@charset "UTF-8";
/* ==========================================================================
   蓝图娱乐 · 蓝图声学 LANTU ACOUSTICS
   视觉体系：声场蓝图（Graphite / Bone / Copper，工程制图网格 + 直角构件）
   全站前缀 .lt-，零依赖，移动优先
   ========================================================================== */

:root {
  --ink: #14161a;
  --ink-soft: #1c1f24;
  --paper: #f3f2ed;
  --paper-2: #e9e8e1;
  --white: #ffffff;
  --line: #d7d5ca;
  --line-soft: #e2e0d7;
  --copper: #b76a3f;
  --copper-deep: #9a5330;
  --copper-soft: #d08a5d;
  --mute: #6d6c66;
  --ok: #3f7a5c;
  --shell: 1200px;
  --mono: ui-monospace, "SFMono-Regular", Consolas, "Liberation Mono", monospace;
  --sans: "Helvetica Neue", "Segoe UI", "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei", Arial, sans-serif;
}

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

html {
  -webkit-text-size-adjust: 100%;
  scroll-behavior: smooth;
}

body {
  margin: 0;
  font-family: var(--sans);
  font-size: 16px;
  line-height: 1.75;
  color: var(--ink);
  background: var(--paper);
  -webkit-font-smoothing: antialiased;
}

img { display: block; max-width: 100%; height: auto; }
a { color: inherit; text-decoration: none; }
ul, ol { margin: 0; padding: 0; list-style: none; }
h1, h2, h3, h4, p, figure, blockquote { margin: 0; }
button { font: inherit; color: inherit; }
svg { display: block; }
::selection { background: var(--copper); color: #fff; }

.lt-shell {
  width: 100%;
  max-width: var(--shell);
  margin: 0 auto;
  padding: 0 24px;
}

.lt-sr {
  position: absolute;
  width: 1px; height: 1px;
  padding: 0; margin: -1px;
  overflow: hidden;
  clip: rect(0 0 0 0);
  white-space: nowrap;
  border: 0;
}

/* ---------- 通用按钮 / 链接 ---------- */
.lt-btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 10px;
  min-height: 46px;
  padding: 0 22px;
  border: 1px solid transparent;
  border-radius: 0;
  font-size: 14px;
  font-weight: 600;
  letter-spacing: 0.06em;
  cursor: pointer;
  transition: background .25s ease, color .25s ease, border-color .25s ease, transform .25s ease;
}
.lt-btn--copper { background: var(--copper); color: #fff; }
.lt-btn--copper:hover { background: var(--copper-deep); }
.lt-btn--line { border-color: var(--ink); color: var(--ink); background: transparent; }
.lt-btn--line:hover { background: var(--ink); color: var(--paper); }
.lt-btn--ghost { border-color: rgba(243, 242, 237, .35); color: #f3f2ed; background: transparent; }
.lt-btn--ghost:hover { border-color: var(--copper-soft); color: var(--copper-soft); }
.lt-btn--lg { min-height: 54px; padding: 0 32px; font-size: 15px; }
.lt-textlink {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  font-size: 14px;
  font-weight: 600;
  letter-spacing: .04em;
  color: var(--copper);
  border-bottom: 1px solid rgba(183, 106, 63, .4);
  padding-bottom: 2px;
}
.lt-textlink:hover { color: var(--copper-deep); border-color: var(--copper-deep); }
.lt-textlink--light { color: var(--copper-soft); border-color: rgba(208, 138, 93, .45); }

/* ---------- 顶部通告条 ---------- */
.lt-topbar {
  background: #101216;
  color: #b9b7ae;
  border-bottom: 1px solid rgba(243, 242, 237, .08);
  font-size: 12px;
  letter-spacing: .08em;
}
.lt-topbar .lt-shell {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 16px;
  min-height: 36px;
  padding-top: 6px;
  padding-bottom: 6px;
}
.lt-topbar b { color: var(--copper-soft); font-weight: 600; }
.lt-topbar a { color: #dedcd3; }
.lt-topbar a:hover { color: var(--copper-soft); }

/* ---------- 页头 ---------- */
.lt-head {
  position: sticky;
  top: 0;
  z-index: 60;
  background: rgba(243, 242, 237, .94);
  backdrop-filter: blur(10px);
  border-bottom: 1px solid var(--line);
}
.lt-head.is-stuck { box-shadow: 0 10px 30px rgba(20, 22, 26, .07); }
.lt-head .lt-shell {
  display: flex;
  align-items: center;
  gap: 28px;
  min-height: 76px;
}
.lt-brand { flex: 0 0 auto; }
.lt-brand img { width: 214px; height: auto; }
.lt-head nav { flex: 1 1 auto; }
.lt-nav {
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 2px;
}
.lt-nav a {
  position: relative;
  display: inline-block;
  padding: 9px 12px;
  font-size: 14px;
  letter-spacing: .04em;
  color: #33352f;
}
.lt-nav a::after {
  content: "";
  position: absolute;
  left: 12px; right: 12px; bottom: 2px;
  height: 1px;
  background: var(--copper);
  transform: scaleX(0);
  transform-origin: left;
  transition: transform .25s ease;
}
.lt-nav a:hover::after,
.lt-nav a.is-on::after { transform: scaleX(1); }
.lt-nav a.is-on { color: var(--ink); font-weight: 600; }
.lt-head-side {
  display: flex;
  align-items: center;
  gap: 12px;
  flex: 0 0 auto;
}
.lt-head-side .lt-btn { min-height: 40px; padding: 0 18px; }
.lt-login { font-size: 14px; color: var(--mute); }
.lt-login:hover { color: var(--ink); }
.lt-burger {
  display: none;
  width: 42px; height: 42px;
  border: 1px solid var(--line);
  background: transparent;
  cursor: pointer;
  position: relative;
}
.lt-burger span,
.lt-burger span::before,
.lt-burger span::after {
  position: absolute;
  left: 50%; top: 50%;
  width: 18px; height: 1px;
  background: var(--ink);
  content: "";
  transition: transform .25s ease, opacity .25s ease;
}
.lt-burger span { transform: translate(-50%, -50%); }
.lt-burger span::before { left: 0; top: -6px; transform: none; }
.lt-burger span::after { left: 0; top: 6px; transform: none; }
.lt-burger.is-open span { background: transparent; }
.lt-burger.is-open span::before { top: 0; transform: rotate(45deg); }
.lt-burger.is-open span::after { top: 0; transform: rotate(-45deg); }

