:root {
  --bg: #f7f8fa;
  --card: #ffffff;
  --text: #1f2329;
  --muted: #6b7280;
  --accent: #2563eb;
  --accent-soft: #eff6ff;
  --border: #e5e7eb;
  --code-bg: #f6f8fa;
  --warn-bg: #fffbeb;
  --warn-border: #f59e0b;
  --radius: 10px;
}
* { box-sizing: border-box; margin: 0; padding: 0; }
html { scroll-behavior: smooth; }
body {
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei", sans-serif;
  background: var(--bg);
  color: var(--text);
  line-height: 1.75;
  font-size: 15px;
}
a { color: var(--accent); text-decoration: none; }
a:hover { text-decoration: underline; }

/* ===== 顶栏 ===== */
.topbar {
  position: sticky; top: 0; z-index: 50;
  display: flex; align-items: center; gap: 12px;
  height: 56px; padding: 0 16px;
  background: var(--card); border-bottom: 1px solid var(--border);
}
.brand { font-weight: 700; font-size: 17px; color: var(--text); white-space: nowrap; }
.brand:hover { text-decoration: none; color: var(--accent); }
.menu-btn {
  display: none; border: 1px solid var(--border); background: var(--card);
  border-radius: 8px; width: 36px; height: 36px; font-size: 16px; cursor: pointer;
}
.search-wrap { position: relative; flex: 1; max-width: 420px; margin-left: auto; }
#searchInput {
  width: 100%; height: 36px; padding: 0 12px;
  border: 1px solid var(--border); border-radius: 8px;
  font-size: 14px; background: var(--bg); outline: none;
}
#searchInput:focus { border-color: var(--accent); background: var(--card); }
.search-results {
  position: absolute; top: 42px; left: 0; right: 0;
  background: var(--card); border: 1px solid var(--border); border-radius: var(--radius);
  box-shadow: 0 8px 24px rgba(0,0,0,.12); max-height: 60vh; overflow-y: auto;
}
.search-item { display: block; padding: 10px 14px; border-bottom: 1px solid var(--border); color: var(--text); }
.search-item:last-child { border-bottom: none; }
.search-item:hover { background: var(--accent-soft); text-decoration: none; }
.search-item .si-title { font-weight: 600; font-size: 14px; }
.search-item .si-meta { font-size: 12px; color: var(--muted); }
.search-item .si-snippet { font-size: 12px; color: var(--muted); display: block; overflow: hidden; text-overflow: ellipsis; white-space: nowrap; }
.search-empty { padding: 12px 14px; color: var(--muted); font-size: 13px; }

/* ===== 布局 ===== */
.layout { display: flex; max-width: 1200px; margin: 0 auto; }
.sidebar {
  width: 230px; flex-shrink: 0; padding: 20px 12px;
  position: sticky; top: 56px; height: calc(100vh - 56px); overflow-y: auto;
}
.nav-group { margin-bottom: 6px; }
.nav-item {
  display: block; padding: 7px 12px; border-radius: 8px;
  color: var(--text); font-size: 14px; font-weight: 600;
}
.nav-item:hover { background: var(--accent-soft); text-decoration: none; }
.nav-item.active { background: var(--accent-soft); color: var(--accent); }
.nav-sub { list-style: none; margin: 2px 0 8px; }
.nav-sub a {
  display: block; padding: 5px 12px 5px 26px; border-radius: 8px;
  color: var(--muted); font-size: 13px;
}
.nav-sub a:hover { background: var(--accent-soft); text-decoration: none; color: var(--accent); }
.nav-sub a.active { color: var(--accent); background: var(--accent-soft); }
.main { flex: 1; min-width: 0; padding: 24px 28px 60px; }
.overlay { position: fixed; inset: 56px 0 0 0; background: rgba(0,0,0,.35); z-index: 39; }

/* ===== 通用组件 ===== */
.hero { margin-bottom: 20px; }
.hero h1 { font-size: 26px; margin-bottom: 6px; }
.hero .sub { color: var(--muted); }
.hero .meta { font-size: 12px; color: var(--muted); margin-top: 6px; }
h2.page-title { font-size: 22px; margin-bottom: 6px; }
.page-desc { color: var(--muted); margin-bottom: 18px; }
h3.sec { font-size: 17px; margin: 26px 0 12px; }
.card {
  background: var(--card); border: 1px solid var(--border);
  border-radius: var(--radius); padding: 18px 20px; margin-bottom: 14px;
}
.grid { display: grid; grid-template-columns: repeat(auto-fill, minmax(250px, 1fr)); gap: 14px; }
.grid .card { margin-bottom: 0; }
.card h4 { font-size: 15px; margin-bottom: 6px; }
.card .desc { font-size: 13px; color: var(--muted); }
.card ul { padding-left: 20px; font-size: 13.5px; }
.card ul li { margin: 3px 0; }
.link-card { display: block; color: var(--text); transition: border-color .15s; }
.link-card:hover { border-color: var(--accent); text-decoration: none; }
.link-card h4 { color: var(--accent); }
.badge {
  display: inline-block; padding: 1px 9px; border-radius: 999px;
  font-size: 12px; font-weight: 600; margin-right: 6px; vertical-align: 2px;
}
.badge.student { background: #ecfdf5; color: #059669; }
.badge.work { background: var(--accent-soft); color: var(--accent); }
.badge.free { background: #ecfdf5; color: #059669; }
.badge.paid { background: #fef3c7; color: #b45309; }
.badge.soon { background: var(--code-bg); color: var(--muted); }
.notice {
  background: var(--warn-bg); border: 1px solid var(--warn-border);
  border-radius: var(--radius); padding: 12px 16px; margin-bottom: 16px; font-size: 13.5px;
}
.notice strong { color: #92400e; }
.tip {
  background: var(--accent-soft); border-left: 3px solid var(--accent);
  border-radius: 6px; padding: 10px 14px; margin: 12px 0; font-size: 13.5px;
}
.crumb { font-size: 13px; color: var(--muted); margin-bottom: 12px; }
.crumb a { color: var(--muted); }
.crumb a:hover { color: var(--accent); }

