/* ============== Reset & tokens ============== */
*, *::before, *::after { box-sizing: border-box; }
html { scroll-behavior: smooth; }
body {
  margin: 0;
  font-family: -apple-system, BlinkMacSystemFont, "PingFang SC", "Hiragino Sans GB",
    "Microsoft YaHei", "Segoe UI", Roboto, Helvetica, Arial, sans-serif;
  background: var(--bg-deep);
  color: var(--text-primary);
  line-height: 1.6;
  -webkit-font-smoothing: antialiased;
}

:root {
  --bg-deep: #0A0E1A;
  --bg-elev: #131A2C;
  --bg-elev-2: #1A2238;
  --text-primary: #E8ECF4;
  --text-muted: #8B95A8;
  --accent-gold: #F5C842;
  --accent-blue: #6B9FFF;
  --border: #1F2A44;
  --radius: 14px;
  --shadow-lg: 0 30px 60px -20px rgba(0,0,0,0.5);
}

img { max-width: 100%; display: block; }
a { color: inherit; text-decoration: none; }
button { font: inherit; cursor: pointer; }
h1, h2, h3 { line-height: 1.2; margin: 0 0 0.5em; letter-spacing: -0.01em; }
h1 { font-size: clamp(2rem, 5vw, 3.4rem); }
h2 { font-size: clamp(1.6rem, 3.5vw, 2.4rem); }
h3 { font-size: 1.2rem; }
p { margin: 0 0 1em; color: var(--text-muted); }

.container {
  width: 100%;
  max-width: 1180px;
  margin: 0 auto;
  padding: 0 24px;
}

.eyebrow {
  display: inline-block;
  margin: 0 0 12px;
  padding: 4px 14px;
  font-size: 0.78rem;
  font-weight: 600;
  letter-spacing: 0.12em;
  text-transform: uppercase;
  color: var(--accent-gold);
  background: rgba(245, 200, 66, 0.08);
  border: 1px solid rgba(245, 200, 66, 0.25);
  border-radius: 999px;
}

/* ============== Nav ============== */
.nav {
  position: sticky;
  top: 0;
  z-index: 50;
  background: rgba(10, 14, 26, 0.85);
  backdrop-filter: saturate(160%) blur(10px);
  border-bottom: 1px solid var(--border);
}
.nav__inner {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 24px;
  height: 68px;
}
.brand {
  display: inline-flex;
  align-items: center;
  gap: 10px;
  font-weight: 700;
  font-size: 1.05rem;
}
.brand__logo { width: 26px; height: 26px; }
.brand__name { letter-spacing: 0.01em; }

.nav__links {
  display: none;
  gap: 28px;
}
.nav__links a {
  font-size: 0.95rem;
  color: var(--text-muted);
  transition: color 0.15s;
}
.nav__links a:hover { color: var(--text-primary); }

.lang-toggle {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  padding: 8px 14px;
  background: var(--bg-elev);
  border: 1px solid var(--border);
  color: var(--text-primary);
  border-radius: 999px;
  font-size: 0.85rem;
  font-weight: 600;
  transition: border-color 0.15s, background 0.15s;
}
.lang-toggle:hover { border-color: var(--accent-blue); }
.lang-toggle__sep { color: var(--text-muted); }
.lang-toggle[data-lang="zh"] .lang-toggle__zh { color: var(--accent-gold); }
.lang-toggle[data-lang="en"] .lang-toggle__en { color: var(--accent-gold); }
.lang-toggle[data-lang="zh"] .lang-toggle__en,
.lang-toggle[data-lang="en"] .lang-toggle__zh { color: var(--text-muted); }

@media (min-width: 768px) {
  .nav__links { display: inline-flex; }
}

/* ============== Hero ============== */
.hero {
  position: relative;
  overflow: hidden;
  padding: 80px 0 90px;
  background:
    radial-gradient(ellipse at 80% 10%, rgba(107, 159, 255, 0.18), transparent 50%),
    radial-gradient(ellipse at 10% 90%, rgba(245, 200, 66, 0.10), transparent 50%),
    var(--bg-deep);
}
.hero__bg {
  position: absolute;
  inset: 0;
  pointer-events: none;
}
.orbit {
  position: absolute;
  border: 1px solid rgba(107, 159, 255, 0.12);
  border-radius: 50%;
}
.orbit--1 { width: 600px; height: 600px; top: -200px; right: -200px; }
.orbit--2 { width: 900px; height: 900px; top: -350px; right: -350px; border-color: rgba(107, 159, 255, 0.07); }
.orbit--3 { width: 1300px; height: 1300px; top: -550px; right: -550px; border-color: rgba(245, 200, 66, 0.06); }
.star {
  position: absolute;
  width: 3px; height: 3px;
  background: #fff;
  border-radius: 50%;
  opacity: 0.6;
  box-shadow: 0 0 6px #fff;
}
.star--1 { top: 18%; left: 12%; }
.star--2 { top: 35%; left: 22%; opacity: 0.4; }
.star--3 { top: 60%; left: 8%; opacity: 0.8; }
.star--4 { top: 78%; left: 35%; opacity: 0.3; }

