/* 1:1 搬迁自原 HTML 第 7–296 行。所有变量与 48 个类完整保留。 */

:root {
  --color-bg: #ffffff;
  --color-bg-soft: #f7f9fc;
  --color-bg-card: #ffffff;
  --color-text: #1f2328;
  --color-text-soft: #57606a;
  --color-text-muted: #8c959f;
  --color-primary: #1a73e8;
  --color-primary-soft: #e8f0fe;
  --color-primary-dark: #1557b0;
  --color-accent: #f59e0b;
  --color-border: #e4e7eb;
  --color-border-strong: #d1d5da;
  --color-table-head: #1a73e8;
  --color-table-alt: #f7f9fc;
  --color-quote-bar: #1a73e8;
  --color-shadow: rgba(15, 23, 42, 0.06);
  --nav-width: 280px;
  --content-max: 920px;
}

[data-theme="dark"] {
  --color-bg: #0d1117;
  --color-bg-soft: #161b22;
  --color-bg-card: #161b22;
  --color-text: #e6edf3;
  --color-text-soft: #b1bac4;
  --color-text-muted: #768390;
  --color-primary: #58a6ff;
  --color-primary-soft: #1f6feb33;
  --color-primary-dark: #79c0ff;
  --color-border: #30363d;
  --color-border-strong: #444c56;
  --color-table-head: #1f6feb;
  --color-table-alt: #1c2128;
  --color-shadow: rgba(0, 0, 0, 0.4);
}

* { box-sizing: border-box; }
html { scroll-behavior: smooth; scroll-padding-top: 80px; }

body {
  margin: 0;
  font-family: -apple-system, BlinkMacSystemFont, "PingFang SC", "Hiragino Sans GB",
               "Microsoft YaHei", "Helvetica Neue", Arial, sans-serif;
  font-size: 15px;
  line-height: 1.75;
  color: var(--color-text);
  background: var(--color-bg);
  transition: background 0.3s, color 0.3s;
}

/* 顶部条 */
.topbar {
  position: fixed; top: 0; left: 0; right: 0; z-index: 100;
  background: var(--color-bg);
  border-bottom: 1px solid var(--color-border);
  backdrop-filter: blur(10px);
  background: color-mix(in srgb, var(--color-bg) 92%, transparent);
}
.topbar-inner {
  display: flex; align-items: center; justify-content: space-between;
  height: 56px; padding: 0 28px; max-width: 1600px; margin: 0 auto;
}
.topbar-left { font-weight: 600; font-size: 14px; color: var(--color-text); }
.topbar-right { display: flex; gap: 8px; }
.theme-toggle, .back-to-top {
  border: 1px solid var(--color-border); background: var(--color-bg-soft);
  width: 36px; height: 36px; border-radius: 8px; cursor: pointer;
  font-size: 16px; transition: all 0.2s; color: var(--color-text);
}
.theme-toggle:hover, .back-to-top:hover {
  background: var(--color-primary-soft); border-color: var(--color-primary); color: var(--color-primary);
}
.progress-bar { height: 2px; background: var(--color-bg-soft); }
.progress-fill { height: 100%; background: linear-gradient(90deg, var(--color-primary), var(--color-accent)); width: 0; transition: width 0.1s; }

