/* ============================================================
   SINUMERIK CNC 调试教程站 · 全站样式
   布局参考 runoob，配色采用西门子工业青绿
   ============================================================ */

:root {
  --primary: #009999;
  --primary-dark: #007f7f;
  --primary-light: #e6f5f5;
  --navy: #132a2a;
  --navy-deep: #0c1e1e;
  --ink: #2b3133;
  --muted: #7a8385;
  --line: #e3e9e9;
  --bg: #f5f8f8;
  --card: #ffffff;
  --warn-bg: #fff8e1;
  --warn-line: #ffd54f;
  --danger-bg: #fdecec;
  --danger-line: #ef9a9a;
  --ok-bg: #e8f7ee;
  --ok-line: #81c784;
  --code-bg: #0f1b1b;
}

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

html { scroll-behavior: smooth; }

body {
  font-family: "Segoe UI", "PingFang SC", "Microsoft YaHei", "Helvetica Neue", system-ui, sans-serif;
  color: var(--ink);
  background: var(--bg);
  font-size: 15px;
  line-height: 1.75;
}

a { color: var(--primary-dark); text-decoration: none; }
a:hover { text-decoration: underline; }

/* ============ 顶部导航 ============ */
.site-header {
  background: linear-gradient(180deg, var(--navy) 0%, var(--navy-deep) 100%);
  border-bottom: 3px solid var(--primary);
  position: sticky;
  top: 0;
  z-index: 100;
  box-shadow: 0 2px 10px rgba(0, 0, 0, 0.25);
}
.header-inner {
  max-width: 1200px;
  margin: 0 auto;
  padding: 0 20px;
  display: flex;
  align-items: center;
  height: 58px;
  gap: 26px;
}
.logo { display: flex; align-items: center; gap: 10px; color: #fff; }
.logo:hover { text-decoration: none; }
.logo-badge {
  width: 34px; height: 34px;
  background: var(--primary);
  border-radius: 7px;
  display: flex; align-items: center; justify-content: center;
  font-weight: 800; font-size: 16px; color: #fff;
  box-shadow: 0 0 12px rgba(0, 153, 153, 0.5);
}
.logo-text { font-weight: 700; font-size: 17px; letter-spacing: 1px; }
.logo-sub { font-size: 11px; color: rgba(255, 255, 255, 0.55); letter-spacing: 2px; display: block; margin-top: -2px; }

.site-nav { display: flex; gap: 2px; flex: 1; flex-wrap: wrap; }
.site-nav a {
  color: rgba(255, 255, 255, 0.85);
  padding: 6px 12px;
  font-size: 14px;
  border-radius: 6px;
  white-space: nowrap;
}
.site-nav a:hover { color: #fff; background: rgba(255, 255, 255, 0.08); text-decoration: none; }
.site-nav a.active { color: #fff; background: var(--primary); font-weight: 600; }

/* ============ 通用布局 ============ */
.page {
  max-width: 1200px;
  margin: 0 auto;
  padding: 26px 20px 60px;
  display: flex;
  gap: 26px;
  align-items: flex-start;
}

/* 左侧目录栏 */
.sidebar {
  width: 240px;
  flex-shrink: 0;
  position: sticky;
  top: 76px;
  background: var(--card);
  border: 1px solid var(--line);
  border-radius: 10px;
  padding: 14px 0;
  max-height: calc(100vh - 100px);
  overflow-y: auto;
}
.sidebar-title {
  font-size: 12px;
  color: var(--muted);
  letter-spacing: 3px;
  padding: 4px 18px 10px;
  border-bottom: 1px solid var(--line);
  margin-bottom: 8px;
  font-weight: 600;
}
.sidebar a {
  display: block;
  padding: 7px 18px;
  font-size: 14px;
  color: var(--ink);
  border-left: 3px solid transparent;
}
.sidebar a:hover { background: var(--primary-light); text-decoration: none; }
.sidebar a.active { color: var(--primary-dark); border-left-color: var(--primary); background: var(--primary-light); font-weight: 600; }
.sidebar .grp { font-size: 12px; color: var(--muted); padding: 12px 18px 4px; letter-spacing: 1px; }
.sidebar .grp + a { padding-top: 4px; }

/* 内容区 */
.content { flex: 1; min-width: 0; background: var(--card); border: 1px solid var(--line); border-radius: 10px; padding: 30px 36px; }

.breadcrumb { font-size: 13px; color: var(--muted); margin-bottom: 14px; }
.breadcrumb a { color: var(--muted); }
.breadcrumb a:hover { color: var(--primary-dark); }
.breadcrumb .sep { margin: 0 6px; color: #c2caca; }

h1 { font-size: 28px; color: var(--navy); line-height: 1.4; margin-bottom: 6px; }
h2 { font-size: 22px; color: var(--navy); margin: 36px 0 14px; padding-bottom: 8px; border-bottom: 1px solid var(--line); scroll-margin-top: 80px; }
h2::before { content: "▍"; color: var(--primary); margin-right: 6px; }
h3 { font-size: 17px; color: var(--primary-dark); margin: 22px 0 10px; }
p { margin: 10px 0; }
ul, ol { margin: 10px 0 10px 22px; }
li { margin: 4px 0; }
strong { color: var(--navy); }
.lead { font-size: 16px; color: #566; }

