:root {
  --bg: #f7f8fa;
  --surface: #ffffff;
  --sidebar: #f1f3f6;
  --text: #172b4d;
  --muted: #5e6c84;
  --border: #dfe1e6;
  --accent: #0c66e4;
  --accent-hover: #0055cc;
  --accent-soft: #e9f2ff;
  --danger: #c9372c;
  --success-bg: #dcfff1;
  --success-text: #216e4e;
  --error-bg: #ffeceb;
  --error-text: #ae2e24;
  --warn-bg: #fff7d6;
  --warn-text: #7f5f01;
  --radius: 6px;
  --topbar-h: 52px;
  --sidebar-w: 290px;
  color-scheme: light;
}

@media (prefers-color-scheme: dark) {
  :root {
    --bg: #1d2125;
    --surface: #22272b;
    --sidebar: #1a1d20;
    --text: #dee4ea;
    --muted: #9fadbc;
    --border: #38414a;
    --accent: #579dff;
    --accent-hover: #85b8ff;
    --accent-soft: #1c2b41;
    --danger: #f87168;
    --success-bg: #1c3329;
    --success-text: #7ee2b8;
    --error-bg: #42221f;
    --error-text: #fd9891;
    --warn-bg: #3a2f10;
    --warn-text: #f8e6a0;
    color-scheme: dark;
  }
}

* { box-sizing: border-box; }

html, body { margin: 0; }

body {
  font: 15px/1.5 -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "Helvetica Neue", Arial, sans-serif;
  color: var(--text);
  background: var(--bg);
}

a { color: var(--accent); text-decoration: none; }
a:hover { text-decoration: underline; }
h1 { font-size: 1.7rem; margin: 0 0 .5rem; line-height: 1.25; }
h2 { font-size: 1.15rem; margin: 2rem 0 .75rem; }
code { font-family: ui-monospace, SFMono-Regular, Consolas, monospace; font-size: .9em; background: var(--accent-soft); padding: 1px 5px; border-radius: 4px; }
.muted { color: var(--muted); }
.small { font-size: .85rem; }

/* ----- top bar ----- */
.topbar {
  position: sticky; top: 0; z-index: 20;
  height: var(--topbar-h);
  display: flex; align-items: center; gap: 16px;
  padding: 0 16px;
  background: var(--surface);
  border-bottom: 1px solid var(--border);
}
.brand { font-weight: 700; font-size: 1.05rem; color: var(--text); white-space: nowrap; }
.brand:hover { text-decoration: none; }
.search { flex: 1; max-width: 440px; }
.search input { width: 100%; }
.usernav { margin-left: auto; display: flex; align-items: center; gap: 16px; white-space: nowrap; }
.usernav form { margin: 0; }
.sidebar-toggle { display: none; background: none; border: 0; font-size: 1.3rem; color: var(--text); cursor: pointer; padding: 4px; }

/* ----- shell ----- */
.shell { display: flex; min-height: calc(100vh - var(--topbar-h)); }
.main { flex: 1; min-width: 0; padding: 28px 40px 64px; max-width: 1200px; }

.sidebar {
  width: var(--sidebar-w); flex-shrink: 0;
  position: sticky; top: var(--topbar-h);
  height: calc(100vh - var(--topbar-h));
  overflow-y: auto;
  background: var(--sidebar);
  border-right: 1px solid var(--border);
  padding: 12px 8px 40px;
}
.sidebar-head {
  display: flex; align-items: center; justify-content: space-between;
  padding: 4px 8px 10px;
  font-size: .78rem; font-weight: 700; text-transform: uppercase; letter-spacing: .04em; color: var(--muted);
}

/* ----- page tree ----- */
.tree { list-style: none; margin: 0; padding: 0; }
.tree .tree { margin-left: 14px; padding-left: 6px; border-left: 1px solid var(--border); display: none; }
.tree-item.open > .tree { display: block; }
.tree-row { display: flex; align-items: center; gap: 2px; border-radius: var(--radius); padding: 1px 4px; }
.tree-row:hover { background: rgba(127, 127, 127, .12); }
.tree-row.active { background: var(--accent-soft); }
.tree-row.active .tree-link { color: var(--accent); font-weight: 600; }
.tree-toggle, .tree-spacer { width: 20px; height: 20px; flex-shrink: 0; }
.tree-toggle {
  border: 0; background: none; cursor: pointer; border-radius: 4px; padding: 0; color: var(--muted);
  display: inline-flex; align-items: center; justify-content: center;
}
.tree-toggle::before { content: "▸"; font-size: 12px; transition: transform .15s; }
.tree-item.open > .tree-row .tree-toggle::before { transform: rotate(90deg); }
.tree-toggle:hover { background: rgba(127, 127, 127, .2); }
.tree-link {
  flex: 1; min-width: 0; color: var(--text); padding: 4px 4px;
  overflow: hidden; text-overflow: ellipsis; white-space: nowrap; font-size: .92rem;
}
.tree-link:hover { text-decoration: none; }
.is-doc::before, .is-topic::before { display: inline-block; width: 1.3em; opacity: .75; }
.is-doc::before { content: "📄"; }
.is-topic::before { content: "📁"; }
.tree-link.no-content { color: var(--muted); }

