/* =====================================================================
   App pages (Software menu). Each app page wears the app's own look
   rather than the site's paper: the CMT Drone Service Utility palette
   (near-black navy, slate panels, iOS blue), Outfit titles, Inter text,
   numbered section labels and 16px corners.
   ===================================================================== */

.app-page {
  --dsu-bg: #0b0e14;
  --dsu-panel: #151921;
  --dsu-panel-2: #11161e;
  --dsu-border: #263238;
  --dsu-accent: #007aff;
  --dsu-accent-2: #60a5fa;
  --dsu-accent-soft: rgba(0, 122, 255, 0.13);
  --dsu-text: #f8fafc;
  --dsu-muted: #94a3b8;
  --dsu-dim: #64748b;
  --dsu-success: #22c55e;
  --dsu-radius: 16px;
  background: var(--dsu-bg);
  color: var(--dsu-text);
}

.dsu {
  font-family: "Inter", "Segoe UI", sans-serif;
  background:
    radial-gradient(1100px 620px at 78% -4%, rgba(0, 122, 255, 0.16), transparent 60%),
    var(--dsu-bg);
}

.dsu .crumbs {
  color: var(--dsu-muted);
}

.crumbs a + a::before {
  content: "·";
  margin-right: 10px;
}

/* small spaced labels, as in the app */
.dsu-label {
  display: inline-flex;
  align-items: center;
  gap: 10px;
  font-size: 11px;
  font-weight: 700;
  letter-spacing: 0.16em;
  text-transform: uppercase;
  color: var(--dsu-accent-2);
}

.dsu-label i {
  width: 6px;
  height: 6px;
  border-radius: 50%;
  background: var(--dsu-accent);
  box-shadow: 0 0 0 4px var(--dsu-accent-soft);
}

/* section numbers: "01 / Inside the workspace" */
.dsu-num {
  font-family: var(--f-mono);
  font-size: 11.5px;
  letter-spacing: 0.14em;
  text-transform: uppercase;
  color: var(--dsu-accent-2);
}

/* two-tone headings: the second half steps back in grey */
.dsu-h2 {
  margin-top: 12px;
  font-family: var(--f-display);
  font-size: clamp(2rem, 4.2vw, 3.4rem);
  font-weight: 700;
  line-height: 1.04;
  letter-spacing: -0.035em;
}

.dsu-h2 span {
  display: block;
  color: #7c8aa0;
}

.dsu-head {
  display: grid;
  grid-template-columns: 1fr minmax(260px, 0.6fr);
  align-items: end;
  gap: 24px 56px;
  margin-bottom: clamp(28px, 4vw, 44px);
}

.dsu-head > p {
  font-size: 16px;
  line-height: 1.7;
  color: var(--dsu-muted);
}

.dsu-head--center {
  grid-template-columns: 1fr;
  justify-items: center;
  text-align: center;
}

.dsu-head--center > p {
  max-width: 56ch;
}

.dsu-fine {
  margin-top: 14px;
  font-size: 13px;
  line-height: 1.6;
  color: var(--dsu-dim);
}

.dsu-link {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  font-weight: 700;
  color: var(--dsu-accent-2);
  transition: gap 0.3s var(--ease), color 0.25s ease;
}

.dsu-link:hover {
  gap: 12px;
  color: var(--dsu-text);
}

/* ---------- buttons, shaped like the app's ---------- */
.dsu-actions {
  display: flex;
  flex-wrap: wrap;
  gap: 12px;
}

.dsu-btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 10px;
  padding: 13px 20px;
  border-radius: 12px;
  border: 1px solid var(--dsu-border);
  background: var(--dsu-panel);
  font-family: "Inter", sans-serif;
  font-size: 15px;
  font-weight: 700;
  color: var(--dsu-text);
  transition: border-color 0.25s ease, background-color 0.25s ease, transform 0.35s var(--ease);
}

.dsu-btn:hover {
  border-color: #3b4a55;
  transform: translateY(-2px);
}

.dsu-btn--primary {
  border-color: var(--dsu-accent);
  background: var(--dsu-accent);
  box-shadow: 0 10px 30px rgba(0, 122, 255, 0.35);
}

