.topbar.with-back {
  display: flex;
  align-items: baseline;
  gap: 16px;
  flex-wrap: wrap;
}
.topbar .back {
  color: var(--accent);
  text-decoration: none;
  font-size: 14px;
  margin-right: 8px;
}
.topbar .back:hover { color: var(--accent-hover); }

.status-bar {
  display: flex;
  align-items: center;
  gap: 10px;
  padding: 12px 48px;
  border-bottom: 1px solid var(--border);
  background: var(--panel);
  font-size: 13px;
}
.status-bar .spacer { flex: 1; }
.status-bar .muted { color: var(--muted); }

.dot {
  display: inline-block;
  width: 10px;
  height: 10px;
  border-radius: 50%;
  background: var(--muted);
  transition: background 0.2s ease;
}
.dot.live { background: #2ecc71; box-shadow: 0 0 8px #2ecc71; }
.dot.warn { background: #f0b429; }
.dot.fail { background: #e74c3c; }

.err-badge {
  background: rgba(231, 76, 60, 0.15);
  color: #ff7b6b;
  border: 1px solid rgba(231, 76, 60, 0.4);
  padding: 2px 8px;
  border-radius: 4px;
  font-size: 12px;
}
.hidden { display: none !important; }

.ph-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(360px, 1fr));
  gap: 20px;
  padding: 32px 48px;
  max-width: 1400px;
  margin: 0 auto;
}

.sensor-card {
  background: var(--panel);
  border: 1px solid var(--border);
  border-radius: 12px;
  padding: 20px;
  display: flex;
  flex-direction: column;
  gap: 18px;
  transition: border-color 0.2s ease;
}
.sensor-card.stale { border-color: rgba(240, 180, 41, 0.6); }
.sensor-card.error { border-color: rgba(231, 76, 60, 0.6); }

.sensor-head {
  display: flex;
  flex-direction: column;
  gap: 6px;
}
.sensor-title {
  display: flex;
  align-items: center;
  gap: 10px;
}
.sensor-title h2 {
  margin: 0;
  font-size: 18px;
  font-weight: 600;
}
.slave-pill {
  background: var(--panel-2);
  border: 1px solid var(--border);
  color: var(--accent);
  font-size: 11px;
  font-weight: 600;
  letter-spacing: 0.5px;
  padding: 3px 8px;
  border-radius: 4px;
}
.sensor-meta {
  display: flex;
  gap: 12px;
  font-size: 12px;
  color: var(--muted);
}
.sensor-meta .serial {
  font-family: ui-monospace, SFMono-Regular, Menlo, monospace;
}

.value-row {
  display: flex;
  align-items: flex-end;
  justify-content: space-between;
  gap: 16px;
}

.primary-value {
  display: flex;
  align-items: baseline;
  gap: 8px;
}
.primary-value .num {
  font-size: 48px;
  font-weight: 200;
  font-variant-numeric: tabular-nums;
  letter-spacing: -1px;
  color: var(--text);
}
.primary-value .unit {
  color: var(--muted);
  font-size: 16px;
  font-weight: 400;
}

.aux {
  display: flex;
  flex-direction: column;
  gap: 4px;
  text-align: right;
  font-variant-numeric: tabular-nums;
  font-size: 13px;
}
.aux .label {
  display: inline-block;
  min-width: 56px;
  color: var(--muted);
  margin-right: 8px;
}
.aux .unit {
  color: var(--muted);
  margin-left: 4px;
}

.sensor-foot {
  display: flex;
  justify-content: space-between;
  align-items: center;
  font-size: 12px;
  color: var(--muted);
  border-top: 1px solid var(--border);
  padding-top: 10px;
}
.stale-warn {
  color: #f0b429;
  font-weight: 600;
  letter-spacing: 0.5px;
}

.empty-card, .error-card {
  grid-column: 1 / -1;
  background: var(--panel);
  border: 1px solid var(--border);
  border-radius: 12px;
  padding: 32px;
  text-align: center;
}
.error-card { border-color: rgba(231, 76, 60, 0.4); }
.empty-card h2, .error-card h2 { margin-top: 0; }
.empty-card code, .error-card code {
  background: var(--panel-2);
  padding: 2px 6px;
  border-radius: 4px;
  font-size: 13px;
}

.page-foot {
  text-align: center;
  padding: 24px;
  color: var(--muted);
  font-size: 12px;
  border-top: 1px solid var(--border);
}
.page-foot code {
  background: var(--panel-2);
  padding: 1px 6px;
  border-radius: 3px;
}

.trend-section {
  display: flex;
  flex-direction: column;
  gap: 20px;
  padding: 0 48px 32px;
  max-width: 1400px;
  margin: 0 auto;
}

