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

html {
  scroll-behavior: smooth;
}

body {
  min-width: 20rem;
  margin: 0;
  color: var(--ink);
  background: var(--white);
  font-family: "Zhigou Sans", "PingFang SC", "Microsoft YaHei", sans-serif;
  font-size: 1rem;
  line-height: 1.7;
  text-rendering: optimizelegibility;
}

body.is-menu-open {
  overflow: hidden;
}

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

a {
  color: inherit;
  text-decoration-thickness: 0.08em;
  text-underline-offset: 0.22em;
}

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

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

:focus-visible {
  outline: 0.2rem solid var(--academic-purple);
  outline-offset: 0.24rem;
}

::selection {
  color: var(--white);
  background: var(--academic-purple);
}

.shell {
  width: min(var(--shell), calc(100% - 4rem));
  margin-inline: auto;
}

.skip-link {
  position: fixed;
  z-index: 1000;
  top: 0.75rem;
  left: 0.75rem;
  padding: 0.7rem 1rem;
  color: var(--white);
  background: var(--ink);
  transform: translateY(-200%);
}

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

.section-anchor {
  scroll-margin-top: calc(var(--header-height) + 1.5rem);
}

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

.section-kicker {
  display: flex;
  align-items: center;
  gap: 0.7rem;
  margin: 0 0 1rem;
  color: var(--engineering-blue);
  font-family: "Zhigou Mono", monospace;
  font-size: 0.95rem;
  font-weight: 400;
  letter-spacing: 0.13em;
  text-transform: uppercase;
}

.section-kicker::before {
  width: 1.5rem;
  height: 1px;
  background: currentcolor;
  content: "";
}

.section-kicker span {
  color: var(--academic-purple);
}

.section-kicker--light {
  color: var(--structure-blue);
}

.section-kicker--light span {
  color: var(--white);
}

.section-heading {
  display: grid;
  grid-template-columns: minmax(0, 1.35fr) minmax(18rem, 0.65fr);
  gap: clamp(2rem, 7vw, 7rem);
  align-items: end;
  margin-bottom: clamp(2.25rem, 5vw, 4.5rem);
}

.section-heading h2,
.advantages h2,
.about h2,
.contact h2,
.legal-page h1,
.error-page h1 {
  margin: 0;
  font-family: "Zhigou Serif", "Songti SC", serif;
  font-size: clamp(2.35rem, 5.2vw, 4.6rem);
  font-weight: 600;
  line-height: 1.2;
  letter-spacing: -0.035em;
}

.section-heading > p {
  margin: 0 0 0.4rem;
  color: var(--ink-72);
  font-size: 1.05rem;
}

.button {
  display: inline-flex;
  min-height: 3.2rem;
  align-items: center;
  justify-content: center;
  gap: 0.6rem;
  padding: 0.75rem 1.45rem;
  border: 1px solid transparent;
  font-weight: 600;
  text-decoration: none;
  transition: transform 180ms var(--ease-out), background-color 180ms ease, color 180ms ease;
}

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

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

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

.button--quiet {
  border-color: var(--ink-12);
  color: var(--ink);
  background: var(--white);
}

.button--quiet:hover {
  border-color: var(--ink);
}

/* Header */
.site-header {
  position: sticky;
  z-index: 100;
  top: 0;
  height: var(--header-height);
  border-bottom: 1px solid var(--ink-12);
  background: rgb(255 255 255 / 94%);
  backdrop-filter: blur(1rem);
}

.site-header__inner {
  display: flex;
  height: 100%;
  align-items: center;
  justify-content: space-between;
  gap: 2rem;
}

.brand {
  display: inline-flex;
  flex: 0 0 auto;
  align-items: center;
  gap: 0.85rem;
  text-decoration: none;
}

.brand__seal {
  width: 2.7rem;
  height: 2.7rem;
}

.brand__name {
  font-family: "Zhigou Serif", "Songti SC", serif;
  font-size: 1.25rem;
  font-weight: 600;
  letter-spacing: 0.16em;
}

.site-nav__list {
  display: flex;
  align-items: center;
  gap: clamp(1rem, 2.2vw, 2rem);
  margin: 0;
  padding: 0;
  list-style: none;
}

.site-nav a {
  position: relative;
  display: inline-flex;
  min-height: 2.75rem;
  align-items: center;
  color: var(--ink-72);
  font-size: 0.9rem;
  font-weight: 600;
  text-decoration: none;
}

