:root {
  --page: #f2efe7;
  --paper: #fffaf0;
  --paper-strong: #ffffff;
  --ink: #1d2420;
  --ink-strong: #0f1613;
  --muted: #66736d;
  --soft: #87928d;
  --line: rgba(25, 34, 30, 0.14);
  --line-strong: rgba(25, 34, 30, 0.24);
  --pine: #1e5d4b;
  --pine-dark: #12382f;
  --orange: #dd6f2a;
  --amber: #f2b64d;
  --blue: #3e7f95;
  --red: #b94d3a;
  --sidebar: #121b17;
  --sidebar-2: #1d2a24;
  --radius: 8px;
  --shadow: 0 22px 54px rgba(24, 29, 27, 0.14);
  --sidebar-w: 264px;
}

* {
  box-sizing: border-box;
}

html {
  scroll-behavior: smooth;
}

body {
  margin: 0;
  color: var(--ink);
  background:
    linear-gradient(90deg, rgba(18, 56, 47, 0.06) 1px, transparent 1px) 0 0 / 34px 34px,
    linear-gradient(180deg, #f6f1e7 0%, #efe8dc 48%, #f5f2eb 100%);
  font-family: "Microsoft YaHei", "PingFang SC", "Noto Sans SC", Arial, sans-serif;
  font-size: 15px;
  line-height: 1.72;
  text-rendering: optimizeLegibility;
}

body::before {
  position: fixed;
  inset: 0;
  z-index: -1;
  pointer-events: none;
  background:
    linear-gradient(135deg, rgba(30, 93, 75, 0.08) 0 18%, transparent 18% 100%),
    linear-gradient(315deg, rgba(221, 111, 42, 0.09) 0 14%, transparent 14% 100%);
  content: "";
}

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

a {
  color: inherit;
  text-decoration: none;
}

p,
h1,
h2,
h3,
figure,
dl,
dd {
  margin: 0;
}

p + p {
  margin-top: 1rem;
}

button,
summary {
  font: inherit;
}

.skip-link {
  position: absolute;
  width: 1px;
  height: 1px;
  overflow: hidden;
  clip: rect(0, 0, 0, 0);
  white-space: nowrap;
}

.skip-link:focus {
  z-index: 1000;
  top: 14px;
  left: 14px;
  width: auto;
  height: auto;
  padding: 0.65rem 0.9rem;
  clip: auto;
  color: #fff;
  background: var(--pine);
  border-radius: var(--radius);
}

.mobile-topbar {
  display: none;
}

.site-shell {
  display: grid;
  grid-template-columns: var(--sidebar-w) minmax(0, 1fr);
  min-height: 100vh;
}

.page-curtain {
  display: none;
}

.side-nav {
  position: sticky;
  top: 0;
  z-index: 30;
  align-self: start;
  display: flex;
  flex-direction: column;
  width: var(--sidebar-w);
  height: 100vh;
  padding: 1rem;
  color: #f7efe0;
  background:
    linear-gradient(180deg, rgba(18, 27, 23, 0.94), rgba(29, 42, 36, 0.98)),
    url("img/tu5.png") center bottom / 170% auto no-repeat;
  border-right: 1px solid rgba(255, 255, 255, 0.1);
  box-shadow: 18px 0 50px rgba(24, 29, 27, 0.12);
}

.side-nav::after {
  position: absolute;
  inset: 0;
  pointer-events: none;
  background: linear-gradient(180deg, rgba(18, 27, 23, 0.7), rgba(18, 27, 23, 0.88));
  content: "";
}

.side-nav > * {
  position: relative;
  z-index: 1;
}

.side-brand {
  display: grid;
  grid-template-columns: 50px minmax(0, 1fr);
  gap: 0.75rem;
  align-items: center;
  padding-bottom: 0.95rem;
  border-bottom: 1px solid rgba(255, 255, 255, 0.16);
}