.trend-card {
  background: var(--panel);
  border: 1px solid var(--border);
  border-radius: 12px;
  padding: 16px 20px 12px;
}

.trend-head {
  display: flex;
  align-items: baseline;
  justify-content: space-between;
  gap: 16px;
  flex-wrap: wrap;
  margin-bottom: 8px;
}
.trend-title {
  display: flex;
  align-items: baseline;
  gap: 12px;
  flex-wrap: wrap;
}
.trend-title h3 {
  margin: 0;
  font-size: 15px;
  font-weight: 600;
  letter-spacing: 0.3px;
}

/* Primary-metric toggle (pH | mV) — segmented control matching .trend-ranges. */
.metric-toggle {
  display: inline-flex;
  gap: 2px;
  background: var(--panel-2);
  border: 1px solid var(--border);
  border-radius: 6px;
  padding: 2px;
}
.metric-btn {
  background: transparent;
  border: 0;
  color: var(--muted);
  padding: 3px 10px;
  font-size: 11px;
  font-weight: 600;
  letter-spacing: 0.3px;
  border-radius: 4px;
  cursor: pointer;
  font-variant-numeric: tabular-nums;
  transition: background 0.12s ease, color 0.12s ease;
}
.metric-btn:hover { color: var(--text); }
.metric-btn.active {
  background: var(--accent);
  color: #fff;
}
.trend-meta {
  font-size: 12px;
  color: var(--muted);
  font-variant-numeric: tabular-nums;
}

.trend-ranges {
  display: inline-flex;
  gap: 4px;
  background: var(--panel-2);
  border: 1px solid var(--border);
  border-radius: 6px;
  padding: 2px;
}
.range-btn {
  background: transparent;
  border: 0;
  color: var(--muted);
  padding: 4px 10px;
  font-size: 12px;
  font-weight: 500;
  border-radius: 4px;
  cursor: pointer;
  transition: background 0.12s ease, color 0.12s ease;
}
.range-btn:hover { color: var(--text); }
.range-btn.active {
  background: var(--accent);
  color: #fff;
}

/* Calendar/date picker — slot into the same .trend-ranges row as the buttons. */
.date-pick-wrap { display: inline-flex; position: relative; }
.calendar-btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  padding: 4px 8px;
}
.calendar-btn svg { display: block; }

/* Popup that opens below the calendar button. */
.cal-popup {
  position: absolute;
  top: calc(100% + 6px);
  right: 0;
  width: 240px;
  background: var(--panel);
  border: 1px solid var(--border);
  border-radius: 8px;
  padding: 12px;
  box-shadow: 0 6px 18px rgba(0, 0, 0, 0.45);
  z-index: 20;
}
.cal-popup.hidden { display: none; }

.cal-hdr {
  display: flex;
  align-items: center;
  justify-content: space-between;
  margin-bottom: 8px;
}
.cal-nav {
  background: transparent;
  border: 0;
  color: var(--text);
  font-size: 18px;
  line-height: 1;
  cursor: pointer;
  padding: 2px 8px;
  border-radius: 4px;
}
.cal-nav:hover { color: var(--accent); background: var(--panel-2); }
.cal-month-label {
  font-size: 13px;
  font-weight: 600;
  letter-spacing: 0.3px;
}

.cal-dow {
  display: grid;
  grid-template-columns: repeat(7, 1fr);
  gap: 2px;
  margin-bottom: 4px;
  font-size: 10px;
  color: var(--muted);
  text-align: center;
}

.cal-grid {
  display: grid;
  grid-template-columns: repeat(7, 1fr);
  gap: 2px;
}
.cal-cell {
  display: flex;
  align-items: center;
  justify-content: center;
  height: 28px;
  border: 0;
  padding: 0;
  background: transparent;
  color: var(--muted);
  font-size: 12px;
  font-variant-numeric: tabular-nums;
  border-radius: 4px;
  cursor: not-allowed;       /* default: no-data day */
}
/* Days from the previous/next month: heavily faded out */
.cal-cell.dim { opacity: 0.25; }

/* Days that have data — the affordance the user asked for. */
.cal-cell.has-data {
  background: rgba(46, 204, 113, 0.18);
  color: #2ecc71;
  font-weight: 600;
  cursor: pointer;
}
.cal-cell.has-data:hover {
  background: rgba(46, 204, 113, 0.32);
}

/* The currently-selected day (matches the active frozen view). */
.cal-cell.selected {
  background: var(--accent);
  color: #fff;
}
.cal-cell.selected:hover { background: var(--accent-hover, var(--accent)); }

/* Today gets a thin outline regardless of data presence. */
.cal-cell.today { box-shadow: inset 0 0 0 1px var(--accent); }