.site-nav a::after {
  position: absolute;
  right: 0;
  bottom: 0.1rem;
  left: 0;
  height: 2px;
  background: var(--seal-red);
  content: "";
  transform: scaleX(0);
  transform-origin: right;
  transition: transform 180ms var(--ease-out);
}

.site-nav a:hover,
.site-nav a[aria-current="location"] {
  color: var(--ink);
}

.site-nav a:hover::after,
.site-nav a[aria-current="location"]::after {
  transform: scaleX(1);
  transform-origin: left;
}

.menu-toggle {
  display: none;
  min-width: 3.4rem;
  min-height: 2.9rem;
  align-items: center;
  justify-content: center;
  gap: 0.6rem;
  border: 1px solid var(--ink-12);
  color: var(--ink);
  background: transparent;
  cursor: pointer;
}

.menu-toggle__label {
  font-size: 0.82rem;
  font-weight: 600;
}

.menu-toggle__icon {
  display: grid;
  width: 1rem;
  gap: 0.25rem;
}

.menu-toggle__icon i {
  display: block;
  height: 1px;
  background: currentcolor;
  transition: transform 180ms ease;
}

.menu-toggle[aria-expanded="true"] .menu-toggle__icon i:first-child {
  transform: translateY(0.15rem) rotate(45deg);
}

.menu-toggle[aria-expanded="true"] .menu-toggle__icon i:last-child {
  transform: translateY(-0.15rem) rotate(-45deg);
}

/* Hero */
.hero {
  position: relative;
  overflow: hidden;
  border-bottom: 1px solid var(--structure-blue);
  background:
    linear-gradient(90deg, rgb(217 230 248 / 42%) 1px, transparent 1px) 0 0 / 5rem 5rem,
    linear-gradient(rgb(217 230 248 / 42%) 1px, transparent 1px) 0 0 / 5rem 5rem,
    var(--mist);
}

.hero::before {
  position: absolute;
  top: 0;
  bottom: 0;
  left: calc(50% - 1px);
  width: 1px;
  background: var(--structure-blue);
  content: "";
}

.hero__grid {
  display: grid;
  min-height: calc(100svh - var(--header-height));
  grid-template-columns: minmax(0, 5fr) minmax(0, 7fr);
  align-items: center;
}

.hero__content {
  position: relative;
  z-index: 2;
  padding: clamp(3.5rem, 7vw, 6.5rem) clamp(2rem, 6vw, 5.5rem) clamp(3.25rem, 6.5vw, 5.5rem) 0;
}

.hero h1 {
  margin: 0;
  font-family: "Zhigou Serif", "Songti SC", serif;
  font-size: clamp(3.1rem, 4.8vw, 4.8rem);
  font-weight: 600;
  line-height: 1.13;
  letter-spacing: -0.055em;
}

.hero h1 em {
  position: relative;
  color: var(--ink);
  font-style: normal;
}

.hero h1 em::after {
  position: absolute;
  right: 0.05em;
  bottom: -0.09em;
  width: 0.62em;
  height: 0.11em;
  background: var(--seal-red);
  content: "";
}

.hero__lead {
  max-width: 37rem;
  margin: 2rem 0 0;
  color: var(--ink-72);
  font-size: clamp(1rem, 1.4vw, 1.15rem);
  line-height: 1.9;
}

.hero__actions {
  display: flex;
  flex-wrap: wrap;
  gap: 0.9rem;
  margin-top: 2.35rem;
}

.hero__principles {
  display: grid;
  grid-template-columns: repeat(3, minmax(0, 1fr));
  gap: 1rem;
  margin: clamp(3rem, 6vw, 5rem) 0 0;
}

.hero__principles div {
  border-top: 1px solid var(--ink-12);
  padding-top: 0.85rem;
}

.hero__principles dt {
  color: var(--academic-purple);
  font-family: "Zhigou Mono", monospace;
  font-size: 0.75rem;
}

.hero__principles dd {
  margin: 0.2rem 0 0;
  color: var(--ink-72);
  font-size: 0.84rem;
}

.hero__visual {
  padding: clamp(1.5rem, 3.5vw, 3.5rem) 0 clamp(1.5rem, 3.5vw, 3.5rem) clamp(1.5rem, 3.5vw, 3.5rem);
}

.system-map {
  position: relative;
  padding: clamp(1rem, 3vw, 2rem);
  border: 1px solid var(--structure-blue);
  background: rgb(255 255 255 / 68%);
  box-shadow: var(--shadow-soft);
}

