:root {
  --text: #172033;
  --muted: #667085;
  --subtle: #98a2b3;
  --border: #e4e7ec;
  --surface: #ffffff;
  --surface-soft: #f7f8fa;
  --surface-blue: #f3f6ff;
  --primary: #3157d5;
  --primary-dark: #2545ad;
  --success: #18794e;
  --warning-bg: #fff8eb;
  --warning-text: #7a5a18;
  --dark: #172033;
  --max: 1200px;
  --pad: clamp(24px, 4vw, 72px);
  --font-body: -apple-system, BlinkMacSystemFont, "Segoe UI", "PingFang SC",
    "Hiragino Sans GB", "Microsoft YaHei", "Noto Sans SC", "Noto Sans CJK SC",
    "Source Han Sans SC", sans-serif;
  --font-display: var(--font-body);
  --header-h: 72px;
}

*,
*::before,
*::after {
  box-sizing: border-box;
}

html {
  scroll-behavior: smooth;
  scroll-padding-top: calc(var(--header-h) + 12px);
}

body {
  margin: 0;
  min-width: 320px;
  color: var(--text);
  background: var(--surface);
  font-family: var(--font-body);
  font-size: 16px;
  line-height: 1.65;
  -webkit-font-smoothing: antialiased;
  text-rendering: optimizeLegibility;
}

img,
svg {
  max-width: 100%;
  display: block;
}

a {
  color: var(--primary);
}

a:visited {
  color: #5b45a6;
}

button,
a {
  -webkit-tap-highlight-color: transparent;
}

button {
  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;
}

.skip-link {
  position: fixed;
  z-index: 200;
  top: 12px;
  left: 12px;
  padding: 10px 14px;
  color: var(--surface);
  background: var(--dark);
  transform: translateY(-160%);
}

.skip-link:focus {
  transform: translateY(0);
}

.section-shell,
.nav-shell,
.hero-shell {
  width: min(var(--max), calc(100% - (var(--pad) * 2)));
  margin-inline: auto;
}

/* Header */
.site-header {
  position: sticky;
  z-index: 100;
  top: 0;
  height: var(--header-h);
  background: rgba(255, 255, 255, 0.96);
  border-bottom: 1px solid var(--border);
  backdrop-filter: blur(14px);
}

.nav-shell {
  height: 100%;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 24px;
}

.brand {
  min-height: 44px;
  display: inline-flex;
  align-items: center;
  gap: 10px;
  color: var(--text);
  font-weight: 700;
  letter-spacing: -0.02em;
  text-decoration: none;
  flex: 0 0 auto;
}

.brand:visited {
  color: var(--text);
}

.brand-mark {
  width: 30px;
  height: 30px;
  display: grid;
  place-items: center;
  color: #fff;
  background: var(--primary);
  border-radius: 7px;
  font-size: 16px;
  font-weight: 700;
}

.site-nav {
  display: flex;
  align-items: center;
  justify-content: flex-end;
  flex-wrap: wrap;
  gap: 8px 22px;
}

.site-nav a {
  min-height: 40px;
  display: inline-flex;
  align-items: center;
  color: #475467;
  font-size: 14px;
  font-weight: 500;
  text-decoration: none;
}

.site-nav a:visited {
  color: #475467;
}

.site-nav a:hover,
.site-nav a:focus-visible {
  color: var(--primary);
}

.site-nav .nav-cta {
  min-height: 40px;
  padding: 0 16px;
  color: #fff;
  background: var(--text);
  border-radius: 8px;
}

.site-nav .nav-cta:visited {
  color: #fff;
}

.site-nav .nav-cta:hover {
  color: #fff;
  background: #2a3448;
}

.nav-toggle {
  display: none;
}

/* Hero — desktop-first two column */
.hero {
  position: relative;
  padding: clamp(56px, 7vw, 104px) 0 clamp(64px, 8vw, 112px);
  overflow: hidden;
  background:
    radial-gradient(circle at 86% 8%, rgba(49, 87, 213, 0.1), transparent 34%),
    linear-gradient(180deg, #ffffff 0%, #f8faff 100%);
}

.hero-shell {
  display: grid;
  grid-template-columns: minmax(0, 1.2fr) minmax(420px, 0.95fr);
  gap: clamp(40px, 5vw, 72px);
  align-items: center;
}

