:root {
  color-scheme: light;
  --bg: #f5f2eb;
  --surface: #fffdf8;
  --surface-raised: #ffffff;
  --text: #23211d;
  --muted: #78736a;
  --border: #ddd8ce;
  --accent: #d85f3d;
  --accent-dark: #b94729;
  --sidebar: #efebe3;
  --code-bg: #252522;
  --shadow: 0 14px 45px rgb(46 38 27 / 12%);
  --serif: Georgia, "Noto Serif SC", "Songti SC", serif;
  --sans: Inter, ui-sans-serif, -apple-system, BlinkMacSystemFont, "Segoe UI", sans-serif;
}

html[data-theme="dark"] {
  color-scheme: dark;
  --bg: #191a18;
  --surface: #20211e;
  --surface-raised: #292a26;
  --text: #ece9e1;
  --muted: #a8a399;
  --border: #3d3e39;
  --accent: #ed7957;
  --accent-dark: #ff9475;
  --sidebar: #1c1d1a;
  --code-bg: #141512;
  --shadow: 0 14px 45px rgb(0 0 0 / 28%);
}

* { box-sizing: border-box; }
html { scroll-behavior: smooth; }

body {
  margin: 0;
  min-width: 320px;
  min-height: 100vh;
  overflow: hidden;
  background: var(--bg);
  color: var(--text);
  font-family: var(--sans);
}

button, textarea { font: inherit; }
button { color: inherit; }

.topbar {
  position: relative;
  z-index: 15;
  height: 68px;
  display: grid;
  grid-template-columns: 1fr auto 1fr;
  align-items: center;
  gap: 20px;
  padding: 0 22px;
  border-bottom: 1px solid var(--border);
  background: color-mix(in srgb, var(--surface) 94%, transparent);
  backdrop-filter: blur(16px);
}

.brand { display: inline-flex; width: fit-content; align-items: center; gap: 11px; color: var(--text); text-decoration: none; }
.brand-mark { display: grid; width: 36px; height: 36px; place-items: center; border-radius: 10px 10px 10px 3px; background: var(--accent); color: #fff; font-family: var(--serif); font-size: 21px; font-weight: 700; }
.brand strong, .brand small { display: block; }
.brand strong { font-family: var(--serif); font-size: 17px; letter-spacing: .08em; }
.brand small { margin-top: 1px; color: var(--muted); font-size: 9px; letter-spacing: .12em; text-transform: uppercase; }
.document-name { max-width: 34vw; overflow: hidden; color: var(--muted); font-size: 13px; text-overflow: ellipsis; white-space: nowrap; }
.actions { display: flex; justify-content: flex-end; gap: 8px; }

.button, .icon-button, .small-add {
  border: 1px solid var(--border);
  background: var(--surface-raised);
  cursor: pointer;
  transition: transform .16s ease, border-color .16s ease, background .16s ease;
}
.button:hover, .icon-button:hover, .small-add:hover { transform: translateY(-1px); border-color: var(--accent); }
.button:focus-visible, .icon-button:focus-visible, .small-add:focus-visible, textarea:focus-visible, .document-item:focus-visible { outline: 2px solid var(--accent); outline-offset: 2px; }
.button { min-height: 38px; padding: 0 15px; border-radius: 9px; font-size: 13px; font-weight: 650; }
.button-primary { border-color: var(--accent); background: var(--accent); color: #fff; }
.button-primary:hover { border-color: var(--accent-dark); background: var(--accent-dark); }
.button-quiet[aria-expanded="true"] { border-color: var(--accent); color: var(--accent); }
.icon-button { width: 38px; height: 38px; border-radius: 9px; font-size: 18px; }
.small-add { width: 30px; height: 30px; border-radius: 8px; color: var(--accent); font-size: 18px; }

.workspace {
  display: grid;
  grid-template-columns: 238px minmax(420px, 1fr) 250px;
  height: calc(100vh - 68px);
}

.library-panel, .toc-panel, .reader-panel { min-width: 0; min-height: 0; }
.library-panel, .toc-panel { display: flex; flex-direction: column; background: var(--sidebar); }
.library-panel { border-right: 1px solid var(--border); }
.toc-panel { border-left: 1px solid var(--border); }
.reader-panel { display: flex; flex-direction: column; background: var(--surface); }

