/* ============================================================
   Shadow AI · BP Website Styles
   Design: Apple Investor + Notion + Linear · 克制 / 留白 / 精致
   ============================================================ */

:root {
  --color-bg: #ffffff;
  --color-fg: #1a1a1a;
  --color-fg-muted: #6e6e73;
  --color-fg-light: #86868b;
  --color-border: #e5e5ea;
  --color-border-light: #f0f0f2;
  --color-accent: #0f1828;
  --color-accent-soft: #f4f6fa;
  --color-blue: #2c5dc8;
  --color-blue-dark: #1a3d8f;
  --color-risk-h: #c0392b;
  --color-risk-m: #d97706;
  --color-risk-l: #6e6e73;
  --font-zh: "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei", "Source Han Sans", sans-serif;
  --font-en: -apple-system, BlinkMacSystemFont, "SF Pro Display", "Helvetica Neue", sans-serif;
  --font-mono: "SF Mono", "JetBrains Mono", "Menlo", monospace;
  --max-w: 880px;
  --toc-w: 240px;
}

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

html { scroll-behavior: smooth; }

body {
  font-family: var(--font-zh);
  font-size: 16px;
  line-height: 1.75;
  color: var(--color-fg);
  background: var(--color-bg);
  font-feature-settings: "kern", "liga", "calt";
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
  text-rendering: optimizeLegibility;
}

/* ============================================================
   顶部导航 + 进度条
   ============================================================ */
.nav {
  position: fixed;
  top: 0; left: 0; right: 0;
  background: rgba(255,255,255,0.85);
  backdrop-filter: saturate(180%) blur(20px);
  -webkit-backdrop-filter: saturate(180%) blur(20px);
  border-bottom: 1px solid var(--color-border-light);
  z-index: 100;
}
.nav-inner {
  max-width: 1200px;
  margin: 0 auto;
  padding: 14px 32px;
  display: flex;
  align-items: center;
  justify-content: space-between;
}
.brand {
  display: flex;
  align-items: center;
  gap: 10px;
  font-size: 15px;
  font-weight: 500;
  letter-spacing: 0.5px;
}
.brand-mark {
  color: var(--color-accent);
  font-size: 10px;
  transform: translateY(-1px);
}
.brand-name { letter-spacing: 1px; }
.nav-meta {
  font-family: var(--font-en);
  font-size: 12px;
  color: var(--color-fg-muted);
  display: flex;
  gap: 10px;
  align-items: center;
}
.meta-divider { color: var(--color-border); }
.meta-confidential { color: var(--color-blue); font-weight: 500; }
.progress-bar {
  position: absolute;
  bottom: -1px;
  left: 0; right: 0;
  height: 2px;
  background: transparent;
}
.progress-fill {
  height: 100%;
  width: 0;
  background: linear-gradient(to right, var(--color-blue), var(--color-accent));
  transition: width 0.1s;
}

/* ============================================================
   左侧 TOC
   ============================================================ */
.toc {
  position: fixed;
  top: 100px;
  left: 32px;
  width: var(--toc-w);
  font-size: 13px;
  z-index: 50;
}
.toc-title {
  font-family: var(--font-en);
  font-size: 11px;
  letter-spacing: 3px;
  color: var(--color-fg-light);
  margin-bottom: 14px;
  font-weight: 500;
}
.toc nav { display: flex; flex-direction: column; gap: 2px; }
.toc-link {
  display: block;
  padding: 6px 12px;
  color: var(--color-fg-muted);
  text-decoration: none;
  border-left: 2px solid transparent;
  transition: all 0.2s;
  line-height: 1.4;
}
.toc-link:hover {
  color: var(--color-fg);
  border-left-color: var(--color-border);
}
.toc-link.active {
  color: var(--color-accent);
  border-left-color: var(--color-accent);
  font-weight: 500;
}

@media (max-width: 1280px) {
  .toc { display: none; }
}

/* ============================================================
   主内容容器
   ============================================================ */
.content {
  max-width: var(--max-w);
  margin: 0 auto;
  padding: 0 32px;
  padding-top: 60px;
}