/* 表格 */
table { width: 100%; border-collapse: collapse; margin: 14px 0; font-size: 14px; }
th { background: var(--primary-light); color: var(--navy); text-align: left; }
th, td { border: 1px solid var(--line); padding: 8px 12px; }
tr:nth-child(even) td { background: #fafcfc; }
.table-wrap { overflow-x: auto; }

/* 代码块 */
pre {
  background: var(--code-bg);
  color: #b8f2e6;
  padding: 14px 16px;
  border-radius: 8px;
  overflow-x: auto;
  font-family: "Consolas", "Courier New", monospace;
  font-size: 13px;
  line-height: 1.6;
  margin: 12px 0;
}
code { font-family: "Consolas", "Courier New", monospace; background: var(--primary-light); color: var(--primary-dark); padding: 1px 6px; border-radius: 4px; font-size: 13px; }
pre code { background: transparent; color: inherit; padding: 0; }

/* 提示框 */
.callout { border-left: 4px solid var(--primary); background: var(--primary-light); padding: 12px 16px; border-radius: 0 8px 8px 0; margin: 14px 0; font-size: 14px; }
.callout.warn { border-color: var(--warn-line); background: var(--warn-bg); }
.callout.danger { border-color: var(--danger-line); background: var(--danger-bg); }
.callout.ok { border-color: var(--ok-line); background: var(--ok-bg); }
.callout b { display: block; margin-bottom: 2px; }

/* ============ 首页 ============ */
.hero {
  background: linear-gradient(135deg, var(--navy) 0%, #0f4c4c 60%, #0c1e1e 100%);
  color: #fff;
  border-radius: 12px;
  padding: 44px 40px;
  margin-bottom: 26px;
  position: relative;
  overflow: hidden;
}
.hero::after {
  content: "CNC";
  position: absolute; right: -20px; bottom: -50px;
  font-size: 200px; font-weight: 900;
  color: rgba(255, 255, 255, 0.05);
  font-family: "Arial Black", sans-serif;
}
.hero h1 { color: #fff; font-size: 32px; }
.hero .tag { color: var(--primary); font-size: 15px; letter-spacing: 3px; margin-bottom: 6px; }
.hero p { color: rgba(255, 255, 255, 0.78); max-width: 640px; }
.hero .badges { margin-top: 18px; display: flex; gap: 10px; flex-wrap: wrap; }
.hero .badge { background: rgba(0, 153, 153, 0.25); border: 1px solid rgba(0, 153, 153, 0.6); color: #7fe3e3; padding: 4px 12px; border-radius: 20px; font-size: 12px; }

.section-title { display: flex; align-items: center; gap: 10px; margin: 30px 0 16px; }
.section-title h2 { margin: 0; border: none; }
.section-title h2::before { content: ""; }
.section-title .more { margin-left: auto; font-size: 13px; }

/* 教程分类卡片 */
.card-grid { display: grid; grid-template-columns: repeat(auto-fill, minmax(270px, 1fr)); gap: 16px; }
.card {
  background: var(--card);
  border: 1px solid var(--line);
  border-radius: 10px;
  padding: 18px 18px 14px;
  transition: transform 0.15s, box-shadow 0.15s, border-color 0.15s;
  display: block;
  color: var(--ink);
}
.card:hover { transform: translateY(-3px); box-shadow: 0 8px 22px rgba(0, 0, 0, 0.08); border-color: var(--primary); text-decoration: none; }
.card .card-tag { font-size: 12px; color: var(--primary-dark); background: var(--primary-light); border-radius: 4px; padding: 1px 8px; letter-spacing: 1px; display: inline-block; margin-bottom: 8px; font-weight: 600; }
.card h3 { font-size: 17px; color: var(--navy); margin: 0 0 6px; }
.card p { font-size: 13px; color: var(--muted); margin: 0; line-height: 1.6; }
.card .go { margin-top: 10px; font-size: 13px; color: var(--primary-dark); font-weight: 600; }

/* 页脚 */
.site-footer { background: var(--navy-deep); color: rgba(255, 255, 255, 0.6); padding: 26px 20px 30px; margin-top: 20px; }
.footer-inner { max-width: 1200px; margin: 0 auto; display: flex; justify-content: space-between; gap: 20px; flex-wrap: wrap; font-size: 13px; }
.footer-inner b { color: #fff; display: block; margin-bottom: 6px; font-size: 14px; }
.footer-inner ul { list-style: none; margin: 0; }
.footer-inner a { color: rgba(255, 255, 255, 0.6); }
.footer-inner a:hover { color: #7fe3e3; text-decoration: none; }

/* 响应式 */
@media (max-width: 900px) {
  .page { flex-direction: column; }
  .sidebar { width: 100%; position: static; max-height: none; }
  .content { padding: 20px 18px; }
  .site-nav { display: none; }
}