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

body {
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "Helvetica Neue", Arial, "Noto Sans", sans-serif;
  line-height: 1.6;
  color: #333;
  background-color: #f5f5f5;
  min-height: 100vh;
}

.container {
  max-width: 1200px;
  margin: 0 auto;
  padding: 20px;
}

/* 头部 */
.header {
  text-align: center;
  padding: 30px 0;
  background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
  color: white;
  border-radius: 12px;
  margin-bottom: 20px;
}

.header h1 {
  font-size: 2rem;
  margin-bottom: 10px;
}

.subtitle {
  opacity: 0.9;
  font-size: 1rem;
}

/* 搜索区域 */
.search-section {
  background: white;
  padding: 25px;
  border-radius: 12px;
  margin-bottom: 20px;
  box-shadow: 0 2px 8px rgba(0,0,0,0.08);
}

.search-box {
  display: flex;
  gap: 10px;
  margin-bottom: 15px;
}

.search-box input {
  flex: 1;
  padding: 12px 16px;
  border: 2px solid #e0e0e0;
  border-radius: 8px;
  font-size: 1rem;
  transition: border-color 0.2s;
}

.search-box input:focus {
  outline: none;
  border-color: #667eea;
}

.search-box button {
  padding: 12px 28px;
  background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
  color: white;
  border: none;
  border-radius: 8px;
  font-size: 1rem;
  cursor: pointer;
  transition: transform 0.1s, box-shadow 0.2s;
}

.search-box button:hover {
  transform: translateY(-1px);
  box-shadow: 0 4px 12px rgba(102, 126, 234, 0.4);
}

.hot-questions {
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
  align-items: center;
}

.hot-label {
  color: #666;
  font-size: 0.9rem;
}

.hot-tag {
  padding: 4px 12px;
  background: #f0f0f0;
  border: 1px solid #ddd;
  border-radius: 20px;
  font-size: 0.85rem;
  cursor: pointer;
  transition: all 0.2s;
}

.hot-tag:hover {
  background: #667eea;
  color: white;
  border-color: #667eea;
}

/* 主体内容 */
.main-content {
  display: grid;
  grid-template-columns: 260px 1fr;
  gap: 20px;
}

/* 侧边栏 */
.sidebar {
  background: white;
  border-radius: 12px;
  padding: 20px;
  box-shadow: 0 2px 8px rgba(0,0,0,0.08);
  height: fit-content;
  position: sticky;
  top: 20px;
}

.sidebar-section {
  margin-bottom: 25px;
}

.sidebar-section:last-child {
  margin-bottom: 0;
}

.sidebar-section h3 {
  font-size: 1rem;
  margin-bottom: 12px;
  color: #333;
  border-bottom: 2px solid #f0f0f0;
  padding-bottom: 8px;
}

.category-list {
  list-style: none;
}

.category-item {
  display: block;
  padding: 8px 12px;
  margin-bottom: 4px;
  border-radius: 6px;
  color: #555;
  text-decoration: none;
  transition: all 0.2s;
  cursor: pointer;
}

.category-item:hover {
  background: #f0f0f0;
  color: #333;
}

.category-item.active {
  background: #667eea;
  color: white;
}

.stats {
  font-size: 0.9rem;
  color: #666;
}

.stats p {
  margin-bottom: 5px;
}

.random-quote {
  font-size: 0.85rem;
  line-height: 1.5;
  color: #555;
  font-style: italic;
  background: #f9f9f9;
  padding: 12px;
  border-radius: 6px;
  border-left: 3px solid #667eea;
}

/* 内容区域 */
.content-area {
  background: white;
  border-radius: 12px;
  padding: 25px;
  box-shadow: 0 2px 8px rgba(0,0,0,0.08);
  min-height: 500px;
}

.welcome-message {
  text-align: center;
  padding: 60px 20px;
  color: #666;
}

.welcome-message h2 {
  margin-bottom: 20px;
  color: #333;
}

.welcome-message ul {
  display: inline-block;
  text-align: left;
  margin: 20px 0;
}

.welcome-message li {
  margin-bottom: 8px;
}

.disclaimer {
  margin-top: 30px;
  font-size: 0.85rem;
  color: #999;
}

/* 搜索结果 */
.result-item {
  border-bottom: 1px solid #eee;
  padding: 20px 0;
}

.result-item:first-child {
  padding-top: 0;
}

.result-item:last-child {
  border-bottom: none;
  padding-bottom: 0;
}

.result-question {
  font-size: 1.1rem;
  font-weight: 600;
  color: #333;
  margin-bottom: 10px;
  display: flex;
  align-items: center;
  gap: 8px;
}

.category-badge {
  font-size: 0.75rem;
  padding: 2px 8px;
  background: #e8eaf6;
  color: #667eea;
  border-radius: 12px;
  font-weight: normal;
}

.result-answer {
  color: #444;
  line-height: 1.7;
}

.result-answer p {
  margin-bottom: 10px;
}

.no-results {
  text-align: center;
  padding: 60px 20px;
  color: #999;
}

.no-results p {
  font-size: 1.1rem;
}

/* 页脚 */
.footer {
  text-align: center;
  padding: 20px;
  color: #999;
  font-size: 0.9rem;
  margin-top: 20px;
}

/* 响应式 */
@media (max-width: 768px) {
  .container {
    padding: 10px;
  }

  .header h1 {
    font-size: 1.5rem;
  }

  .search-box {
    flex-direction: column;
  }

  .search-box button {
    width: 100%;
  }

  .main-content {
    grid-template-columns: 1fr;
  }

  .sidebar {
    position: static;
  }

  .hot-questions {
    justify-content: center;
  }
}