:root {
  --bg: #eef0f4;
  --card-bg: #ffffff;
  --card-border: #e1e4ea;
  --text: #1a1a2e;
  --muted: #6b7280;
  --accent: #4a90d9;
  --accent-dark: #2a70b9;
  --gold: #FFD700;
  --orange: #ff7a00;
  --panel-bg: #0d0d1a;
  --panel-bg-2: #14142b;
  --radius: 12px;
  --shadow: 0 1px 3px rgba(20, 20, 40, 0.08), 0 1px 2px rgba(20, 20, 40, 0.06);
  --shadow-hover: 0 4px 14px rgba(20, 20, 40, 0.12), 0 2px 4px rgba(20, 20, 40, 0.08);
}

* { box-sizing: border-box; }

html, body {
  margin: 0;
  padding: 0;
  background: var(--bg);
  color: var(--text);
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, Helvetica, Arial, sans-serif;
}

.app-header {
  position: relative;
  text-align: center;
  padding: 28px 16px 8px;
}

.app-header h1 {
  margin: 0;
  font-size: 28px;
  font-weight: 700;
  letter-spacing: -0.02em;
}

.app-header .accent { color: var(--accent); }

.app-header .subtitle {
  margin: 4px 0 0;
  color: var(--muted);
  font-size: 14px;
}

main.layout {
  max-width: 1320px;
  margin: 0 auto;
  padding: 16px 20px 60px;
  display: grid;
  grid-template-columns: minmax(0, 1fr) 340px;
  gap: 18px;
  align-items: start;
}

/* ---------------- Settings button (anchored to the header, scrolls with the page) ---------------- */

.header-actions {
  position: absolute;
  top: 16px;
  right: 18px;
  z-index: 5;
  display: flex;
  gap: 8px;
}

.settings-fab {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  border: 1px solid var(--accent);
  background: #f0f6fd;
  color: var(--accent-dark);
  font-weight: 600;
  font-size: 12.5px;
  padding: 7px 13px;
  border-radius: 999px;
  cursor: pointer;
  box-shadow: var(--shadow);
  transition: background 0.15s ease, color 0.15s ease, box-shadow 0.15s ease;
}

.settings-fab:hover {
  background: var(--accent);
  color: white;
  box-shadow: var(--shadow-hover);
}

/* ---------------- Exposure heatmap toggle bar ---------------- */

.exposure-toggle-bar {
  grid-column: 1 / -1;
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 12px;
  background: var(--card-bg);
  border: 1px solid var(--card-border);
  border-radius: var(--radius);
  padding: 10px 16px;
}

.exposure-checkbox-label {
  display: inline-flex;
  align-items: center;
  gap: 7px;
  font-size: 13px;
  font-weight: 600;
  color: var(--text);
  cursor: pointer;
}

.exposure-checkbox-label input[type="checkbox"] {
  width: 15px;
  height: 15px;
  cursor: pointer;
}

.exposure-checkbox-label input[type="checkbox"]:disabled {
  cursor: not-allowed;
}

#exposure-toggle-status {
  flex: 1 1 auto;
}

.exposure-setup-btn {
  flex: 0 0 auto;
  border: 1px solid var(--accent);
  background: #f0f6fd;
  color: var(--accent-dark);
  font-weight: 600;
  font-size: 12px;
  padding: 7px 13px;
  border-radius: 999px;
  cursor: pointer;
  transition: background 0.15s ease, color 0.15s ease;
}

.exposure-setup-btn:hover {
  background: var(--accent);
  color: white;
}

/* ---------------- Panels ---------------- */

.panels {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 12px;
  align-content: start;
}

.panel {
  background: var(--card-bg);
  border: 1px solid var(--card-border);
  border-radius: var(--radius);
  box-shadow: var(--shadow);
  padding: 8px 10px 6px;
  display: flex;
  flex-direction: column;
  transition: box-shadow 0.18s ease, transform 0.18s ease;
}

.panel:hover {
  box-shadow: var(--shadow-hover);
  transform: translateY(-1px);
}

.panel-header {
  display: flex;
  align-items: baseline;
  justify-content: space-between;
  margin-bottom: 6px;
}

