:root {
  color-scheme: light;
  --paper: #f2f7f5;
  --paper-deep: #dfece8;
  --card: #fbfefd;
  --ink: #18302d;
  --muted: #5f716c;
  --line: #b7cbc5;
  --qingju: #14d0b4;
  --qingju-dark: #006f63;
  --sky: #2f7278;
  --leaf: #4f7658;
  --citrus: #f2b94b;
  --citrus-dark: #8a5a00;
  --max: 1180px;
  --page-gutter: 24px;
  --shadow: 0 18px 48px rgba(18, 68, 60, 0.1);
}

* {
  box-sizing: border-box;
}

html {
  scroll-behavior: smooth;
  scroll-padding-top: 100px;
}

body {
  margin: 0;
  min-width: 320px;
  color: var(--ink);
  background:
    radial-gradient(circle at 90% 4%, rgba(20, 208, 180, 0.14), transparent 24rem),
    var(--paper);
  font-family:
    Inter, ui-sans-serif, system-ui, -apple-system, BlinkMacSystemFont, "PingFang SC",
    "Noto Sans CJK SC", "Microsoft YaHei", sans-serif;
  text-rendering: optimizeLegibility;
}

a {
  color: inherit;
}

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

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

.skip-link {
  position: fixed;
  z-index: 100;
  top: 12px;
  left: 12px;
  padding: 12px 16px;
  color: #fff;
  background: var(--sky);
  transform: translateY(-180%);
}

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

.shell {
  width: min(calc(100% - 2 * var(--page-gutter)), var(--max));
  margin: 0 auto;
}

.site-header {
  position: sticky;
  z-index: 20;
  top: 0;
  border-bottom: 1px solid rgba(183, 203, 197, 0.82);
  background: rgba(242, 247, 245, 0.94);
  backdrop-filter: blur(12px);
}

.header-inner {
  position: relative;
  display: grid;
  grid-template-columns: 1fr auto 1fr;
  align-items: center;
  width: min(calc(100% - 2 * var(--page-gutter)), var(--max));
  min-height: 78px;
  margin: 0 auto;
}

.brand {
  display: inline-flex;
  align-items: center;
  gap: 11px;
  width: max-content;
  min-height: 44px;
  font-size: 0.78rem;
  font-weight: 750;
  letter-spacing: 0.06em;
  text-decoration: none;
}

.brand-logo {
  display: block;
  width: 38px;
  height: auto;
  flex: 0 0 auto;
}

.primary-nav {
  display: flex;
  align-items: center;
  gap: 34px;
}

.primary-nav a {
  display: inline-flex;
  align-items: center;
  min-height: 44px;
  color: #38534e;
  font-size: 0.83rem;
  text-decoration: none;
}

.primary-nav a:hover {
  color: var(--qingju-dark);
}

.context-switcher {
  position: relative;
  justify-self: end;
}

.context-switcher summary {
  display: flex;
  align-items: center;
  gap: 10px;
  min-height: 44px;
  padding: 10px 13px;
  border: 1px solid var(--line);
  border-radius: 7px;
  background: var(--card);
  cursor: pointer;
  list-style: none;
  font-size: 0.75rem;
}

.context-switcher summary::-webkit-details-marker {
  display: none;
}

.context-switcher summary::after {
  content: "↓";
  margin-left: 2px;
  color: var(--muted);
}

.context-switcher[open] summary::after {
  content: "↑";
}

.context-switcher summary span {
  color: var(--muted);
}

.context-switcher summary strong {
  font-weight: 700;
}

.context-switcher nav {
  position: absolute;
  top: calc(100% + 10px);
  right: 0;
  width: 224px;
  overflow: hidden;
  border: 1px solid var(--line);
  border-radius: 9px;
  background: var(--card);
  box-shadow: var(--shadow);
}

.context-switcher nav a {
  display: flex;
  gap: 14px;
  padding: 14px 16px;
  border-bottom: 1px solid #d7e4e0;
  font-size: 0.82rem;
  text-decoration: none;
}

.context-switcher nav a:last-child {
  border-bottom: 0;
}

.context-switcher nav a:hover {
  background: #e7f1ee;
}

.context-switcher nav span {
  color: var(--qingju-dark);
  font-size: 0.75rem;
}

