:root {
  --bg: #f6f8fb;
  --ink: #18212a;
  --muted: #5d6b78;
  --panel: #ffffff;
  --line: #d8e0e8;
  --teal: #177e89;
  --teal-dark: #0e626b;
  --amber: #d9911b;
  --navy: #151c24;
  --green: #2c8a55;
  --shadow: 0 18px 48px rgba(18, 28, 38, 0.16);
}

* {
  box-sizing: border-box;
}

html {
  scroll-behavior: smooth;
}

body {
  margin: 0;
  background: var(--bg);
  color: var(--ink);
  font-family: "Segoe UI", Arial, sans-serif;
  line-height: 1.5;
}

a {
  color: inherit;
}

code {
  font-family: Consolas, "Courier New", monospace;
  font-size: 0.94em;
}

.site-header {
  position: sticky;
  top: 0;
  z-index: 20;
  display: flex;
  align-items: center;
  justify-content: space-between;
  min-height: 66px;
  padding: 0 32px;
  background: rgba(246, 248, 251, 0.92);
  border-bottom: 1px solid rgba(216, 224, 232, 0.86);
  backdrop-filter: blur(12px);
}

.brand {
  display: inline-flex;
  align-items: center;
  gap: 10px;
  color: var(--ink);
  font-size: 17px;
  font-weight: 750;
  text-decoration: none;
}

.brand img {
  width: 36px;
  height: 36px;
}

.nav-links {
  display: flex;
  align-items: center;
  justify-content: flex-end;
  flex-wrap: wrap;
  gap: 22px;
  color: var(--muted);
  font-size: 14px;
  font-weight: 650;
}

.nav-links a {
  text-decoration: none;
}

.nav-links a:hover {
  color: var(--teal-dark);
}

.hero {
  position: relative;
  min-height: calc(100vh - 66px);
  padding: 112px 36px 86px;
  overflow: hidden;
  background:
    linear-gradient(135deg, rgba(21, 28, 36, 0.94), rgba(18, 39, 45, 0.82)),
    url("assets/atlas_xsd_512.png") center right 8% / 380px no-repeat;
  color: #ffffff;
}

.hero::after {
  content: "";
  position: absolute;
  inset: auto 0 0;
  height: 118px;
  background: linear-gradient(180deg, rgba(246, 248, 251, 0), var(--bg));
  pointer-events: none;
}

.hero-mark {
  position: absolute;
  right: min(10vw, 120px);
  bottom: 76px;
  width: min(28vw, 340px);
  height: auto;
  opacity: 0.18;
  filter: saturate(0.85);
}

.schema-visual {
  position: absolute;
  inset: 0;
  opacity: 0.54;
  pointer-events: none;
}

.schema-node {
  position: absolute;
  min-width: 118px;
  height: 42px;
  padding: 10px 16px;
  border: 1px solid rgba(255, 255, 255, 0.24);
  border-radius: 8px;
  background: rgba(255, 255, 255, 0.11);
  color: #e8f7f7;
  font-size: 13px;
  font-weight: 700;
  text-align: center;
  box-shadow: 0 10px 34px rgba(0, 0, 0, 0.22);
}

.root-node {
  top: 26%;
  left: 50%;
  transform: translateX(-50%);
  border-color: rgba(142, 230, 216, 0.55);
}

.node-a {
  top: 44%;
  left: 24%;
}

.node-b {
  top: 51%;
  left: 50%;
  transform: translateX(-50%);
}

.node-c {
  top: 44%;
  right: 24%;
}

.schema-line {
  position: absolute;
  height: 1px;
  background: rgba(142, 230, 216, 0.36);
  transform-origin: left center;
}

.line-a {
  top: 39%;
  left: 39%;
  width: 18%;
  transform: rotate(145deg);
}

.line-b {
  top: 39%;
  left: 50%;
  width: 12%;
  transform: rotate(90deg);
}

.line-c {
  top: 39%;
  left: 56%;
  width: 18%;
  transform: rotate(35deg);
}

.hero-content {
  position: relative;
  z-index: 2;
  width: min(860px, 100%);
  margin: 0 auto;
  text-align: center;
}

.eyebrow,
.section-kicker {
  display: inline-block;
  color: var(--amber);
  font-size: 12px;
  font-weight: 800;
  letter-spacing: 0;
  text-transform: uppercase;
}

