:root {
  --text: #11161b;
  --muted: #65717b;
  --line: rgba(17, 22, 27, 0.12);
  --surface: #f4f7f6;
  --white: #ffffff;
  --green: #167047;
  --gold: #c69a4a;
  --ink: #071014;
  --blue: #071a28;
}

* {
  box-sizing: border-box;
}

html {
  scroll-behavior: smooth;
}

body {
  margin: 0;
  color: var(--text);
  background: var(--white);
  font-family: "Inter", "PingFang SC", "Microsoft YaHei", Arial, sans-serif;
  letter-spacing: 0;
}

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

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

.detail-header {
  position: fixed;
  inset: 0 0 auto;
  z-index: 20;
  display: flex;
  align-items: center;
  justify-content: space-between;
  height: 64px;
  padding: 0 40px;
  color: var(--white);
  background: rgba(7, 16, 20, 0.16);
  border-bottom: 1px solid rgba(255, 255, 255, 0.12);
  backdrop-filter: blur(18px);
  transition: background 0.25s ease, color 0.25s ease, border-color 0.25s ease;
}

.detail-header.is-scrolled {
  color: var(--text);
  background: rgba(255, 255, 255, 0.94);
  border-color: var(--line);
}

.detail-brand {
  display: inline-flex;
  align-items: center;
  min-width: 166px;
  height: 40px;
}

.detail-logo {
  width: 146px;
  height: auto;
}

.detail-logo-dark {
  display: none;
}

.detail-header.is-scrolled .detail-logo-dark {
  display: block;
}

.detail-header.is-scrolled .detail-logo-light {
  display: none;
}

.detail-nav {
  display: flex;
  gap: 26px;
  font-size: 14px;
}

.drone-hero {
  position: relative;
  min-height: 100vh;
  display: grid;
  align-items: end;
  padding: 120px 8vw 88px;
  color: var(--white);
  overflow: hidden;
}

.drone-hero::before {
  content: "";
  position: absolute;
  inset: 0;
  z-index: 1;
  background:
    linear-gradient(180deg, rgba(5, 12, 16, 0.12), rgba(5, 12, 16, 0.82)),
    linear-gradient(90deg, rgba(5, 12, 16, 0.82), rgba(5, 12, 16, 0.18));
}

.drone-hero-media {
  position: absolute;
  inset: 0;
  background:
    linear-gradient(120deg, rgba(4, 16, 22, 0.25), rgba(4, 16, 22, 0)),
    url("assets/brochure/page-27-image-0.jpg") center / cover;
  transform: scale(1.03);
}

.drone-hero-content,
.hero-panel {
  position: relative;
  z-index: 2;
}

.eyebrow {
  margin: 0 0 18px;
  color: var(--gold);
  font-size: 13px;
  font-weight: 850;
  text-transform: uppercase;
}

.drone-hero h1 {
  width: min(940px, 100%);
  margin: 0;
  font-size: clamp(42px, 7.6vw, 90px);
  line-height: 1.04;
}

.drone-hero-content p:last-child {
  width: min(760px, 100%);
  margin: 24px 0 0;
  color: rgba(255, 255, 255, 0.82);
  font-size: clamp(17px, 2vw, 21px);
  line-height: 1.8;
}

.hero-panel {
  width: min(580px, 100%);
  margin-top: 48px;
  padding: 22px 26px;
  background: rgba(255, 255, 255, 0.1);
  border: 1px solid rgba(255, 255, 255, 0.2);
  backdrop-filter: blur(14px);
}

.hero-panel span {
  color: var(--gold);
  font-size: 12px;
  font-weight: 850;
  text-transform: uppercase;
}

.hero-panel strong {
  display: block;
  margin-top: 8px;
  font-size: clamp(20px, 3vw, 30px);
}

.topic-bar {
  position: sticky;
  top: 64px;
  z-index: 12;
  display: grid;
  grid-template-columns: repeat(13, minmax(0, 1fr));
  gap: 1px;
  padding: 0 8vw;
  background: rgba(255, 255, 255, 0.92);
  border-bottom: 1px solid var(--line);
  backdrop-filter: blur(16px);
}

.topic-bar a {
  display: grid;
  place-items: center;
  gap: 3px;
  min-height: 62px;
  padding: 8px 6px;
  color: rgba(17, 22, 27, 0.62);
  font-size: 11px;
  font-weight: 750;
  text-align: center;
  background: rgba(17, 22, 27, 0.035);
}

.topic-bar span {
  color: rgba(17, 22, 27, 0.36);
  font-weight: 900;
}

.topic-bar a.is-active {
  color: var(--white);
  background: var(--green);
}

.topic-bar a.is-active span {
  color: rgba(255, 255, 255, 0.7);
}

.section {
  padding: 112px 8vw;
}

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

.section-heading {
  max-width: 980px;
  margin-bottom: 48px;
}

.section-heading h2,
.data-copy h2 {
  margin: 0;
  font-size: clamp(32px, 4.8vw, 62px);
  line-height: 1.12;
}

.section-heading p,
.data-copy p {
  max-width: 780px;
  color: var(--muted);
  line-height: 1.85;
  font-size: 17px;
}

