:root {
  --color-primary: #1A5FFE;
  --color-primary-dark: #0E4FCC;
  --color-primary-light: #4D85FE;
  --color-primary-bg: #E8F0FE;
  --color-accent: #FF6B35;
  --color-accent-dark: #E55A2B;
  --color-accent-light: #FF8F66;
  --color-accent-bg: #FFF0E8;
  --color-text-primary: #1A1A2E;
  --color-text-secondary: #4A4A6A;
  --color-text-light: #8A8AA0;
  --color-text-white: #FFFFFF;
  --color-bg-primary: #FFFFFF;
  --color-bg-secondary: #F5F7FA;
  --color-bg-tertiary: #EEF1F6;
  --color-border: #E0E4EA;
  --color-border-light: #F0F2F5;
  --color-success: #00C48C;
  --color-warning: #FFB800;
  --color-error: #FF4757;
  --font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei", "Helvetica Neue", Arial, sans-serif;
  --font-size-xs: 0.75rem;
  --font-size-sm: 0.875rem;
  --font-size-base: 1rem;
  --font-size-md: 1.125rem;
  --font-size-lg: 1.25rem;
  --font-size-xl: 1.5rem;
  --font-size-2xl: 2rem;
  --font-size-3xl: 2.5rem;
  --font-size-4xl: 3rem;
  --font-weight-normal: 400;
  --font-weight-medium: 500;
  --font-weight-semibold: 600;
  --font-weight-bold: 700;
  --spacing-xs: 0.25rem;
  --spacing-sm: 0.5rem;
  --spacing-md: 1rem;
  --spacing-lg: 1.5rem;
  --spacing-xl: 2rem;
  --spacing-2xl: 3rem;
  --spacing-3xl: 4rem;
  --radius-sm: 4px;
  --radius-md: 8px;
  --radius-lg: 12px;
  --radius-xl: 16px;
  --radius-full: 50%;
  --shadow-sm: 0 1px 3px rgba(0,0,0,0.08);
  --shadow-md: 0 4px 12px rgba(0,0,0,0.1);
  --shadow-lg: 0 8px 24px rgba(0,0,0,0.12);
  --shadow-xl: 0 12px 48px rgba(0,0,0,0.15);
  --transition-fast: 150ms ease;
  --transition-normal: 300ms ease;
  --transition-slow: 500ms ease;
  --z-dropdown: 100;
  --z-sticky: 200;
  --z-modal: 1000;
  --z-toast: 1100;
}

*, *::before, *::after {
  margin: 0;
  padding: 0;
  box-sizing: border-box;
}

html {
  font-size: 14px;
  scroll-behavior: smooth;
  -webkit-text-size-adjust: 100%;
}

@media (min-width: 768px) {
  html { font-size: 15px; }
}

@media (min-width: 1024px) {
  html { font-size: 16px; }
}

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

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

a:hover {
  color: var(--color-primary-dark);
}

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

ul, ol {
  list-style: none;
}

button, input, select, textarea {
  font-family: inherit;
  font-size: inherit;
  color: inherit;
  border: none;
  outline: none;
  background: none;
}

button {
  cursor: pointer;
}

::selection {
  background-color: var(--color-primary);
  color: var(--color-text-white);
}