:root {
  --bg: #f4f5f7; --card: #ffffff; --fg: #1c1f24; --muted: #6a717d; --line: #e2e5ea;
  --accent: #2f6fde; --accent-fg: #ffffff; --mark: #ffe58a;
  --del-bg: #fdecec; --del: #c62828; --edit-bg: #e6eefc; --edit: #2a5bb8;
  --ins-bg: #dcf5e3; --ins: #1d6b35; --bar: #7aa2ea; --bar-del: #d9534f;
  color-scheme: light;
}
@media (prefers-color-scheme: dark) {
  :root {
    --bg: #111317; --card: #1a1d23; --fg: #e4e7ec; --muted: #9aa1ad; --line: #2b3038;
    --accent: #5b8ff0; --accent-fg: #0d1117; --mark: #6b5a12;
    --del-bg: #351c1d; --del: #ff7b72; --edit-bg: #1b2a44; --edit: #8db4ff;
    --ins-bg: #173322; --ins: #7ee2a0; --bar: #4f79c9; --bar-del: #e5605b;
    color-scheme: dark;
  }
}

* { box-sizing: border-box; }
body { margin: 0; background: var(--bg); color: var(--fg);
       font: 15px/1.5 system-ui, -apple-system, "Segoe UI", Roboto, sans-serif; }
a { color: var(--accent); text-decoration: none; }
a:hover { text-decoration: underline; }
main { max-width: 860px; margin: 0 auto; padding: 16px; }
main.center { min-height: 80vh; display: grid; place-items: center; }
h1 { font-size: 1.4rem; margin: 0 0 12px; }
h2 { font-size: 1.05rem; margin: 0 0 10px; }
h3 { font-size: .95rem; margin: 14px 0 6px; }
pre { overflow-x: auto; font-size: 12px; background: var(--bg); padding: 10px; border-radius: 6px; }
.muted { color: var(--muted); font-size: 13px; }
.empty { color: var(--muted); text-align: center; padding: 24px 0; }

/* top bar */
.topbar { position: sticky; top: 0; z-index: 5; display: flex; align-items: center; gap: 16px;
          padding: 8px 16px; background: var(--card); border-bottom: 1px solid var(--line); }
.brand { font-weight: 700; color: var(--fg); }
.topbar nav { display: flex; gap: 4px; flex: 1; overflow-x: auto; }
.topbar nav a { padding: 6px 10px; border-radius: 6px; color: var(--fg); white-space: nowrap; }
.topbar nav a[aria-current="page"] { background: var(--edit-bg); color: var(--edit); }
.logout { margin: 0; }

/* forms */
input, select, button, .button { font: inherit; color: var(--fg); background: var(--card);
  border: 1px solid var(--line); border-radius: 6px; padding: 6px 9px; min-height: 34px; }
input:focus, select:focus { outline: 2px solid var(--accent); outline-offset: -1px; }
button, .button { cursor: pointer; display: inline-flex; align-items: center; }
button.primary { background: var(--accent); color: var(--accent-fg); border-color: var(--accent); }
button.link { border: 0; background: none; color: var(--muted); padding: 4px; min-height: 0; }
.card { background: var(--card); border: 1px solid var(--line); border-radius: 10px; padding: 14px 16px; margin: 12px 0; }
.login { width: min(360px, 100%); display: grid; gap: 12px; }
.login label { display: grid; gap: 4px; font-size: 13px; color: var(--muted); }
.error { color: var(--del); background: var(--del-bg); padding: 8px 10px; border-radius: 6px; margin: 0; }

.filters { display: flex; flex-wrap: wrap; gap: 8px 10px; align-items: end; background: var(--card);
           border: 1px solid var(--line); border-radius: 10px; padding: 12px; }
.filters label { display: grid; gap: 3px; font-size: 12px; color: var(--muted); min-width: 0; }
.filters label.grow { flex: 1 1 100%; }
.filters select { max-width: 230px; }
.filters .actions { display: flex; gap: 6px; }
.filters .hint { flex-basis: 100%; margin: 0; font-size: 11px; color: var(--muted); }
.summary { color: var(--muted); font-size: 13px; margin: 12px 2px 4px; }

/* message cards */
.msg { background: var(--card); border: 1px solid var(--line); border-radius: 10px; padding: 12px 14px; margin: 10px 0; }
.msg.deleted { background: var(--del-bg); border-left: 4px solid var(--del); }
.msg header { display: flex; flex-wrap: wrap; gap: 4px 10px; align-items: baseline; font-size: 13px; }
.msg .sender { font-weight: 600; }
.msg .chan { color: var(--muted); }
.msg .when { margin-left: auto; color: var(--muted); }
.msg footer { margin-top: 6px; }
.msg img, .msg video { display: block; max-width: 100%; max-height: 480px; border-radius: 8px; margin-top: 8px; }
.msg audio { width: 100%; margin-top: 8px; }
.msg .file { display: inline-block; margin-top: 8px; }
.badges:empty { display: none; }
.badges { display: flex; flex-wrap: wrap; gap: 4px; margin: 4px 0; }
.badge { font-size: 11.5px; padding: 1px 8px; border-radius: 10px; background: var(--bg); color: var(--muted); }
.badge.del { background: var(--del); color: #fff; }
.badge.edit { background: var(--edit-bg); color: var(--edit); }
.text { white-space: pre-wrap; overflow-wrap: anywhere; margin-top: 4px; }
mark { background: var(--mark); color: inherit; border-radius: 2px; padding: 0 1px; }
.pager { display: flex; justify-content: center; align-items: center; gap: 12px; margin: 18px 0; color: var(--muted); }

