:root {
  --background: #FFFCF0;
  --text: #242824;
  --fire: #D91816;
  --earth: #749020;
  --water: #0079C7;
  --air: #DDA801;
  --boundary: #575B53;
  --muted: #62675E;
  --line: #D6D7CF;
  --field: #FCFAF6;
  --backing: #FFFCF0;
  --control-border: #BFC3B8;
  --control-hover: #E8E8DF;
  --placeholder: #73786D;
  --accent: #697760;
  --action-hover: #3B4338;
  color-scheme: light;
  font-family: Arial, Helvetica, sans-serif;
  color: var(--text);
  background: var(--background);
  font-synthesis: none;
}
/* Paired palettes match the two supplied symbol sheets exactly. */
:root[data-theme="dark"] {
  --fire: #D36341;
  --earth: #8BA74B;
  --water: #439C96;
  --air: #E9DF6F;
  --background: #262626;
  --text: #EEECE6;
  --muted: #B7BCB8;
  --line: #42474A;
  --field: #2D3032;
  --backing: #262626;
  --boundary: #A4ABA6;
  --control-border: #738083;
  --control-hover: #3F4645;
  --placeholder: #A4ABA6;
  --accent: #AABBA0;
  --action-hover: #D1D6CC;
  color-scheme: dark;
}
* { box-sizing: border-box; }
body { margin: 0; }
button, input { font: inherit; color: inherit; }
button { cursor: pointer; touch-action: manipulation; }
button:disabled { cursor: default; opacity: .38; }
button:focus-visible, input:focus-visible { outline: 2px solid var(--text); outline-offset: 4px; }
p, h1, h2 { margin: 0; }
.app { width: 100%; min-height: 100dvh; padding: 24px 36px 28px; }
.workspace-header { display: flex; flex-wrap: wrap; justify-content: space-between; align-items: center; gap: 20px; padding-bottom: 22px; border-bottom: 1px solid var(--line); }
.header-actions { display: flex; align-items: center; gap: 22px; margin-left: auto; }
.theme-toggle { display: inline-flex; align-items: center; gap: 9px; position: relative; min-height: 36px; font-size: 14px; cursor: pointer; white-space: nowrap; }
.theme-toggle input { position: absolute; width: 1px; height: 1px; opacity: 0; }
.switch-track { position: relative; width: 34px; height: 20px; border-radius: 12px; border: 1px solid var(--control-border); background: var(--field); }
.switch-track::after { content: ''; position: absolute; top: 3px; left: 3px; width: 12px; height: 12px; border-radius: 50%; background: var(--muted); }
.theme-toggle input:checked + .switch-track { background: var(--accent); border-color: var(--accent); }
.theme-toggle input:checked + .switch-track::after { transform: translateX(14px); background: var(--background); }
.theme-toggle input:focus-visible + .switch-track { outline: 2px solid var(--text); outline-offset: 4px; }
.workspace-title { display: flex; align-items: center; gap: 24px; }
.brand { font-family: Georgia, 'Times New Roman', serif; font-size: 32px; letter-spacing: -1.6px; }
h1 { font-size: 20px; font-weight: 400; letter-spacing: -.35px; padding-left: 24px; border-left: 1px solid var(--control-border); }
.prototype { font-size: 12px; letter-spacing: 1px; color: var(--muted); }
.workspace { display: grid; grid-template-columns: minmax(0, 1fr) 336px; align-items: start; gap: 40px; padding-top: 24px; }
.canvas { min-width: 0; }
.mosaic-meta { display: flex; justify-content: space-between; align-items: center; gap: 16px; margin-bottom: 17px; }
.mosaic-meta h2 { font-size: 16px; font-weight: 500; }
#activity-count { font-size: 14px; color: var(--muted); }
.preview-toolbar { display: flex; align-items: center; gap: 12px; margin-bottom: 22px; color: var(--muted); font-size: 13px; }
.preview-toolbar input { width: 150px; min-width: 50px; }
.preview-toolbar output { min-width: 47px; font-variant-numeric: tabular-nums; }
.preview-toolbar button { background: none; border: 1px solid var(--control-border); border-radius: 4px; padding: 6px 12px; font-size: 13px; }
.mosaic-stage { display: flex; justify-content: center; align-items: center; width: 100%; min-height: min(700px, max(460px, calc(100dvh - 305px))); }
.mosaic-frame { position: relative; width: min(100%, var(--preview-width, 760px)); aspect-ratio: 1; flex-shrink: 0; border: 0; border-radius: 5px; overflow: visible; background: var(--backing); }
#mosaic { display: block; width: 100%; height: 100%; overflow: visible; touch-action: pan-y pinch-zoom; user-select: none; -webkit-user-select: none; }
