:root {
  --night: #07111f;
  --night-2: #0d1d31;
  --ink: #162033;
  --muted: #59697f;
  --soft: #eef3f8;
  --surface: #ffffff;
  --line: #d6e0ea;
  --blue: #005ea8;
  --blue-dark: #16456f;
  --red: #b6212f;
  --red-dark: #8e1823;
  --steel: #34465d;
  --shadow: 0 18px 45px rgba(11, 26, 44, 0.12);
  --radius: 8px;
  --max-width: 1180px;
}

* {
  box-sizing: border-box;
}

html {
  scroll-behavior: smooth;
}

body {
  margin: 0;
  background: #f5f8fb;
  color: var(--ink);
  font-family: Inter, ui-sans-serif, system-ui, -apple-system, BlinkMacSystemFont, "Segoe UI", sans-serif;
  line-height: 1.6;
}

a {
  color: inherit;
}

button,
input,
textarea,
select {
  font: inherit;
}

.sr-only {
  position: absolute;
  width: 1px;
  height: 1px;
  padding: 0;
  margin: -1px;
  overflow: hidden;
  clip: rect(0, 0, 0, 0);
  white-space: nowrap;
  border: 0;
}

.site-header {
  color: #f8fbff;
  background-color: var(--night);
  background-image:
    linear-gradient(rgba(255, 255, 255, 0.035) 1px, transparent 1px),
    linear-gradient(90deg, rgba(255, 255, 255, 0.035) 1px, transparent 1px),
    linear-gradient(135deg, #07111f 0%, #10243a 58%, #06101d 100%);
  background-size: 42px 42px, 42px 42px, auto;
}

.topbar {
  width: min(100% - 40px, var(--max-width));
  margin: 0 auto;
  min-height: 76px;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 24px;
  border-bottom: 1px solid rgba(255, 255, 255, 0.14);
}

.brand {
  display: inline-flex;
  align-items: center;
  gap: 12px;
  text-decoration: none;
  color: #ffffff;
  font-weight: 750;
}

.brand-mark {
  display: grid;
  width: 36px;
  height: 36px;
  place-items: center;
  border: 1px solid rgba(255, 255, 255, 0.28);
  border-left: 4px solid var(--red);
  color: #ffffff;
  font-size: 0.88rem;
  letter-spacing: 0.06em;
}

.brand-text {
  font-size: 0.98rem;
}

.nav-toggle {
  display: none;
  width: 44px;
  height: 44px;
  border: 1px solid rgba(255, 255, 255, 0.24);
  background: rgba(255, 255, 255, 0.08);
  color: #ffffff;
  align-items: center;
  justify-content: center;
  flex-direction: column;
  gap: 5px;
  cursor: pointer;
}

.nav-toggle-line {
  width: 18px;
  height: 2px;
  background: currentColor;
  display: block;
}

.nav-links {
  display: flex;
  align-items: center;
  gap: 22px;
}

.nav-links a {
  color: #dbe8f7;
  font-size: 0.92rem;
  text-decoration: none;
  transition: color 160ms ease;
}

.nav-links a:hover,
.nav-links a:focus-visible {
  color: #ffffff;
}

.hero {
  width: min(100% - 40px, var(--max-width));
  margin: 0 auto;
  display: grid;
  grid-template-columns: minmax(0, 1.05fr) minmax(280px, 0.45fr);
  gap: 56px;
  align-items: center;
  padding: 86px 0 92px;
}

.hero-copy h1 {
  max-width: 860px;
  margin: 0;
  font-family: Georgia, "Times New Roman", serif;
  font-size: clamp(2.55rem, 6vw, 5.7rem);
  line-height: 0.97;
  font-weight: 500;
  letter-spacing: 0;
}

.subtitle {
  max-width: 720px;
  margin: 26px 0 0;
  color: #d6e3f2;
  font-size: clamp(1.05rem, 2vw, 1.34rem);
  line-height: 1.55;
}

