/* ========================================
   SHUJI 述己 - 公共样式 / 设计令牌
   ======================================== */

/* --- CSS 变量 --- */
:root {
  /* 主色调 */
  --color-bg: #FAF8F4;
  --color-bg-alt: #F0EDE6;
  --color-white: #FFFFFF;
  --color-black: #0A0A0A;
  --color-text: #1A1A1A;
  --color-text-light: #6B6B6B;
  --color-text-muted: #999999;
  
  /* 点缀色 */
  --color-accent-red: #B83535;
  --color-accent-green: #4A6B5F;
  --color-accent-gold: #D4B87A;
  --color-accent-blue: #5A7D8F;
  --color-accent-pink: #C89090;
  --color-accent-neon: #FF6B35;
  
  /* 玻璃拟态 */
  --color-glass-bg: rgba(255,255,255,0.08);
  --color-glass-border: rgba(255,255,255,0.12);
  
  /* 边框 */
  --color-border: #D9D5CC;
  --color-border-light: #E8E4DC;
  
  /* 字体 */
  --font-cn: "PingFang SC", "Microsoft YaHei", "Hiragino Sans GB", sans-serif;
  --font-en: Georgia, "Times New Roman", serif;
  --font-mono: "SF Mono", "JetBrains Mono", "Consolas", monospace;
  
  /* 间距 */
  --space-xs: 6px;
  --space-sm: 12px;
  --space-md: 20px;
  --space-lg: 32px;
  --space-xl: 40px;
  --space-2xl: 60px;
  --space-3xl: 80px;
  --space-4xl: 120px;
  
  /* 字号 */
  --fs-xs: 12px;
  --fs-sm: 14px;
  --fs-base: 16px;
  --fs-md: 20px;
  --fs-lg: 28px;
  --fs-xl: 36px;
  --fs-2xl: 48px;
  --fs-3xl: 64px;
  --fs-display: 96px;
  --fs-hero: 80px;
  --fs-mega: 120px;
  --fs-eyebrow: 11px;
  
  /* 导航高度 */
  --nav-height: 72px;
  
  /* 最大宽度 */
  --max-width: 1320px;
  
  /* 圆角 */
  --radius-sm: 8px;
  --radius-md: 16px;
  --radius-lg: 20px;
  --radius-xl: 24px;
  
  /* 阴影 */
  --shadow-sm: 0 2px 12px rgba(0,0,0,0.05);
  --shadow-md: 0 8px 30px rgba(0,0,0,0.08);
  --shadow-lg: 0 16px 48px rgba(0,0,0,0.12);
  --shadow-glow: 0 0 32px rgba(184,53,53,0.4);
  
  /* 过渡 */
  --transition-fast: 0.2s ease;
  --transition-base: 0.35s ease;
  --transition-slow: 0.6s cubic-bezier(0.25, 0.46, 0.45, 0.94);
}

/* 深色模式变量覆盖 */
[data-theme="dark"] {
  --color-bg: #0F0F0F;
  --color-bg-alt: #1A1A1A;
  --color-white: #1E1E1E;
  --color-black: #F0EDE6;
  --color-text: #E8E4DC;
  --color-text-light: #A8A49E;
  --color-text-muted: #706C66;
  --color-border: #333030;
  --color-border-light: #2A2826;
  --color-glass-bg: rgba(0,0,0,0.2);
  --color-glass-border: rgba(255,255,255,0.06);
  --shadow-sm: 0 2px 12px rgba(0,0,0,0.2);
  --shadow-md: 0 8px 30px rgba(0,0,0,0.3);
  --shadow-lg: 0 16px 48px rgba(0,0,0,0.4);
}

/* 深色模式下导航适配 */
[data-theme="dark"] .nav.scrolled {
  background: rgba(15,15,15,0.88);
  backdrop-filter: blur(20px);
  border-bottom: 1px solid rgba(255,255,255,0.06);
}

