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

body {
  font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, Oxygen, Ubuntu, Cantarell, sans-serif;
  background: #f8f9fc;
  min-height: 100vh;
  color: #1a1a1a;
}

.app {
  max-width: 800px;
  margin: 0 auto;
  padding: 20px;
}

.header {
  text-align: center;
  color: #1a1a1a;
  margin-bottom: 48px;
  padding: 48px 20px 24px;
  background: white;
  border-bottom: 1px solid #e8eaf0;
}

.header-content h1 {
  font-size: 3rem;
  margin-bottom: 12px;
  font-weight: 700;
  color: #1a1a1a;
  letter-spacing: -0.02em;
}

.tagline {
  font-size: 1.15rem;
  color: #6c757d;
  margin-bottom: 24px;
  font-weight: 400;
}

.header-links {
  display: flex;
  gap: 20px;
  justify-content: center;
  margin-top: 20px;
}

.header-links a {
  color: #5568d3;
  text-decoration: none;
  font-size: 0.95rem;
  transition: color 0.2s;
  display: inline-flex;
  align-items: center;
  gap: 6px;
  font-weight: 500;
}

.header-links a:hover {
  color: #667eea;
}

.github-icon {
  display: inline-block;
  vertical-align: middle;
}

.main {
  position: relative;
  min-height: 500px;
}

.step-container {
  background: white;
  border-radius: 12px;
  padding: 48px;
  box-shadow: 0 1px 3px rgba(0, 0, 0, 0.06), 0 2px 8px rgba(0, 0, 0, 0.04);
  border: 1px solid #e8eaf0;
  animation: fadeIn 0.3s ease-out;
}

@keyframes fadeIn {
  from {
    opacity: 0;
    transform: translateY(20px);
  }
  to {
    opacity: 1;
    transform: translateY(0);
  }
}

.step-container h2 {
  color: #1a1a1a;
  margin-bottom: 32px;
  font-size: 1.8rem;
  text-align: center;
  font-weight: 700;
  letter-spacing: -0.01em;
}

.button-grid {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 16px;
  margin-bottom: 24px;
}

.button-grid-three {
  grid-template-columns: repeat(3, 1fr);
}

.action-button {
  background: #fafbfc;
  border: 2px solid #e8eaf0;
  padding: 32px 24px;
  border-radius: 10px;
  cursor: pointer;
  transition: all 0.2s;
  text-align: left;
  display: flex;
  flex-direction: column;
  gap: 8px;
}

.action-button:hover {
  border-color: #5568d3;
  background: white;
  transform: translateY(-2px);
  box-shadow: 0 4px 12px rgba(85, 104, 211, 0.12);
}

.button-title {
  font-size: 1.4rem;
  font-weight: 700;
  color: #1a1a1a;
}

.button-description {
  font-size: 0.95rem;
  color: #6c757d;
  line-height: 1.5;
}

.form-container {
  max-width: 500px;
  margin: 0 auto;
}

.form-group {
  margin-bottom: 24px;
}

.form-group label {
  display: block;
  font-weight: 600;
  color: #1a1a1a;
  margin-bottom: 8px;
  font-size: 0.95rem;
}

.help-text {
  margin-top: 8px;
  font-size: 0.85rem;
  color: #6c757d;
}

input[type="text"] {
  width: 100%;
  padding: 12px 16px;
  border: 2px solid #e8eaf0;
  border-radius: 8px;
  font-size: 1rem;
  transition: all 0.2s;
  background: white;
}

input[type="text"]:focus {
  outline: none;
  border-color: #5568d3;
  box-shadow: 0 0 0 3px rgba(85, 104, 211, 0.08);
}

input[type="text"]:disabled {
  background: #f5f5f5;
  cursor: not-allowed;
}

.topic-list {
  margin-top: 12px;
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
}

.topic-item {
  background: white;
  color: #1a1a1a;
  border: 2px solid #e8eaf0;
  padding: 8px 12px;
  border-radius: 6px;
  font-size: 0.9rem;
  font-weight: 500;
  cursor: pointer;
  transition: all 0.2s;
  margin: 0;
}

