:root {
  --bg: #f6f7f9; --card: #fff; --ink: #1c2330; --muted: #667085;
  --accent: #0b57d0; --accent-ink: #fff; --line: #e3e6ea; --mark: #ffe27a;
}
@media (prefers-color-scheme: dark) {
  :root {
    --bg: #12161d; --card: #1b212b; --ink: #e8ecf2; --muted: #94a0b0;
    --accent: #6ea8ff; --accent-ink: #0b1220; --line: #2a3240; --mark: #7a6414;
  }
}
* { box-sizing: border-box; }
body {
  margin: 0; background: var(--bg); color: var(--ink);
  font: 16px/1.55 system-ui, -apple-system, "Segoe UI", Roboto, sans-serif;
}
a { color: var(--accent); text-decoration: none; }
a:hover { text-decoration: underline; }
mark { background: var(--mark); color: inherit; border-radius: 2px; padding: 0 1px; }

.topbar {
  display: flex; flex-wrap: wrap; gap: .6rem; align-items: center;
  padding: .6rem .9rem; background: var(--card); border-bottom: 1px solid var(--line);
  position: sticky; top: 0; z-index: 10;
}
.brand { font-weight: 700; font-size: 1.05rem; white-space: nowrap; }
.searchbar { display: flex; flex: 1 1 260px; gap: .4rem; min-width: 200px; }
.searchbar input {
  flex: 1; padding: .55rem .7rem; border: 1px solid var(--line); border-radius: 8px;
  background: var(--bg); color: var(--ink); font-size: 1rem;
}
.searchbar button, .login-card button {
  padding: .55rem 1rem; border: 0; border-radius: 8px; background: var(--accent);
  color: var(--accent-ink); font-size: 1rem; cursor: pointer;
}
.topbar nav a { padding: .5rem .6rem; font-weight: 600; }

main { max-width: 900px; margin: 0 auto; padding: 1rem; }
h1 { font-size: 1.35rem; margin: .5rem 0; }
.muted { color: var(--muted); }
.tags {
  font-size: .72rem; background: var(--accent); color: var(--accent-ink);
  border-radius: 99px; padding: .1rem .5rem; margin-left: .3rem; white-space: nowrap;
}

.card-grid { display: grid; grid-template-columns: repeat(auto-fill, minmax(240px, 1fr)); gap: .6rem; }
.card {
  display: flex; flex-direction: column; gap: .2rem; padding: .8rem .9rem;
  background: var(--card); border: 1px solid var(--line); border-radius: 10px;
}
.card:hover { border-color: var(--accent); text-decoration: none; }
.card-title { font-weight: 600; color: var(--ink); }
.card-meta { font-size: .8rem; color: var(--muted); }

.result {
  display: block; padding: .7rem .9rem; margin: .5rem 0; background: var(--card);
  border: 1px solid var(--line); border-radius: 10px; color: var(--ink);
}
.result:hover { border-color: var(--accent); text-decoration: none; }
.result-top { display: flex; flex-wrap: wrap; gap: .5rem; align-items: baseline; }
.result-section { font-weight: 600; }
.result-page { color: var(--muted); font-size: .85rem; }
.snippet { margin: .3rem 0 0; color: var(--muted); font-size: .92rem; }

.tree { background: var(--card); border: 1px solid var(--line); border-radius: 10px;
        margin: .4rem 0; padding: .5rem .8rem; }
.tree summary { cursor: pointer; font-weight: 600; padding: .3rem 0; }
.tree ul { margin: .2rem 0 .4rem; padding-left: 1.1rem; }
.tree li { margin: .25rem 0; }

.crumbs { font-size: .85rem; color: var(--muted); margin-top: .3rem; }
.pager { display: flex; flex-wrap: wrap; gap: .9rem; margin: 1rem 0; align-items: center; }
.pager a { font-weight: 600; padding: .4rem 0; }

.page { background: var(--card); border: 1px solid var(--line); border-radius: 10px;
        padding: .9rem 1rem; margin: .8rem 0; }
.page-num { font-size: .78rem; color: var(--muted); border-bottom: 1px solid var(--line);
            padding-bottom: .3rem; margin-bottom: .5rem; }
.page-text { white-space: pre-wrap; overflow-wrap: anywhere; font-size: .95rem; }
figure { margin: .8rem 0; text-align: center; }
figure img { max-width: 100%; height: auto; border: 1px solid var(--line);
             border-radius: 6px; background: #fff; }

footer { text-align: center; color: var(--muted); font-size: .8rem; padding: 1.2rem; }

.login-body { display: grid; place-items: center; min-height: 100vh; margin: 0;
              background: var(--bg); font: 16px system-ui, sans-serif; color: var(--ink); }
.login-card { display: flex; flex-direction: column; gap: .8rem; width: min(320px, 90vw);
              background: var(--card); border: 1px solid var(--line); border-radius: 12px;
              padding: 1.5rem; text-align: center; }
.login-card input { padding: .6rem .7rem; border: 1px solid var(--line); border-radius: 8px;
                    background: var(--bg); color: var(--ink); font-size: 1rem; }
.error { color: #d33; margin: 0; }