.side-logo {
  display: grid;
  place-items: center;
  width: 50px;
  height: 50px;
  overflow: hidden;
  background: rgba(255, 255, 255, 0.1);
  border: 1px solid rgba(242, 182, 77, 0.48);
  border-radius: 50%;
}

.side-logo img {
  width: 100%;
  height: 100%;
  object-fit: cover;
  object-position: left center;
}

.side-brand strong {
  display: block;
  color: #fff;
  font-size: 1.04rem;
  line-height: 1.25;
}

.side-brand small {
  display: block;
  margin-top: 0.2rem;
  color: rgba(247, 239, 224, 0.68);
  font-size: 0.78rem;
}

.side-menu {
  display: grid;
  gap: 0.35rem;
  margin-top: 1.15rem;
}

.side-menu a {
  display: flex;
  align-items: center;
  min-height: 39px;
  padding: 0.42rem 0.66rem;
  color: rgba(255, 250, 240, 0.78);
  border: 1px solid transparent;
  border-radius: var(--radius);
  font-size: 0.96rem;
  transition: background 160ms ease, border-color 160ms ease, color 160ms ease, transform 160ms ease;
}

.side-menu a:hover,
.side-menu a.is-active {
  color: #fff;
  background: rgba(255, 255, 255, 0.12);
  border-color: rgba(255, 255, 255, 0.18);
  transform: translateX(3px);
}

.side-facts {
  display: grid;
  gap: 0.65rem;
  margin-top: auto;
  padding-top: 1rem;
}

.side-facts div {
  display: flex;
  justify-content: space-between;
  gap: 0.7rem;
  padding: 0.62rem 0;
  border-top: 1px solid rgba(255, 255, 255, 0.14);
}

.side-facts dt {
  color: rgba(255, 250, 240, 0.58);
  font-size: 0.78rem;
}

.side-facts dd {
  color: #fff;
  font-size: 0.9rem;
  font-weight: 800;
  text-align: right;
}

.side-download,
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  min-height: 42px;
  padding: 0.62rem 0.92rem;
  border: 1px solid transparent;
  border-radius: var(--radius);
  font-weight: 900;
  line-height: 1.2;
  transition: transform 160ms ease, box-shadow 160ms ease, background 160ms ease, border-color 160ms ease;
}

.side-download {
  width: 100%;
  margin-top: 1rem;
  color: #1d170d;
  background: linear-gradient(135deg, #ffd36a, #e98032);
  box-shadow: 0 16px 34px rgba(221, 111, 42, 0.28);
}

.side-download:hover,
.btn:hover {
  transform: translateY(-2px);
}

.site-main {
  min-width: 0;
}

.briefing {
  display: grid;
  grid-template-columns: minmax(0, 1.02fr) minmax(320px, 0.82fr);
  gap: clamp(1.1rem, 2.4vw, 2rem);
  width: min(100% - 48px, 1080px);
  margin-inline: auto;
  padding: clamp(1.6rem, 4vw, 3.5rem) 0 1.35rem;
}

.briefing-copy {
  display: grid;
  align-content: center;
  min-height: 470px;
  padding: clamp(1.3rem, 2.8vw, 2.45rem);
  color: #fdf7eb;
  background:
    linear-gradient(135deg, rgba(18, 56, 47, 0.88), rgba(12, 22, 18, 0.92)),
    url("img/tu6.jpg") center / cover no-repeat;
  border-radius: var(--radius);
  box-shadow: var(--shadow);
}

.section-kicker {
  display: inline-flex;
  width: fit-content;
  margin-bottom: 0.65rem;
  padding: 0.25rem 0.58rem;
  color: var(--pine-dark);
  background: rgba(242, 182, 77, 0.24);
  border: 1px solid rgba(221, 111, 42, 0.26);
  border-radius: 999px;
  font-size: 0.78rem;
  font-weight: 900;
}

.briefing-copy .section-kicker,
.download-ribbon .section-kicker,
.strategy-copy .section-kicker {
  color: #ffe7a6;
  background: rgba(255, 255, 255, 0.12);
  border-color: rgba(255, 255, 255, 0.18);
}