/* 侧边栏 */
.side-nav {
  position: fixed; top: 58px; left: 0; bottom: 0; width: var(--nav-width);
  background: var(--color-bg-soft); border-right: 1px solid var(--color-border);
  overflow-y: auto; z-index: 50;
  transition: transform 0.3s;
}
.nav-inner { padding: 24px 16px 80px; }
.nav-brand {
  padding: 12px 16px 18px; border-bottom: 1px solid var(--color-border); margin-bottom: 16px;
}
.brand-line { width: 32px; height: 3px; background: var(--color-primary); border-radius: 2px; margin-bottom: 10px; }
.brand-text { font-weight: 700; font-size: 14px; color: var(--color-text); line-height: 1.5; }
.nav-list { list-style: none; padding: 0; margin: 0; }
.nav-list li { margin: 0; }
.nav-list a {
  display: block; padding: 7px 14px; color: var(--color-text-soft);
  text-decoration: none; border-left: 2px solid transparent;
  font-size: 13px; line-height: 1.5; transition: all 0.15s;
  border-radius: 0 6px 6px 0;
}
.nav-h2 a {
  font-weight: 600; color: var(--color-text); padding-left: 14px; margin-top: 12px;
  font-size: 13.5px;
}
.nav-h2:first-child a { margin-top: 0; }
.nav-h3 a { font-size: 12.5px; padding-left: 28px; color: var(--color-text-soft); }
.nav-list a:hover {
  background: var(--color-primary-soft); color: var(--color-primary); border-left-color: var(--color-primary);
}
.nav-footer {
  margin-top: 24px; padding: 12px 16px; border-top: 1px solid var(--color-border);
  font-size: 11px; color: var(--color-text-muted); line-height: 1.6;
}

/* 主内容 */
main {
  margin-left: var(--nav-width);
  padding: 78px 32px 60px;
  min-height: 100vh;
}
.content {
  max-width: var(--content-max); margin: 0 auto;
}

/* 封面 */
.cover {
  min-height: calc(100vh - 80px);
  display: flex; align-items: center; justify-content: center;
  position: relative; overflow: hidden;
  margin-bottom: 40px;
  border-radius: 20px;
  background: linear-gradient(135deg, #1a73e8 0%, #4285f4 50%, #34a853 100%);
  color: white;
}
[data-theme="dark"] .cover {
  background: linear-gradient(135deg, #0d47a1 0%, #1a237e 50%, #004d40 100%);
}
.cover-deco {
  position: absolute; inset: 0;
  background:
    radial-gradient(circle at 20% 30%, rgba(255,255,255,0.15), transparent 50%),
    radial-gradient(circle at 80% 70%, rgba(255,255,255,0.1), transparent 50%);
}
.cover-inner { position: relative; text-align: center; padding: 80px 40px; max-width: 760px; }
.cover-tag {
  display: inline-block; padding: 6px 16px; border-radius: 999px;
  background: rgba(255,255,255,0.2); backdrop-filter: blur(8px);
  font-size: 13px; letter-spacing: 2px; margin-bottom: 28px;
}
.cover-title {
  font-size: 56px; font-weight: 800; line-height: 1.2; margin: 0 0 16px;
  letter-spacing: -1px;
}
.cover-sub {
  font-size: 18px; font-weight: 300; opacity: 0.9; margin-bottom: 48px;
}
.cover-meta {
  display: flex; flex-direction: column; gap: 12px;
  background: rgba(255,255,255,0.12); padding: 20px 28px; border-radius: 12px;
  backdrop-filter: blur(8px); margin-bottom: 36px;
  text-align: left;
}
.meta-item { display: flex; gap: 12px; font-size: 13.5px; align-items: baseline; }
.meta-label {
  flex-shrink: 0; width: 72px; opacity: 0.7; font-size: 12px;
  text-transform: uppercase; letter-spacing: 1px;
}
.meta-value { font-weight: 500; }
.cover-toc-hint {
  font-size: 12px; opacity: 0.7; letter-spacing: 0.5px;
}

