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

:root {
  --bg-primary: #ffffff;
  --bg-secondary: #f5f5f5;
  --bg-toolbar: #f0f0f0;
  --text-primary: #1e1e1e;
  --text-secondary: #666666;
  --border-color: #d4d4d4;
  --accent-color: #007acc;
  --hover-bg: #e8e8e8;

  --diff-removed-bg: #ffeef0;
  --diff-removed-line: #fdb8c0;
  --diff-added-bg: #e6ffed;
  --diff-added-line: #acf2bd;
}

[data-theme="dark"] {
  --bg-primary: #1e1e1e;
  --bg-secondary: #252526;
  --bg-toolbar: #2d2d2d;
  --text-primary: #cccccc;
  --text-secondary: #999999;
  --border-color: #3c3c3c;
  --accent-color: #4fc1ff;
  --hover-bg: #383838;

  --diff-removed-bg: #3d1f1f;
  --diff-removed-line: #8b2e2e;
  --diff-added-bg: #1f3d1f;
  --diff-added-line: #2e8b2e;
}

html,
body {
  height: 100%;
  font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, sans-serif;
  background: var(--bg-primary);
  color: var(--text-primary);
  overflow: hidden;
}

body {
  display: flex;
  flex-direction: column;
}

.toolbar {
  display: flex;
  align-items: center;
  justify-content: space-between;
  height: 48px;
  padding: 0 16px;
  background: var(--bg-toolbar);
  border-bottom: 1px solid var(--border-color);
  flex-shrink: 0;
}

.toolbar-left {
  display: flex;
  align-items: center;
}

.logo {
  font-size: 16px;
  font-weight: 600;
  color: var(--text-primary);
  letter-spacing: -0.3px;
}

.toolbar-right {
  display: flex;
  align-items: center;
  gap: 16px;
}

.control-group {
  display: flex;
  align-items: center;
  gap: 6px;
  font-size: 13px;
  color: var(--text-secondary);
}

.control-group label {
  cursor: pointer;
  display: flex;
  align-items: center;
  gap: 4px;
  white-space: nowrap;
}

#lang-select {
  padding: 4px 8px;
  border: 1px solid var(--border-color);
  border-radius: 4px;
  background: var(--bg-primary);
  color: var(--text-primary);
  font-size: 13px;
  outline: none;
  cursor: pointer;
}

#lang-select:focus {
  border-color: var(--accent-color);
}

#auto-detect {
  cursor: pointer;
  accent-color: var(--accent-color);
}

.toolbar-btn {
  background: none;
  border: 1px solid var(--border-color);
  border-radius: 4px;
  padding: 4px 8px;
  cursor: pointer;
  font-size: 13px;
  line-height: 1.4;
  display: flex;
  align-items: center;
  color: var(--text-primary);
  transition: background 0.15s;
}

.toolbar-btn:hover {
  background: var(--hover-bg);
}

[data-theme="light"] .icon-dark {
  display: none;
}
[data-theme="dark"] .icon-light {
  display: none;
}

.main-container {
  display: flex;
  flex-direction: column;
  flex: 1;
  min-height: 0;
}

.panel-header {
  display: flex;
  height: 32px;
  flex-shrink: 0;
}

.panel-label {
  flex: 1;
  display: flex;
  align-items: center;
  padding: 0 16px;
  font-size: 12px;
  font-weight: 500;
  text-transform: uppercase;
  letter-spacing: 0.5px;
  color: var(--text-secondary);
  background: var(--bg-secondary);
  border-bottom: 1px solid var(--border-color);
}

.panel-label:first-child {
  border-right: 1px solid var(--border-color);
}

.mobile-tabs {
  display: none;
  height: 36px;
  flex-shrink: 0;
  background: var(--bg-secondary);
  border-bottom: 1px solid var(--border-color);
}

.mobile-tab {
  flex: 1;
  border: none;
  background: none;
  font-size: 13px;
  font-weight: 500;
  letter-spacing: 0.3px;
  text-transform: uppercase;
  color: var(--text-secondary);
  cursor: pointer;
  padding: 0 16px;
  border-bottom: 2px solid transparent;
  transition: color 0.15s, border-color 0.15s;
}

.mobile-tab.active {
  color: var(--accent-color);
  border-bottom-color: var(--accent-color);
}

@media (max-width: 768px) {
  .mobile-tabs {
    display: flex;
  }

  .panel-header {
    display: none;
  }
}

.editor-footer {
  display: flex;
  align-items: center;
  gap: 16px;
  height: 44px;
  padding: 0 16px;
  flex-shrink: 0;
  background: var(--bg-toolbar);
  border-top: 1px solid var(--border-color);
  position: sticky;
  bottom: 0;
  z-index: 10;
}

.diff-editor {
  flex: 1;
}