.side-heading, .reader-heading, .editor-heading {
  display: flex;
  min-height: 82px;
  align-items: center;
  justify-content: space-between;
  padding: 16px 20px;
  border-bottom: 1px solid var(--border);
}
.reader-heading { padding-inline: clamp(28px, 5vw, 70px); }
.eyebrow { color: var(--accent); font-size: 9px; font-weight: 800; letter-spacing: .17em; text-transform: uppercase; }
.side-heading h1, .reader-heading h1, .editor-heading h2 { margin: 4px 0 0; font-family: var(--serif); }
.side-heading h1 { font-size: 20px; }
.reader-heading h1 { max-width: 45vw; overflow: hidden; font-size: 21px; text-overflow: ellipsis; white-space: nowrap; }
.reader-meta { display: flex; gap: 14px; color: var(--muted); font-size: 11px; }

.document-list { flex: 1; overflow-y: auto; padding: 12px 10px; }
.document-item { position: relative; display: grid; grid-template-columns: 1fr 24px; width: 100%; align-items: center; gap: 5px; margin-bottom: 5px; padding: 11px 8px 11px 12px; border: 1px solid transparent; border-radius: 9px; background: transparent; color: var(--muted); text-align: left; cursor: pointer; }
.document-item:hover { background: color-mix(in srgb, var(--surface-raised) 65%, transparent); color: var(--text); }
.document-item.active { border-color: color-mix(in srgb, var(--accent) 35%, var(--border)); background: var(--surface-raised); color: var(--text); box-shadow: 0 4px 18px rgb(40 34 25 / 6%); }
.document-item.active::before { position: absolute; top: 12px; bottom: 12px; left: -1px; width: 3px; border-radius: 0 3px 3px 0; background: var(--accent); content: ""; }
.document-info { min-width: 0; }
.document-info strong { display: block; overflow: hidden; font-size: 12px; font-weight: 650; text-overflow: ellipsis; white-space: nowrap; }
.document-info small { display: block; margin-top: 4px; color: var(--muted); font-size: 9px; }
.document-close { display: grid; width: 23px; height: 23px; place-items: center; border: 0; border-radius: 6px; background: transparent; color: transparent; cursor: pointer; }
.document-item:hover .document-close, .document-item.active .document-close { color: var(--muted); }
.document-close:hover { background: var(--sidebar); color: var(--accent) !important; }
.library-tip { padding: 13px 15px; border-top: 1px solid var(--border); color: var(--muted); font-size: 9px; line-height: 1.5; }

.reading-area { position: relative; flex: 1; min-height: 0; overflow: auto; scroll-behavior: smooth; }
.markdown-body { width: min(780px, calc(100% - 72px)); min-height: 100%; margin: 0 auto; padding: 48px 0 110px; font-family: var(--serif); font-size: 17px; line-height: 1.85; }
.markdown-body h1, .markdown-body h2, .markdown-body h3, .markdown-body h4 { scroll-margin-top: 25px; margin: 1.7em 0 .65em; line-height: 1.25; }
.markdown-body h1 { margin-top: 0; font-size: clamp(32px, 4vw, 48px); letter-spacing: -.035em; }
.markdown-body h2 { padding-bottom: .35em; border-bottom: 1px solid var(--border); font-size: 28px; }
.markdown-body h3 { font-size: 21px; }
.markdown-body p { margin: 1em 0; }
.markdown-body a { color: var(--accent-dark); text-decoration-thickness: 1px; text-underline-offset: 3px; }
.markdown-body img { display: block; max-width: 100%; margin: 2em auto; border-radius: 10px; box-shadow: var(--shadow); }
.markdown-body hr { margin: 3em 0; border: 0; border-top: 1px solid var(--border); }
.markdown-body blockquote { margin: 1.5em 0; padding: .15em 1.25em; border-left: 3px solid var(--accent); color: var(--muted); }
.markdown-body ul, .markdown-body ol { padding-left: 1.5em; }
.markdown-body li + li { margin-top: .35em; }
.markdown-body code { border-radius: 5px; background: color-mix(in srgb, var(--accent) 10%, var(--surface)); padding: .18em .38em; font-family: "SFMono-Regular", Consolas, monospace; font-size: .84em; }
.markdown-body pre { overflow: auto; margin: 1.7em 0; padding: 20px; border-radius: 12px; background: var(--code-bg); box-shadow: var(--shadow); }
.markdown-body pre code { padding: 0; background: transparent; font-size: 13px; line-height: 1.7; }
.markdown-body table { display: block; width: 100%; overflow-x: auto; border-collapse: collapse; font-family: var(--sans); font-size: 14px; }
.markdown-body th, .markdown-body td { padding: 9px 12px; border: 1px solid var(--border); text-align: left; }
.markdown-body th { background: var(--sidebar); }