.briefing h1 {
  max-width: 9em;
  color: #fff3c6;
  background: linear-gradient(135deg, #fff8df 0%, #ffd36a 46%, #f08a34 100%);
  -webkit-background-clip: text;
  background-clip: text;
  text-shadow: 0 14px 38px rgba(0, 0, 0, 0.28);
  -webkit-text-fill-color: transparent;
  font-size: clamp(2.25rem, 4.8vw, 4.15rem);
  line-height: 0.98;
  letter-spacing: 0;
  word-break: keep-all;
}

.briefing-lead {
  max-width: 760px;
  margin-top: 1.2rem;
  color: rgba(253, 247, 235, 0.86);
  font-size: clamp(0.95rem, 1.45vw, 1.04rem);
}

.briefing-actions,
.download-actions {
  display: flex;
  flex-wrap: wrap;
  gap: 0.8rem;
  margin-top: 1.2rem;
}

.btn-primary {
  color: #21180b;
  background: linear-gradient(135deg, #ffd36a, #e98032);
  box-shadow: 0 18px 36px rgba(221, 111, 42, 0.25);
}

.btn-secondary {
  color: #fffaf0;
  background: rgba(255, 250, 240, 0.1);
  border-color: rgba(255, 250, 240, 0.26);
}

.btn-dark {
  color: #fff;
  background: var(--pine-dark);
  border-color: rgba(255, 255, 255, 0.16);
}

.btn-large {
  min-height: 46px;
  padding-inline: 1.08rem;
}

.briefing-visual,
.captioned-media,
.systems-media,
.route-frame,
.strategy-media {
  overflow: hidden;
  background: var(--paper);
  border: 1px solid var(--line);
  border-radius: var(--radius);
  box-shadow: var(--shadow);
  transition: transform 180ms ease, box-shadow 180ms ease, border-color 180ms ease;
}

.briefing-visual {
  align-self: start;
}

.briefing-visual img {
  width: 100%;
  aspect-ratio: 4 / 3;
  object-fit: cover;
  transition: transform 420ms ease, filter 220ms ease;
}

figcaption {
  padding: 0.72rem 0.85rem;
  color: var(--muted);
  background: rgba(255, 250, 240, 0.92);
  border-top: 1px solid var(--line);
  font-size: 0.86rem;
}

.quick-board {
  grid-column: 1 / -1;
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 1px;
  overflow: hidden;
  background: var(--line-strong);
  border: 1px solid var(--line-strong);
  border-radius: var(--radius);
}

.quick-board div {
  min-height: 128px;
  padding: 0.95rem;
  background: rgba(255, 250, 240, 0.86);
  transition: background 180ms ease, box-shadow 180ms ease, transform 180ms ease;
}

.quick-board span,
.ledger-row span,
.workflow-list span {
  display: inline-flex;
  margin-bottom: 0.55rem;
  color: var(--orange);
  font-size: 0.76rem;
  font-weight: 900;
}

.quick-board strong {
  display: block;
  color: var(--ink-strong);
  font-size: 0.98rem;
}

.quick-board p {
  margin-top: 0.4rem;
  color: var(--muted);
  font-size: 0.88rem;
}

.content-section {
  width: min(100% - 48px, 1080px);
  margin-inline: auto;
  padding: clamp(1.6rem, 4vw, 3.35rem) 0;
  border-top: 1px solid rgba(25, 34, 30, 0.11);
}

.section-title {
  max-width: 820px;
  margin-bottom: 1.4rem;
}

.section-title-wide {
  display: grid;
  grid-template-columns: minmax(280px, 0.8fr) minmax(320px, 1fr);
  gap: 1.4rem;
  align-items: end;
  max-width: none;
}

.section-title h2,
.strategy-copy h2,
.download-copy h2 {
  color: var(--pine-dark);
  font-size: clamp(1.35rem, 2.2vw, 2.05rem);
  line-height: 1.16;
  letter-spacing: 0;
}