.system-map::before,
.system-map::after {
  position: absolute;
  width: 0.75rem;
  height: 0.75rem;
  border-color: var(--academic-purple);
  content: "";
}

.system-map::before {
  top: -1px;
  left: -1px;
  border-top: 2px solid;
  border-left: 2px solid;
}

.system-map::after {
  right: -1px;
  bottom: -1px;
  border-right: 2px solid;
  border-bottom: 2px solid;
}

.system-map svg {
  width: 100%;
  height: auto;
}

.system-map__grid path {
  fill: none;
  stroke: var(--structure-blue);
  stroke-width: 1;
}

.system-map__paths path {
  fill: none;
  stroke: var(--engineering-blue);
  stroke-dasharray: 620;
  stroke-dashoffset: 0;
  stroke-width: 2;
}

.system-map__nodes circle {
  fill: var(--engineering-blue);
}

.system-map__nodes .system-map__node--purple {
  fill: var(--academic-purple);
}

.system-map__modules rect {
  fill: var(--white);
  stroke: var(--ink);
  stroke-width: 1.5;
}

.system-map__modules path {
  fill: none;
  stroke: var(--structure-blue);
  stroke-width: 5;
}

.system-map__labels {
  fill: var(--ink-58);
  font-family: "Zhigou Mono", monospace;
  font-size: 12px;
  letter-spacing: 0.08em;
}

.system-map__seal rect {
  fill: var(--seal-red);
}

.system-map__caption {
  display: flex;
  justify-content: space-between;
  gap: 1rem;
  margin: 1rem 0 0;
  color: var(--ink-58);
  font-family: "Zhigou Mono", monospace;
  font-size: 0.75rem;
  letter-spacing: 0.08em;
}

.system-map__caption strong {
  color: var(--academic-purple);
  font-weight: 400;
}

.js-enabled .system-map__paths path {
  stroke-dashoffset: 620;
}

.js-enabled .system-map__nodes,
.js-enabled .system-map__modules,
.js-enabled .system-map__seal {
  opacity: 0;
}

.js-enabled .system-map.is-ready .system-map__paths path {
  stroke-dashoffset: 0;
  transition: stroke-dashoffset 550ms var(--ease-out) 100ms;
}

.js-enabled .system-map.is-ready .system-map__nodes {
  opacity: 1;
  transition: opacity 180ms ease;
}

.js-enabled .system-map.is-ready .system-map__modules {
  opacity: 1;
  transition: opacity 260ms ease 480ms;
}

.js-enabled .system-map.is-ready .system-map__seal {
  opacity: 1;
  transition: opacity 220ms ease 780ms;
}

/* Services */
.services {
  background: var(--white);
}

.service-list {
  border-top: 1px solid var(--ink);
}

.service-item {
  display: grid;
  grid-template-columns: 4rem minmax(15rem, 1fr) minmax(16rem, 0.7fr);
  gap: clamp(1.25rem, 4vw, 4rem);
  align-items: start;
  padding-block: clamp(2rem, 4vw, 3.25rem);
  border-bottom: 1px solid var(--ink-12);
}

.service-item__index {
  color: var(--seal-red);
  font-family: "Zhigou Mono", monospace;
  font-size: 0.88rem;
}

.service-item h3 {
  margin: 0 0 0.65rem;
  font-family: "Zhigou Serif", "Songti SC", serif;
  font-size: clamp(1.55rem, 2.6vw, 2.35rem);
  font-weight: 600;
}

.service-item p {
  max-width: 37rem;
  margin: 0;
  color: var(--ink-72);
}

.service-item ul {
  display: grid;
  gap: 0.6rem;
  margin: 0;
  padding: 0;
  color: var(--ink-72);
  list-style: none;
}

.service-item li::before {
  margin-right: 0.7rem;
  color: var(--engineering-blue);
  content: "+";
}

/* Advantages */
.advantages {
  position: relative;
  overflow: hidden;
  color: var(--white);
  background: var(--ink);
}

.advantages::after {
  position: absolute;
  top: -10rem;
  right: -8rem;
  width: 30rem;
  height: 30rem;
  border: 1px solid var(--academic-purple);
  content: "";
  opacity: 0.4;
  transform: rotate(18deg);
}

.advantages__grid {
  position: relative;
  z-index: 1;
  display: grid;
  grid-template-columns: minmax(16rem, 0.72fr) minmax(0, 1.28fr);
  gap: clamp(3rem, 8vw, 8rem);
}

.advantages__intro > p:last-child {
  max-width: 24rem;
  margin: 1.5rem 0 0;
  color: rgb(255 255 255 / 68%);
}