[data-theme="dark"] .nav.scrolled .nav-logo,
[data-theme="dark"] .nav.scrolled .nav-menu a,
[data-theme="dark"] .nav.scrolled .icon-btn {
  color: #E8E4DC;
}

[data-theme="dark"] .nav.scrolled .hamburger span {
  background: #E8E4DC;
}

[data-theme="dark"] .nav-menu a::after {
  background: var(--color-accent-gold);
}

/* 深色模式下暗色区块导航恢复白色 */
[data-theme="dark"] .nav.nav-dark {
  background: rgba(15,15,15,0.88);
}

[data-theme="dark"] .nav.nav-dark .nav-logo,
[data-theme="dark"] .nav.nav-dark .nav-menu a,
[data-theme="dark"] .nav.nav-dark .icon-btn {
  color: #E8E4DC;
}

/* 深色模式下暗色区块调整为略亮于背景 */
[data-theme="dark"] .section-dark,
[data-theme="dark"] .section-cta,
[data-theme="dark"] .section-brand {
  background: #181818 !important;
}

[data-theme="dark"] .footer {
  background: #181818;
}

[data-theme="dark"] .footer::before {
  color: rgba(255,255,255,0.02);
}

[data-theme="dark"] .cta-form input {
  background: rgba(255,255,255,0.06);
  border-color: rgba(255,255,255,0.1);
}

[data-theme="dark"] .cta-form input:focus {
  box-shadow: 0 0 0 4px rgba(184,53,53,0.25);
}

[data-theme="dark"] .back-to-top {
  background: var(--color-white);
  border-color: var(--color-border);
}

/* --- 全局重置 --- */
*, *::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-cn);
  font-size: var(--fs-base);
  color: var(--color-text);
  background-color: var(--color-bg);
  line-height: 1.8;
  overflow-x: hidden;
  font-weight: 400;
  -webkit-font-smoothing: antialiased;
  animation: pageIn 0.5s ease both;
  transition: background-color 0.4s ease, color 0.4s ease;
}

/* 移动端菜单展开时锁定滚动 */
body.menu-open {
  overflow: hidden !important;
  position: fixed !important;
  width: 100% !important;
}

@keyframes pageIn {
  from { opacity: 0; }
  to   { opacity: 1; }
}

/* 页面过渡遮罩 */
.page-transition-overlay {
  position: fixed;
  inset: 0;
  z-index: 10000;
  background: #0D0D0D;
  pointer-events: none;
  opacity: 0;
  transition: opacity 0.35s ease;
}

.page-transition-overlay.active {
  opacity: 1;
}

/* 全局噪点纹理 */
body::before {
  content: '';
  position: fixed;
  inset: 0;
  z-index: 5;
  pointer-events: none;
  opacity: 0.025;
  background-image: url("data:image/svg+xml,%3Csvg viewBox='0 0 256 256' xmlns='http://www.w3.org/2000/svg'%3E%3Cfilter id='n'%3E%3CfeTurbulence type='fractalNoise' baseFrequency='0.75' numOctaves='4' stitchTiles='stitch'/%3E%3C/filter%3E%3Crect width='100%25' height='100%25' filter='url(%23n)' opacity='0.5'/%3E%3C/svg%3E");
  background-size: 256px 256px;
}

a {
  color: inherit;
  text-decoration: none;
  transition: color var(--transition-fast);
}

a:hover {
  color: var(--color-accent-red);
}

img {
  max-width: 100%;
  height: auto;
  display: block;
}

/* --- 图片加载占位 --- */
img {
  background: var(--color-bg-alt);
}

/* --- 自定义滚动条 --- */
::-webkit-scrollbar {
  width: 6px;
}

::-webkit-scrollbar-track {
  background: var(--color-bg);
}

::-webkit-scrollbar-thumb {
  background: var(--color-border);
  border-radius: 3px;
}

::-webkit-scrollbar-thumb:hover {
  background: var(--color-text-muted);
}

/* --- 文字选中 --- */
::selection {
  background: rgba(196, 75, 75, 0.2);
  color: var(--color-text);
}