.hero h1 {
  margin: 10px 0 14px;
  color: #ffffff;
  font-size: clamp(46px, 9vw, 96px);
  line-height: 0.98;
  letter-spacing: 0;
}

.hero-copy {
  width: min(720px, 100%);
  margin: 0 auto;
  color: #d8e7ec;
  font-size: clamp(18px, 2.4vw, 24px);
}

.hero-actions {
  display: flex;
  flex-wrap: wrap;
  justify-content: center;
  gap: 12px;
  margin-top: 34px;
}

.button {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  min-height: 44px;
  padding: 11px 18px;
  border: 1px solid transparent;
  border-radius: 8px;
  font-size: 15px;
  font-weight: 750;
  text-decoration: none;
  cursor: pointer;
  transition: transform 160ms ease, background-color 160ms ease, border-color 160ms ease;
}

.button:hover {
  transform: translateY(-1px);
}

.button.primary {
  background: var(--teal);
  color: #ffffff;
}

.button.primary:hover {
  background: var(--teal-dark);
}

.button.secondary {
  border-color: rgba(255, 255, 255, 0.42);
  color: #ffffff;
}

.section {
  width: min(1120px, calc(100% - 40px));
  margin: 0 auto;
  padding: 74px 0;
}

.section-heading {
  max-width: 720px;
}

.section-heading h2,
.download-band h2 {
  margin: 8px 0 14px;
  color: var(--ink);
  font-size: clamp(28px, 4vw, 44px);
  line-height: 1.12;
  letter-spacing: 0;
}

.section-heading p,
.download-band p {
  margin: 0;
  color: var(--muted);
  font-size: 17px;
}

.feature-grid {
  display: grid;
  grid-template-columns: repeat(3, minmax(0, 1fr));
  gap: 18px;
  margin-top: 32px;
}

.info-grid {
  display: grid;
  grid-template-columns: repeat(3, minmax(0, 1fr));
  gap: 18px;
  margin-top: 28px;
}

.feature,
.info-block,
.resource-card,
.content-card,
.signup-form,
.download-panel {
  border: 1px solid var(--line);
  border-radius: 8px;
  background: var(--panel);
  box-shadow: 0 12px 32px rgba(33, 45, 57, 0.08);
}

.feature {
  padding: 24px;
}

.resource-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(170px, 1fr));
  gap: 14px;
  margin-top: 28px;
}

.resource-card {
  display: grid;
  gap: 8px;
  min-height: 126px;
  padding: 18px;
  color: var(--ink);
  text-decoration: none;
}

.resource-card:hover {
  border-color: rgba(23, 126, 137, 0.42);
  transform: translateY(-1px);
}

.resource-card span {
  color: var(--teal-dark);
  font-size: 12px;
  font-weight: 850;
  text-transform: uppercase;
}

.resource-card strong {
  font-size: 17px;
  line-height: 1.25;
}

.info-block {
  padding: 22px;
}

.info-block h3 {
  margin: 0 0 8px;
  color: var(--ink);
  font-size: 19px;
}

.info-block p {
  margin: 0;
  color: var(--muted);
}

.feature-icon {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  min-width: 48px;
  height: 32px;
  padding: 0 10px;
  border-radius: 6px;
  background: #e7f5f4;
  color: var(--teal-dark);
  font-size: 12px;
  font-weight: 850;
}

.feature h3 {
  margin: 18px 0 8px;
  color: var(--ink);
  font-size: 20px;
}

.feature p {
  margin: 0;
  color: var(--muted);
}

.split-section {
  display: grid;
  grid-template-columns: minmax(0, 0.9fr) minmax(360px, 1fr);
  align-items: start;
  gap: 38px;
}

.access-stack {
  display: grid;
  gap: 16px;
}

.signup-form {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 16px;
  padding: 24px;
}

.signup-form.is-hidden {
  display: none;
}

.form-intro,
.full-row {
  grid-column: 1 / -1;
}

.form-intro h3 {
  margin: 0 0 6px;
  color: var(--ink);
  font-size: 20px;
  line-height: 1.2;
}

