:root {
  --blue: #0b4a78;
  --blue-deep: #0b4a78;
  --blue-dark: #082f4d;
  --red: #cc2222;
  --yellow: #f5a000;
  --ink: #171717;
  --ink-soft: #46515a;
  --paper: #f2f4f5;
  --mist: #e8edef;
  --line: #d6dde1;
  --white: #ffffff;
  --content: 1200px;
  --header-height: 76px;
}

* { box-sizing: border-box; }

html {
  scroll-behavior: smooth;
  scroll-padding-top: calc(var(--header-height) + 42px);
}

body {
  margin: 0;
  color: var(--ink);
  background: var(--white);
  font-family: "PingFang SC", "Microsoft YaHei", "Noto Sans CJK SC", Arial, sans-serif;
  line-height: 1.65;
  letter-spacing: 0;
}

body.menu-open { overflow: hidden; }

img { display: block; max-width: 100%; }
a { color: inherit; text-decoration: none; }
button, a { -webkit-tap-highlight-color: transparent; }

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

.skip-link {
  position: fixed;
  top: -80px;
  left: 18px;
  z-index: 1000;
  padding: 10px 14px;
  color: var(--ink);
  background: var(--white);
}

.skip-link:focus { top: 18px; }

.site-header {
  position: sticky;
  top: 0;
  z-index: 80;
  min-height: var(--header-height);
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 30px;
  padding: 0 max(24px, calc((100vw - var(--content)) / 2));
  background: rgba(255, 255, 255, 0.96);
  border-bottom: 1px solid rgba(21, 34, 45, 0.14);
  backdrop-filter: blur(12px);
}

.brand {
  flex: 0 0 auto;
  display: flex;
  align-items: center;
  gap: 12px;
}

.brand > img {
  width: 48px;
  height: 44px;
  object-fit: cover;
  object-position: left center;
}

.brand-copy { display: flex; flex-direction: column; min-width: 0; }
.brand-copy strong { color: var(--ink); font-size: 18px; line-height: 1.25; }
.brand-copy small { margin-top: 3px; color: #68727a; font-size: 9px; font-weight: 700; }

.primary-nav {
  display: flex;
  align-items: center;
  gap: 25px;
  font-size: 14px;
  font-weight: 700;
}

.primary-nav a:not(.nav-cta) {
  padding: 26px 0 22px;
  border-bottom: 3px solid transparent;
}

.primary-nav a:hover:not(.nav-cta),
.primary-nav a.is-active:not(.nav-cta) { border-bottom-color: var(--blue); }

.nav-cta {
  min-height: 42px;
  display: inline-flex;
  align-items: center;
  padding: 8px 16px;
  color: var(--white);
  background: var(--red);
}

.site-tools {
  flex: 0 0 auto;
  display: flex;
  align-items: center;
  gap: 8px;
}

.language-toggle,
.theme-picker summary {
  width: 38px;
  height: 38px;
  display: inline-flex;
  align-items: center;
  justify-content: center;
  padding: 0;
  color: var(--ink);
  background: var(--white);
  border: 1px solid var(--line);
  border-radius: 50%;
  font-size: 11px;
  font-weight: 850;
  line-height: 1;
  cursor: pointer;
}

.language-toggle:hover,
.theme-picker summary:hover { border-color: var(--blue); }

.theme-picker { position: relative; }
.theme-picker summary { list-style: none; }
.theme-picker summary::-webkit-details-marker { display: none; }
.theme-picker summary span { font-size: 18px; font-weight: 500; }

.theme-menu {
  position: absolute;
  top: 46px;
  right: 0;
  z-index: 100;
  width: 158px;
  padding: 6px;
  color: var(--ink);
  background: var(--white);
  border: 1px solid var(--line);
  box-shadow: 0 16px 44px rgba(8, 39, 59, 0.18);
}