/* ===== 提示词块 ===== */
.prompt {
  position: relative; background: var(--code-bg); border: 1px solid var(--border);
  border-radius: var(--radius); padding: 14px 16px; margin: 10px 0;
}
.prompt pre {
  white-space: pre-wrap; word-break: break-word;
  font-family: inherit; font-size: 13.5px; line-height: 1.7;
}
.copy-btn {
  position: absolute; top: 8px; right: 8px;
  border: 1px solid var(--border); background: var(--card); color: var(--muted);
  border-radius: 6px; padding: 3px 10px; font-size: 12px; cursor: pointer;
}
.copy-btn:hover { color: var(--accent); border-color: var(--accent); }
.copy-btn.copied { color: #059669; border-color: #059669; }

/* ===== 表格 ===== */
.table-wrap { overflow-x: auto; margin: 10px 0; }
table { border-collapse: collapse; width: 100%; font-size: 13.5px; background: var(--card); }
th, td { border: 1px solid var(--border); padding: 8px 12px; text-align: left; vertical-align: top; }
th { background: var(--code-bg); font-weight: 600; white-space: nowrap; }

/* ===== 场景详情 ===== */
.meta-grid { display: grid; grid-template-columns: repeat(auto-fit, minmax(200px, 1fr)); gap: 10px; margin: 14px 0; }
.meta-item { background: var(--card); border: 1px solid var(--border); border-radius: 8px; padding: 10px 14px; font-size: 13px; }
.meta-item .k { color: var(--muted); font-size: 12px; display: block; }
.step-card { background: var(--card); border: 1px solid var(--border); border-radius: var(--radius); padding: 14px 18px; margin-bottom: 12px; }
.step-card .step-title { font-weight: 700; margin-bottom: 6px; }
.step-card .step-title .no {
  display: inline-block; width: 22px; height: 22px; line-height: 22px; text-align: center;
  background: var(--accent); color: #fff; border-radius: 50%; font-size: 12px; margin-right: 8px;
}
.soon-card { opacity: .65; }
.track-tabs { display: flex; gap: 8px; margin-bottom: 16px; flex-wrap: wrap; }
.track-tabs a {
  padding: 5px 16px; border-radius: 999px; border: 1px solid var(--border);
  background: var(--card); color: var(--muted); font-size: 13px;
}
.track-tabs a.active { background: var(--accent); border-color: var(--accent); color: #fff; }
.track-tabs a:hover { text-decoration: none; }
.article-body p { margin: 10px 0; }
.article-body ul { padding-left: 22px; margin: 10px 0; }
.article-body li { margin: 5px 0; }
.pager { display: flex; justify-content: space-between; gap: 10px; margin-top: 30px; font-size: 13.5px; }
.footer { text-align: center; color: var(--muted); font-size: 12px; padding: 20px 16px 30px; }
.back-top { display: inline-block; margin-top: 24px; font-size: 13px; }

/* ===== 移动端 ===== */
@media (max-width: 860px) {
  .menu-btn { display: block; }
  .sidebar {
    position: fixed; top: 56px; left: 0; bottom: 0; z-index: 40;
    background: var(--card); border-right: 1px solid var(--border);
    transform: translateX(-100%); transition: transform .2s ease;
    width: 250px; height: auto;
  }
  .sidebar.open { transform: translateX(0); }
  .main { padding: 18px 16px 50px; }
  .hero h1 { font-size: 22px; }
  .brand { font-size: 15px; }
  .grid { grid-template-columns: 1fr; }
  .pager { flex-direction: column; }
}
/* ===== 在线反馈表单 ===== */
.fb-form { display: grid; gap: 12px; }
.fb-form label { display: grid; gap: 6px; font-size: 14px; color: var(--muted); }
.fb-form select, .fb-form textarea, .fb-form input {
  font: inherit; padding: 8px 10px; border: 1px solid var(--border);
  border-radius: 8px; background: var(--bg); color: var(--text); width: 100%;
}
.fb-form textarea { resize: vertical; min-height: 96px; }
.fb-submit {
  justify-self: start; padding: 8px 20px; border: 0; border-radius: 8px;
  background: var(--accent); color: #fff; cursor: pointer; font-size: 14px;
}
.fb-submit:disabled { opacity: .6; cursor: default; }
.fb-msg { font-size: 14px; padding: 8px 12px; border-radius: 8px; }
.fb-msg.ok { background: #ecfdf5; color: #047857; }
.fb-msg.err { background: #fef2f2; color: #b91c1c; }