.advantage-map {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  border-top: 1px solid rgb(255 255 255 / 22%);
  border-left: 1px solid rgb(255 255 255 / 22%);
}

.advantage-map article {
  min-height: 15rem;
  padding: clamp(1.5rem, 4vw, 2.5rem);
  border-right: 1px solid rgb(255 255 255 / 22%);
  border-bottom: 1px solid rgb(255 255 255 / 22%);
}

.advantage-map span {
  color: var(--academic-purple);
  font-family: "Zhigou Serif", "Songti SC", serif;
  font-size: 2.2rem;
}

.advantage-map h3 {
  margin: 2rem 0 0.6rem;
  font-size: 1.2rem;
}

.advantage-map p {
  margin: 0;
  color: rgb(255 255 255 / 66%);
  font-size: 0.92rem;
}

/* Delivery */
.delivery {
  background: var(--mist);
}

.delivery-steps {
  display: grid;
  grid-template-columns: repeat(4, minmax(0, 1fr));
  margin: 0;
  padding: 0;
  list-style: none;
}

.delivery-steps > li {
  position: relative;
  min-height: 23rem;
  padding: 1.5rem clamp(1.25rem, 2.5vw, 2rem);
  border-top: 2px solid var(--engineering-blue);
  border-right: 1px solid var(--structure-blue);
  background: rgb(255 255 255 / 58%);
}

.delivery-steps > li:first-child {
  border-left: 1px solid var(--structure-blue);
}

.delivery-steps > li::before {
  position: absolute;
  top: -0.42rem;
  left: 1.6rem;
  width: 0.7rem;
  height: 0.7rem;
  border: 2px solid var(--engineering-blue);
  border-radius: 50%;
  background: var(--mist);
  content: "";
}

.delivery-steps > li > span {
  color: var(--academic-purple);
  font-family: "Zhigou Mono", monospace;
  font-size: 0.78rem;
}

.delivery-steps h3 {
  margin: 4rem 0 1rem;
  font-family: "Zhigou Serif", "Songti SC", serif;
  font-size: 1.65rem;
  font-weight: 600;
}

.delivery-steps p {
  margin: 0;
  color: var(--ink-72);
}

.delivery-steps small {
  display: block;
  margin-top: 2rem;
  padding-top: 1rem;
  border-top: 1px solid var(--structure-blue);
  color: var(--ink-58);
  font-size: 0.78rem;
}

/* Experience */
.experience-list {
  display: grid;
  gap: 1.5rem;
}

.experience-list article {
  display: grid;
  grid-template-columns: minmax(16rem, 0.7fr) minmax(0, 1.3fr);
  gap: clamp(2rem, 6vw, 6rem);
  padding: clamp(2rem, 4vw, 3.5rem);
  border: 1px solid var(--structure-blue);
  background:
    linear-gradient(90deg, rgb(217 230 248 / 45%) 1px, transparent 1px) 0 0 / 3rem 3rem,
    var(--white);
}

.experience-list header span {
  color: var(--academic-purple);
  font-family: "Zhigou Mono", monospace;
  font-size: 0.75rem;
  letter-spacing: 0.1em;
}

.experience-list h3 {
  max-width: 20rem;
  margin: 1rem 0 0;
  font-family: "Zhigou Serif", "Songti SC", serif;
  font-size: clamp(1.55rem, 2.6vw, 2.25rem);
  font-weight: 600;
  line-height: 1.35;
}

.experience-list dl {
  display: grid;
  gap: 1.25rem;
  margin: 0;
}

.experience-list dl div {
  display: grid;
  grid-template-columns: 3.5rem 1fr;
  gap: 1rem;
  padding-bottom: 1.25rem;
  border-bottom: 1px solid var(--ink-12);
}

.experience-list dl div:last-child {
  padding-bottom: 0;
  border-bottom: 0;
}

.experience-list dt {
  color: var(--engineering-blue);
  font-size: 0.78rem;
  font-weight: 600;
}

.experience-list dd {
  margin: 0;
  color: var(--ink-72);
}

/* About */
.about {
  background: var(--mist);
}

.about__grid {
  display: grid;
  grid-template-columns: minmax(18rem, 0.8fr) minmax(0, 1.2fr);
  gap: clamp(3rem, 9vw, 9rem);
  align-items: center;
}

.about__mark {
  position: relative;
  display: grid;
  aspect-ratio: 1;
  grid-template-columns: repeat(2, 1fr);
  border: 1px solid var(--structure-blue);
  background: var(--white);
}