.hero {
  display: grid;
  grid-template-columns: minmax(0, 1.55fr) minmax(320px, 0.7fr);
  gap: clamp(56px, 8vw, 120px);
  align-items: center;
  min-height: 760px;
  padding: 104px 0 116px;
}

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

h1 {
  max-width: 10.5em;
  margin-bottom: 34px;
  font-size: clamp(3.25rem, 6.1vw, 6rem);
  font-weight: 680;
  letter-spacing: -0.04em;
  line-height: 0.98;
}

h1,
h2 {
  text-wrap: balance;
}

h1 span {
  color: var(--qingju);
}

.hero-intro {
  max-width: 43rem;
  margin-bottom: 34px;
  color: #38534e;
  font-size: clamp(1.05rem, 1.35vw, 1.22rem);
  line-height: 1.9;
}

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

.button {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  min-height: 48px;
  padding: 0 19px;
  border-radius: 6px;
  font-size: 0.86rem;
  font-weight: 750;
  text-decoration: none;
}

.button-primary {
  color: #fff;
  background: var(--ink);
}

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

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

.button-text:hover {
  color: var(--qingju-dark);
}

.now-card {
  padding: 28px;
  border: 1px solid var(--ink);
  border-radius: 12px;
  background: var(--card);
  box-shadow: 14px 14px 0 var(--citrus);
}

.now-heading {
  display: flex;
  align-items: center;
  justify-content: space-between;
  margin-bottom: 32px;
}

.now-heading p,
.now-heading span {
  margin: 0;
  font-size: 0.75rem;
  font-weight: 800;
  letter-spacing: 0.12em;
}

.now-heading p {
  color: var(--qingju-dark);
}

.now-heading span {
  padding: 6px 8px;
  background: #d9f4ed;
  color: #285c52;
}

.now-card h2 {
  margin-bottom: 34px;
  font-size: clamp(1.6rem, 2.5vw, 2.25rem);
  font-weight: 650;
  letter-spacing: -0.04em;
  line-height: 1.2;
}

.now-card ol {
  margin: 0;
  padding: 0;
  list-style: none;
}

.now-card li {
  border-top: 1px solid var(--line);
}

.now-link {
  display: grid;
  grid-template-columns: 34px 1fr auto;
  gap: 10px;
  align-items: start;
  min-height: 72px;
  padding: 18px 0;
  text-decoration: none;
}

.now-link > span {
  padding-top: 3px;
  color: var(--qingju-dark);
  font-size: 0.75rem;
}

.now-link i {
  color: var(--qingju-dark);
  font-size: 1rem;
  font-style: normal;
  transition: transform 160ms ease;
}

.now-link:hover strong,
.now-link:focus-visible strong {
  color: var(--qingju-dark);
}

.now-link:hover i,
.now-link:focus-visible i {
  transform: translate(3px, 3px);
}

.now-card strong,
.now-card small {
  display: block;
}

.now-card strong {
  margin-bottom: 6px;
  font-size: 0.95rem;
}

.now-card small {
  color: var(--muted);
  line-height: 1.5;
}

.sharing-section {
  padding: 112px 0;
  border-top: 1px solid var(--line);
  border-bottom: 1px solid var(--line);
  background: var(--card);
}

.section-heading h2,
.contact-card h2 {
  margin-bottom: 0;
  font-size: clamp(2.35rem, 4.6vw, 4.6rem);
  font-weight: 650;
  letter-spacing: -0.04em;
  line-height: 1.05;
}

.split-heading {
  display: grid;
  grid-template-columns: minmax(0, 1.35fr) minmax(280px, 0.65fr);
  gap: clamp(48px, 9vw, 128px);
  align-items: end;
}

.split-heading > p,
.section-summary {
  margin-bottom: 0;
  color: var(--muted);
  font-size: 1rem;
  line-height: 1.85;
}

.practice-section {
  padding: 130px 0 138px;
  border-top: 1px solid var(--line);
  border-bottom: 1px solid var(--line);
  background: var(--paper-deep);
}

.practice-section > .shell > .section-heading {
  display: block;
}

.project-map {
  position: relative;
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 22px;
  margin-top: 76px;
}

.project-map::before {
  position: absolute;
  top: 50%;
  right: 5%;
  left: 5%;
  z-index: -1;
  height: 2px;
  background: var(--ink);
  content: "";
}

