:root {
  --bg: #f6f8f5;
  --paper: #fffefa;
  --surface: #ffffff;
  --ink: #18211f;
  --muted: #66736f;
  --line: #dfe5df;
  --line-strong: #c9d2cb;
  --accent: #0d776f;
  --accent-soft: #dcefeb;
  --amber: #d98923;
  --amber-soft: #fff0d8;
  --code: #10201e;
  --shadow: 0 14px 38px rgba(34, 45, 41, 0.08);
  --radius: 6px;
  font-family: Inter, ui-sans-serif, system-ui, -apple-system, BlinkMacSystemFont, "PingFang SC", "Microsoft YaHei", "Noto Sans CJK SC", sans-serif;
  color: var(--ink);
  background: var(--bg);
}

* { box-sizing: border-box; }
html { scroll-behavior: smooth; }
body {
  margin: 0;
  min-height: 100vh;
  background:
    linear-gradient(rgba(255, 255, 255, 0.56), rgba(255, 255, 255, 0.18)),
    radial-gradient(circle at 20% 0%, rgba(13, 119, 111, 0.08), transparent 32%),
    var(--bg);
  color: var(--ink);
}

button, input { font: inherit; }
textarea { font: inherit; }
button { cursor: pointer; }
a { color: inherit; }

.app-shell {
  display: grid;
  grid-template-columns: 280px minmax(0, 1fr);
  min-height: 100vh;
}

.sidebar {
  position: sticky;
  top: 0;
  height: 100vh;
  padding: 22px 18px;
  border-right: 1px solid var(--line);
  background: rgba(255, 254, 250, 0.86);
  backdrop-filter: blur(18px);
  overflow-y: auto;
}

.brand {
  display: flex;
  gap: 12px;
  align-items: center;
  text-decoration: none;
  margin-bottom: 30px;
}

.brand-mark {
  display: grid;
  place-items: center;
  width: 42px;
  height: 42px;
  border: 1px solid var(--line-strong);
  background: var(--ink);
  color: #fffefa;
  border-radius: var(--radius);
  font-size: 12px;
  font-weight: 800;
  letter-spacing: 0;
}

.brand strong, .brand em { display: block; }
.brand strong { font-size: 16px; line-height: 1.2; }
.brand em { margin-top: 2px; color: var(--muted); font-size: 12px; font-style: normal; }

.side-nav { display: grid; gap: 6px; margin-bottom: 28px; }
.nav-item {
  display: flex;
  justify-content: space-between;
  align-items: center;
  gap: 12px;
  border: 1px solid transparent;
  background: transparent;
  color: var(--muted);
  border-radius: var(--radius);
  padding: 9px 10px;
  text-align: left;
  width: 100%;
  font-size: 14px;
}
.nav-item:hover, .nav-item.active { color: var(--ink); background: var(--accent-soft); border-color: #c5e0da; }
.nav-item span:last-child { font-size: 12px; color: var(--muted); }

.upload-panel,
.draft-panel {
  border-top: 1px solid var(--line);
  padding-top: 20px;
}
.draft-panel { margin-top: 20px; }
.upload-panel h2, .draft-panel h2, .toc-panel h2, .quick-card h2 {
  margin: 0 0 8px;
  font-size: 13px;
  text-transform: uppercase;
  letter-spacing: .08em;
}
.upload-panel p {
  margin: 0 0 14px;
  color: var(--muted);
  font-size: 13px;
  line-height: 1.55;
}
.upload-button {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  min-height: 36px;
  padding: 0 12px;
  border-radius: var(--radius);
  background: var(--ink);
  color: #fff;
  font-size: 13px;
}
.upload-button input { display: none; }
.upload-list { margin-top: 12px; display: grid; gap: 6px; color: var(--muted); font-size: 12px; }
.secondary-button {
  min-height: 36px;
  width: 100%;
  border: 1px solid var(--line-strong);
  border-radius: var(--radius);
  background: var(--surface);
  color: var(--ink);
  padding: 0 12px;
  font-size: 13px;
}
.secondary-button:hover { border-color: var(--accent); background: var(--accent-soft); }