/* ---------- 首屏 ---------- */
.lt-hero {
  position: relative;
  overflow: hidden;
  background: var(--ink);
  color: #f3f2ed;
}
.lt-hero::before {
  content: "";
  position: absolute;
  inset: 0;
  background-image:
    linear-gradient(rgba(243, 242, 237, .05) 1px, transparent 1px),
    linear-gradient(90deg, rgba(243, 242, 237, .05) 1px, transparent 1px);
  background-size: 58px 58px;
  -webkit-mask-image: radial-gradient(120% 90% at 30% 40%, #000 20%, transparent 78%);
  mask-image: radial-gradient(120% 90% at 30% 40%, #000 20%, transparent 78%);
}
.lt-hero::after {
  content: "";
  position: absolute;
  width: 620px; height: 620px;
  right: -160px; top: -220px;
  border-radius: 50%;
  background: radial-gradient(circle, rgba(183, 106, 63, .28) 0%, rgba(183, 106, 63, 0) 66%);
  pointer-events: none;
}
.lt-hero-inner {
  position: relative;
  z-index: 2;
  display: grid;
  grid-template-columns: 1.04fr .96fr;
  align-items: center;
  gap: 54px;
  padding-top: 64px;
  padding-bottom: 72px;
}
.lt-kicker {
  display: inline-flex;
  align-items: center;
  gap: 12px;
  font-family: var(--mono);
  font-size: 12px;
  letter-spacing: .22em;
  color: var(--copper-soft);
}
.lt-kicker::before {
  content: "";
  width: 34px; height: 1px;
  background: var(--copper);
}
.lt-hero-title {
  margin: 18px 0 22px;
  font-size: clamp(38px, 4.6vw, 62px);
  line-height: 1.1;
  font-weight: 700;
  letter-spacing: -0.01em;
}
.lt-hero-title .lt-outline {
  color: transparent;
  -webkit-text-stroke: 1px rgba(243, 242, 237, .78);
}
.lt-hero-title em {
  font-style: normal;
  color: var(--copper-soft);
}
.lt-hero-lead {
  max-width: 560px;
  font-size: 16px;
  line-height: 1.95;
  color: #bcbab1;
}
.lt-hero-actions {
  display: flex;
  flex-wrap: wrap;
  gap: 14px;
  margin-top: 32px;
}
.lt-hero-trust {
  display: flex;
  flex-wrap: wrap;
  gap: 10px 26px;
  margin-top: 34px;
  padding-top: 22px;
  border-top: 1px solid rgba(243, 242, 237, .14);
  font-family: var(--mono);
  font-size: 11.5px;
  letter-spacing: .1em;
  color: #9e9c93;
}
.lt-hero-trust span::before {
  content: "+";
  color: var(--copper);
  margin-right: 8px;
}
.lt-hero-figure { position: relative; }
.lt-frame {
  position: relative;
  padding: 12px;
  border: 1px solid rgba(243, 242, 237, .16);
}
.lt-frame::before,
.lt-frame::after {
  content: "";
  position: absolute;
  width: 20px; height: 20px;
  border: 1px solid var(--copper);
}
.lt-frame::before { top: -1px; left: -1px; border-right: 0; border-bottom: 0; }
.lt-frame::after { right: -1px; bottom: -1px; border-left: 0; border-top: 0; }
.lt-frame img { width: 100%; aspect-ratio: 4 / 3; object-fit: cover; }
.lt-hero-card {
  position: absolute;
  left: -26px;
  bottom: 26px;
  min-width: 206px;
  padding: 16px 20px;
  background: #101216;
  border-left: 2px solid var(--copper);
  box-shadow: 0 18px 40px rgba(0, 0, 0, .3);
}
.lt-hero-card b {
  display: block;
  font-family: var(--mono);
  font-size: 12px;
  letter-spacing: .18em;
  color: var(--copper-soft);
  font-weight: 500;
}
.lt-hero-card span {
  display: block;
  margin-top: 4px;
  font-size: 15px;
  color: #efeee7;
}
.lt-hero-card small {
  display: block;
  margin-top: 2px;
  font-size: 12px;
  color: #8f8d85;
}

/* 声波装饰 */
.lt-wave-mark {
  position: absolute;
  right: 0; bottom: 0;
  width: 360px;
  opacity: .5;
  pointer-events: none;
}