.toc { flex: 1; overflow-y: auto; padding: 14px 12px 40px; }
.toc:empty::before { display: block; padding: 10px; color: var(--muted); font-size: 11px; content: "当前文档没有标题"; }
.toc a { position: relative; display: block; margin: 1px 0; padding: 7px 9px; border-radius: 6px; color: var(--muted); font-size: 11px; line-height: 1.4; text-decoration: none; transition: color .15s ease, background .15s ease; }
.toc a:hover { background: var(--surface-raised); color: var(--text); }
.toc a.active { background: color-mix(in srgb, var(--accent) 10%, transparent); color: var(--accent-dark); font-weight: 700; }
.toc a.active::before { position: absolute; top: 9px; bottom: 9px; left: 0; width: 2px; border-radius: 2px; background: var(--accent); content: ""; }
.toc a[data-level="2"] { padding-left: 15px; }
.toc a[data-level="3"] { padding-left: 27px; }
.toc a[data-level="4"] { padding-left: 39px; font-size: 10px; }

.editor-drawer { position: fixed; z-index: 30; top: 68px; bottom: 0; left: 238px; display: flex; width: min(620px, calc(100vw - 238px)); flex-direction: column; border-right: 1px solid var(--border); background: var(--sidebar); box-shadow: var(--shadow); transform: translateX(calc(-100% - 238px)); transition: transform .22s ease; }
.editor-drawer.open { transform: translateX(0); }
.editor-heading { min-height: 82px; padding-inline: 24px; }
.editor-heading h2 { max-width: 440px; overflow: hidden; font-size: 20px; text-overflow: ellipsis; white-space: nowrap; }
#editor { width: 100%; flex: 1; resize: none; border: 0; outline: 0; padding: 28px 32px; background: transparent; color: var(--text); font-family: "SFMono-Regular", Consolas, "Liberation Mono", monospace; font-size: 14px; line-height: 1.8; tab-size: 2; }
.editor-footer { display: flex; justify-content: space-between; padding: 12px 24px; border-top: 1px solid var(--border); color: var(--muted); font-size: 10px; }
.drawer-backdrop { position: fixed; z-index: 25; inset: 68px 0 0; display: block; visibility: hidden; border: 0; background: rgb(0 0 0 / 18%); opacity: 0; cursor: default; transition: opacity .22s ease, visibility .22s; }
.drawer-backdrop.open { visibility: visible; opacity: 1; }

.drop-overlay { position: fixed; z-index: 50; inset: 0; display: grid; place-items: center; background: color-mix(in srgb, var(--bg) 82%, transparent); backdrop-filter: blur(8px); opacity: 0; pointer-events: none; transition: opacity .18s ease; }
.drop-overlay.visible { opacity: 1; }
.drop-overlay div { display: grid; min-width: 320px; place-items: center; gap: 8px; padding: 46px; border: 2px dashed var(--accent); border-radius: 18px; background: var(--surface); box-shadow: var(--shadow); }
.drop-overlay strong { font-family: var(--serif); font-size: 24px; }
.drop-overlay span { color: var(--muted); font-size: 11px; }

@media (max-width: 980px) {
  .workspace { grid-template-columns: 205px minmax(380px, 1fr) 210px; }
  .editor-drawer { left: 205px; width: min(600px, calc(100vw - 205px)); transform: translateX(calc(-100% - 205px)); }
  .editor-drawer.open { transform: translateX(0); }
}

@media (max-width: 760px) {
  body { overflow: auto; }
  .topbar { position: sticky; top: 0; grid-template-columns: 1fr auto; }
  .document-name { display: none; }
  .button-quiet { width: 38px; overflow: hidden; padding: 0; font-size: 0; }
  .button-quiet::before { font-size: 13px; content: "编辑"; }
  .button-primary { width: 38px; overflow: hidden; padding: 0; white-space: nowrap; color: transparent; }
  .button-primary span { color: #fff; font-size: 20px; }
  .workspace { display: grid; grid-template-columns: 150px minmax(320px, 1fr); height: calc(100vh - 68px); overflow-x: auto; }
  .toc-panel { display: none; }
  .side-heading { padding-inline: 13px; }
  .side-heading h1 { font-size: 17px; }
  .reader-heading { padding-inline: 22px; }
  .markdown-body { width: calc(100% - 40px); padding-top: 34px; }
  .editor-drawer { left: 0; width: min(100vw, 620px); transform: translateX(-105%); }
  .editor-drawer.open { transform: translateX(0); }
  .editor-footer span:last-child { display: none; }
}

@media print {
  .topbar, .library-panel, .toc-panel, .reader-heading, .editor-drawer, .drawer-backdrop { display: none !important; }
  body, .workspace, .reader-panel, .reading-area { display: block; height: auto; overflow: visible; background: #fff; color: #111; }
  .markdown-body { width: 100%; padding: 0; }
}