/* ============================================================
   HERO 封面
   ============================================================ */
.hero {
  min-height: calc(100vh - 60px);
  display: flex;
  flex-direction: column;
  justify-content: center;
  padding: 80px 0 80px;
  border-bottom: 1px solid var(--color-border-light);
}
.hero-eyebrow {
  font-family: var(--font-en);
  font-size: 13px;
  letter-spacing: 6px;
  color: var(--color-blue);
  margin-bottom: 32px;
  font-weight: 500;
}
.hero-title {
  font-family: var(--font-en);
  font-size: 88px;
  font-weight: 300;
  letter-spacing: -2px;
  line-height: 1;
  color: var(--color-accent);
  margin-bottom: 24px;
}
.hero-sub {
  font-size: 28px;
  font-weight: 400;
  color: var(--color-accent);
  margin-bottom: 8px;
  letter-spacing: 1px;
}
.hero-sub-en {
  font-family: var(--font-en);
  font-size: 16px;
  font-weight: 300;
  color: var(--color-fg-muted);
  letter-spacing: 2px;
  font-style: italic;
  margin-bottom: 48px;
}
.hero-statement {
  font-size: 18px;
  line-height: 1.85;
  color: var(--color-fg);
  max-width: 640px;
  padding: 28px 32px;
  background: var(--color-accent-soft);
  border-left: 3px solid var(--color-blue);
  margin-bottom: 56px;
  border-radius: 2px;
}
.hero-stats {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 24px;
  margin-bottom: 48px;
}
.stat {
  border-top: 1px solid var(--color-border);
  padding-top: 20px;
}
.stat-value {
  font-family: var(--font-en);
  font-size: 36px;
  font-weight: 300;
  color: var(--color-accent);
  line-height: 1.1;
  letter-spacing: -1px;
}
.stat-unit {
  font-size: 14px;
  font-weight: 400;
  color: var(--color-fg-muted);
  margin-left: 4px;
  letter-spacing: 0;
}
.stat-label {
  font-size: 13px;
  color: var(--color-fg-muted);
  margin-top: 6px;
  letter-spacing: 0.5px;
}
.hero-scroll {
  font-family: var(--font-en);
  font-size: 12px;
  letter-spacing: 3px;
  color: var(--color-fg-light);
  text-align: center;
  margin-top: 40px;
}

@media (max-width: 720px) {
  .hero-title { font-size: 56px; }
  .hero-sub { font-size: 22px; }
  .hero-stats { grid-template-columns: repeat(2, 1fr); }
}

/* ============================================================
   章节
   ============================================================ */
.chapter {
  padding: 96px 0;
  border-bottom: 1px solid var(--color-border-light);
}
.chapter:last-of-type { border-bottom: none; }

.chapter-num {
  font-family: var(--font-en);
  font-size: 12px;
  letter-spacing: 4px;
  color: var(--color-blue);
  margin-bottom: 16px;
  font-weight: 500;
}
.chapter-title {
  font-size: 40px;
  font-weight: 400;
  color: var(--color-accent);
  letter-spacing: 1px;
  margin-bottom: 48px;
  line-height: 1.2;
}

.section-title {
  font-size: 18px;
  font-weight: 600;
  color: var(--color-accent);
  margin: 44px 0 16px;
  padding-left: 12px;
  border-left: 3px solid var(--color-blue);
  letter-spacing: 0.5px;
}

.lead {
  font-size: 18px;
  line-height: 1.85;
  color: var(--color-fg);
  margin-bottom: 24px;
}
.lead-strong {
  font-size: 20px;
  padding: 20px 24px;
  background: var(--color-accent-soft);
  border-radius: 8px;
  border-left: 3px solid var(--color-blue);
}

