/* =========================================================
   基础重置 + 排版 · 宋体高级版
   ========================================================= */

@import url('https://fonts.googleapis.com/css2?family=Noto+Serif+SC:wght@300;400;500;600;700&display=swap');

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

html {
  scroll-behavior: smooth;
  -webkit-text-size-adjust: 100%;
  -webkit-tap-highlight-color: transparent;
}

body {
  font-family: var(--font-serif);
  font-size: var(--font-size-base);
  font-weight: var(--font-weight-light);
  line-height: var(--line-height-normal);
  color: var(--color-text-primary);
  background-color: var(--color-bg-primary);
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
  letter-spacing: 0.02em;
}

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

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

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

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

input,
select,
textarea {
  font-family: var(--font-sans);
  font-size: inherit;
}

ul,
ol {
  list-style: none;
}

h1, h2, h3, h4, h5, h6 {
  font-family: var(--font-serif);
  font-weight: var(--font-weight-normal);
  line-height: var(--line-height-tight);
  letter-spacing: 0.04em;
}

/* === 工具类 === */
.text-center { text-align: center; }
.text-left { text-align: left; }
.text-right { text-align: right; }

.font-sans { font-family: var(--font-sans); }
.font-serif { font-family: var(--font-serif); }

.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;
}

.hidden {
  display: none !important;
}