/* 
 * 标书代做网站 - 现代化 UI 设计
 * 基于东方智慧：上善若水，以柔克刚
 */

:root {
  /* 主色调 - 深蓝象征专业与信任 */
  --color-primary: #1e40af;
  --color-primary-light: #3b82f6;
  --color-primary-dark: #1e3a8a;
  --color-primary-gradient: linear-gradient(135deg, #1e40af 0%, #3b82f6 100%);
  
  /* 辅助色 - 金色象征成功与价值 */
  --color-accent: #f59e0b;
  --color-accent-light: #fbbf24;
  --color-accent-gradient: linear-gradient(135deg, #f59e0b 0%, #fbbf24 100%);
  
  /* 中性色 */
  --color-background: #f8fafc;
  --color-surface: #ffffff;
  --color-surface-hover: #f1f5f9;
  --color-text-primary: #0f172a;
  --color-text-secondary: #475569;
  --color-text-muted: #94a3b8;
  --color-border: #e2e8f0;
  
  /* 状态色 */
  --color-success: #10b981;
  --color-warning: #f59e0b;
  --color-error: #ef4444;
  --color-info: #3b82f6;
  
  /* 字体 */
  --font-primary: -apple-system, BlinkMacSystemFont, 'Segoe UI', 'PingFang SC', 'Hiragino Sans GB', 'Microsoft YaHei', 'Helvetica Neue', Helvetica, Arial, sans-serif;
  --font-mono: 'JetBrains Mono', 'Fira Code', monospace;
  
  /* 间距 */
  --space-xs: 0.25rem;
  --space-sm: 0.5rem;
  --space-md: 1rem;
  --space-lg: 1.5rem;
  --space-xl: 2rem;
  --space-2xl: 3rem;
  --space-3xl: 4rem;
  --space-4xl: 6rem;
  
  /* 圆角 */
  --radius-sm: 0.375rem;
  --radius-md: 0.5rem;
  --radius-lg: 0.75rem;
  --radius-xl: 1rem;
  --radius-2xl: 1.5rem;
  --radius-full: 9999px;
  
  /* 阴影 */
  --shadow-sm: 0 1px 2px 0 rgb(0 0 0 / 0.05);
  --shadow-md: 0 4px 6px -1px rgb(0 0 0 / 0.1), 0 2px 4px -2px rgb(0 0 0 / 0.1);
  --shadow-lg: 0 10px 15px -3px rgb(0 0 0 / 0.1), 0 4px 6px -4px rgb(0 0 0 / 0.1);
  --shadow-xl: 0 20px 25px -5px rgb(0 0 0 / 0.1), 0 8px 10px -6px rgb(0 0 0 / 0.1);
  --shadow-2xl: 0 25px 50px -12px rgb(0 0 0 / 0.25);
  
  /* 过渡 */
  --transition-fast: 150ms ease;
  --transition-normal: 250ms ease;
  --transition-slow: 350ms ease;
  
  /* 最大宽度 */
  --max-container: 80rem;
}

/* 重置与基础 */
*, *::before, *::after {
  box-sizing: border-box;
  margin: 0;
  padding: 0;
}

html {
  scroll-behavior: smooth;
  font-size: 16px;
}

body {
  font-family: var(--font-primary);
  background-color: var(--color-background);
  color: var(--color-text-primary);
  line-height: 1.6;
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
  overflow-x: hidden;
}

/* 容器 */
.container {
  width: 100%;
  max-width: var(--max-container);
  margin: 0 auto;
  padding: 0 var(--space-lg);
}

/* 按钮系统 */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: var(--space-sm);
  padding: var(--space-sm) var(--space-xl);
  font-weight: 600;
  font-size: 1rem;
  text-decoration: none;
  border-radius: var(--radius-lg);
  transition: all var(--transition-normal);
  cursor: pointer;
  border: none;
  outline: none;
  position: relative;
  overflow: hidden;
}

.btn::before {
  content: '';
  position: absolute;
  top: 0;
  left: -100%;
  width: 100%;
  height: 100%;
  background: linear-gradient(90deg, transparent, rgba(255,255,255,0.2), transparent);
  transition: left 0.5s;
}

.btn:hover::before {
  left: 100%;
}

.btn-primary {
  background: var(--color-primary-gradient);
  color: white;
  box-shadow: var(--shadow-md);
}

