:root {
  --canvas: #f4f2ec;
  --white: #ffffff;
  --ink: #161719;
  --blue: #173fbe;
  --blue-deep: #11339f;
  --muted: #6d7078;
  --hairline: #d9d9d2;
  --header-height: 76px;
  --container: 1360px;
  --gutter: clamp(20px, 4vw, 72px);
  --section-space: clamp(78px, 9vw, 132px);
  --font-sans: "Helvetica Neue", Helvetica, Arial, "PingFang SC",
    "Hiragino Sans GB", "Microsoft YaHei", sans-serif;
  --font-mono: "SFMono-Regular", "Cascadia Code", Consolas, monospace;
  --ease-out: cubic-bezier(0.22, 1, 0.36, 1);
}

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

html {
  scroll-behavior: smooth;
  scroll-padding-top: 24px;
}

body {
  margin: 0;
  min-width: 320px;
  background: var(--canvas);
  color: var(--ink);
  font-family: var(--font-sans);
  font-size: 16px;
  line-height: 1.6;
  -webkit-font-smoothing: antialiased;
  text-rendering: optimizeLegibility;
}

body.menu-open {
  overflow: hidden;
}

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

a {
  color: inherit;
  text-decoration-thickness: 1px;
  text-underline-offset: 0.22em;
}

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

button {
  font: inherit;
}

h1,
h2,
h3,
p,
figure {
  margin-top: 0;
}

h1,
h2,
h3 {
  color: var(--ink);
  font-weight: 700;
  letter-spacing: -0.042em;
  text-wrap: balance;
}

h1 {
  max-width: 700px;
  margin-bottom: 28px;
  font-size: clamp(3.5rem, 5.4vw, 5.8rem);
  line-height: 0.98;
}

h2 {
  margin-bottom: 0;
  font-size: clamp(2.55rem, 4.3vw, 4.6rem);
  line-height: 1.02;
}

h3 {
  margin-bottom: 10px;
  font-size: clamp(1.12rem, 1.6vw, 1.42rem);
  line-height: 1.2;
}

p {
  color: var(--muted);
  text-wrap: pretty;
}

code {
  font-family: var(--font-mono);
}

:focus-visible {
  outline: 3px solid var(--blue);
  outline-offset: 4px;
}

.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: 100;
  top: 12px;
  left: 12px;
  padding: 10px 14px;
  background: var(--ink);
  color: var(--white);
  transform: translateY(-160%);
  transition: transform 180ms var(--ease-out);
}

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

.section-inner,
.header-inner,
.hero-inner {
  width: min(var(--container), calc(100% - (var(--gutter) * 2)));
  margin-inline: auto;
}

.section {
  padding-block: var(--section-space);
}

.site-header {
  position: relative;
  z-index: 30;
  height: var(--header-height);
  background: color-mix(in srgb, var(--canvas) 96%, transparent);
  border-bottom: 1px solid var(--hairline);
}

.header-inner {
  display: grid;
  grid-template-columns: auto 1fr auto;
  align-items: center;
  height: 100%;
  gap: clamp(28px, 5vw, 78px);
}

.project-brand {
  display: inline-flex;
  align-items: center;
  gap: 13px;
  color: var(--blue);
  font-size: 1.28rem;
  font-weight: 750;
  letter-spacing: 0.11em;
  text-decoration: none;
  text-transform: uppercase;
}

.project-brand img {
  width: 30px;
  height: 30px;
}

.site-nav {
  display: flex;
  justify-content: center;
  gap: clamp(24px, 3vw, 52px);
}

.site-nav a,
.github-link,
.language-control {
  position: relative;
  padding: 6px 0;
  border: 0;
  background: transparent;
  color: var(--ink);
  font-size: 0.9rem;
  font-weight: 600;
  text-decoration: none;
  cursor: pointer;
}

.site-nav a::after,
.github-link::after,
.language-control::after {
  content: "";
  position: absolute;
  right: 0;
  bottom: 0;
  left: 0;
  height: 1px;
  background: currentColor;
  transform: scaleX(0);
  transform-origin: right;
  transition: transform 180ms var(--ease-out);
}

.site-nav a:hover::after,
.github-link:hover::after,
.language-control:hover::after {
  transform: scaleX(1);
  transform-origin: left;
}

