:root {
  --blue-900: #0c2d57;
  --blue-700: #0f4c97;
  --blue-600: #1f6feb;
  --blue-500: #38bdf8;
  --blue-100: #eaf4fb;
  --ink: #17233b;
  --muted: #5a6b87;
  --bg: #ffffff;
  --bg-soft: #f5f9fd;
  --radius: 16px;
  --shadow: 0 18px 44px rgba(12, 45, 87, .10);
  --shadow-sm: 0 6px 20px rgba(12, 45, 87, .08);
  --maxw: 1180px;
  --header-h: 68px;
}

* { margin: 0; padding: 0; box-sizing: border-box; }

html { scroll-behavior: smooth; scroll-padding-top: calc(var(--header-h) + 8px); }

body {
  font-family: "PingFang SC", "Microsoft YaHei", "Hiragino Sans GB", -apple-system, "Segoe UI", Roboto, sans-serif;
  color: var(--ink);
  background: var(--bg);
  line-height: 1.7;
  -webkit-font-smoothing: antialiased;
}

img, svg { display: block; max-width: 100%; }
a { color: inherit; text-decoration: none; }
ul { list-style: none; }

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

/* ============ Header ============ */
.site-header {
  position: fixed;
  inset: 0 0 auto 0;
  height: var(--header-h);
  background: rgba(12, 45, 87, 0.02);
  transition: background .3s ease, box-shadow .3s ease;
  z-index: 100;
}

.site-header.scrolled {
  background: rgba(255, 255, 255, 0.96);
  box-shadow: 0 1px 0 rgba(12, 45, 87, .08);
  backdrop-filter: saturate(160%) blur(10px);
}

.header-inner {
  display: flex;
  align-items: center;
  justify-content: space-between;
  height: var(--header-h);
}

.logo {
  display: inline-flex;
  align-items: center;
  gap: 10px;
  color: var(--blue-700);
}

.logo-mark {
  width: 38px; height: 38px;
  display: grid; place-items: center;
  color: #fff;
  background: linear-gradient(135deg, var(--blue-500), var(--blue-600));
  border-radius: 50%;
  box-shadow: 0 6px 14px rgba(31, 111, 235, .35);
}

.logo-mark svg { width: 22px; height: 22px; }

.logo-text {
  font-size: 22px;
  font-weight: 600;
  letter-spacing: 1px;
  color: var(--ink);
}

.logo-text b { color: var(--blue-600); font-weight: 700; }

.site-nav { display: flex; align-items: center; gap: 34px; }

.nav-link {
  position: relative;
  font-size: 16px;
  color: var(--ink);
  padding: 6px 0;
  transition: color .25s ease;
}

.site-header:not(.scrolled) .nav-link { color: rgba(255, 255, 255, .92); }
.site-header:not(.scrolled) .logo-text { color: #fff; }
.site-header:not(.scrolled) .logo-text b { color: var(--blue-500); }

.nav-link::after {
  content: "";
  position: absolute;
  left: 0; bottom: 0;
  width: 0; height: 2px;
  background: var(--blue-500);
  transition: width .25s ease;
}

.nav-link:hover,
.nav-link.active { color: var(--blue-600); }
.site-header:not(.scrolled) .nav-link:hover,
.site-header:not(.scrolled) .nav-link.active { color: var(--blue-500); }

.nav-link:hover::after,
.nav-link.active::after { width: 100%; }

.nav-link.nav-cta {
  padding: 8px 20px;
  border-radius: 999px;
  color: #fff !important;
  background: linear-gradient(135deg, var(--blue-500), var(--blue-600));
  box-shadow: 0 8px 18px rgba(31, 111, 235, .35);
}

.nav-link.nav-cta::after { display: none; }

.nav-toggle {
  display: none;
  flex-direction: column;
  gap: 5px;
  background: none;
  border: 0;
  cursor: pointer;
  padding: 8px;
}

.nav-toggle span {
  width: 24px; height: 2px;
  border-radius: 2px;
  background: var(--ink);
  transition: transform .3s ease, opacity .3s ease;
}