.hero__inner {
  position: relative;
  display: grid;
  grid-template-columns: 1fr;
  gap: 50px;
  align-items: center;
}
.hero__title {
  display: flex;
  flex-direction: column;
  gap: 6px;
  margin: 0 0 24px;
  font-weight: 700;
}
.hero__title-accent {
  background: linear-gradient(110deg, var(--accent-gold), #FFE9A5);
  -webkit-background-clip: text;
  background-clip: text;
  color: transparent;
}
.hero__sub {
  font-size: 1.05rem;
  max-width: 540px;
  margin-bottom: 32px;
}
.hero__cta {
  display: flex;
  flex-wrap: wrap;
  gap: 12px;
  margin-bottom: 40px;
}
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  padding: 13px 26px;
  border-radius: 999px;
  font-weight: 600;
  font-size: 0.95rem;
  transition: transform 0.15s, box-shadow 0.15s, background 0.15s;
  border: 1px solid transparent;
}
.btn--primary {
  background: var(--accent-gold);
  color: #0A0E1A;
  box-shadow: 0 10px 30px -10px rgba(245, 200, 66, 0.5);
}
.btn--primary:hover { transform: translateY(-1px); box-shadow: 0 15px 35px -10px rgba(245, 200, 66, 0.6); }
.btn--ghost {
  background: transparent;
  color: var(--text-primary);
  border-color: var(--border);
}
.btn--ghost:hover { background: var(--bg-elev); border-color: var(--accent-blue); }

.hero__stats {
  list-style: none;
  margin: 0;
  padding: 24px 0 0;
  display: flex;
  gap: 32px;
  border-top: 1px solid var(--border);
}
.hero__stats li {
  display: flex;
  flex-direction: column;
}
.hero__stats strong {
  font-size: 1.8rem;
  font-weight: 700;
  color: var(--text-primary);
  letter-spacing: -0.02em;
}
.hero__stats strong small { font-size: 0.9rem; font-weight: 600; color: var(--text-muted); margin-left: 2px; }
.hero__stats span { font-size: 0.85rem; color: var(--text-muted); }

.hero__visual { position: relative; }
.hero__image-wrap {
  position: relative;
  aspect-ratio: 5 / 4;
  border-radius: 20px;
  overflow: hidden;
  background: linear-gradient(135deg, #1a2540, #0a0e1a);
  border: 1px solid var(--border);
  box-shadow: var(--shadow-lg);
}
.hero__image {
  width: 100%; height: 100%;
  object-fit: cover;
}
.hero__svg-fallback {
  width: 100%; height: 100%;
  background: linear-gradient(135deg, #1a2540, #0a0e1a);
}

@media (min-width: 980px) {
  .hero { padding: 110px 0 130px; }
  .hero__inner {
    grid-template-columns: 1.05fr 1fr;
    gap: 80px;
  }
}

/* ============== Sections ============== */
.section { padding: 90px 0; }
.section--alt { background: linear-gradient(180deg, var(--bg-deep), #07101F); }
.section__head {
  max-width: 720px;
  margin: 0 auto 56px;
  text-align: center;
}
.section__sub { font-size: 1.05rem; }

/* ============== Features ============== */
.features {
  display: grid;
  grid-template-columns: 1fr;
  gap: 20px;
}
@media (min-width: 640px)  { .features { grid-template-columns: repeat(2, 1fr); } }
@media (min-width: 1024px) { .features { grid-template-columns: repeat(3, 1fr); gap: 24px; } }

.feature {
  padding: 32px 28px;
  background: var(--bg-elev);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  transition: transform 0.2s, border-color 0.2s, background 0.2s;
}
.feature:hover {
  transform: translateY(-4px);
  border-color: var(--accent-blue);
  background: var(--bg-elev-2);
}
.feature__icon {
  width: 48px; height: 48px;
  display: inline-flex;
  align-items: center;
  justify-content: center;
  margin-bottom: 18px;
  background: rgba(107, 159, 255, 0.12);
  color: var(--accent-blue);
  border-radius: 12px;
}
.feature__icon svg { width: 26px; height: 26px; }
.feature h3 { color: var(--text-primary); margin-bottom: 8px; }
.feature p { margin: 0; font-size: 0.95rem; }

