:root {
  --primary: #2563eb;
  --primary-hover: #1d4ed8;
  --bg-color: #f8fafc;
  --card-bg: #ffffff;
  --text-main: #0f172a;
  --text-muted: #64748b;
  --border: #e2e8f0;
  --border-focus: #94a3b8;
  --success: #10b981;
  --error: #ef4444;
  --font-sans: 'Inter', system-ui, -apple-system, sans-serif;
}

* {
  box-sizing: border-box;
  margin: 0;
  padding: 0;
}

body {
  font-family: var(--font-sans);
  background-color: var(--bg-color);
  color: var(--text-main);
  min-height: 100vh;
  display: flex;
  justify-content: center;
  align-items: center;
}

.app-container {
  width: 100%;
  max-width: 600px;
  background: var(--card-bg);
  border-radius: 16px;
  box-shadow: 0 10px 25px -5px rgba(0, 0, 0, 0.05), 0 8px 10px -6px rgba(0, 0, 0, 0.01);
  overflow: hidden;
  display: flex;
  flex-direction: column;
}

.app-header {
  padding: 32px 32px 24px;
  border-bottom: 1px solid var(--border);
  text-align: center;
}

.logo-container {
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 12px;
  margin-bottom: 16px;
}

.logo-container h1 {
  font-size: 1.5rem;
  font-weight: 700;
  color: var(--text-main);
}

.subtitle {
  color: var(--text-muted);
  font-size: 0.95rem;
  line-height: 1.5;
}

.app-main {
  padding: 32px;
}

.dropzone {
  border: 2px dashed var(--border);
  border-radius: 12px;
  padding: 40px 24px;
  text-align: center;
  transition: all 0.2s ease;
  background-color: #fcfcfd;
  position: relative;
}

.dropzone.is-dragging {
  border-color: var(--primary);
  background-color: #eff6ff;
}

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

.dropzone-text {
  font-weight: 500;
  margin-bottom: 8px;
}

.dropzone-subtext {
  color: var(--text-muted);
  font-size: 0.875rem;
  margin-bottom: 16px;
}

.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 8px;
  padding: 10px 20px;
  font-weight: 600;
  font-size: 0.95rem;
  border-radius: 8px;
  cursor: pointer;
  transition: all 0.2s ease;
  border: none;
}

.btn:disabled {
  opacity: 0.6;
  cursor: not-allowed;
}

.btn-secondary {
  background-color: #f1f5f9;
  color: var(--text-main);
}

.btn-secondary:hover {
  background-color: #e2e8f0;
}

.btn-primary {
  background-color: var(--primary);
  color: white;
  width: 100%;
  padding: 14px;
  font-size: 1rem;
}

.btn-primary:hover:not(:disabled) {
  background-color: var(--primary-hover);
}

.btn-icon {
  background: none;
  border: none;
  color: var(--text-muted);
  cursor: pointer;
  padding: 4px;
  border-radius: 4px;
}

.btn-icon:hover {
  background: #f1f5f9;
  color: var(--error);
}

.file-info {
  margin-top: 24px;
  padding: 12px 16px;
  background: white;
  border: 1px solid var(--border);
  border-radius: 8px;
  display: flex;
  align-items: center;
  gap: 12px;
  text-align: left;
}

.file-info span {
  flex: 1;
  font-size: 0.9rem;
  font-weight: 500;
  overflow: hidden;
  text-overflow: ellipsis;
  white-space: nowrap;
}

.actions {
  margin-top: 24px;
}

.hidden {
  display: none !important;
}

.status-area {
  margin-top: 24px;
  padding: 16px;
  border-radius: 8px;
  text-align: center;
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 12px;
}

.status-message {
  font-size: 0.9rem;
  font-weight: 500;
}

.status-area.error {
  background-color: #fef2f2;
  color: var(--error);
  border: 1px solid #fecaca;
}

.status-area.success {
  background-color: #f0fdf4;
  color: var(--success);
  border: 1px solid #bbf7d0;
}

/* Loader spinner */
.loader {
  border: 3px solid rgba(0, 0, 0, 0.05);
  border-top-color: var(--primary);
  border-radius: 50%;
  width: 24px;
  height: 24px;
  animation: spin 1s linear infinite;
}

@keyframes spin {
  0% { transform: rotate(0deg); }
  100% { transform: rotate(360deg); }
}

.app-footer {
  padding: 16px;
  text-align: center;
  border-top: 1px solid var(--border);
  color: var(--text-muted);
  font-size: 0.8rem;
  background-color: #f8fafc;
}