.section-title h2 {
  position: relative;
  display: inline-block;
  padding-bottom: 0.28rem;
}

.section-title h2::after {
  position: absolute;
  right: 0;
  bottom: 0;
  left: 0;
  height: 3px;
  background: linear-gradient(90deg, var(--orange), var(--amber), rgba(30, 93, 75, 0));
  border-radius: 999px;
  content: "";
}

.section-title p,
.strategy-copy p,
.download-copy p,
.text-panel p {
  color: var(--muted);
}

.dossier-grid {
  display: grid;
  grid-template-columns: minmax(0, 1fr) minmax(320px, 0.58fr);
  gap: 1.2rem;
  align-items: start;
}

.text-panel {
  padding: clamp(1rem, 2vw, 1.45rem);
  background: rgba(255, 250, 240, 0.82);
  border: 1px solid var(--line);
  border-radius: var(--radius);
  transition: background 180ms ease, border-color 180ms ease, box-shadow 180ms ease, transform 180ms ease;
}

.captioned-media img,
.systems-media img,
.strategy-media img {
  width: 100%;
  aspect-ratio: 16 / 11;
  object-fit: cover;
  transition: transform 420ms ease, filter 220ms ease;
}

.keyword-rack {
  display: flex;
  flex-wrap: wrap;
  gap: 0.58rem;
  margin-top: 1rem;
}

.keyword-rack span {
  padding: 0.42rem 0.68rem;
  color: var(--pine-dark);
  background: rgba(30, 93, 75, 0.08);
  border: 1px solid rgba(30, 93, 75, 0.18);
  border-radius: 999px;
  font-size: 0.88rem;
  font-weight: 800;
  transition: background 160ms ease, border-color 160ms ease, color 160ms ease, transform 160ms ease;
}

.feature-ledger {
  display: grid;
  border-top: 1px solid var(--line-strong);
}

.ledger-row {
  display: grid;
  grid-template-columns: 60px minmax(160px, 0.42fr) minmax(0, 1fr);
  gap: 0.85rem;
  align-items: start;
  padding: 0.95rem 0;
  border-bottom: 1px solid var(--line-strong);
  transition: background 180ms ease, padding-inline 180ms ease, border-color 180ms ease;
}

.ledger-row h3,
.system-line h3,
.workflow-list h3 {
  color: var(--ink-strong);
  font-size: 1.04rem;
  line-height: 1.32;
}

.ledger-row p,
.system-line p,
.workflow-list p,
.faq-item p,
.check-list {
  color: var(--muted);
}

.systems-board {
  display: grid;
  grid-template-columns: minmax(320px, 0.72fr) minmax(0, 1fr);
  gap: 1.2rem;
  align-items: start;
}

.system-stack {
  display: grid;
  gap: 0.75rem;
}

.system-line {
  padding: 0.85rem 0.92rem;
  background: rgba(255, 250, 240, 0.8);
  border-left: 5px solid var(--pine);
  border-radius: 0 var(--radius) var(--radius) 0;
  box-shadow: 0 14px 32px rgba(24, 29, 27, 0.08);
  transition: background 180ms ease, box-shadow 180ms ease, transform 180ms ease;
}

.system-line:nth-child(2) {
  border-left-color: var(--orange);
}

.system-line:nth-child(3) {
  border-left-color: var(--blue);
}

.system-line:nth-child(4) {
  border-left-color: var(--red);
}

.route-strip {
  display: grid;
  grid-template-columns: 1.08fr 0.92fr 0.92fr;
  gap: 1rem;
}

.route-frame img {
  width: 100%;
  aspect-ratio: 4 / 3;
  object-fit: cover;
  transition: transform 420ms ease, filter 220ms ease;
}

.route-frame:first-child img {
  aspect-ratio: 4 / 5;
}

.guide-block {
  background: linear-gradient(180deg, rgba(255, 250, 240, 0.58), rgba(255, 250, 240, 0));
}