.about__mark::before,
.about__mark::after {
  position: absolute;
  background: var(--structure-blue);
  content: "";
}

.about__mark::before {
  top: 50%;
  right: 0;
  left: 0;
  height: 1px;
}

.about__mark::after {
  top: 0;
  bottom: 0;
  left: 50%;
  width: 1px;
}

.about__mark > span {
  display: grid;
  place-items: center;
  color: var(--ink-12);
  font-family: "Zhigou Serif", "Songti SC", serif;
  font-size: clamp(3rem, 8vw, 7rem);
}

.about__mark img {
  position: absolute;
  right: -2rem;
  bottom: -2rem;
  width: clamp(5rem, 10vw, 8rem);
  background: var(--white);
}

.about__lead {
  max-width: 42rem;
  margin: 2rem 0 0;
  color: var(--ink-72);
  font-size: clamp(1.05rem, 1.7vw, 1.25rem);
  line-height: 2;
}

.about__values {
  display: flex;
  flex-wrap: wrap;
  gap: 0.75rem;
  margin-top: 2.25rem;
}

.about__values span {
  padding: 0.55rem 0.9rem;
  border: 1px solid var(--structure-blue);
  color: var(--ink-72);
  background: var(--white);
  font-size: 0.82rem;
}

/* Contact */
.contact {
  background: var(--white);
}

.contact__grid {
  display: grid;
  grid-template-columns: minmax(18rem, 0.78fr) minmax(30rem, 1.22fr);
  gap: clamp(3rem, 6vw, 6rem);
  align-items: start;
}

.contact h2 {
  font-size: clamp(2.55rem, 4.2vw, 4rem);
  line-height: 1.16;
  letter-spacing: -0.04em;
}

.contact__intro > p:not(.section-kicker) {
  max-width: 40rem;
  margin: 2rem 0 0;
  color: var(--ink-72);
  font-size: 1.05rem;
}

.contact__intro ul {
  display: grid;
  gap: 0.65rem;
  margin: 2rem 0 0;
  padding: 0;
  color: var(--ink-72);
  list-style: none;
}

.contact__intro li::before {
  display: inline-block;
  width: 0.45rem;
  height: 0.45rem;
  margin-right: 0.8rem;
  background: var(--academic-purple);
  content: "";
  transform: rotate(45deg);
}

.contact-card {
  position: relative;
  overflow: hidden;
  padding: clamp(2rem, 5vw, 3.5rem);
  color: var(--white);
  background: var(--ink);
  box-shadow: var(--shadow-soft);
}

.contact-card::before {
  position: absolute;
  top: 0;
  right: 0;
  width: 35%;
  height: 0.3rem;
  background: var(--academic-purple);
  content: "";
}

.contact-card__label {
  color: var(--structure-blue);
  font-family: "Zhigou Mono", monospace;
  font-size: 0.8rem;
  letter-spacing: 0.1em;
}

.contact-card > p {
  margin: 2.5rem 0 1rem;
  color: rgb(255 255 255 / 72%);
}

.contact-card__email {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 1rem;
  padding-block: 1rem;
  border-bottom: 1px solid rgb(255 255 255 / 25%);
  color: var(--white);
  font-size: clamp(1rem, 2.3vw, 1.45rem);
  font-weight: 600;
  text-decoration: none;
}

.contact-card__email span {
  color: var(--seal-red);
  font-size: 1.8rem;
}

.contact-card__notice {
  display: flex;
  gap: 0.8rem;
  margin-top: 2rem;
  color: rgb(255 255 255 / 60%);
  font-size: 0.78rem;
}

.contact-card__notice > span {
  width: 0.5rem;
  height: 0.5rem;
  flex: 0 0 auto;
  margin-top: 0.45rem;
  border-radius: 50%;
  background: var(--academic-purple);
}

.contact-card__notice p {
  margin: 0;
}

.contact-card__notice strong {
  display: block;
  color: var(--white);
  font-weight: 600;
}

.contact-card > img {
  width: 4.25rem;
  margin: 3rem 0 0 auto;
}

.contact__direct {
  display: grid;
  gap: 0.45rem;
  margin-top: 2.25rem;
  padding-top: 1.5rem;
  border-top: 1px solid var(--structure-blue);
}

.contact__direct > span {
  color: var(--ink-58);
  font-family: "Zhigou Mono", monospace;
  font-size: 0.78rem;
  letter-spacing: 0.08em;
}