.panel-title {
  font-size: 13px;
  font-weight: 600;
  color: var(--text);
}

.panel-pct {
  font-size: 12px;
  font-weight: 700;
  color: #b8860b;
  font-variant-numeric: tabular-nums;
  transition: color 0.25s ease;
}

.panel-canvas-wrap {
  position: relative;
  width: 100%;
  border-radius: 6px;
  overflow: hidden;
  background: var(--panel-bg);
}

.panel-canvas-wrap canvas {
  display: block;
  width: 100%;
  height: 100%;
}

/* East wall's data is laid out S->N left-to-right (same convention as the
   floor/north/west panels' shared axes), but viewing the east wall from
   inside the room facing east puts north on your left -- the opposite of
   north/west's "facing the wall" convention. Mirroring just the display
   (not the underlying data) makes all three side walls visually consistent
   without touching any physics/rendering math. */
#canvas-east {
  transform: scaleX(-1);
}

.panel[data-surface="floor"] .panel-canvas-wrap,
.panel[data-surface="north"] .panel-canvas-wrap,
.panel[data-surface="east"] .panel-canvas-wrap,
.panel[data-surface="west"] .panel-canvas-wrap {
  aspect-ratio: 4 / 3;
}

.panel-south .panel-canvas-wrap {
  aspect-ratio: 4 / 3;
  background: #2c2c3e;
}

.panel-axis {
  margin-top: 6px;
  font-size: 10.5px;
  color: var(--muted);
  text-align: center;
}

/* ---------------- Info panel ---------------- */

.info-panel {
  background: var(--card-bg);
  border: 1px solid var(--card-border);
  border-radius: var(--radius);
  box-shadow: var(--shadow);
  padding: 16px 18px;
  display: flex;
  flex-direction: column;
  gap: 14px;
}

.info-item {
  display: flex;
  flex-direction: column;
  gap: 2px;
}

.info-label {
  font-size: 11px;
  text-transform: uppercase;
  letter-spacing: 0.04em;
  color: var(--muted);
}

.info-value {
  font-family: "SFMono-Regular", Consolas, "Liberation Mono", Menlo, monospace;
  font-size: 15px;
  font-weight: 600;
  transition: color 0.25s ease;
}

.info-value.flash { color: var(--accent-dark); }

.presets {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 8px;
  margin-top: 14px;
}

.presets-label {
  font-size: 12px;
  color: var(--muted);
  margin-right: 2px;
  width: 100%;
}

.preset-btn,
.exposure-preset-btn {
  border: 1px solid var(--card-border);
  background: #f6f7fb;
  color: var(--text);
  padding: 6px 12px;
  font-size: 12.5px;
  font-weight: 600;
  border-radius: 8px;
  cursor: pointer;
  transition: background 0.15s ease, border-color 0.15s ease;
}

.preset-btn:hover,
.exposure-preset-btn:hover {
  background: var(--accent);
  border-color: var(--accent);
  color: white;
}

.animate-btn {
  width: 100%;
  margin-top: 14px;
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 8px;
  border: none;
  background: var(--accent);
  color: white;
  font-weight: 700;
  font-size: 13px;
  padding: 10px 16px;
  border-radius: 8px;
  cursor: pointer;
  transition: background 0.15s ease;
}

.animate-btn:hover { background: var(--accent-dark); }

.animate-btn.playing {
  background: #d9534f;
}

.animate-btn.playing:hover { background: #c9302c; }

.animate-icon {
  font-size: 12px;
  line-height: 1;
}

/* ---------------- Settings modal ---------------- */

.modal-overlay {
  position: fixed;
  inset: 0;
  z-index: 1000;
  display: flex;
  align-items: center;
  justify-content: center;
  padding: 24px;
  background: rgba(20, 20, 40, 0.45);
  opacity: 0;
  visibility: hidden;
  transition: opacity 0.18s ease, visibility 0.18s ease;
}

.modal-overlay.open {
  opacity: 1;
  visibility: visible;
}

.modal {
  background: var(--card-bg);
  border-radius: var(--radius);
  box-shadow: 0 16px 48px rgba(20, 20, 40, 0.3);
  width: 100%;
  max-width: 920px;
  max-height: 88vh;
  display: flex;
  flex-direction: column;
  overflow: hidden;
  transform: translateY(10px) scale(0.98);
  transition: transform 0.18s ease;
}