/* 章节 */
.chapter {
  margin: 60px 0 40px;
  padding-top: 20px;
}
.chapter-num {
  font-size: 13px; font-weight: 600; color: var(--color-primary);
  letter-spacing: 3px; text-transform: uppercase; margin-bottom: 8px;
}
.chapter-title {
  font-size: 32px; font-weight: 700; margin: 0 0 16px;
  color: var(--color-text); letter-spacing: -0.5px;
  border-bottom: 3px solid var(--color-primary);
  padding-bottom: 12px; display: inline-block;
}
.sub-section { margin: 36px 0 20px; scroll-margin-top: 80px; }
.sub-title {
  font-size: 20px; font-weight: 700; margin: 0 0 14px;
  color: var(--color-text); position: relative; padding-left: 14px;
}
.sub-title::before {
  content: ''; position: absolute; left: 0; top: 6px; bottom: 6px;
  width: 4px; background: var(--color-primary); border-radius: 2px;
}
.sub-sub-title {
  font-size: 15.5px; font-weight: 700; margin: 20px 0 10px;
  color: var(--color-primary); padding: 4px 0;
  border-bottom: 1px dashed var(--color-border-strong);
}

/* 段落 */
p {
  margin: 14px 0; color: var(--color-text);
  text-align: justify;
}
strong { color: var(--color-primary-dark); font-weight: 600; }
[data-theme="dark"] strong { color: var(--color-primary-dark); }
a { color: var(--color-primary); text-decoration: none; }
a:hover { text-decoration: underline; }
code {
  background: var(--color-bg-soft); padding: 2px 6px; border-radius: 4px;
  font-family: "SF Mono", Consolas, Menlo, monospace; font-size: 13px;
}

/* 引用 */
.quote {
  margin: 18px 0; padding: 12px 18px;
  border-left: 4px solid var(--color-quote-bar);
  background: var(--color-primary-soft);
  border-radius: 0 8px 8px 0;
  color: var(--color-text-soft);
  font-size: 14px;
}
.quote p { margin: 0; }

/* 列表 */
.report-list { margin: 14px 0; padding-left: 26px; }
.report-list li { margin: 6px 0; line-height: 1.75; }
.report-list li::marker { color: var(--color-primary); font-weight: 700; }
.report-list.ordered li::marker { color: var(--color-primary); }

/* 表格 */
.table-wrap {
  margin: 22px 0; overflow-x: auto;
  border-radius: 10px;
  box-shadow: 0 2px 8px var(--color-shadow);
  border: 1px solid var(--color-border);
}
.report-table {
  width: 100%; border-collapse: collapse; font-size: 13px;
  background: var(--color-bg-card);
}
.report-table th {
  background: var(--color-table-head); color: white;
  padding: 12px 14px; text-align: left; font-weight: 600;
  font-size: 13px; letter-spacing: 0.3px; white-space: nowrap;
  border-bottom: 2px solid var(--color-primary-dark);
}
.report-table td {
  padding: 11px 14px; border-bottom: 1px solid var(--color-border);
  vertical-align: top; line-height: 1.6;
}
.report-table tbody tr.alt { background: var(--color-table-alt); }
.report-table tbody tr:hover { background: var(--color-primary-soft); transition: background 0.15s; }
.report-table tbody tr:last-child td { border-bottom: none; }

/* 分隔线 */
.divider {
  border: none; height: 1px; background: var(--color-border);
  margin: 32px 0;
}

/* 页脚 */
.report-footer {
  margin: 80px 0 0; padding: 32px 0 24px;
  border-top: 1px solid var(--color-border);
  text-align: center; color: var(--color-text-muted);
  font-size: 12.5px; line-height: 1.8;
}
.footer-meta { margin-top: 8px; font-size: 11.5px; }

/* 响应式 */
@media (max-width: 1024px) {
  :root { --nav-width: 0px; }
  .side-nav { transform: translateX(-100%); }
  .side-nav.open { transform: translateX(0); box-shadow: 4px 0 20px var(--color-shadow); }
  main { margin-left: 0; padding: 70px 20px 40px; }
  .cover-title { font-size: 36px; }
  .chapter-title { font-size: 24px; }
}

@media print {
  .topbar, .side-nav, .back-to-top { display: none; }
  main { margin-left: 0; padding: 0; }
  .cover { min-height: auto; padding: 40px 0; page-break-after: always; }
  .chapter { page-break-before: always; }
  .report-table { page-break-inside: avoid; }
}