.project-card {
  min-height: 430px;
  padding: 28px;
  border: 1px solid var(--ink);
  border-top-width: 8px;
  border-radius: 8px;
  background: var(--card);
  box-shadow: 8px 8px 0 rgba(34, 35, 31, 0.08);
}

.project-knowledge {
  border-top-color: var(--leaf);
}

.project-control {
  border-top-color: var(--sky);
}

.project-robot {
  border-top-color: var(--qingju);
}

.project-meta {
  display: flex;
  justify-content: space-between;
  margin-bottom: 54px;
  color: var(--muted);
  font-size: 0.75rem;
}

.project-meta small {
  font-size: inherit;
}

.project-meta span {
  color: var(--ink);
  font-weight: 800;
  letter-spacing: 0.12em;
}

.project-card h3 {
  margin-bottom: 18px;
  font-size: 1.55rem;
  letter-spacing: -0.035em;
}

.project-card > p {
  min-height: 100px;
  margin-bottom: 28px;
  color: var(--muted);
  line-height: 1.75;
}

.project-card dl {
  margin: 0;
}

.project-card dl div {
  display: grid;
  grid-template-columns: 54px 1fr;
  gap: 8px;
  padding: 13px 0;
  border-top: 1px solid var(--line);
  font-size: 0.78rem;
  line-height: 1.55;
}

.project-card dt {
  color: var(--qingju-dark);
  font-weight: 750;
}

.project-card dd {
  margin: 0;
}

.relationship-note {
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 13px;
  margin-top: 46px;
  color: var(--muted);
  font-size: 0.8125rem;
}

.relationship-note span {
  padding: 9px 12px;
  border: 1px solid var(--line);
  background: var(--card);
  color: var(--ink);
  font-weight: 700;
}

.relationship-note i {
  font-style: normal;
}

.relationship-note i::after {
  content: " →";
  color: var(--qingju-dark);
}

.story-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 22px;
  margin-top: 74px;
}

.story-card {
  padding: 0 0 22px;
  border-bottom: 2px solid var(--ink);
}

.story-card-link {
  display: block;
  color: inherit;
  text-decoration: none;
}

.story-card-link .story-cover {
  transition:
    transform 220ms cubic-bezier(0.16, 1, 0.3, 1),
    box-shadow 220ms cubic-bezier(0.16, 1, 0.3, 1);
}

.story-card-link:hover .story-cover {
  transform: translateY(-5px);
  box-shadow: 0 18px 30px rgba(18, 68, 60, 0.14);
}

.story-card-link:hover h3 {
  color: var(--qingju-dark);
}

.story-cover {
  overflow: hidden;
  aspect-ratio: 16 / 9;
  margin: 0 0 24px;
  border: 1px solid var(--ink);
  background: var(--paper-deep);
}

.story-cover img {
  display: block;
  width: 100%;
  height: 100%;
  object-fit: cover;
}

.story-status {
  margin-bottom: 12px;
  color: var(--qingju-dark);
  font-size: 0.75rem;
  font-weight: 750;
  letter-spacing: 0.08em;
}

.story-card h3 {
  margin-bottom: 13px;
  font-size: 1.42rem;
  letter-spacing: -0.035em;
}

.story-card-link > p:last-child {
  margin-bottom: 0;
  color: var(--muted);
  line-height: 1.7;
}

.sharing-more {
  display: flex;
  flex-wrap: wrap;
  gap: 18px 24px;
  align-items: center;
  margin-top: 48px;
}

.sharing-more p {
  margin: 0;
  color: var(--muted);
  font-size: 0.78rem;
  font-weight: 700;
  letter-spacing: 0.04em;
}

.showcase-home-section {
  padding: 112px 0;
  border-bottom: 1px solid var(--line);
  background: var(--paper-deep);
}

.showcase-home-layout {
  display: grid;
  grid-template-columns: minmax(0, 1.05fr) minmax(320px, 0.65fr);
  gap: clamp(48px, 9vw, 130px);
  align-items: center;
}

.showcase-home-layout h2 {
  margin-bottom: 24px;
  font-size: clamp(2.35rem, 4.8vw, 4.8rem);
  font-weight: 650;
  letter-spacing: -0.04em;
  line-height: 1.04;
}

.showcase-home-layout > div > p:not(.stats-kicker) {
  max-width: 44rem;
  color: var(--muted);
  line-height: 1.85;
}