/* detail */
.meta dl { display: grid; grid-template-columns: max-content 1fr; gap: 4px 14px; margin: 0; font-size: 14px; }
.meta dt { color: var(--muted); }
.meta dd { margin: 0; overflow-wrap: anywhere; }
dd.del { color: var(--del); }
blockquote { margin: 0; padding: 6px 10px; border-left: 3px solid var(--line); color: var(--muted); }
.versions { padding-left: 20px; margin: 0; }
.versions li { margin-bottom: 14px; }
.versions header { font-size: 13px; }
.diff del { background: var(--del-bg); color: var(--del); }
.diff ins { background: var(--ins-bg); color: var(--ins); text-decoration: none; }
details summary { cursor: pointer; color: var(--muted); }

/* gallery */
.grid { display: grid; grid-template-columns: repeat(auto-fill, minmax(150px, 1fr)); gap: 8px; margin-top: 8px; }
.tile { position: relative; display: block; aspect-ratio: 1; overflow: hidden; border-radius: 8px;
        background: var(--card); border: 1px solid var(--line); }
.tile img, .tile video { width: 100%; height: 100%; object-fit: cover; display: block; }
.tile.deleted { outline: 3px solid var(--del); outline-offset: -3px; }
.tile .badge.del { position: absolute; top: 6px; left: 6px; }
.tile .cap { position: absolute; bottom: 0; left: 0; right: 0; padding: 2px 6px; font-size: 11px;
             color: #fff; background: linear-gradient(transparent, rgba(0,0,0,.6)); }
.tile .play { position: absolute; inset: 0; display: grid; place-items: center; font-size: 30px; color: #fff;
              text-shadow: 0 1px 6px rgba(0,0,0,.7); pointer-events: none; }
.tile .doc { display: grid; place-items: center; height: 100%; padding: 8px; font-size: 12px; text-align: center;
             overflow-wrap: anywhere; color: var(--fg); }

/* stats */
.tiles { display: grid; grid-template-columns: repeat(auto-fit, minmax(150px, 1fr)); gap: 8px; margin: 12px 0 4px; }
.tile-stat { background: var(--card); border: 1px solid var(--line); border-radius: 10px; padding: 12px 14px;
             display: grid; color: var(--fg); }
.tile-stat:hover { text-decoration: none; border-color: var(--accent); }
.tile-stat b { font-size: 1.5rem; font-variant-numeric: tabular-nums; }
.tile-stat span { color: var(--muted); font-size: 13px; }
.tile-stat.del b { color: var(--del); }
.chart { width: 100%; height: auto; display: block; }
.chart .bar, .hbar .bar, .key.bar { fill: var(--bar); background: var(--bar); }
.chart .bar-del, .key.bar-del { fill: var(--bar-del); background: var(--bar-del); }
.chart .hit { fill: transparent; }
.chart g:hover .bar { fill: var(--accent); }
.chart .axis { stroke: var(--line); }
.chart .tick { fill: var(--muted); font-size: 11px; }
.legend { font-size: 12px; color: var(--muted); margin: -4px 0 8px; display: flex; align-items: center; gap: 6px; }
.key { display: inline-block; width: 10px; height: 10px; border-radius: 2px; }
.two-col { display: grid; grid-template-columns: 1fr 1fr; gap: 0 12px; }
.rank { width: 100%; border-collapse: collapse; font-size: 14px; }
.rank td { padding: 4px 4px; border-bottom: 1px solid var(--line); }
.rank tr:last-child td { border-bottom: 0; }
.rank .num { text-align: right; font-variant-numeric: tabular-nums; white-space: nowrap; }
.rank .num.del { color: var(--del); font-size: 12px; }
.rank .barcell { width: 35%; }
.hbar { width: 100%; height: 6px; display: block; }
.hbar .track { fill: var(--bg); }

@media (max-width: 640px) {
  main { padding: 10px 12px; }
  .topbar { gap: 8px; padding: 8px 12px; }
  .filters label { flex: 1 1 calc(50% - 10px); }
  .filters select { max-width: none; width: 100%; }
  .filters input[type="date"] { width: 100%; }
  .two-col { grid-template-columns: 1fr; }
  .grid { grid-template-columns: repeat(auto-fill, minmax(105px, 1fr)); }
  .meta dl { grid-template-columns: 1fr; }
  .meta dt { margin-top: 6px; }
}