border-default);
  position: sticky;
  top: 0;
  z-index: 10;
  backdrop-filter: blur(12px);
  background-color: rgba(22, 27, 34, 0.85);
}

.logo {
  display: flex;
  align-items: center;
  gap: 10px;
  text-decoration: none;
  color: var(--color-fg-default);
}

.logo-icon {
  width: 28px;
  height: 28px;
  border-radius: 4px;
}

.logo-text {
  font-size: 18px;
  font-weight: 600;
  letter-spacing: -0.01em;
}

.header-actions {
  display: flex;
  align-items: center;
  gap: var(--spacing-2);
}

.model-select {
  appearance: none;
  background: var(--color-canvas-default);
  border: 1px solid var(--color-border-default);
  border-radius: 6px;
  color: var(--color-fg-default);
  font-size: 13px;
  font-family: inherit;
  padding: 6px 28px 6px 10px;
  cursor: pointer;
  transition: border-color 0.15s;
  background-image: url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' width='12' height='12' viewBox='0 0 24 24' fill='none' stroke='%23888' stroke-width='2'%3E%3Cpolyline points='6 9 12 15 18 9'/%3E%3C/svg%3E");
  background-repeat: no-repeat;
  background-position: right 8px center;
}

.model-select:hover {
  border-color: var(--color-accent-fg);
}

.model-select:focus {
  outline: none;
  border-color: var(--color-accent-fg);
  box-shadow: 0 0 0 3px rgba(99, 102, 241, 0.15);
}

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

/* Main content */
.main {
  flex: 1;
  padding: var(--spacing-6) 0;
}

.page-title {
  font-size: 32px;
  font-weight: 600;
  margin-bottom: var(--spacing-2);
}

.page-subtitle {
  font-size: 16px;
  color: var(--color-fg-muted);
  margin-bottom: var(--spacing-5);
}

/* Upload section */
.upload-section {
  max-width: 800px;
  margin: 0 auto;
}

.upload-card {
  background-color: var(--color-canvas-subtle);
  border: 1px solid var(--color-border-default);
  border-radius: var(--radius-2);
  overflow: hidden;
  box-shadow: var(--shadow-md);
  transition: box-shadow 0.2s ease;
}

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

.upload-header {
  padding: var(--spacing-3) var(--spacing-4);
  background-color: var(--color-canvas-inset);
  border-bottom: 1px solid var(--color-border-muted);
}

.upload-title {
  font-size: 14px;
  font-weight: 600;
  display: flex;
  align-items: center;
  gap: var(--spacing-2);
}

.upload-title svg {
  width: 16px;
  height: 16px;
  color: var(--color-fg-muted);
}

.upload-body {
  padding: var(--spacing-4);
}

/* Tab content panels */
.tab-panel {
  display: none;
}

.tab-panel.active {
  display: block;
  animation: fadeIn 0.2s ease-out;
}

/* Form groups */
.form-group {
  margin-bottom: var(--spacing-4);
}

.form-label {
  display: block;
  font-size: 14px;
  font-weight: 500;
  color: var(--color-fg-default);
  margin-bottom: var(--spacing-2);
}

.form-hint {
  font-size: 12px;
  color: var(--color-fg-muted);
  margin-top: var(--spacing-1);
}

/* File input styling */
.file-input {
  display: none;
}

.file-selected {
  display: flex;
  align-items: center;
  gap: var(--spacing-3);
  padding: var(--spacing-3);
  background-color: var(--color-canvas-default);
  border: 1px solid var(--color-border-default);
  border-radius: var(--radius-1);
  margin-top: var(--spacing-3);
}

.file-icon {
  width: 32px;
  height: 32px;
  display: flex;
  align-items: center;
  justify-content: center;
  background-color: var(--color-accent-emphasis);
  border-radius: var(--radius-1);
  color: white;
}

.file-info {
  flex: 1;
}

.file-name {
  font-size: 14px;
  font-weight: 500;
  color: var(--color-fg-default);
}

.file-size {
  font-size: 12px;
  color: var(--color-fg-muted);
}

.file-remove {
  padding: var(--spacing-1);
  background: transparent;
  border: none;
  color: var(--color-fg-muted);
  cursor: pointer;
  border-radius: var(--radius-1);
  transition: color var(--transition-fast), background-color var(--transition-fast);
}