.callout {
  background: var(--color-accent-soft);
  border-left: 3px solid var(--color-blue);
  padding: 18px 24px;
  margin: 24px 0;
  font-size: 15px;
  line-height: 1.75;
  border-radius: 2px;
}

p {
  margin-bottom: 14px;
  color: var(--color-fg);
}

.conclusion {
  font-size: 16px;
  margin-top: 18px;
  color: var(--color-accent);
}

ul, ol {
  margin: 0 0 16px 0;
  padding-left: 24px;
}
li {
  margin-bottom: 6px;
  line-height: 1.7;
}

strong { font-weight: 600; color: var(--color-accent); }

/* ============================================================
   表格
   ============================================================ */
table {
  width: 100%;
  border-collapse: collapse;
  margin: 16px 0 24px;
  font-size: 14.5px;
  border: 1px solid var(--color-border);
  border-radius: 6px;
  overflow: hidden;
}
thead {
  background: var(--color-accent);
  color: #fff;
}
th {
  text-align: left;
  padding: 12px 16px;
  font-weight: 500;
  letter-spacing: 0.5px;
  font-size: 13.5px;
}
td {
  padding: 12px 16px;
  border-top: 1px solid var(--color-border-light);
  vertical-align: top;
  line-height: 1.6;
}
tbody tr:nth-child(even) { background: #fafbfc; }
tbody tr:hover { background: #f4f6fa; }

.kv-table thead { display: none; }
.kv-table td:first-child {
  width: 35%;
  font-weight: 500;
  color: var(--color-accent);
}

/* ============================================================
   三层飞轮（特别布局）
   ============================================================ */
.flywheel {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 16px;
  margin: 24px 0 32px;
}
.flywheel-col {
  border: 1px solid var(--color-border);
  border-radius: 8px;
  padding: 20px 22px;
  background: #fafbfc;
  transition: all 0.2s;
}
.flywheel-col:hover {
  border-color: var(--color-blue);
  background: var(--color-accent-soft);
}
.flywheel-highlight {
  background: var(--color-accent-soft);
  border-color: var(--color-blue);
}
.flywheel-tag {
  font-family: var(--font-en);
  font-size: 11px;
  letter-spacing: 2px;
  color: var(--color-blue);
  margin-bottom: 8px;
  font-weight: 500;
}
.flywheel-name {
  font-size: 19px;
  font-weight: 600;
  color: var(--color-accent);
  margin-bottom: 12px;
  letter-spacing: 0.5px;
}
.flywheel-desc {
  font-size: 13.5px;
  line-height: 1.7;
  color: var(--color-fg);
}

@media (max-width: 720px) {
  .flywheel { grid-template-columns: 1fr; }
}

/* ============================================================
   两列卡片
   ============================================================ */
.two-col {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 16px;
  margin: 16px 0 24px;
}
.col-card {
  border: 1px solid var(--color-border);
  border-radius: 8px;
  padding: 20px 22px;
  background: #fafbfc;
}
.col-title {
  font-weight: 600;
  font-size: 15px;
  color: var(--color-accent);
  margin-bottom: 12px;
}
.col-card ul { padding-left: 20px; }
.col-card li { font-size: 14px; margin-bottom: 4px; }

@media (max-width: 720px) {
  .two-col { grid-template-columns: 1fr; }
}

/* ============================================================
   边界 / 不做什么列表
   ============================================================ */
.boundary-box {
  margin-top: 32px;
  padding: 20px 24px;
  border: 1px dashed var(--color-border);
  border-radius: 6px;
  background: #fafbfc;
}
.boundary-title {
  font-size: 13px;
  letter-spacing: 2px;
  color: var(--color-fg-muted);
  margin-bottom: 12px;
  font-weight: 500;
}
.boundary-list {
  list-style: none;
  padding-left: 0;
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: 4px 24px;
}
.boundary-list li {
  font-size: 14px;
  color: var(--color-fg);
  padding-left: 20px;
  position: relative;
}
.boundary-list li::before {
  content: "✕";
  position: absolute;
  left: 0;
  color: var(--color-risk-h);
  font-size: 12px;
}
.dont-list { list-style: none; padding-left: 0; }
.dont-list li {
  padding: 4px 0;
  font-size: 15px;
}
.dont-x {
  display: inline-block;
  width: 22px;
  color: var(--color-risk-h);
  font-weight: 600;
}

