/* ==========================================================================
   文件一：variables.css - 颜色变量、全局基础、头部与导航
   ========================================================================== */

/* ============================================================
 * 1. 颜色变量配置中心
 * ============================================================ */
:root {
  --bg-color:     #f6f8fa;   
  --text-color:   #24292f;   
  --card-bg:      #eaeef2;   
  --border-color: #d0d7de;   
  --accent-color: #0969da;   

  --table-border:    #d0d7de; 
  --table-header-bg: #f6f8fa; 
  --table-hover-bg:  #eaeef2; 
  --code-bg:         #f6f8fa; 
  --code-text:       #24292f; 
}

html[data-mode="dark"] {
  --bg-color:     #22272e;   
  --text-color:   #adbac7;   
  --card-bg:      #2d333b;   
  --border-color: #444c56;   
  --accent-color: #539bf5;   

  --table-border:    #444c56; 
  --table-header-bg: #2d333b; 
  --table-hover-bg:  #373e47; 
  --code-bg:         #2d333b; 
  --code-text:       #adbac7; 
}

/* ============================================================
 * 2. 全局基础样式
 * ============================================================ */
html {
  -webkit-tap-highlight-color: transparent;
}

#main, #footer {
  transition: opacity 0.35s ease, transform 0.35s ease;
  will-change: opacity, transform;
}
html.is-animating #main, #footer {
  opacity: 0;
  transform: translateY(20px);
}
html.is-leaving #main, #footer {
  opacity: 1;
  transform: translateY(0);
}

body {
  background-color: var(--bg-color);
  color: var(--text-color);
  font-family: "Droid Serif", Georgia, "Times New Roman", "PingFang SC", "Hiragino Sans GB", "Source Han Sans CN", "WenQuanYi Micro Hei","Microsoft Yahei", serif;
  font-size: 100%;
  transition: background-color 0.3s ease, color 0.3s ease;
}

a { color: var(--accent-color); text-decoration: none; }
a:hover, a:active { color: var(--text-color); }

button {
  -webkit-appearance: button;
  background-color: var(--accent-color);
  border: none;
  color: #ffffff;
  padding: 5px 15px;
  text-align: center;
  text-decoration: none;
  display: inline-block;
  border-radius: 6px;
}

.meta-tags {
  background: var(--accent-color);
  color: #fff;
  font-size: 0.65rem;
  padding: 2px 8px;
  border-radius: 4px;
  margin-left: 8px;
}

.logout-form { display: inline; margin: 0; padding: 0; }
.logout-form button { padding: 0; border: 0; background: transparent; color: var(--accent-color); font: inherit; cursor: pointer; }
.logout-form button:hover, .logout-form button:active { color: var(--text-color); }

/* ============================================================
 * 3. 头部导航与搜索
 * ============================================================ */
#header { padding-top: 35px; border-bottom: 1px solid var(--border-color); }
#logo { color: var(--text-color); font-size: 2.5em; }
#logo img { max-height: 64px; }
.description { margin: .5em 0 0; color: var(--text-color); opacity: 0.6; font-style: italic; }

#nav-menu { margin: 25px 0 0; padding: 0; }
#nav-menu a {
  display: block;
  margin-right: -1px;
  padding: 0 20px;
  border: 1px solid var(--border-color);
  border-bottom: none;
  height: 32px;
  line-height: 32px;
  color: var(--text-color);
  background: var(--bg-color);
  float: left;
  transition: background 0.2s ease, color 0.2s ease;
}
#nav-menu a:hover { background: var(--card-bg); color: var(--accent-color); }
#nav-menu a.current { background: var(--card-bg); color: var(--accent-color); font-weight: 700; border-color: var(--accent-color); }

#search { position: relative; margin-top: 15px; }
#search input { padding-right: 30px; background: var(--bg-color); color: var(--text-color); border: 1px solid var(--border-color); }
#search button {
  position: absolute;
  right: 4px;
  top: 2px;
  border: none;
  padding: 0;
  width: 24px;
  height: 24px;
  background: transparent;
  cursor: pointer;
  direction: ltr;
  font-size: 0;
  color: transparent;
}
#search button:before { content: "\1F50D"; font-size: 14px; color: var(--text-color); opacity: 0.6; }