::-moz-selection {
  background: rgba(196, 75, 75, 0.2);
  color: var(--color-text);
}

/* --- 图片懒加载渐入 --- */
img[loading="lazy"] {
  opacity: 0;
  transition: opacity 0.5s ease;
}

img[loading="lazy"].loaded {
  opacity: 1;
}

button {
  cursor: pointer;
  border: none;
  outline: none;
  font-family: inherit;
}

ul, ol {
  list-style: none;
}

/* --- 容器 --- */
.container {
  max-width: var(--max-width);
  margin: 0 auto;
  padding: 0 var(--space-xl);
}

.container-wide {
  max-width: 1440px;
  margin: 0 auto;
  padding: 0 var(--space-xl);
}

/* --- 导航栏 --- */
.nav {
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  z-index: 1000;
  height: var(--nav-height);
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 0 var(--space-3xl);
  background: transparent;
  transition: background var(--transition-base), box-shadow var(--transition-base), height var(--transition-base);
}

.nav.scrolled {
  background: rgba(255, 255, 255, 0.78);
  backdrop-filter: blur(20px) saturate(1.5);
  -webkit-backdrop-filter: blur(20px) saturate(1.5);
  box-shadow: 0 1px 0 rgba(0,0,0,0.06);
  border-bottom: 1px solid rgba(0,0,0,0.04);
}

.nav.nav-dark {
  background: rgba(10, 10, 10, 0.85);
  backdrop-filter: blur(20px);
  -webkit-backdrop-filter: blur(20px);
  border-bottom: 1px solid rgba(255,255,255,0.08);
}

.nav.nav-dark .nav-logo,
.nav.nav-dark .nav-menu a,
.nav.nav-dark .icon-btn {
  color: #fff;
}

.nav.nav-dark .nav-menu a::after {
  background: var(--color-accent-gold);
}

.nav.nav-dark .hamburger span {
  background: #fff;
}

.nav-logo {
  font-family: var(--font-en);
  font-size: var(--fs-lg);
  font-weight: bold;
  letter-spacing: 3px;
  color: var(--color-black);
}

.nav-logo .dot {
  color: var(--color-accent-red);
}

.nav-menu {
  display: flex;
  align-items: center;
  gap: var(--space-2xl);
}

.nav-menu a {
  font-size: var(--fs-sm);
  letter-spacing: 1px;
  position: relative;
}

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

.nav-menu a:hover::after,
.nav-menu a.active::after {
  width: 100%;
}

.nav-actions {
  display: flex;
  align-items: center;
  gap: var(--space-lg);
}

.nav-actions .icon-btn {
  width: 36px;
  height: 36px;
  display: flex;
  align-items: center;
  justify-content: center;
  background: none;
  font-size: 18px;
  color: var(--color-text);
  border-radius: 50%;
  transition: background var(--transition-fast);
}

.nav-actions .icon-btn:hover {
  background: var(--color-border-light);
}

/* 主题切换按钮 */
.theme-toggle .theme-icon-dark { display: none; }
[data-theme="dark"] .theme-toggle .theme-icon-light { display: none; }
[data-theme="dark"] .theme-toggle .theme-icon-dark { display: inline; }

/* 汉堡菜单 */
.hamburger {
  display: none;
  flex-direction: column;
  gap: 5px;
  background: none;
  padding: 4px;
}

.hamburger span {
  display: block;
  width: 22px;
  height: 2px;
  background: var(--color-text);
  transition: var(--transition-base);
}

.hamburger.active span:nth-child(1) {
  transform: rotate(45deg) translate(5px, 5px);
}

.hamburger.active span:nth-child(2) {
  opacity: 0;
}

.hamburger.active span:nth-child(3) {
  transform: rotate(-45deg) translate(5px, -5px);
}

/* --- 页脚 --- */
.footer {
  background: #0D0D0D;
  color: var(--color-text-muted);
  padding: var(--space-4xl) 0 var(--space-xl);
  position: relative;
  overflow: hidden;
}