.showcase-home-card {
  position: relative;
  display: flex;
  min-height: 360px;
  overflow: hidden;
  flex-direction: column;
  justify-content: flex-start;
  padding: 28px;
  border: 2px solid var(--ink);
  border-radius: 14px;
  color: var(--ink);
  background: var(--card) url("./assets/showcase/jian-shan-assembled.png") center / cover no-repeat;
  box-shadow: 12px 12px 0 var(--citrus);
  text-decoration: none;
  transition: transform 180ms ease;
}

.showcase-home-card:hover { transform: translateY(-5px); }
.showcase-home-card span {
  align-self: flex-start;
  padding: 9px 11px;
  border: 1px solid var(--ink);
  background: rgba(247, 250, 249, 0.92);
  font-size: 0.72rem;
  font-weight: 800;
  letter-spacing: 0.08em;
}
@media (prefers-reduced-motion: reduce) {
  .story-card-link .story-cover {
    transition: none;
  }
}

.contact-section {
  padding: 20px 0 112px;
  background: var(--card);
}

.contact-card {
  display: grid;
  grid-template-columns: 1.15fr 0.7fr;
  gap: clamp(48px, 9vw, 130px);
  align-items: end;
  padding: clamp(34px, 6vw, 72px);
  border: 2px solid var(--ink);
  background: var(--citrus);
  box-shadow: 12px 12px 0 var(--ink);
}

.contact-card h2 {
  margin-bottom: 24px;
  font-size: clamp(2.2rem, 4.5vw, 4.2rem);
}

.contact-card > div > p:last-child {
  max-width: 42rem;
  margin-bottom: 0;
  color: var(--ink);
  line-height: 1.75;
}

.contact-actions .button {
  width: 100%;
}

.douyin-line {
  margin-top: 26px;
  padding-top: 20px;
  border-top: 1px solid rgba(24, 48, 45, 0.5);
}

.douyin-line span,
.douyin-line strong {
  display: block;
}

.douyin-line span {
  margin-bottom: 7px;
  font-size: 0.72rem;
}

.douyin-line strong {
  font-size: 1.05rem;
}

.site-footer {
  border-top: 1px solid var(--line);
  color: var(--ink);
  background: #cee5df;
}

.site-stats {
  display: grid;
  grid-template-columns: minmax(0, 1.2fr) minmax(420px, 1fr);
  gap: clamp(48px, 8vw, 112px);
  align-items: end;
  padding-top: 72px;
  padding-bottom: 62px;
  border-bottom: 1px solid rgba(24, 48, 45, 0.18);
}

.stats-kicker {
  margin-bottom: 20px;
  color: var(--qingju-dark);
  font-size: 0.72rem;
  font-weight: 800;
  letter-spacing: 0.12em;
}

.stats-copy h2 {
  max-width: 16em;
  margin-bottom: 16px;
  font-size: clamp(2rem, 3.5vw, 3.6rem);
  font-weight: 680;
  letter-spacing: -0.035em;
  line-height: 1.05;
}

.stats-note {
  max-width: 38rem;
  margin-bottom: 0;
  color: #405b55;
  font-size: 0.82rem;
  line-height: 1.75;
}

.stats-values {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  margin: 0;
  border-top: 1px solid rgba(24, 48, 45, 0.28);
}

.stats-values div {
  min-width: 0;
  padding: 22px 16px 0 0;
}

.stats-values div + div {
  padding-left: 16px;
  border-left: 1px solid rgba(24, 48, 45, 0.18);
}

.stats-values dt {
  margin-bottom: 10px;
  color: var(--muted);
  font-size: 0.68rem;
  letter-spacing: 0.08em;
}

.stats-values dd {
  margin: 0;
  color: var(--qingju-dark);
  font-size: clamp(1.8rem, 3vw, 2.8rem);
  font-weight: 760;
  letter-spacing: -0.04em;
  line-height: 1;
  font-variant-numeric: tabular-nums;
}

.stats-status {
  grid-column: 2;
  margin: 14px 0 0;
  color: var(--muted);
  font-size: 0.66rem;
  letter-spacing: 0.06em;
}

.site-stats[data-ready="unavailable"] .stats-values dd {
  color: var(--muted);
}