.hero-copy {
  min-width: 0;
  max-width: 640px;
}

.kicker {
  margin: 0 0 16px;
  color: var(--primary);
  font-size: 13px;
  font-weight: 600;
  letter-spacing: 0.04em;
}

h1,
h2,
h3,
p {
  text-wrap: pretty;
}

h1,
h2,
h3 {
  font-family: var(--font-display);
  color: var(--text);
}

h1 {
  margin: 0;
  font-size: clamp(36px, 3.2vw + 0.6rem, 54px);
  font-weight: 700;
  letter-spacing: -0.035em;
  line-height: 1.18;
}

.hero-lead {
  max-width: 36em;
  margin: 22px 0 0;
  color: var(--muted);
  font-size: clamp(16px, 1.05vw + 0.55rem, 18px);
  line-height: 1.75;
}

.hero-actions {
  margin-top: 28px;
  display: flex;
  flex-wrap: wrap;
  gap: 12px;
}

.button {
  min-height: 48px;
  padding: 0 20px;
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 7px;
  border-radius: 9px;
  font-size: 15px;
  font-weight: 600;
  text-decoration: none;
  transition: background-color 160ms ease, border-color 160ms ease, transform 160ms ease;
}

.button:visited {
  color: inherit;
}

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

.button-primary {
  color: #fff;
  background: var(--primary);
  border: 1px solid var(--primary);
}

.button-primary:visited {
  color: #fff;
}

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

.button-secondary {
  color: var(--text);
  background: #fff;
  border: 1px solid #d0d5dd;
}

.button-secondary:visited {
  color: var(--text);
}

.button-secondary:hover {
  border-color: #98a2b3;
}

.stage-line {
  margin: 22px 0 0;
  display: flex;
  align-items: flex-start;
  gap: 9px;
  color: var(--muted);
  font-size: 14px;
  line-height: 1.5;
}

.stage-line span {
  width: 8px;
  height: 8px;
  margin-top: 0.45em;
  flex: 0 0 auto;
  border-radius: 50%;
  background: #d79b2b;
}

/* Product preview card */
.product-preview {
  width: 100%;
  max-width: 560px;
  justify-self: end;
  overflow: hidden;
  background: var(--surface);
  border: 1px solid #d9deea;
  border-radius: 14px;
  box-shadow: 0 20px 48px rgba(23, 32, 51, 0.1);
}

.preview-bar {
  min-height: 52px;
  padding: 0 18px;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 12px;
  border-bottom: 1px solid var(--border);
  font-size: 12px;
}

.preview-brand {
  display: flex;
  align-items: center;
  gap: 9px;
  font-weight: 600;
}

.preview-brand i {
  width: 23px;
  height: 23px;
  display: grid;
  place-items: center;
  color: #fff;
  background: var(--primary);
  border-radius: 5px;
  font-style: normal;
}

.preview-status {
  display: flex;
  align-items: center;
  gap: 7px;
  color: var(--success);
  white-space: nowrap;
}

.preview-status i {
  width: 7px;
  height: 7px;
  border-radius: 50%;
  background: #22a06b;
}

.preview-main {
  display: grid;
  grid-template-columns: 48px minmax(0, 1fr);
  min-height: 420px;
}

.preview-sidebar {
  padding-top: 20px;
  display: flex;
  align-items: center;
  flex-direction: column;
  gap: 14px;
  background: #f8f9fb;
  border-right: 1px solid var(--border);
}

.preview-sidebar span {
  width: 18px;
  height: 18px;
  border: 1px solid #d0d5dd;
  border-radius: 4px;
}

.preview-sidebar .active {
  background: var(--surface-blue);
  border-color: #9bb0f4;
}

.preview-content {
  min-width: 0;
  padding: 22px 24px 8px;
}

.preview-title {
  padding-bottom: 18px;
  display: flex;
  align-items: flex-start;
  justify-content: space-between;
  gap: 12px;
  border-bottom: 1px solid var(--border);
}

.preview-title small,
.flow-list small {
  display: block;
  color: var(--subtle);
  font-size: 11px;
}

.preview-title strong {
  display: block;
  margin-top: 4px;
  font-size: 16px;
}

.preview-title em {
  padding: 4px 9px;
  color: var(--primary);
  background: var(--surface-blue);
  border-radius: 6px;
  font-size: 11px;
  font-style: normal;
  flex: 0 0 auto;
}