.main { min-width: 0; padding: 24px 28px 54px; }
.topbar {
  display: flex;
  justify-content: space-between;
  gap: 24px;
  align-items: center;
  margin: 0 auto 24px;
  max-width: 1360px;
}
.topbar h1 { margin: 0; font-size: clamp(28px, 4vw, 48px); line-height: 1.02; letter-spacing: 0; }
.topbar p { margin: 8px 0 0; color: var(--muted); }

.search-wrap {
  display: flex;
  gap: 8px;
  align-items: center;
  min-width: min(460px, 40vw);
}
.search-wrap input {
  width: 100%;
  min-height: 44px;
  border: 1px solid var(--line-strong);
  border-radius: var(--radius);
  background: var(--surface);
  padding: 0 14px;
  color: var(--ink);
  outline: none;
  box-shadow: 0 1px 0 rgba(255,255,255,0.8);
}
.search-wrap input:focus { border-color: var(--accent); box-shadow: 0 0 0 3px rgba(13, 119, 111, .14); }
.search-wrap button, .view-actions button, .back-link, .article-actions button, .editor-toolbar button {
  min-height: 42px;
  border: 1px solid var(--line-strong);
  border-radius: var(--radius);
  background: var(--surface);
  color: var(--ink);
  padding: 0 12px;
  font-size: 13px;
}

.home-view, .article-view { max-width: 1360px; margin: 0 auto; }
.feature-row {
  display: grid;
  grid-template-columns: minmax(0, 1.7fr) minmax(280px, .8fr);
  gap: 16px;
  margin-bottom: 18px;
}
.hero-card, .quick-card {
  background: var(--paper);
  border: 1px solid var(--line);
  border-radius: var(--radius);
  box-shadow: var(--shadow);
}
.hero-card {
  min-height: 270px;
  display: grid;
  grid-template-columns: minmax(240px, .8fr) minmax(0, 1fr);
  overflow: hidden;
}
.hero-card img {
  width: 100%;
  height: 100%;
  object-fit: contain;
  padding: 24px;
  background: #f3f7f3;
  border-right: 1px solid var(--line);
}
.hero-card div { padding: 34px; align-self: end; }
.hero-card h2 { margin: 0 0 14px; font-size: clamp(30px, 4vw, 56px); line-height: 1.02; max-width: 760px; }
.hero-card p { margin: 0; color: var(--muted); font-size: 17px; line-height: 1.65; max-width: 740px; }
.quick-card { padding: 24px; }
.quick-card ol { margin: 16px 0 0; padding-left: 20px; color: var(--muted); line-height: 1.7; }

.toolbar {
  display: flex;
  justify-content: space-between;
  align-items: center;
  gap: 16px;
  margin: 22px 0 14px;
}
.chip-row { display: flex; gap: 8px; flex-wrap: wrap; }
.chip {
  min-height: 34px;
  border: 1px solid var(--line-strong);
  border-radius: 999px;
  background: var(--surface);
  color: var(--muted);
  padding: 0 12px;
  font-size: 13px;
}
.chip.active { color: var(--ink); background: var(--amber-soft); border-color: #efcf9a; }
.view-actions { display: flex; gap: 8px; }

.doc-grid {
  display: grid;
  grid-template-columns: repeat(3, minmax(0, 1fr));
  gap: 14px;
}
.doc-card {
  display: flex;
  flex-direction: column;
  gap: 14px;
  min-height: 250px;
  border: 1px solid var(--line);
  border-radius: var(--radius);
  background: var(--surface);
  padding: 18px;
  box-shadow: 0 8px 24px rgba(34, 45, 41, 0.04);
  text-decoration: none;
}
.doc-card:hover { border-color: #b5cbc5; transform: translateY(-1px); transition: transform .18s ease, border-color .18s ease; }
.doc-card header { display: flex; justify-content: space-between; gap: 10px; color: var(--muted); font-size: 12px; }
.doc-card h2 { margin: 0; font-size: 22px; line-height: 1.25; }
.doc-card p { margin: 0; color: var(--muted); line-height: 1.6; }
.doc-tags { margin-top: auto; display: flex; flex-wrap: wrap; gap: 6px; }
.doc-tags span { border: 1px solid var(--line); background: #fbfcfa; border-radius: 999px; padding: 4px 8px; color: var(--muted); font-size: 12px; }

