:root { --navy: #07111f; --navy-2: #0c1b2b; --paper: #f5f6f2; --paper-2: #eaede8; --ink: #102131; --body: #53636d; --muted: #778691; --white: #f5fafb; --cyan: #66ddeb; --cyan-deep: #168ca1; --line-light: rgba(16, 33, 49, .14); --line-dark: rgba(231, 246, 248, .16); --site-width: 1440px; --content-width: 1200px; --sans: "HarmonyOS Sans SC", "PingFang SC", "Microsoft YaHei", Arial, sans-serif; --serif: "Songti SC", STSong, "Noto Serif SC", serif; }
* { box-sizing: border-box; }
html { scroll-behavior: smooth; }
body { background: var(--paper); color: var(--ink); font-family: var(--sans); margin: 0; -webkit-font-smoothing: antialiased; }
a { color: inherit; text-decoration: none; } img { display: block; max-width: 100%; } button { font: inherit; }
.site-frame { margin: 0 auto; max-width: var(--site-width); width: calc(100% - 96px); }.content-frame { margin: 0 auto; max-width: var(--content-width); width: calc(100% - 112px); }
#home, #about, #features, #vision { scroll-margin-top: 80px; }

/* Header stays inside the same 1440px website frame. */
.site-header { background: rgba(255, 255, 255, .97); border-bottom: 1px solid rgba(12, 30, 43, .1); height: 80px; position: sticky; top: 0; z-index: 20; }
.header-inner { align-items: center; display: flex; height: 100%; justify-content: space-between; position: relative; }
.brand { align-items: center; color: #102131; display: inline-flex; gap: 9px; height: 52px; }.brand-mark { background: center / contain no-repeat url("./assets/huoyanqiji-logo.png"); display: block; height: 36px; width: 36px; }.brand-mark svg { display: none; }.brand-name { font-size: 23px; font-weight: 700; letter-spacing: .04em; line-height: 1; white-space: nowrap; }
.nav { align-items: stretch; display: flex; height: 100%; position: absolute; right: 0; top: 0; }.nav a { align-items: center; color: #314550; display: flex; font-size: 15px; font-weight: 500; padding: 0 24px; position: relative; transition: color .2s ease; }.nav a::after { background: var(--cyan-deep); bottom: 0; content: ""; height: 2px; left: 24px; opacity: 0; position: absolute; right: 24px; transform: scaleX(.5); transition: opacity .2s ease, transform .2s ease; }.nav a:hover, .nav a.is-current { color: #102131; }.nav a:hover::after, .nav a.is-current::after { opacity: 1; transform: scaleX(1); }.menu-toggle { display: none; }

/* Full-bleed scene, with content and product locked to the theme frame. */
.hero { background: radial-gradient(circle at 73% 62%, #193f61 0%, #0b1c2d 31%, #06111e 65%, #030b16 100%); color: var(--white); overflow: hidden; position: relative; }.hero::before { background: linear-gradient(90deg, rgba(3, 11, 22, .75) 0%, rgba(3, 11, 22, .3) 50%, transparent 78%); content: ""; inset: 0; position: absolute; z-index: 1; }.hero::after { background: linear-gradient(90deg, var(--cyan), transparent 48%); bottom: 0; content: ""; height: 1px; left: 0; opacity: .55; position: absolute; right: 0; z-index: 3; }.hero-light { background: radial-gradient(ellipse, rgba(64, 157, 198, .33), transparent 68%); height: 510px; position: absolute; right: -190px; top: 10%; width: 780px; }.hero-frame { height: clamp(690px, 54vw, 810px); position: relative; }.hero-copy { left: 0; max-width: 600px; position: absolute; top: 50%; transform: translateY(-53%); z-index: 4; }.section-kicker { color: var(--cyan-deep); font-size: 12px; font-weight: 500; letter-spacing: .12em; margin: 0 0 24px; }.section-kicker.light { color: #9aeaf2; }.hero h1 { font-size: clamp(55px, 5.3vw, 80px); font-weight: 500; letter-spacing: -.08em; line-height: 1.1; margin: 0; }.hero h1 em { white-space: nowrap; }.hero h1 em, h2 em { color: #b5f2f8; font-family: var(--serif); font-style: normal; font-weight: 500; letter-spacing: -.1em; }.hero-copy > p:not(.section-kicker) { color: #c7d6db; font-size: 15px; line-height: 2; margin: 31px 0 0; }.button { align-items: center; display: inline-flex; font-size: 13px; gap: 31px; margin-top: 37px; padding: 14px 17px 14px 21px; transition: background .2s ease, color .2s ease; }.button-light { border: 1px solid rgba(209, 239, 242, .62); }.button-light span { color: var(--cyan); font-size: 16px; }.button-light:hover { background: #f3fbfc; color: var(--navy); }.button-light:hover span { color: var(--navy); }.hero-product { filter: drop-shadow(0 22px 22px rgba(0, 4, 11, .38)); pointer-events: none; position: absolute; right: -42px; top: 50%; transform: translateY(-50%); width: min(900px, 65vw); z-index: 2; }.hero-product::after { background: radial-gradient(ellipse, rgba(4, 15, 28, .86), transparent 68%); bottom: -9px; content: ""; filter: blur(8px); height: 46px; left: 13%; position: absolute; width: 76%; z-index: -1; }.hero-product img { height: auto; width: 100%; }

