/* ===========================================================
   base.css — reset + 全局基础样式
   =========================================================== */

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

html {
  -webkit-text-size-adjust: 100%;
  text-size-adjust: 100%;
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
  scroll-behavior: smooth;
  font-feature-settings: "kern", "liga", "calt";
}

body {
  font-family: var(--font-sans);
  font-size: var(--fs-body);
  font-weight: var(--fw-regular);
  line-height: var(--lh-body);
  color: var(--text-primary);
  background-color: var(--bg-base);
  letter-spacing: var(--ls-normal);
  min-height: 100vh;
  overflow-x: hidden;
  text-rendering: optimizeLegibility;
}

/* 英文模式下数字与英文字间距收紧 */
html[lang="en"] body {
  letter-spacing: var(--ls-tight);
}

h1, h2, h3, h4, h5, h6 {
  font-family: var(--font-display);
  font-weight: var(--fw-semibold);
  line-height: var(--lh-heading);
  letter-spacing: var(--ls-tight);
  color: var(--text-primary);
}

p {
  line-height: var(--lh-body);
  color: var(--text-secondary);
}

a {
  color: var(--accent);
  text-decoration: none;
  transition: color var(--dur-fast) var(--ease-out);
}
a:hover { color: var(--accent-strong); }

button {
  font-family: inherit;
  font-size: inherit;
  color: inherit;
  background: none;
  border: none;
  cursor: pointer;
  -webkit-tap-highlight-color: transparent;
}

input, textarea {
  font-family: inherit;
  font-size: inherit;
  color: inherit;
}

ul, ol { list-style: none; }

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

/* 滚动条美化（WebKit） */
::-webkit-scrollbar {
  width: 10px;
  height: 10px;
}
::-webkit-scrollbar-track {
  background: transparent;
}
::-webkit-scrollbar-thumb {
  background: rgba(var(--shadow-rgb), 0.18);
  border-radius: var(--r-pill);
  border: 2px solid transparent;
  background-clip: padding-box;
}
::-webkit-scrollbar-thumb:hover {
  background: rgba(var(--shadow-rgb), 0.30);
  background-clip: padding-box;
  border: 2px solid transparent;
}

/* 选中态 */
::selection {
  background: var(--accent-soft);
  color: var(--text-primary);
}

/* 焦点可见性 */
:focus-visible {
  outline: 2px solid var(--accent);
  outline-offset: 2px;
  border-radius: 4px;
}

/* 隐藏类 */
.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; }

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

/* 通用文本工具 */
.text-mono { font-family: var(--font-mono); }
.text-secondary { color: var(--text-secondary); }
.text-tertiary { color: var(--text-tertiary); }
.text-ticker { font-family: var(--font-mono); letter-spacing: var(--ls-ticker); }

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