.header-actions {
  display: flex;
  align-items: center;
  gap: 22px;
}

.language-control {
  min-width: 32px;
}

.language-control:disabled {
  cursor: wait;
  opacity: 0.45;
}

.menu-toggle {
  display: none;
}

.hero {
  overflow: clip;
  padding-block: clamp(56px, 7vw, 104px) clamp(72px, 8vw, 118px);
}

.hero-inner {
  display: grid;
  grid-template-columns: minmax(400px, 0.84fr) minmax(520px, 1.16fr);
  align-items: center;
  gap: clamp(42px, 6vw, 102px);
}

.hero-copy {
  position: relative;
  z-index: 2;
}

.hero-lede {
  max-width: 54ch;
  margin-bottom: 34px;
  color: var(--muted);
  font-size: clamp(1.14rem, 1.7vw, 1.42rem);
  line-height: 1.65;
}

.hero-actions {
  display: flex;
  flex-wrap: wrap;
  gap: 14px;
}

.button {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  min-height: 50px;
  padding: 14px 22px;
  border: 1px solid currentColor;
  border-radius: 0;
  font-size: 0.93rem;
  font-weight: 700;
  line-height: 1.2;
  text-decoration: none;
  transition: color 180ms var(--ease-out), background-color 180ms var(--ease-out),
    transform 180ms var(--ease-out);
}

.button:hover {
  transform: translateY(-2px);
}

.button-primary {
  border-color: var(--blue);
  background: var(--blue);
  color: var(--white);
}

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

.button-secondary {
  border-color: var(--blue);
  background: transparent;
  color: var(--blue);
}

.button-secondary:hover {
  background: var(--white);
}

.hero-note {
  margin: 20px 0 0;
  font-size: 0.84rem;
}

.measured-frame {
  position: relative;
  margin: 0;
  border: 1px solid var(--hairline);
  background: var(--white);
}

.measured-frame::before,
.measured-frame::after {
  content: "";
  position: absolute;
  z-index: 2;
  width: 18px;
  height: 18px;
  border-color: var(--muted);
  pointer-events: none;
}

.measured-frame::before {
  top: -9px;
  left: -9px;
  border-top: 1px solid;
  border-left: 1px solid;
}

.measured-frame::after {
  right: -9px;
  bottom: -9px;
  border-right: 1px solid;
  border-bottom: 1px solid;
}

.hero-figure {
  min-width: 0;
  animation: hero-settle 680ms var(--ease-out) both;
}

.hero-figure img {
  position: relative;
  z-index: 1;
  width: 100%;
  height: auto;
  aspect-ratio: 16 / 9;
  object-fit: contain;
}

.hero-plane {
  position: absolute;
  z-index: 0;
  top: 8%;
  right: -18%;
  width: 58%;
  height: 32%;
  background: var(--blue);
  clip-path: polygon(100% 0, 100% 100%, 0 52%);
}

.decision-section {
  background: var(--white);
  border-top: 1px solid var(--hairline);
  border-bottom: 1px solid var(--hairline);
}

.decision-section h2 {
  max-width: 950px;
}

.decision-rail {
  display: grid;
  grid-template-columns: repeat(6, minmax(100px, 1fr));
  align-items: center;
  margin: clamp(58px, 7vw, 96px) 0 0;
  padding: 0;
  list-style: none;
}

.decision-rail li {
  position: relative;
  color: var(--ink);
  font-size: clamp(1rem, 1.6vw, 1.4rem);
  font-weight: 650;
}

.decision-rail li:not(:last-child)::after {
  content: "";
  position: absolute;
  top: 50%;
  right: 13%;
  left: 40%;
  height: 1px;
  background: var(--blue);
}

.decision-rail li:not(:last-child)::before {
  content: "";
  position: absolute;
  z-index: 1;
  top: calc(50% - 3px);
  right: 12%;
  border-width: 3px 0 3px 6px;
  border-style: solid;
  border-color: transparent transparent transparent var(--blue);
}

.decision-rail .is-current {
  color: var(--blue);
}

.capabilities-section {
  padding-bottom: 0;
}

.capabilities-section h2 {
  max-width: 780px;
}

.capability-list {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  margin-top: clamp(58px, 7vw, 94px);
  border-top: 1px solid var(--hairline);
  border-bottom: 1px solid var(--hairline);
}