.form-intro p {
  margin: 0;
  color: var(--muted);
  font-size: 14px;
}

.signup-form label {
  display: grid;
  gap: 6px;
  color: var(--ink);
  font-size: 14px;
  font-weight: 700;
}

.signup-form input,
.signup-form select {
  width: 100%;
  height: 44px;
  border: 1px solid #c8d3dd;
  border-radius: 6px;
  background: #ffffff;
  color: var(--ink);
  font: inherit;
  padding: 0 12px;
}

.signup-form input:focus,
.signup-form select:focus {
  border-color: var(--teal);
  outline: 3px solid rgba(23, 126, 137, 0.18);
}

.checkbox-row {
  grid-column: 1 / -1;
  display: flex !important;
  grid-template-columns: none !important;
  align-items: center;
  gap: 10px !important;
  color: var(--muted) !important;
  font-weight: 600 !important;
}

.checkbox-row input {
  width: 18px;
  height: 18px;
}

.signup-form button,
.form-note,
.form-status {
  grid-column: 1 / -1;
}

.signup-form button {
  border: 0;
}

.link-button {
  justify-self: start;
  width: auto;
  min-height: 0;
  padding: 0;
  border: 0;
  background: transparent;
  color: var(--teal-dark);
  font: inherit;
  font-size: 14px;
  font-weight: 750;
  text-align: left;
  text-decoration: underline;
  cursor: pointer;
}

.link-button:hover {
  color: var(--teal);
}

.signup-form button:disabled {
  background: #8996a3;
  cursor: wait;
  transform: none;
}

.form-note {
  margin: -4px 0 0;
  color: var(--muted);
  font-size: 13px;
  font-weight: 500;
}

.form-status {
  min-height: 22px;
  margin: 0;
  color: var(--green);
  font-size: 14px;
  font-weight: 700;
}

.form-status.is-error {
  color: #b42318;
}

.download-band {
  width: min(1120px, calc(100% - 40px));
  margin: 0 auto 54px;
  padding: 34px;
  border-radius: 8px;
  background: var(--navy);
  color: #ffffff;
  box-shadow: var(--shadow);
}

.download-band h2 {
  color: #ffffff;
}

.download-band p {
  color: #cbd7e2;
}

.download-panel {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 18px;
  margin: 28px 0 18px;
  padding: 20px;
  background: #ffffff;
}

.package-info {
  display: grid;
  gap: 4px;
  color: var(--ink);
}

.package-info strong {
  font-size: 18px;
}

.package-info span {
  color: var(--muted);
  font-size: 14px;
}

.download-button.is-disabled {
  background: #8996a3;
  cursor: not-allowed;
}

.security-note {
  border-top: 1px solid rgba(255, 255, 255, 0.18);
  padding-top: 16px;
  font-size: 14px !important;
}

.site-footer {
  display: flex;
  flex-wrap: wrap;
  justify-content: center;
  gap: 18px;
  padding: 28px 20px 36px;
  color: var(--muted);
  font-size: 14px;
}

.site-footer span {
  color: var(--ink);
  font-weight: 800;
}

.site-footer a {
  text-decoration: none;
}

.site-footer a:hover {
  color: var(--teal-dark);
}

.page-hero {
  position: relative;
  padding: 84px 36px 76px;
  overflow: hidden;
  background:
    linear-gradient(135deg, rgba(21, 28, 36, 0.96), rgba(18, 39, 45, 0.84)),
    url("assets/atlas_xsd_512.png") center right 8% / 280px no-repeat;
  color: #ffffff;
}

.page-hero-content {
  width: min(920px, 100%);
  margin: 0 auto;
}

.breadcrumb {
  margin: 0 0 28px;
  color: #cbd7e2;
  font-size: 14px;
  font-weight: 650;
}

.breadcrumb a {
  color: #ffffff;
  text-decoration: none;
}

.breadcrumb a:hover {
  text-decoration: underline;
}

.page-hero h1 {
  width: min(780px, 100%);
  margin: 10px 0 16px;
  color: #ffffff;
  font-size: clamp(38px, 6vw, 68px);
  line-height: 1.04;
  letter-spacing: 0;
}

.page-hero p {
  width: min(760px, 100%);
  margin: 0;
  color: #d8e7ec;
  font-size: clamp(17px, 2vw, 22px);
}

