/* 
 * 全局样式定义 
 * 遵循极简现代设计原则
 */

/* 字体引入：思源黑体 */
@import url('https://fonts.googleapis.com/css2?family=Noto+Sans+SC:wght@300;400;500;700&display=swap');

/* 设计令牌 (Design Tokens) */
:root {
  /* 色彩系统 */
  --color-charcoal: #2C2C2C;   /* 主色调：深炭灰 */
  --color-warm-white: #FAF9F6; /* 主背景：暖白 */
  --color-sandstone: #C4B8A5;  /* 辅助色：砂岩色 */
  --color-navy: #1A2B4C;       /* 辅助色：海军蓝 */
  --color-rust: #A6422C;       /* 强调色：锈红 */
  --color-text-main: #2C2C2C;
  --color-text-light: #555555;
  
  /* 字体系统 */
  --font-main: "Noto Sans SC", "Helvetica Neue", Helvetica, Arial, sans-serif;
  --font-display: "Helvetica Now Display", "Noto Sans SC", sans-serif;

  /* 间距系统 */
  --spacing-unit: 8px;
  --spacing-sm: 16px;
  --spacing-md: 32px;
  --spacing-lg: 64px;
  --spacing-xl: 120px;

  /* 布局 */
  --container-width: 1400px;
  --header-height: 80px;

  /* 动效 */
  --transition-base: 0.3s ease;
  --transition-smooth: 0.6s cubic-bezier(0.22, 1, 0.36, 1);
}

/* 基础重置与全局设置 */
*, *::before, *::after {
  box-sizing: border-box;
  margin: 0;
  padding: 0;
}

html {
  font-size: 16px;
  scroll-behavior: smooth;
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
}

body {
  font-family: var(--font-main);
  background-color: var(--color-warm-white);
  color: var(--color-text-main);
  line-height: 1.6;
  overflow-x: hidden;
}

/* 排版系统 */
h1, h2, h3, h4, h5, h6 {
  font-family: var(--font-display);
  font-weight: 500;
  line-height: 1.2;
  margin-bottom: var(--spacing-sm);
}

h1 { font-size: clamp(3rem, 5vw, 5rem); } /* 80px responsive */
h2 { font-size: clamp(2rem, 3vw, 3rem); } /* 48px responsive */
h3 { font-size: 1.5rem; }
p { font-weight: 300; margin-bottom: 1rem; }

.text-light { font-weight: 300; }
.text-medium { font-weight: 500; }
.text-caption { font-size: 0.875rem; color: var(--color-text-light); }

/* 链接与按钮 */
a {
  text-decoration: none;
  color: inherit;
  transition: color var(--transition-base);
}

a:hover {
  color: var(--color-sandstone);
}

.btn-minimal {
  display: inline-block;
  padding: 12px 32px;
  border: 1px solid var(--color-charcoal);
  background: transparent;
  color: var(--color-charcoal);
  font-size: 0.9rem;
  letter-spacing: 1px;
  cursor: pointer;
  transition: all var(--transition-base);
}

.btn-minimal:hover {
  background: var(--color-charcoal);
  color: var(--color-warm-white);
}

/* 布局辅助类 */
.container {
  width: 100%;
  max-width: var(--container-width);
  margin: 0 auto;
  padding: 0 var(--spacing-md);
}

.section-padding {
  padding: var(--spacing-xl) 0;
}

.grid-12 {
  display: grid;
  grid-template-columns: repeat(12, 1fr);
  gap: var(--spacing-md);
}

.flex-center {
  display: flex;
  justify-content: center;
  align-items: center;
}

.full-screen {
  width: 100%;
  height: 100vh;
  position: relative;
  overflow: hidden;
}

/* 导航系统 */
.navbar {
  position: fixed;
  top: 0;
  left: 0;
  width: 100%;
  height: var(--header-height);
  z-index: 1000;
  display: flex;
  justify-content: space-between;
  align-items: center;
  padding: 0 var(--spacing-md);
  transition: background-color var(--transition-base), padding var(--transition-base);
}