.theme-menu button {
  width: 100%;
  min-height: 38px;
  display: grid;
  grid-template-columns: 24px 1fr;
  gap: 8px;
  align-items: center;
  padding: 0 10px;
  color: #687782;
  background: transparent;
  border: 0;
  text-align: left;
  cursor: pointer;
}

.theme-menu button:hover,
.theme-menu button[aria-pressed="true"] {
  color: var(--ink);
  background: var(--paper);
  font-weight: 800;
}

.menu-button {
  width: 46px;
  height: 42px;
  display: none;
  place-content: center;
  gap: 5px;
  padding: 0;
  background: transparent;
  border: 1px solid var(--line);
  cursor: pointer;
}

.menu-button span {
  width: 20px;
  height: 2px;
  display: block;
  background: var(--ink);
  transition: transform 180ms ease, opacity 180ms ease;
}

.menu-button[aria-expanded="true"] span:nth-child(1) { transform: translateY(7px) rotate(45deg); }
.menu-button[aria-expanded="true"] span:nth-child(2) { opacity: 0; }
.menu-button[aria-expanded="true"] span:nth-child(3) { transform: translateY(-7px) rotate(-45deg); }

.hero {
  position: relative;
  min-height: clamp(600px, calc(100svh - 132px), 760px);
  display: flex;
  align-items: flex-end;
  overflow: hidden;
  color: var(--white);
  background: var(--blue-dark) url("assets/hero-bridge-installation.jpg") center 56% / cover no-repeat;
}

.hero::before {
  content: "";
  position: absolute;
  top: 0;
  bottom: 0;
  left: max(24px, calc((100vw - var(--content)) / 2));
  z-index: 2;
  width: 6px;
  background: var(--red);
  border-right: 3px solid var(--yellow);
}

.hero-overlay {
  position: absolute;
  inset: 0;
  background: rgba(10, 24, 33, 0.7);
}

.hero-content {
  position: relative;
  z-index: 2;
  width: min(var(--content), calc(100% - 48px));
  margin: 0 auto;
  padding: 88px 0 82px 34px;
}

.eyebrow {
  margin: 0 0 15px;
  color: #ffd25a;
  font-size: 12px;
  font-weight: 800;
  letter-spacing: 0;
}

.eyebrow.dark { color: var(--blue-deep); }

.hero h1 {
  max-width: 900px;
  margin: 0;
  font-size: 76px;
  line-height: 1.08;
  letter-spacing: 0;
}

.hero-lead {
  margin: 24px 0 0;
  font-size: 32px;
  font-weight: 750;
}

.hero-copy {
  max-width: 680px;
  margin: 14px 0 0;
  color: rgba(255, 255, 255, 0.82);
  font-size: 17px;
}

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

.button {
  min-height: 48px;
  display: inline-flex;
  align-items: center;
  justify-content: center;
  padding: 11px 21px;
  border: 1px solid transparent;
  font-size: 15px;
  font-weight: 750;
}

.button-primary { color: var(--white); background: var(--red); }
.button-primary:hover { background: #ad1d1d; }

.button-secondary {
  color: var(--white);
  background: rgba(6, 30, 50, 0.35);
  border-color: rgba(255, 255, 255, 0.66);
}

.button-secondary:hover { background: rgba(255, 255, 255, 0.12); }

.hero-caption {
  position: absolute;
  right: 18px;
  bottom: 14px;
  z-index: 2;
  margin: 0;
  color: rgba(255, 255, 255, 0.58);
  font-size: 10px;
}

.section { padding: 110px max(24px, calc((100vw - var(--content)) / 2)); }
.section-shell { width: min(var(--content), 100%); margin: 0 auto; }

.section-heading h2,
.contact-section h2,
.image-statement h2 {
  margin: 0;
  font-size: 52px;
  line-height: 1.18;
  letter-spacing: 0;
}

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

.about-layout {
  display: grid;
  grid-template-columns: minmax(260px, 0.8fr) minmax(0, 1.5fr);
  gap: 90px;
}