.contact__direct a {
  color: var(--ink);
  font-size: clamp(1rem, 2vw, 1.25rem);
  font-weight: 600;
  text-decoration-color: var(--structure-blue);
  text-underline-offset: 0.3em;
}

.contact-form-card {
  overflow: visible;
  padding: clamp(1.4rem, 2.8vw, 2.15rem);
  scroll-margin-top: calc(var(--header-height) + 1.5rem);
}

.contact-form-card h3 {
  max-width: none;
  margin: 0.65rem 0 0;
  color: var(--white);
  font-size: clamp(1.15rem, 1.8vw, 1.5rem);
  line-height: 1.4;
  text-wrap: pretty;
}

.contact-form {
  display: grid;
  gap: 0.8rem;
  margin-top: 1.25rem;
}

.contact-form__row {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 0.8rem;
}

.form-field {
  display: grid;
  gap: 0.3rem;
  align-content: start;
}

.form-field label,
.form-consent label {
  color: var(--white);
  font-size: 0.9rem;
  font-weight: 600;
}

.form-field label > span[aria-hidden="true"] {
  color: #ff9f90;
}

.form-field__optional {
  margin-left: 0.35rem;
  color: rgb(255 255 255 / 48%);
  font-size: 0.75rem;
  font-weight: 400;
}

.form-field input,
.form-field select,
.form-field textarea {
  width: 100%;
  min-height: 2.7rem;
  padding: 0.6rem 0.75rem;
  border: 1px solid rgb(255 255 255 / 24%);
  border-radius: 0.35rem;
  color: var(--ink);
  background: var(--white);
  font: inherit;
}

.form-field textarea {
  min-height: 6rem;
  resize: vertical;
  line-height: 1.55;
}

.form-field input:focus-visible,
.form-field select:focus-visible,
.form-field textarea:focus-visible {
  border-color: var(--structure-blue);
  outline: 3px solid rgb(47 111 235 / 32%);
  outline-offset: 2px;
}

.form-field--error input,
.form-field--error select,
.form-field--error textarea {
  border-color: #d96354;
}

.form-field__help,
.form-field__error {
  margin: 0;
  font-size: 0.74rem;
  line-height: 1.4;
}

.form-field__help {
  color: rgb(255 255 255 / 55%);
}

.form-field__error {
  color: #ffb2a7;
}

.form-consent {
  display: grid;
  grid-template-columns: auto 1fr;
  gap: 0.55rem;
  align-items: start;
}

.form-consent input {
  width: 1.15rem;
  height: 1.15rem;
  margin-top: 0.18rem;
  accent-color: var(--engineering-blue);
}

.form-consent label {
  color: rgb(255 255 255 / 76%);
  font-weight: 400;
  line-height: 1.45;
}

.form-consent a,
.contact-form__status a {
  color: var(--white);
  text-underline-offset: 0.25em;
}

.form-consent .form-field__error {
  grid-column: 2;
}

.contact-form__submit {
  width: 100%;
  min-height: 2.85rem;
  margin-top: 0.1rem;
  border: 0;
}

.contact-form__submit:disabled {
  cursor: wait;
  opacity: 0.7;
}

.contact-form__status,
.contact-form__errors {
  margin-top: 1.5rem;
  padding: 1rem 1.1rem;
  border-left: 3px solid var(--engineering-blue);
  color: var(--white);
  background: rgb(255 255 255 / 8%);
}

.contact-form__status--error,
.contact-form__errors {
  border-left-color: #d96354;
}

.contact-form__status strong,
.contact-form__errors strong {
  display: block;
}

.contact-form__status p,
.contact-form__errors ul {
  margin: 0.4rem 0 0;
  color: rgb(255 255 255 / 68%);
  font-size: 0.84rem;
  line-height: 1.65;
}

.contact-form__errors ul {
  padding-left: 1.15rem;
}

.contact-form__errors a {
  color: var(--white);
}

.contact-form__trap {
  position: absolute;
  left: -10000px;
  width: 1px;
  height: 1px;
  overflow: hidden;
}

/* Footer */
.site-footer {
  padding-block: 2.5rem 1.5rem;
  color: var(--white);
  background: var(--ink);
}

.site-footer__inner {
  display: grid;
  grid-template-columns: 1fr auto;
  gap: 1.5rem 4rem;
  align-items: start;
}

.site-footer__brand {
  display: flex;
  align-items: center;
  gap: 1rem;
}

.site-footer__brand img {
  width: 3.5rem;
}

.site-footer__brand div {
  display: grid;
}

.site-footer__brand strong {
  font-family: "Zhigou Serif", "Songti SC", serif;
  font-size: 1.25rem;
  letter-spacing: 0.12em;
}

