.download-hero {
  position: relative;
  padding-top: clamp(54px, 8vw, 96px);
  padding-bottom: clamp(42px, 7vw, 78px);
  overflow-x: clip;
  border-bottom: 1px solid var(--color-border);
}

.download-hero::before {
  content: "";
  position: absolute;
  top: -190px;
  right: -130px;
  width: 620px;
  height: 620px;
  border: 1px solid var(--color-accent-line);
  border-radius: 50%;
  background: radial-gradient(circle, var(--color-glow), var(--color-transparent) 66%);
  pointer-events: none;
}

.download-hero::after {
  content: "";
  position: absolute;
  right: 12%;
  bottom: 0;
  width: 34%;
  height: 1px;
  background: linear-gradient(90deg, var(--color-transparent), var(--color-warn), var(--color-transparent));
  opacity: 0.72;
  pointer-events: none;
}

.download-hero-grid {
  position: relative;
  display: grid;
  grid-template-columns: minmax(0, 1.35fr) minmax(300px, 0.65fr);
  align-items: center;
  gap: clamp(30px, 6vw, 84px);
}

.download-hero-copy {
  max-width: 820px;
}

.download-hero-copy h1 {
  max-width: 760px;
  margin-bottom: 24px;
}

.download-hero-copy .lead {
  margin-bottom: 24px;
}

.download-brief {
  position: relative;
  overflow: hidden;
  background:
    linear-gradient(145deg, var(--color-accent-soft), var(--color-transparent) 62%),
    var(--color-bg-panel);
}

.download-brief::before {
  content: "";
  position: absolute;
  top: 0;
  right: 34px;
  left: 34px;
  height: 2px;
  background: linear-gradient(90deg, var(--color-transparent), var(--color-accent), var(--color-transparent));
}

.download-brief-head {
  margin-bottom: 20px;
  display: flex;
  align-items: center;
  gap: 10px;
  color: var(--color-accent);
  font-family: var(--font-mono);
  font-size: 0.72rem;
  font-weight: 700;
  letter-spacing: 0.09em;
  text-transform: uppercase;
}

.download-brief-list {
  margin: 0;
  padding: 0;
  display: grid;
  gap: 11px;
  list-style: none;
}

.download-brief-list li {
  padding: 13px;
  display: grid;
  grid-template-columns: 34px minmax(0, 1fr);
  gap: 1px 10px;
  border: 1px solid var(--color-border);
  border-radius: var(--radius-sm);
  background: var(--color-bg-deep);
}

.download-brief-list li > span {
  grid-row: 1 / span 2;
  color: var(--color-warn);
  font-family: var(--font-mono);
  font-size: 0.68rem;
}

.download-brief-list strong {
  font-size: 0.86rem;
}

.download-brief-list small {
  color: var(--color-text-faint);
  font-size: 0.7rem;
  line-height: 1.5;
}

.platform-intro {
  margin-bottom: 28px;
  display: grid;
  grid-template-columns: minmax(220px, 0.55fr) minmax(0, 1fr);
  align-items: end;
  gap: 24px;
}

.platform-intro .badge {
  margin-bottom: 11px;
}

.platform-intro h2 {
  margin-bottom: 0;
  font-size: clamp(1.8rem, 3vw, 2.45rem);
}

.platform-intro p {
  margin-bottom: 0;
}

.client-card {
  display: flex;
  flex-direction: column;
}

.client-card-icon {
  width: 48px;
  height: 48px;
  flex-shrink: 0;
}

.client-summary {
  margin: 17px 0 0;
  flex: 1;
  font-size: 0.86rem;
  line-height: 1.72;
}

.client-card-actions .button {
  flex: 1 1 156px;
}

.client-card-archived {
  background:
    linear-gradient(135deg, var(--color-panel-muted), var(--color-transparent)),
    var(--color-bg-panel);
}

.client-site {
  margin: 15px 0 0;
  color: var(--color-text-muted);
  font-size: 0.84rem;
}

.client-site a {
  color: var(--color-accent);
  font-family: var(--font-mono);
  text-decoration: underline;
  text-decoration-color: var(--color-accent-line);
  text-underline-offset: 0.2em;
}

.download-grid-single {
  grid-template-columns: minmax(0, 720px);
}

.requirements-block {
  margin-top: 34px;
  padding-top: 28px;
  border-top: 1px solid var(--color-border);
}

.requirements-block h3 {
  margin-bottom: 17px;
}

.kernel-layout {
  display: grid;
  grid-template-columns: minmax(0, 0.72fr) minmax(520px, 1.28fr);
  align-items: start;
  gap: clamp(28px, 5vw, 68px);
}

.kernel-copy {
  position: sticky;
  top: 24px;
}

.kernel-table {
  padding: 16px;
}

.kernel-table .data-table {
  min-width: 600px;
}

.kernel-link {
  color: var(--color-accent);
  font-weight: 750;
  white-space: nowrap;
}

.kernel-link:hover {
  color: var(--color-success);
}

.kernel-notes {
  margin-top: 28px;
  display: grid;
  grid-template-columns: repeat(3, minmax(0, 1fr));
  gap: 14px;
}