/* ---------- 跑马灯 ---------- */
.lt-marquee {
  overflow: hidden;
  background: #0f1115;
  border-top: 1px solid rgba(243, 242, 237, .1);
  border-bottom: 1px solid rgba(243, 242, 237, .1);
}
.lt-marquee-track {
  display: flex;
  width: max-content;
  animation: lt-slide 38s linear infinite;
}
.lt-marquee span {
  display: inline-flex;
  align-items: center;
  gap: 22px;
  padding: 12px 22px;
  font-family: var(--mono);
  font-size: 12px;
  letter-spacing: .24em;
  color: #8e8c83;
  white-space: nowrap;
}
.lt-marquee span i {
  font-style: normal;
  color: var(--copper);
}
@keyframes lt-slide {
  from { transform: translateX(0); }
  to { transform: translateX(-50%); }
}

/* ---------- 数据条 ---------- */
.lt-stats { background: var(--paper); border-bottom: 1px solid var(--line); }
.lt-stats-grid {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  padding: 34px 0;
}
.lt-stat {
  padding: 2px 26px;
  border-left: 1px solid var(--line);
}
.lt-stat:first-child { border-left: 0; padding-left: 0; }
.lt-stat b {
  display: block;
  font-family: var(--mono);
  font-size: clamp(24px, 2.6vw, 34px);
  font-weight: 600;
  letter-spacing: -0.02em;
  line-height: 1.2;
}
.lt-stat span {
  display: block;
  margin-top: 6px;
  font-size: 13px;
  color: var(--mute);
  letter-spacing: .04em;
}

/* ---------- 区块骨架 ---------- */
.lt-sec { padding: 96px 0; }
.lt-sec--paper { background: var(--paper-2); }
.lt-sec--dark { background: var(--ink); color: #f3f2ed; }
.lt-sec--tight { padding: 72px 0; }
.lt-sec-head {
  display: grid;
  grid-template-columns: 88px minmax(0, 1fr);
  gap: 22px;
  padding-top: 22px;
  margin-bottom: 46px;
  border-top: 1px solid var(--line);
}
.lt-sec--dark .lt-sec-head { border-color: rgba(243, 242, 237, .16); }
.lt-sec-index {
  font-family: var(--mono);
  font-size: 12px;
  letter-spacing: .18em;
  color: var(--copper);
  padding-top: 6px;
}
.lt-sec-title {
  font-size: clamp(27px, 3vw, 40px);
  line-height: 1.24;
  font-weight: 700;
  letter-spacing: -0.01em;
}
.lt-sec-lead {
  max-width: 760px;
  margin-top: 12px;
  font-size: 15.5px;
  line-height: 1.9;
  color: var(--mute);
}
.lt-sec--dark .lt-sec-lead { color: #b3b1a8; }
.lt-sec-side {
  display: flex;
  align-items: flex-end;
  justify-content: space-between;
  gap: 24px;
}

/* ---------- 产品筛选 ---------- */
.lt-filters {
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
  margin-bottom: 28px;
}
.lt-filters button {
  padding: 8px 16px;
  border: 1px solid var(--line);
  background: transparent;
  font-family: var(--mono);
  font-size: 11.5px;
  letter-spacing: .1em;
  color: var(--mute);
  cursor: pointer;
  transition: background .2s ease, color .2s ease, border-color .2s ease;
}
.lt-filters button:hover { border-color: var(--ink); color: var(--ink); }
.lt-filters button.is-on { background: var(--ink); border-color: var(--ink); color: var(--copper-soft); }

/* ---------- 产品卡片 ---------- */
.lt-pgrid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  border-top: 1px solid var(--line);
  border-left: 1px solid var(--line);
}
.lt-pcard {
  position: relative;
  display: flex;
  flex-direction: column;
  padding: 20px;
  border-right: 1px solid var(--line);
  border-bottom: 1px solid var(--line);
  background: transparent;
  transition: background .3s ease;
}
.lt-pcard:hover { background: rgba(255, 255, 255, .62); }
.lt-pcard-media {
  position: relative;
  display: block;
  overflow: hidden;
  background: var(--paper-2);
}
.lt-pcard-media img {
  width: 100%;
  aspect-ratio: 4 / 5;
  object-fit: cover;
  transition: transform .7s cubic-bezier(.2, .7, .2, 1);
}
.lt-pcard:hover .lt-pcard-media img { transform: scale(1.035); }
.lt-pcard-num {
  position: absolute;
  top: 12px; left: 12px;
  z-index: 2;
  padding: 3px 8px;
  background: var(--ink);
  color: var(--copper-soft);
  font-family: var(--mono);
  font-size: 10.5px;
  letter-spacing: .14em;
}
.lt-pcard-body { padding: 18px 2px 4px; }
.lt-pcard-tag {
  font-family: var(--mono);
  font-size: 10.5px;
  letter-spacing: .18em;
  color: var(--copper);
}
.lt-pcard h3 {
  margin-top: 8px;
  font-size: 19px;
  font-weight: 700;
  line-height: 1.4;
}
.lt-pcard p {
  margin-top: 8px;
  font-size: 13.5px;
  line-height: 1.8;
  color: var(--mute);
}
.lt-pcard-spec {
  display: flex;
  flex-wrap: wrap;
  gap: 6px;
  margin-top: 14px;
}
.lt-pcard-spec span {
  padding: 2px 8px;
  border: 1px solid var(--line);
  font-family: var(--mono);
  font-size: 10.5px;
  letter-spacing: .06em;
  color: #55544e;
}
.lt-pcard-foot {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 12px;
  margin-top: 16px;
  padding-top: 14px;
  border-top: 1px solid var(--line-soft);
  font-family: var(--mono);
  font-size: 11px;
  letter-spacing: .1em;
  color: var(--mute);
}
.lt-pcard-foot i { font-style: normal; color: var(--copper); }