.dsu-btn--primary:hover {
  border-color: #2b8fff;
  background: #2b8fff;
}

.dsu-btn i {
  font-size: 18px;
}

/* ---------- window frame around a screenshot ---------- */
.dsu-frame {
  overflow: hidden;
  border-radius: 20px;
  border: 1px solid var(--dsu-border);
  background: var(--dsu-panel-2);
}

.dsu-frame img {
  width: 100%;
  height: auto;
  aspect-ratio: 1440 / 900;
  object-fit: cover;
  object-position: top left;
}

.dsu-frame__bar {
  display: flex;
  align-items: center;
  gap: 14px;
  padding: 14px 20px;
  border-bottom: 1px solid var(--dsu-border);
  font-family: var(--f-mono);
  font-size: 11px;
  letter-spacing: 0.14em;
  text-transform: uppercase;
  color: var(--dsu-muted);
}

.dsu-frame__bar b {
  color: var(--dsu-text);
}

.dsu-frame__bar em {
  margin-left: auto;
  padding: 5px 10px;
  border-radius: 8px;
  border: 1px solid var(--dsu-border);
  font-style: normal;
  color: var(--dsu-accent-2);
}

.dsu-frame__foot {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  justify-content: space-between;
  gap: 10px 24px;
  padding: 14px 20px;
  border-top: 1px solid var(--dsu-border);
  font-family: var(--f-mono);
  font-size: 11px;
  letter-spacing: 0.14em;
  text-transform: uppercase;
  color: var(--dsu-muted);
}

.dsu-frame__foot i {
  margin: 0 4px;
  color: var(--dsu-accent-2);
}

.dsu-frame__foot a {
  color: var(--dsu-text);
  transition: color 0.25s ease;
}

.dsu-frame__foot a:hover {
  color: var(--dsu-accent-2);
}

/* ---------- HERO ---------- */
.dsu-hero {
  padding: 150px 0 clamp(40px, 5vw, 64px);
}

.dsu-hero__grid {
  display: grid;
  grid-template-columns: 1fr minmax(300px, 0.48fr);
  align-items: end;
  gap: clamp(28px, 5vw, 80px);
}

.dsu-title {
  margin: 18px 0 30px;
  font-family: var(--f-display);
  font-size: clamp(2.4rem, 5vw, 4.4rem);
  font-weight: 700;
  line-height: 1.02;
  letter-spacing: -0.04em;
}

.dsu-title__sub {
  display: block;
  margin-top: 14px;
  font-size: 0.6em;
  letter-spacing: -0.03em;
  color: var(--dsu-accent-2);
}

/* "about the app", set apart by a rule on its left */
.dsu-about {
  padding-left: 28px;
  border-left: 1px solid var(--dsu-border);
}

.dsu-about h2 {
  margin: 10px 0 12px;
  font-family: var(--f-display);
  font-size: 1.5rem;
  font-weight: 700;
}

.dsu-about p {
  font-size: 15px;
  line-height: 1.7;
  color: var(--dsu-muted);
}

.dsu-about__fine {
  margin-top: 12px;
  font-size: 13.5px !important;
  color: var(--dsu-dim) !important;
}

.dsu-frame--hero {
  margin-top: clamp(40px, 5vw, 60px);
  box-shadow: 0 40px 100px -20px rgba(0, 122, 255, 0.25), 0 18px 50px rgba(0, 0, 0, 0.4);
}

/* the workflow in one line under the hero */
.dsu-strip {
  display: flex;
  flex-wrap: wrap;
  justify-content: space-between;
  gap: 12px 24px;
  margin-top: 26px;
  padding: 18px 4px;
  border-block: 1px solid var(--dsu-border);
  font-family: var(--f-mono);
  font-size: 11.5px;
  letter-spacing: 0.14em;
  text-transform: uppercase;
  color: var(--dsu-muted);
}

.dsu-strip li:first-child {
  color: var(--dsu-text);
}

/* ---------- SECTIONS ---------- */
.dsu-sec {
  padding: clamp(64px, 8vw, 110px) 0;
  scroll-margin-top: 70px;
}

.dsu-sec--line {
  border-top: 1px solid var(--dsu-border);
}

.dsu-sec--tight {
  padding-top: 0;
}

/* ---------- 01: the screen viewer ---------- */
.gallery {
  overflow: hidden;
  border-radius: 22px;
  border: 1px solid var(--dsu-border);
  background: var(--dsu-panel-2);
}