.about-copy { max-width: 760px; color: var(--ink-soft); font-size: 17px; }
.about-copy p { margin: 0 0 23px; }
.about-copy .lead-copy { color: var(--ink); font-size: 21px; line-height: 1.85; }

.culture-line {
  display: flex;
  flex-wrap: wrap;
  gap: 10px;
  margin-top: 36px;
}

.culture-line span {
  min-width: 112px;
  padding: 10px 18px;
  color: var(--ink);
  background: var(--paper);
  border-left: 4px solid var(--red);
  font-size: 15px;
  font-weight: 800;
}

.image-statement {
  position: relative;
  min-height: 510px;
  display: flex;
  align-items: center;
  overflow: hidden;
  color: var(--white);
}

.image-statement > img {
  position: absolute;
  inset: 0;
  width: 100%;
  height: 100%;
  object-fit: cover;
  object-position: center;
}

.image-statement-overlay { position: absolute; inset: 0; background: rgba(8, 39, 59, 0.72); }

.image-statement-copy {
  position: relative;
  z-index: 2;
  width: min(var(--content), calc(100% - 48px));
  margin: 0 auto;
}

.image-statement-copy > p:last-child {
  margin: 26px 0 0;
  color: #ffd25a;
  font-size: 16px;
  font-weight: 700;
}

.capability-section { background: var(--paper); }

.section-intro-row {
  display: grid;
  grid-template-columns: 1fr minmax(300px, 0.72fr);
  align-items: end;
  gap: 70px;
  margin-bottom: 58px;
}

.section-intro-row > p {
  margin: 0 0 8px;
  color: #667985;
  font-size: 15px;
}

.capability-grid {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  border-top: 1px solid var(--line);
  border-left: 1px solid var(--line);
}

.capability-grid article {
  min-height: 260px;
  padding: 27px;
  background: var(--white);
  border-right: 1px solid var(--line);
  border-bottom: 1px solid var(--line);
  transition: border-color 180ms ease, transform 180ms ease;
}

.capability-grid article:hover {
  border-top: 4px solid var(--red);
  transform: translateY(-4px);
}

.capability-grid span {
  color: var(--red);
  font-size: 13px;
  font-weight: 850;
}

.capability-grid h3 { margin: 54px 0 13px; font-size: 20px; line-height: 1.4; }
.capability-grid p { margin: 0; color: #60717c; font-size: 14px; }

.legal-note {
  margin: 26px 0 0;
  color: #71808a;
  font-size: 12px;
}

.practice-section { color: var(--white); background: #171717; }
.section-intro-row.inverse > p { color: rgba(255, 255, 255, 0.62); }

.project-grid {
  display: grid;
  grid-template-columns: repeat(12, 1fr);
  gap: 15px;
}

.project-grid figure {
  position: relative;
  min-height: 325px;
  grid-column: span 6;
  margin: 0;
  overflow: hidden;
  background: #1b3749;
}

.project-grid .project-feature { min-height: 560px; grid-column: span 12; }

.project-grid img {
  width: 100%;
  height: 100%;
  object-fit: cover;
  transition: transform 500ms ease;
}

.project-grid figure:hover img { transform: scale(1.025); }

.project-grid figcaption {
  position: absolute;
  left: 0;
  right: 0;
  bottom: 0;
  display: flex;
  align-items: end;
  justify-content: space-between;
  gap: 25px;
  padding: 24px 26px;
  background: rgba(6, 27, 42, 0.86);
}

.project-grid figcaption span { color: #ffd25a; font-size: 12px; font-weight: 800; }
.project-grid figcaption strong { max-width: 360px; text-align: right; font-size: 17px; }

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

.resource-layout {
  display: grid;
  grid-template-columns: minmax(280px, 0.8fr) minmax(0, 1.45fr);
  gap: 90px;
}

.resource-intro { max-width: 420px; margin: 25px 0 0; color: #6a7b86; font-size: 14px; }
.resource-groups { border-top: 1px solid var(--line); }