/* ---------- 声学技术 ---------- */
.lt-tech-grid {
  display: grid;
  grid-template-columns: 1fr 1.06fr;
  gap: 64px;
  align-items: center;
}
.lt-tech-figure { position: relative; }
.lt-tech-figure img { width: 100%; aspect-ratio: 3 / 2; object-fit: cover; }
.lt-tech-figure figcaption {
  margin-top: 12px;
  font-family: var(--mono);
  font-size: 11px;
  letter-spacing: .12em;
  color: var(--mute);
}
.lt-tech-list { border-top: 1px solid var(--line); }
.lt-tech-item {
  display: grid;
  grid-template-columns: 52px minmax(0, 1fr);
  gap: 18px;
  padding: 22px 0;
  border-bottom: 1px solid var(--line);
}
.lt-tech-item b {
  font-family: var(--mono);
  font-size: 12px;
  letter-spacing: .12em;
  color: var(--copper);
  font-weight: 500;
  padding-top: 4px;
}
.lt-tech-item h3 { font-size: 17px; font-weight: 700; }
.lt-tech-item p { margin-top: 6px; font-size: 13.5px; line-height: 1.85; color: var(--mute); }

/* ---------- 会员 / 开户 ---------- */
.lt-band {
  position: relative;
  overflow: hidden;
  background: var(--ink);
  color: #f3f2ed;
}
.lt-band::before {
  content: "";
  position: absolute;
  inset: 0;
  background-image:
    linear-gradient(rgba(243, 242, 237, .045) 1px, transparent 1px),
    linear-gradient(90deg, rgba(243, 242, 237, .045) 1px, transparent 1px);
  background-size: 46px 46px;
  -webkit-mask-image: linear-gradient(120deg, #000, transparent 72%);
  mask-image: linear-gradient(120deg, #000, transparent 72%);
}
.lt-band-inner { position: relative; z-index: 2; }
.lt-steps {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  margin-top: 14px;
  border-top: 1px solid rgba(243, 242, 237, .16);
  border-left: 1px solid rgba(243, 242, 237, .16);
}
.lt-step {
  padding: 26px 22px 28px;
  border-right: 1px solid rgba(243, 242, 237, .16);
  border-bottom: 1px solid rgba(243, 242, 237, .16);
}
.lt-step b {
  display: block;
  font-family: var(--mono);
  font-size: 12px;
  letter-spacing: .16em;
  color: var(--copper-soft);
  font-weight: 500;
}
.lt-step h3 { margin-top: 12px; font-size: 17px; font-weight: 700; }
.lt-step p { margin-top: 8px; font-size: 13px; line-height: 1.8; color: #a9a79e; }
.lt-band-actions {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 16px;
  margin-top: 34px;
}
.lt-band-note {
  font-family: var(--mono);
  font-size: 11px;
  letter-spacing: .1em;
  color: #8c8a82;
}

/* ---------- 资讯 ---------- */
.lt-feature {
  display: grid;
  grid-template-columns: 1.1fr 1fr;
  align-items: center;
  gap: 34px;
  padding-bottom: 40px;
  margin-bottom: 8px;
  border-bottom: 1px solid var(--line);
}
.lt-feature img { width: 100%; aspect-ratio: 3 / 2; object-fit: cover; }
.lt-feature h3 {
  margin-top: 10px;
  font-size: clamp(22px, 2.4vw, 30px);
  line-height: 1.45;
  font-weight: 700;
}
.lt-feature p {
  margin-top: 12px;
  font-size: 14px;
  line-height: 1.9;
  color: var(--mute);
}
.lt-news-list { border-top: 1px solid var(--line); margin-top: 6px; }
.lt-nrow {
  display: grid;
  grid-template-columns: 128px minmax(0, 1fr) 44px;
  gap: 26px;
  align-items: center;
  padding: 26px 10px;
  border-bottom: 1px solid var(--line);
  transition: background .25s ease, padding .25s ease;
}
.lt-nrow:hover { background: rgba(255, 255, 255, .6); padding-left: 18px; }
.lt-nrow time {
  font-family: var(--mono);
  font-size: 12px;
  letter-spacing: .08em;
  color: var(--mute);
}
.lt-nrow h3 {
  font-size: 17.5px;
  font-weight: 700;
  line-height: 1.5;
}
.lt-nrow p { margin-top: 5px; font-size: 13.5px; color: var(--mute); }
.lt-nrow .lt-narrow {
  font-size: 18px;
  color: var(--copper);
  text-align: right;
  transition: transform .25s ease;
}
.lt-nrow:hover .lt-narrow { transform: translateX(4px); }

/* ---------- FAQ ---------- */
.lt-faq {
  max-width: 900px;
  border-top: 1px solid var(--line);
}
.lt-faq details { border-bottom: 1px solid var(--line); }
.lt-faq summary {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 20px;
  padding: 20px 4px;
  font-size: 16px;
  font-weight: 600;
  cursor: pointer;
  list-style: none;
}
.lt-faq summary::-webkit-details-marker { display: none; }
.lt-faq summary::after {
  content: "+";
  font-family: var(--mono);
  font-size: 18px;
  color: var(--copper);
  line-height: 1;
  transition: transform .25s ease;
}
.lt-faq details[open] summary::after { transform: rotate(45deg); }
.lt-faq-body {
  padding: 0 4px 22px;
  max-width: 800px;
  font-size: 14px;
  line-height: 1.95;
  color: #514f49;
}