.gallery__top {
  display: flex;
  justify-content: space-between;
  gap: 16px;
  padding: 16px 22px;
  border-bottom: 1px solid var(--dsu-border);
  font-family: var(--f-mono);
  font-size: 11px;
  letter-spacing: 0.14em;
  text-transform: uppercase;
  color: var(--dsu-muted);
}

.gallery__top b {
  color: var(--dsu-text);
}

.gallery__top em {
  font-style: normal;
}

.gallery__thumbs {
  display: grid;
  grid-template-columns: repeat(10, minmax(108px, 1fr));
  gap: 10px;
  padding: 14px;
  border-bottom: 1px solid var(--dsu-border);
  overflow-x: auto;
  scrollbar-width: thin;
}

.gallery__thumbs button {
  display: grid;
  gap: 8px;
  padding: 6px 6px 9px;
  border-radius: 12px;
  border: 1px solid var(--dsu-border);
  background: var(--dsu-panel);
  text-align: left;
  cursor: pointer;
  transition: border-color 0.25s ease, background-color 0.25s ease;
}

.gallery__thumbs button:hover {
  border-color: #3b4a55;
}

.gallery__thumbs button.is-on {
  border-color: var(--dsu-accent);
  background: #13233d;
}

.gallery__thumbs img {
  width: 100%;
  aspect-ratio: 16 / 10;
  border-radius: 7px;
  object-fit: cover;
  object-position: top left;
  opacity: 0.75;
  transition: opacity 0.25s ease;
}

.gallery__thumbs button.is-on img,
.gallery__thumbs button:hover img {
  opacity: 1;
}

.gallery__thumbs span {
  padding: 0 4px;
  font-size: 12px;
  font-weight: 600;
  color: #cbd5e1;
  white-space: nowrap;
}

.gallery__stage {
  display: grid;
  grid-template-columns: minmax(0, 1.7fr) minmax(280px, 0.8fr);
}

.gallery__view {
  position: relative;
  display: block;
  padding: 18px;
  border-right: 1px solid var(--dsu-border);
  cursor: zoom-in;
}

.gallery__view img {
  width: 100%;
  height: auto;
  aspect-ratio: 1440 / 900;
  border-radius: 12px;
  border: 1px solid var(--dsu-border);
  object-fit: cover;
  object-position: top left;
  transition: opacity 0.25s ease;
}

.gallery__view img.is-swapping {
  opacity: 0;
}

.gallery__zoom {
  position: absolute;
  right: 30px;
  bottom: 30px;
  display: inline-flex;
  align-items: center;
  gap: 8px;
  padding: 9px 14px;
  border-radius: 10px;
  background: rgba(11, 14, 20, 0.85);
  border: 1px solid var(--dsu-border);
  font-size: 13px;
  font-weight: 600;
  opacity: 0;
  transform: translateY(6px);
  transition: opacity 0.25s ease, transform 0.35s var(--ease);
}

.gallery__view:hover .gallery__zoom,
.gallery__view:focus-visible .gallery__zoom {
  opacity: 1;
  transform: none;
}

.gallery__info {
  display: flex;
  flex-direction: column;
  justify-content: space-between;
  gap: 24px;
  padding: 26px;
}

.gallery__info h3 {
  margin: 12px 0 10px;
  font-family: var(--f-display);
  font-size: 1.55rem;
  font-weight: 700;
  line-height: 1.15;
  letter-spacing: -0.02em;
}

.gallery__info p:not(.dsu-label) {
  font-size: 15px;
  line-height: 1.65;
  color: var(--dsu-muted);
}

.gallery__points {
  display: grid;
  gap: 8px;
  margin-top: 18px;
}

.gallery__points li {
  display: flex;
  gap: 10px;
  font-size: 14px;
  color: #cbd5e1;
}

.gallery__points li::before {
  content: "";
  flex: none;
  width: 6px;
  height: 6px;
  margin-top: 8px;
  border-radius: 50%;
  background: var(--dsu-accent);
}

.gallery__nav {
  display: flex;
  align-items: center;
  gap: 14px;
}

.gallery__nav button {
  display: grid;
  place-items: center;
  width: 40px;
  height: 40px;
  border-radius: 10px;
  border: 1px solid var(--dsu-border);
  background: var(--dsu-panel);
  color: var(--dsu-text);
  font-size: 18px;
  cursor: pointer;
  transition: border-color 0.25s ease, background-color 0.25s ease;
}