/* Editorial sections use the narrower 1200px reading frame. */
.section-light { background: var(--paper); }
.intro { padding: 122px 0 112px; }
.intro-grid, .vision-grid { display: grid; gap: 72px; grid-template-columns: minmax(0, 1.42fr) minmax(260px, .78fr); }
.intro-title, .vision-title { max-width: 690px; }
h2 { font-size: clamp(43px, 4.5vw, 66px); font-weight: 500; letter-spacing: -.08em; line-height: 1.18; margin: 0; }
.intro-copy, .vision-copy { align-self: end; padding-bottom: 4px; }
.intro-copy p, .vision-copy p { color: var(--body); font-size: 15px; line-height: 2; margin: 0; }
.vision-copy p + p { margin-top: 18px; }
.intro-list { border-top: 1px solid var(--line-light); list-style: none; margin: 30px 0 0; padding: 17px 0 0; }
.intro-list li { color: #40545f; font-size: 13px; line-height: 1.6; margin-top: 11px; padding-left: 16px; position: relative; }
.intro-list li::before { background: var(--cyan-deep); border-radius: 50%; content: ""; height: 5px; left: 0; position: absolute; top: 8px; width: 5px; }

.section-dark { background: var(--navy); color: var(--white); }
.features { overflow: hidden; padding: 132px 0 122px; position: relative; }
.features::before { background: radial-gradient(circle at 83% 38%, rgba(42, 123, 160, .25), transparent 26%); content: ""; inset: 0; pointer-events: none; position: absolute; }
.section-heading { position: relative; }
.section-heading .section-kicker { margin-bottom: 24px; }
.feature-grid { border-top: 1px solid var(--line-dark); display: grid; grid-template-columns: repeat(3, 1fr); margin-top: 76px; position: relative; }
.feature-card { border-bottom: 1px solid var(--line-dark); border-right: 1px solid var(--line-dark); min-height: 244px; padding: 34px 36px 31px; }
.feature-card:nth-child(3n + 1) { padding-left: 0; }
.feature-card:nth-child(3n) { border-right: 0; padding-right: 0; }
.feature-card:nth-child(n + 4) { border-bottom: 0; padding-top: 39px; }
.feature-card h3 { color: #f1f8f9; font-size: 25px; font-weight: 500; letter-spacing: -.05em; margin: 28px 0 14px; }
.feature-card p { color: #c2d0d5; font-size: 14px; line-height: 1.9; margin: 0; max-width: 260px; }
.feature-icon { border: 1px solid rgba(126, 230, 241, .72); border-radius: 50%; display: block; height: 26px; position: relative; width: 26px; }
.icon-key::before { border: 1px solid var(--cyan); border-radius: 50%; content: ""; height: 7px; left: 5px; position: absolute; top: 5px; width: 7px; }
.icon-key::after { background: var(--cyan); content: ""; height: 1px; left: 12px; position: absolute; top: 14px; transform: rotate(45deg); width: 10px; }
.icon-control::after { background: var(--cyan); border-radius: 50%; content: ""; height: 8px; left: 8px; position: absolute; top: 8px; width: 8px; }
.icon-shield { border-radius: 50% 50% 47% 47%; }
.icon-shield::after { border: solid var(--cyan); border-width: 0 1px 1px 0; content: ""; height: 9px; left: 8px; position: absolute; top: 6px; transform: rotate(45deg); width: 5px; }
.icon-location { border-radius: 50% 50% 50% 0; transform: rotate(-45deg); }
.icon-location::after { border: 1px solid var(--cyan); border-radius: 50%; content: ""; height: 7px; left: 8px; position: absolute; top: 8px; width: 7px; }
.icon-route { border-color: #ad9bff; }
.icon-route::after { border-top: 1px solid #ad9bff; content: ""; left: 4px; position: absolute; top: 12px; transform: rotate(-26deg); width: 16px; }
.icon-battery { border-radius: 3px; height: 18px; margin-top: 4px; width: 28px; }
.icon-battery::before { background: var(--cyan); content: ""; height: 8px; left: 4px; position: absolute; top: 4px; width: 15px; }
.icon-battery::after { background: rgba(126, 230, 241, .72); content: ""; height: 7px; position: absolute; right: -4px; top: 4px; width: 3px; }

