:root {
  --paper: #fbf7ef;
  --surface: #fffdf8;
  --ink: #27251f;
  --muted: #746f64;
  --line: #ddd5c7;
  --accent: #b95d3d;
  --accent-dark: #8e4028;
  --sage: #536b57;
  --danger: #a43f3f;
  --shadow: 0 18px 50px rgba(70, 55, 35, .10);
}

* { box-sizing: border-box; }
html {
  max-width: 100%;
  overflow-x: hidden;
  scroll-behavior: smooth;
}
body {
  width: 100%;
  max-width: 100%;
  overflow-x: hidden;
  margin: 0;
  background: var(--paper);
  color: var(--ink);
  font-family: "DM Sans", "Noto Sans SC", "Microsoft YaHei", sans-serif;
  line-height: 1.65;
}
button, input { font: inherit; }
button {
  border: 0;
  border-radius: 10px;
  padding: .72rem 1rem;
  background: var(--accent);
  color: white;
  font-weight: 700;
  cursor: pointer;
}
button:hover { background: var(--accent-dark); }
button:disabled { opacity: .55; cursor: not-allowed; }
.hidden { display: none !important; }
.muted { color: var(--muted); }
.eyebrow {
  margin: 0 0 .3rem;
  color: var(--accent);
  font-size: .72rem;
  font-weight: 800;
  letter-spacing: .12em;
}
.error { min-height: 1.5em; color: var(--danger); font-size: .9rem; }

.login-shell {
  min-height: 100vh;
  display: grid;
  place-items: center;
  padding: 1.5rem;
  background: radial-gradient(circle at 75% 20%, #f1dfc9 0, transparent 30%), var(--paper);
}
.login-card {
  width: min(430px, 100%);
  padding: 3rem;
  background: rgba(255, 253, 248, .92);
  border: 1px solid var(--line);
  border-radius: 24px;
  box-shadow: var(--shadow);
}
.login-card h1 {
  margin: .1rem 0 .5rem;
  font-family: "DM Serif Display", "Songti SC", serif;
  font-size: 2.3rem;
}
.login-card label { display: block; margin: .85rem 0 .35rem; font-weight: 700; }
.login-card input {
  width: 100%;
  padding: .78rem;
  border: 1px solid var(--line);
  border-radius: 10px;
  background: white;
  color: var(--ink);
}
.login-card button { width: 100%; margin-top: 1rem; }

.topbar {
  position: sticky;
  top: 0;
  z-index: 10;
  height: 68px;
  padding: 0 2rem;
  display: flex;
  align-items: center;
  justify-content: space-between;
  background: var(--surface);
  border-bottom: 1px solid var(--line);
}
.brand-mark {
  display: inline-grid;
  place-items: center;
  width: 34px;
  height: 34px;
  margin-right: .7rem;
  border-radius: 50%;
  background: var(--ink);
  color: var(--paper);
  font-family: "DM Serif Display", "Songti SC", serif;
}
.top-actions { display: flex; align-items: center; gap: .6rem; }
.quiet, .icon-btn { background: transparent; color: var(--ink); border: 1px solid var(--line); }
.quiet:hover, .icon-btn:hover { background: #f1eadf; }
.badge {
  padding: .28rem .6rem;
  border-radius: 99px;
  background: #e8efe7;
  color: var(--sage);
  font-size: .8rem;
  font-weight: 800;
}
.proposal-tabs {
  padding: 1rem 2rem;
  display: flex;
  gap: .75rem;
  background: var(--surface);
  border-bottom: 1px solid var(--line);
}
.proposal-tabs button { background: transparent; color: var(--muted); border: 1px solid var(--line); }
.proposal-tabs button.active { background: var(--ink); color: white; border-color: var(--ink); }

.app, .workspace, .content-panel, .markdown-body { min-width: 0; }
.app { max-width: 100%; overflow-x: hidden; }
.workspace {
  display: grid;
  grid-template-columns: 260px minmax(0, 1fr);
  width: 100%;
  max-width: 1400px;
  min-height: calc(100vh - 125px);
  margin: auto;
}
.sidebar {
  position: sticky;
  top: 125px;
  height: calc(100vh - 125px);
  padding: 1.5rem;
  overflow: auto;
  border-right: 1px solid var(--line);
}
.sidebar h2 { margin: .2rem 0 1rem; font-size: 1rem; }
.sidebar section + section { margin-top: 2rem; }
.section-title { display: flex; align-items: center; justify-content: space-between; }
.icon-btn { padding: .25rem .6rem; font-size: 1.1rem; }
.content-panel {
  min-width: 0;
  padding: 3rem clamp(1.5rem, 6vw, 6rem);
  background: var(--surface);
}
.document-head {
  display: flex;
  align-items: flex-end;
  justify-content: space-between;
  gap: 1rem;
  padding-bottom: 1.5rem;
  border-bottom: 1px solid var(--line);
}
.document-head h1 {
  margin: 0;
  font: 700 clamp(1.7rem, 3vw, 2.7rem) / 1.2 "DM Serif Display", "Songti SC", serif;
}

