/* ===================================
   Fanli OEM Partnership Homepage
   Main CSS File - Design System
   =================================== */

/* CSS Custom Properties (Design Tokens) */
:root {
  /* ===== Brand Colors ===== */
  --fanli-primary: #2772fa;           /* Fanli Blue */
  --fanli-primary-light: #4f8bfb;     /* Light Blue */
  --fanli-primary-dark: #1e5af8;      /* Dark Blue */
  --fanli-secondary: #660abd;         /* Deep Purple */
  --fanli-secondary-light: #8b2de0;   /* Light Purple */
  --fanli-secondary-dark: #4a0891;    /* Dark Purple */
  
  /* ===== Neutral Colors ===== */
  --fanli-white: #ffffff;
  --fanli-black: #000000;
  --fanli-gray-50: #f8fafc;
  --fanli-gray-100: #f1f5f9;
  --fanli-gray-200: #e2e8f0;
  --fanli-gray-300: #cbd5e1;
  --fanli-gray-400: #94a3b8;
  --fanli-gray-500: #64748b;
  --fanli-gray-600: #475569;
  --fanli-gray-700: #334155;
  --fanli-gray-800: #1e293b;
  --fanli-gray-900: #0f172a;
  
  /* ===== Accent Colors ===== */
  --fanli-success: #10b981;
  --fanli-success-light: #34d399;
  --fanli-warning: #f59e0b;
  --fanli-warning-light: #fbbf24;
  --fanli-error: #ef4444;
  --fanli-error-light: #f87171;
  --fanli-info: #3b82f6;
  --fanli-info-light: #60a5fa;
  
  /* ===== Background Colors ===== */
  --fanli-bg-primary: var(--fanli-white);
  --fanli-bg-secondary: var(--fanli-gray-50);
  --fanli-bg-tertiary: var(--fanli-gray-100);
  --fanli-bg-dark: var(--fanli-gray-900);
  --fanli-bg-hero: linear-gradient(135deg, var(--fanli-gray-900) 0%, var(--fanli-gray-800) 100%);
  --fanli-bg-feature: linear-gradient(135deg, var(--fanli-primary) 0%, var(--fanli-secondary) 100%);
  
  /* ===== Text Colors ===== */
  --fanli-text-primary: var(--fanli-gray-900);
  --fanli-text-secondary: var(--fanli-gray-600);
  --fanli-text-tertiary: var(--fanli-gray-500);
  --fanli-text-inverse: var(--fanli-white);
  --fanli-text-brand: var(--fanli-primary);
  
  /* ===== Typography ===== */
  --fanli-font-family-primary: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, sans-serif;
  --fanli-font-family-display: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, sans-serif;
  --fanli-font-family-mono: 'SF Mono', Monaco, 'Cascadia Code', 'Roboto Mono', Consolas, monospace;
  
  /* Font Sizes */
  --fanli-font-size-xs: 0.75rem;      /* 12px */
  --fanli-font-size-sm: 0.875rem;     /* 14px */
  --fanli-font-size-base: 1rem;       /* 16px */
  --fanli-font-size-lg: 1.125rem;     /* 18px */
  --fanli-font-size-xl: 1.25rem;      /* 20px */
  --fanli-font-size-2xl: 1.5rem;      /* 24px */
  --fanli-font-size-3xl: 1.875rem;    /* 30px */
  --fanli-font-size-4xl: 2.25rem;     /* 36px */
  --fanli-font-size-5xl: 3rem;        /* 48px */
  --fanli-font-size-6xl: 3.75rem;     /* 60px */
  --fanli-font-size-7xl: 4.5rem;      /* 72px */
  
  /* Font Weights */
  --fanli-font-weight-light: 300;
  --fanli-font-weight-normal: 400;
  --fanli-font-weight-medium: 500;
  --fanli-font-weight-semibold: 600;
  --fanli-font-weight-bold: 700;
  --fanli-font-weight-extrabold: 800;
  
  /* Line Heights */
  --fanli-line-height-tight: 1.25;
  --fanli-line-height-snug: 1.375;
  --fanli-line-height-normal: 1.5;
  --fanli-line-height-relaxed: 1.625;
  --fanli-line-height-loose: 2;
  