.workflow-list {
  display: grid;
  grid-template-columns: repeat(5, minmax(190px, 1fr));
  gap: 1px;
  margin: 0;
  padding: 0;
  overflow-x: auto;
  list-style: none;
  background: var(--line-strong);
  border: 1px solid var(--line-strong);
  border-radius: var(--radius);
}

.workflow-list li {
  min-height: 230px;
  padding: 0.9rem;
  background: rgba(255, 250, 240, 0.92);
  transition: background 180ms ease, box-shadow 180ms ease, transform 180ms ease;
}

.strategy-panel {
  display: grid;
  grid-template-columns: minmax(320px, 0.82fr) minmax(0, 1fr);
  align-items: stretch;
  overflow: hidden;
  color: #fffaf0;
  background: linear-gradient(135deg, #12221d, #1d3f34);
  border-radius: var(--radius);
  box-shadow: var(--shadow);
}

.strategy-media {
  border: 0;
  border-radius: 0;
  box-shadow: none;
}

.strategy-media img {
  height: 100%;
  min-height: 390px;
  aspect-ratio: auto;
  object-fit: cover;
}

.strategy-copy {
  display: grid;
  align-content: center;
  padding: clamp(1.15rem, 2.4vw, 1.9rem);
}

.strategy-copy h2 {
  color: #fff3c6;
}

.strategy-copy p,
.strategy-copy .check-list {
  color: rgba(255, 250, 240, 0.78);
}

.check-list {
  display: grid;
  gap: 0.72rem;
  margin: 1rem 0 0;
  padding: 0;
  list-style: none;
}

.check-list li {
  position: relative;
  padding-left: 1.45rem;
}

.check-list li::before {
  position: absolute;
  top: 0.68em;
  left: 0;
  width: 0.54rem;
  height: 0.54rem;
  background: var(--amber);
  border-radius: 50%;
  content: "";
}

.download-ribbon {
  display: grid;
  grid-template-columns: minmax(0, 1fr) auto;
  gap: 1.2rem;
  align-items: center;
  width: min(100% - 48px, 1080px);
  margin: clamp(0.85rem, 3.2vw, 1.8rem) auto;
  padding: clamp(1.1rem, 2.4vw, 1.9rem);
  color: #fffaf0;
  background:
    linear-gradient(135deg, rgba(18, 56, 47, 0.93), rgba(185, 77, 58, 0.86)),
    url("img/tu2.png") center / cover no-repeat;
  border-radius: var(--radius);
  box-shadow: var(--shadow);
  transition: box-shadow 180ms ease, transform 180ms ease;
}

.download-copy h2 {
  color: #fff3c6;
}

.download-copy p {
  max-width: 760px;
  color: rgba(255, 250, 240, 0.82);
}

.notice {
  padding-left: 0.85rem;
  border-left: 3px solid var(--amber);
}

.faq-columns {
  columns: 2 340px;
  column-gap: 1rem;
}

.faq-item {
  display: inline-block;
  width: 100%;
  margin: 0 0 1rem;
  padding: 0.85rem;
  background: rgba(255, 250, 240, 0.88);
  border: 1px solid var(--line);
  border-radius: var(--radius);
  break-inside: avoid;
  transition: background 180ms ease, border-color 180ms ease, box-shadow 180ms ease, transform 180ms ease;
}

.faq-item summary {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 1rem;
  color: var(--ink-strong);
  cursor: pointer;
  font-weight: 900;
  list-style: none;
}

.faq-item summary::-webkit-details-marker {
  display: none;
}

.faq-item summary::after {
  flex: 0 0 auto;
  color: var(--orange);
  content: "+";
  font-size: 1.15rem;
}

.faq-item[open] summary::after {
  content: "-";
}

.faq-item p {
  margin-top: 0.75rem;
}

.site-footer {
  display: grid;
  grid-template-columns: minmax(0, 1fr) auto auto;
  gap: 1rem;
  align-items: center;
  margin-left: var(--sidebar-w);
  padding: 1.2rem min(3vw, 2rem);
  color: rgba(255, 250, 240, 0.72);
  background: #121b17;
}

