src/app.css

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

body {
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, sans-serif;
  background-color: #f8f9fa;
  color: #333;
  line-height: 1.4;
}

#app {
  max-width: 1400px;
  margin: 0 auto;
  padding: 2rem;
}

.header {
  background: white;
  padding: 1.5rem;
  border-radius: 8px;
  box-shadow: 0 2px 4px rgba(0, 0, 0, 0.1);
  margin-bottom: 2rem;
}

.header h1 {
  color: #2c3e50;
  margin-bottom: 1rem;
}

.controls {
  display: flex;
  gap: 1rem;
  align-items: center;
  flex-wrap: wrap;
}

.file-input {
  display: none;
}

.file-label {
  background: #3498db;
  color: white;
  padding: 0.5rem 1rem;
  border-radius: 4px;
  cursor: pointer;
  transition: background-color 0.2s;
}

.file-label:hover {
  background: #2980b9;
}

.filter-input {
  padding: 0.5rem;
  border: 1px solid #ddd;
  border-radius: 4px;
  font-size: 14px;
}

.filter-input:focus {
  outline: none;
  border-color: #3498db;
}

.stats {
  color: #666;
  font-size: 14px;
}

.thread-container {
  background: white;
  border-radius: 8px;
  box-shadow: 0 2px 4px rgba(0, 0, 0, 0.1);
  margin-bottom: 1rem;
  overflow: hidden;
}

.thread-header {
  padding: 1rem;
  background: #34495e;
  color: white;
  cursor: pointer;
  user-select: none;
  display: flex;
  justify-content: space-between;
  align-items: center;
}

.thread-header:hover {
  background: #2c3e50;
}

.thread-title {
  font-family: "Monaco", "Menlo", "Ubuntu Mono", monospace;
  font-size: 14px;
}

.toggle-indicator {
  transition: transform 0.2s;
}

.toggle-indicator.expanded {
  transform: rotate(90deg);
}

.thread-content {
  padding: 1rem;
  background: #f8f9fa;
  border-top: 1px solid #e9ecef;
}

.backtrace {
  font-family: "Monaco", "Menlo", "Ubuntu Mono", monospace;
  font-size: 12px;
  line-height: 1.3;
  white-space: pre;
  overflow-x: auto;
  background: white;
  padding: 1rem;
  border-radius: 4px;
  border: 1px solid #e9ecef;
}

.backtrace-line {
  margin: 2px 0;
  padding: 1px 0;
  cursor: default;
}

.backtrace-line.has-section {
  cursor: pointer;
}

.backtrace-line.has-section:hover {
  background-color: #f0f8ff;
}

.collapse-indicator {
  color: #3498db;
  font-size: 10px;
  margin-right: 4px;
  font-weight: bold;
  user-select: none;
}

.backtrace-line.section-collapsed .collapse-indicator {
  color: #95a5a6;
}

.backtrace-line .indent {
  display: inline-block;
}

.backtrace-line .sample-count {
  color: #e67e22;
  font-weight: bold;
}

.backtrace-line .function-name {
  color: #2c3e50;
}

.backtrace-line .address {
  color: #7f8c8d;
}

.no-threads {
  text-align: center;
  padding: 3rem;
  color: #666;
}

.loading {
  text-align: center;
  padding: 2rem;
  color: #666;
}

@media (max-width: 768px) {
  #app {
    padding: 1rem;
  }

  .controls {
    flex-direction: column;
    align-items: stretch;
  }

  .thread-header {
    padding: 0.75rem;
  }

  .backtrace {
    font-size: 11px;
  }
}