:root {
    --bg: #0b0d12;
    --panel: #12151c;
    --raised: #1a1e27;
    --sunken: #0e1117;
    --hover: #232836;
    --border: #262b36;
    --text: #d8dce4;
    --muted: #8a92a3;
    --accent: #f0b54a;
    --accent-soft: rgb(240 181 74 / 0.14);
    --danger: #e0786b;
    --radius: 6px;
    color-scheme: dark;
}

* {
    box-sizing: border-box;
}

html,
body {
    margin: 0;
    height: 100%;
    overflow: hidden;
    background: var(--bg);
    color: var(--text);
    font: 13px/1.4 system-ui, sans-serif;
}

body {
    display: flex;
}

[hidden] {
    display: none !important;
}

/* The sidebar */

#panel {
    flex: none;
    width: 272px;
    height: 100%;
    overflow-y: auto;
    padding: 12px;
    display: flex;
    flex-direction: column;
    gap: 12px;
    background: var(--panel);
    border-right: 1px solid var(--border);
    user-select: none;
    scrollbar-width: thin;
    scrollbar-color: var(--border) transparent;
}

header {
    display: flex;
    align-items: baseline;
    gap: 8px;
}

h1 {
    margin: 0;
    font-size: 18px;
    letter-spacing: 0.02em;
}

h3 {
    margin: 0 0 5px;
    font-size: 11px;
    font-weight: 600;
    text-transform: uppercase;
    letter-spacing: 0.08em;
    color: var(--muted);
}

.stats {
    margin-left: auto;
    color: var(--muted);
    font-size: 11px;
    font-variant-numeric: tabular-nums;
}

button {
    font: inherit;
    color: var(--text);
    background: var(--raised);
    border: 1px solid var(--border);
    border-radius: var(--radius);
    padding: 5px 8px;
    cursor: pointer;
    transition: background 0.1s, border-color 0.1s;
}

button:hover {
    background: var(--hover);
}

button.active {
    border-color: var(--accent);
    background: var(--accent-soft);
    box-shadow: inset 0 0 0 1px var(--accent);
}

button:focus-visible,
select:focus-visible,
input:focus-visible {
    outline: 2px solid var(--accent);
    outline-offset: 1px;
}

button.danger:hover {
    border-color: var(--danger);
    color: var(--danger);
}

.icon {
    display: grid;
    place-items: center;
    padding: 0;
}

svg {
    width: 18px;
    height: 18px;
    fill: none;
    stroke: currentColor;
    stroke-width: 1.8;
    stroke-linecap: round;
    stroke-linejoin: round;
}

.shape[data-shape="spray"] svg circle {
    fill: currentColor;
    stroke: none;
}

select {
    font: inherit;
    min-width: 0;
    color: var(--text);
    background: var(--raised);
    border: 1px solid var(--border);
    border-radius: var(--radius);
    padding: 4px 6px;
}

input[type="range"] {
    width: 100%;
    min-width: 0;
    margin: 0;
    accent-color: var(--accent);
}

kbd {
    font: 11px ui-monospace, monospace;
    padding: 0 4px;
    border: 1px solid var(--border);
    border-radius: 3px;
    background: var(--raised);
    color: var(--muted);
}

/* Pause, step, the view and clear */

.transport {
    display: grid;
    grid-template-columns: 34px 34px 1fr 34px;
    gap: 4px;
}

.transport button {
    height: 30px;
}

/* The brush card, which stays in view */

.card {
    position: sticky;
    top: -12px;
    z-index: 1;
    margin: 0 -4px;
    padding: 10px;
    display: flex;
    flex-direction: column;
    gap: 8px;
    background: var(--raised);
    border: 1px solid var(--border);
    border-radius: 9px;
    box-shadow: 0 6px 14px -6px rgb(0 0 0 / 0.6);
}

.brush-head {
    display: flex;
    align-items: center;
    gap: 10px;
    min-height: 36px;
}

.swatch {
    flex: none;
    display: grid;
    place-items: center;
    width: 32px;
    height: 32px;
    border-radius: 7px;
    background: var(--swatch);
    color: var(--accent);
    box-shadow: inset 0 0 0 1px rgb(255 255 255 / 0.15);
}