.flow-list article {
  min-height: 78px;
  padding: 14px 0;
  display: grid;
  grid-template-columns: 34px minmax(0, 1fr) auto;
  gap: 12px;
  align-items: center;
  border-bottom: 1px solid #edf0f4;
}

.flow-list article:last-child {
  border-bottom: 0;
}

.flow-avatar {
  width: 34px;
  height: 34px;
  display: grid;
  place-items: center;
  color: #475467;
  background: #eef1f5;
  border-radius: 50%;
  font-size: 12px;
  font-weight: 700;
}

.flow-avatar-blue {
  color: var(--primary);
  background: #e9efff;
}

.flow-avatar-human {
  color: var(--success);
  background: #e8f6ef;
}

.flow-list strong {
  display: block;
  margin-top: 2px;
  font-size: 13px;
}

.flow-list p {
  margin: 1px 0 0;
  color: var(--muted);
  font-size: 12px;
}

.flow-list em {
  color: var(--subtle);
  font-size: 11px;
  font-style: normal;
  white-space: nowrap;
}

.flow-list .done {
  color: var(--success);
}

.flow-list .running {
  color: var(--primary);
}

/* Sections */
.section {
  padding: clamp(64px, 8vw, 104px) 0;
}

.section-white {
  background: var(--surface);
}

.section-soft {
  background: var(--surface-soft);
}

.intro-grid,
.case-grid,
.aws-grid,
.program-grid,
.final-cta .section-shell {
  display: grid;
  grid-template-columns: minmax(0, 0.95fr) minmax(0, 1.05fr);
  gap: clamp(36px, 5vw, 80px);
  align-items: start;
}

h2 {
  max-width: 18em;
  margin: 0;
  font-size: clamp(30px, 2.4vw + 0.7rem, 44px);
  font-weight: 700;
  letter-spacing: -0.03em;
  line-height: 1.22;
}

.section-lead,
.section-heading > p:last-child,
.case-copy > p,
.aws-copy > p {
  margin: 0;
  color: var(--muted);
  font-size: 17px;
  line-height: 1.75;
}

.intro-grid .section-lead {
  padding-top: 28px;
}

.problem-grid {
  margin-top: 56px;
  display: grid;
  grid-template-columns: repeat(3, minmax(0, 1fr));
  gap: 0;
  border-top: 1px solid var(--border);
}

.problem-grid article {
  padding: 28px 28px 0 0;
  border-right: 1px solid var(--border);
}

.problem-grid article + article {
  padding-left: 28px;
}

.problem-grid article:last-child {
  border-right: 0;
  padding-right: 0;
}

.problem-grid span {
  color: var(--primary);
  font-size: 12px;
  font-weight: 600;
}

.problem-grid h3 {
  margin: 16px 0 10px;
  font-size: 20px;
  letter-spacing: -0.02em;
}

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

.section-heading {
  max-width: 44rem;
  margin-bottom: 44px;
}

.section-heading > p:last-child {
  margin-top: 16px;
}

.steps {
  margin: 0;
  padding: 0;
  display: grid;
  grid-template-columns: repeat(5, minmax(0, 1fr));
  gap: 12px 16px;
  list-style: none;
  border-top: 1px solid #d9dde5;
}

.steps li {
  position: relative;
  min-width: 0;
  padding: 28px 12px 0 0;
}

.steps li::after {
  content: "";
  position: absolute;
  top: 46px;
  left: 40px;
  right: 0;
  height: 1px;
  background: #d9dde5;
}

.steps li:last-child::after {
  display: none;
}

.steps li > span {
  position: relative;
  z-index: 1;
  width: 36px;
  height: 36px;
  display: grid;
  place-items: center;
  color: var(--primary);
  background: #fff;
  border: 1px solid #aebceb;
  border-radius: 50%;
  font-size: 13px;
  font-weight: 700;
}

.steps strong {
  display: block;
  margin-top: 20px;
  font-size: 16px;
}

.steps p {
  margin: 6px 0 0;
  color: var(--muted);
  font-size: 14px;
  line-height: 1.55;
}

.case-copy > p {
  margin-top: 18px;
}

.case-note {
  margin-top: 28px;
  padding: 16px 18px;
  display: flex;
  gap: 16px;
  align-items: flex-start;
  background: var(--warning-bg);
  border-radius: 10px;
  color: var(--warning-text);
  font-size: 14px;
  line-height: 1.55;
}