.article-layout {
  display: grid;
  grid-template-columns: minmax(0, 840px) 300px;
  gap: 26px;
  align-items: start;
}
.back-link { margin-bottom: 14px; }
.article-body-wrap {
  background: var(--paper);
  border: 1px solid var(--line);
  border-radius: var(--radius);
  box-shadow: var(--shadow);
  padding: clamp(24px, 4vw, 52px);
}
.article-meta {
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
  color: var(--muted);
  font-size: 13px;
  margin-bottom: 14px;
}
.article-meta span { border: 1px solid var(--line); border-radius: 999px; padding: 5px 9px; background: #fbfcfa; }

.article-actions {
  display: flex;
  justify-content: space-between;
  align-items: center;
  gap: 12px;
  margin-bottom: 24px;
  padding-bottom: 18px;
  border-bottom: 1px solid var(--line);
}
.action-group { display: flex; align-items: center; gap: 8px; flex-wrap: wrap; }
.article-actions button:hover,
.editor-toolbar button:hover { border-color: var(--accent); background: var(--accent-soft); }
.draft-status {
  min-height: 20px;
  color: var(--muted);
  font-size: 13px;
  text-align: right;
}

.editor-panel {
  margin-bottom: 28px;
  border: 1px solid var(--line-strong);
  border-radius: var(--radius);
  background: #fbfcfa;
  overflow: hidden;
}
.editor-toolbar {
  display: flex;
  justify-content: space-between;
  align-items: center;
  gap: 12px;
  padding: 12px;
  border-bottom: 1px solid var(--line);
  background: #f1f6f3;
}
.editor-toolbar strong { font-size: 14px; }
.editor-grid {
  display: grid;
  grid-template-columns: minmax(0, 1fr) minmax(0, 1fr);
  min-height: 520px;
}
.editor-grid textarea {
  width: 100%;
  min-height: 520px;
  resize: vertical;
  border: 0;
  border-right: 1px solid var(--line);
  border-radius: 0;
  background: #fffefa;
  color: var(--ink);
  padding: 18px;
  outline: none;
  font-family: "SFMono-Regular", Consolas, "Liberation Mono", monospace;
  font-size: 14px;
  line-height: 1.62;
}
.editor-grid textarea:focus { box-shadow: inset 0 0 0 2px rgba(13, 119, 111, .18); }
.editor-preview {
  min-height: 520px;
  max-height: 70vh;
  overflow: auto;
  padding: 18px;
  background: var(--surface);
}
.editor-preview h1 { font-size: 34px; }
.editor-preview h2 { font-size: 24px; margin-top: 28px; }