.gallery__nav button:hover {
  border-color: var(--dsu-accent);
  background: #13233d;
}

.gallery__nav span {
  font-family: var(--f-mono);
  font-size: 12px;
  letter-spacing: 0.1em;
  color: var(--dsu-muted);
}

/* full-size screen */
.dsu-lightbox {
  width: min(1400px, 94vw);
  max-width: none;
  padding: 0;
  border: 1px solid var(--dsu-border);
  border-radius: 16px;
  background: var(--dsu-bg);
  overflow: hidden;
}

.dsu-lightbox::backdrop {
  background: rgba(3, 6, 12, 0.85);
  backdrop-filter: blur(4px);
}

.dsu-lightbox img {
  width: 100%;
  height: auto;
}

.dsu-lightbox button {
  position: absolute;
  top: 12px;
  right: 12px;
  display: grid;
  place-items: center;
  width: 40px;
  height: 40px;
  border-radius: 10px;
  border: 1px solid var(--dsu-border);
  background: rgba(11, 14, 20, 0.85);
  color: var(--dsu-text);
  font-size: 20px;
  cursor: pointer;
}

/* six strengths */
.dsu-feats {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 14px;
  margin-top: clamp(36px, 5vw, 56px);
}

.dsu-feat {
  padding: 26px;
  border-radius: var(--dsu-radius);
  border: 1px solid var(--dsu-border);
  background: var(--dsu-panel);
  transition: border-color 0.25s ease;
}

.dsu-feat:hover {
  border-color: rgba(0, 122, 255, 0.5);
}

.dsu-feat > i {
  display: grid;
  place-items: center;
  width: 44px;
  height: 44px;
  margin-bottom: 26px;
  border-radius: 12px;
  border: 1px solid #22344f;
  background: #121e31;
  color: var(--dsu-accent-2);
  font-size: 20px;
}

.dsu-feat h3 {
  margin: 10px 0 8px;
  font-family: var(--f-display);
  font-size: 1.25rem;
  font-weight: 700;
}

.dsu-feat > p:last-child {
  font-size: 14.5px;
  line-height: 1.65;
  color: var(--dsu-muted);
}

/* ---------- 02: how a job runs ---------- */
.dsu-flow {
  list-style: none;
  padding: 0;
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: clamp(20px, 3vw, 40px);
}

.dsu-flow li {
  position: relative;
  padding-top: 28px;
  border-top: 1px solid var(--dsu-border);
}

/* an arrow between steps, on the rule */
.dsu-flow li:not(:last-child)::after {
  content: "\2192";
  position: absolute;
  top: -12px;
  right: -6px;
  padding: 0 8px;
  background: var(--dsu-bg);
  color: var(--dsu-muted);
  font-size: 16px;
}

.dsu-flow b {
  display: grid;
  place-items: center;
  width: 40px;
  height: 40px;
  border-radius: 50%;
  border: 1px solid #22344f;
  background: #121e31;
  font-family: var(--f-mono);
  font-size: 12px;
  font-weight: 500;
  color: var(--dsu-accent-2);
}

.dsu-flow h3 {
  margin: 20px 0 8px;
  font-family: var(--f-display);
  font-size: 1.35rem;
  font-weight: 700;
}

.dsu-flow p {
  font-size: 15px;
  line-height: 1.65;
  color: var(--dsu-muted);
}

.dsu-flow small {
  display: block;
  margin-top: 18px;
  font-family: var(--f-mono);
  font-size: 11px;
  letter-spacing: 0.14em;
  text-transform: uppercase;
  color: var(--dsu-dim);
}

.dsu-callout {
  display: flex;
  gap: 14px;
  max-width: 820px;
  margin-top: clamp(32px, 4vw, 48px);
  padding: 18px 20px;
  border-radius: 14px;
  border: 1px solid var(--dsu-border);
  background: var(--dsu-panel);
  font-size: 14.5px;
  line-height: 1.6;
  color: var(--dsu-muted);
}

.dsu-callout i {
  font-size: 20px;
  color: var(--dsu-success);
}

.dsu-callout strong {
  color: var(--dsu-text);
}

/* ---------- 03: nine greetings ---------- */
.dsu-langs {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 12px;
}