.kernel-note {
  padding: 21px;
  display: grid;
  grid-template-columns: 34px minmax(0, 1fr);
  gap: 12px;
  border: 1px solid var(--color-border);
  border-radius: var(--radius-md);
  background: var(--color-bg-panel);
}

.kernel-note-index {
  color: var(--color-warn);
  font-family: var(--font-mono);
  font-size: 0.7rem;
  font-weight: 700;
}

.kernel-note h3 {
  margin-bottom: 8px;
  font-size: 1.08rem;
}

.kernel-note p {
  margin-bottom: 0;
  font-size: 0.82rem;
}

.selection-board {
  display: grid;
  grid-template-columns: minmax(220px, 0.72fr) minmax(0, 1.45fr) minmax(190px, 0.55fr);
  overflow: hidden;
  border: 1px solid var(--color-border-strong);
  border-radius: var(--radius-xl);
  background: var(--color-bg-panel);
  box-shadow: var(--shadow-panel);
}

.selection-board-index,
.selection-board-body,
.selection-board-rail {
  padding: clamp(24px, 4vw, 38px);
}

.selection-board-index {
  border-right: 1px solid var(--color-border);
  background: var(--color-bg-deep);
}

.selection-board-index h2 {
  font-size: clamp(1.8rem, 3vw, 2.55rem);
}

.selection-board-index p {
  margin-bottom: 0;
  font-size: 0.87rem;
}

.selection-board-body {
  display: grid;
  gap: 0;
}

.selection-row {
  padding: 18px 0;
  display: grid;
  grid-template-columns: 38px minmax(0, 1fr);
  gap: 13px;
  border-bottom: 1px solid var(--color-border);
}

.selection-row:first-child {
  padding-top: 0;
}

.selection-row:last-child {
  padding-bottom: 0;
  border-bottom: 0;
}

.selection-number {
  color: var(--color-accent);
  font-family: var(--font-mono);
  font-size: 0.7rem;
  font-weight: 700;
}

.selection-row h3 {
  margin-bottom: 7px;
  font-size: 1.05rem;
}

.selection-row p {
  margin-bottom: 0;
  font-size: 0.84rem;
}

.selection-board-rail {
  border-left: 1px solid var(--color-border);
  background: var(--color-bg-panel-2);
}

.selection-board-rail h3 {
  margin-bottom: 18px;
  font-size: 1rem;
}

.selection-board-rail a {
  min-height: 44px;
  padding: 10px 0;
  display: flex;
  align-items: center;
  border-bottom: 1px solid var(--color-border);
  color: var(--color-text-muted);
  font-size: 0.8rem;
  font-weight: 650;
}

.selection-board-rail a::after {
  content: "→";
  margin-left: auto;
  padding-left: 10px;
  flex-shrink: 0;
  color: var(--color-accent);
}

.selection-board-rail a:hover {
  color: var(--color-text);
}

#download-faq .callout a {
  color: var(--color-accent);
  text-decoration: underline;
  text-decoration-color: var(--color-accent-line);
  text-underline-offset: 0.2em;
}

@media (max-width: 1080px) {
  .download-hero-grid {
    grid-template-columns: minmax(0, 1fr) minmax(280px, 0.7fr);
  }

  .kernel-layout {
    grid-template-columns: minmax(0, 1fr);
  }

  .kernel-copy {
    position: static;
  }

  .selection-board {
    grid-template-columns: minmax(220px, 0.62fr) minmax(0, 1.38fr);
  }

  .selection-board-rail {
    grid-column: 1 / -1;
    display: grid;
    grid-template-columns: repeat(4, minmax(0, 1fr));
    gap: 0 16px;
    border-top: 1px solid var(--color-border);
    border-left: 0;
  }

  .selection-board-rail h3 {
    grid-column: 1 / -1;
  }
}

@media (max-width: 820px) {
  .download-hero-grid {
    grid-template-columns: minmax(0, 1fr);
  }

  .download-brief {
    max-width: 620px;
  }

  .platform-intro {
    grid-template-columns: minmax(0, 1fr);
    align-items: start;
    gap: 12px;
  }

  .kernel-notes {
    grid-template-columns: minmax(0, 1fr);
  }

  .selection-board {
    grid-template-columns: minmax(0, 1fr);
  }

  .selection-board-index {
    border-right: 0;
    border-bottom: 1px solid var(--color-border);
  }

  .selection-board-rail {
    grid-column: auto;
    grid-template-columns: repeat(2, minmax(0, 1fr));
  }
}

@media (max-width: 640px) {
  .download-hero {
    padding-top: 42px;
    padding-bottom: 42px;
  }

  .download-hero::before {
    top: -80px;
    right: -260px;
  }

  .download-brief-list li {
    grid-template-columns: 30px minmax(0, 1fr);
  }

  .tab-panel {
    padding: 20px;
  }

  .client-card-actions .button {
    flex-basis: 100%;
  }

  .kernel-table {
    padding: 10px;
  }

  .kernel-note {
    padding: 18px;
  }

  .selection-board {
    border-radius: var(--radius-lg);
  }

  .selection-board-rail {
    grid-template-columns: minmax(0, 1fr);
  }
}