.site-footer__brand span {
  color: rgb(255 255 255 / 55%);
  font-size: 0.76rem;
}

.site-footer__links {
  display: flex;
  flex-wrap: wrap;
  justify-content: end;
  gap: 0.75rem 1.5rem;
}

.site-footer__links a {
  color: rgb(255 255 255 / 72%);
  font-size: 0.82rem;
}

.site-footer__links a:hover {
  color: var(--white);
}

.site-footer__filing-link {
  align-items: center;
  display: inline-flex;
  gap: 0.35rem;
}

.site-footer__filing-icon {
  flex: 0 0 auto;
  width: 1rem;
  height: auto;
}

.site-footer__copyright {
  margin: 0;
  align-self: center;
  color: rgb(255 255 255 / 45%);
  font-size: 0.72rem;
}

/* Legal and errors */
.legal-page {
  padding-block: clamp(4rem, 9vw, 8rem);
}

.legal-page__header {
  max-width: 54rem;
  padding-bottom: 3rem;
  border-bottom: 1px solid var(--ink);
}

.legal-page__header > p:last-child {
  margin: 1.5rem 0 0;
  color: var(--ink-58);
  font-family: "Zhigou Mono", monospace;
  font-size: 0.75rem;
}

.legal-page__body {
  display: grid;
  max-width: 54rem;
  gap: 0;
}

.legal-page__body section {
  display: grid;
  grid-template-columns: minmax(10rem, 0.36fr) minmax(0, 0.64fr);
  gap: 2rem;
  padding-block: 2rem;
  border-bottom: 1px solid var(--ink-12);
}

.legal-page__body h2 {
  margin: 0;
  font-size: 1rem;
}

.legal-page__body p {
  margin: 0;
  color: var(--ink-72);
}

.back-link {
  display: inline-block;
  margin-top: 3rem;
  color: var(--engineering-blue);
  font-weight: 600;
}

.error-page {
  display: grid;
  min-height: 65vh;
  grid-template-columns: minmax(14rem, 0.65fr) minmax(0, 1.35fr);
  gap: clamp(2rem, 8vw, 8rem);
  align-items: center;
  padding-block: clamp(4rem, 10vw, 8rem);
}

.error-page__code {
  color: var(--structure-blue);
  font-family: "Zhigou Mono", monospace;
  font-size: clamp(6rem, 18vw, 14rem);
  font-weight: 600;
  line-height: 0.8;
}

.error-page__content > p:not(.section-kicker, .error-page__request) {
  max-width: 37rem;
  margin: 1.5rem 0 2rem;
  color: var(--ink-72);
}

.error-page__request {
  margin: -1rem 0 2rem;
  color: var(--ink-58);
  font-size: 0.78rem;
}

.error-page__request code {
  font-family: "Zhigou Mono", monospace;
}

@media (height <= 45rem) and (width >= 64rem) {
  :root {
    --header-height: 4rem;
    --space-section: clamp(3.25rem, 6vw, 4.75rem);
  }

  .hero__content {
    padding-top: 1.5rem;
    padding-bottom: 1.25rem;
  }

  .hero__content .section-kicker {
    margin-bottom: 0.65rem;
  }

  .hero__lead {
    margin-top: 0.9rem;
    line-height: 1.65;
  }

  .hero__actions {
    margin-top: 1.05rem;
  }

  .hero__actions .button {
    min-height: 2.8rem;
    padding-block: 0.55rem;
  }

  .hero__principles {
    margin-top: 1.25rem;
  }

  .hero__visual {
    display: flex;
    justify-content: flex-end;
    padding-top: 0.75rem;
    padding-bottom: 0.75rem;
    padding-left: 1.5rem;
  }

  .system-map {
    width: min(100%, 29rem);
    padding: 1rem;
  }

  .system-map__caption {
    margin-top: 0.6rem;
  }
}

@media (width < 64rem) {
  .shell {
    width: min(var(--shell), calc(100% - 3rem));
  }

  .hero::before {
    display: none;
  }

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

  .hero__content {
    padding-right: 0;
  }

  .hero__visual {
    padding: 0 0 4rem;
  }

  .advantages__grid,
  .about__grid,
  .contact__grid {
    grid-template-columns: 1fr;
  }

