Niveus: a tactile, adaptive interface language

Bevelled controls with light falling across them, fields as wells, solid
windows, and glass kept for the chrome that floats over everything else.
Warm graphite in dark, soft paper in light, one brand color driving both.
Ships its own fonts (Instrument Sans, JetBrains Mono; OFL).

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

examples/ai-landing/app.css

@@ -0,0 +1,186 @@
+/* ==========================================================================
+   Lumen — page layout
+   --------------------------------------------------------------------------
+   Everything in this file is *layout*: where things sit, how wide they get,
+   when they stack. Not one color, shadow, radius, type size or duration is
+   stated here — those all come from Niveus, which is the whole point of the
+   split. If you find yourself writing a hex value in a file like this, the
+   system is missing a token.
+   ========================================================================== */
+
+.shell {
+  max-inline-size: var(--nv-layout-max-width);
+  margin-inline: auto;
+  padding-inline: var(--nv-layout-gutter);
+}
+
+.section {
+  padding-block: var(--nv-space-20);
+}
+
+.section__head {
+  max-inline-size: var(--nv-measure);
+  margin-block-end: var(--nv-space-8);
+  display: flex;
+  flex-direction: column;
+  gap: var(--nv-space-3);
+}
+
+.section__head--center {
+  margin-inline: auto;
+  text-align: center;
+  align-items: center;
+}
+
+/* --- Hero ------------------------------------------------------------------ */
+
+.hero {
+  display: grid;
+  gap: var(--nv-space-12);
+  padding-block: var(--nv-space-16) var(--nv-space-8);
+  align-items: center;
+}
+
+@media (min-width: 62rem) {
+  .hero {
+    grid-template-columns: 1fr 1fr;
+    gap: var(--nv-space-16);
+  }
+}
+
+.hero__copy {
+  display: flex;
+  flex-direction: column;
+  gap: var(--nv-space-5);
+  align-items: flex-start;
+}
+
+.hero__title {
+  font-size: clamp(var(--nv-font-size-4xl), 6vw, var(--nv-font-size-5xl));
+}
+
+/* --- Preview ---------------------------------------------------------------
+   A mock of the product, sitting on a bed so the frosted panel above it has
+   something to be frosted against. */
+
+.preview {
+  display: flex;
+  flex-direction: column;
+  gap: var(--nv-space-3);
+  max-inline-size: 30rem;
+  margin-inline: auto;
+}
+
+.bubble {
+  padding: var(--nv-space-3) var(--nv-space-4);
+  border-radius: var(--nv-radius-lg);
+  max-inline-size: 85%;
+}
+
+.bubble--from-user {
+  align-self: flex-end;
+  border-end-end-radius: var(--nv-radius-xs);
+}
+
+.bubble--from-agent {
+  align-self: flex-start;
+  border-end-start-radius: var(--nv-radius-xs);
+}
+
+/* --- Logos ------------------------------------------------------------------ */
+
+.logos {
+  display: flex;
+  flex-wrap: wrap;
+  gap: var(--nv-space-8);
+  justify-content: center;
+  align-items: center;
+  padding-block: var(--nv-space-8);
+  opacity: 0.75;
+}
+
+/* --- Features ---------------------------------------------------------------- */
+
+.features {
+  display: grid;
+  grid-template-columns: repeat(auto-fit, minmax(min(17rem, 100%), 1fr));
+  gap: var(--nv-space-5);
+}
+
+.feature__icon {
+  inline-size: var(--nv-space-10);
+  block-size: var(--nv-space-10);
+  display: grid;
+  place-items: center;
+  margin-block-end: var(--nv-space-4);
+  border-radius: var(--nv-radius-md);
+  background-color: var(--nv-color-accent-subtle);
+  color: var(--nv-color-accent-text);
+}
+
+.feature__icon svg {
+  inline-size: var(--nv-space-5);
+  block-size: var(--nv-space-5);
+}
+
+/* --- Pricing ------------------------------------------------------------------ */
+
+.pricing {
+  display: grid;
+  grid-template-columns: repeat(auto-fit, minmax(min(17rem, 100%), 1fr));
+  gap: var(--nv-space-5);
+  align-items: start;
+}
+
+.price {
+  display: flex;
+  align-items: baseline;
+  gap: var(--nv-space-2);
+  margin-block: var(--nv-space-4);
+}
+
+.price__amount {
+  font-size: var(--nv-font-size-4xl);
+  font-weight: var(--nv-font-weight-semibold);
+  letter-spacing: var(--nv-letter-spacing-tighter);
+  color: var(--nv-color-text-primary);
+}
+
+.plan-features {
+  list-style: none;
+  margin: 0;
+  padding: 0;
+  display: flex;
+  flex-direction: column;
+  gap: var(--nv-space-2-5);
+}
+
+.plan-features li {
+  display: flex;
+  align-items: flex-start;
+  gap: var(--nv-space-2-5);
+}
+
+.plan-features svg {
+  inline-size: 1em;
+  block-size: 1em;
+  margin-block-start: 0.25em;
+  flex: none;
+  color: var(--nv-color-success-text);
+}
+
+/* --- Closing ------------------------------------------------------------------- */
+
+.closing {
+  text-align: center;
+  display: flex;
+  flex-direction: column;
+  align-items: center;
+  gap: var(--nv-space-5);
+  padding-block: var(--nv-space-12);
+}
+
+.site-footer {
+  padding-block: var(--nv-space-8) var(--nv-space-12);
+  border-block-start: var(--nv-border-width) solid var(--nv-color-border-subtle);
+}