.dsu-langs li {
  padding: 20px 22px;
  border-radius: var(--dsu-radius);
  border: 1px solid var(--dsu-border);
  background: linear-gradient(160deg, #111a2b, var(--dsu-panel));
  font-size: 11px;
  font-weight: 700;
  letter-spacing: 0.14em;
  text-transform: uppercase;
  color: var(--dsu-muted);
}

.dsu-langs b {
  display: block;
  margin-bottom: 6px;
  font-size: clamp(1.4rem, 2.4vw, 1.9rem);
  font-weight: 600;
  letter-spacing: -0.01em;
  text-transform: none;
  color: var(--dsu-text);
}

/* ---------- 04: model finder ---------- */
.models {
  overflow: hidden;
  border-radius: 20px;
  border: 1px solid var(--dsu-border);
  background: var(--dsu-panel-2);
}

.models__bar {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 14px 24px;
  padding: 16px;
  border-bottom: 1px solid var(--dsu-border);
}

.models__search {
  display: flex;
  flex: 1 1 320px;
  align-items: center;
  gap: 10px;
  padding: 0 14px;
  border-radius: 12px;
  border: 1px solid var(--dsu-border);
  background: var(--dsu-panel);
  color: var(--dsu-muted);
  transition: border-color 0.25s ease;
}

.models__search:focus-within {
  border-color: var(--dsu-accent);
}

.models__search input {
  flex: 1;
  padding: 13px 0;
  border: 0;
  background: none;
  font: inherit;
  font-size: 15px;
  color: var(--dsu-text);
  outline: none;
}

.models__count {
  font-size: 14px;
  color: var(--dsu-muted);
}

.models__count b {
  font-family: var(--f-display);
  font-size: 1.5rem;
  color: var(--dsu-text);
}

.models__list {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
}

.models__list li {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 16px;
  padding: 16px 22px;
  border-bottom: 1px solid rgba(38, 50, 56, 0.7);
}

.models__list li:nth-child(odd) {
  border-right: 1px solid rgba(38, 50, 56, 0.7);
}

.models__list li[hidden] {
  display: none;
}

.models__list strong {
  display: block;
  font-size: 15px;
}

.models__list code {
  font-family: var(--f-mono);
  font-size: 12px;
  color: var(--dsu-dim);
}

.models__list em {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  font-size: 13px;
  font-style: normal;
  color: var(--dsu-muted);
}

.models__list em::before {
  content: "";
  width: 7px;
  height: 7px;
  border-radius: 50%;
  background: var(--dsu-accent-2);
}

.models__list em.is-new::before {
  background: var(--dsu-success);
}

.models__empty {
  padding: 22px;
  color: var(--dsu-muted);
}

.models__empty a {
  color: var(--dsu-accent-2);
  text-decoration: underline;
}

/* ---------- 05: plans ---------- */
.dsu-plans {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 16px;
  max-width: 1080px;
  margin-inline: auto;
}

.dsu-plan {
  display: flex;
  flex-direction: column;
  padding: 28px;
  border-radius: 20px;
  border: 1px solid var(--dsu-border);
  background: var(--dsu-panel);
}

.dsu-plan--pick {
  border-color: var(--dsu-accent);
  background: linear-gradient(170deg, rgba(0, 122, 255, 0.18), var(--dsu-panel) 60%);
  box-shadow: 0 30px 60px -30px rgba(0, 122, 255, 0.5);
}

.dsu-plan .dsu-label span {
  padding: 3px 8px;
  border-radius: 6px;
  background: var(--dsu-accent);
  font-size: 10px;
  letter-spacing: 0.1em;
  color: var(--white);
}

.dsu-plan h3 {
  margin: 14px 0 4px;
  font-family: var(--f-display);
  font-size: 2.2rem;
  font-weight: 800;
  letter-spacing: -0.03em;
}

.dsu-plan > p:not(.dsu-label) {
  font-size: 14.5px;
  color: var(--dsu-muted);
}

.dsu-plan ul {
  display: grid;
  gap: 10px;
  margin: 22px 0 26px;
  padding-top: 20px;
  border-top: 1px solid var(--dsu-border);
}

.dsu-plan li {
  display: flex;
  align-items: center;
  gap: 10px;
  font-size: 14.5px;
  color: #cbd5e1;
}

.dsu-plan li::before {
  content: "\2713";
  display: grid;
  place-items: center;
  width: 18px;
  height: 18px;
  border-radius: 50%;
  background: var(--dsu-accent-soft);
  color: var(--dsu-accent-2);
  font-size: 11px;
  font-weight: 700;
}