.piece { cursor: pointer; outline: none; }
.tile-hit { pointer-events: all; }
.tile-visual { pointer-events: none; }
.selection-mark, .focus-ring, .press-sheen { opacity: 0; pointer-events: none; }
.piece.is-selected .selection-mark { opacity: .65; }
.piece:focus-visible .focus-ring { opacity: .8; }
.piece.is-pressed .press-sheen { opacity: .025; }
.piece:hover:not(.is-pressed) .press-sheen { opacity: .018; }
.empty { position: absolute; inset: 0; display: flex; flex-direction: column; justify-content: center; align-items: center; text-align: center; pointer-events: none; }
.empty[hidden] { display: none; }
.empty h2 { font: 400 28px Georgia, serif; margin-bottom: 12px; }
.empty p { font-size: 16px; line-height: 1.65; color: var(--muted); }
.detail { display: flex; align-items: center; gap: 12px; min-height: 72px; padding: 17px 0 10px; }
.detail-marker { width: 12px; height: 12px; border: 1px solid var(--boundary); border-radius: 50%; flex-shrink: 0; background: var(--background); }
.detail > div { min-width: 0; flex: 1; }
#detail-name { font-size: 16px; font-weight: 500; overflow-wrap: anywhere; }
#detail-element { font-size: 14px; color: var(--muted); margin-top: 5px; line-height: 1.4; }
.close-button { border: 1px solid var(--control-border); border-radius: 4px; padding: 7px 10px; background: transparent; font-size: 13px; }
.mosaic-hint { font-size: 13px; line-height: 1.6; color: var(--muted); }
.control-panel { min-width: 0; padding-left: 28px; border-left: 1px solid var(--line); }
.control-panel h2 { font-size: 16px; font-weight: 500; }
.add-section h2 { margin-bottom: 16px; }
form > label, legend { font-size: 14px; }
#activity-name { width: 100%; background: var(--field); border: 1px solid var(--control-border); border-radius: 4px; padding: 12px; margin-top: 9px; font-size: 16px; line-height: 1.4; }
input::placeholder { font-size: 14px; color: var(--placeholder); }
fieldset { padding: 0; margin: 14px 0; border: 0; }
legend { margin-bottom: 9px; padding: 0; }
.element-options { display: grid; grid-template-columns: repeat(4, 1fr); gap: 6px; }
.element-options label { position: relative; cursor: pointer; }
.element-options input { position: absolute; opacity: 0; inset: 0; width: 100%; height: 100%; margin: 0; cursor: pointer; }
.element-options label > span { display: flex; gap: 6px; align-items: center; justify-content: center; min-height: 42px; border: 1px solid var(--control-border); border-radius: 4px; font-size: 14px; }
.element-options input:checked + span { border-color: var(--text); box-shadow: inset 0 0 0 .5px var(--text); background: var(--control-hover); }
.element-options input:focus-visible + span { outline: 2px solid var(--text); outline-offset: 3px; }
.swatch { display: inline-block; width: 12px; height: 12px; flex-shrink: 0; border: 1px solid var(--boundary); border-radius: 2px; }
.element-options .swatch { width: 10px; height: 10px; }
.fire { background: var(--fire); }
.earth { background: var(--earth); }
.water { background: var(--water); }
.air { background: var(--air); }
.add-button { display: flex; align-items: center; justify-content: center; gap: 9px; width: 100%; background: var(--text); color: var(--background); border: 1px solid var(--text); border-radius: 4px; padding: 11px 12px; min-height: 44px; font-size: 14px; }
.add-button span { font-size: 19px; line-height: 1; }
.add-button:hover { background: var(--action-hover); }
.undo-row { display: flex; gap: 13px; align-items: center; margin-top: 14px; }
.quiet-button { display: flex; align-items: center; gap: 7px; border: 1px solid var(--control-border); border-radius: 4px; background: none; padding: 9px 11px; font-size: 14px; min-height: 40px; }
.quiet-button span { font-size: 21px; line-height: 1; }
.quiet-button:enabled:hover, .demo-buttons button:hover { background: var(--control-hover); }
.undo-row > span { font-size: 12px; color: var(--muted); line-height: 1.5; }
.demo-section, .elements, .visual-settings { border-top: 1px solid var(--line); margin-top: 20px; padding-top: 18px; }