.capability-list article {
  position: relative;
  min-height: 230px;
  padding: 34px clamp(22px, 2.6vw, 42px) 36px 0;
}

.capability-list article + article {
  padding-left: clamp(22px, 2.6vw, 42px);
  border-left: 1px solid var(--hairline);
}

.capability-list h3 {
  font-size: clamp(1.18rem, 1.8vw, 1.55rem);
}

.capability-list p {
  max-width: 30ch;
  margin-bottom: 0;
  font-size: 1rem;
}

.capability-list .is-emphasized::after {
  content: "";
  position: absolute;
  right: 0;
  bottom: 0;
  left: 0;
  height: 18px;
  background: var(--blue);
  clip-path: polygon(7% 0, 93% 0, 100% 100%, 0 100%);
}

.capability-list .is-emphasized h3 {
  color: var(--blue);
}

.scale-section h2 {
  max-width: 900px;
}

.scale-layout {
  display: grid;
  grid-template-columns: minmax(520px, 1.2fr) minmax(340px, 0.8fr);
  align-items: stretch;
  gap: clamp(58px, 8vw, 128px);
  margin-top: clamp(58px, 7vw, 96px);
}

.scale-figure img {
  width: 100%;
  height: 100%;
  min-height: 410px;
  object-fit: contain;
}

.scale-axis {
  position: relative;
  display: grid;
  align-content: center;
  gap: clamp(68px, 8vw, 112px);
  padding-left: 56px;
}

.scale-axis::before {
  content: "";
  position: absolute;
  top: 8%;
  bottom: 8%;
  left: 0;
  width: 1px;
  background: var(--muted);
}

.scale-axis article {
  position: relative;
}

.scale-axis article::before {
  content: "";
  position: absolute;
  top: 16px;
  left: -63px;
  width: 15px;
  height: 1px;
  background: var(--muted);
}

.scale-axis h3 {
  color: var(--blue);
  font-size: clamp(1.45rem, 2vw, 2rem);
}

.scale-axis p {
  max-width: 44ch;
  margin: 0;
}

.trust-section {
  background: var(--ink);
  color: var(--white);
}

.trust-heading {
  display: grid;
  grid-template-columns: minmax(0, 1.2fr) minmax(320px, 0.65fr);
  align-items: end;
  gap: clamp(52px, 9vw, 140px);
}

.trust-heading h2,
.trust-heading p {
  color: var(--white);
}

.trust-heading h2 {
  max-width: 880px;
}

.trust-heading p {
  max-width: 48ch;
  margin: 0 0 12px;
  color: color-mix(in srgb, var(--white) 76%, transparent);
  font-size: 1.05rem;
}

.trust-rail {
  position: relative;
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  margin-top: clamp(58px, 7vw, 90px);
  padding-top: 28px;
  border-top: 1px solid var(--blue);
}

.trust-rail::before,
.trust-rail::after {
  content: "";
  position: absolute;
  top: -7px;
  width: 13px;
  height: 13px;
}

.trust-rail::before {
  left: 0;
  border-top: 1px solid var(--blue);
  border-left: 1px solid var(--blue);
}

.trust-rail::after {
  right: 0;
  border-top: 1px solid var(--blue);
  border-right: 1px solid var(--blue);
}

.trust-rail span {
  min-height: 42px;
  color: var(--white);
  font-size: clamp(1.05rem, 1.6vw, 1.35rem);
  font-weight: 650;
  text-align: center;
}

.trust-rail span + span {
  border-left: 1px solid var(--blue);
}

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

.skills-layout {
  display: grid;
  grid-template-columns: minmax(300px, 0.72fr) minmax(560px, 1.28fr);
  align-items: center;
  gap: clamp(58px, 9vw, 150px);
}

.skills-layout h2 {
  max-width: 620px;
}

.skills-list {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  margin: 0;
  padding: 0;
  border-top: 1px solid var(--hairline);
  border-bottom: 1px solid var(--hairline);
  list-style: none;
}

.skills-list li {
  display: grid;
  grid-template-columns: 60px 1fr;
  align-items: center;
  min-height: 76px;
  border-bottom: 1px solid var(--hairline);
}