/* ---------- CTA ---------- */
.lt-cta {
  position: relative;
  overflow: hidden;
  background: var(--paper-2);
  border-top: 1px solid var(--line);
  padding: 84px 0;
}
.lt-cta-inner {
  display: grid;
  grid-template-columns: 1.2fr auto;
  gap: 40px;
  align-items: center;
}
.lt-cta h2 {
  font-size: clamp(28px, 3.4vw, 44px);
  line-height: 1.24;
  font-weight: 700;
}
.lt-cta h2 em { font-style: normal; color: var(--copper); }
.lt-cta p { margin-top: 12px; color: var(--mute); font-size: 15px; max-width: 620px; }
.lt-cta-actions { display: flex; flex-wrap: wrap; gap: 14px; }

/* ---------- 关键词内链横条 ---------- */
.lt-keybar {
  background: var(--paper);
  border-top: 1px solid var(--line);
  border-bottom: 1px solid var(--line);
  font-size: 13px;
}
.lt-keybar .lt-shell {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 8px 0;
  padding-top: 16px;
  padding-bottom: 16px;
}
.lt-keybar > .lt-shell > span {
  font-family: var(--mono);
  font-size: 11px;
  letter-spacing: .16em;
  color: var(--mute);
  margin-right: 18px;
}
.lt-keybar a {
  color: #3c3e38;
  padding: 0 14px;
  border-left: 1px solid var(--line);
}
.lt-keybar a:first-of-type { border-left: 0; padding-left: 0; }
.lt-keybar a:hover { color: var(--copper); }

/* ---------- 页脚 ---------- */
.lt-foot {
  background: #101216;
  color: #b6b4ab;
  padding: 66px 0 26px;
  font-size: 13.5px;
}
.lt-foot-grid {
  display: grid;
  grid-template-columns: 1.7fr 1fr 1fr 1.35fr;
  gap: 44px;
  padding-bottom: 40px;
  border-bottom: 1px solid rgba(243, 242, 237, .12);
}
.lt-foot-brand img { width: 210px; height: auto; }
.lt-foot-brand p {
  margin-top: 16px;
  max-width: 320px;
  line-height: 1.9;
  color: #918f87;
  font-size: 13px;
}
.lt-foot-badge {
  display: inline-block;
  margin-top: 16px;
  padding: 3px 10px;
  border: 1px solid rgba(208, 138, 93, .45);
  font-family: var(--mono);
  font-size: 10.5px;
  letter-spacing: .12em;
  color: var(--copper-soft);
}
.lt-foot h4 {
  font-size: 13px;
  font-weight: 600;
  letter-spacing: .12em;
  color: #eeece4;
  margin-bottom: 16px;
}
.lt-foot-links { display: grid; grid-template-columns: 1fr 1fr; gap: 8px 18px; }
.lt-foot-links a:hover { color: var(--copper-soft); }
.lt-foot-contact { display: grid; gap: 8px; }
.lt-foot-contact b { font-weight: 500; color: #8f8d85; }
.lt-foot-contact a:hover { color: var(--copper-soft); }
.lt-foot-keywords {
  margin-top: 28px;
  font-size: 12px;
  line-height: 1.9;
  color: #78766f;
}
.lt-foot-keywords b { color: #a6a49b; font-weight: 500; }
.lt-foot-bottom {
  display: flex;
  flex-wrap: wrap;
  justify-content: space-between;
  gap: 10px;
  margin-top: 22px;
  padding-top: 18px;
  border-top: 1px solid rgba(243, 242, 237, .1);
  font-size: 12px;
  color: #77756e;
}
.lt-foot-bottom a:hover { color: var(--copper-soft); }

/* ---------- 回到顶部 ---------- */
.lt-top {
  position: fixed;
  right: 24px; bottom: 24px;
  z-index: 70;
  width: 46px; height: 46px;
  border: 1px solid var(--copper);
  background: var(--ink);
  color: var(--copper-soft);
  font-size: 16px;
  cursor: pointer;
  opacity: 0;
  visibility: hidden;
  transform: translateY(10px);
  transition: opacity .25s ease, transform .25s ease, visibility .25s;
}
.lt-top.is-show { opacity: 1; visibility: visible; transform: none; }
.lt-top:hover { background: var(--copper); color: #fff; }

/* ---------- 内页页头 ---------- */
.lt-pagehead {
  position: relative;
  overflow: hidden;
  background: var(--ink);
  color: #f3f2ed;
  padding: 58px 0 56px;
}
.lt-pagehead::before {
  content: "";
  position: absolute;
  inset: 0;
  background-image:
    linear-gradient(rgba(243, 242, 237, .045) 1px, transparent 1px),
    linear-gradient(90deg, rgba(243, 242, 237, .045) 1px, transparent 1px);
  background-size: 52px 52px;
  -webkit-mask-image: radial-gradient(100% 100% at 20% 0%, #000, transparent 76%);
  mask-image: radial-gradient(100% 100% at 20% 0%, #000, transparent 76%);
}
.lt-pagehead-inner { position: relative; z-index: 2; }
.lt-crumb {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 10px;
  font-family: var(--mono);
  font-size: 11.5px;
  letter-spacing: .1em;
  color: #8f8d85;
}
.lt-crumb a:hover { color: var(--copper-soft); }
.lt-crumb i { font-style: normal; color: #55564f; }
.lt-crumb b { color: var(--copper-soft); font-weight: 500; }
.lt-pagehead h1 {
  margin-top: 20px;
  font-size: clamp(30px, 3.6vw, 46px);
  line-height: 1.22;
  font-weight: 700;
}
.lt-pagehead .lt-lead {
  max-width: 820px;
  margin-top: 14px;
  font-size: 15px;
  line-height: 1.9;
  color: #b0aea5;
}
.lt-pagehead-meta {
  display: flex;
  flex-wrap: wrap;
  gap: 10px;
  margin-top: 26px;
}
.lt-chip {
  display: inline-flex;
  align-items: center;
  padding: 4px 11px;
  border: 1px solid rgba(243, 242, 237, .22);
  font-family: var(--mono);
  font-size: 10.5px;
  letter-spacing: .12em;
  color: #c9c7be;
}
.lt-chip--copper { border-color: rgba(208, 138, 93, .5); color: var(--copper-soft); }