.resource-groups section {
  display: grid;
  grid-template-columns: 145px minmax(190px, 0.75fr) minmax(260px, 1.1fr);
  gap: 24px;
  padding: 31px 0;
  border-bottom: 1px solid var(--line);
}

.resource-index { margin: 0; color: var(--red); font-size: 11px; font-weight: 850; }
.resource-groups h3 { margin: 0; font-size: 20px; line-height: 1.45; }
.resource-groups ul { margin: 0; padding: 0; list-style: none; color: #60717c; font-size: 14px; }
.resource-groups li + li { margin-top: 8px; }
.resource-groups li::before { content: "/"; margin-right: 8px; color: var(--red); font-weight: 800; }
.resource-principles > p:last-child { margin: 0; color: #60717c; font-size: 14px; }

.qualification-section { color: var(--white); background: var(--blue-deep); }

.qualification-layout {
  display: grid;
  grid-template-columns: minmax(280px, 0.8fr) minmax(0, 1.35fr);
  gap: 90px;
}

.qualification-layout .section-heading > p:last-child {
  max-width: 420px;
  margin: 23px 0 0;
  color: rgba(255, 255, 255, 0.68);
}

.qualification-list { margin: 0; border-top: 1px solid rgba(255, 255, 255, 0.34); }

.qualification-list div {
  min-height: 78px;
  display: grid;
  grid-template-columns: 1fr auto;
  align-items: center;
  gap: 30px;
  border-bottom: 1px solid rgba(255, 255, 255, 0.34);
}

.qualification-list dt { font-size: 17px; font-weight: 700; }
.qualification-list dd { margin: 0; color: #ffd25a; font-size: 18px; font-weight: 800; }

.qualification-note {
  margin-top: 34px;
  color: rgba(255, 255, 255, 0.55);
  font-size: 12px;
}

.contact-section {
  padding: 105px max(24px, calc((100vw - var(--content)) / 2));
  background: var(--yellow);
  border-top: 8px solid var(--red);
}

.contact-layout {
  display: grid;
  grid-template-columns: minmax(300px, 0.9fr) minmax(0, 1.15fr);
  align-items: end;
  gap: 90px;
}

.contact-section .eyebrow { color: #6d1a1d; }
.contact-copy > p { max-width: 650px; margin: 0 0 30px; color: #463a19; font-size: 17px; }

.contact-pending {
  display: grid;
  grid-template-columns: 130px 1fr;
  gap: 20px;
  padding: 20px 0;
  border-top: 1px solid rgba(21, 34, 45, 0.35);
  border-bottom: 1px solid rgba(21, 34, 45, 0.35);
}

.contact-pending span { color: #745d20; font-size: 13px; }
.contact-pending strong { font-size: 16px; }