/* ============================================================
   飞轮步骤
   ============================================================ */
.flywheel-steps {
  list-style: none;
  padding-left: 0;
  margin: 24px 0;
  counter-reset: step;
}
.flywheel-steps li {
  display: flex;
  align-items: center;
  gap: 16px;
  padding: 14px 20px;
  background: #fafbfc;
  border-left: 3px solid var(--color-blue);
  border-radius: 0 6px 6px 0;
  margin-bottom: 8px;
  font-size: 15px;
}
.step-num {
  flex-shrink: 0;
  width: 32px;
  height: 32px;
  border-radius: 50%;
  background: var(--color-accent);
  color: #fff;
  display: inline-flex;
  align-items: center;
  justify-content: center;
  font-family: var(--font-en);
  font-size: 13px;
  font-weight: 500;
}
.step-text { line-height: 1.6; }

/* ============================================================
   护城河（核心竞争力）
   ============================================================ */
.moat {
  border: 1px solid var(--color-border);
  border-radius: 8px;
  padding: 24px 28px;
  margin-bottom: 16px;
  background: #fafbfc;
}
.moat-rank {
  font-family: var(--font-en);
  font-size: 14px;
  color: var(--color-blue);
  letter-spacing: 2px;
  margin-bottom: 6px;
  font-weight: 500;
}
.moat-rank-tag {
  background: var(--color-blue);
  color: #fff;
  font-size: 10px;
  letter-spacing: 1px;
  padding: 2px 8px;
  border-radius: 3px;
  margin-left: 8px;
}
.moat-name {
  font-size: 19px;
  font-weight: 600;
  color: var(--color-accent);
  margin-bottom: 14px;
  letter-spacing: 0.5px;
}
.moat-body ul { padding-left: 20px; }
.moat-body li { font-size: 14.5px; margin-bottom: 5px; }
.moat-body p { font-size: 14.5px; margin-top: 10px; }
.moat-body table { margin: 12px 0; font-size: 13.5px; }

/* ============================================================
   架构图
   ============================================================ */
.arch {
  margin: 16px 0 28px;
  background: var(--color-accent);
  color: #fff;
  border-radius: 8px;
  padding: 24px;
}
.arch-layer {
  display: grid;
  grid-template-columns: 60px 100px 1fr;
  align-items: center;
  padding: 12px 16px;
  background: rgba(255,255,255,0.06);
  border-radius: 4px;
  margin-bottom: 6px;
  gap: 12px;
}
.arch-tag {
  font-family: var(--font-en);
  font-size: 11px;
  letter-spacing: 1px;
  color: #8fa8d4;
  font-weight: 500;
}
.arch-name {
  font-size: 14px;
  font-weight: 500;
  color: #fff;
}
.arch-detail {
  font-size: 13px;
  color: #b4c4dc;
}
.arch-external {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 8px;
  margin-top: 16px;
}
.arch-ext-box {
  padding: 10px 16px;
  background: rgba(255,255,255,0.04);
  border: 1px dashed rgba(255,255,255,0.2);
  border-radius: 4px;
  font-size: 13px;
  text-align: center;
  color: #b4c4dc;
}

/* ============================================================
   端到端流程
   ============================================================ */
.flow {
  background: var(--color-accent);
  color: #fff;
  border-radius: 8px;
  padding: 24px 20px;
  margin: 16px 0 20px;
}
.flow-row {
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 8px;
  flex-wrap: wrap;
}
.flow-row + .flow-side + .flow-row { margin-top: 12px; }
.flow-step {
  background: rgba(255,255,255,0.08);
  border: 1px solid rgba(255,255,255,0.1);
  padding: 8px 14px;
  border-radius: 4px;
  font-size: 13px;
  display: flex;
  align-items: center;
  gap: 6px;
}
.flow-ext { background: rgba(95, 130, 200, 0.25); border-color: rgba(95, 130, 200, 0.5); }
.flow-n { color: #8fa8d4; font-family: var(--font-en); font-size: 12px; }
.flow-arrow { color: #6a82a8; font-size: 18px; }
.flow-side {
  text-align: center;
  font-size: 12px;
  color: #8fa8d4;
  margin: 12px 0;
  font-style: italic;
}