/* 背景水印 "2m²" */
.footer::before {
  content: '2m²';
  position: absolute;
  right: -40px;
  bottom: -20px;
  font-family: var(--font-en);
  font-size: 280px;
  font-weight: 700;
  color: rgba(255,255,255,0.015);
  line-height: 1;
  pointer-events: none;
  user-select: none;
}

/* 品牌 slogan */
.footer-slogan {
  font-family: var(--font-en);
  font-size: var(--fs-2xl);
  font-weight: 300;
  color: var(--color-white);
  letter-spacing: 2px;
  margin-bottom: var(--space-2xl);
  padding-bottom: var(--space-2xl);
  border-bottom: 1px solid rgba(255,255,255,0.08);
}

.footer-slogan .dot {
  color: var(--color-accent-red);
}

.footer-grid {
  display: grid;
  grid-template-columns: 2fr 1fr 1fr 1fr;
  gap: var(--space-3xl);
  padding-bottom: var(--space-3xl);
  border-bottom: 1px solid rgba(255,255,255,0.1);
}

.footer-brand .footer-logo {
  font-family: var(--font-en);
  font-size: var(--fs-lg);
  color: var(--color-white);
  margin-bottom: var(--space-md);
}

.footer-brand p {
  font-size: var(--fs-sm);
  line-height: 1.8;
  margin-bottom: var(--space-lg);
}

.footer-social {
  display: flex;
  gap: var(--space-md);
}

.footer-social a {
  width: 36px;
  height: 36px;
  display: flex;
  align-items: center;
  justify-content: center;
  border-radius: 50%;
  font-size: 14px;
  color: rgba(255,255,255,0.35);
  transition: all var(--transition-fast);
}

.footer-social a:hover {
  color: #fff;
  background: rgba(255,255,255,0.08);
}

.footer-col h4 {
  font-size: var(--fs-sm);
  color: var(--color-white);
  margin-bottom: var(--space-lg);
  letter-spacing: 1px;
  font-weight: 500;
}

.footer-col a {
  display: block;
  font-size: var(--fs-sm);
  color: var(--color-text-muted);
  margin-bottom: var(--space-sm);
  transition: all var(--transition-fast);
}

.footer-col a:hover {
  color: var(--color-white);
  transform: translateX(2px);
}

.footer-bottom {
  padding-top: var(--space-xl);
  display: flex;
  justify-content: space-between;
  align-items: center;
  font-size: var(--fs-xs);
}

.footer-bottom a {
  color: var(--color-text-muted);
}

.footer-bottom a:hover {
  color: var(--color-white);
}

/* --- 按钮 --- */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  padding: 14px 40px;
  font-size: var(--fs-sm);
  letter-spacing: 2px;
  border: 1.5px solid var(--color-text);
  background: transparent;
  color: var(--color-text);
  border-radius: var(--radius-sm);
  transition: all var(--transition-base);
  cursor: pointer;
  font-weight: 500;
  position: relative;
  overflow: hidden;
}

/* 按钮光斑跟随效果（需要 JS 设置 --mx, --my） */
.btn.btn-glow {
  --mx: 50%;
  --my: 50%;
}

.btn.btn-glow::before {
  content: '';
  position: absolute;
  inset: 0;
  background: radial-gradient(circle at var(--mx) var(--my), rgba(184,53,53,0.18) 0%, transparent 60%);
  opacity: 0;
  transition: opacity 0.3s ease;
  pointer-events: none;
  z-index: 0;
}

.btn.btn-glow:hover::before {
  opacity: 1;
}

.btn.btn-glow > * {
  position: relative;
  z-index: 1;
}

.btn:hover {
  background: var(--color-text);
  color: var(--color-white);
}

.btn-primary {
  background: var(--color-accent-red);
  border-color: var(--color-accent-red);
  color: var(--color-white);
}

