/* --- 全局样式定义 - 绅士格调 --- */

/* 设计令牌 */
:root {
  /* 颜色 */
  --color-primary: #1a1a1a;
  --color-background-light: #f8f8f8;
  --color-text-dark: #333;
  --color-text-light: #f0f0f0;
  --color-text-subtle: #666;
  --color-text-footer: #999;
  --color-accent-hover: #000;

  /* 字体 */
  --font-family: "Source Han Sans CN", "PingFang SC", "Helvetica Neue", Arial, sans-serif;
  
  /* 间距 */
  --spacing-xs: 0.5rem;
  --spacing-sm: 1rem;
  --spacing-md: 2rem;
  --spacing-lg: 4rem;
  
  /* 圆角 */
  --radius-none: 0;
  
  /* 阴影 */
  --shadow-nav: 0 2px 5px rgba(0, 0, 0, 0.1);
}

/* --- 重置与基础样式 --- */
*,
*::before,
*::after {
  box-sizing: border-box;
}

html {
  scroll-behavior: smooth;
}

body {
  margin: 0;
  padding: 0;
  font-family: var(--font-family);
  font-size: 1rem;
  color: var(--color-text-dark);
  background-color: var(--color-background-light);
  line-height: 1.7;
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
}

/* --- 布局容器 --- */
.container {
  width: 90%;
  max-width: 1200px;
  margin-left: auto;
  margin-right: auto;
}

/* --- 导航栏 --- */
.nav-container {
  display: flex;
  justify-content: space-between;
  align-items: center;
  padding: var(--spacing-sm) 0;
}

.logo {
  font-size: 1.5rem;
  font-weight: 700;
  letter-spacing: 1px;
  text-decoration: none;
  color: var(--color-primary);
}

.nav-links {
  display: flex;
}

.nav-links a {
  margin-left: var(--spacing-md);
  text-decoration: none;
  color: var(--color-text-subtle);
  font-weight: 300;
  letter-spacing: 0.5px;
  transition: color 0.3s ease;
}

.nav-links a:hover {
  color: var(--color-accent-hover);
}

/* --- 页面区块 --- */
.hero,
.feature {
  text-align: center;
  padding: var(--spacing-lg) 0;
}

.hero h1 {
  font-size: 3rem;
  font-weight: 300;
  letter-spacing: 2px;
  margin-top: 0;
  margin-bottom: var(--spacing-sm);
  color: var(--color-primary);
}

.hero p {
  font-size: 1.125rem;
  color: var(--color-text-subtle);
  max-width: 600px;
  margin: 0 auto var(--spacing-md);
  letter-spacing: 0.5px;
}

.hero-image {
  width: 100%;
  max-width: 800px;
  margin: 0 auto;
}

/* --- 深色区块 --- */
.dark-section {
  background-color: var(--color-primary);
  color: var(--color-text-light);
}

.dark-section h2 {
  color: var(--color-text-light);
}

.dark-section p {
  color: #ccc;
}

/* --- 图片网格 --- */
.image-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
  gap: var(--spacing-md);
  padding: var(--spacing-md) 0;
}

.grid-item {
  overflow: hidden;
}

.grid-item img {
  width: 100%;
  height: 100%;
  object-fit: cover;
  transition: transform 0.5s ease, filter 0.5s ease;
  display: block;
}

.grid-item:hover img {
  transform: scale(1.05);
  filter: brightness(1.1);
}

/* --- 文字内容 --- */
h2 {
  font-size: 2.25rem;
  font-weight: 300;
  letter-spacing: 1.5px;
  margin-top: 0;
  margin-bottom: var(--spacing-md);
  color: var(--color-primary);
}

.text-content {
  max-width: 800px;
  margin: 0 auto;
  line-height: 1.8;
  color: var(--color-text-subtle);
}

/* --- 页脚 --- */
footer {
  text-align: center;
  padding: var(--spacing-md) 0;
  background-color: var(--color-primary);
  color: var(--color-text-footer);
  font-size: 0.9rem;
}

/* --- 响应式设计 --- */
@media (max-width: 768px) {
  .nav-links {
    display: none; /* 在真实项目中会替换为汉堡菜单 */
  }
  
  .hero h1 {
    font-size: 2rem;
  }
  
  .container {
    width: 95%;
    padding: 0 var(--spacing-sm);
  }

  .image-grid {
    grid-template-columns: 1fr;
    gap: var(--spacing-sm);
  }
}