.modal-overlay.open .modal {
  transform: translateY(0) scale(1);
}

/* ---------------- 3D view ---------------- */

.view3d-trigger-wrap {
  display: flex;
  justify-content: center;
  margin: 0 0 16px;
}

.view3d-trigger-btn {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  border: 1px solid var(--card-border);
  background: white;
  color: var(--text);
  font-weight: 600;
  font-size: 13px;
  padding: 9px 18px;
  border-radius: 999px;
  cursor: pointer;
  box-shadow: var(--shadow);
  transition: background 0.15s ease, border-color 0.15s ease, box-shadow 0.15s ease;
}

.view3d-trigger-btn:hover {
  background: #f0f6fd;
  border-color: var(--accent);
  box-shadow: var(--shadow-hover);
}

.modal-3d {
  max-width: 1200px;
  width: 95vw;
  height: 88vh;
}

/* ---------------- Year overview modal ---------------- */

.modal-year {
  max-width: 880px;
  width: 95vw;
}

.year-controls {
  display: flex;
  align-items: center;
  gap: 10px;
  margin-bottom: 12px;
}

.year-controls label {
  font-size: 12.5px;
  font-weight: 600;
  color: var(--text);
}

.year-controls select.select {
  width: auto;
  flex: 1;
  max-width: 280px;
}

.year-time-controls {
  flex-wrap: wrap;
}

.year-checkbox-label {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  cursor: pointer;
  font-weight: 500 !important;
}

.year-checkbox-label input[type="checkbox"] {
  width: 15px;
  height: 15px;
  cursor: pointer;
}

#year-time-row {
  margin: 0;
  opacity: 1;
  transition: opacity 0.15s ease;
}

#year-time-row.disabled {
  opacity: 0.4;
}

.animate-btn-compact {
  width: auto;
  margin-top: 0;
  margin-left: auto;
  padding: 7px 12px;
  font-size: 12px;
  border-radius: 999px;
  flex: 0 0 auto;
}

#year-scale-note {
  display: block;
  margin-bottom: 14px;
}

.year-grid {
  display: flex;
  flex-direction: column;
  gap: 3px;
  overflow-x: auto;
  padding-bottom: 4px;
}

.year-row {
  display: flex;
  align-items: center;
  gap: 3px;
}

.year-month-label {
  width: 34px;
  flex: 0 0 34px;
  font-size: 11px;
  font-weight: 600;
  color: var(--muted);
  text-align: right;
  padding-right: 4px;
}

.year-cell {
  width: 16px;
  height: 16px;
  flex: 0 0 16px;
  border-radius: 3px;
  cursor: default;
}

.year-cell.year-cell-marker {
  box-shadow: 0 0 0 1.5px #ffffff, 0 0 0 2.5px var(--accent);
}

.year-cell-empty {
  width: 16px;
  height: 16px;
  flex: 0 0 16px;
}

/* ---------------- How to use modal ---------------- */

.modal-help {
  max-width: 720px;
  width: 95vw;
}

.help-group {
  border: 1px solid var(--card-border);
  border-radius: 8px;
  margin-bottom: 10px;
  padding: 0 14px;
  background: #fafbfc;
}

.help-group:last-child { margin-bottom: 0; }

.help-group summary {
  padding: 11px 0;
  font-size: 13px;
  font-weight: 700;
  color: var(--accent-dark);
  cursor: pointer;
  list-style: none;
}

.help-group summary::-webkit-details-marker { display: none; }

.help-group summary::before {
  content: "▸";
  display: inline-block;
  margin-right: 8px;
  transition: transform 0.15s ease;
}

.help-group[open] summary::before {
  transform: rotate(90deg);
}

.help-item {
  font-size: 12.5px;
  line-height: 1.5;
  color: var(--text);
  padding: 8px 0;
  border-top: 1px solid var(--card-border);
}

.help-item strong {
  color: var(--accent-dark);
}

.scene3d-canvas-wrap {
  position: relative;
  flex: 1;
  min-height: 0;
  background: #14142b;
}