/* ---------- 内容版式 ---------- */
.lt-split {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 60px;
  align-items: center;
}
.lt-split--figure { grid-template-columns: 1.06fr .94fr; }
.lt-figure { position: relative; }
.lt-figure img { width: 100%; aspect-ratio: 3 / 2; object-fit: cover; }
.lt-figure--portrait img { aspect-ratio: 4 / 5; }
.lt-figure figcaption {
  margin-top: 12px;
  font-family: var(--mono);
  font-size: 11px;
  letter-spacing: .1em;
  color: var(--mute);
}
.lt-copy h2 {
  font-size: clamp(24px, 2.6vw, 33px);
  line-height: 1.3;
  font-weight: 700;
  letter-spacing: -0.01em;
}
.lt-copy h3 {
  margin-top: 30px;
  font-size: 19px;
  font-weight: 700;
}
.lt-copy > h2 + p,
.lt-copy > h3 + p { margin-top: 12px; }
.lt-copy p {
  font-size: 14.5px;
  line-height: 1.95;
  color: #4b4a44;
}
.lt-copy p + p { margin-top: 12px; }
.lt-copy strong { color: var(--ink); }
.lt-lead-copy {
  font-size: 16px !important;
  line-height: 1.95 !important;
  color: var(--ink) !important;
}
.lt-list-check { display: grid; gap: 10px; margin-top: 18px; }
.lt-list-check li {
  position: relative;
  padding-left: 24px;
  font-size: 14px;
  line-height: 1.85;
  color: #4b4a44;
}
.lt-list-check li::before {
  content: "";
  position: absolute;
  left: 0; top: 11px;
  width: 10px; height: 1px;
  background: var(--copper);
}
.lt-tags { display: flex; flex-wrap: wrap; gap: 8px; margin-top: 22px; }
.lt-tags span {
  padding: 3px 10px;
  border: 1px solid var(--line);
  font-family: var(--mono);
  font-size: 10.5px;
  letter-spacing: .08em;
  color: #56554f;
}
.lt-note {
  margin-top: 24px;
  padding: 16px 20px;
  background: var(--paper-2);
  border-left: 2px solid var(--copper);
  font-size: 13.5px;
  line-height: 1.9;
  color: #514f49;
}
.lt-note b { color: var(--ink); }

/* 数据卡片 */
.lt-cards {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 1px;
  background: var(--line);
  border: 1px solid var(--line);
}
.lt-card {
  background: var(--paper);
  padding: 28px 24px;
}
.lt-card b {
  display: block;
  font-family: var(--mono);
  font-size: 12px;
  letter-spacing: .14em;
  color: var(--copper);
  font-weight: 500;
}
.lt-card h3 { margin-top: 10px; font-size: 17px; font-weight: 700; }
.lt-card p { margin-top: 8px; font-size: 13.5px; line-height: 1.85; color: var(--mute); }

/* 规格表 */
.lt-table {
  width: 100%;
  border-collapse: collapse;
  font-size: 13.5px;
}
.lt-table caption {
  caption-side: top;
  text-align: left;
  padding-bottom: 12px;
  font-family: var(--mono);
  font-size: 11px;
  letter-spacing: .12em;
  color: var(--mute);
}
.lt-table th,
.lt-table td {
  padding: 12px 14px;
  border-bottom: 1px solid var(--line);
  text-align: left;
  vertical-align: top;
}
.lt-table th {
  width: 34%;
  font-weight: 600;
  color: var(--ink);
  background: var(--paper-2);
  border-right: 1px solid var(--line);
}
.lt-table td { color: #514f49; }
.lt-table tr:first-child th,
.lt-table tr:first-child td { border-top: 1px solid var(--line); }

/* 时间线 */
.lt-timeline { border-left: 1px solid var(--line); margin-left: 8px; }
.lt-timeline li {
  position: relative;
  padding: 0 0 26px 28px;
}
.lt-timeline li::before {
  content: "";
  position: absolute;
  left: -4px; top: 8px;
  width: 7px; height: 7px;
  background: var(--paper);
  border: 1px solid var(--copper);
  transform: rotate(45deg);
}
.lt-timeline b {
  font-family: var(--mono);
  font-size: 12px;
  letter-spacing: .12em;
  color: var(--copper);
  font-weight: 500;
}
.lt-timeline h3 { margin-top: 4px; font-size: 16px; font-weight: 700; }
.lt-timeline p { margin-top: 4px; font-size: 13.5px; line-height: 1.85; color: var(--mute); }

/* 表单 */
.lt-form {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 18px;
}
.lt-field { display: flex; flex-direction: column; gap: 7px; }
.lt-field--full { grid-column: 1 / -1; }
.lt-field label {
  font-family: var(--mono);
  font-size: 11px;
  letter-spacing: .1em;
  color: var(--mute);
}
.lt-field input,
.lt-field select,
.lt-field textarea {
  width: 100%;
  padding: 12px 14px;
  border: 1px solid var(--line);
  border-radius: 0;
  background: #fbfaf6;
  font-family: inherit;
  font-size: 14px;
  color: var(--ink);
  outline: none;
  transition: border-color .2s ease, background .2s ease;
}
.lt-field textarea { min-height: 128px; resize: vertical; }
.lt-field input:focus,
.lt-field select:focus,
.lt-field textarea:focus {
  border-color: var(--copper);
  background: #fff;
}
.lt-form-actions {
  grid-column: 1 / -1;
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 16px;
  margin-top: 4px;
}
.lt-form-tip {
  display: none;
  grid-column: 1 / -1;
  padding: 12px 16px;
  border-left: 2px solid var(--ok);
  background: #eef3ee;
  font-size: 13px;
  color: #315b44;
}