.topic-item:hover {
  border-color: #5568d3;
  background: #fafbfc;
  transform: none;
  box-shadow: none;
}

.topic-item .peer-count {
  background: transparent;
  color: #5568d3;
  padding: 0;
  font-weight: 600;
  font-size: 0.85rem;
}

.button-row {
  display: flex;
  justify-content: space-between;
  align-items: center;
  margin-top: 32px;
}

.back-button {
  background: transparent;
  color: #6c757d;
  border: none;
  padding: 8px 16px;
  font-size: 0.95rem;
  cursor: pointer;
  transition: all 0.2s;
  margin: 0;
}

.back-button:hover {
  color: #5568d3;
  background: transparent;
  transform: none;
  box-shadow: none;
}

.primary-button {
  background: #5568d3;
  color: white;
  border: none;
  padding: 12px 32px;
  border-radius: 8px;
  font-size: 1rem;
  font-weight: 600;
  cursor: pointer;
  transition: all 0.2s;
  margin: 0;
}

.primary-button:hover:not(:disabled) {
  background: #4556be;
  transform: translateY(-1px);
  box-shadow: 0 4px 12px rgba(85, 104, 211, 0.25);
}

.primary-button:disabled {
  background: #d1d5db;
  cursor: not-allowed;
  transform: none;
}

.chat-container {
  background: white;
  border-radius: 12px;
  padding: 32px;
  box-shadow: 0 1px 3px rgba(0, 0, 0, 0.06), 0 2px 8px rgba(0, 0, 0, 0.04);
  border: 1px solid #e8eaf0;
  animation: fadeIn 0.3s ease-out;
  max-width: 700px;
  margin: 0 auto;
}

.chat-header {
  display: flex;
  justify-content: space-between;
  align-items: flex-start;
  margin-bottom: 24px;
  padding-bottom: 20px;
  border-bottom: 1px solid #e8eaf0;
}

.chat-header h2 {
  color: #1a1a1a;
  font-size: 1.6rem;
  margin-bottom: 8px;
  font-weight: 700;
  letter-spacing: -0.01em;
}

.connection-details {
  color: #6c757d;
  font-size: 0.9rem;
}

.disconnect-button {
  background: #dc3545;
  color: white;
  border: none;
  padding: 10px 20px;
  border-radius: 6px;
  font-size: 0.9rem;
  font-weight: 600;
  cursor: pointer;
  transition: all 0.2s;
  margin: 0;
}

.disconnect-button:hover {
  background: #c82333;
  transform: translateY(-1px);
  box-shadow: 0 4px 12px rgba(220, 53, 69, 0.3);
}

.messages {
  background: #fafbfc;
  border-radius: 12px;
  padding: 20px;
  min-height: 400px;
  max-height: 400px;
  overflow-y: auto;
  margin-bottom: 20px;
  border: 1px solid #e8eaf0;
}

.messages::-webkit-scrollbar {
  width: 8px;
}

.messages::-webkit-scrollbar-track {
  background: #e8eaf0;
  border-radius: 4px;
}

.messages::-webkit-scrollbar-thumb {
  background: #5568d3;
  border-radius: 4px;
}

.empty {
  text-align: center;
  color: #6c757d;
  padding: 40px 20px;
  font-size: 0.95rem;
}

.message {
  margin-bottom: 16px;
  animation: slideIn 0.2s ease-out;
}

@keyframes slideIn {
  from {
    opacity: 0;
    transform: translateY(10px);
  }
  to {
    opacity: 1;
    transform: translateY(0);
  }
}

.message-text {
  padding: 12px 16px;
  border-radius: 12px;
  max-width: 70%;
  word-wrap: break-word;
  line-height: 1.4;
}

.message.sent .message-text {
  background: #5568d3;
  color: white;
  margin-left: auto;
  border-bottom-right-radius: 4px;
}

.message.received .message-text {
  background: white;
  color: #1a1a1a;
  border: 2px solid #e8eaf0;
  border-bottom-left-radius: 4px;
}

.message-time {
  font-size: 0.75rem;
  color: #6c757d;
  margin-top: 4px;
  padding: 0 16px;
}