  .about__mark {
    width: min(32rem, 82vw);
  }

  .delivery-steps {
    grid-template-columns: repeat(2, minmax(0, 1fr));
  }

  .delivery-steps > li:nth-child(3) {
    border-left: 1px solid var(--structure-blue);
  }
}

@media (width < 48rem) {
  :root {
    --header-height: 4.4rem;
  }

  .shell {
    width: calc(100% - 2.5rem);
  }

  body:not(.js-enabled) .site-header {
    position: relative;
    height: auto;
  }

  body:not(.js-enabled) .site-header__inner {
    min-height: var(--header-height);
    flex-wrap: wrap;
    padding-block: 0.5rem;
  }

  body:not(.js-enabled) .site-nav {
    width: 100%;
  }

  body:not(.js-enabled) .site-nav__list {
    padding-bottom: 0.5rem;
  }

  .js-enabled .menu-toggle {
    display: inline-flex;
  }

  .js-enabled .site-nav {
    position: fixed;
    z-index: 99;
    inset: var(--header-height) 0 0;
    padding: 1.5rem 1.25rem 3rem;
    background: var(--mist);
    opacity: 0;
    pointer-events: none;
    transform: translateY(-1rem);
    transition: opacity 180ms ease, transform 220ms var(--ease-out);
  }

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

  .site-nav__list {
    flex-wrap: wrap;
    gap: 0.3rem 1.25rem;
  }

  .js-enabled .site-nav__list {
    display: grid;
    align-content: start;
    gap: 0;
  }

  .js-enabled .site-nav li {
    border-bottom: 1px solid var(--structure-blue);
  }

  .js-enabled .site-nav a {
    display: flex;
    min-height: 4rem;
    justify-content: space-between;
    font-family: "Zhigou Serif", "Songti SC", serif;
    font-size: 1.3rem;
  }

  .js-enabled .site-nav a::before {
    order: 2;
    color: var(--academic-purple);
    font-family: "Zhigou Mono", monospace;
    font-size: 0.7rem;
    content: attr(data-nav-link);
    text-transform: uppercase;
  }

  .site-nav a::after {
    display: none;
  }

  .brand__seal {
    width: 2.35rem;
    height: 2.35rem;
  }

  .brand__name {
    font-size: 1.1rem;
  }

  .section-heading,
  .service-item,
  .experience-list article,
  .legal-page__body section,
  .error-page {
    grid-template-columns: 1fr;
  }

  .section-heading {
    gap: 1.5rem;
  }

  .hero h1 {
    font-size: clamp(3rem, 14vw, 4.7rem);
  }

  .hero__principles {
    grid-template-columns: 1fr;
  }

  .hero__principles div {
    display: grid;
    grid-template-columns: 2.5rem 1fr;
    align-items: center;
  }

  .hero__principles dd {
    margin: 0;
  }

  .system-map {
    margin-inline: -0.25rem;
    padding: 0.5rem;
  }

  .system-map__caption {
    padding-inline: 0.5rem;
  }

  .service-item {
    gap: 0.7rem;
  }

  .service-item__index {
    margin-bottom: 0.5rem;
  }

  .service-item ul {
    margin-top: 1rem;
  }

  .advantage-map,
  .delivery-steps {
    grid-template-columns: 1fr;
  }

  .advantage-map article {
    min-height: auto;
  }

  .delivery-steps > li,
  .delivery-steps > li:nth-child(3) {
    min-height: auto;
    border-left: 1px solid var(--structure-blue);
  }

  .delivery-steps h3 {
    margin-top: 2.75rem;
  }

  .experience-list dl div {
    grid-template-columns: 2.75rem 1fr;
  }

  .about__mark {
    width: calc(100% - 1.5rem);
  }

  .contact-card {
    margin-inline: -0.25rem;
  }

  .contact-form__row {
    grid-template-columns: 1fr;
  }

  .site-footer__inner {
    grid-template-columns: 1fr;
  }

  .site-footer__links {
    justify-content: start;
  }

  .legal-page__body section {
    gap: 0.75rem;
  }

  .error-page {
    gap: 2rem;
  }

  .error-page__code {
    font-size: 6rem;
  }
}

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

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

  .js-enabled .system-map__paths path {
    stroke-dashoffset: 0;
  }

  .js-enabled .system-map__nodes,
  .js-enabled .system-map__modules,
  .js-enabled .system-map__seal {
    opacity: 1;
  }
}

@media print {
  .site-header,
  .site-footer,
  .hero__actions,
  .menu-toggle {
    display: none;
  }

  body {
    color: var(--ink);
    background: var(--white);
  }
}