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

body {
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, sans-serif;
  line-height: 1.6;
  color: #1a1a1a;
  background: #f5f5f5;
}

#app {
  max-width: 960px;
  margin: 0 auto;
  padding: 20px;
}

/* Header */
.header {
  display: flex;
  justify-content: space-between;
  align-items: center;
  padding: 16px 0;
  border-bottom: 2px solid #e0e0e0;
  margin-bottom: 24px;
}

.header h1 {
  font-size: 1.4rem;
  font-weight: 700;
  color: #333;
}

.header .user-info {
  font-size: 0.9rem;
  color: #666;
}

/* Join screen */
.join-screen {
  max-width: 480px;
  margin: 80px auto;
  background: white;
  padding: 40px;
  border-radius: 8px;
  box-shadow: 0 2px 8px rgba(0,0,0,0.1);
}

.join-screen h2 {
  margin-bottom: 24px;
  font-size: 1.5rem;
}

.form-group {
  margin-bottom: 16px;
}

.form-group label {
  display: block;
  margin-bottom: 4px;
  font-weight: 600;
  font-size: 0.85rem;
  color: #555;
}

.form-group input,
.form-group textarea,
.form-group select {
  width: 100%;
  padding: 8px 12px;
  border: 1px solid #ddd;
  border-radius: 4px;
  font-size: 0.95rem;
  font-family: inherit;
}

.form-group textarea {
  min-height: 120px;
  resize: vertical;
}

button {
  padding: 8px 20px;
  border: none;
  border-radius: 4px;
  font-size: 0.9rem;
  cursor: pointer;
  font-family: inherit;
  font-weight: 600;
}

.btn-primary {
  background: #2563eb;
  color: white;
}

.btn-primary:hover {
  background: #1d4ed8;
}

.btn-secondary {
  background: #e5e7eb;
  color: #333;
}

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

.btn-danger {
  background: #dc2626;
  color: white;
}

.btn-danger:hover {
  background: #b91c1c;
}

.btn-small {
  padding: 4px 12px;
  font-size: 0.8rem;
}

/* Spec list */
.spec-list {
  margin-top: 20px;
}

.spec-list h3 {
  margin-bottom: 12px;
  font-size: 1rem;
  color: #666;
}

.spec-card {
  background: white;
  padding: 16px;
  border-radius: 6px;
  margin-bottom: 8px;
  box-shadow: 0 1px 3px rgba(0,0,0,0.08);
  cursor: pointer;
  transition: box-shadow 0.15s;
}

.spec-card:hover {
  box-shadow: 0 2px 8px rgba(0,0,0,0.15);
}

.spec-card h4 {
  font-size: 1rem;
  margin-bottom: 4px;
}

.spec-card .meta {
  font-size: 0.8rem;
  color: #888;
}

.status-badge {
  display: inline-block;
  padding: 2px 8px;
  border-radius: 12px;
  font-size: 0.75rem;
  font-weight: 600;
}

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

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

/* Spec view */
.spec-view {
  background: white;
  border-radius: 8px;
  box-shadow: 0 2px 8px rgba(0,0,0,0.1);
  overflow: hidden;
}

.spec-header {
  padding: 20px;
  border-bottom: 1px solid #e5e7eb;
}

.spec-header h2 {
  font-size: 1.3rem;
  margin-bottom: 8px;
}

.spec-header .participants {
  font-size: 0.85rem;
  color: #666;
}

.spec-header .version-info {
  font-size: 0.85rem;
  color: #888;
  margin-top: 4px;
}

/* Tabs */
.tabs {
  display: flex;
  border-bottom: 1px solid #e5e7eb;
  background: #fafafa;
}

.tab {
  padding: 10px 20px;
  cursor: pointer;
  font-size: 0.9rem;
  border-bottom: 2px solid transparent;
  color: #666;
}