.scene3d-canvas-wrap canvas {
  display: block;
  width: 100%;
  height: 100%;
}

.scene3d-hint {
  padding: 10px 22px;
  font-size: 12px;
  color: var(--muted);
  text-align: center;
  border-top: 1px solid var(--card-border);
  background: #fafbfc;
}

.modal-header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 16px 22px;
  border-bottom: 1px solid var(--card-border);
}

.modal-header h2 {
  margin: 0;
  font-size: 16px;
  font-weight: 700;
}

.modal-close {
  border: none;
  background: none;
  font-size: 22px;
  line-height: 1;
  color: var(--muted);
  cursor: pointer;
  padding: 2px 9px;
  border-radius: 6px;
}

.modal-close:hover { background: #f0f1f5; color: var(--text); }

.modal-body {
  padding: 20px 22px;
  overflow-y: auto;
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 22px;
}

.modal-footer {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 14px 22px;
  border-top: 1px solid var(--card-border);
  background: #fafbfc;
}

.secondary-btn {
  border: 1px solid var(--card-border);
  background: white;
  color: var(--text);
  font-weight: 600;
  font-size: 13px;
  padding: 8px 14px;
  border-radius: 8px;
  cursor: pointer;
  transition: background 0.15s ease;
}

.secondary-btn:hover { background: #f6f7fb; }

.primary-btn {
  border: none;
  background: var(--accent);
  color: white;
  font-weight: 600;
  font-size: 13px;
  padding: 9px 20px;
  border-radius: 8px;
  cursor: pointer;
  transition: background 0.15s ease;
}

.primary-btn:hover { background: var(--accent-dark); }

.primary-btn:disabled,
.secondary-btn:disabled {
  opacity: 0.5;
  cursor: not-allowed;
}

/* ---------------- CSV report modal ---------------- */

.modal-body-block {
  display: block;
}

.report-hint {
  margin: 0 0 16px;
  font-size: 12.5px;
  color: var(--muted);
  line-height: 1.5;
}

.report-grid {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: 14px;
}

.report-grid .field { margin-bottom: 0; }

select.select {
  width: 100%;
  border: 1px solid var(--card-border);
  border-radius: 6px;
  padding: 6px;
  font-size: 12.5px;
  color: var(--text);
  background: #fafbfc;
}

select.select:focus {
  outline: none;
  border-color: var(--accent);
  box-shadow: 0 0 0 3px rgba(74, 144, 217, 0.15);
}

.report-progress-wrap {
  margin-top: 18px;
}

progress#report-progress,
progress#exposure-progress {
  width: 100%;
  height: 10px;
  border-radius: 6px;
  overflow: hidden;
  border: none;
  accent-color: var(--accent);
}

progress#report-progress::-webkit-progress-bar,
progress#exposure-progress::-webkit-progress-bar {
  background: #e1e4ea;
  border-radius: 6px;
}

progress#report-progress::-webkit-progress-value,
progress#exposure-progress::-webkit-progress-value {
  background: var(--accent);
  border-radius: 6px;
}

.report-status {
  margin-top: 10px;
  font-size: 12.5px;
  color: var(--muted);
  font-family: "SFMono-Regular", Consolas, "Liberation Mono", Menlo, monospace;
  min-height: 18px;
}

.report-trigger-btn {
  width: 100%;
  border: 1px solid var(--card-border);
  background: white;
  color: var(--text);
  font-weight: 600;
  font-size: 13px;
  padding: 10px 16px;
  border-radius: 8px;
  cursor: pointer;
  box-shadow: var(--shadow);
  transition: background 0.15s ease, border-color 0.15s ease;
}

.report-trigger-btn:hover {
  background: #f0f6fd;
  border-color: var(--accent);
}

#btn-optimize-length {
  margin-top: 4px;
}

#optimizer-status {
  margin-top: 8px;
}

#optimizer-status.error {
  color: #c9302c;
  font-style: normal;
  font-weight: 600;
}

#optimizer-status.success {
  color: var(--accent-dark);
  font-style: normal;
  font-weight: 600;
}