/* ============== Application cards ============== */
.app-card {
  display: grid;
  grid-template-columns: 1fr;
  gap: 0;
  background: var(--bg-elev);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  overflow: hidden;
  margin-bottom: 28px;
}
.app-card:last-child { margin-bottom: 0; }
.app-card__media {
  background: linear-gradient(135deg, #1a2540, #0a0e1a);
  min-height: 240px;
}
.app-card__media img {
  width: 100%; height: 100%;
  object-fit: cover;
}
.app-card__body {
  padding: 32px 28px;
}
.app-card__body h3 {
  font-size: 1.5rem;
  color: var(--text-primary);
  margin-bottom: 12px;
}
.bullets {
  margin: 16px 0 0;
  padding: 0;
  list-style: none;
}
.bullets li {
  position: relative;
  padding: 8px 0 8px 22px;
  color: var(--text-primary);
  font-size: 0.95rem;
  border-top: 1px solid var(--border);
}
.bullets li:first-child { border-top: none; }
.bullets li::before {
  content: "";
  position: absolute;
  left: 0; top: 50%;
  width: 8px; height: 8px;
  background: var(--accent-gold);
  border-radius: 50%;
  transform: translateY(-50%);
  box-shadow: 0 0 12px rgba(245, 200, 66, 0.5);
}

@media (min-width: 880px) {
  .app-card {
    grid-template-columns: 1fr 1.1fr;
  }
  .app-card--reverse .app-card__media { order: 2; }
  .app-card__body { padding: 48px 44px; }
  .app-card__media { min-height: 380px; }
}

/* ============== Specs ============== */
.specs {
  margin: 0;
  display: grid;
  grid-template-columns: 1fr;
  background: var(--bg-elev);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  overflow: hidden;
}
.specs__row {
  display: grid;
  grid-template-columns: 1fr;
  padding: 18px 24px;
  border-bottom: 1px solid var(--border);
  gap: 6px;
}
.specs__row:last-child { border-bottom: none; }
.specs__row dt {
  margin: 0;
  font-size: 0.85rem;
  font-weight: 600;
  color: var(--text-muted);
  letter-spacing: 0.04em;
  text-transform: uppercase;
}
.specs__row dd {
  margin: 0;
  font-size: 1rem;
  color: var(--text-primary);
}
@media (min-width: 720px) {
  .specs { grid-template-columns: repeat(2, 1fr); }
  .specs__row {
    grid-template-columns: 200px 1fr;
    align-items: center;
    border-right: 1px solid var(--border);
    gap: 16px;
  }
  .specs__row:nth-child(2n) { border-right: none; }
  .specs__row:nth-last-child(-n+2) { border-bottom: none; }
}

/* ============== About + Contact ============== */
.about {
  display: grid;
  grid-template-columns: 1fr;
  gap: 40px;
  align-items: start;
}
.about__col h2 { margin-bottom: 20px; }
.contact-card {
  padding: 32px 28px;
  background: var(--bg-elev);
  border: 1px solid var(--border);
  border-radius: var(--radius);
}
.contact-card h3 {
  color: var(--text-primary);
  font-size: 1.3rem;
  margin-bottom: 20px;
}
.contact-list {
  list-style: none;
  margin: 0;
  padding: 0;
}
.contact-list li {
  display: flex;
  justify-content: space-between;
  align-items: center;
  gap: 16px;
  padding: 14px 0;
  border-top: 1px solid var(--border);
  font-size: 0.95rem;
}
.contact-list li:first-child { border-top: none; padding-top: 0; }
.contact-list__label {
  color: var(--text-muted);
  font-size: 0.85rem;
}
.contact-list a {
  color: var(--accent-blue);
  transition: color 0.15s;
}
.contact-list a:hover { color: var(--accent-gold); }

@media (min-width: 880px) {
  .about { grid-template-columns: 1.1fr 0.9fr; gap: 64px; }
}

/* ============== Footer ============== */
.footer {
  padding: 36px 0;
  border-top: 1px solid var(--border);
  background: #07101F;
}
.footer__inner {
  display: flex;
  flex-direction: column;
  gap: 8px;
  align-items: center;
  justify-content: space-between;
  text-align: center;
  font-size: 0.88rem;
  color: var(--text-muted);
}
.footer__motto { color: var(--accent-gold); opacity: 0.7; font-style: italic; }
@media (min-width: 640px) {
  .footer__inner { flex-direction: row; text-align: left; }
}