.tab:hover {
  color: #333;
}

.tab.active {
  color: #2563eb;
  border-bottom-color: #2563eb;
  font-weight: 600;
}

/* Content area */
.content-area {
  padding: 20px;
}

.markdown-content {
  line-height: 1.8;
}

.markdown-content h1,
.markdown-content h2,
.markdown-content h3 {
  margin-top: 24px;
  margin-bottom: 8px;
}

.markdown-content h2 {
  font-size: 1.3rem;
  padding-bottom: 4px;
  border-bottom: 1px solid #eee;
}

.markdown-content p {
  margin-bottom: 12px;
}

.markdown-content ul, .markdown-content ol {
  margin-bottom: 12px;
  padding-left: 24px;
}

.markdown-content code {
  background: #f1f5f9;
  padding: 2px 6px;
  border-radius: 3px;
  font-size: 0.9em;
}

.markdown-content pre {
  background: #1e293b;
  color: #e2e8f0;
  padding: 16px;
  border-radius: 6px;
  overflow-x: auto;
  margin-bottom: 16px;
}

.markdown-content pre code {
  background: transparent;
  padding: 0;
  color: inherit;
}

.markdown-content table {
  width: 100%;
  border-collapse: collapse;
  margin-bottom: 16px;
  font-size: 0.9em;
}

.markdown-content th,
.markdown-content td {
  border: 1px solid #d1d5db;
  padding: 8px 12px;
  text-align: left;
}

.markdown-content th {
  background: #f1f5f9;
  font-weight: 600;
}

.markdown-content tr:nth-child(even) {
  background: #f9fafb;
}

.markdown-content blockquote {
  border-left: 3px solid #d1d5db;
  padding: 4px 16px;
  margin: 0 0 16px 0;
  color: #555;
  background: #f9fafb;
}

.markdown-content hr {
  border: none;
  border-top: 1px solid #e5e7eb;
  margin: 20px 0;
}

/* Edit mode */
.edit-area {
  padding: 20px;
}

.edit-area textarea {
  width: 100%;
  min-height: 400px;
  padding: 12px;
  font-family: "SF Mono", "Consolas", monospace;
  font-size: 0.9rem;
  border: 1px solid #ddd;
  border-radius: 4px;
  resize: vertical;
  line-height: 1.6;
}

.edit-controls {
  display: flex;
  gap: 8px;
  margin-top: 12px;
  align-items: center;
}

.edit-controls input {
  flex: 1;
  padding: 8px 12px;
  border: 1px solid #ddd;
  border-radius: 4px;
  font-size: 0.9rem;
}

/* Discussions */
.discussion-list {
  padding: 0;
}

.discussion-item {
  padding: 16px 20px;
  border-bottom: 1px solid #f0f0f0;
  cursor: pointer;
}

.discussion-item:hover {
  background: #fafafa;
}

.discussion-item h4 {
  font-size: 0.95rem;
  margin-bottom: 4px;
}

.discussion-item .disc-meta {
  font-size: 0.8rem;
  color: #888;
}

.discussion-thread {
  padding: 20px;
}

.discussion-thread h3 {
  margin-bottom: 4px;
}

.discussion-thread .thread-meta {
  font-size: 0.85rem;
  color: #888;
  margin-bottom: 16px;
}

.reply-item {
  padding: 16px 20px;
  margin-bottom: 16px;
  background: #f9fafb;
  border-radius: 6px;
  border-left: 4px solid #ddd;
}

.reply-item .reply-author {
  font-weight: 600;
  font-size: 0.85rem;
}

.reply-item .reply-time {
  font-size: 0.75rem;
  color: #999;
  margin-left: 8px;
}

.reply-item .reply-body {
  margin-top: 4px;
  font-size: 0.9rem;
}

.resolution-box {
  padding: 12px 16px;
  background: #dcfce7;
  border-radius: 6px;
  margin-top: 12px;
  border-left: 3px solid #22c55e;
  font-size: 0.9rem;
}