.btn-primary:hover {
  transform: translateY(-2px);
  box-shadow: var(--shadow-lg);
}

.btn-secondary {
  background: var(--color-surface);
  color: var(--color-primary);
  border: 2px solid var(--color-primary);
}

.btn-secondary:hover {
  background: var(--color-primary);
  color: white;
  transform: translateY(-2px);
}

.btn-lg {
  padding: var(--space-md) var(--space-2xl);
  font-size: 1.125rem;
}

.btn-sm {
  padding: var(--space-xs) var(--space-md);
  font-size: 0.875rem;
}

/* 卡片系统 */
.card {
  background: var(--color-surface);
  border-radius: var(--radius-xl);
  box-shadow: var(--shadow-sm);
  border: 1px solid var(--color-border);
  transition: all var(--transition-normal);
  overflow: hidden;
}

.card:hover {
  transform: translateY(-4px);
  box-shadow: var(--shadow-lg);
}

.card-body {
  padding: var(--space-xl);
}

/* 标题系统 */
h1, h2, h3, h4, h5, h6 {
  font-weight: 700;
  line-height: 1.2;
  color: var(--color-text-primary);
}

h1 { font-size: 3rem; margin-bottom: var(--space-lg); }
h2 { font-size: 2.25rem; margin-bottom: var(--space-md); }
h3 { font-size: 1.5rem; margin-bottom: var(--space-sm); }
h4 { font-size: 1.25rem; margin-bottom: var(--space-sm); }

.section-header {
  text-align: center;
  margin-bottom: var(--space-3xl);
}

.section-title {
  font-size: 2.5rem;
  font-weight: 700;
  color: var(--color-text-primary);
  margin-bottom: var(--space-md);
  position: relative;
  display: inline-block;
}

.section-title::after {
  content: '';
  display: block;
  width: 60px;
  height: 4px;
  background: var(--color-primary-gradient);
  margin: var(--space-md) auto 0;
  border-radius: var(--radius-full);
}

.section-subtitle {
  font-size: 1rem;
  color: var(--color-text-muted);
  letter-spacing: 0.15em;
  text-transform: uppercase;
  font-weight: 600;
}

/* 网格系统 */
.grid {
  display: grid;
  gap: var(--space-xl);
}

.grid-2 { grid-template-columns: repeat(auto-fit, minmax(280px, 1fr)); }
.grid-3 { grid-template-columns: repeat(auto-fit, minmax(300px, 1fr)); }
.grid-4 { grid-template-columns: repeat(auto-fit, minmax(250px, 1fr)); }

/* 动画 */
@keyframes fadeInUp {
  from {
    opacity: 0;
    transform: translateY(30px);
  }
  to {
    opacity: 1;
    transform: translateY(0);
  }
}

@keyframes slideInLeft {
  from {
    opacity: 0;
    transform: translateX(-50px);
  }
  to {
    opacity: 1;
    transform: translateX(0);
  }
}

@keyframes slideInRight {
  from {
    opacity: 0;
    transform: translateX(50px);
  }
  to {
    opacity: 1;
    transform: translateX(0);
  }
}

@keyframes scaleIn {
  from {
    opacity: 0;
    transform: scale(0.9);
  }
  to {
    opacity: 1;
    transform: scale(1);
  }
}

.animate-fade-in { animation: fadeInUp 0.6s ease-out forwards; }
.animate-slide-left { animation: slideInLeft 0.5s ease-out forwards; }
.animate-slide-right { animation: slideInRight 0.5s ease-out forwards; }
.animate-scale-in { animation: scaleIn 0.4s ease-out forwards; }

.delay-100 { animation-delay: 100ms; }
.delay-200 { animation-delay: 200ms; }
.delay-300 { animation-delay: 300ms; }
.delay-400 { animation-delay: 400ms; }
.delay-500 { animation-delay: 500ms; }

/* 响应式 */
@media (max-width: 768px) {
  h1 { font-size: 2rem; }
  h2 { font-size: 1.75rem; }
  h3 { font-size: 1.25rem; }
  
  .section-title { font-size: 2rem; }
  
  .grid-2, .grid-3, .grid-4 {
    grid-template-columns: 1fr;
  }
  
  .container {
    padding: 0 var(--space-md);
  }
}