.section-code {
  margin: 0 0 16px;
  color: var(--red);
  font-size: 0.75rem;
  font-weight: 800;
  letter-spacing: 0.15em;
  text-transform: uppercase;
}

.hero .section-code {
  color: #ff6974;
}

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

.button {
  min-height: 46px;
  display: inline-flex;
  align-items: center;
  justify-content: center;
  padding: 0 18px;
  border: 1px solid transparent;
  border-radius: 4px;
  font-size: 0.94rem;
  font-weight: 750;
  text-decoration: none;
}

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

.button.secondary {
  background: rgba(255, 255, 255, 0.08);
  color: #ffffff;
  border-color: rgba(255, 255, 255, 0.28);
}

.hero-panel {
  background: rgba(255, 255, 255, 0.08);
  border: 1px solid rgba(255, 255, 255, 0.16);
  border-radius: var(--radius);
  box-shadow: 0 24px 70px rgba(0, 0, 0, 0.2);
  overflow: hidden;
}

.panel-line {
  padding: 22px 24px;
  border-bottom: 1px solid rgba(255, 255, 255, 0.13);
}

.panel-line:last-child {
  border-bottom: 0;
}

.panel-line span {
  display: block;
  margin-bottom: 8px;
  color: #9eb2c8;
  font-size: 0.76rem;
  font-weight: 750;
  text-transform: uppercase;
  letter-spacing: 0.1em;
}

.panel-line strong {
  display: block;
  color: #ffffff;
  font-size: 1.03rem;
  line-height: 1.35;
}

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

.section-heading {
  max-width: 790px;
  margin-bottom: 30px;
}

.section-heading h2 {
  margin: 0;
  color: var(--ink);
  font-family: Georgia, "Times New Roman", serif;
  font-size: clamp(2rem, 4vw, 3.45rem);
  line-height: 1.06;
  font-weight: 500;
  letter-spacing: 0;
}

.split-heading {
  max-width: none;
  display: flex;
  justify-content: space-between;
  gap: 28px;
  align-items: end;
}

.split-heading > div:first-child {
  max-width: 760px;
}

.intro-grid {
  display: grid;
  grid-template-columns: minmax(0, 1fr) 360px;
  gap: 28px;
  align-items: stretch;
}

.text-block,
.note-card,
.access-card,
.use-case-card,
.workflow-card,
.ai-card,
.dataset-card {
  background: var(--surface);
  border: 1px solid var(--line);
  border-radius: var(--radius);
  box-shadow: 0 8px 28px rgba(21, 40, 64, 0.06);
}

.text-block {
  padding: 34px;
}

.text-block p {
  margin: 0;
  max-width: 76ch;
  color: var(--steel);
  font-size: 1.06rem;
}

.text-block p + p {
  margin-top: 18px;
}

.note-card {
  padding: 28px;
  border-top: 4px solid var(--red);
}

.note-card h3,
.access-card h3,
.use-case-card h3,
.workflow-card h3,
.ai-card h3,
.dataset-card h3 {
  margin: 0;
  color: var(--ink);
  line-height: 1.18;
}

.note-card p,
.access-card p,
.use-case-card p,
.workflow-card p,
.ai-card p,
.dataset-card p,
.dataset-card li {
  color: var(--muted);
}

.filter-controls {
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
  justify-content: flex-end;
}

.filter-button {
  min-height: 38px;
  padding: 0 13px;
  border: 1px solid var(--line);
  border-radius: 4px;
  background: #ffffff;
  color: var(--steel);
  font-size: 0.88rem;
  font-weight: 750;
  cursor: pointer;
}

.filter-button:hover,
.filter-button:focus-visible,
.filter-button.active {
  border-color: var(--blue);
  background: var(--blue);
  color: #ffffff;
}

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

.dataset-card {
  display: flex;
  flex-direction: column;
  min-height: 100%;
  padding: 24px;
  border-top: 4px solid var(--blue);
}

.dataset-card[data-difficulty="Intermediate"] {
  border-top-color: var(--red);
}