.contact-channels { display: grid; grid-template-columns: repeat(2, minmax(0, 1fr)); gap: 1px; margin-top: 8px; background: rgba(21, 34, 45, 0.35); }
.contact-channel { position: relative; min-height: 132px; display: flex; flex-direction: column; justify-content: center; gap: 5px; padding: 20px; background: var(--yellow); }
.contact-channel-head { display: flex; align-items: center; gap: 9px; color: #745d20; font-size: 13px; }
.contact-channel-head > span:last-child { color: #745d20; font-size: 13px; }
.contact-icon { width: 30px; height: 30px; display: inline-grid; place-items: center; color: var(--blue-deep); background: rgba(255, 255, 255, 0.56); border: 1px solid rgba(21, 34, 45, 0.2); border-radius: 50%; }
.contact-icon svg { width: 17px; height: 17px; fill: none; stroke: currentColor; stroke-linecap: round; stroke-linejoin: round; stroke-width: 1.7; }
.contact-icon-wechat { color: #237a4b; }
.contact-channel strong { font-size: 17px; }
.contact-channel small { color: #604d1b; font-size: 12px; }
.contact-email { width: fit-content; color: inherit; }
.contact-email:hover strong { color: var(--red); }
.wechat-channel { align-items: stretch; }
.wechat-trigger { width: 100%; display: flex; align-items: center; justify-content: space-between; gap: 12px; padding: 0; color: inherit; background: transparent; border: 0; text-align: left; cursor: pointer; }
.wechat-trigger:hover strong { color: var(--red); }
.contact-arrow { color: var(--red); font-size: 20px; line-height: 1; transition: transform 180ms ease; }
.wechat-channel.is-open .contact-arrow { transform: rotate(45deg); }
.wechat-popover { position: absolute; right: 16px; bottom: calc(100% + 14px); z-index: 20; width: min(240px, calc(100vw - 40px)); display: grid; gap: 9px; padding: 13px; color: var(--ink); background: var(--white); border: 1px solid rgba(21, 34, 45, 0.24); box-shadow: 0 18px 45px rgba(21, 34, 45, 0.25); opacity: 0; pointer-events: none; transform: translateY(7px); visibility: hidden; transition: opacity 160ms ease, transform 160ms ease, visibility 160ms ease; }
.wechat-popover::after { content: ""; position: absolute; right: 26px; bottom: -7px; width: 12px; height: 12px; background: var(--white); border-right: 1px solid rgba(21, 34, 45, 0.24); border-bottom: 1px solid rgba(21, 34, 45, 0.24); transform: rotate(45deg); }
.wechat-channel.is-open .wechat-popover { opacity: 1; pointer-events: auto; transform: translateY(0); visibility: visible; }
@media (hover: hover) {
  .wechat-channel:hover .wechat-popover,
  .wechat-channel:focus-within .wechat-popover { opacity: 1; pointer-events: auto; transform: translateY(0); visibility: visible; }
}
.wechat-popover-title { color: var(--blue-deep); font-size: 13px; font-weight: 800; }
.wechat-qr-frame { width: 100%; aspect-ratio: 1; padding: 7px; background: #fff; border: 1px solid rgba(21, 34, 45, 0.18); }
.wechat-qr-frame img { width: 100%; height: 100%; object-fit: contain; }
.wechat-popover small { color: #604d1b; font-size: 11px; line-height: 1.45; }

.site-footer {
  min-height: 146px;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 30px;
  padding: 36px max(24px, calc((100vw - var(--content)) / 2));
  color: var(--white);
  background: #171717;
}

.footer-brand { display: flex; align-items: center; gap: 15px; }
.footer-brand img { width: 48px; height: 43px; object-fit: cover; object-position: left center; background: #fff; }
.footer-brand div { display: flex; flex-direction: column; }
.footer-brand strong { font-size: 17px; }
.footer-brand span { margin-top: 2px; color: rgba(255, 255, 255, 0.52); font-family: Georgia, serif; font-size: 11px; }
.footer-meta { display: flex; align-items: center; gap: 28px; color: rgba(255, 255, 255, 0.58); font-size: 12px; }
.footer-license { color: rgba(255, 255, 255, 0.76); text-decoration: underline; text-underline-offset: 3px; }
.footer-license:hover { color: var(--white); }

.error-page { min-height: 100svh; display: grid; place-items: center; padding: 28px; background: var(--paper); }
.error-page-content { width: min(560px, 100%); padding: 56px; background: var(--white); border-top: 8px solid var(--red); box-shadow: 0 20px 60px rgba(8, 47, 77, 0.12); }
.error-page-content .eyebrow { margin-bottom: 22px; }
.error-code { margin: 0; color: var(--blue-deep); font-size: 92px; font-weight: 850; line-height: 0.95; }
.error-page h1 { margin: 18px 0 12px; font-size: 34px; line-height: 1.25; }
.error-page-content > p:not(.eyebrow):not(.error-code) { margin: 0 0 28px; color: var(--ink-soft); }

@media (max-width: 1080px) {
  .brand-copy strong { font-size: 16px; }
  .brand-copy small { font-size: 8px; }
  .primary-nav { gap: 17px; font-size: 13px; }
  .capability-grid { grid-template-columns: repeat(2, 1fr); }
  .resource-groups section { grid-template-columns: 120px 1fr; }
  .resource-groups section > :last-child { grid-column: 2; }
}

