:root {
  --bg-primary: #f5f5f5;
  --bg-secondary: white;
  --text-primary: #333;
  --border-color: #e0e0e0;
  --link-color: #667eea;
}

.dark-mode {
  --bg-primary: #1a1a1a;
  --bg-secondary: #2a2a2a;
  --text-primary: #e0e0e0;
  --border-color: #444;
  --link-color: #5a67d8;
}

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

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

.container {
  display: flex;
  flex-direction: column;
  min-height: 100vh;
  max-width: 800px;
  margin: 0 auto;
  background: var(--bg-secondary);
}

.header {
  padding: 16px 20px;
  border-bottom: 1px solid var(--border-color);
  font-size: 20px;
  font-weight: 600;
  color: var(--text-primary);
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 16px;
}

.header-left {
  display: flex;
  align-items: center;
  gap: 4px;
  flex-shrink: 0;
}

.header-right {
  display: flex;
  align-items: center;
  gap: 10px;
}

.header-title {
  font-size: 20px;
  font-weight: 600;
  color: var(--text-primary);
  display: flex;
  align-items: center;
  gap: 10px;
}

.header-logo {
  width: 28px;
  height: 28px;
  display: block;
}

.theme-toggle {
  background: none;
  border: none;
  font-size: 18px;
  cursor: pointer;
  padding: 6px;
  border-radius: 50%;
  transition: background-color 0.2s;
  width: 32px;
  height: 32px;
  display: flex;
  align-items: center;
  justify-content: center;
}

.theme-toggle:hover {
  background: rgba(0, 0, 0, 0.1);
}

.dark-mode .theme-toggle:hover {
  background: rgba(255, 255, 255, 0.1);
}

.soft-back-btn {
  display: flex;
  align-items: center;
  justify-content: center;
  color: var(--text-primary);
  opacity: 0.6;
  transition: opacity 0.2s;
  padding: 8px;
  border-radius: 50%;
}

.soft-back-btn:hover {
  opacity: 1;
  background-color: rgba(0, 0, 0, 0.05);
}

.dark-mode .soft-back-btn {
  opacity: 0.9;
}

.dark-mode .soft-back-btn:hover {
  background-color: rgba(255, 255, 255, 0.1);
}

.content {
  flex: 1;
  padding: 20px;
  overflow-y: auto;
}

.content>div {
  padding: 20px;
  background: var(--bg-secondary);
  border-radius: 8px;
  box-shadow: 0 2px 4px rgba(0, 0, 0, 0.1);
}

.content h2 {
  margin-bottom: 10px;
  color: var(--text-primary);
}

.content p {
  margin-bottom: 15px;
  line-height: 1.6;
}

.content ul {
  margin-bottom: 20px;
  padding-left: 20px;
}

.content li {
  margin-bottom: 8px;
  line-height: 1.5;
}

.content a {
  color: var(--link-color);
  text-decoration: none;
}

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

/* Mobile Optimizations */
@media (max-width: 768px) {
  .container {
    max-width: 100%;
  }

  .header {
    padding: 12px 12px;
    font-size: 16px;
    gap: 8px;
  }

  .header-left {
    gap: 2px;
  }

  .header-logo {
    width: 24px;
    height: 24px;
  }

  .soft-back-btn {
    padding: 6px;
  }

  .content {
    padding: 16px;
  }

  .content>div {
    padding: 16px;
  }
}