  /* ===== Spacing System ===== */
  --fanli-space-0: 0;
  --fanli-space-1: 0.25rem;           /* 4px */
  --fanli-space-2: 0.5rem;            /* 8px */
  --fanli-space-3: 0.75rem;           /* 12px */
  --fanli-space-4: 1rem;              /* 16px */
  --fanli-space-5: 1.25rem;           /* 20px */
  --fanli-space-6: 1.5rem;            /* 24px */
  --fanli-space-8: 2rem;              /* 32px */
  --fanli-space-10: 2.5rem;           /* 40px */
  --fanli-space-12: 3rem;             /* 48px */
  --fanli-space-16: 4rem;             /* 64px */
  --fanli-space-20: 5rem;             /* 80px */
  --fanli-space-24: 6rem;             /* 96px */
  --fanli-space-32: 8rem;             /* 128px */
  --fanli-space-40: 10rem;            /* 160px */
  --fanli-space-48: 12rem;            /* 192px */
  --fanli-space-56: 14rem;            /* 224px */
  --fanli-space-64: 16rem;            /* 256px */
  
  /* ===== Border Radius ===== */
  --fanli-radius-none: 0;
  --fanli-radius-sm: 0.125rem;        /* 2px */
  --fanli-radius-base: 0.25rem;       /* 4px */
  --fanli-radius-md: 0.375rem;        /* 6px */
  --fanli-radius-lg: 0.5rem;          /* 8px */
  --fanli-radius-xl: 0.75rem;         /* 12px */
  --fanli-radius-2xl: 1rem;           /* 16px */
  --fanli-radius-3xl: 1.5rem;         /* 24px */
  --fanli-radius-full: 9999px;
  
  /* ===== Shadows ===== */
  --fanli-shadow-sm: 0 1px 2px 0 rgba(0, 0, 0, 0.05);
  --fanli-shadow-base: 0 1px 3px 0 rgba(0, 0, 0, 0.1), 0 1px 2px 0 rgba(0, 0, 0, 0.06);
  --fanli-shadow-md: 0 4px 6px -1px rgba(0, 0, 0, 0.1), 0 2px 4px -1px rgba(0, 0, 0, 0.06);
  --fanli-shadow-lg: 0 10px 15px -3px rgba(0, 0, 0, 0.1), 0 4px 6px -2px rgba(0, 0, 0, 0.05);
  --fanli-shadow-xl: 0 20px 25px -5px rgba(0, 0, 0, 0.1), 0 10px 10px -5px rgba(0, 0, 0, 0.04);
  --fanli-shadow-2xl: 0 25px 50px -12px rgba(0, 0, 0, 0.25);
  --fanli-shadow-inner: inset 0 2px 4px 0 rgba(0, 0, 0, 0.06);
  --fanli-shadow-brand: 0 10px 25px -3px rgba(39, 114, 250, 0.3), 0 4px 6px -2px rgba(39, 114, 250, 0.1);
  
  /* ===== Transitions ===== */
  --fanli-transition-fast: 150ms ease-in-out;
  --fanli-transition-base: 250ms ease-in-out;
  --fanli-transition-slow: 350ms ease-in-out;
  --fanli-transition-bounce: 0.3s cubic-bezier(0.68, -0.55, 0.265, 1.55);
  
  /* ===== Z-Index Scale ===== */
  --fanli-z-dropdown: 1000;
  --fanli-z-sticky: 1020;
  --fanli-z-fixed: 1030;
  --fanli-z-modal-backdrop: 1040;
  --fanli-z-modal: 1050;
  --fanli-z-popover: 1060;
  --fanli-z-tooltip: 1070;
  --fanli-z-toast: 1080;
  
  /* ===== Responsive Breakpoints ===== */
  --fanli-breakpoint-sm: 640px;       /* Small devices */
  --fanli-breakpoint-md: 768px;       /* Medium devices */
  --fanli-breakpoint-lg: 1024px;      /* Large devices */
  --fanli-breakpoint-xl: 1280px;      /* Extra large devices */
  --fanli-breakpoint-2xl: 1536px;     /* 2X large devices */
  
  /* ===== Container Widths ===== */
  --fanli-container-sm: 640px;
  --fanli-container-md: 768px;
  --fanli-container-lg: 1024px;
  --fanli-container-xl: 1280px;
  --fanli-container-2xl: 1400px;
  --fanli-container-full: 100%;
  
  /* ===== Animation Durations ===== */
  --fanli-duration-75: 75ms;
  --fanli-duration-100: 100ms;
  --fanli-duration-150: 150ms;
  --fanli-duration-200: 200ms;
  --fanli-duration-300: 300ms;
  --fanli-duration-500: 500ms;
  --fanli-duration-700: 700ms;
  --fanli-duration-1000: 1000ms;
  
  /* ===== Animation Timing Functions ===== */
  --fanli-ease-linear: linear;
  --fanli-ease-in: cubic-bezier(0.4, 0, 1, 1);
  --fanli-ease-out: cubic-bezier(0, 0, 0.2, 1);
  --fanli-ease-in-out: cubic-bezier(0.4, 0, 0.2, 1);
  --fanli-ease-bounce: cubic-bezier(0.68, -0.55, 0.265, 1.55);
  --fanli-ease-elastic: cubic-bezier(0.175, 0.885, 0.32, 1.275);
}