.use-flow { padding: 118px 0 130px; }
.flow-heading { max-width: 720px; }
.flow-grid { border-top: 1px solid var(--line-light); display: grid; grid-template-columns: repeat(3, 1fr); margin-top: 65px; }
.flow-item { min-height: 155px; padding: 31px 37px 0 0; }
.flow-item + .flow-item { border-left: 1px solid var(--line-light); padding-left: 37px; }
.flow-item span { color: var(--ink); font-size: 22px; font-weight: 600; letter-spacing: -.045em; }
.flow-item p { color: var(--body); font-size: 14px; line-height: 1.9; margin: 16px 0 0; max-width: 265px; }

.principle { background: #0c1a2a; color: var(--white); overflow: hidden; padding: 142px 0 150px; position: relative; }.principle::before { background: radial-gradient(ellipse, rgba(63, 181, 207, .3), transparent 68%); content: ""; height: 420px; left: 43%; position: absolute; top: -280px; width: 760px; }.principle .content-frame { position: relative; }.principle h2 { font-size: clamp(49px, 5.4vw, 78px); }.principle h2 em { color: var(--cyan); }
.vision { padding: 145px 0 150px; }

.footer { background: #07111f; color: #c1d0d5; }.footer-main { align-items: center; display: grid; gap: 30px; grid-template-columns: auto 1fr auto auto; padding: 50px 0; }.brand-inverse { color: #f1f8f9; }.footer-main .brand-mark { height: 40px; width: 40px; }.footer-main .brand-name { font-size: 24px; }.footer-main p { color: #d1dde1; font-size: 15px; margin: 0; }.footer-email { color: #c3d5da; font-size: 13px; transition: color .2s ease; }.footer-email:hover { color: var(--cyan); }.back-to-top { border-bottom: 1px solid rgba(214, 240, 243, .55); color: #eef8f9; font-size: 14px; padding-bottom: 8px; transition: color .2s ease, border-color .2s ease; }.back-to-top span { color: var(--cyan); margin-left: 15px; }.back-to-top:hover { border-color: var(--cyan); color: var(--cyan); }.footer-bottom { border-top: 1px solid rgba(220, 240, 243, .16); color: #b1c1c7; display: flex; flex-wrap: wrap; font-size: 12px; gap: 8px 19px; padding: 19px 0 24px; }.footer-bottom a { color: inherit; transition: color .2s ease; }.footer-bottom a:hover { color: var(--cyan); }.footer-bottom > :not(:first-child)::before { color: #7d929c; content: "·"; margin-right: 19px; }