.btn-primary:hover {
  background: var(--color-accent-neon);
  border-color: var(--color-accent-neon);
  box-shadow: var(--shadow-glow);
}

.btn-outline {
  border-color: var(--color-border);
  color: var(--color-text);
}

.btn-outline:hover {
  border-color: var(--color-text);
  background: var(--color-text);
  color: var(--color-white);
}

/* --- 段落标题 --- */
.section-label {
  font-family: var(--font-en);
  font-size: var(--fs-xs);
  letter-spacing: 4px;
  color: var(--color-accent-red);
  text-transform: uppercase;
  margin-bottom: var(--space-md);
  font-weight: 600;
}

.section-title {
  font-size: var(--fs-2xl);
  font-weight: 500;
  color: var(--color-text);
  line-height: 1.25;
  margin-bottom: var(--space-md);
  letter-spacing: 1px;
}

.section-desc {
  font-size: var(--fs-base);
  color: var(--color-text-light);
  line-height: 1.8;
  max-width: 600px;
}

/* --- 通用动画 --- */
.fade-in {
  opacity: 0;
  transform: translateY(30px);
  transition: opacity 0.8s ease, transform 0.8s ease;
}

.fade-in.visible {
  opacity: 1;
  transform: translateY(0);
}

/* stagger 延迟入场 */
.stagger-1 { transition-delay: 0ms; }
.stagger-2 { transition-delay: 80ms; }
.stagger-3 { transition-delay: 160ms; }
.stagger-4 { transition-delay: 240ms; }
.stagger-5 { transition-delay: 320ms; }

/* --- 回到顶部 --- */
.back-to-top {
  position: fixed;
  bottom: 40px;
  right: 40px;
  width: 48px;
  height: 48px;
  border-radius: 50%;
  background: var(--color-white);
  border: 1px solid var(--color-border);
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 18px;
  color: var(--color-text);
  box-shadow: var(--shadow-md);
  opacity: 0;
  visibility: hidden;
  transition: all var(--transition-base);
  z-index: 999;
}

.back-to-top.visible {
  opacity: 1;
  visibility: visible;
}

.back-to-top:hover {
  background: var(--color-text);
  color: var(--color-white);
}

/* --- 响应式 --- */
@media (max-width: 1024px) {
  :root {
    --nav-height: 64px;
    --fs-2xl: 36px;
    --fs-3xl: 48px;
    --fs-hero: 56px;
  }
  
  .footer-grid {
    grid-template-columns: 1fr 1fr;
    gap: var(--space-2xl);
  }
  
  .container, .container-wide {
    padding: 0 var(--space-lg);
  }
}

@media (max-width: 768px) {
  .hamburger {
    display: flex;
  }
  
  .nav-menu {
    position: fixed;
    top: var(--nav-height);
    left: 0;
    right: 0;
    bottom: 0;
    background: #FFFFFF;
    flex-direction: column;
    justify-content: center;
    gap: var(--space-2xl);
    transform: translateX(100%);
    transition: transform var(--transition-base);
    z-index: 1001;
    border-top: 1px solid var(--color-border-light);
    overflow-y: auto;
  }

  [data-theme="dark"] .nav-menu {
    background: #1E1E1E;
    border-top-color: rgba(255,255,255,0.06);
  }

  .nav-menu a {
    font-size: var(--fs-lg);
    color: var(--color-text);
  }

  /* 移动端菜单无视 nav-dark 白色文字 */
  .nav.nav-dark .nav-menu a,
  .nav.scrolled.nav-dark .nav-menu a {
    color: var(--color-text);
  }

  /* 深色模式下的移动菜单 */
  [data-theme="dark"] .nav-menu a {
    color: var(--color-text);
  }
  
  .nav-menu.open {
    transform: translateX(0);
  }
  
  .footer-grid {
    grid-template-columns: 1fr;
  }
  
  .footer-bottom {
    flex-direction: column;
    gap: var(--space-sm);
    text-align: center;
  }
  
  .nav {
    padding: 0 var(--space-xl);
  }
}