.message.sent .message-time {
  text-align: right;
}

.message-input {
  display: flex;
  gap: 12px;
}

.message-input input[type="text"] {
  flex: 1;
  margin-bottom: 0;
}

.message-input button {
  margin: 0;
  padding: 12px 24px;
  background: #5568d3;
  color: white;
  border: none;
  border-radius: 8px;
  font-weight: 600;
  cursor: pointer;
  transition: all 0.2s;
}

.message-input .file-button {
  padding: 12px 16px;
  font-size: 1.2rem;
}

.message-input button:hover:not(:disabled) {
  background: #4556be;
  transform: translateY(-1px);
  box-shadow: 0 4px 12px rgba(85, 104, 211, 0.25);
}

.message-input button:disabled {
  background: #d1d5db;
  cursor: not-allowed;
  transform: none;
}

.message-file {
  display: flex;
  align-items: center;
  gap: 12px;
  padding: 12px 16px;
  border-radius: 12px;
  background: inherit;
  width: 100%;
  max-width: 400px;
}

.message.sent .message-file {
  background: rgba(255, 255, 255, 0.2);
  margin-left: auto;
}

.message.received .message-file {
  background: white;
  border: 2px solid #e8eaf0;
}

.file-icon {
  font-size: 1.5rem;
  flex-shrink: 0;
}

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

.file-name {
  font-weight: 600;
  font-size: 0.9rem;
  overflow: hidden;
  text-overflow: ellipsis;
  white-space: nowrap;
}

.message.sent .file-name {
  color: white;
}

.message.received .file-name {
  color: #1a1a1a;
}

.file-size {
  font-size: 0.75rem;
  opacity: 0.8;
  margin-top: 2px;
}

.message.sent .file-size {
  color: white;
}

.message.received .file-size {
  color: #6c757d;
}

.file-download {
  padding: 6px 12px;
  font-size: 0.85rem;
  background: rgba(255, 255, 255, 0.9);
  color: #5568d3;
  border: none;
  border-radius: 6px;
  font-weight: 600;
  cursor: pointer;
  transition: all 0.2s;
  flex-shrink: 0;
}

.message.sent .file-download {
  background: rgba(255, 255, 255, 0.3);
  color: white;
}

.file-download:hover {
  background: white;
  transform: scale(1.05);
}

.file-upload-progress {
  background: white;
  border: 2px solid #5568d3;
  border-radius: 8px;
  padding: 16px;
  margin-bottom: 16px;
}

.file-upload-header {
  display: flex;
  justify-content: space-between;
  align-items: center;
  margin-bottom: 12px;
}

.file-upload-name {
  font-weight: 600;
  color: #1a1a1a;
  font-size: 0.9rem;
}

.file-upload-cancel {
  background: #dc3545;
  color: white;
  border: none;
  width: 24px;
  height: 24px;
  border-radius: 50%;
  font-size: 1.2rem;
  line-height: 1;
  cursor: pointer;
  transition: all 0.2s;
  display: flex;
  align-items: center;
  justify-content: center;
  padding: 0;
}

.file-upload-cancel:hover {
  background: #c82333;
  transform: scale(1.1);
}

.progress-bar {
  background: #e8eaf0;
  border-radius: 8px;
  height: 24px;
  overflow: hidden;
  position: relative;
}

.progress-bar-fill {
  background: #5568d3;
  height: 100%;
  transition: width 0.3s ease;
  display: flex;
  align-items: center;
  justify-content: center;
  position: relative;
}

.progress-text {
  color: white;
  font-size: 0.75rem;
  font-weight: 600;
  text-shadow: 0 1px 2px rgba(0, 0, 0, 0.2);
}

.logs {
  margin-top: 24px;
  border-top: 1px solid #e8eaf0;
  padding-top: 20px;
}

.logs summary {
  cursor: pointer;
  font-weight: 600;
  color: #5568d3;
  font-size: 0.95rem;
  margin-bottom: 12px;
}

