:root {
  --bg: #0a0e16;
  --panel: #111726;
  --panel-edge: #1d2638;
  --text: #dbe4f4;
  --muted: #7d8aa5;
  --accent: #4cc2ff;
  --accent-2: #9a7bff;
  --good: #46d39a;
  --warn: #ffb454;
  --bad: #ff6b81;
  --mono: "Cascadia Code", "JetBrains Mono", Consolas, monospace;
}

* { box-sizing: border-box; }

body {
  margin: 0;
  background: var(--bg);
  color: var(--text);
  font: 15px/1.55 system-ui, -apple-system, "Segoe UI", sans-serif;
}

a { color: var(--accent); text-decoration: none; }
a:hover { text-decoration: underline; }
.muted { color: var(--muted); }
.small { font-size: 0.85em; font-weight: 400; }
.nowrap { white-space: nowrap; }

.top {
  display: flex;
  justify-content: space-between;
  align-items: flex-start;
  gap: 16px;
  padding: 28px 32px 10px;
  max-width: 1400px;
  margin: 0 auto;
}
.top h1 { margin: 0; font-size: 28px; letter-spacing: 0.5px; }
.tagline { margin: 6px 0 0; color: var(--muted); max-width: 720px; }

.intro {
  max-width: 1400px;
  margin: 10px auto 0;
  padding: 0 32px;
}
.intro p {
  margin: 0;
  background: linear-gradient(90deg, rgba(76, 194, 255, 0.08), rgba(154, 123, 255, 0.05));
  border: 1px solid #1f3a55;
  border-left: 3px solid var(--accent);
  border-radius: 10px;
  padding: 14px 18px;
  color: #b9c8e2;
  font-size: 15px;
  line-height: 1.6;
}
.intro strong { color: var(--text); }

.scenarios {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 10px;
}
@media (max-width: 560px) { .scenarios { grid-template-columns: 1fr; } }
.scenario-btn {
  text-align: left;
  background: #14203a;
  border: 1px solid #28406e;
  border-radius: 10px;
  padding: 11px 13px;
  cursor: pointer;
  color: var(--text);
  font: inherit;
  transition: border-color 0.15s, transform 0.05s;
}
.scenario-btn:hover:not(:disabled) { border-color: var(--accent); }
.scenario-btn:active { transform: scale(0.99); }
.scenario-btn:disabled { opacity: 0.45; cursor: wait; }
.scenario-btn strong { display: block; font-size: 14.5px; margin-bottom: 2px; }
.scenario-btn span { font-size: 12.5px; color: var(--muted); }
.scenario-hint { margin: 10px 0 0; }

.takeaway {
  background: rgba(70, 211, 154, 0.07);
  border: 1px solid #245c45;
  border-left: 3px solid var(--good);
  border-radius: 8px;
  padding: 11px 14px;
  margin-bottom: 12px;
  font-size: 14px;
  line-height: 1.55;
  color: #c4e8d6;
}
.takeaway strong { color: var(--good); }

.grid {
  display: grid;
  grid-template-columns: minmax(380px, 1fr) minmax(380px, 1fr);
  gap: 18px;
  padding: 18px 32px 40px;
  max-width: 1400px;
  margin: 0 auto;
}
@media (max-width: 900px) { .grid { grid-template-columns: 1fr; } }

.col { display: flex; flex-direction: column; gap: 18px; min-width: 0; }

.panel {
  background: var(--panel);
  border: 1px solid var(--panel-edge);
  border-radius: 10px;
  padding: 14px 16px;
}
.panel-head {
  display: flex;
  justify-content: space-between;
  align-items: baseline;
  gap: 12px;
  flex-wrap: wrap;
  margin-bottom: 10px;
}
.panel h2 { margin: 0; font-size: 15px; letter-spacing: 0.4px; }

textarea {
  width: 100%;
  background: #0c1120;
  color: var(--text);
  border: 1px solid var(--panel-edge);
  border-radius: 8px;
  padding: 10px 12px;
  font-family: var(--mono);
  font-size: 14px;
  resize: vertical;
}
textarea:focus { outline: 1px solid var(--accent); }

.toolbar { display: flex; align-items: center; gap: 10px; margin-top: 10px; }
.hint { margin-left: auto; font-size: 12px; }

.btn {
  background: #18213a;
  color: var(--text);
  border: 1px solid var(--panel-edge);
  border-radius: 8px;
  padding: 7px 16px;
  font-size: 14px;
  cursor: pointer;
}
.btn:hover:not(:disabled) { border-color: var(--accent); }
.btn:disabled { opacity: 0.45; cursor: wait; }
.btn.primary { background: var(--accent); color: #04121f; font-weight: 600; border-color: transparent; }

