/* === User Guide modal ============================================== */
.ug-overlay {
  position: fixed;
  inset: 0;
  background: rgba(0, 0, 0, 0.6);
  backdrop-filter: blur(4px);
  display: flex;
  align-items: center;
  justify-content: center;
  z-index: 1000;
  animation: ug-fade 0.18s ease;
}

@keyframes ug-fade {
  from { opacity: 0; }
  to { opacity: 1; }
}

.ug-modal {
  width: 92vw;
  max-width: 1000px;
  height: 80vh;
  max-height: 720px;
  background: var(--bg-primary);
  color: var(--text-primary);
  border: 1px solid var(--border-primary);
  border-radius: 18px;
  box-shadow: 0 30px 80px -10px rgba(0, 0, 0, 0.5);
  display: flex;
  flex-direction: column;
  overflow: hidden;
  animation: ug-pop 0.22s cubic-bezier(0.4, 0, 0.2, 1);
}

@keyframes ug-pop {
  from { opacity: 0; transform: scale(0.96); }
  to   { opacity: 1; transform: scale(1); }
}

/* Header bar */
.ug-header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 18px 22px;
  border-bottom: 1px solid var(--border-primary);
}

.ug-title {
  display: flex;
  align-items: center;
  gap: 10px;
  font-size: 16px;
  font-weight: 700;
  letter-spacing: -0.01em;
}

.ug-title-icon {
  display: flex;
  align-items: center;
  justify-content: center;
  width: 32px;
  height: 32px;
  border-radius: 8px;
  background: #2663EB;
  color: #fff;
  flex-shrink: 0;
}

.ug-close {
  display: flex;
  align-items: center;
  justify-content: center;
  width: 32px;
  height: 32px;
  border: none;
  background: transparent;
  border-radius: 8px;
  cursor: pointer;
  color: var(--text-secondary);
  transition: background 0.15s ease, color 0.15s ease;
}

.ug-close:hover {
  background: var(--bg-secondary);
  color: var(--text-primary);
}

/* Body layout: sidebar + content */
.ug-body {
  flex: 1;
  display: grid;
  grid-template-columns: 240px 1fr;
  min-height: 0;
}

/* Sidebar */
.ug-sidebar {
  display: flex;
  flex-direction: column;
  border-right: 1px solid var(--border-primary);
  background: var(--bg-secondary);
  min-height: 0;
}

.ug-search {
  display: flex;
  align-items: center;
  gap: 8px;
  margin: 14px;
  padding: 8px 12px;
  background: var(--bg-primary);
  border: 1px solid var(--border-primary);
  border-radius: 10px;
  color: var(--text-secondary);
}

.ug-search input {
  flex: 1;
  border: none;
  outline: none;
  background: transparent;
  color: var(--text-primary);
  font-size: 13.5px;
}

.ug-search input::placeholder {
  color: var(--text-tertiary);
}

.ug-toc {
  flex: 1;
  overflow-y: auto;
  padding: 4px 10px 14px;
  display: flex;
  flex-direction: column;
  gap: 2px;
}

.ug-toc-item {
  display: flex;
  align-items: center;
  gap: 10px;
  padding: 10px 12px;
  border: none;
  background: transparent;
  border-radius: 8px;
  cursor: pointer;
  color: var(--text-secondary);
  font-size: 13.5px;
  font-weight: 500;
  text-align: left;
  transition: background 0.15s ease, color 0.15s ease;
}

.ug-toc-item span {
  flex: 1;
}

.ug-toc-arrow {
  opacity: 0;
  transition: opacity 0.15s ease, transform 0.15s ease;
}

.ug-toc-item:hover {
  background: var(--bg-primary);
  color: var(--text-primary);
}

.ug-toc-item:hover .ug-toc-arrow {
  opacity: 0.6;
}

.ug-toc-item.active {
  background: rgba(38, 99, 235, 0.1);
  color: #2663EB;
}

.ug-toc-item.active .ug-toc-arrow {
  opacity: 1;
  transform: translateX(2px);
}

.ug-empty {
  padding: 14px;
  font-size: 13px;
  color: var(--text-tertiary);
  text-align: center;
}

/* Content area */
.ug-content {
  overflow-y: auto;
  padding: 28px 36px 40px;
  font-size: 15px;
  line-height: 1.65;
  color: var(--text-primary);
  animation: ug-slide 0.2s cubic-bezier(0.4, 0, 0.2, 1);
}

@keyframes ug-slide {
  from { opacity: 0; transform: translateY(6px); }
  to   { opacity: 1; transform: translateY(0); }
}

.ug-content h1 {
  margin: 0 0 16px;
  font-size: 26px;
  font-weight: 800;
  letter-spacing: -0.02em;
  color: var(--text-primary);
}

.ug-content h2 {
  margin: 28px 0 10px;
  font-size: 18px;
  font-weight: 700;
  color: var(--text-primary);
  letter-spacing: -0.01em;
}

.ug-content h3 {
  margin: 22px 0 6px;
  font-size: 15px;
  font-weight: 700;
  color: var(--text-primary);
}

.ug-content p {
  margin: 0 0 14px;
  color: var(--text-secondary);
}

.ug-content ul, .ug-content ol {
  margin: 0 0 16px;
  padding-left: 22px;
  color: var(--text-secondary);
}

.ug-content li {
  margin-bottom: 6px;
}

.ug-content strong {
  color: var(--text-primary);
  font-weight: 600;
}

.ug-content code {
  padding: 1px 6px;
  border-radius: 4px;
  background: var(--bg-secondary);
  font-size: 0.9em;
  color: #2663EB;
  font-family: 'SF Mono', ui-monospace, monospace;
}

.ug-content a {
  color: #2663EB;
  text-decoration: none;
}

.ug-content a:hover {
  text-decoration: underline;
}

/* Mobile */
@media (max-width: 720px) {
  .ug-body {
    grid-template-columns: 1fr;
    grid-template-rows: auto 1fr;
  }
  .ug-sidebar {
    border-right: none;
    border-bottom: 1px solid var(--border-primary);
    max-height: 200px;
  }
  .ug-content {
    padding: 22px 22px 36px;
  }
}