/* ===== Global Reset & Base Styles ===== */
*,
*::before,
*::after {
  box-sizing: border-box;
  margin: 0;
  padding: 0;
}

html {
  scroll-behavior: smooth;
  font-size: 16px;
  line-height: 1.5;
}

body {
  font-family: var(--fanli-font-family-primary);
  font-size: var(--fanli-font-size-base);
  font-weight: var(--fanli-font-weight-normal);
  line-height: var(--fanli-line-height-normal);
  color: var(--fanli-text-primary);
  background-color: var(--fanli-bg-primary);
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
  text-rendering: optimizeLegibility;
}

/* ===== Typography Base ===== */
h1, h2, h3, h4, h5, h6 {
  font-family: var(--fanli-font-family-display);
  font-weight: var(--fanli-font-weight-bold);
  line-height: var(--fanli-line-height-tight);
  color: var(--fanli-text-primary);
  margin-bottom: var(--fanli-space-4);
}

h1 {
  font-size: var(--fanli-font-size-5xl);
  font-weight: var(--fanli-font-weight-extrabold);
}

h2 {
  font-size: var(--fanli-font-size-4xl);
  font-weight: var(--fanli-font-weight-bold);
}

h3 {
  font-size: var(--fanli-font-size-3xl);
  font-weight: var(--fanli-font-weight-bold);
}

h4 {
  font-size: var(--fanli-font-size-2xl);
  font-weight: var(--fanli-font-weight-semibold);
}

h5 {
  font-size: var(--fanli-font-size-xl);
  font-weight: var(--fanli-font-weight-semibold);
}

h6 {
  font-size: var(--fanli-font-size-lg);
  font-weight: var(--fanli-font-weight-semibold);
}

p {
  margin-bottom: var(--fanli-space-4);
  color: var(--fanli-text-secondary);
  line-height: var(--fanli-line-height-relaxed);
}

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

a:hover {
  color: var(--fanli-primary-dark);
  text-decoration: underline;
}

/* ===== Utility Classes ===== */
.fanli-container {
  width: 100%;
  max-width: var(--fanli-container-xl);
  margin: 0 auto;
  padding: 0 var(--fanli-space-4);
}

.fanli-container-full {
  width: 100%;
  padding: 0 var(--fanli-space-4);
}

.fanli-text-center {
  text-align: center;
}

.fanli-text-left {
  text-align: left;
}

.fanli-text-right {
  text-align: right;
}

.fanli-sr-only {
  position: absolute;
  width: 1px;
  height: 1px;
  padding: 0;
  margin: -1px;
  overflow: hidden;
  clip: rect(0, 0, 0, 0);
  white-space: nowrap;
  border: 0;
}

/* ===== Responsive Typography ===== */
@media (max-width: 768px) {
  :root {
    --fanli-font-size-5xl: 2.5rem;    /* 40px */
    --fanli-font-size-4xl: 2rem;      /* 32px */
    --fanli-font-size-3xl: 1.75rem;   /* 28px */
  }
  
  .fanli-container {
    padding: 0 var(--fanli-space-4);
  }
}

@media (max-width: 480px) {
  :root {
    --fanli-font-size-5xl: 2rem;      /* 32px */
    --fanli-font-size-4xl: 1.75rem;   /* 28px */
    --fanli-font-size-3xl: 1.5rem;    /* 24px */
  }
  
  .fanli-container {
    padding: 0 var(--fanli-space-3);
  }
}

/* ===== Dark Mode Support (Optional) ===== */
@media (prefers-color-scheme: dark) {
  :root {
    --fanli-bg-primary: var(--fanli-gray-900);
    --fanli-bg-secondary: var(--fanli-gray-800);
    --fanli-bg-tertiary: var(--fanli-gray-700);
    --fanli-text-primary: var(--fanli-white);
    --fanli-text-secondary: var(--fanli-gray-300);
    --fanli-text-tertiary: var(--fanli-gray-400);
  }
}

/* ===== Accessibility ===== */
@media (prefers-reduced-motion: reduce) {
  *,
  *::before,
  *::after {
    animation-duration: 0.01ms !important;
    animation-iteration-count: 1 !important;
    transition-duration: 0.01ms !important;
    scroll-behavior: auto !important;
  }
}

/* Focus styles for keyboard navigation */
:focus {
  outline: 2px solid var(--fanli-primary);
  outline-offset: 2px;
}

:focus:not(:focus-visible) {
  outline: none;
}

:focus-visible {
  outline: 2px solid var(--fanli-primary);
  outline-offset: 2px;
}