:root {
  --bg: #ffffff;
  --bg-elev: #f7f8fa;
  --sidebar-bg: #f4f5f7;
  --border: #e3e6ea;
  --text: #1f2328;
  --text-muted: #656d76;
  --accent: #4f46e5;
  --accent-soft: #eef0fe;
  --code-bg: #f0f1f3;
  --sidebar-w: 280px;
  --max-read: 760px;
  --radius: 10px;
  --font: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, Helvetica, Arial, sans-serif;
  --mono: ui-monospace, SFMono-Regular, "SF Mono", Menlo, Consolas, monospace;
}

@media (prefers-color-scheme: dark) {
  :root {
    --bg: #1a1b1e;
    --bg-elev: #212327;
    --sidebar-bg: #161719;
    --border: #2d2f34;
    --text: #e6e6e6;
    --text-muted: #9aa0a6;
    --accent: #8b85ff;
    --accent-soft: #26244a;
    --code-bg: #2a2c31;
  }
}

* { box-sizing: border-box; }

html, body { margin: 0; padding: 0; }

body {
  font-family: var(--font);
  color: var(--text);
  background: var(--bg);
  line-height: 1.6;
  -webkit-font-smoothing: antialiased;
}

a { color: var(--accent); text-decoration: none; }
a:hover { text-decoration: underline; }

/* ---------- Layout ---------- */

.layout { display: flex; min-height: 100vh; }

.sidebar {
  width: var(--sidebar-w);
  flex: 0 0 var(--sidebar-w);
  background: var(--sidebar-bg);
  border-right: 1px solid var(--border);
  padding: 18px 14px 40px;
  position: sticky;
  top: 0;
  height: 100vh;
  overflow-y: auto;
}

.brand { padding: 4px 8px 16px; }
.brand-link {
  font-weight: 700;
  font-size: 1.05rem;
  color: var(--text);
}
.brand-link:hover { text-decoration: none; }

.content-wrap { flex: 1 1 auto; min-width: 0; display: flex; flex-direction: column; }

.topbar {
  display: flex;
  align-items: center;
  gap: 12px;
  padding: 12px 28px;
  border-bottom: 1px solid var(--border);
  background: var(--bg);
  position: sticky;
  top: 0;
  z-index: 5;
}
.topbar-spacer { flex: 1 1 auto; }
.account { display: flex; align-items: center; gap: 14px; }
.account-name { color: var(--text-muted); font-size: 0.9rem; }
.logout {
  font-size: 0.85rem;
  padding: 6px 12px;
  border: 1px solid var(--border);
  border-radius: 8px;
  color: var(--text);
}
.logout:hover { background: var(--bg-elev); text-decoration: none; }

.main { padding: 36px 28px 80px; flex: 1 1 auto; }

/* ---------- Sidebar nav tree ---------- */

.nav { font-size: 0.92rem; }
.project { margin-bottom: 6px; }
.project-name {
  cursor: pointer;
  font-weight: 600;
  padding: 6px 8px;
  border-radius: 6px;
  list-style: none;
  color: var(--text);
  text-transform: none;
}
.project-name::-webkit-details-marker { display: none; }
.project-name::before {
  content: "▸";
  display: inline-block;
  width: 1em;
  color: var(--text-muted);
  transition: transform .12s ease;
}
.project[open] > .project-name::before { transform: rotate(90deg); }
.project-name:hover { background: var(--bg-elev); }

ul.tree { list-style: none; margin: 2px 0 6px; padding-left: 14px; }
ul.tree ul.tree { padding-left: 12px; border-left: 1px solid var(--border); margin-left: 4px; }

.tree-doc a {
  display: block;
  padding: 4px 8px;
  border-radius: 6px;
  color: var(--text-muted);
}
.tree-doc a:hover { background: var(--bg-elev); color: var(--text); text-decoration: none; }
.tree-doc a.active { background: var(--accent-soft); color: var(--accent); font-weight: 600; }

.tree-folder summary {
  cursor: pointer;
  padding: 4px 8px;
  border-radius: 6px;
  color: var(--text);
  list-style: none;
  font-weight: 500;
}
.tree-folder summary::-webkit-details-marker { display: none; }
.tree-folder summary::before {
  content: "📁";
  margin-right: 6px;
  font-size: 0.85em;
}
.tree-folder summary:hover { background: var(--bg-elev); }
.empty-nav { color: var(--text-muted); padding: 8px; font-size: 0.9rem; }

