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

body {
  font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, sans-serif;
  background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
  min-height: 100vh;
  display: flex;
  justify-content: center;
  align-items: center;
  padding: 20px;
}

#app {
  width: 100%;
  max-width: 500px;
}

/* Sender Layout */
.sender-container {
  background: white;
  border-radius: 16px;
  box-shadow: 0 20px 60px rgba(0,0,0,0.3);
  padding: 40px;
}

.sender-container h1 {
  color: #2563eb;
  font-size: 2em;
  margin-bottom: 10px;
}

.sender-container .subtitle {
  color: #6b7280;
  margin-bottom: 30px;
  font-size: 0.95em;
}

/* Receiver Layout */
.receiver-container {
  background: white;
  border-radius: 16px;
  box-shadow: 0 20px 60px rgba(0,0,0,0.3);
  padding: 40px;
  text-align: center;
}

.receiver-container h1 {
  color: #2563eb;
  font-size: 2em;
  margin-bottom: 10px;
}

.receiver-container .subtitle {
  color: #6b7280;
  margin-bottom: 30px;
}

/* Buttons */
.btn {
  padding: 12px 24px;
  border: none;
  border-radius: 8px;
  font-size: 1em;
  font-weight: 600;
  cursor: pointer;
  transition: all 0.3s ease;
}

.btn-primary {
  background: linear-gradient(135deg, #2563eb, #1d4ed8);
  color: white;
  box-shadow: 0 4px 12px rgba(37, 99, 235, 0.3);
}

.btn-primary:hover {
  transform: translateY(-2px);
  box-shadow: 0 6px 16px rgba(37, 99, 235, 0.4);
}

.btn-secondary {
  background: #e5e7eb;
  color: #1f2937;
}

.btn-secondary:hover {
  background: #d1d5db;
}

/* File input */
#fileInput {
  display: none;
}

/* Files table */
.files-table {
  width: 100%;
  margin-top: 30px;
  border-collapse: collapse;
}

.files-table thead {
  background: #f3f4f6;
}

.files-table th {
  padding: 12px;
  text-align: left;
  color: #374151;
  font-weight: 600;
  border-bottom: 2px solid #e5e7eb;
}

.files-table td {
  padding: 12px;
  border-bottom: 1px solid #e5e7eb;
  color: #6b7280;
}

.file-name {
  color: #1f2937;
  font-weight: 500;
}

.file-size {
  font-size: 0.9em;
}

.file-status {
  display: inline-block;
  padding: 4px 12px;
  border-radius: 20px;
  font-size: 0.85em;
  font-weight: 600;
}

.status-pending {
  background: #fef3c7;
  color: #92400e;
}

.status-shared {
  background: #dbeafe;
  color: #1e40af;
}

.status-transferring {
  background: #dbeafe;
  color: #1e40af;
}

.status-sent {
  background: #d1fae5;
  color: #065f46;
}

.status-completed {
  background: #dcfce7;
  color: #166534;
}

/* Modal QR */
.modal {
  display: none;
  position: fixed;
  top: 0;
  left: 0;
  width: 100%;
  height: 100%;
  background: rgba(0,0,0,0.5);
  z-index: 1000;
  justify-content: center;
  align-items: center;
}

.modal.show {
  display: flex;
}

.modal-content {
  background: white;
  border-radius: 16px;
  padding: 40px;
  max-width: 400px;
  width: 90%;
  box-shadow: 0 20px 60px rgba(0,0,0,0.3);
  position: relative;
}

.modal-close {
  position: absolute;
  top: 16px;
  right: 16px;
  background: none;
  border: none;
  font-size: 24px;
  color: #6b7280;
  cursor: pointer;
}

.modal-close:hover {
  color: #1f2937;
}

.modal h2 {
  color: #1f2937;
  margin-bottom: 20px;
  font-size: 1.3em;
}

#qrContainer {
  margin: 20px 0;
  text-align: center;
}

.file-info-modal {
  background: #f3f4f6;
  border-radius: 8px;
  padding: 16px;
  margin: 20px 0;
}

.file-info-modal p {
  margin: 8px 0;
  font-size: 0.9em;
  color: #6b7280;
}

.file-info-modal strong {
  color: #1f2937;
}

#transferProgress {
  display: none;
  margin: 20px 0;
}

#progressBar {
  width: 100%;
  height: 8px;
  background: #e5e7eb;
  border-radius: 4px;
  overflow: hidden;
  margin: 12px 0;
}

#progressFill {
  height: 100%;
  background: linear-gradient(90deg, #2563eb, #667eea);
  width: 0%;
  transition: width 0.2s ease;
}

#progressText {
  font-size: 0.85em;
  color: #6b7280;
  text-align: center;
}

/* Receiver Status */
#receiverStatus {
  font-size: 1em;
  color: #374151;
  min-height: 24px;
  margin: 20px 0;
}

#fileInfoReceiver {
  background: #f3f4f6;
  border-radius: 12px;
  padding: 20px;
  margin: 20px 0;
  display: none;
  border-left: 4px solid #2563eb;
  text-align: left;
}

.receiver-file-name {
  font-weight: 600;
  font-size: 1.1em;
  color: #1f2937;
  margin-bottom: 8px;
}

.receiver-file-detail {
  color: #6b7280;
  font-size: 0.9em;
  margin: 4px 0;
}

#progressContainerReceiver {
  display: none;
  margin: 20px 0;
}

#downloadBtn {
  display: none;
  padding: 14px 32px;
  background: linear-gradient(135deg, #16a34a, #15803d);
  color: white;
  border: none;
  border-radius: 8px;
  font-size: 1em;
  font-weight: 600;
  cursor: pointer;
  margin-top: 20px;
  transition: all 0.3s ease;
  box-shadow: 0 4px 12px rgba(22, 163, 74, 0.3);
}

#downloadBtn:hover {
  transform: translateY(-2px);
  box-shadow: 0 6px 16px rgba(22, 163, 74, 0.4);
}

/* Spinner */
.spinner {
  display: inline-block;
  width: 12px;
  height: 12px;
  border: 2px solid #e5e7eb;
  border-top-color: #2563eb;
  border-radius: 50%;
  animation: spin 0.6s linear infinite;
  margin-right: 8px;
}

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

/* Status messages */
.error {
  background: #fee2e2;
  color: #dc2626;
  padding: 12px 16px;
  border-radius: 8px;
  margin: 16px 0;
  border-left: 4px solid #dc2626;
}

.success {
  background: #dcfce7;
  color: #16a34a;
  padding: 12px 16px;
  border-radius: 8px;
  margin: 16px 0;
  border-left: 4px solid #16a34a;
}

/* Empty state */
.empty-state {
  text-align: center;
  padding: 40px 20px;
  color: #6b7280;
}

.empty-state p {
  margin: 8px 0;
}

/* Responsive */
@media (max-width: 600px) {
  .sender-container,
  .receiver-container {
    padding: 30px 20px;
  }

  .files-table th,
  .files-table td {
    padding: 8px;
    font-size: 0.9em;
  }

  .btn {
    padding: 10px 16px;
    font-size: 0.95em;
  }
}