/* ----- buttons & forms ----- */
.button {
  display: inline-flex; align-items: center; justify-content: center; gap: 4px;
  padding: 7px 14px; border-radius: var(--radius);
  border: 1px solid var(--border); background: var(--surface); color: var(--text);
  font: inherit; font-weight: 500; cursor: pointer; line-height: 1.2; white-space: nowrap;
}
.button:hover { text-decoration: none; background: var(--accent-soft); }
.button:disabled { opacity: .5; cursor: not-allowed; }
.button.primary { background: var(--accent); border-color: var(--accent); color: #fff; }
.button.primary:hover { background: var(--accent-hover); }
.button.danger { color: var(--danger); }
.button.danger:hover { background: var(--error-bg); }
.button.small { padding: 4px 10px; font-size: .85rem; }
.button.block { width: 100%; }
.link-button { background: none; border: 0; padding: 0; font: inherit; color: var(--accent); cursor: pointer; }
.link-button:hover { text-decoration: underline; }

input, select {
  font: inherit; color: var(--text); background: var(--surface);
  border: 1px solid var(--border); border-radius: var(--radius); padding: 7px 10px;
}
input:focus, select:focus, .button:focus-visible { outline: 2px solid var(--accent); outline-offset: 1px; }
input[type="file"] { padding: 8px; width: 100%; }
label { display: block; font-weight: 600; font-size: .9rem; margin-bottom: 14px; }
label input:not([type="checkbox"]):not([type="radio"]):not([type="color"]), label select { display: block; width: 100%; margin-top: 4px; font-weight: 400; }
label.checkbox { display: flex; align-items: center; gap: 8px; font-weight: 400; }
fieldset { border: 1px dashed var(--border); border-radius: var(--radius); padding: 12px 16px; margin: 0 0 16px; }
legend { font-weight: 600; font-size: .9rem; padding: 0 6px; }
.help { margin: 8px 0 0; }
.form { max-width: 720px; }
.form-actions { display: flex; gap: 8px; }

/* ----- cards, flash, misc ----- */
.card { background: var(--surface); border: 1px solid var(--border); border-radius: 8px; padding: 20px 24px; }
.card h2:first-child { margin-top: 0; }
.narrow { max-width: 480px; margin: 40px auto; }
.empty { text-align: center; padding: 40px 24px; }
.flash { padding: 10px 14px; border-radius: var(--radius); margin-bottom: 16px; }
.flash-success { background: var(--success-bg); color: var(--success-text); }
.flash-error { background: var(--error-bg); color: var(--error-text); }
.flash-warn { background: var(--warn-bg); color: var(--warn-text); }

.centered { min-height: 100vh; display: flex; align-items: center; justify-content: center; padding: 16px; }
.login-card { width: 100%; max-width: 380px; }
.login-card h1 { font-size: 1.4rem; }

.breadcrumbs { font-size: .85rem; color: var(--muted); margin-bottom: 10px; }
.breadcrumbs .sep { margin: 0 6px; opacity: .6; }

.page-header { display: flex; align-items: flex-start; justify-content: space-between; gap: 16px; flex-wrap: wrap; }
.actions { display: flex; flex-wrap: wrap; gap: 6px; align-items: center; }
.actions form { margin: 0; display: flex; gap: 4px; }
.meta { margin: 4px 0 20px; }

.doc-frame {
  display: block; width: 100%; min-height: 240px; height: 70vh;
  border: 1px solid var(--border); border-radius: 8px; background: #fff;
}

.child-list { list-style: none; padding: 0; margin: 0; }
.child-list li { padding: 8px 0; border-bottom: 1px solid var(--border); display: flex; gap: 12px; align-items: baseline; flex-wrap: wrap; }
.child-list li a { font-weight: 500; }

.topic-grid { display: grid; grid-template-columns: repeat(auto-fill, minmax(220px, 1fr)); gap: 12px; }
.topic-card { display: flex; flex-direction: column; gap: 4px; padding: 16px 18px; color: var(--text); }
.topic-card:hover { text-decoration: none; border-color: var(--accent); }

.search-results { list-style: none; padding: 0; }
.search-results li { padding: 12px 0; border-bottom: 1px solid var(--border); }
.search-results p { margin: 4px 0 0; color: var(--muted); }
mark { background: var(--warn-bg); color: var(--warn-text); padding: 0 2px; border-radius: 2px; }