.demo-heading { display: flex; align-items: baseline; justify-content: space-between; gap: 12px; }
.demo-heading > span { font-size: 12px; letter-spacing: .6px; color: var(--muted); }
.demo-buttons { display: grid; grid-template-columns: repeat(4, 1fr); gap: 7px; margin-top: 14px; }
.demo-buttons button { background: none; border: 1px solid var(--control-border); border-radius: 4px; min-height: 40px; padding: 6px 3px; font-size: 14px; }
.demo-section p { font-size: 12px; color: var(--muted); margin-top: 11px; line-height: 1.5; }
.legend { list-style: none; display: grid; gap: 10px; margin: 15px 0 0; padding: 0; }
.legend li { display: flex; align-items: flex-start; gap: 10px; }
.legend .swatch { margin-top: 3px; }
.legend strong { font-size: 14px; font-weight: 500; }
.legend div { display: grid; grid-template-columns: 42px 1fr; gap: 8px; }
.legend div > span { display: block; font-size: 13px; line-height: 1.4; color: var(--muted); }
.visual-settings h2 { margin-bottom: 15px; }
.finish-picker { margin: 0 0 18px; }
.finish-options { display: grid; grid-template-columns: repeat(2, 1fr); gap: 5px; }
.finish-options label { position: relative; cursor: pointer; }
.finish-options input { position: absolute; opacity: 0; inset: 0; width: 100%; height: 100%; margin: 0; }
.finish-options span { display: block; padding: 9px 4px; border: 1px solid var(--control-border); border-radius: 4px; text-align: center; font-size: 14px; }
.finish-options input:checked + span { border-color: var(--text); background: var(--control-hover); box-shadow: inset 0 0 0 .5px var(--text); }
.finish-options input:focus-visible + span { outline: 2px solid var(--text); outline-offset: 3px; }
.legend li { gap: 7px; }
.setting { display: grid; grid-template-columns: 1fr auto; align-items: center; gap: 6px 12px; margin-top: 12px; }
.setting label { font-size: 14px; }
.setting output { color: var(--muted); font-size: 13px; font-variant-numeric: tabular-nums; }
.setting input { grid-column: 1 / -1; width: 100%; }
input[type=range] { accent-color: var(--accent); height: 18px; margin: 0; cursor: pointer; }
input[type=range]:disabled { opacity: .4; cursor: default; }
.comparison { display: flex; align-items: center; gap: 9px; margin-top: 18px; font-size: 14px; cursor: pointer; }
.comparison input { accent-color: var(--accent); width: 16px; height: 16px; margin: 0; }
#gap-note { margin-top: 12px; color: var(--muted); font-size: 12px; line-height: 1.5; }
@media (prefers-reduced-motion: reduce) { .piece.is-pressed .press-sheen { opacity: .16; } }
footer { margin-top: 27px; padding-top: 18px; border-top: 1px solid var(--line); font-size: 12px; color: var(--muted); line-height: 1.5; }
.sr-only { position: absolute; width: 1px; height: 1px; padding: 0; margin: -1px; overflow: hidden; clip: rect(0,0,0,0); white-space: nowrap; border: 0; }
#error { margin-top: 16px; font-size: 14px; line-height: 1.5; }
#error[hidden] { display: none; }
@media (min-width: 1700px) { .workspace { grid-template-columns: minmax(0, 1fr) 370px; gap: 52px; } .app { padding: 28px 48px; } .control-panel { padding-left: 36px; } }
@media (max-width: 1000px) { .app { padding: 22px 24px; } .workspace { gap: 24px; grid-template-columns: minmax(0, 1fr) 304px; } .control-panel { padding-left: 20px; } .element-options { grid-template-columns: repeat(2, 1fr); } .prototype { display: none; } }
@media (max-width: 740px) { .app { padding: 20px; } .workspace { grid-template-columns: 1fr; gap: 30px; } .control-panel { padding: 26px 0 0; border-left: 0; border-top: 1px solid var(--line); } .workspace-title { gap: 16px; } h1 { padding-left: 16px; font-size: 18px; } .brand { font-size: 28px; } .mosaic-stage { min-height: 0; } .preview-toolbar { gap: 8px; } .preview-toolbar input { flex: 1; width: 90px; } .element-options { grid-template-columns: repeat(4, 1fr); } .legend { grid-template-columns: repeat(2, 1fr); } .legend div { display: block; } }
@media (max-width: 370px) { .workspace-title { gap: 10px; } h1 { font-size: 16px; padding-left: 10px; } .brand { font-size: 26px; } .element-options { grid-template-columns: repeat(2, 1fr); } .legend { grid-template-columns: 1fr; } }