.navbar.scrolled {
  background-color: rgba(250, 249, 246, 0.95);
  backdrop-filter: blur(10px);
  box-shadow: 0 2px 20px rgba(0,0,0,0.03);
}

.nav-links {
  display: flex;
  gap: var(--spacing-md);
}

.nav-links a {
  font-size: 0.9rem;
  text-transform: uppercase;
  letter-spacing: 1px;
  position: relative;
}

.nav-links a::after {
  content: '';
  position: absolute;
  bottom: -4px;
  left: 0;
  width: 0;
  height: 1px;
  background-color: var(--color-charcoal);
  transition: width var(--transition-base);
}

.nav-links a:hover::after {
  width: 100%;
}

.mobile-menu-btn {
  display: none;
  font-size: 1.5rem;
  cursor: pointer;
  z-index: 1100;
}

/* 全屏大图展示 (Hero Section) */
.hero-section {
  position: relative;
  width: 100%;
  height: 100vh;
  display: flex;
  align-items: center;
  justify-content: center;
  overflow: hidden;
}

.hero-bg {
  position: absolute;
  top: 0;
  left: 0;
  width: 100%;
  height: 100%;
  z-index: 0;
}

.hero-bg img {
  width: 100%;
  height: 100%;
  object-fit: cover;
  transition: transform 10s ease; /* 慢速缩放动效 */
}

.hero-content {
  position: relative;
  z-index: 10;
  text-align: center;
  color: #fff; /* 在深色图片上显示 */
  mix-blend-mode: difference; /* 确保文字可见性 */
}

.scroll-indicator {
  position: absolute;
  bottom: 40px;
  left: 50%;
  transform: translateX(-50%);
  z-index: 10;
  animation: bounce 2s infinite;
  opacity: 0.7;
}

/* 图像交互 */
.img-hover-zoom {
  overflow: hidden;
  position: relative;
}

.img-hover-zoom img {
  width: 100%;
  height: 100%;
  object-fit: cover;
  transition: transform var(--transition-smooth);
}

.img-hover-zoom:hover img {
  transform: scale(1.05);
}

/* 动画关键帧 */
@keyframes bounce {
  0%, 20%, 50%, 80%, 100% { transform: translate(-50%, 0); }
  40% { transform: translate(-50%, 10px); }
  60% { transform: translate(-50%, 5px); }
}

@keyframes fadeIn {
  from { opacity: 0; transform: translateY(20px); }
  to { opacity: 1; transform: translateY(0); }
}

.fade-in-up {
  animation: fadeIn 1s cubic-bezier(0.22, 1, 0.36, 1) forwards;
}

/* 工具类：显隐控制 */
.hidden { display: none !important; }
.visible { display: block !important; }

/* 响应式断点 */
@media (max-width: 1024px) {
  :root {
    --spacing-xl: 80px;
  }
}

@media (max-width: 768px) {
  .nav-links {
    position: fixed;
    top: 0;
    right: -100%;
    width: 70%;
    height: 100vh;
    background-color: var(--color-warm-white);
    flex-direction: column;
    justify-content: center;
    align-items: center;
    transition: right var(--transition-smooth);
    box-shadow: -5px 0 20px rgba(0,0,0,0.1);
  }

  .nav-links.active {
    right: 0;
  }

  .mobile-menu-btn {
    display: block;
  }

  .grid-12 {
    grid-template-columns: 1fr;
  }
  
  h1 { font-size: 2.5rem; }
  
  .hero-content h1 {
    font-size: 2rem;
    padding: 0 20px;
  }
}

/* 页脚 */
.site-footer {
  text-align: center;
  padding: var(--spacing-lg) 0;
  border-top: 1px solid rgba(0,0,0,0.05);
  margin-top: var(--spacing-xl);
}

.footer-logo {
  font-weight: 700;
  letter-spacing: 2px;
  margin-bottom: var(--spacing-md);
  display: block;
}

/* 内容槽位 (TS框架规范模拟) */
.slot-content:empty::before {
  content: 'Content Slot';
  color: #ccc;
  display: flex;
  align-items: center;
  justify-content: center;
  height: 100%;
  background: #f5f5f5;
  border: 1px dashed #ddd;
}