.case-note strong {
  white-space: nowrap;
}

.case-detail {
  overflow: hidden;
  border: 1px solid var(--border);
  border-radius: 12px;
  background: #fff;
}

.case-stat {
  padding: 24px 28px;
  display: flex;
  align-items: baseline;
  flex-wrap: wrap;
  gap: 12px 16px;
  background: var(--surface-blue);
  border-bottom: 1px solid #d9e1fb;
}

.case-stat strong {
  color: var(--primary);
  font-size: clamp(48px, 5vw, 62px);
  line-height: 1;
  letter-spacing: -0.05em;
}

.case-stat span {
  color: #53627a;
  font-size: 14px;
}

.role-list {
  margin: 0;
  padding: 0 28px;
}

.role-list div {
  min-height: 62px;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 16px;
  border-bottom: 1px solid var(--border);
}

.role-list div:last-child {
  border-bottom: 0;
}

.role-list dt {
  color: var(--muted);
  font-size: 14px;
}

.role-list dd {
  margin: 0;
  font-size: 14px;
  font-weight: 600;
  text-align: right;
}

.artifact-line {
  margin-top: 44px;
  min-height: 64px;
  padding: 16px 24px;
  display: flex;
  align-items: center;
  justify-content: space-between;
  flex-wrap: wrap;
  gap: 10px 18px;
  color: #475467;
  background: #fafbfc;
  border: 1px solid var(--border);
  border-radius: 10px;
  font-size: 14px;
}

.artifact-line i {
  color: var(--subtle);
  font-style: normal;
}

.aws-copy {
  position: sticky;
  top: calc(var(--header-h) + 24px);
}

.aws-copy > p {
  margin-top: 18px;
}

.aws-list {
  border-top: 1px solid #d9dde5;
}

.aws-list article {
  padding: 28px 0;
  display: grid;
  grid-template-columns: 44px minmax(0, 1fr);
  gap: 16px;
  border-bottom: 1px solid #d9dde5;
}

.aws-list article > span {
  width: 32px;
  height: 32px;
  display: grid;
  place-items: center;
  color: var(--primary);
  background: #fff;
  border: 1px solid #c9d2ee;
  border-radius: 8px;
  font-size: 12px;
  font-weight: 600;
}

.aws-list h3 {
  margin: 2px 0 8px;
  font-size: 19px;
  letter-spacing: -0.02em;
}

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

.aws-list a {
  min-height: 40px;
  margin-top: 8px;
  display: inline-flex;
  align-items: center;
  font-size: 13px;
  text-underline-offset: 3px;
}

.program-section {
  background: var(--surface);
}

.program-grid ul {
  margin: 0;
  padding: 0;
  list-style: none;
  border-top: 1px solid var(--border);
}

.program-grid li {
  padding: 18px 0;
  display: grid;
  grid-template-columns: 88px minmax(0, 1fr);
  gap: 20px;
  border-bottom: 1px solid var(--border);
}

.program-grid strong {
  font-size: 15px;
}

.program-grid span {
  color: var(--muted);
}

.final-cta {
  padding: clamp(64px, 7vw, 96px) 0;
  color: #fff;
  background: var(--dark);
}

.final-cta .kicker {
  color: #a9bcff;
}

.final-cta h2 {
  color: #fff;
}

.final-cta .section-shell > div:last-child {
  padding-top: 24px;
}

.final-cta p {
  max-width: 36em;
  margin: 0 0 24px;
  color: #cbd1dc;
  font-size: 17px;
}

.button-light {
  color: var(--text);
  background: #fff;
  border: 1px solid #fff;
}

.button-light:visited {
  color: var(--text);
}

.site-footer {
  padding: 28px 0;
  background: #fff;
  border-top: 1px solid var(--border);
}

.site-footer .section-shell {
  min-height: 52px;
  display: grid;
  grid-template-columns: minmax(0, 1fr) minmax(0, 1.4fr) minmax(0, 1fr);
  align-items: center;
  gap: 16px;
}

.site-footer p {
  margin: 0;
  color: var(--muted);
  font-size: 12px;
  text-align: center;
}

.site-footer p:last-child {
  text-align: right;
}

a:focus-visible,
button:focus-visible {
  outline: 3px solid rgba(49, 87, 213, 0.28);
  outline-offset: 3px;
}

/* Large desktop polish */
@media (min-width: 1280px) {
  .hero-shell {
    grid-template-columns: minmax(0, 1.25fr) minmax(480px, 0.9fr);
    gap: 80px;
  }

