:root {
  --bg: #f6f5f1;
  --card: #ffffff;
  --text: #1f2421;
  --muted: #5d6660;
  --border: #dcdcd4;
  --accent: #6b4f2a;
  --accent-soft: #efe6d8;
  --rosetta: #2f6db5;
  --hypres: #b5552f;
  --measured: #1f2421;
  --warn-bg: #fff4dc;
  --warn-text: #6b4a00;
  --error-bg: #fde8e6;
  --error-text: #8a1f12;
  --grid: #e7e6df;
  --radius: 10px;
}

@media (prefers-color-scheme: dark) {
  :root:not([data-theme="light"]) {
    --bg: #161816;
    --card: #1f221f;
    --text: #e9ebe7;
    --muted: #a3aba5;
    --border: #353a36;
    --accent: #d9b27c;
    --accent-soft: #3a3226;
    --rosetta: #7fb0ec;
    --hypres: #ee9a76;
    --measured: #e9ebe7;
    --warn-bg: #3a3017;
    --warn-text: #f3d58a;
    --error-bg: #431d18;
    --error-text: #ffb4a8;
    --grid: #2c302d;
  }
}

:root[data-theme="dark"] {
  --bg: #161816;
  --card: #1f221f;
  --text: #e9ebe7;
  --muted: #a3aba5;
  --border: #353a36;
  --accent: #d9b27c;
  --accent-soft: #3a3226;
  --rosetta: #7fb0ec;
  --hypres: #ee9a76;
  --measured: #e9ebe7;
  --warn-bg: #3a3017;
  --warn-text: #f3d58a;
  --error-bg: #431d18;
  --error-text: #ffb4a8;
  --grid: #2c302d;
}

* { box-sizing: border-box; }

body {
  margin: 0;
  background: var(--bg);
  color: var(--text);
  font: 15px/1.5 system-ui, -apple-system, "Segoe UI", Roboto, sans-serif;
}

.page-header, .page-footer { max-width: 1240px; margin: 0 auto; padding: 20px 16px 4px; }
.page-header h1 { margin: 0 0 4px; font-size: 1.6rem; }
.page-header p { margin: 0; color: var(--muted); }
.page-footer { padding-bottom: 32px; color: var(--muted); font-size: 0.9rem; }
.page-footer summary { cursor: pointer; color: var(--text); font-weight: 600; }

.layout {
  max-width: 1240px;
  margin: 0 auto;
  padding: 16px;
  display: grid;
  grid-template-columns: minmax(0, 1fr) minmax(0, 1fr);
  gap: 16px;
  align-items: start;
}

@media (max-width: 900px) {
  .layout { grid-template-columns: minmax(0, 1fr); }
}

.card {
  background: var(--card);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 16px;
  margin-bottom: 16px;
}

.sticky { position: sticky; top: 12px; }
@media (max-width: 900px) { .sticky { position: static; } }

h2 { font-size: 1.1rem; margin: 0 0 12px; display: flex; align-items: center; gap: 8px; }
h3 { font-size: 0.98rem; margin: 18px 0 4px; }

.step {
  display: inline-grid; place-items: center;
  width: 24px; height: 24px; border-radius: 50%;
  background: var(--accent); color: var(--card); font-size: 0.85rem;
}

.row { display: flex; flex-wrap: wrap; gap: 10px; align-items: flex-end; margin-top: 10px; }
.field { display: flex; flex-direction: column; gap: 4px; min-width: 0; }
.field.grow { flex: 1 1 120px; }
.field span { font-size: 0.85rem; color: var(--muted); }

input, select, button { font: inherit; color: inherit; }
input, select {
  background: var(--bg);
  border: 1px solid var(--border);
  border-radius: 7px;
  padding: 7px 9px;
  min-width: 0;
  width: 100%;
}
input:focus, select:focus, button:focus-visible { outline: 2px solid var(--accent); outline-offset: 1px; }
input[aria-invalid="true"] { border-color: var(--error-text); }

.check { display: flex; gap: 6px; align-items: center; padding: 7px 0; }
.check input { width: auto; }

.btn {
  background: var(--accent); color: var(--card);
  border: 0; border-radius: 7px; padding: 8px 14px; cursor: pointer; font-weight: 600;
}
.btn-secondary { background: var(--accent-soft); color: var(--text); margin-top: 8px; }
.btn-small { padding: 3px 9px; font-size: 0.85rem; }
.btn-icon { background: transparent; border: 1px solid var(--border); color: var(--muted); border-radius: 7px; padding: 6px 10px; cursor: pointer; }