.dsu-plan .dsu-btn {
  margin-top: auto;
}

.dsu-plan-notes {
  display: flex;
  flex-wrap: wrap;
  justify-content: center;
  gap: 10px 28px;
  margin-top: 24px;
  font-size: 13.5px;
  color: var(--dsu-muted);
}

.dsu-plan-notes li {
  display: inline-flex;
  align-items: center;
  gap: 8px;
}

.dsu-plan-notes i {
  color: var(--dsu-accent-2);
}

/* ---------- get the app ---------- */
.dsu-get {
  display: grid;
  grid-template-columns: auto 1fr;
  align-items: center;
  gap: clamp(24px, 4vw, 56px);
  padding: clamp(28px, 4vw, 56px);
  border-radius: 24px;
  border: 1px solid var(--dsu-border);
  background:
    radial-gradient(500px 260px at 0% 0%, rgba(0, 122, 255, 0.18), transparent 70%),
    var(--dsu-panel);
}

.dsu-get__icon {
  display: grid;
  justify-items: center;
  gap: 12px;
}

.dsu-get__icon img {
  width: 120px;
  height: 120px;
  padding: 24px;
  border-radius: 30px;
  border: 1px solid #22344f;
  background: linear-gradient(160deg, #13233d, #0b1220);
  box-shadow: 0 20px 50px rgba(0, 0, 0, 0.4);
}

.dsu-get__icon span {
  font-family: var(--f-mono);
  font-size: 11px;
  letter-spacing: 0.16em;
  text-transform: uppercase;
  color: var(--dsu-muted);
}

.dsu-get h2,
.dsu-support h2 {
  margin: 12px 0 10px;
  font-family: var(--f-display);
  font-size: clamp(1.8rem, 3.4vw, 2.6rem);
  font-weight: 700;
  line-height: 1.08;
  letter-spacing: -0.03em;
}

.dsu-get > div > p:not(.dsu-label):not(.dsu-fine) {
  max-width: 58ch;
  font-size: 15.5px;
  line-height: 1.7;
  color: var(--dsu-muted);
}

.dsu-tags {
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
  margin: 18px 0 24px;
}

.dsu-tags li {
  padding: 6px 10px;
  border-radius: 8px;
  border: 1px solid var(--dsu-border);
  font-family: var(--f-mono);
  font-size: 11.5px;
  color: #cbd5e1;
}

/* ---------- 06: questions ---------- */
.dsu-faq {
  display: grid;
  grid-template-columns: minmax(260px, 0.75fr) 1.25fr;
  gap: clamp(28px, 5vw, 80px);
  align-items: start;
}

.dsu-faq > div:first-child > p:not(.dsu-num) {
  margin: 16px 0 20px;
  font-size: 15.5px;
  line-height: 1.7;
  color: var(--dsu-muted);
}

.dsu-qa details {
  border-bottom: 1px solid var(--dsu-border);
}

.dsu-qa details:first-child {
  border-top: 1px solid var(--dsu-border);
}

.dsu-qa summary {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 16px;
  padding: 20px 2px;
  font-size: 16px;
  font-weight: 600;
  cursor: pointer;
  list-style: none;
}

.dsu-qa summary::-webkit-details-marker {
  display: none;
}

.dsu-qa summary::after {
  content: "+";
  flex: none;
  font-size: 22px;
  font-weight: 400;
  color: var(--dsu-accent-2);
  transition: transform 0.3s var(--ease);
}

.dsu-qa details[open] summary::after {
  transform: rotate(45deg);
}

.dsu-qa details p {
  padding: 0 2px 22px;
  max-width: 64ch;
  font-size: 15px;
  line-height: 1.7;
  color: var(--dsu-muted);
}

/* ---------- support ---------- */
.dsu-support {
  display: grid;
  grid-template-columns: 1.4fr 1fr;
  overflow: hidden;
  border-radius: 24px;
  border: 1px solid var(--dsu-border);
  background: var(--dsu-panel);
}

.dsu-support > div {
  padding: clamp(28px, 4vw, 56px);
}

.dsu-support h2 span {
  display: block;
  color: var(--dsu-accent-2);
}

.dsu-support > div > p:not(.dsu-label) {
  max-width: 50ch;
  margin-bottom: 24px;
  font-size: 15.5px;
  line-height: 1.7;
  color: var(--dsu-muted);
}