.dark .section-heading p {
  color: rgba(255, 255, 255, 0.72);
}

.product-stack {
  display: grid;
  gap: 30px;
}

.product-row {
  display: grid;
  grid-template-columns: minmax(300px, 0.95fr) minmax(0, 1.05fr);
  gap: 0;
  min-height: 360px;
  background: var(--surface);
  border: 1px solid var(--line);
}

.product-media {
  display: grid;
  place-items: center;
  min-height: 360px;
  padding: 34px;
  background: radial-gradient(circle at 30% 15%, #17334d, #06111a 58%, #020609);
}

.product-media img {
  width: min(560px, 100%);
  max-height: 300px;
  object-fit: contain;
}

.product-media-wide {
  background: linear-gradient(135deg, #121719, #243333);
}

.product-copy {
  display: flex;
  flex-direction: column;
  justify-content: center;
  padding: 46px;
}

.stage {
  margin: 0 0 10px;
  color: var(--text);
  font-size: 18px;
  font-weight: 800;
}

.product-copy h3 {
  width: fit-content;
  margin: 0 0 22px;
  padding: 4px 12px;
  color: var(--white);
  background: var(--green);
  font-size: clamp(24px, 3vw, 34px);
  line-height: 1.2;
}

.product-copy p:not(.stage) {
  margin: 0;
  color: var(--text);
  font-size: 18px;
  line-height: 1.75;
}

.tags,
.spec-grid {
  display: flex;
  flex-wrap: wrap;
  gap: 10px;
  margin-top: 24px;
}

.tags span,
.spec-grid span {
  padding: 8px 11px;
  color: var(--green);
  background: rgba(22, 112, 71, 0.1);
  border: 1px solid rgba(22, 112, 71, 0.18);
  font-size: 13px;
  font-weight: 750;
}

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

.simulation-section {
  background:
    linear-gradient(135deg, rgba(6, 15, 20, 0.96), rgba(10, 31, 33, 0.96)),
    url("assets/brochure/page-47-image-0.jpg") center / cover;
}

.sim-grid {
  display: grid;
  grid-template-columns: repeat(3, minmax(0, 1fr));
  gap: 1px;
  background: rgba(255, 255, 255, 0.16);
  border: 1px solid rgba(255, 255, 255, 0.16);
}

.sim-grid article {
  min-height: 300px;
  padding: 32px;
  background: rgba(255, 255, 255, 0.08);
}

.sim-grid span {
  color: var(--gold);
  font-weight: 900;
}

.sim-grid h3 {
  margin: 18px 0 14px;
  font-size: 26px;
}

.sim-grid p {
  color: rgba(255, 255, 255, 0.72);
  line-height: 1.8;
}

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

.data-layout {
  display: grid;
  grid-template-columns: minmax(320px, 0.8fr) minmax(0, 1.2fr);
  gap: 54px;
  align-items: start;
}

.data-cards {
  display: grid;
  gap: 14px;
}

.data-cards article {
  padding: 26px;
  background: var(--surface);
  border-left: 4px solid var(--green);
}

.data-cards strong {
  display: block;
  margin-bottom: 10px;
  font-size: 22px;
}

.data-cards span {
  color: var(--muted);
  line-height: 1.75;
}

.next-section {
  display: grid;
  grid-template-columns: 1fr auto;
  gap: 32px;
  align-items: center;
  padding: 70px 8vw;
  color: var(--white);
  background: #0b1014;
}

.next-section h2 {
  margin: 0;
  font-size: clamp(28px, 4vw, 48px);
}

.next-section p {
  color: rgba(255, 255, 255, 0.68);
}

.next-actions {
  display: flex;
  flex-wrap: wrap;
  gap: 12px;
}

.button {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  min-width: 146px;
  height: 48px;
  padding: 0 18px;
  color: var(--white);
  background: var(--green);
  border-radius: 4px;
  font-weight: 800;
}

.button.secondary {
  background: transparent;
  border: 1px solid rgba(255, 255, 255, 0.42);
}

@media (max-width: 980px) {
  .detail-header {
    padding: 0 22px;
  }

  .detail-nav {
    gap: 16px;
  }

  .topic-bar {
    grid-template-columns: repeat(7, minmax(0, 1fr));
  }

  .product-row,
  .sim-grid,
  .data-layout,
  .next-section {
    grid-template-columns: 1fr;
  }

  .product-copy {
    padding: 34px;
  }
}

@media (max-width: 680px) {
  .detail-logo {
    width: 122px;
  }

  .detail-brand {
    min-width: 138px;
  }

  .detail-nav {
    gap: 12px;
    font-size: 13px;
  }

  .detail-nav a:nth-child(2) {
    display: none;
  }

  .drone-hero,
  .section,
  .next-section {
    padding-left: 22px;
    padding-right: 22px;
  }

  .topic-bar {
    padding-left: 22px;
    padding-right: 22px;
    grid-template-columns: repeat(3, minmax(0, 1fr));
  }

  .product-media {
    min-height: 280px;
    padding: 24px;
  }

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