.log-entries {
  background: #1e1e1e;
  color: #d4d4d4;
  padding: 16px;
  border-radius: 8px;
  font-family: 'Courier New', monospace;
  font-size: 0.85rem;
  max-height: 200px;
  overflow-y: auto;
  margin-top: 12px;
}

.log-entry {
  margin-bottom: 4px;
  line-height: 1.5;
}

.log-entry.info {
  color: #4ec9b0;
}

.log-entry.success {
  color: #6a9955;
}

.log-entry.error {
  color: #f48771;
}

.peer-id-badge {
  position: fixed;
  bottom: 20px;
  right: 20px;
  background: white;
  color: #5568d3;
  padding: 10px 16px;
  border-radius: 8px;
  font-size: 0.85rem;
  font-weight: 600;
  box-shadow: 0 1px 3px rgba(0, 0, 0, 0.06), 0 2px 8px rgba(0, 0, 0, 0.04);
  border: 1px solid #e8eaf0;
}

.scanner-container {
  margin-top: 24px;
  text-align: center;
  animation: fadeIn 0.3s ease-out;
}

.scanner-video {
  width: 100%;
  max-width: 400px;
  height: 300px;
  border-radius: 12px;
  background: #1e1e1e;
  margin-bottom: 16px;
  object-fit: cover;
}

.qr-code-container {
  text-align: center;
  padding: 24px;
  background: #fafbfc;
  border-radius: 12px;
  margin-bottom: 20px;
  border: 1px solid #e8eaf0;
}

.qr-label {
  font-size: 0.95rem;
  color: #5568d3;
  font-weight: 600;
  margin-bottom: 12px;
}

.qr-code {
  display: block;
  margin: 0 auto 12px;
  border-radius: 8px;
  background: white;
  padding: 12px;
  box-shadow: 0 1px 3px rgba(0, 0, 0, 0.06);
  border: 1px solid #e8eaf0;
}

.connection-id-display {
  font-family: 'Courier New', monospace;
  font-size: 0.9rem;
  color: #1a1a1a;
  background: white;
  padding: 8px 16px;
  border-radius: 6px;
  display: inline-block;
  font-weight: 600;
  border: 1px solid #e8eaf0;
}

.footer {
  text-align: center;
  padding: 40px 20px 30px;
  margin-top: 40px;
  border-top: 1px solid #e8eaf0;
}

.footer a {
  color: #6c757d;
  text-decoration: none;
  font-size: 0.9rem;
  transition: color 0.2s;
}

.footer a:hover {
  color: #5568d3;
}

@media (max-width: 768px) {
  .app {
    padding: 10px;
  }

  .header {
    padding: 20px 10px 10px;
  }

  .header-content h1 {
    font-size: 2rem;
  }

  .tagline {
    font-size: 1rem;
  }

  .step-container {
    padding: 32px 24px;
  }

  .button-grid,
  .button-grid-three {
    grid-template-columns: 1fr;
  }

  .chat-container {
    padding: 24px 16px;
  }

  .messages {
    min-height: 300px;
    max-height: 300px;
  }

  .message-text {
    max-width: 85%;
  }

  .peer-id-badge {
    bottom: 10px;
    right: 10px;
    font-size: 0.75rem;
    padding: 8px 12px;
  }
}

@media (max-width: 480px) {
  .header-content h1 {
    font-size: 1.6rem;
  }

  .step-container h2 {
    font-size: 1.4rem;
  }

  .button-title {
    font-size: 1.2rem;
  }

  .chat-header {
    flex-direction: column;
    gap: 16px;
  }

  .disconnect-button {
    width: 100%;
  }
}

/* Topics List Modal */
.modal-overlay {
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  bottom: 0;
  background: rgba(0, 0, 0, 0.5);
  display: flex;
  align-items: center;
  justify-content: center;
  z-index: 1000;
  animation: fadeIn 0.2s ease-out;
}

.modal-content {
  background: white;
  border-radius: 12px;
  max-width: 600px;
  width: 90%;
  max-height: 80vh;
  display: flex;
  flex-direction: column;
  box-shadow: 0 10px 40px rgba(0, 0, 0, 0.15);
  animation: slideUp 0.3s ease-out;
}