.site-footer strong {
  display: block;
  color: #fff;
}

.site-footer p {
  color: rgba(255, 250, 240, 0.68);
  font-size: 0.9rem;
}

.site-footer nav {
  display: flex;
  flex-wrap: wrap;
  gap: 0.7rem;
}

.site-footer a:hover {
  color: #fff;
}

@media (hover: hover) and (pointer: fine) {
  .btn:hover,
  .side-download:hover {
    box-shadow: 0 18px 38px rgba(221, 111, 42, 0.28);
  }

  .btn-secondary:hover,
  .btn-dark:hover {
    background: rgba(255, 250, 240, 0.18);
    border-color: rgba(255, 250, 240, 0.38);
  }

  .briefing-visual:hover,
  .captioned-media:hover,
  .systems-media:hover,
  .route-frame:hover {
    transform: translateY(-4px);
    border-color: rgba(30, 93, 75, 0.28);
    box-shadow: 0 28px 68px rgba(24, 29, 27, 0.18);
  }

  .briefing-visual:hover img,
  .captioned-media:hover img,
  .systems-media:hover img,
  .route-frame:hover img,
  .strategy-media:hover img {
    transform: scale(1.035);
    filter: saturate(1.06) contrast(1.03);
  }

  .quick-board div:hover,
  .workflow-list li:hover,
  .text-panel:hover,
  .faq-item:hover {
    background: rgba(255, 253, 247, 0.98);
    border-color: rgba(30, 93, 75, 0.24);
    box-shadow: 0 18px 42px rgba(24, 29, 27, 0.1);
    transform: translateY(-3px);
  }

  .keyword-rack span:hover {
    color: #fff;
    background: var(--pine);
    border-color: var(--pine);
    transform: translateY(-2px);
  }

  .ledger-row:hover {
    padding-inline: 0.75rem;
    background: rgba(255, 250, 240, 0.68);
    border-color: rgba(30, 93, 75, 0.2);
  }

  .ledger-row:hover span,
  .workflow-list li:hover span {
    color: var(--pine);
  }

  .system-line:hover {
    background: rgba(255, 253, 247, 0.98);
    box-shadow: 0 18px 44px rgba(24, 29, 27, 0.12);
    transform: translateX(4px);
  }

  .download-ribbon:hover {
    transform: translateY(-3px);
    box-shadow: 0 30px 76px rgba(24, 29, 27, 0.2);
  }

  .faq-item:hover summary {
    color: var(--pine);
  }
}

.reveal {
  opacity: 0;
  transform: translateY(18px);
  transition: opacity 520ms ease, transform 520ms ease;
}

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

.error-page {
  min-height: 100vh;
  display: grid;
  place-items: center;
  padding: 2rem;
}

.error-card {
  width: min(100%, 760px);
  padding: clamp(1.4rem, 4vw, 3rem);
  color: #fffaf0;
  background:
    linear-gradient(135deg, rgba(18, 56, 47, 0.9), rgba(12, 22, 18, 0.93)),
    url("img/tu5.png") center / cover no-repeat;
  border-radius: var(--radius);
  box-shadow: var(--shadow);
}

.error-card h1 {
  color: #fff3c6;
  font-size: clamp(1.9rem, 5.6vw, 3.8rem);
  line-height: 1;
}

.error-card p {
  max-width: 620px;
  margin-top: 1rem;
  color: rgba(255, 250, 240, 0.82);
}

.error-card .briefing-actions {
  margin-top: 1.4rem;
}

@media (max-width: 1100px) {
  :root {
    --sidebar-w: 232px;
  }

  .briefing,
  .content-section,
  .download-ribbon {
    width: min(100% - 34px, 920px);
  }