/* ---------------- Save / Share modal ---------------- */

.share-section {
  margin-bottom: 24px;
}
.share-section:last-child { margin-bottom: 0; }

.share-section h3 {
  margin: 0 0 4px;
  font-size: 13px;
  font-weight: 700;
  color: var(--text);
}

.share-link-row,
.preset-save-row {
  display: flex;
  gap: 8px;
  margin-top: 10px;
}

.share-link-row input,
.preset-save-row input {
  flex: 1;
  min-width: 0;
  border: 1px solid var(--card-border);
  border-radius: 6px;
  padding: 8px 10px;
  font-size: 12.5px;
  color: var(--text);
  background: #fafbfc;
  font-family: "SFMono-Regular", Consolas, "Liberation Mono", Menlo, monospace;
}

.preset-save-row input { font-family: inherit; }

.share-link-row input:focus,
.preset-save-row input:focus {
  outline: none;
  border-color: var(--accent);
  box-shadow: 0 0 0 3px rgba(74, 144, 217, 0.15);
}

#share-link-status,
#preset-save-status {
  margin-top: 8px;
  min-height: 16px;
}
#share-link-status.success,
#preset-save-status.success {
  color: var(--accent-dark);
  font-style: normal;
  font-weight: 600;
}

.preset-list {
  list-style: none;
  margin: 14px 0 0;
  padding: 0;
  display: flex;
  flex-direction: column;
  gap: 6px;
}

.preset-list li {
  display: flex;
  align-items: center;
  gap: 8px;
  padding: 8px 10px;
  border: 1px solid var(--card-border);
  border-radius: 8px;
  background: #fafbfc;
}

.preset-list .preset-name {
  flex: 1;
  min-width: 0;
  font-size: 13px;
  font-weight: 600;
  overflow: hidden;
  text-overflow: ellipsis;
  white-space: nowrap;
}

.preset-list .preset-empty {
  color: var(--muted);
  font-size: 12.5px;
  font-style: italic;
  border: none;
  background: none;
  padding: 4px 0;
}

.preset-list button {
  border: 1px solid var(--card-border);
  background: white;
  color: var(--text);
  font-weight: 600;
  font-size: 12px;
  padding: 5px 10px;
  border-radius: 6px;
  cursor: pointer;
  transition: background 0.15s ease;
}

.preset-list button:hover { background: #f6f7fb; }

.preset-list button.preset-delete:hover {
  background: #fdeceb;
  border-color: #c9302c;
  color: #c9302c;
}

/* ---------------- Sidebar (Shade / Date-Time / actions / info) ---------------- */

.sidebar {
  display: flex;
  flex-direction: column;
  gap: 16px;
}

.sidebar .control-group-wide {
  background: var(--card-bg);
  border: 1px solid var(--card-border);
  border-radius: var(--radius);
  box-shadow: var(--shadow);
  padding: 18px 20px;
}

.control-group-wide .field {
  margin-bottom: 18px;
}
.control-group-wide .field:last-child {
  margin-bottom: 0;
}

.control-group-wide .field-inputs {
  grid-template-columns: 1fr 76px;
}

.control-group h2 {
  font-size: 12px;
  font-weight: 700;
  text-transform: uppercase;
  letter-spacing: 0.05em;
  color: var(--accent-dark);
  margin: 0 0 10px;
  padding-bottom: 6px;
  border-bottom: 2px solid var(--accent);
}

.control-group h2 .unit {
  color: var(--muted);
  font-weight: 500;
  text-transform: none;
  letter-spacing: normal;
}

.field { margin-bottom: 12px; }
.field:last-child { margin-bottom: 0; }

.field label {
  display: block;
  font-size: 12px;
  color: var(--text);
  margin-bottom: 4px;
}

.field label .unit {
  color: var(--muted);
  font-size: 11px;
}

.field-note {
  margin: -4px 0 0;
  font-size: 11px;
  color: var(--muted);
  font-style: italic;
}

.field-inputs {
  display: grid;
  grid-template-columns: 1fr 64px;
  gap: 8px;
  align-items: center;
}