.skills-list li:nth-last-child(-n + 2) {
  border-bottom: 0;
}

.skills-list li:nth-child(even) {
  padding-left: 28px;
  border-left: 1px solid var(--hairline);
}

.skills-list span {
  color: var(--blue);
  font-family: var(--font-mono);
  font-size: 1.05rem;
  font-weight: 700;
}

.skills-list a {
  font-size: 1.05rem;
  font-weight: 650;
  text-decoration: none;
}

.skills-list a:hover {
  color: var(--blue);
}

.start-section {
  background: var(--canvas);
  border-top: 1px solid var(--hairline);
}

.start-layout {
  display: grid;
  grid-template-columns: minmax(500px, 1.2fr) minmax(340px, 0.8fr);
  align-items: end;
  gap: clamp(56px, 8vw, 120px);
}

.start-layout h2 {
  font-size: clamp(2.5rem, 4vw, 4rem);
}

.command-block {
  display: flex;
  align-items: center;
  gap: 22px;
  max-width: 720px;
  margin-top: 28px;
  padding: 17px 18px;
  background: var(--ink);
  color: var(--white);
}

.command-block code {
  flex: 1;
  min-width: 0;
  overflow-wrap: anywhere;
  font-size: 0.9rem;
}

.copy-button {
  flex: none;
  padding: 6px 0;
  border: 0;
  border-bottom: 1px solid currentColor;
  background: transparent;
  color: var(--white);
  font-size: 0.78rem;
  font-weight: 700;
  cursor: pointer;
}

.copy-button.is-copied {
  color: #8bb0ff;
}

.start-actions {
  display: flex;
  justify-content: flex-end;
  gap: 14px;
}

.site-footer {
  padding-block: 42px;
  background: var(--canvas);
  border-top: 1px solid var(--hairline);
}

.footer-inner {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 48px;
}

.footer-identity {
  display: flex;
  align-items: center;
  gap: 24px;
  color: var(--muted);
  font-size: 0.9rem;
}

.footer-identity strong {
  color: var(--ink);
}

.footer-identity img {
  width: 66px;
  height: auto;
  padding-left: 22px;
  border-left: 1px solid var(--hairline);
}

.footer-links {
  display: flex;
  flex-wrap: wrap;
  gap: 18px 34px;
}

.footer-links a {
  color: var(--muted);
  font-size: 0.85rem;
  text-decoration: none;
}

.footer-links a:hover {
  color: var(--blue);
}

.copy-status {
  position: fixed;
  z-index: 60;
  right: 22px;
  bottom: 22px;
  max-width: min(340px, calc(100vw - 44px));
  padding: 12px 16px;
  background: var(--ink);
  color: var(--white);
  font-size: 0.86rem;
  opacity: 0;
  pointer-events: none;
  transform: translateY(12px);
  transition: opacity 180ms var(--ease-out), transform 180ms var(--ease-out);
}

.copy-status.is-visible {
  opacity: 1;
  transform: translateY(0);
}

html[data-lang="zh-CN"] h1 {
  max-width: 8.5em;
  font-size: clamp(3.5rem, 5.1vw, 5.45rem);
  line-height: 1.08;
}

html[data-lang="zh-CN"] .hero-lede {
  max-width: 29em;
}

html[data-lang="zh-CN"] .decision-section h2,
html[data-lang="zh-CN"] .scale-section h2 {
  max-width: 12em;
}

@keyframes hero-settle {
  from {
    opacity: 0;
    transform: translateY(18px);
  }
  to {
    opacity: 1;
    transform: translateY(0);
  }
}

@media (max-width: 1120px) {
  .hero-inner {
    grid-template-columns: 1fr;
  }

  .hero-copy {
    max-width: 840px;
  }

  .hero-figure {
    max-width: 880px;
  }

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

  .capability-list article:nth-child(3) {
    border-left: 0;
    border-top: 1px solid var(--hairline);
  }

  .capability-list article:nth-child(4) {
    border-top: 1px solid var(--hairline);
  }

  .scale-layout,
  .skills-layout,
  .start-layout {
    grid-template-columns: 1fr;
  }