/* 文章页 */
.lt-article { max-width: 820px; margin: 0 auto; }
.lt-article-meta {
  display: flex;
  flex-wrap: wrap;
  gap: 8px 22px;
  padding-bottom: 22px;
  border-bottom: 1px solid var(--line);
  font-family: var(--mono);
  font-size: 11.5px;
  letter-spacing: .08em;
  color: var(--mute);
}
.lt-article > p {
  margin-top: 20px;
  font-size: 15.5px;
  line-height: 2;
  color: #43423c;
}
.lt-article h2 {
  margin-top: 42px;
  font-size: 24px;
  line-height: 1.35;
  font-weight: 700;
}
.lt-article h3 { margin-top: 28px; font-size: 18px; font-weight: 700; }
.lt-article figure { margin-top: 28px; }
.lt-article figure img { width: 100%; aspect-ratio: 3 / 2; object-fit: cover; }
.lt-article figcaption {
  margin-top: 10px;
  font-family: var(--mono);
  font-size: 11px;
  letter-spacing: .08em;
  color: var(--mute);
}
.lt-article blockquote {
  margin-top: 28px;
  padding: 4px 0 4px 24px;
  border-left: 2px solid var(--copper);
  font-size: 16px;
  line-height: 1.95;
  color: #3c3b35;
}

/* 联系信息块 */
.lt-info {
  display: grid;
  gap: 18px;
}
.lt-info div {
  padding-bottom: 18px;
  border-bottom: 1px solid var(--line);
}
.lt-info b {
  display: block;
  font-family: var(--mono);
  font-size: 11px;
  letter-spacing: .12em;
  color: var(--copper);
  font-weight: 500;
}
.lt-info p { margin-top: 6px; font-size: 14.5px; color: #43423c; }
.lt-info a:hover { color: var(--copper); }

/* 404 */
.lt-404 {
  position: relative;
  overflow: hidden;
  background: var(--ink);
  color: #f3f2ed;
  padding: 110px 0 120px;
  text-align: center;
}
.lt-404::before {
  content: "";
  position: absolute;
  inset: 0;
  background-image:
    linear-gradient(rgba(243, 242, 237, .05) 1px, transparent 1px),
    linear-gradient(90deg, rgba(243, 242, 237, .05) 1px, transparent 1px);
  background-size: 56px 56px;
}
.lt-404-inner { position: relative; z-index: 2; }
.lt-404 b {
  display: block;
  font-family: var(--mono);
  font-size: clamp(72px, 12vw, 132px);
  line-height: 1;
  color: transparent;
  -webkit-text-stroke: 1px rgba(208, 138, 93, .6);
}
.lt-404 h1 { margin-top: 18px; font-size: clamp(24px, 3vw, 34px); }
.lt-404 p { max-width: 560px; margin: 14px auto 0; font-size: 14.5px; line-height: 1.9; color: #a9a79e; }
.lt-404 .lt-404-actions {
  display: flex;
  flex-wrap: wrap;
  justify-content: center;
  gap: 14px;
  margin-top: 30px;
}

/* ---------- 浮现动画 ---------- */
[data-reveal] {
  opacity: 0;
  transform: translateY(18px);
  transition: opacity .7s cubic-bezier(.2, .7, .2, 1), transform .7s cubic-bezier(.2, .7, .2, 1);
}
[data-reveal].is-in { opacity: 1; transform: none; }
@media (prefers-reduced-motion: reduce) {
  html { scroll-behavior: auto; }
  .lt-marquee-track { animation: none; }
  [data-reveal] { opacity: 1; transform: none; transition: none; }
}

/* ==========================================================================
   响应式
   ========================================================================== */
@media (max-width: 1080px) {
  .lt-hero-inner { gap: 38px; }
  .lt-hero-card { left: -8px; min-width: 180px; }
  .lt-head .lt-shell { gap: 18px; }
  .lt-nav a { padding: 9px 9px; font-size: 13.5px; }
  .lt-brand img { width: 190px; }
  .lt-tech-grid { gap: 40px; }
  .lt-foot-grid { grid-template-columns: 1.5fr 1fr 1fr; gap: 32px; }
  .lt-foot-grid > div:last-child { grid-column: 1 / -1; }
  .lt-foot-contact { grid-template-columns: repeat(2, 1fr); }
}