.segmented { display: flex; flex-wrap: wrap; gap: 6px; }
.segmented label {
  flex: 1 1 auto;
  border: 1px solid var(--border); border-radius: 7px; padding: 7px 10px; cursor: pointer;
  display: flex; gap: 6px; align-items: center;
}
.segmented input { width: auto; }
.segmented label:has(input:checked) { border-color: var(--accent); background: var(--accent-soft); }

.tabs { display: flex; gap: 4px; border-bottom: 1px solid var(--border); margin-bottom: 12px; overflow-x: auto; }
.tabs button {
  background: none; border: 0; border-bottom: 2px solid transparent;
  padding: 8px 12px; cursor: pointer; color: var(--muted); white-space: nowrap;
}
.tabs button[aria-selected="true"] { color: var(--text); border-bottom-color: var(--accent); font-weight: 600; }

.hint { color: var(--muted); font-size: 0.88rem; margin: 6px 0; }

.map { height: 300px; border-radius: 8px; border: 1px solid var(--border); margin: 8px 0; z-index: 0; }

.bk50-result { margin-top: 10px; font-size: 0.88rem; }
.bk50-result table { border-collapse: collapse; width: 100%; }
.bk50-result td, .bk50-result th { border-bottom: 1px solid var(--border); padding: 3px 6px; text-align: left; vertical-align: top; }
.bk50-result .scroll { overflow-x: auto; max-height: 260px; overflow-y: auto; }
.code-buttons { display: flex; flex-wrap: wrap; gap: 6px; margin: 8px 0; }

.points { display: flex; flex-direction: column; gap: 8px; margin-top: 8px; }
.point { display: grid; grid-template-columns: minmax(0, 1fr) 92px minmax(0, 1fr) 96px auto; gap: 6px; align-items: center; }
@media (max-width: 520px) {
  .point { grid-template-columns: minmax(0, 1fr) 84px auto; }
  .point .water-value { grid-column: 1; }
  .point .water-unit { grid-column: 2; }
}

.status:empty { display: none; }
.status { padding: 8px 10px; border-radius: 7px; margin-bottom: 10px; background: var(--accent-soft); font-size: 0.9rem; }

.answers { display: grid; gap: 10px; grid-template-columns: repeat(auto-fit, minmax(220px, 1fr)); }
.answer { border: 1px solid var(--border); border-left: 4px solid var(--rosetta); border-radius: 8px; padding: 10px 12px; }
.answer.hypres { border-left-color: var(--hypres); }
.answer .label { font-size: 0.85rem; color: var(--muted); }
.answer .value { font-size: 1.7rem; font-weight: 700; line-height: 1.2; font-variant-numeric: tabular-nums; }
.answer .sub { font-size: 0.88rem; color: var(--muted); font-variant-numeric: tabular-nums; }
.msg { padding: 6px 9px; border-radius: 6px; font-size: 0.86rem; margin-top: 6px; }
.msg.warn { background: var(--warn-bg); color: var(--warn-text); }
.msg.error { background: var(--error-bg); color: var(--error-text); }

.chart { width: 100%; height: auto; margin-top: 12px; display: block; }
.chart .grid line { stroke: var(--grid); }
.chart .grid text { fill: var(--muted); font-size: 12px; }
.chart .axis-title { fill: var(--text); font-size: 13px; }
.chart .refs line { stroke: var(--muted); stroke-dasharray: 4 4; }
.chart .refs text { fill: var(--muted); font-size: 11px; }
.chart .curve { fill: none; stroke-width: 2.5; }
.chart .curve.rosetta { stroke: var(--rosetta); }
.chart .curve.hypres { stroke: var(--hypres); }
.chart .band { stroke: none; opacity: 0.18; }
.chart .band.rosetta { fill: var(--rosetta); }
.chart .measured { fill: var(--card); stroke: var(--measured); stroke-width: 2; }
.chart .marker line { stroke: var(--accent); stroke-dasharray: 3 3; }
.chart .marker circle { fill: var(--accent); }

.legend { display: flex; flex-wrap: wrap; gap: 14px; font-size: 0.85rem; color: var(--muted); margin-top: 4px; }
.legend i { display: inline-block; width: 18px; height: 3px; vertical-align: middle; margin-right: 5px; }

table.values { width: 100%; border-collapse: collapse; margin-top: 12px; font-size: 0.9rem; font-variant-numeric: tabular-nums; }
table.values th, table.values td { padding: 4px 6px; border-bottom: 1px solid var(--border); text-align: right; }
table.values th:first-child, table.values td:first-child { text-align: left; }
table.values thead th { color: var(--muted); font-weight: 600; }

.derived { font-size: 0.85rem; color: var(--muted); margin-top: 10px; }