.article-body { font-size: 16px; line-height: 1.78; }
.article-body h1 {
  font-size: clamp(34px, 5vw, 62px);
  line-height: 1.05;
  letter-spacing: 0;
  margin: 0 0 26px;
}
.article-body h2 { font-size: 28px; margin: 44px 0 14px; line-height: 1.2; }
.article-body h3 { font-size: 21px; margin: 34px 0 10px; }
.article-body h4 { font-size: 17px; margin: 28px 0 8px; }
.article-body p { margin: 14px 0; }
.article-body a { color: var(--accent); text-decoration-thickness: 1px; text-underline-offset: 3px; }
.article-body img { max-width: 100%; border-radius: var(--radius); border: 1px solid var(--line); display: block; margin: 18px 0; }
.article-body pre {
  overflow-x: auto;
  padding: 16px;
  border-radius: var(--radius);
  background: var(--code);
  color: #e8fff9;
  border: 1px solid #1b3834;
}
.article-body code { font-family: "SFMono-Regular", Consolas, "Liberation Mono", monospace; font-size: .92em; }
.article-body :not(pre) > code { background: #edf4f1; color: #163d38; padding: 2px 5px; border-radius: 4px; }
.article-body table { width: 100%; border-collapse: collapse; margin: 18px 0; font-size: 14px; }
.article-body th, .article-body td { border: 1px solid var(--line); padding: 9px 10px; vertical-align: top; }
.article-body th { background: #eef5f2; text-align: left; }
.article-body blockquote { margin: 18px 0; padding: 2px 0 2px 18px; border-left: 3px solid var(--accent); color: var(--muted); }
.article-body details { border: 1px solid var(--line); border-radius: var(--radius); padding: 12px 14px; margin: 14px 0; background: #fbfcfa; }
.article-body summary { cursor: pointer; font-weight: 700; }
.task-item { list-style: none; margin-left: -22px; }
.task-item input { margin-right: 8px; accent-color: var(--accent); }
.task-item label { cursor: pointer; }

.toc-panel {
  position: sticky;
  top: 24px;
  border: 1px solid var(--line);
  border-radius: var(--radius);
  background: rgba(255, 255, 255, .8);
  padding: 18px;
  max-height: calc(100vh - 48px);
  overflow-y: auto;
}
.toc-panel nav { display: grid; gap: 8px; margin-bottom: 22px; }
.toc-panel a {
  text-decoration: none;
  color: var(--muted);
  font-size: 13px;
  line-height: 1.35;
}
.toc-panel a:hover { color: var(--accent); }
.toc-level-3 { padding-left: 10px; }
.toc-level-4 { padding-left: 20px; }
.reading-stack { border-top: 1px solid var(--line); padding-top: 16px; }
.related-item { display: block; text-decoration: none; padding: 10px 0; border-bottom: 1px solid var(--line); }
.related-item strong { display: block; font-size: 14px; line-height: 1.35; }
.related-item span { color: var(--muted); font-size: 12px; }

.empty-state {
  grid-column: 1 / -1;
  border: 1px dashed var(--line-strong);
  border-radius: var(--radius);
  padding: 36px;
  color: var(--muted);
  background: rgba(255,255,255,.6);
}

@media (max-width: 1080px) {
  .app-shell { grid-template-columns: 1fr; }
  .sidebar {
    position: static;
    height: auto;
    border-right: 0;
    border-bottom: 1px solid var(--line);
  }
  .side-nav { grid-template-columns: repeat(3, minmax(0, 1fr)); }
  .topbar, .feature-row, .toolbar { flex-direction: column; align-items: stretch; }
  .topbar { display: grid; }
  .search-wrap { min-width: 0; }
  .feature-row { grid-template-columns: 1fr; }
  .doc-grid { grid-template-columns: repeat(2, minmax(0, 1fr)); }
  .article-layout { grid-template-columns: 1fr; }
  .toc-panel { position: static; max-height: none; }
  .editor-grid { grid-template-columns: 1fr; }
  .editor-grid textarea { border-right: 0; border-bottom: 1px solid var(--line); }
}

@media (max-width: 720px) {
  .main { padding: 18px 14px 42px; }
  .side-nav { grid-template-columns: 1fr 1fr; }
  .hero-card { grid-template-columns: 1fr; }
  .hero-card img { min-height: 180px; border-right: 0; border-bottom: 1px solid var(--line); }
  .hero-card div { padding: 22px; }
  .doc-grid { grid-template-columns: 1fr; }
  .toolbar { display: grid; }
  .search-wrap { display: grid; grid-template-columns: 1fr auto; }
  .article-actions, .editor-toolbar { align-items: stretch; flex-direction: column; }
  .draft-status { text-align: left; }
  .action-group { display: grid; grid-template-columns: 1fr; width: 100%; }
  .article-actions button, .editor-toolbar button { width: 100%; }
  .editor-grid, .editor-grid textarea, .editor-preview { min-height: 380px; }
}