uBlock/platform/mv3/extension/css/develop.css

body[data-pane="develop"] {
    height: 100vh;
    }

section[data-pane="develop"] {
    display: none;
    flex-grow: 1;
    overflow: hidden;
    }

section[data-pane="develop"] > div {
    display: flex;
    flex-direction: column;
    height: 100%;
    }

section[data-pane="develop"] > div > * {
    margin-bottom: 0;
    margin-top: 1em;
    }

#cm-dnrRules {
    flex-grow: 1;
    font-size: var(--monospace-size);
    overflow: hidden;
    }

/* https://discuss.codemirror.net/t/how-to-set-max-height-of-the-editor/2882/2 */
#cm-dnrRules .cm-editor {
    background-color: var(--surface-0);
    height: 100%;
    }

#cm-dnrRules .cm-editor .cm-line {
    border-bottom: 1px dotted transparent;
    border-top: 1px dotted transparent;
    }

#cm-dnrRules .cm-editor .cm-line:has(.ͼc) {
    border-bottom: 1px dotted var(--border-1);
    border-top: 1px dotted var(--border-1);
    }

#cm-dnrRules .cm-editor .cm-line.badline:not(.cm-activeLine) {
    background-color: color-mix(in srgb, var(--info3-ink) 15%, transparent 85%);
    }

#cm-dnrRules .cm-editor .cm-line .badmark {
    text-decoration: underline var(--cm-negative) wavy;
    text-decoration-skip-ink: none;
    }

#cm-dnrRules .cm-editor .cm-panel.cm-search {
    display: flex;
    flex-wrap: wrap;
    font-family: sans-serif;
    font-size: var(--font-size);
    gap: 0.5em 1em;
    padding: 0.5em 1.5em 0.5em 0.5em;
    }

#cm-dnrRules .cm-editor .cm-panel.cm-search > * {
    margin: 0;
    }

#cm-dnrRules .cm-editor .cm-panel.cm-search .cm-textfield,
#cm-dnrRules .cm-editor .cm-panel.cm-search .cm-button,
#cm-dnrRules .cm-editor .cm-panel.cm-search label {
    background-image: inherit;
    border: inherit;
    flex-grow: 0;
    font-size: var(--button-font-size);
    min-height: calc(var(--button-font-size) * 1.8);
    }

#cm-dnrRules .cm-editor .cm-panel.info-panel {
    display: flex;
    flex-wrap: nowrap;
    font-size: var(--font-size);
    padding: var(--default-gap-xxsmall) var(--default-gap-xsmall);
    }
#cm-dnrRules .cm-editor .cm-panel.info-panel .info {
    flex-grow: 1;
    overflow: auto;
    }
#cm-dnrRules .cm-editor .cm-panel.info-panel .close {
    cursor: default;
    flex-shrink: 0;
    padding-inline-start: 1em;
    }
#cm-dnrRules .cm-editor .cm-panel.info-panel .close::after {
    content: '\2715';
    }
#cm-dnrRules .cm-editor .cm-panel.summary-panel {
    background-color: color-mix(in srgb, var(--info1-ink) 15%, transparent 85%);
    }

#cm-dnrRules .cm-editor .cm-panel.feedback-panel {
    background-color: color-mix(in srgb, var(--info3-ink) 15%, transparent 85%);
    white-space: pre;
    max-height: 10cqh;
    }

#cm-dnrRules .cm-editor .cm-gutterElement {
    cursor: default;
    user-select: none;
    }

#cm-dnrRules .cm-editor .cm-tooltip .badmark-tooltip {
    background-color: color-mix(in srgb, var(--info3-ink) 15%, transparent 85%);
    padding: var(--default-gap-xxsmall) var(--default-gap-xsmall);
    }