.dataset-card[data-difficulty="Advanced"] {
  border-top-color: #536477;
}

.dataset-card h3 {
  font-size: 1.3rem;
}

.dataset-meta {
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
  margin: 14px 0 0;
}

.tag {
  display: inline-flex;
  align-items: center;
  min-height: 28px;
  padding: 0 9px;
  border: 1px solid #cdd8e4;
  border-radius: 4px;
  color: var(--blue-dark);
  background: #f7fbff;
  font-size: 0.76rem;
  font-weight: 800;
  text-transform: uppercase;
  letter-spacing: 0.06em;
}

.dataset-card dl {
  margin: 22px 0 0;
}

.dataset-card dt {
  margin-top: 18px;
  color: var(--ink);
  font-size: 0.74rem;
  font-weight: 850;
  letter-spacing: 0.1em;
  text-transform: uppercase;
}

.dataset-card dd {
  margin: 6px 0 0;
  color: var(--muted);
}

.dataset-card a {
  color: var(--blue);
  font-weight: 760;
  text-decoration-thickness: 0.08em;
  text-underline-offset: 0.16em;
}

.sample-workflow {
  margin-top: auto;
  padding-top: 18px;
}

.sample-workflow h4 {
  margin: 0 0 8px;
  color: var(--ink);
  font-size: 0.78rem;
  font-weight: 850;
  letter-spacing: 0.1em;
  text-transform: uppercase;
}

.sample-workflow p {
  margin: 0;
}

.loading-message,
.error-message {
  grid-column: 1 / -1;
  margin: 0;
  padding: 22px;
  background: #ffffff;
  border: 1px solid var(--line);
  border-radius: var(--radius);
  color: var(--steel);
}

.access-section,
.ai-section {
  width: 100%;
  max-width: none;
  background: #ffffff;
  border-top: 1px solid var(--line);
  border-bottom: 1px solid var(--line);
}

.access-section > *,
.ai-section > * {
  width: min(100% - 40px, var(--max-width));
  margin-left: auto;
  margin-right: auto;
}

.access-grid {
  display: grid;
  grid-template-columns: repeat(4, minmax(0, 1fr));
  gap: 16px;
}

.access-card {
  padding: 24px;
}

.step-number {
  display: grid;
  width: 34px;
  height: 34px;
  place-items: center;
  margin-bottom: 18px;
  background: var(--night);
  color: #ffffff;
  font-weight: 800;
  border-radius: 50%;
}

.access-card h3 {
  font-size: 1.1rem;
}

.access-card p {
  margin: 12px 0 0;
}

.architecture-section {
  padding-top: 84px;
}

.pipeline {
  display: grid;
  grid-template-columns:
    minmax(112px, 1fr) 24px minmax(112px, 1fr) 24px minmax(112px, 1fr) 24px
    minmax(150px, 1.25fr) 24px minmax(112px, 1fr) 24px minmax(112px, 1fr);
  gap: 10px;
  align-items: stretch;
  position: relative;
}

.pipeline-step {
  min-height: 86px;
  display: grid;
  place-items: center;
  padding: 14px;
  border: 1px solid var(--line);
  border-top: 4px solid var(--blue);
  border-radius: var(--radius);
  background: #ffffff;
  color: var(--ink);
  box-shadow: 0 8px 25px rgba(12, 29, 49, 0.06);
  text-align: center;
  font-weight: 800;
  line-height: 1.25;
}

.pipeline-step.decision {
  border-top-color: var(--red);
  color: var(--red-dark);
}

.pipeline-arrow {
  display: grid;
  place-items: center;
  color: var(--blue-dark);
  font-size: 1.18rem;
  font-weight: 850;
}

.use-case-grid {
  display: grid;
  grid-template-columns: repeat(3, minmax(0, 1fr));
  gap: 16px;
}