  .scale-figure {
    max-width: 880px;
  }

  .start-actions {
    justify-content: flex-start;
  }
}

@media (max-width: 820px) {
  :root {
    --header-height: 68px;
  }

  .header-inner {
    grid-template-columns: auto 1fr auto;
  }

  .project-brand {
    font-size: 1.06rem;
  }

  .site-nav {
    position: fixed;
    z-index: 25;
    inset: var(--header-height) 0 auto;
    display: grid;
    gap: 0;
    padding: 18px var(--gutter) 26px;
    background: var(--canvas);
    border-bottom: 1px solid var(--hairline);
    opacity: 0;
    pointer-events: none;
    transform: translateY(-12px);
    transition: opacity 180ms var(--ease-out), transform 180ms var(--ease-out);
  }

  .site-nav.is-open {
    opacity: 1;
    pointer-events: auto;
    transform: translateY(0);
  }

  .site-nav a {
    padding: 14px 0;
    border-bottom: 1px solid var(--hairline);
  }

  .menu-toggle {
    display: grid;
    justify-self: end;
    width: 38px;
    height: 38px;
    padding: 10px 7px;
    border: 0;
    background: transparent;
    cursor: pointer;
  }

  .menu-toggle span:not(.sr-only) {
    display: block;
    width: 24px;
    height: 1px;
    background: var(--ink);
    transition: transform 180ms var(--ease-out);
  }

  .menu-toggle[aria-expanded="true"] span:first-child {
    transform: translateY(5px) rotate(45deg);
  }

  .menu-toggle[aria-expanded="true"] span:nth-child(2) {
    transform: translateY(-5px) rotate(-45deg);
  }

  .header-actions {
    gap: 16px;
  }

  .github-link {
    display: none;
  }

  .decision-rail {
    grid-template-columns: repeat(3, 1fr);
    gap: 34px 0;
  }

  .decision-rail li:nth-child(3)::after,
  .decision-rail li:nth-child(3)::before {
    display: none;
  }

  .trust-heading {
    grid-template-columns: 1fr;
  }

  .trust-heading p {
    margin: 0;
  }

  .trust-rail {
    grid-template-columns: repeat(2, 1fr);
    gap: 24px 0;
  }

  .trust-rail span:nth-child(3) {
    border-left: 0;
  }

  .skills-list {
    grid-template-columns: 1fr;
  }

  .skills-list li:nth-last-child(-n + 2) {
    border-bottom: 1px solid var(--hairline);
  }

  .skills-list li:last-child {
    border-bottom: 0;
  }

  .skills-list li:nth-child(even) {
    padding-left: 0;
    border-left: 0;
  }

  .footer-inner {
    align-items: flex-start;
    flex-direction: column;
  }
}

@media (max-width: 600px) {
  :root {
    --gutter: 20px;
    --section-space: 70px;
  }

  h1 {
    font-size: clamp(3rem, 15vw, 4.2rem);
  }

  h2 {
    font-size: clamp(2.25rem, 11vw, 3.25rem);
  }

  .hero {
    padding-top: 42px;
  }

  .hero-actions,
  .start-actions {
    display: grid;
    grid-template-columns: 1fr;
  }

  .button {
    width: 100%;
  }

  .capability-list {
    grid-template-columns: 1fr;
  }

  .capability-list article,
  .capability-list article + article {
    min-height: 0;
    padding: 28px 0 34px;
    border-top: 1px solid var(--hairline);
    border-left: 0;
  }

  .capability-list article:first-child {
    border-top: 0;
  }

  .scale-layout {
    gap: 52px;
  }

  .scale-figure img {
    min-height: 0;
  }

  .scale-axis {
    gap: 52px;
    padding-left: 38px;
  }

  .scale-axis article::before {
    left: -45px;
  }

  .trust-rail {
    grid-template-columns: 1fr;
  }

  .trust-rail span {
    padding: 14px 0;
    border-left: 0 !important;
    border-bottom: 1px solid color-mix(in srgb, var(--white) 20%, transparent);
    text-align: left;
  }

  .command-block {
    align-items: stretch;
    flex-direction: column;
  }

  .copy-button {
    align-self: flex-start;
  }

  .footer-identity {
    align-items: flex-start;
    flex-direction: column;
  }

  .footer-identity img {
    padding: 0;
    border-left: 0;
  }
}

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

  *,
  *::before,
  *::after {
    animation-duration: 0.01ms !important;
    animation-iteration-count: 1 !important;
    transition-duration: 0.01ms !important;
  }
}