:root {
  --r-background-color: #000000;
  --r-main-color: #f2f2f2;
  --r-heading-color: #ffffff;
  --r-link-color: #8ec5ff;
  --r-selection-background-color: #1f4e79;
}

.reveal {
  font-size: 32px;
}

.reveal h1,
.reveal h2,
.reveal h3,
.reveal h4 {
  text-transform: none;
  letter-spacing: 0.01em;
  font-weight: 600;
}

.reveal .subtitle,
.reveal .quarto-title-author,
.reveal .quarto-title-affiliation {
  color: #d0d0d0;
}

.reveal .slide-logo {
  display: block !important;
  position: fixed !important;
  top: 18px !important;
  left: 18px !important;
  right: auto !important;
  bottom: auto !important;
  max-height: 54px !important;
  max-width: 140px !important;
  z-index: 1000 !important;
}

.reveal .slide-number {
  color: #d8d8d8 !important;
  font-size: 0.55em !important;
}

.reveal ul {
  display: inline-block;
  text-align: left;
}

.reveal .columns {
  align-items: center;
}


А в `styles.css` добавь:

```css id="9u6f8e"
/* only this slide/widget */
.fit-widget input,
.fit-widget select,
.fit-widget button {
  color: #111 !important;
  background: #f2f2f2 !important;
  border: 1px solid #999 !important;
}

.fit-widget input[type="number"] {
  color: #111 !important;
  background: #f2f2f2 !important;
}

.fit-widget button {
  color: #111 !important;
  font-weight: 600;
}

.fit-widget label,
.fit-widget .observablehq,
.fit-widget .observablehq--inspect {
  color: #fff !important;
}


---

### CSS

Добавь в `styles.css`:

```css
.fit-widget input,
.fit-widget select,
.fit-widget button {
  color: #111 !important;
  background: #f2f2f2 !important;
  border: 1px solid #999 !important;
}

.fit-widget button {
  font-weight: 600;
}

.fit-widget label,
.fit-widget .observablehq,
.fit-widget .observablehq--inspect {
  color: #fff !important;
}

/* =========================================
   Elegant blocks for black Reveal.js slides
   ========================================= */

.reveal .slides section .callout {
  margin-top: 0.8em;
  margin-bottom: 0.8em;
  border-radius: 16px;
  border-left-width: 6px;
  background: rgba(255,255,255,0.06);
  box-shadow: none;
}

.reveal .slides section .callout .callout-header {
  background: transparent !important;
  border-bottom: 1px solid rgba(255,255,255,0.10);
  padding-bottom: 0.35em;
  margin-bottom: 0.45em;
}

.reveal .slides section .callout .callout-title {
  font-size: 0.95em;
  font-weight: 700;
  letter-spacing: 0.02em;
  text-transform: none;
}

.reveal .slides section .callout .callout-body {
  font-size: 0.88em;
  line-height: 1.35;
}

/* Definition */
.reveal .slides section .defbox {
  border-left-color: #4ea1ff !important;
  background: rgba(78,161,255,0.10) !important;
}

/* Theorem */
.reveal .slides section .thmbox {
  border-left-color: #b388ff !important;
  background: rgba(179,136,255,0.10) !important;
}

/* Exercise / Task */
.reveal .slides section .exbox {
  border-left-color: #ffb74d !important;
  background: rgba(255,183,77,0.10) !important;
}

/* Solution */
.reveal .slides section .solbox {
  border-left-color: #66bb6a !important;
  background: rgba(102,187,106,0.10) !important;
}

/* Remark */
.reveal .slides section .remarkbox {
  border-left-color: #90a4ae !important;
  background: rgba(144,164,174,0.12) !important;
}

/* Proof */
.reveal .slides section .proofbox {
  border-left-color: #ef5350 !important;
  background: rgba(239,83,80,0.10) !important;
}

/* Slightly more compact math inside boxes */
.reveal .slides section .callout p,
.reveal .slides section .callout li {
  margin-top: 0.25em;
  margin-bottom: 0.25em;
}

.reveal .slides section .callout ul,
.reveal .slides section .callout ol {
  margin-top: 0.35em;
  margin-bottom: 0.1em;
}