/* ==========================================================================
   初始化样式 | Base / Reset
   依赖: variable.css（颜色等变量）
   ========================================================================== */

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

/* ---------- 文档基础 ---------- */
html {
  -webkit-text-size-adjust: 100%;
  -webkit-tap-highlight-color: transparent;
  /* 主题主色为 #1c74bb，浏览器地址栏/主题色保持一致 */
  accent-color: var(--color-primary);
}

body {
  min-width: 320px;
  min-height: 100vh;
  /* 字体说明：仅使用系统自带中文字体栈，不嵌入任何收费字体文件，避免商用版权风险 */
  font-family: "Microsoft YaHei", "PingFang SC", "Hiragino Sans GB", "Noto Sans SC", "Source Han Sans SC", "WenQuanYi Micro Hei", sans-serif;
  font-size: 16px;
  line-height: 1.6;
  color: var(--color-text-regular);
  background-color: var(--color-bg-page);
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
  text-rendering: optimizeLegibility;
}

/* ---------- 媒体元素 ---------- */
img,
picture,
video,
svg,
canvas {
  display: block;
  max-width: 100%;
  height: auto;
}

audio,
video,
canvas {
  vertical-align: middle;
}

/* ---------- 链接 ---------- */
a {
  color: var(--color-primary);
  text-decoration: none;
  background-color: transparent;
  transition: color 0.25s ease;
}

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

a:active {
  color: var(--color-primary-darker);
}

/* ---------- 标题 ---------- */
h1, h2, h3, h4, h5, h6 {
  font-weight: 600;
  line-height: 1.3;
  color: var(--color-text-primary);
}

h1 { font-size: 2rem; }
h2 { font-size: 1.6rem; }
h3 { font-size: 1.35rem; }
h4 { font-size: 1.15rem; }
h5 { font-size: 1rem; }
h6 { font-size: 0.95rem; }

/* ---------- 段落/列表 ---------- */
p {
  margin: 0 0 1em;
}

ol,
ul {
  list-style: none;
}

/* ---------- 表单 ---------- */
button,
input,
select,
textarea {
  font: inherit;
  color: inherit;
  background-color: transparent;
  border: none;
  outline: none;
}

button {
  cursor: pointer;
}

textarea {
  resize: vertical;
}

/* ---------- 选择 ---------- */
::selection {
  color: var(--color-text-inverse);
  background-color: var(--color-primary);
}

/* ---------- 滚动条（WebKit） ---------- */
::-webkit-scrollbar {
  width: 8px;
  height: 8px;
}

::-webkit-scrollbar-track {
  background-color: var(--color-bg-gray);
}

::-webkit-scrollbar-thumb {
  border-radius: 4px;
  background-color: var(--color-primary-light);
}

::-webkit-scrollbar-thumb:hover {
  background-color: var(--color-primary);
}

/* ---------- 工具类 ---------- */
.text-primary { color: var(--color-primary) !important; }
.text-secondary { color: var(--color-text-secondary) !important; }
.text-muted { color: var(--color-text-muted) !important; }
.text-inverse { color: var(--color-text-inverse) !important; }

.bg-white { background-color: var(--color-bg-white) !important; }
.bg-gray { background-color: var(--color-bg-gray) !important; }

.text-center { text-align: center !important; }
.text-left { text-align: left !important; }
.text-right { text-align: right !important; }

.hidden { display: none !important; }

.clearfix::after {
  display: table;
  content: "";
  clear: both;
}

/* ---------- 无障碍：仅读屏显示 ---------- */
.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;
}