.page-content {
  width: min(980px, calc(100% - 40px));
  margin: 0 auto;
  padding: 62px 0;
  display: grid;
  gap: 52px;
}

.page-section h2 {
  margin: 0 0 14px;
  color: var(--ink);
  font-size: clamp(26px, 3vw, 36px);
  line-height: 1.16;
}

.page-section p {
  margin: 0 0 16px;
  color: var(--muted);
  font-size: 17px;
}

.page-section p:last-child {
  margin-bottom: 0;
}

.content-grid {
  display: grid;
  grid-template-columns: repeat(3, minmax(0, 1fr));
  gap: 18px;
  margin-top: 24px;
}

.content-card {
  padding: 22px;
}

.content-card h3 {
  margin: 0 0 8px;
  color: var(--ink);
  font-size: 19px;
}

.content-card p {
  margin: 0;
  color: var(--muted);
  font-size: 15px;
}

.release-panel {
  display: grid;
  border: 1px solid var(--line);
  border-radius: 8px;
  background: var(--panel);
  box-shadow: 0 12px 32px rgba(33, 45, 57, 0.08);
  overflow: hidden;
}

.release-row {
  display: grid;
  grid-template-columns: minmax(150px, 0.45fr) minmax(0, 1fr);
  gap: 18px;
  padding: 16px 20px;
  border-bottom: 1px solid var(--line);
}

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

.release-row span {
  color: var(--muted);
  font-weight: 700;
}

.release-row strong {
  color: var(--ink);
  overflow-wrap: anywhere;
}

.code-block {
  margin: 18px 0 0;
  padding: 16px;
  overflow-x: auto;
  border: 1px solid var(--line);
  border-radius: 8px;
  background: #111820;
  color: #e8f7f7;
  font-size: 14px;
}

.code-block code {
  font-family: Consolas, "Courier New", monospace;
}

.inline-button {
  margin-top: 4px;
  width: auto;
}

.plain-list {
  margin: 18px 0 0;
  padding-left: 22px;
  color: var(--muted);
  font-size: 17px;
}

.plain-list li {
  margin: 8px 0;
}

.cta-strip {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 22px;
  padding: 28px;
  border-radius: 8px;
  background: var(--navy);
  color: #ffffff;
}

.cta-strip h2 {
  margin: 0 0 6px;
  color: #ffffff;
  font-size: clamp(24px, 3vw, 32px);
}

.cta-strip p {
  margin: 0;
  color: #cbd7e2;
}

.faq-list {
  display: grid;
  gap: 12px;
}

.faq-list details {
  border: 1px solid var(--line);
  border-radius: 8px;
  background: var(--panel);
  padding: 18px 20px;
}

.faq-list summary {
  color: var(--ink);
  font-size: 17px;
  font-weight: 800;
  cursor: pointer;
}

.faq-list p {
  margin: 12px 0 0;
  color: var(--muted);
}

@media (max-width: 860px) {
  .site-header {
    align-items: flex-start;
    flex-direction: column;
    gap: 10px;
    padding: 14px 20px;
  }

  .nav-links {
    width: 100%;
    justify-content: flex-start;
    gap: 12px;
  }

  .hero {
    min-height: 82vh;
    padding: 78px 24px 72px;
    background:
      linear-gradient(135deg, rgba(21, 28, 36, 0.96), rgba(18, 39, 45, 0.88)),
      url("assets/atlas_xsd_512.png") center 68% / 250px no-repeat;
  }

  .hero-mark,
  .schema-visual {
    display: none;
  }

  .feature-grid,
  .info-grid,
  .resource-grid,
  .content-grid,
  .split-section {
    grid-template-columns: 1fr;
  }

  .signup-form {
    grid-template-columns: 1fr;
  }

  .download-panel {
    align-items: stretch;
    flex-direction: column;
  }

  .cta-strip {
    align-items: stretch;
    flex-direction: column;
  }

  .release-row {
    grid-template-columns: 1fr;
    gap: 4px;
  }

  .download-panel .button {
    width: 100%;
  }
}

@media (max-width: 520px) {
  .nav-links {
    font-size: 13px;
  }

  .hero-actions {
    align-items: stretch;
    flex-direction: column;
  }

  .button {
    width: 100%;
  }

  .download-band {
    padding: 24px;
  }
}