/* ==========================================================================
   Reset & Base — 优锐安官网
   ========================================================================== */

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

html {
  font-size: 16px;
  -webkit-text-size-adjust: 100%;
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
  scroll-behavior: smooth;
}

body {
  font-family: var(--font-sans);
  font-size: 15px;
  line-height: 1.65;
  color: var(--color-text);
  background: var(--color-bg);
  overflow-x: hidden;
}

img, picture, video, canvas, svg {
  display: block;
  max-width: 100%;
  height: auto;
}

a {
  color: inherit;
  text-decoration: none;
  transition: color 0.2s ease;
}

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

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

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

ul, ol {
  list-style: none;
}

h1, h2, h3, h4, h5, h6 {
  line-height: 1.3;
  font-weight: 600;
}

h1 { font-size: 2.25rem; }  /* 36px */
h2 { font-size: 1.875rem; } /* 30px */
h3 { font-size: 1.5rem; }   /* 24px */
h4 { font-size: 1.25rem; }  /* 20px */
h5 { font-size: 1.125rem; } /* 18px */
h6 { font-size: 1rem; }     /* 16px */

p { margin-bottom: 1em; }
p:last-child { margin-bottom: 0; }

::selection {
  background: var(--color-primary);
  color: #fff;
}

/* 无障碍：隐藏但屏幕阅读器可读 */
.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;
}