.field-inputs-single {
  grid-template-columns: 1fr;
  gap: 6px;
}

input[type="number"].number,
input[type="date"].date-input {
  width: 100%;
  border: 1px solid var(--card-border);
  border-radius: 6px;
  padding: 5px 6px;
  font-size: 12.5px;
  color: var(--text);
  background: #fafbfc;
  font-variant-numeric: tabular-nums;
}

input[type="number"].number:focus,
input[type="date"].date-input:focus {
  outline: none;
  border-color: var(--accent);
  box-shadow: 0 0 0 3px rgba(74, 144, 217, 0.15);
}

/* Custom 24-hour HH:MM input -- two number fields, since the native
   <input type="time"> picker's AM/PM vs 24h display is locale-dependent
   and not reliably controllable from the page. */
.time24 {
  display: flex;
  align-items: center;
  gap: 4px;
}

.time24-part {
  width: 100%;
  min-width: 0;
  border: 1px solid var(--card-border);
  border-radius: 6px;
  padding: 5px 4px;
  font-size: 12.5px;
  text-align: center;
  color: var(--text);
  background: #fafbfc;
  font-variant-numeric: tabular-nums;
}

.time24-part:focus {
  outline: none;
  border-color: var(--accent);
  box-shadow: 0 0 0 3px rgba(74, 144, 217, 0.15);
}

.time24-sep {
  font-weight: 700;
  color: var(--muted);
}

input[type="range"].slider {
  -webkit-appearance: none;
  appearance: none;
  width: 100%;
  height: 18px;
  background: transparent;
  cursor: pointer;
}

input[type="range"].slider::-webkit-slider-runnable-track {
  height: 4px;
  border-radius: 2px;
  background: linear-gradient(to right, var(--accent) 0%, var(--accent) var(--fill, 50%), #e1e4ea var(--fill, 50%), #e1e4ea 100%);
}

input[type="range"].slider::-webkit-slider-thumb {
  -webkit-appearance: none;
  width: 16px;
  height: 16px;
  margin-top: -6px;
  border-radius: 50%;
  background: var(--accent);
  border: 2px solid white;
  box-shadow: 0 1px 3px rgba(0,0,0,0.3);
  transition: transform 0.1s ease;
}

input[type="range"].slider::-webkit-slider-thumb:hover { transform: scale(1.15); }

input[type="range"].slider::-moz-range-track {
  height: 4px;
  border-radius: 2px;
  background: #e1e4ea;
}

input[type="range"].slider::-moz-range-progress {
  height: 4px;
  border-radius: 2px;
  background: var(--accent);
}

input[type="range"].slider::-moz-range-thumb {
  width: 14px;
  height: 14px;
  border-radius: 50%;
  background: var(--accent);
  border: 2px solid white;
  box-shadow: 0 1px 3px rgba(0,0,0,0.3);
}

.control-actions {
  display: flex;
  justify-content: center;
}

#btn-reset-play {
  width: 100%;
  border: none;
  background: var(--accent);
  color: white;
  font-weight: 600;
  font-size: 13px;
  padding: 10px 18px;
  border-radius: 8px;
  cursor: pointer;
  transition: background 0.15s ease;
}

#btn-reset-play:hover { background: var(--accent-dark); }

/* ---------------- Footer ---------------- */

.app-footer {
  text-align: center;
  padding: 10px 20px;
  font-size: 11px;
  color: var(--muted);
  border-top: 1px solid var(--card-border);
}

.app-footer a { color: var(--muted); text-decoration: none; }
.app-footer a:hover { color: var(--text); }
.app-footer-sep { margin: 0 6px; }

/* ---------------- Responsive ---------------- */

@media (max-width: 1100px) {
  main.layout { grid-template-columns: minmax(0, 1fr) 300px; }
}

@media (max-width: 900px) {
  main.layout { grid-template-columns: 1fr; }
  .panels { grid-template-columns: repeat(3, 1fr); }
  .modal-body { grid-template-columns: repeat(2, 1fr); }
}

@media (max-width: 700px) {
  .panels { grid-template-columns: repeat(2, 1fr); }
  .modal-body { grid-template-columns: 1fr; }
  .report-grid { grid-template-columns: 1fr; }
}

@media (max-width: 480px) {
  .panels { grid-template-columns: 1fr; }
}