/* ---------- Prose / document content ---------- */

.prose { max-width: var(--max-read); }
.prose h1 { font-size: 2rem; line-height: 1.2; margin: 0 0 0.6em; }
.prose h2 { font-size: 1.45rem; margin: 1.8em 0 0.5em; padding-bottom: .2em; border-bottom: 1px solid var(--border); }
.prose h3 { font-size: 1.18rem; margin: 1.5em 0 0.4em; }
.prose p, .prose li { font-size: 1rem; }
.prose ul, .prose ol { padding-left: 1.4em; }
.prose img { max-width: 100%; border-radius: var(--radius); }
.prose blockquote {
  margin: 1em 0;
  padding: 0.4em 1.1em;
  border-left: 3px solid var(--accent);
  background: var(--bg-elev);
  color: var(--text-muted);
  border-radius: 0 8px 8px 0;
}
.prose code {
  font-family: var(--mono);
  font-size: 0.88em;
  background: var(--code-bg);
  padding: 0.15em 0.4em;
  border-radius: 5px;
}
.prose pre {
  background: var(--code-bg);
  padding: 16px 18px;
  border-radius: var(--radius);
  overflow-x: auto;
  border: 1px solid var(--border);
}
.prose pre code { background: none; padding: 0; font-size: 0.85rem; }
.prose table { border-collapse: collapse; width: 100%; margin: 1em 0; font-size: 0.95rem; }
.prose th, .prose td { border: 1px solid var(--border); padding: 8px 12px; text-align: left; }
.prose th { background: var(--bg-elev); }
.prose hr { border: none; border-top: 1px solid var(--border); margin: 2em 0; }

.lead { color: var(--text-muted); font-size: 1.05rem; }

.breadcrumb { font-size: 0.85rem; color: var(--text-muted); margin-bottom: 14px; }
.breadcrumb span { margin: 0 6px; opacity: 0.6; }

/* ---------- Home cards ---------- */

.card-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(220px, 1fr));
  gap: 16px;
  margin-top: 24px;
}
.project-card {
  display: flex;
  flex-direction: column;
  gap: 6px;
  padding: 20px;
  border: 1px solid var(--border);
  border-radius: var(--radius);
  background: var(--bg-elev);
  color: var(--text);
  transition: border-color .12s ease, transform .12s ease;
}
.project-card:hover { border-color: var(--accent); transform: translateY(-2px); text-decoration: none; }
.project-card-title { font-weight: 600; font-size: 1.1rem; }
.project-card-meta { color: var(--text-muted); font-size: 0.85rem; }

.doc-list { line-height: 2; }

/* ---------- Login ---------- */

.login-body {
  display: flex;
  align-items: center;
  justify-content: center;
  min-height: 100vh;
  background: var(--sidebar-bg);
  padding: 20px;
}
.login-card {
  width: 100%;
  max-width: 380px;
  background: var(--bg);
  border: 1px solid var(--border);
  border-radius: 14px;
  padding: 36px 32px;
  box-shadow: 0 8px 30px rgba(0,0,0,0.06);
}
.login-brand { text-align: center; font-weight: 700; margin-bottom: 18px; }
.login-card h1 { font-size: 1.3rem; margin: 0 0 20px; text-align: center; }
.login-form { display: flex; flex-direction: column; gap: 16px; }
.login-form label { display: flex; flex-direction: column; gap: 6px; font-size: 0.85rem; color: var(--text-muted); }
.login-form input {
  padding: 10px 12px;
  border: 1px solid var(--border);
  border-radius: 8px;
  font-size: 1rem;
  background: var(--bg);
  color: var(--text);
}
.login-form input:focus { outline: 2px solid var(--accent); outline-offset: 0; border-color: var(--accent); }
.login-form button {
  margin-top: 6px;
  padding: 11px;
  border: none;
  border-radius: 8px;
  background: var(--accent);
  color: #fff;
  font-size: 1rem;
  font-weight: 600;
  cursor: pointer;
}
.login-form button:hover { filter: brightness(1.05); }
.form-error {
  background: #fdecea;
  color: #b3261e;
  padding: 10px 14px;
  border-radius: 8px;
  font-size: 0.9rem;
  margin-bottom: 16px;
}
@media (prefers-color-scheme: dark) {
  .form-error { background: #3a1f1d; color: #ff9a92; }
}

/* ---------- Mobile ---------- */

.nav-toggle, .hamburger { display: none; }

@media (max-width: 800px) {
  .sidebar {
    position: fixed;
    left: 0; top: 0;
    transform: translateX(-100%);
    transition: transform .2s ease;
    z-index: 20;
    box-shadow: 2px 0 16px rgba(0,0,0,0.15);
  }
  .nav-toggle:checked ~ .layout .sidebar { transform: translateX(0); }
  .hamburger {
    display: inline-block;
    cursor: pointer;
    font-size: 1.3rem;
    line-height: 1;
  }
  .main { padding: 24px 18px 60px; }
}