.frozen-pill {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  background: rgba(74, 144, 226, 0.18);
  border: 1px solid rgba(74, 144, 226, 0.6);
  color: #cfe1f7;
  font-size: 12px;
  font-weight: 500;
  padding: 4px 10px;
  border-radius: 999px;
  cursor: pointer;
  transition: background 0.12s ease;
}
.frozen-pill:hover { background: rgba(74, 144, 226, 0.28); }
.frozen-pill .x {
  font-size: 14px;
  line-height: 1;
  opacity: 0.75;
}
.frozen-pill.hidden { display: none; }

.trend-plot-wrap {
  position: relative;
  width: 100%;
}

.trend-svg {
  display: block;
  width: 100%;
  height: 280px;
}

.trend-svg .hover-target { cursor: default; }
.trend-svg .hover-target.clickable { cursor: crosshair; }

.trend-svg .preview-band {
  fill: rgba(74, 144, 226, 0.16);
  stroke: rgba(74, 144, 226, 0.55);
  stroke-width: 1;
  stroke-dasharray: 4 3;
  pointer-events: none;
}

.trend-svg .crosshair {
  stroke: rgba(255, 255, 255, 0.35);
  stroke-width: 1;
  stroke-dasharray: 3 3;
  pointer-events: none;
}

.trend-svg .marker {
  stroke: rgba(0, 0, 0, 0.85);
  stroke-width: 1.5;
  pointer-events: none;
}
.trend-svg .marker.primary-marker { fill: #2ecc71; }
.trend-svg .marker.temp-marker    { fill: #f0b429; }

.trend-svg .hidden { display: none; }

.trend-tooltip {
  position: absolute;
  pointer-events: none;
  background: rgba(20, 22, 28, 0.96);
  border: 1px solid var(--border);
  border-radius: 6px;
  padding: 8px 10px;
  font-size: 12px;
  font-family: ui-monospace, SFMono-Regular, Menlo, monospace;
  color: var(--text);
  line-height: 1.5;
  box-shadow: 0 4px 12px rgba(0, 0, 0, 0.4);
  white-space: nowrap;
  z-index: 5;
}
.trend-tooltip.hidden { display: none; }
.trend-tooltip .tt-time {
  color: var(--muted);
  font-size: 11px;
  margin-bottom: 4px;
  letter-spacing: 0.3px;
}
.trend-tooltip .tt-sn {
  color: var(--muted);
  font-size: 10px;
  letter-spacing: 0.4px;
  margin-bottom: 6px;
  padding-bottom: 4px;
  border-bottom: 1px solid var(--border);
}
.trend-tooltip .tt-time .agg-note {
  color: var(--accent);
  margin-left: 6px;
  font-style: italic;
}
.trend-tooltip .tt-row.primary { color: #2ecc71; font-weight: 600; }
.trend-tooltip .tt-row { color: var(--text); }

.trend-svg .grid {
  stroke: var(--border);
  stroke-width: 1;
  stroke-dasharray: 2 3;
  opacity: 0.5;
}
.trend-svg .plot-border {
  fill: none;
  stroke: var(--border);
  stroke-width: 1;
}
.trend-svg .tick-label {
  fill: var(--muted);
  font-size: 11px;
  font-family: ui-monospace, SFMono-Regular, Menlo, monospace;
}
.trend-svg .axis-label {
  fill: var(--muted);
  font-size: 11px;
  font-weight: 600;
  letter-spacing: 0.5px;
}
.trend-svg .primary-label { fill: #2ecc71; }
.trend-svg .temp-label { fill: #f0b429; }

.trend-svg .primary-line {
  fill: none;
  stroke: #2ecc71;
  stroke-width: 1.6;
  stroke-linejoin: round;
  stroke-linecap: round;
}
.trend-svg .primary-band {
  fill: rgba(46, 204, 113, 0.18);
  stroke: none;
}
.trend-svg .temp-line {
  fill: none;
  stroke: #f0b429;
  stroke-width: 1.2;
  stroke-linejoin: round;
  stroke-linecap: round;
  stroke-dasharray: 4 3;
  opacity: 0.85;
}

.trend-svg .trend-empty,
.trend-svg .trend-err {
  fill: var(--muted);
  font-size: 13px;
}
.trend-svg .trend-err { fill: #ff7b6b; }

.trend-legend {
  display: flex;
  gap: 18px;
  font-size: 12px;
  color: var(--muted);
  margin-top: 8px;
  padding-left: 4px;
}
.legend-item {
  display: inline-flex;
  align-items: center;
  gap: 6px;
}
.legend-item .swatch {
  display: inline-block;
  width: 14px;
  height: 3px;
  border-radius: 2px;
}
.legend-item.primary .swatch { background: #2ecc71; }
.legend-item.temp .swatch { background: #f0b429; }