.reveal { opacity: 0; transform: translateY(18px); transition: opacity .68s ease, transform .68s ease; }.reveal.is-visible { opacity: 1; transform: none; }
@media (max-width: 1100px) { .site-frame { width: calc(100% - 64px); }.content-frame { width: calc(100% - 72px); }.hero-product { right: -90px; width: min(850px, 72vw); }.intro-grid, .vision-grid { gap: 44px; grid-template-columns: minmax(0, 1.25fr) minmax(235px, .85fr); }.feature-card { padding-left: 25px; padding-right: 25px; }.feature-card:nth-child(3n + 1) { padding-left: 0; }.feature-card:nth-child(3n) { padding-right: 0; }.flow-item { padding-right: 25px; }.flow-item + .flow-item { padding-left: 25px; } }
@media (max-width: 760px) { .site-frame, .content-frame { width: calc(100% - 40px); }.site-header { height: 68px; } #home, #about, #features, #vision { scroll-margin-top: 68px; }.brand { gap: 7px; height: 44px; }.brand-mark { height: 33px; width: 33px; }.brand-name { font-size: 20px; }.menu-toggle { align-items: center; background: transparent; border: 0; color: #253947; cursor: pointer; display: flex; gap: 5px; padding: 9px 0 9px 12px; }.menu-toggle span { background: var(--cyan-deep); height: 1px; width: 17px; }.menu-toggle em { font-size: 10px; font-style: normal; letter-spacing: .08em; margin-left: 4px; }.nav { background: #fff; border-bottom: 1px solid rgba(12, 30, 43, .1); display: none; height: auto; left: 0; padding: 8px 20px 18px; right: 0; top: 68px; }.nav.is-open { display: block; }.nav a { border-bottom: 1px solid rgba(12, 30, 43, .09); font-size: 15px; padding: 15px 0; }.nav a::after { display: none; }.nav a:last-child { border-bottom: 0; }
  .hero-frame { height: 700px; }.hero::before { background: linear-gradient(180deg, rgba(3, 11, 22, .2), rgba(3, 11, 22, .77) 52%, rgba(3, 11, 22, .18)); }.hero-light { right: -310px; top: 39%; }.hero-copy { max-width: 100%; top: 72px; transform: none; }.section-kicker { font-size: 11px; margin-bottom: 19px; }.hero h1 { font-size: clamp(47px, 13.4vw, 58px); }.hero-copy > p:not(.section-kicker) { font-size: 13px; line-height: 1.85; margin-top: 25px; }.hero-copy > p br { display: none; }.button { margin-top: 29px; }.hero-product { bottom: -3px; right: -31%; top: auto; transform: none; width: 143%; }.intro, .vision, .use-flow { padding: 88px 0; }.intro-grid, .vision-grid { display: block; }.intro-title, .vision-title { max-width: none; }.intro-copy, .vision-copy { padding-top: 34px; }.intro-copy p, .vision-copy p { font-size: 14px; }.intro-list { margin-top: 25px; }.features { padding: 85px 0 71px; }.section-heading { display: block; }.section-heading .section-kicker { margin-bottom: 24px; }.feature-grid { display: block; margin-top: 51px; }.feature-card, .feature-card:nth-child(n), .feature-card:nth-child(n + 4) { border-bottom: 1px solid var(--line-dark); border-right: 0; min-height: 0; padding: 27px 0; }.feature-card:last-child { border-bottom: 0; }.feature-card h3 { font-size: 23px; margin: 23px 0 11px; }.feature-card p { font-size: 13px; }.flow-grid { display: block; margin-top: 47px; }.flow-item, .flow-item + .flow-item { border-bottom: 1px solid var(--line-light); border-left: 0; min-height: 0; padding: 25px 0; }.flow-item:last-child { border-bottom: 0; }.flow-item span { font-size: 20px; }.flow-item p { font-size: 13px; margin-top: 11px; }.principle { padding: 100px 0 110px; }.principle h2 { font-size: 46px; }.footer-main { align-items: start; display: grid; grid-template-columns: 1fr auto; padding: 40px 0 34px; }.footer-main .brand { height: 44px; }.footer-main .brand-mark { height: 36px; width: 36px; }.footer-main .brand-name { font-size: 21px; }.footer-main p, .footer-email { font-size: 13px; grid-column: 1 / -1; }.footer-email { margin-top: -10px; }.back-to-top { font-size: 12px; grid-column: 2; grid-row: 1; }.footer-bottom { font-size: 11px; padding: 16px 0 20px; } }
@media (prefers-reduced-motion: reduce) { html { scroll-behavior: auto; }.reveal { opacity: 1; transform: none; transition: none; } }
@media (min-width: 761px) and (prefers-reduced-motion: no-preference) { .hero-copy.reveal { transform: translateY(calc(-53% + 18px)); }.hero-copy.reveal.is-visible { transform: translateY(-53%); } }