.dsu-support small {
  display: block;
  margin-top: 14px;
  font-family: var(--f-mono);
  font-size: 11.5px;
  color: var(--dsu-dim);
}

.dsu-support__side {
  position: relative;
  isolation: isolate;
  display: flex;
  flex-direction: column;
  justify-content: flex-end;
  border-left: 1px solid var(--dsu-border);
  background: var(--dsu-panel-2);
}

.dsu-support__side img {
  position: absolute;
  top: 20px;
  right: -40px;
  z-index: -1;
  width: 240px;
  opacity: 0.06;
}

.dsu-support__side h3 {
  margin: 10px 0 14px;
  font-family: var(--f-display);
  font-size: 1.6rem;
  font-weight: 700;
  line-height: 1.15;
}

/* ---------- the site header and menu, in the app's colours on this page ---------- */
.app-page .nav::before {
  background: rgba(21, 25, 33, 0.82);
  border-color: var(--dsu-border);
  box-shadow: 0 10px 30px rgba(0, 0, 0, 0.35);
}

/* the white version of the mark reads on the dark pill (same artwork, light colour) */
.app-page .logo img {
  content: url("../images/logo-mark-white.png");
}

.app-page .to-top {
  background: var(--dsu-panel);
  color: var(--dsu-text);
  box-shadow: 0 10px 30px rgba(0, 0, 0, 0.4);
}

.app-page .logo__text,
.app-page .nav__social-link {
  color: var(--dsu-text);
}

.app-page .nav__link {
  color: #cbd5e1;
}

.app-page .nav__link:hover {
  color: var(--dsu-text);
}

.app-page .nav__link.active {
  background: #13233d;
  color: var(--dsu-text);
  box-shadow: none;
}

.app-page .nav__toggle {
  background: var(--dsu-panel);
  box-shadow: none;
}

.app-page .hamburger span {
  background: var(--dsu-text);
}

@media (min-width: 1025px) {
  .app-page .nav__drop {
    background: var(--dsu-panel);
    border-color: var(--dsu-border);
    box-shadow: 0 24px 50px rgba(0, 0, 0, 0.45);
  }

  .app-page .nav__app strong {
    color: var(--dsu-text);
  }

  .app-page .nav__drop-label,
  .app-page .nav__app small {
    color: var(--dsu-muted);
  }

  .app-page a.nav__app:hover,
  .app-page a.nav__app.active {
    background: #13233d;
  }

  .app-page .nav__app-ico {
    background: var(--dsu-accent);
  }

  .app-page .nav__drop-foot {
    border-color: var(--dsu-border);
    color: #60a5fa;
  }
}

/* ---------- RESPONSIVE ---------- */
@media (max-width: 1100px) {
  .gallery__stage {
    grid-template-columns: 1fr;
  }

  .gallery__view {
    border-right: 0;
    border-bottom: 1px solid var(--dsu-border);
  }
}

@media (max-width: 1024px) {
  .dsu-hero {
    padding-top: 120px;
  }

  .dsu-hero__grid,
  .dsu-head,
  .dsu-faq,
  .dsu-support {
    grid-template-columns: 1fr;
  }

  .dsu-about {
    padding-left: 0;
    padding-top: 24px;
    border-left: 0;
    border-top: 1px solid var(--dsu-border);
  }

  .dsu-feats,
  .dsu-plans {
    grid-template-columns: repeat(2, 1fr);
  }

  .dsu-support__side {
    border-left: 0;
    border-top: 1px solid var(--dsu-border);
  }
}

@media (max-width: 760px) {
  .dsu-flow,
  .models__list {
    grid-template-columns: 1fr;
  }

  .dsu-flow li::after {
    display: none;
  }

  .models__list li:nth-child(odd) {
    border-right: 0;
  }

  .dsu-get {
    grid-template-columns: 1fr;
    justify-items: start;
  }
}

@media (max-width: 640px) {
  .dsu-feats,
  .dsu-plans {
    grid-template-columns: 1fr;
  }

  .dsu-langs {
    grid-template-columns: repeat(2, 1fr);
  }

  .dsu-frame__bar span,
  .gallery__top em {
    display: none;
  }

  .dsu-strip {
    justify-content: flex-start;
  }
}