@media (max-width: 900px) {
  :root { --header-height: 68px; }

  .site-header { padding: 0 20px; backdrop-filter: none; }
  .brand img { width: 222px; }
  .menu-button { display: grid; }

  .primary-nav {
    position: fixed;
    inset: calc(32px + var(--header-height)) 0 auto 0;
    min-height: calc(100svh - 32px - var(--header-height));
    display: none;
    flex-direction: column;
    align-items: stretch;
    gap: 0;
    padding: 28px 24px;
    background: rgba(255, 255, 255, 0.99);
    border-top: 1px solid var(--line);
  }

  .primary-nav.is-open { display: flex; }
  .primary-nav a:not(.nav-cta) { padding: 16px 0; border-bottom: 1px solid var(--line); }
  .nav-cta { justify-content: center; margin-top: 22px; }

  .hero { min-height: min(680px, calc(100svh - 100px)); }
  .hero-content { padding: 72px 0 62px; }
  .hero-caption { display: none; }

  .section { padding-top: 82px; padding-bottom: 82px; }
  .about-layout, .resource-layout, .qualification-layout, .contact-layout { grid-template-columns: 1fr; gap: 45px; }
  .section-intro-row { grid-template-columns: 1fr; gap: 25px; }
  .about-copy { max-width: none; }
  .project-grid .project-feature { min-height: 470px; }
  .project-grid figure { min-height: 300px; }
}

@media (max-width: 640px) {
  .site-header { min-height: 64px; gap: 10px; padding-left: 14px; padding-right: 14px; }
  .brand { gap: 9px; }
  .brand > img { width: 41px; height: 38px; }
  .brand-copy { max-width: 160px; }
  .brand-copy strong { display: block; overflow: hidden; font-size: 13px; text-overflow: ellipsis; white-space: nowrap; }
  .brand-copy small { display: none; }
  .menu-button { flex: 0 0 42px; width: 42px; height: 40px; }
  .primary-nav { inset: 94px 0 auto 0; min-height: calc(100svh - 94px); }

  .hero {
    min-height: min(650px, calc(100svh - 94px));
    background-position: 58% center;
  }

  .hero-content { width: calc(100% - 38px); padding: 60px 0 54px; }
  .hero::before { left: 19px; width: 4px; border-right-width: 2px; }
  .hero-content { padding-left: 20px; }
  .hero h1 { font-size: 44px; }
  .hero-lead { max-width: 320px; font-size: 23px; line-height: 1.45; }
  .hero-copy { max-width: 330px; font-size: 15px; }
  .hero-actions { width: 100%; }
  .button { flex: 1 1 145px; padding-left: 15px; padding-right: 15px; }

  .section { padding: 72px 19px; }
  .section-heading h2, .contact-section h2, .image-statement h2 { font-size: 36px; }
  .about-layout { gap: 33px; }
  .about-copy .lead-copy { font-size: 18px; line-height: 1.8; }
  .culture-line span { flex: 1 1 96px; min-width: 0; padding: 9px 12px; font-size: 13px; }

  .image-statement { min-height: 450px; }
  .image-statement-copy { width: calc(100% - 38px); }
  .image-statement h2 br { display: none; }

  .capability-grid { grid-template-columns: 1fr; }
  .capability-grid article { min-height: 225px; }
  .capability-grid h3 { margin-top: 40px; }

  .project-grid { grid-template-columns: 1fr; }
  .project-grid figure, .project-grid .project-feature { min-height: 360px; grid-column: auto; }
  .project-grid figcaption { align-items: start; flex-direction: column; gap: 4px; padding: 18px; }
  .project-grid figcaption strong { text-align: left; font-size: 15px; }

  .resource-groups section { grid-template-columns: 1fr; gap: 12px; }
  .resource-groups section > :last-child { grid-column: auto; }