.file-remove:hover {
  color: var(--color-danger-fg);
  background-color: rgba(248, 81, 73, 0.1);
}

/* Submit section */
.submit-section {
  display: flex;
  justify-content: flex-end;
  padding-top: var(--spacing-4);
  border-top: 1px solid var(--color-border-muted);
  margin-top: var(--spacing-4);
}

/* Response section */
.response-section {
  margin-top: var(--spacing-5);
}

.response-card {
  background-color: var(--color-canvas-subtle);
  border: 1px solid var(--color-border-default);
  border-radius: var(--radius-2);
  overflow: hidden;
}

.response-header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: var(--spacing-3) var(--spacing-4);
  background-color: var(--color-canvas-inset);
  border-bottom: 1px solid var(--color-border-muted);
}

.response-title {
  font-size: 14px;
  font-weight: 600;
  display: flex;
  align-items: center;
  gap: var(--spacing-2);
}

.response-badge {
  font-size: 12px;
  padding: 2px 8px;
  border-radius: var(--radius-full);
  background-color: var(--color-btn-primary-bg);
  color: white;
}

.response-body {
  padding: var(--spacing-4);
}

.response-text {
  font-size: 14px;
  line-height: 1.7;
  color: var(--color-fg-default);
  white-space: pre-wrap;
}

/* Loading state */
.loading {
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: var(--spacing-3);
  padding: var(--spacing-6);
  color: var(--color-fg-muted);
}

.loading-spinner {
  width: 24px;
  height: 24px;
  border: 2px solid var(--color-border-default);
  border-top-color: var(--color-accent-fg);
  border-radius: 50%;
  animation: spin 0.8s linear infinite;
}

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

/* Footer */
.footer {
  padding: var(--spacing-4);
  text-align: center;
  font-size: 12px;
  color: var(--color-fg-subtle);
  border-top: 1px solid var(--color-border-muted);
}

.footer a {
  color: var(--color-accent-fg);
  text-decoration: none;
}

.footer a:hover {
  text-decoration: underline;
}

/* Inline result */
.inline-result {
  margin-top: var(--spacing-3);
  padding: var(--spacing-3) var(--spacing-4);
  border-radius: var(--radius-1);
  font-size: 13px;
  line-height: 1.6;
  display: flex;
  align-items: flex-start;
  gap: var(--spacing-2);
  border: 1px solid transparent;
}

.inline-result--success {
  background-color: rgba(46, 160, 67, 0.08);
  border-color: rgba(46, 160, 67, 0.3);
  color: var(--color-fg-default);
  flex-direction: column;
  gap: var(--spacing-2);
}

.inline-result--error {
  background-color: rgba(248, 81, 73, 0.08);
  border-color: rgba(248, 81, 73, 0.3);
  color: var(--color-danger-fg);
  align-items: center;
}

.inline-result--loading {
  background-color: var(--color-canvas-inset);
  border-color: var(--color-border-muted);
  color: var(--color-fg-muted);
  align-items: center;
}

.inline-result--streaming {
  background-color: var(--color-canvas-inset);
  border-color: var(--color-accent-emphasis);
  color: var(--color-fg-default);
  flex-direction: column;
  gap: var(--spacing-2);
}

.inline-result--streaming .inline-result__label {
  color: var(--color-accent-fg);
}

.inline-result__label {
  display: flex;
  align-items: center;
  gap: var(--spacing-1);
  font-size: 12px;
  font-weight: 600;
  color: rgba(46, 160, 67, 0.9);
  width: 100%;
}

.inline-result__text {
  font-size: 14px;
  line-height: 1.7;
  color: var(--color-fg-default);
  white-space: pre-wrap;
  margin: 0;
}

/* Streaming cursor blink */
.streaming-cursor {
  animation: blink 0.7s step-end infinite;
  color: var(--color-accent-fg);
  font-weight: 300;
}

@keyframes blink {
  50% {
    opacity: 0;
  }
}

.streaming-placeholder {
  color: var(--color-fg-muted);
  font-style: italic;
}