:root {
  --primary-color: #3b82f6; /* Modern Blue */
  --primary-hover: #2563eb;
  --bg-color: #f3f4f6;
  --card-bg: #ffffff;
  --text-main: #1f2937;
  --text-secondary: #6b7280;
  --border-color: #e5e7eb;
  --success-color: #10b981;
  --warning-color: #f59e0b;
  --error-color: #ef4444;
  --info-color: #3b82f6;
  --radius: 16px;
  --shadow: 0 10px 25px -5px rgba(0, 0, 0, 0.1), 0 8px 10px -6px rgba(0, 0, 0, 0.1);
}

body {
  font-family: 'Inter', system-ui, -apple-system, sans-serif;
  background-color: var(--bg-color);
  color: var(--text-main);
  margin: 0;
  height: 100vh;
  display: flex;
  justify-content: center;
  align-items: center;
}

#app {
  background: var(--card-bg);
  padding: 3rem;
  border-radius: var(--radius);
  box-shadow: var(--shadow);
  width: 90%;
  max-width: 800px;
  text-align: center;
  display: flex;
  flex-direction: column;
  gap: 1.5rem;
  box-sizing: border-box;
}

h1 {
  margin: 0 0 0.5rem 0;
  font-size: 2rem;
  font-weight: 700;
  color: #111827;
  letter-spacing: -0.025em;
}

#app > p {
  color: var(--text-secondary);
  margin: 0;
  font-size: 1rem;
  line-height: 1.5;
}

/* Drop Zone */
#drop-zone {
  width: 100%;
  height: 320px;
  border: 2px dashed var(--border-color);
  border-radius: var(--radius);
  background-color: #f9fafb;
  display: flex;
  flex-direction: column;
  justify-content: center;
  align-items: center;
  transition: all 0.2s ease;
  position: relative;
  overflow: hidden;
  cursor: pointer;
  box-sizing: border-box;
  margin-top: 1rem;
}

#drop-zone:hover, #drop-zone.dragover {
  border-color: var(--primary-color);
  background-color: #eff6ff;
}

#drop-zone.highlight {
  border-color: var(--primary-color);
  background-color: #eff6ff;
}

/* Empty State */
.drop-zone-empty {
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 0.75rem;
  pointer-events: none;
}

.drop-zone-icon {
  font-size: 3.5rem;
  margin-bottom: 0.5rem;
  opacity: 0.8;
}

.drop-zone-title {
  font-weight: 600;
  font-size: 1.125rem;
  color: var(--text-main);
}

.drop-zone-desc {
  font-size: 0.875rem;
  color: var(--text-secondary);
}

.drop-zone-sub {
  font-size: 0.75rem;
  color: #9ca3af;
  margin-top: 0.5rem;
}

/* File List */
.file-list {
  width: 100%;
  height: 100%;
  overflow-y: auto;
  padding: 1rem;
  box-sizing: border-box;
  display: flex;
  flex-direction: column;
  gap: 0.5rem;
  align-self: stretch;
}

.file-list::-webkit-scrollbar {
  width: 6px;
}
.file-list::-webkit-scrollbar-thumb {
  background-color: #d1d5db;
  border-radius: 3px;
}

.file-item {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 0.75rem 1rem;
  background: white;
  border: 1px solid var(--border-color);
  border-radius: 8px;
  font-size: 0.875rem;
  transition: transform 0.1s, box-shadow 0.1s;
}

.file-item:hover {
  transform: translateY(-1px);
  box-shadow: 0 4px 6px -1px rgba(0, 0, 0, 0.05);
  border-color: #d1d5db;
}

.file-info {
  display: flex;
  align-items: center;
  gap: 0.75rem;
  flex: 1;
  min-width: 0;
  text-align: left;
}

.file-icon {
    font-size: 1.25rem;
}

.file-path {
  white-space: nowrap;
  overflow: hidden;
  text-overflow: ellipsis;
  font-weight: 500;
  color: var(--text-main);
}

.file-meta {
  display: flex;
  align-items: center;
  gap: 1rem;
  flex-shrink: 0;
  margin-left: 1rem;
}

.file-status {
  display: flex;
  align-items: center;
  gap: 0.375rem;
  font-size: 0.75rem;
  font-weight: 600;
  text-transform: uppercase;
  letter-spacing: 0.025em;
  padding: 0.25rem 0.5rem;
  border-radius: 4px;
  background-color: #f3f4f6;
}

.status-pending { color: var(--text-secondary); background-color: #f3f4f6; }
.status-processing { color: var(--info-color); background-color: #eff6ff; }
.status-compiled { color: var(--success-color); background-color: #ecfdf5; }
.status-copied { color: #0ea5e9; background-color: #f0f9ff; }
.status-fallback { color: var(--warning-color); background-color: #fffbeb; }

.file-size {
  color: var(--text-secondary);
  font-family: 'SF Mono', 'Roboto Mono', monospace;
  font-size: 0.75rem;
}

/* Status Bar */
#status {
  min-height: 1.5rem;
  font-weight: 500;
  font-size: 0.925rem;
  transition: color 0.3s;
}

/* Buttons */
#buttons {
  display: flex;
  justify-content: center;
  gap: 1rem;
  margin-top: 0.5rem;
}

.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  padding: 0.875rem 2rem;
  font-size: 1rem;
  font-weight: 500;
  border-radius: 10px;
  cursor: pointer;
  border: none;
  transition: all 0.2s;
  text-decoration: none;
  line-height: 1.25;
  box-shadow: 0 1px 2px 0 rgba(0, 0, 0, 0.05);
}

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

.btn-primary:hover {
  background-color: var(--primary-hover);
  transform: translateY(-1px);
  box-shadow: 0 4px 6px -1px rgba(59, 130, 246, 0.3);
}

.btn-secondary {
  background-color: white;
  color: var(--text-main);
  border: 1px solid var(--border-color);
}

.btn-secondary:hover {
  background-color: #f9fafb;
  border-color: #d1d5db;
  transform: translateY(-1px);
}

/* Footer */
.powered-by {
  font-size: 0.75rem;
  color: #9ca3af;
  margin-top: auto;
  opacity: 0.8;
}

@media (max-width: 640px) {
    #app {
        padding: 1.5rem;
        width: 95%;
    }
    
    #drop-zone {
        height: 240px;
    }
}