  .qualification-list div { min-height: 83px; grid-template-columns: 1fr 94px; gap: 12px; }
  .qualification-list dt { font-size: 15px; }
  .qualification-list dd { text-align: right; font-size: 15px; }

  .contact-section { padding: 72px 19px; }
  .contact-layout { gap: 36px; }
  .contact-pending { grid-template-columns: 1fr; gap: 5px; }
  .contact-channels { grid-template-columns: 1fr; }
  .wechat-popover { right: 14px; width: min(240px, calc(100vw - 38px)); }

  .site-footer { align-items: flex-start; flex-direction: column; padding: 34px 19px; }
  .footer-meta { align-items: flex-start; flex-direction: column; gap: 5px; }
  .error-page-content { padding: 38px 26px; }
  .error-code { font-size: 72px; }
}

@media (prefers-reduced-motion: reduce) {
  html { scroll-behavior: auto; }
  *, *::before, *::after { transition-duration: 0.01ms !important; }
}

/* The company palette stays recognizable in dark mode; only surfaces and ink invert. */
html[data-theme="dark"] {
  color-scheme: dark;
  --ink: #edf3f6;
  --ink-soft: #c9d4da;
  --paper: #0d171f;
  --mist: #172630;
  --line: #31434f;
  --white: #edf3f6;
}

html[data-theme="dark"] body { background: var(--paper); }
html[data-theme="dark"] .site-header {
  background: rgba(13, 23, 31, 0.96);
  border-bottom-color: rgba(237, 243, 246, 0.16);
}
html[data-theme="dark"] .primary-nav {
  background: rgba(13, 23, 31, 0.99);
  border-top-color: var(--line);
}
html[data-theme="dark"] .primary-nav a:not(.nav-cta) { border-bottom-color: var(--line); }
html[data-theme="dark"] .brand-copy strong { color: var(--ink); }
html[data-theme="dark"] .brand-copy small { color: #9fb0ba; }
html[data-theme="dark"] .language-toggle,
html[data-theme="dark"] .theme-picker summary {
  color: var(--ink);
  background: #13232d;
  border-color: #405460;
}
html[data-theme="dark"] .skip-link { background: var(--paper); }
html[data-theme="dark"] .about-section,
html[data-theme="dark"] .resource-section {
  background: var(--paper);
  border-color: var(--line);
}
html[data-theme="dark"] .section-intro-row > p,
html[data-theme="dark"] .capability-grid p,
html[data-theme="dark"] .legal-note,
html[data-theme="dark"] .resource-intro,
html[data-theme="dark"] .resource-groups ul,
html[data-theme="dark"] .resource-principles > p:last-child { color: #aebdc5; }
html[data-theme="dark"] .about-copy { color: var(--ink-soft); }
html[data-theme="dark"] .about-copy .lead-copy { color: var(--ink); }
html[data-theme="dark"] .culture-line span,
html[data-theme="dark"] .capability-grid article { background: #13232d; }
html[data-theme="dark"] .capability-grid,
html[data-theme="dark"] .capability-grid article { border-color: var(--line); }
html[data-theme="dark"] .resource-groups,
html[data-theme="dark"] .resource-groups section { border-color: var(--line); }
html[data-theme="dark"] .qualification-section { background: #0b4a78; }
html[data-theme="dark"] .theme-menu { background: #13232d; border-color: #405460; }
html[data-theme="dark"] .theme-menu button { color: #aebdc5; }
html[data-theme="dark"] .theme-menu button:hover,
html[data-theme="dark"] .theme-menu button[aria-pressed="true"] { color: var(--ink); background: #1b303c; }

@media (max-width: 1080px) {
  .site-tools { gap: 6px; }
  .primary-nav { gap: 15px; }
}

@media (max-width: 900px) {
  .site-tools { margin-left: auto; }
  .theme-menu { top: 46px; }
}

@media (max-width: 640px) {
  .site-tools { gap: 6px; }
  .language-toggle,
  .theme-picker summary { width: 34px; height: 34px; }
  .theme-menu { top: 42px; }
}