.swatch svg {
    width: 22px;
    height: 22px;
}

.brush-text {
    min-width: 0;
}

.brush-name {
    font-size: 14px;
    font-weight: 600;
}

.brush-note {
    color: var(--muted);
    font-size: 11px;
    line-height: 1.3;
    display: -webkit-box;
    -webkit-line-clamp: 2;
    -webkit-box-orient: vertical;
    overflow: hidden;
}

.tools {
    display: grid;
    grid-template-columns: repeat(7, 1fr);
    gap: 3px;
}

.tool {
    height: 32px;
    background: var(--sunken);
}

.option,
.field {
    display: grid;
    grid-template-columns: 52px 1fr auto;
    align-items: center;
    gap: 8px;
}

.option .segmented {
    grid-column: 2 / 4;
}

.pair {
    grid-column: 2 / 4;
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 4px;
}

.label {
    color: var(--muted);
    font-size: 12px;
}

.field select {
    grid-column: 2 / 4;
}

.field output,
.value {
    min-width: 42px;
    text-align: right;
    font-variant-numeric: tabular-nums;
    font-size: 12px;
}

.value {
    padding: 1px 6px;
    border-radius: 10px;
    background: var(--sunken);
}

.segmented {
    display: flex;
    border: 1px solid var(--border);
    border-radius: var(--radius);
    overflow: hidden;
    background: var(--sunken);
}

.segmented button {
    flex: 1;
    border: none;
    border-radius: 0;
    background: transparent;
    padding: 4px 0;
    font-size: 12px;
}

.segmented button + button {
    border-left: 1px solid var(--border);
}

.segmented button:hover {
    background: var(--hover);
}

.segmented button.active {
    background: var(--accent-soft);
    color: var(--accent);
    box-shadow: none;
}

.shapes button {
    height: 28px;
}

.over-element {
    margin-left: 60px;
}

/* The elements */

.elements-section {
    display: flex;
    flex-direction: column;
    gap: 10px;
}

input[type="search"] {
    font: inherit;
    width: 100%;
    color: var(--text);
    background: var(--sunken);
    border: 1px solid var(--border);
    border-radius: var(--radius);
    padding: 6px 9px;
}

input[type="search"]::placeholder {
    color: var(--muted);
}

#palette {
    display: flex;
    flex-direction: column;
    gap: 10px;
}

.elements {
    display: grid;
    grid-template-columns: repeat(2, 1fr);
    gap: 4px;
}

.element {
    display: flex;
    align-items: center;
    gap: 7px;
    padding: 4px 7px;
    text-align: left;
    white-space: nowrap;
    overflow: hidden;
    text-overflow: ellipsis;
}

.element::before {
    content: "";
    flex: none;
    width: 12px;
    height: 12px;
    border-radius: 3px;
    background: var(--swatch);
    box-shadow: inset 0 0 0 1px rgb(255 255 255 / 0.15);
}

/* Scenes, the world's settings and the shortcuts: collapsible */

.panel-section > summary {
    display: flex;
    align-items: center;
    gap: 6px;
    padding: 4px 0;
    font-size: 11px;
    font-weight: 600;
    text-transform: uppercase;
    letter-spacing: 0.08em;
    color: var(--muted);
    cursor: pointer;
    list-style: none;
}

.panel-section > summary::-webkit-details-marker,
.scene-group summary::-webkit-details-marker {
    display: none;
}

.panel-section > summary::before,
.scene-group summary::before {
    content: "▸";
    width: 10px;
    color: var(--muted);
    transition: transform 0.15s;
}

.panel-section[open] > summary::before,
.scene-group[open] summary::before {
    transform: rotate(90deg);
}

.panel-section > summary:hover {
    color: var(--text);
}

.scene-groups {
    display: flex;
    flex-direction: column;
    gap: 2px;
    padding-top: 2px;
}

.scene-group summary {
    display: flex;
    align-items: center;
    gap: 6px;
    padding: 4px 2px;
    border-radius: 4px;
    cursor: pointer;
    list-style: none;
}

.scene-group summary:hover {
    background: var(--raised);
}

.scene-group .count {
    margin-left: auto;
    color: var(--muted);
    font-size: 11px;
}

.scenes {
    display: grid;
    grid-template-columns: repeat(2, 1fr);
    gap: 4px;
    padding: 2px 0 6px;
}

.scene {
    text-align: left;
    white-space: nowrap;
    overflow: hidden;
    text-overflow: ellipsis;
}

.settings {
    display: flex;
    flex-direction: column;
    gap: 8px;
    padding: 4px 0 2px;
}

