:root {
  --bg: #0b1020;
  --panel: #121a2b;
  --panel-2: #182238;
  --text: #e8eefc;
  --muted: #9fb0d0;
  --line: rgba(255,255,255,.08);
  --accent: #73a7ff;
  --accent-2: #4f7cff;
  --card: rgba(255,255,255,.04);
  --hover: rgba(115,167,255,.12);
}
* { box-sizing: border-box; }
html, body { height: 100%; }
body {
  margin: 0;
  font-family: "Microsoft YaHei", "PingFang SC", system-ui, sans-serif;
  color: var(--text);
  background: linear-gradient(180deg, #0a0f1d 0%, #0f1728 100%);
}
.app {
  display: grid;
  grid-template-columns: 360px 1fr;
  height: 100vh;
}
.sidebar {
  border-right: 1px solid var(--line);
  background: rgba(8, 12, 22, .88);
  backdrop-filter: blur(12px);
  overflow: auto;
}
body.focus-mode .app {
  grid-template-columns: 1fr;
}
body.focus-mode .sidebar {
  display: none;
}
.brand {
  padding: 22px 20px 12px;
  border-bottom: 1px solid var(--line);
}
.brand h1 {
  margin: 0;
  font-size: 22px;
}
.brand p {
  margin: 8px 0 0;
  color: var(--muted);
  font-size: 13px;
}
.toolbar {
  padding: 14px 16px;
  border-bottom: 1px solid var(--line);
}
.toolbar input {
  width: 100%;
  border: 1px solid var(--line);
  background: var(--panel);
  color: var(--text);
  border-radius: 12px;
  padding: 12px 14px;
  outline: none;
}
.toolbar-actions {
  display: flex;
  gap: 8px;
  margin-top: 10px;
}
.status-bar {
  margin-top: 10px;
  font-size: 12px;
  color: var(--muted);
  line-height: 1.5;
}
.nav {
  padding: 10px;
}
.group {
  margin-bottom: 12px;
  border: 1px solid var(--line);
  border-radius: 16px;
  background: var(--card);
  overflow: hidden;
}
.group-title {
  margin: 0;
  padding: 14px 16px;
  background: rgba(255,255,255,.03);
  font-size: 15px;
  border-bottom: 1px solid var(--line);
}
.group-meta {
  color: var(--muted);
  font-size: 12px;
  margin-left: 8px;
}
.item-list {
  display: flex;
  flex-direction: column;
}
.item {
  width: 100%;
  text-align: left;
  border: 0;
  border-bottom: 1px solid var(--line);
  background: transparent;
  color: var(--text);
  padding: 12px 16px;
  cursor: pointer;
}
.item:last-child { border-bottom: 0; }
.item:hover { background: var(--hover); }
.item.active {
  background: linear-gradient(90deg, rgba(79,124,255,.25), rgba(79,124,255,.08));
  color: #fff;
}
.item-title {
  display: block;
  font-size: 14px;
  margin-bottom: 4px;
}
.item-url {
  display: block;
  color: var(--muted);
  font-size: 11px;
  white-space: nowrap;
  overflow: hidden;
  text-overflow: ellipsis;
}
.main {
  display: grid;
  grid-template-rows: auto 1fr;
  min-width: 0;
}
.topbar {
  display: flex;
  justify-content: space-between;
  align-items: center;
  gap: 16px;
  padding: 18px 22px;
  border-bottom: 1px solid var(--line);
  background: rgba(10, 15, 29, .55);
  backdrop-filter: blur(12px);
}
.topbar h2 {
  margin: 0;
  font-size: 22px;
}
.topbar p {
  margin: 6px 0 0;
  color: var(--muted);
  font-size: 13px;
}
.actions {
  display: flex;
  gap: 10px;
  align-items: center;
}
.btn {
  border: 0;
  border-radius: 12px;
  padding: 11px 16px;
  background: var(--accent-2);
  color: white;
  text-decoration: none;
  cursor: pointer;
  font-size: 14px;
}
.btn.small {
  padding: 8px 12px;
  font-size: 13px;
}
.btn.secondary {
  background: rgba(255,255,255,.08);
  border: 1px solid var(--line);
}
.viewer-wrap {
  display: grid;
  grid-template-rows: auto 1fr;
  min-height: 0;
}
.notice {
  margin: 14px 18px 0;
  padding: 12px 14px;
  border: 1px solid rgba(255,255,255,.08);
  background: rgba(255,214,102,.08);
  color: #ffe8a3;
  border-radius: 12px;
  font-size: 13px;
}
#viewer {
  margin: 14px 18px 18px;
  width: calc(100% - 36px);
  height: calc(100% - 32px);
  border: 1px solid var(--line);
  border-radius: 18px;
  background: white;
}
body.focus-mode .main {
  grid-template-rows: auto 1fr;
}
body.focus-mode .topbar {
  padding: 10px 14px;
}
body.focus-mode .viewer-wrap {
  grid-template-rows: 1fr;
}
body.focus-mode .notice {
  display: none;
}
body.focus-mode #viewer {
  margin: 0;
  width: 100vw;
  height: calc(100vh - 64px);
  border-radius: 0;
  border: 0;
}
:fullscreen body.focus-mode,
html:fullscreen body.focus-mode {
  background: #000;
}
:fullscreen body.focus-mode .topbar,
html:fullscreen body.focus-mode .topbar {
  padding: 0;
  min-height: 0;
  border-bottom: 0;
  overflow: hidden;
}
:fullscreen body.focus-mode .topbar > *,
html:fullscreen body.focus-mode .topbar > * {
  display: none !important;
}
:fullscreen body.focus-mode .main,
html:fullscreen body.focus-mode .main {
  grid-template-rows: 1fr;
}
:fullscreen body.focus-mode .viewer-wrap,
html:fullscreen body.focus-mode .viewer-wrap {
  grid-template-rows: 1fr;
  height: 100vh;
}
:fullscreen body.focus-mode #viewer,
html:fullscreen body.focus-mode #viewer {
  margin: 0;
  width: 100vw;
  height: 100vh;
  border: 0;
  border-radius: 0;
}
.empty {
  padding: 18px 16px;
  color: var(--muted);
}
mark {
  background: rgba(255, 214, 102, .24);
  color: inherit;
  padding: 0 2px;
  border-radius: 4px;
}
@media (max-width: 900px) {
  .app { grid-template-columns: 1fr; grid-template-rows: 45vh 1fr; }
  .sidebar { border-right: 0; border-bottom: 1px solid var(--line); }
  .topbar { flex-direction: column; align-items: flex-start; }
  .actions { width: 100%; }
}