.markdown-body {
  width: 100%;
  max-width: 900px;
  overflow-wrap: anywhere;
  word-break: normal;
  font-size: 1rem;
}
.markdown-body p, .markdown-body li, .markdown-body .footnote { min-width: 0; }
.markdown-body a {
  color: var(--accent-dark);
  overflow-wrap: anywhere;
  word-break: break-word;
}
.markdown-body h1,
.markdown-body h2,
.markdown-body h3,
.markdown-body h4 {
  font-family: "DM Serif Display", "Songti SC", serif;
  line-height: 1.3;
  scroll-margin-top: 145px;
}
.markdown-body h1 { margin-top: 2.5rem; font-size: 2rem; }
.markdown-body h2 {
  margin-top: 2.3rem;
  padding-bottom: .4rem;
  border-bottom: 1px solid var(--line);
  font-size: 1.5rem;
}
.markdown-body h3 { margin-top: 1.8rem; font-size: 1.18rem; }
.markdown-body blockquote {
  margin: 1.4rem 0;
  padding: .8rem 1.2rem;
  border-left: 4px solid var(--accent);
  background: #faf0e5;
}
.markdown-body pre {
  max-width: 100%;
  overflow: auto;
  padding: 1rem;
  border-radius: 12px;
  background: #302e29;
  color: #f7f1e7;
}
.markdown-body code { font-family: "JetBrains Mono", monospace; }
.markdown-body table { width: 100%; max-width: 100%; border-collapse: collapse; display: block; overflow-x: auto; }
.markdown-body th, .markdown-body td { padding: .6rem .75rem; border: 1px solid var(--line); text-align: left; }
.markdown-body th { background: #f3ede3; }
.markdown-body a { color: var(--accent-dark); }
.math-display {
  width: 100%;
  max-width: 100%;
  min-width: 0;
  margin: 1.25rem 0;
  padding: .9rem 1rem;
  overflow-x: auto;
  text-align: center;
  background: #faf7f0;
  border: 1px solid var(--line);
  border-radius: 12px;
}
.math-inline { white-space: nowrap; }
.math-display mjx-container { margin: 0 !important; }

#toc a {
  display: block;
  padding: .32rem 0;
  color: var(--muted);
  text-decoration: none;
  font-size: .88rem;
}
#toc a.sub { padding-left: 1rem; }
#toc a:hover { color: var(--accent); }
.history-item { padding: .7rem 0; border-bottom: 1px solid var(--line); font-size: .84rem; }
.history-row { display: flex; justify-content: space-between; gap: .5rem; }
.history-actions button {
  margin: .4rem .25rem 0 0;
  padding: .25rem .45rem;
  background: transparent;
  color: var(--accent-dark);
  border: 1px solid var(--line);
  font-size: .75rem;
}
.warnings {
  padding: .8rem 1rem;
  margin: 1rem 0;
  background: #fff1d8;
  border: 1px solid #e8c987;
  border-radius: 10px;
  color: #704e13;
}
.warnings ul { margin: .3rem 0; padding-left: 1.2rem; }
.toast {
  position: fixed;
  right: 1.5rem;
  bottom: 1.5rem;
  z-index: 30;
  padding: .75rem 1rem;
  background: var(--ink);
  color: white;
  border-radius: 10px;
  box-shadow: var(--shadow);
}

@media (max-width: 900px) {
  .workspace { grid-template-columns: 220px minmax(0, 1fr); }
  .content-panel { padding: 2.5rem clamp(1.25rem, 4vw, 3rem); }
}

@media (max-width: 720px) {
  .topbar { padding: 0 1rem; }
  .top-actions .badge, .top-actions #downloadBtn { display: none; }
  .proposal-tabs { padding: .8rem 1rem; overflow: auto; }
  .workspace { display: flex; flex-direction: column; }
  .content-panel { order: 1; padding: 2rem 1.1rem; }
  .sidebar {
    order: 2;
    position: static;
    height: auto;
    border-top: 1px solid var(--line);
    border-right: 0;
    border-bottom: 0;
    background: var(--paper);
  }
  .sidebar section:first-child { display: none; }
  .content-panel, .sidebar { width: 100%; max-width: 100%; }
  .document-head { display: block; }
  .markdown-body a { word-break: break-all; }
  .markdown-body .footnote ol { padding-left: 1.25rem; }
  .markdown-body table, .markdown-body pre, .math-display {
    max-width: calc(100vw - 2.2rem);
  }
  .markdown-body table { font-size: .85rem; }
  .login-card { padding: 2rem; }
}