.footer-meta {
  display: grid;
  grid-template-columns: 1fr auto;
  gap: 30px;
  align-items: center;
  min-height: 108px;
  font-size: 0.75rem;
  letter-spacing: 0.06em;
}

.footer-links {
  display: flex;
  flex-wrap: wrap;
  gap: 8px 24px;
  align-items: center;
  justify-content: flex-end;
}

.site-footer p {
  margin: 0;
}

.site-footer a {
  display: inline-flex;
  align-items: center;
  min-height: 44px;
  justify-self: end;
  text-decoration: none;
}

@media (max-width: 920px) {
  .header-inner {
    grid-template-columns: 1fr auto;
  }

  .primary-nav {
    display: none;
  }

  .hero,
  .split-heading,
  .practice-section > .shell > .section-heading,
  .showcase-home-layout,
  .contact-card {
    grid-template-columns: 1fr;
  }

  .hero {
    min-height: auto;
    padding: 88px 0 106px;
  }

  .hero-copy {
    max-width: 760px;
  }

  .now-card {
    max-width: 650px;
  }

  .project-map {
    grid-template-columns: 1fr;
    max-width: 720px;
  }

  .project-map::before {
    display: none;
  }

  .project-card {
    min-height: auto;
  }

  .project-card > p {
    min-height: auto;
  }

  .relationship-note {
    flex-wrap: wrap;
    justify-content: flex-start;
  }

  .contact-card {
    align-items: start;
  }

  .contact-actions {
    max-width: 520px;
  }
}

@media (max-width: 680px) {
  :root {
    --page-gutter: 16px;
  }

  .shell,
  .header-inner {
    width: min(calc(100% - 2 * var(--page-gutter)), var(--max));
  }

  .site-header {
    position: static;
  }

  .header-inner {
    min-height: 70px;
  }

  .brand {
    font-size: 0.75rem;
  }

  .brand-logo {
    width: 34px;
  }

  .context-switcher summary span {
    display: none;
  }

  .hero {
    gap: 64px;
    padding: 72px 0 84px;
  }

  h1 {
    font-size: clamp(2.75rem, 12.5vw, 3.5rem);
  }

  .hero-intro {
    font-size: 1rem;
  }

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

  .button {
    width: 100%;
  }

  .now-card {
    margin-right: 9px;
    padding: 22px;
    box-shadow: 9px 9px 0 var(--citrus);
  }

  .sharing-section {
    padding: 84px 0;
  }

  .showcase-home-section {
    padding: 84px 0;
  }

  .showcase-home-card {
    min-height: 300px;
    margin-right: 9px;
    box-shadow: 9px 9px 0 var(--citrus);
  }

  .section-heading h2,
  .showcase-home-layout h2,
  .contact-card h2 {
    font-size: clamp(2.25rem, 11.5vw, 3.5rem);
  }

  .practice-section {
    padding: 92px 0;
  }

  .project-map,
  .story-grid {
    grid-template-columns: 1fr;
    margin-top: 52px;
  }

  .relationship-note {
    display: grid;
    grid-template-columns: 1fr;
  }

  .relationship-note i::after {
    content: " ↓";
  }

  .story-grid {
    gap: 48px;
  }

  .contact-section {
    padding-bottom: 86px;
  }

  .contact-card {
    width: min(calc(100% - 40px), var(--max));
    padding: 30px 24px;
    box-shadow: 8px 8px 0 var(--ink);
  }

  .site-stats {
    grid-template-columns: 1fr;
    gap: 36px;
    padding-top: 54px;
    padding-bottom: 46px;
  }

  .stats-status {
    grid-column: 1;
  }

  .footer-meta {
    grid-template-columns: 1fr;
    gap: 12px;
    padding: 28px 0;
  }

  .footer-links {
    justify-content: flex-start;
  }

  .site-footer a {
    justify-self: start;
  }
}

@media (max-width: 560px) {
  .stats-copy h2 {
    font-size: 2.35rem;
  }

  .stats-values {
    grid-template-columns: 1fr;
  }

  .stats-values div,
  .stats-values div + div {
    display: grid;
    grid-template-columns: 1fr auto;
    align-items: end;
    padding: 18px 0;
    border-left: 0;
    border-bottom: 1px solid rgba(183, 203, 197, 0.28);
  }

  .stats-values dt {
    margin-bottom: 0;
  }

  .stats-values dd {
    font-size: 2rem;
  }
}

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