.check {
    display: flex;
    align-items: center;
    gap: 6px;
}

.check input {
    accent-color: var(--accent);
    margin: 0;
}

.help {
    color: var(--muted);
    font-size: 12px;
}

.help dl {
    display: grid;
    grid-template-columns: auto 1fr;
    gap: 4px 10px;
    margin: 6px 0;
}

.help dt {
    color: var(--text);
    white-space: nowrap;
}

.help dd {
    margin: 0;
}

.help p {
    margin: 6px 0 0;
}

/* The world */

#stage {
    position: relative;
    flex: 1;
    min-width: 0;
}

#view {
    display: block;
    width: 100%;
    height: 100%;
    cursor: none;
    touch-action: none;
    outline: none;  /* focused while drawing (ui.js), which needs no ring */
}

#hover {
    position: absolute;
    left: 10px;
    bottom: 10px;
    padding: 3px 8px;
    border-radius: 4px;
    background: rgb(0 0 0 / 0.55);
    color: var(--text);
    font-size: 12px;
    font-variant-numeric: tabular-nums;
    pointer-events: none;
}

#hover:empty {
    display: none;
}

#perf {
    position: absolute;
    top: 10px;
    right: 10px;
    margin: 0;
    padding: 6px 10px;
    border-radius: 4px;
    background: rgb(0 0 0 / 0.55);
    color: var(--text);
    font: 12px/1.5 ui-monospace, monospace;
    pointer-events: none;
}

#toast {
    position: absolute;
    top: 12px;
    left: 50%;
    max-width: min(520px, calc(100% - 32px));
    padding: 8px 14px;
    border: 1px solid var(--border);
    border-radius: 6px;
    background: rgb(18 21 28 / 0.9);
    color: var(--text);
    font-size: 13px;
    text-align: center;
    pointer-events: none;
    transform: translateX(-50%);
    opacity: 0;
    transition: opacity 0.4s;
}

#toast.visible {
    opacity: 1;
}

/* With the tour's card open, in the room left of it. */
.touring #toast {
    left: calc((100% - 344px) / 2);
    max-width: min(520px, calc(100% - 376px));
}

/* The guided tour (tour.js): a card over the world's top right corner, and
   the control a step is about outlined. */

.tour {
    position: absolute;
    top: 12px;
    right: 12px;
    z-index: 2;
    width: min(320px, calc(100% - 24px));
    padding: 12px 14px;
    border: 1px solid var(--border);
    border-radius: 9px;
    background: rgb(18 21 28 / 0.95);
    box-shadow: 0 8px 24px -8px rgb(0 0 0 / 0.7);
}

.tour-progress {
    font-size: 11px;
    font-weight: 600;
    text-transform: uppercase;
    letter-spacing: 0.08em;
    color: var(--muted);
}

.tour.done .tour-progress::after {
    content: " · done";
    color: var(--accent);
}

.tour h2 {
    margin: 2px 0 6px;
    font-size: 15px;
}

.tour p {
    margin: 0 0 12px;
}

.tour-buttons {
    display: flex;
    justify-content: flex-end;
    gap: 6px;
}

.tour-next {
    border-color: var(--accent);
    color: var(--accent);
}

.tour.done .tour-next {
    background: var(--accent-soft);
}

.tour-target {
    outline: 2px solid var(--accent);
    outline-offset: 2px;
    animation: tour-pulse 1.4s ease-in-out infinite;
}

@keyframes tour-pulse {
    50% {
        outline-color: rgb(240 181 74 / 0.25);
    }
}

.tour-open {
    align-self: center;
    width: 22px;
    height: 22px;
    padding: 0;
    border-radius: 50%;
    font-weight: 600;
    line-height: 1;
}

#error {
    position: absolute;
    inset: 0;
    margin: auto;
    width: min(560px, 90%);
    height: fit-content;
    padding: 16px 20px;
    border: 1px solid #6b2a2a;
    border-radius: 8px;
    background: #1d1214;
    color: #f2c4c4;
    font: 13px/1.5 ui-monospace, monospace;
    white-space: pre-wrap;
}

@media (max-width: 700px) {
    body {
        flex-direction: column-reverse;
    }

    #panel {
        width: 100%;
        height: 45%;
        border-right: none;
        border-top: 1px solid var(--border);
    }

    .elements {
        grid-template-columns: repeat(3, 1fr);
    }
}