  .product-preview {
    max-width: 540px;
  }

  .hero-lead {
    font-size: 18px;
  }
}

/* Tablet / narrow desktop: stack hero, keep nav */
@media (max-width: 1100px) {
  .hero-shell {
    grid-template-columns: 1fr;
    gap: 40px;
  }

  .hero-copy {
    max-width: 720px;
  }

  .product-preview {
    max-width: 680px;
    justify-self: start;
  }

  .intro-grid,
  .case-grid,
  .aws-grid,
  .program-grid,
  .final-cta .section-shell {
    grid-template-columns: 1fr;
    gap: 28px;
  }

  .intro-grid .section-lead {
    padding-top: 0;
  }

  .steps {
    grid-template-columns: repeat(3, minmax(0, 1fr));
  }

  .steps li::after {
    display: none;
  }

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

  .problem-grid article,
  .problem-grid article + article {
    padding: 24px 0;
    border-right: 0;
    border-bottom: 1px solid var(--border);
  }

  .problem-grid article:last-child {
    border-bottom: 0;
  }

  .aws-copy {
    position: static;
  }

  .final-cta .section-shell > div:last-child {
    padding-top: 0;
  }
}

@media (max-width: 900px) {
  .steps {
    grid-template-columns: repeat(2, minmax(0, 1fr));
  }

  .site-nav {
    gap: 6px 16px;
  }
}

/* Mobile */
@media (max-width: 720px) {
  :root {
    --header-h: 64px;
    --pad: 20px;
  }

  .site-header {
    height: var(--header-h);
  }

  .nav-toggle {
    width: 44px;
    height: 44px;
    display: grid;
    place-content: center;
    gap: 6px;
    color: var(--text);
    background: transparent;
    border: 0;
    cursor: pointer;
  }

  .nav-toggle > span:not(.sr-only) {
    width: 20px;
    height: 2px;
    background: currentColor;
    border-radius: 2px;
  }

  .site-nav {
    position: absolute;
    top: var(--header-h);
    left: 0;
    right: 0;
    padding: 12px var(--pad) 20px;
    display: none;
    flex-direction: column;
    align-items: stretch;
    flex-wrap: nowrap;
    gap: 0;
    background: #fff;
    border-bottom: 1px solid var(--border);
    box-shadow: 0 12px 24px rgba(23, 32, 51, 0.08);
  }

  .site-nav.is-open {
    display: flex;
  }

  .site-nav a {
    min-height: 48px;
    border-bottom: 1px solid #edf0f4;
  }

  .site-nav .nav-cta {
    margin-top: 12px;
    justify-content: center;
    border-bottom: 0;
  }

  .hero {
    padding-top: 48px;
  }

  h1 {
    font-size: clamp(32px, 9vw, 42px);
  }

  h2 {
    font-size: clamp(28px, 7vw, 36px);
  }

  .hero-lead {
    font-size: 16px;
  }

  .preview-main {
    grid-template-columns: 1fr;
    min-height: auto;
  }

  .preview-sidebar {
    display: none;
  }

  .preview-content {
    padding: 16px 18px 4px;
  }

  .flow-list article {
    grid-template-columns: 34px minmax(0, 1fr);
  }

  .flow-list em {
    grid-column: 2;
  }

  .steps {
    grid-template-columns: 1fr;
    border-top: 0;
    gap: 0;
  }

  .steps li {
    min-height: 88px;
    padding: 0 0 22px 56px;
  }

  .steps li > span {
    position: absolute;
    top: 0;
    left: 0;
  }

  .steps strong {
    margin-top: 0;
  }

  .case-note {
    flex-direction: column;
    gap: 4px;
  }

  .case-note strong {
    white-space: normal;
  }

  .artifact-line {
    padding: 16px 18px;
    justify-content: flex-start;
  }

  .program-grid li {
    grid-template-columns: 64px minmax(0, 1fr);
    gap: 12px;
  }

  .site-footer .section-shell {
    grid-template-columns: 1fr;
    gap: 12px;
  }

  .site-footer p,
  .site-footer p:last-child {
    text-align: left;
  }
}

@media (prefers-reduced-motion: reduce) {
  html {
    scroll-behavior: auto;
  }

  *,
  *::before,
  *::after {
    animation-duration: 0.01ms !important;
    transition-duration: 0.01ms !important;
  }
}