.chips { display: flex; flex-wrap: wrap; gap: 7px; margin-top: 12px; }
.chip {
  background: transparent;
  color: var(--muted);
  border: 1px solid var(--panel-edge);
  border-radius: 999px;
  padding: 3px 12px;
  font-size: 12.5px;
  cursor: pointer;
  font-family: var(--mono);
}
.chip:hover { color: var(--accent); border-color: var(--accent); }

.results { overflow-x: auto; }
.results table { border-collapse: collapse; width: 100%; font-family: var(--mono); font-size: 13px; }
.results th, .results td { text-align: left; padding: 4px 12px 4px 0; white-space: nowrap; }
.results th { color: var(--accent); border-bottom: 1px solid var(--panel-edge); font-weight: 600; }
.results td.num { color: #b8e2ff; }
.results .rowcount { margin: 8px 0 0; font-size: 12.5px; color: var(--muted); }
.results .msg { color: var(--good); font-family: var(--mono); font-size: 13.5px; margin: 2px 0; }

.error {
  background: #2a1220;
  border: 1px solid #5c2030;
  color: var(--bad);
  border-radius: 8px;
  padding: 10px 12px;
  font-family: var(--mono);
  font-size: 13px;
  white-space: pre-wrap;
  margin-bottom: 10px;
}

.plan {
  margin: 0;
  font-family: var(--mono);
  font-size: 12.5px;
  white-space: pre-wrap;
  color: #c0d6f0;
}

.legend { display: flex; gap: 12px; font-size: 11.5px; color: var(--muted); flex-wrap: wrap; }
.legend .sw { display: inline-block; width: 10px; height: 10px; border-radius: 2px; margin-right: 4px; vertical-align: -1px; }
.sw.read { background: var(--accent); }
.sw.cached { background: #1d4a66; }
.sw.write { background: var(--warn); }
.sw.wal { background: var(--accent-2); }

.pagegrid {
  display: flex;
  flex-wrap: wrap;
  gap: 3px;
  padding: 6px 0 10px;
  min-height: 30px;
}
.page {
  width: 16px;
  height: 16px;
  border-radius: 3px;
  background: #161e30;
  border: 1px solid #1c2740;
  font-size: 8px;
  color: transparent;
  position: relative;
  transition: background 0.25s, box-shadow 0.25s;
}
.page:hover { color: var(--muted); }
.page:hover::after {
  content: attr(data-pid);
  position: absolute;
  top: -18px;
  left: 50%;
  transform: translateX(-50%);
  color: var(--text);
  background: #000;
  font-size: 10px;
  padding: 0 5px;
  border-radius: 4px;
}
.page.read { background: var(--accent); box-shadow: 0 0 8px var(--accent); }
.page.cached { background: #1d4a66; }
.page.write { background: var(--warn); box-shadow: 0 0 8px var(--warn); }

.iolog {
  font-family: var(--mono);
  font-size: 12px;
  max-height: 170px;
  overflow-y: auto;
  border-top: 1px solid var(--panel-edge);
  padding-top: 8px;
}
.iolog div { padding: 1px 0; }
.iolog .ev-read { color: #7fd0ff; }
.iolog .ev-cached { color: #4a7c9b; }
.iolog .ev-write { color: var(--warn); }
.iolog .ev-wal { color: var(--accent-2); }
.iolog .ev-note { color: var(--good); }

.tree { overflow-x: auto; }
.tree svg { display: block; margin: 0 auto; }
.tree .node rect { fill: #161e30; stroke: #2a3a5c; rx: 5px; }
.tree .node.leaf rect { stroke: #1d4a66; }
.tree .node.visited rect { stroke: var(--accent); stroke-width: 2; filter: drop-shadow(0 0 5px rgba(76, 194, 255, 0.6)); }
.tree text { fill: #c0d6f0; font-family: var(--mono); font-size: 10.5px; }
.tree .kind { fill: var(--muted); font-size: 9px; }
.tree .edge { stroke: #2a3a5c; fill: none; }
.tree .leafchain { stroke: #1d4a66; stroke-dasharray: 3 3; fill: none; }

.howto { margin: 0; padding-left: 18px; color: var(--muted); font-size: 13.5px; }
.howto li { margin-bottom: 7px; }
.howto strong { color: var(--text); }

.foot {
  border-top: 1px solid var(--panel-edge);
  padding: 18px 32px 30px;
  max-width: 1400px;
  margin: 0 auto;
  color: var(--muted);
  font-size: 13.5px;
}
.foot code { font-family: var(--mono); }