/* ============================================================
   团队 grid
   ============================================================ */
.team-grid {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: 0;
  border: 1px solid var(--color-border);
  border-radius: 6px;
  overflow: hidden;
  margin: 16px 0 24px;
}
.team-cell {
  display: flex;
  justify-content: space-between;
  align-items: center;
  padding: 10px 16px;
  font-size: 14px;
  border-top: 1px solid var(--color-border-light);
  border-left: 1px solid var(--color-border-light);
}
.team-cell:nth-child(-n+2) { border-top: none; }
.team-cell:nth-child(2n+1) { border-left: none; }
.team-cell span:last-child {
  font-family: var(--font-en);
  color: var(--color-fg-muted);
  font-weight: 500;
}
.team-total {
  background: var(--color-accent-soft);
}
.team-total span:last-child { color: var(--color-accent); }

/* ============================================================
   value list / action list
   ============================================================ */
.value-list, .action-list {
  list-style: none;
  padding-left: 0;
  counter-reset: vl;
}
.value-list li, .action-list li {
  position: relative;
  padding: 10px 0 10px 36px;
  font-size: 15px;
  border-bottom: 1px solid var(--color-border-light);
}
.value-list li:last-child, .action-list li:last-child { border-bottom: none; }
.value-list li::before, .action-list li::before {
  counter-increment: vl;
  content: counter(vl);
  position: absolute;
  left: 0;
  top: 11px;
  width: 24px;
  height: 24px;
  border-radius: 50%;
  background: var(--color-accent);
  color: #fff;
  display: flex;
  align-items: center;
  justify-content: center;
  font-family: var(--font-en);
  font-size: 12px;
  font-weight: 500;
}

/* ============================================================
   风险等级标签
   ============================================================ */
.risk-h, .risk-m, .risk-l {
  display: inline-block;
  padding: 2px 8px;
  font-size: 12px;
  font-weight: 500;
  border-radius: 3px;
  letter-spacing: 0.5px;
}
.risk-h { background: rgba(192,57,43,0.1); color: var(--color-risk-h); }
.risk-m { background: rgba(217,119,6,0.1); color: var(--color-risk-m); }
.risk-l { background: rgba(110,110,115,0.1); color: var(--color-risk-l); }

.redlines {
  padding: 16px 20px;
  background: rgba(192,57,43,0.04);
  border-left: 3px solid var(--color-risk-h);
  border-radius: 4px;
  font-size: 14.5px;
}

/* ============================================================
   Footer
   ============================================================ */
.footer {
  border-top: 1px solid var(--color-border);
  padding: 48px 0 64px;
  margin-top: 40px;
}
.footer-inner {
  text-align: center;
}
.footer-brand {
  font-family: var(--font-en);
  font-size: 14px;
  letter-spacing: 4px;
  color: var(--color-accent);
  margin-bottom: 12px;
  font-weight: 500;
}
.footer-meta {
  font-size: 13px;
  color: var(--color-fg-muted);
  line-height: 1.8;
}

/* ============================================================
   响应式
   ============================================================ */
@media (max-width: 720px) {
  .nav-inner { padding: 12px 20px; }
  .nav-meta { font-size: 10px; gap: 6px; }
  .content { padding: 60px 20px 0; }
  .chapter { padding: 60px 0; }
  .chapter-title { font-size: 28px; margin-bottom: 32px; }
  .hero-title { font-size: 56px; }
  .hero { padding: 40px 0; }
  .boundary-list { grid-template-columns: 1fr; }
  table { font-size: 13px; }
  th, td { padding: 10px 12px; }
  .team-grid { grid-template-columns: 1fr; }
  .team-cell { border-left: none !important; }
  .team-cell:first-child { border-top: none !important; }
}