.details { display: grid; grid-template-columns: max-content 1fr; gap: 8px 20px; margin: 16px 0; }
.details dt { font-weight: 600; color: var(--muted); }
.details dd { margin: 0; display: flex; align-items: center; gap: 8px; flex-wrap: wrap; }
.details.card { max-width: 480px; }
.secret { font-size: 1.05rem; padding: 4px 8px; }

/* ----- page form: content options + editor ----- */
.page-form { max-width: 1000px; }
.mode-options { display: grid; grid-template-columns: repeat(auto-fit, minmax(200px, 1fr)); gap: 8px; margin: 10px 0 16px; }
.mode-option {
  display: flex; gap: 10px; align-items: flex-start; margin: 0; cursor: pointer;
  padding: 10px 12px; border: 1px solid var(--border); border-radius: var(--radius); font-weight: 400;
}
.mode-option > span { display: flex; flex-direction: column; }
.mode-option input { margin-top: 4px; }
.mode-option.selected { border-color: var(--accent); background: var(--accent-soft); }
.mode-panel[hidden] { display: none; }

.editor { border: 1px solid var(--border); border-radius: 8px; }
.editor-toolbar {
  position: sticky; top: var(--topbar-h); z-index: 5;
  display: flex; flex-wrap: wrap; align-items: center; gap: 2px;
  padding: 6px; background: var(--sidebar); border-bottom: 1px solid var(--border); border-radius: 8px 8px 0 0;
}
.editor-toolbar button, .tb-color {
  min-width: 32px; height: 32px; padding: 0 6px; margin: 0;
  display: inline-flex; align-items: center; justify-content: center;
  border: 1px solid transparent; border-radius: 4px; background: none; color: var(--text);
  font: inherit; font-size: .95rem; cursor: pointer;
}
.editor-toolbar button:hover, .tb-color:hover { background: rgba(127, 127, 127, .18); }
.editor-toolbar button.active { background: var(--accent-soft); border-color: var(--accent); color: var(--accent); }
.editor-toolbar select { height: 32px; padding: 0 8px; }
.tb-sep { width: 1px; height: 22px; background: var(--border); margin: 0 4px; }
.tb-color { position: relative; font-weight: 700; }
.tb-color input { position: absolute; inset: 0; width: 100%; height: 100%; opacity: 0; cursor: pointer; border: 0; padding: 0; }
.tb-color span { border-bottom: 3px solid #c9372c; line-height: 1.1; }
.tb-highlight span { border-bottom-color: #f5cd47; }
.editor-area { position: relative; border-radius: 0 0 8px 8px; min-height: 420px; padding: 24px 32px; outline: none; cursor: text; }
.editor-area.is-empty::before { content: attr(data-placeholder); color: #8590a2; pointer-events: none; position: absolute; }

/* ----- admin ----- */
.inline-form { display: grid; grid-template-columns: repeat(auto-fit, minmax(170px, 1fr)); gap: 0 12px; align-items: end; }
.inline-form .button { margin-bottom: 14px; }
.table-wrap { overflow-x: auto; margin-top: 20px; }
.table { width: 100%; border-collapse: collapse; background: var(--surface); border: 1px solid var(--border); border-radius: 8px; }
.table th, .table td { text-align: left; padding: 10px 12px; border-bottom: 1px solid var(--border); vertical-align: middle; }
.table th { font-size: .78rem; text-transform: uppercase; letter-spacing: .04em; color: var(--muted); }
.row-form { display: flex; gap: 6px; margin: 0; }
.row-form select { padding: 4px 8px; }
.actions-cell { display: flex; flex-wrap: wrap; gap: 6px; }
.actions-cell form { margin: 0; }
.badge { display: inline-block; padding: 2px 8px; border-radius: 10px; font-size: .78rem; font-weight: 600; }
.badge-on { background: var(--success-bg); color: var(--success-text); }
.badge-off { background: var(--error-bg); color: var(--error-text); }
.badge-warn { background: var(--warn-bg); color: var(--warn-text); }

/* ----- small screens ----- */
@media (max-width: 860px) {
  .sidebar-toggle { display: block; }
  .main { padding: 20px 16px 48px; }
  .sidebar {
    position: fixed; left: 0; top: var(--topbar-h); z-index: 15;
    transform: translateX(-100%); transition: transform .2s;
    box-shadow: 4px 0 16px rgba(0, 0, 0, .15);
  }
  .sidebar-open .sidebar { transform: none; }
  .usernav { gap: 10px; font-size: .9rem; }
  .search { min-width: 80px; }
  .brand { display: none; }
}