@keyframes slideUp {
  from {
    opacity: 0;
    transform: translateY(30px);
  }
  to {
    opacity: 1;
    transform: translateY(0);
  }
}

.modal-header {
  padding: 24px 32px;
  border-bottom: 1px solid #e8eaf0;
  display: flex;
  align-items: center;
  justify-content: space-between;
}

.modal-header h2 {
  margin: 0;
  font-size: 1.5rem;
  color: #1a1a1a;
}

.close-button {
  background: none;
  border: none;
  font-size: 2rem;
  color: #6c757d;
  cursor: pointer;
  padding: 0;
  width: 36px;
  height: 36px;
  display: flex;
  align-items: center;
  justify-content: center;
  border-radius: 6px;
  transition: all 0.2s;
}

.close-button:hover {
  background: #f8f9fc;
  color: #1a1a1a;
}

.modal-body {
  padding: 24px 32px;
  overflow-y: auto;
  flex: 1;
}

.modal-footer {
  padding: 20px 32px;
  border-top: 1px solid #e8eaf0;
  display: flex;
  gap: 12px;
  justify-content: flex-end;
}

.topics-list {
  display: flex;
  flex-direction: column;
  gap: 12px;
}

.topic-item {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 16px 20px;
  background: #f8f9fc;
  border: 1px solid #e8eaf0;
  border-radius: 8px;
  transition: all 0.2s;
}

.topic-item:hover {
  background: #f0f2f8;
  border-color: #d0d5dd;
}

.topic-name {
  font-weight: 500;
  color: #1a1a1a;
  font-size: 1rem;
  word-break: break-all;
}

.topic-count {
  font-size: 0.9rem;
  color: #6c757d;
  background: white;
  padding: 4px 12px;
  border-radius: 12px;
  font-weight: 500;
  white-space: nowrap;
}

.pagination {
  display: flex;
  align-items: center;
  justify-content: space-between;
  margin-top: 24px;
  padding-top: 20px;
  border-top: 1px solid #e8eaf0;
}

.pagination-button {
  padding: 10px 20px;
  border: 1px solid #e8eaf0;
  background: white;
  color: #1a1a1a;
  border-radius: 8px;
  font-size: 0.95rem;
  cursor: pointer;
  transition: all 0.2s;
  font-weight: 500;
}

.pagination-button:hover:not(:disabled) {
  background: #f8f9fc;
  border-color: #5568d3;
  color: #5568d3;
}

.pagination-button:disabled {
  opacity: 0.4;
  cursor: not-allowed;
}

.pagination-info {
  font-size: 0.9rem;
  color: #6c757d;
}

.loading-message, .empty-message, .error-message {
  text-align: center;
  padding: 40px 20px;
  color: #6c757d;
  font-size: 1rem;
}

.error-message {
  color: #dc3545;
  background: #ffe8eb;
  border: 1px solid #ffccd2;
  border-radius: 8px;
  padding: 16px;
}

.view-topics-button {
  position: fixed;
  bottom: 80px;
  right: 20px;
  padding: 14px 24px;
  background: #5568d3;
  color: white;
  border: none;
  border-radius: 8px;
  font-size: 1rem;
  font-weight: 500;
  cursor: pointer;
  box-shadow: 0 4px 12px rgba(85, 104, 211, 0.3);
  transition: all 0.2s;
  z-index: 100;
}

.view-topics-button:hover {
  background: #667eea;
  transform: translateY(-2px);
  box-shadow: 0 6px 16px rgba(85, 104, 211, 0.4);
}

/* Topic cards grid for discovery */
.topic-card-hover {
  padding: 25px;
  background: white;
  border-radius: 12px;
  border: 2px solid #e0e0e0;
  text-align: center;
  cursor: pointer;
  transition: all 0.3s ease;
  box-shadow: 0 2px 4px rgba(0,0,0,0.05);
}

.topic-card-hover:hover {
  border-color: #667eea;
  background: #fafbfc;
  transform: translateY(-3px);
  box-shadow: 0 6px 16px rgba(102, 126, 234, 0.2);
}