@media (max-width: 900px) {
  .lt-sec { padding: 72px 0; }
  .lt-topbar .lt-shell { font-size: 11px; }
  .lt-hero-inner { grid-template-columns: 1fr; padding-top: 48px; padding-bottom: 56px; }
  .lt-hero-figure { max-width: 620px; }
  .lt-hero-card { left: auto; right: 18px; bottom: 18px; }
  .lt-pgrid { grid-template-columns: repeat(2, 1fr); }
  .lt-tech-grid { grid-template-columns: 1fr; }
  .lt-split,
  .lt-split--figure { grid-template-columns: 1fr; gap: 34px; }
  .lt-split--reverse .lt-figure { order: 2; }
  .lt-steps { grid-template-columns: repeat(2, 1fr); }
  .lt-cta-inner { grid-template-columns: 1fr; gap: 26px; }
  .lt-feature { grid-template-columns: 1fr; gap: 20px; }
  .lt-foot-grid { grid-template-columns: 1fr 1fr; }
  .lt-foot-brand { grid-column: 1 / -1; }
  .lt-cards { grid-template-columns: 1fr; }
  .lt-stats-grid { grid-template-columns: repeat(2, 1fr); gap: 24px 0; }
  .lt-stat:nth-child(3) { border-left: 0; padding-left: 0; }
  .lt-nav {
    display: none;
    position: absolute;
    left: 0; right: 0; top: 100%;
    padding: 10px 24px 18px;
    background: var(--paper);
    border-bottom: 1px solid var(--line);
    box-shadow: 0 24px 40px rgba(20, 22, 26, .1);
    flex-direction: column;
    align-items: stretch;
    gap: 0;
  }
  .lt-head nav { position: static; }
  .lt-nav.is-open { display: flex; }
  .lt-nav a { padding: 12px 4px; border-bottom: 1px solid var(--line-soft); font-size: 15px; }
  .lt-nav a::after { left: 4px; right: auto; width: 24px; bottom: 8px; }
  .lt-head-side .lt-login { display: none; }
  .lt-burger { display: block; }
  .lt-head .lt-shell { justify-content: space-between; }
}

@media (max-width: 640px) {
  .lt-shell { padding: 0 18px; }
  .lt-topbar .lt-shell { justify-content: center; gap: 10px; }
  .lt-topbar .lt-shell > span { overflow: hidden; text-overflow: ellipsis; white-space: nowrap; }
  .lt-topbar .lt-shell > a { display: none; }
  .lt-brand img { width: 164px; }
  .lt-head .lt-shell { min-height: 66px; gap: 10px; }
  .lt-head-side { gap: 8px; }
  .lt-head-side .lt-btn { min-height: 38px; padding: 0 13px; font-size: 12.5px; letter-spacing: .02em; }
  .lt-hero-inner { padding-top: 38px; padding-bottom: 46px; gap: 30px; }
  .lt-hero-title { font-size: clamp(31px, 8.6vw, 40px); margin: 14px 0 16px; }
  .lt-hero-lead { font-size: 14.5px; }
  .lt-hero-actions { margin-top: 26px; }
  .lt-hero-actions .lt-btn { flex: 1 1 auto; padding: 0 18px; }
  .lt-hero-trust { gap: 8px 18px; margin-top: 26px; padding-top: 18px; font-size: 10.5px; }
  .lt-hero-card { right: 8px; bottom: 8px; min-width: 0; padding: 10px 14px; }
  .lt-hero-card span { font-size: 13px; }
  .lt-hero-card small { display: none; }
  .lt-frame { padding: 8px; }
  .lt-stats-grid { grid-template-columns: 1fr; gap: 0; padding: 8px 0 14px; }
  .lt-stat { padding: 16px 0; border-left: 0; border-top: 1px solid var(--line); }
  .lt-stat:first-child { border-top: 0; padding-top: 14px; }
  .lt-sec { padding: 58px 0; }
  .lt-sec--tight { padding: 48px 0; }
  .lt-sec-head { grid-template-columns: 1fr; gap: 8px; padding-top: 18px; margin-bottom: 32px; }
  .lt-sec-index { padding-top: 0; }
  .lt-sec-side { flex-direction: column; align-items: flex-start; gap: 14px; }
  .lt-sec-title { font-size: 26px; }
  .lt-sec-lead { font-size: 14px; }
  .lt-pgrid { grid-template-columns: 1fr; }
  .lt-pcard { padding: 16px; }
  .lt-steps { grid-template-columns: 1fr; }
  .lt-step { padding: 20px 18px 22px; }
  .lt-nrow { grid-template-columns: 1fr 30px; gap: 6px 12px; padding: 20px 4px; }
  .lt-nrow time { grid-column: 1 / -1; }
  .lt-nrow h3 { font-size: 16px; }
  .lt-nrow p { font-size: 13px; }
  .lt-nrow .lt-narrow { grid-column: 2; grid-row: 2; }
  .lt-faq summary { font-size: 15px; padding: 17px 2px; }
  .lt-faq-body { font-size: 13.5px; }
  .lt-cta { padding: 56px 0; }
  .lt-cta h2 { font-size: 27px; }
  .lt-cta-actions .lt-btn { flex: 1 1 auto; }
  .lt-keybar .lt-shell { gap: 6px 0; }
  .lt-keybar a { padding: 0 11px; }
  .lt-foot { padding: 48px 0 22px; }
  .lt-foot-grid { grid-template-columns: 1fr; gap: 26px; padding-bottom: 26px; }
  .lt-foot-brand { grid-column: auto; }
  .lt-foot-contact { grid-template-columns: 1fr; }
  .lt-foot-bottom { flex-direction: column; }
  .lt-top { right: 16px; bottom: 16px; width: 42px; height: 42px; }
  .lt-pagehead { padding: 40px 0 42px; }
  .lt-pagehead h1 { font-size: 28px; margin-top: 16px; }
  .lt-pagehead .lt-lead { font-size: 14px; }
  .lt-pagehead-meta { margin-top: 20px; }
  .lt-form { grid-template-columns: 1fr; gap: 14px; }
  .lt-article > p { font-size: 15px; }
  .lt-article h2 { font-size: 21px; margin-top: 34px; }
  .lt-table th { width: 40%; padding: 10px; }
  .lt-table td { padding: 10px; }
  .lt-marquee span { padding: 10px 16px; font-size: 11px; }
  .lt-hero-figure { max-width: none; }
}