.use-case-card,
.workflow-card,
.ai-card {
  padding: 24px;
}

.use-case-card h3,
.workflow-card h3,
.ai-card h3 {
  font-size: 1.16rem;
}

.use-case-card p,
.workflow-card p,
.ai-card p {
  margin: 12px 0 0;
}

.workflow-layout {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 18px;
}

.workflow-card {
  border-left: 4px solid var(--blue);
}

.ai-grid {
  display: grid;
  grid-template-columns: repeat(3, minmax(0, 1fr));
  gap: 16px;
}

.ai-card {
  background: #f9fbfd;
}

.next-section {
  padding-bottom: 92px;
}

.next-list {
  margin: 0;
  padding: 0;
  list-style: none;
  counter-reset: next-step;
  display: grid;
  gap: 12px;
}

.next-list li {
  counter-increment: next-step;
  position: relative;
  padding: 22px 24px 22px 72px;
  background: #ffffff;
  border: 1px solid var(--line);
  border-radius: var(--radius);
  color: var(--muted);
  box-shadow: 0 8px 24px rgba(21, 40, 64, 0.05);
}

.next-list li::before {
  content: counter(next-step);
  position: absolute;
  left: 22px;
  top: 20px;
  width: 32px;
  height: 32px;
  display: grid;
  place-items: center;
  background: var(--red);
  color: #ffffff;
  border-radius: 50%;
  font-weight: 850;
}

.next-list strong {
  color: var(--ink);
}

.site-footer {
  padding: 32px 20px 38px;
  background: var(--night);
  color: #dce8f6;
  text-align: center;
}

.site-footer p {
  margin: 0;
}

.site-footer a {
  color: #ffffff;
  font-weight: 760;
}

.footer-small {
  margin-top: 8px !important;
  color: #9eb2c8;
  font-size: 0.88rem;
}

@media (max-width: 980px) {
  .hero,
  .intro-grid,
  .split-heading {
    grid-template-columns: 1fr;
  }

  .hero {
    gap: 34px;
  }

  .split-heading {
    display: block;
  }

  .filter-controls {
    justify-content: flex-start;
    margin-top: 22px;
  }

  .dataset-grid,
  .access-grid,
  .use-case-grid,
  .ai-grid {
    grid-template-columns: repeat(2, minmax(0, 1fr));
  }

  .pipeline {
    grid-template-columns: 1fr;
    gap: 0;
  }

  .pipeline-step {
    min-height: auto;
    padding: 18px;
  }

  .pipeline-arrow {
    min-height: 34px;
    color: var(--muted);
    transform: rotate(90deg);
    font-size: 1.2rem;
  }
}

@media (max-width: 720px) {
  .topbar {
    width: min(100% - 28px, var(--max-width));
    min-height: 68px;
  }

  .brand-text {
    max-width: 190px;
    line-height: 1.2;
  }

  .nav-toggle {
    display: inline-flex;
  }

  .nav-links {
    position: absolute;
    top: 68px;
    left: 14px;
    right: 14px;
    display: none;
    flex-direction: column;
    align-items: stretch;
    gap: 0;
    padding: 8px;
    background: #0a1727;
    border: 1px solid rgba(255, 255, 255, 0.18);
    box-shadow: 0 16px 35px rgba(0, 0, 0, 0.24);
    z-index: 10;
  }

  .nav-links.open {
    display: flex;
  }

  .nav-links a {
    padding: 13px 12px;
  }

  .hero,
  .section,
  .access-section > *,
  .ai-section > * {
    width: min(100% - 28px, var(--max-width));
  }

  .hero {
    padding: 56px 0 64px;
  }

  .section {
    padding: 52px 0;
  }

  .dataset-grid,
  .access-grid,
  .use-case-grid,
  .workflow-layout,
  .ai-grid {
    grid-template-columns: 1fr;
  }

  .text-block,
  .note-card,
  .dataset-card,
  .access-card,
  .use-case-card,
  .workflow-card,
  .ai-card {
    padding: 22px;
  }

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

  .button {
    width: 100%;
  }

  .next-list li {
    padding: 20px 20px 20px 64px;
  }
}