/* Version list */
.version-item {
  display: flex;
  justify-content: space-between;
  align-items: center;
  padding: 12px 20px;
  border-bottom: 1px solid #f0f0f0;
}

.version-item .version-num {
  font-weight: 700;
  color: #2563eb;
  min-width: 40px;
}

.version-item .version-info {
  flex: 1;
  margin-left: 12px;
}

.version-item .version-author {
  font-weight: 600;
  font-size: 0.9rem;
}

.version-item .version-msg {
  font-size: 0.85rem;
  color: #666;
}

.version-item .version-time {
  font-size: 0.8rem;
  color: #999;
}

/* Diff view — GitHub-style */
.diff-view {
  padding: 20px;
}

.diff-table {
  width: 100%;
  border-collapse: collapse;
  font-family: "SF Mono", "Consolas", "Monaco", monospace;
  font-size: 0.82rem;
  line-height: 1.5;
  border: 1px solid #d1d5db;
  border-radius: 6px;
  overflow: hidden;
}

.diff-table td {
  padding: 1px 12px;
  white-space: pre-wrap;
  word-break: break-word;
  vertical-align: top;
  border: none;
}

.diff-line-num {
  width: 1%;
  min-width: 40px;
  padding: 1px 8px;
  text-align: right;
  color: #9ca3af;
  background: #f9fafb;
  user-select: none;
  border-right: 1px solid #e5e7eb;
  font-size: 0.75rem;
}

.diff-line-add {
  background: #dcfce7;
}

.diff-line-add .diff-line-num {
  background: #bbf7d0;
  color: #166534;
}

.diff-line-remove {
  background: #fee2e2;
}

.diff-line-remove .diff-line-num {
  background: #fecaca;
  color: #991b1b;
}

.diff-line-hunk {
  background: #eff6ff;
  color: #1e40af;
  font-weight: 600;
}

.diff-line-hunk td {
  padding: 6px 12px;
}

.diff-line-hunk .diff-line-num {
  background: #dbeafe;
}

.diff-line-header {
  background: #f1f5f9;
  color: #475569;
  font-weight: 700;
}

.diff-line-header td {
  padding: 8px 12px;
  border-bottom: 1px solid #e5e7eb;
}

/* Toast / notifications */
.toast-container {
  position: fixed;
  bottom: 20px;
  right: 20px;
  z-index: 1000;
}

.toast {
  background: #333;
  color: white;
  padding: 12px 20px;
  border-radius: 6px;
  margin-top: 8px;
  font-size: 0.85rem;
  animation: slideIn 0.3s ease;
  max-width: 360px;
}

@keyframes slideIn {
  from { transform: translateX(100%); opacity: 0; }
  to { transform: translateX(0); opacity: 1; }
}

/* Finalized banner */
.finalized-banner {
  background: #dcfce7;
  border: 1px solid #bbf7d0;
  color: #166534;
  padding: 12px 20px;
  text-align: center;
  font-weight: 600;
}

/* Back link */
.back-link {
  display: inline-block;
  margin-bottom: 16px;
  color: #2563eb;
  cursor: pointer;
  font-size: 0.9rem;
}

.back-link:hover {
  text-decoration: underline;
}

/* Inline forms */
.inline-form {
  margin-top: 16px;
  padding: 16px;
  background: #f9fafb;
  border-radius: 6px;
}

.inline-form h4 {
  margin-bottom: 12px;
}

/* Loading */
.loading {
  text-align: center;
  padding: 40px;
  color: #999;
}

/* Error */
.error-msg {
  color: #dc2626;
  background: #fef2f2;
  padding: 8px 12px;
  border-radius: 4px;
  margin: 8px 0;
  font-size: 0.85rem;
}

/* Actions bar */
.actions-bar {
  display: flex;
  gap: 8px;
  padding: 12px 20px;
  border-bottom: 1px solid #e5e7eb;
  background: #fafafa;
}