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

  .briefing-copy {
    min-height: 380px;
  }

  .briefing-visual img {
    aspect-ratio: 16 / 8;
  }

  .dossier-grid,
  .systems-board,
  .strategy-panel {
    grid-template-columns: 1fr;
  }

  .strategy-media img {
    min-height: 0;
    aspect-ratio: 16 / 8;
  }

  .route-strip {
    grid-template-columns: repeat(3, minmax(240px, 1fr));
    overflow-x: auto;
    padding-bottom: 0.3rem;
  }
}

@media (max-width: 820px) {
  body {
    padding-top: 66px;
  }

  .mobile-topbar {
    position: fixed;
    z-index: 80;
    inset: 0 0 auto;
    display: flex;
    align-items: center;
    justify-content: space-between;
    min-height: 66px;
    padding: 0 1rem;
    color: #fffaf0;
    background: rgba(18, 27, 23, 0.96);
    border-bottom: 1px solid rgba(255, 255, 255, 0.12);
  }

  .mobile-brand {
    display: inline-flex;
    align-items: center;
    gap: 0.62rem;
    font-weight: 900;
  }

  .mobile-brand img {
    width: 34px;
    height: 34px;
    object-fit: cover;
    object-position: left center;
    border-radius: 50%;
  }

  .menu-button {
    min-width: 72px;
    min-height: 40px;
    color: #fffaf0;
    background: rgba(255, 255, 255, 0.12);
    border: 1px solid rgba(255, 255, 255, 0.18);
    border-radius: var(--radius);
    font-weight: 900;
  }

  .site-shell {
    display: block;
  }

  .side-nav {
    position: fixed;
    inset: 66px auto 0 0;
    z-index: 70;
    width: min(82vw, 310px);
    height: auto;
    transform: translateX(-105%);
    transition: transform 220ms ease;
  }

  .side-nav.is-open {
    transform: translateX(0);
  }

  .page-curtain {
    position: fixed;
    inset: 66px 0 0;
    z-index: 60;
    display: none;
    background: rgba(10, 16, 14, 0.52);
  }

  .page-curtain.is-open {
    display: block;
  }

  .site-footer {
    grid-template-columns: 1fr;
    margin-left: 0;
  }

  .briefing,
  .content-section,
  .download-ribbon {
    width: min(100% - 24px, 680px);
  }

  .briefing {
    padding-top: 1rem;
  }

  .quick-board {
    grid-template-columns: 1fr;
  }

  .section-title-wide,
  .ledger-row,
  .download-ribbon {
    grid-template-columns: 1fr;
  }

  .ledger-row {
    gap: 0.4rem;
  }

  .route-strip {
    grid-template-columns: 1fr;
    overflow-x: visible;
  }

  .workflow-list {
    grid-template-columns: 1fr;
    overflow-x: visible;
  }

  .workflow-list li {
    min-height: auto;
  }

  .download-actions {
    margin-top: 0;
  }
}

@media (max-width: 540px) {
  .briefing-copy {
    min-height: 0;
    padding: 1.2rem;
  }

  .briefing h1 {
    font-size: clamp(1.85rem, 10.5vw, 2.55rem);
  }

  .briefing-actions,
  .download-actions {
    display: grid;
  }

  .btn {
    width: 100%;
  }

  .section-title h2,
  .strategy-copy h2,
  .download-copy h2 {
    font-size: clamp(1.28rem, 7.2vw, 1.78rem);
  }

  .captioned-media img,
  .systems-media img,
  .strategy-media img,
  .briefing-visual img,
  .route-frame img,
  .route-frame:first-child img {
    aspect-ratio: 4 / 3;
  }

  .faq-columns {
    columns: 1;
  }
}

@media (prefers-reduced-motion: reduce) {
  *,
  *::before,
  *::after {
    scroll-behavior: auto !important;
    transition-duration: 0.01ms !important;
    animation-duration: 0.01ms !important;
    animation-iteration-count: 1 !important;
  }

  .reveal {
    opacity: 1;
    transform: none;
  }
}