.site-header:not(.scrolled) .nav-toggle span { background: #fff; }

.nav-toggle.open span:nth-child(1) { transform: translateY(7px) rotate(45deg); }
.nav-toggle.open span:nth-child(2) { opacity: 0; }
.nav-toggle.open span:nth-child(3) { transform: translateY(-7px) rotate(-45deg); }

/* ============ Hero ============ */
.hero {
  position: relative;
  min-height: 100vh;
  display: flex;
  align-items: center;
  overflow: hidden;
  color: #fff;
  background:
    radial-gradient(900px 500px at 85% -10%, rgba(56, 189, 248, .55), transparent 60%),
    radial-gradient(700px 480px at 0% 110%, rgba(56, 189, 248, .30), transparent 60%),
    linear-gradient(135deg, #0b3d7d 0%, #123f86 40%, #0c2d57 100%);
}

.hero::before {
  content: "";
  position: absolute;
  width: 640px; height: 640px;
  right: -180px; top: -160px;
  border-radius: 50%;
  border: 2px dashed rgba(255, 255, 255, .18);
  background: radial-gradient(circle, rgba(255,255,255,.08) 0 2px, transparent 3px);
  background-size: 26px 26px;
  animation: hero-spin 60s linear infinite;
}

@keyframes hero-spin { to { transform: rotate(360deg); } }

.hero::after {
  content: "";
  position: absolute;
  width: 300px; height: 300px;
  left: -90px; bottom: -120px;
  border-radius: 42% 58% 55% 45% / 48% 40% 60% 52%;
  background: rgba(56, 189, 248, .18);
  filter: blur(2px);
  animation: blob 9s ease-in-out infinite alternate;
}

@keyframes blob {
  from { border-radius: 42% 58% 55% 45% / 48% 40% 60% 52%; transform: rotate(0deg); }
  to   { border-radius: 55% 45% 42% 58% / 50% 58% 42% 50%; transform: rotate(12deg); }
}

.hero-inner {
  position: relative;
  z-index: 2;
  text-align: center;
  padding: calc(var(--header-h) + 40px) 24px 140px;
}

.hero-tag {
  display: inline-block;
  font-size: 13px;
  letter-spacing: 6px;
  color: #bfe3ff;
  text-transform: uppercase;
  border: 1px solid rgba(255, 255, 255, .35);
  border-radius: 999px;
  padding: 6px 18px;
  margin-bottom: 26px;
  animation: rise .8s ease both;
}

.hero-title {
  font-size: clamp(34px, 6vw, 62px);
  font-weight: 800;
  letter-spacing: 3px;
  line-height: 1.25;
  animation: rise .8s .1s ease both;
}

.hero-title span { color: var(--blue-500); }

.hero-sub {
  margin: 20px auto 36px;
  font-size: clamp(16px, 2.4vw, 20px);
  color: #cfe6fb;
  animation: rise .8s .2s ease both;
}

.hero-actions {
  display: flex;
  gap: 16px;
  justify-content: center;
  flex-wrap: wrap;
  animation: rise .8s .3s ease both;
}

@keyframes rise {
  from { opacity: 0; transform: translateY(26px); }
  to   { opacity: 1; transform: translateY(0); }
}

.btn {
  display: inline-block;
  padding: 13px 30px;
  border-radius: 999px;
  font-size: 16px;
  font-weight: 600;
  transition: transform .25s ease, box-shadow .25s ease, background .25s ease;
}

.btn:hover { transform: translateY(-3px); }

.btn-light {
  color: var(--blue-700);
  background: #fff;
  box-shadow: 0 12px 26px rgba(0, 0, 0, .18);
}

.btn-light:hover { box-shadow: 0 16px 30px rgba(0, 0, 0, .24); }

.btn-ghost {
  color: #fff;
  border: 1.5px solid rgba(255, 255, 255, .65);
}

.btn-ghost:hover { background: rgba(255, 255, 255, .12); }

.hero-wave {
  position: absolute;
  left: 0; right: 0; bottom: -1px;
  height: 130px;
  background: url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' viewBox='0 0 1440 130' preserveAspectRatio='none'%3E%3Cpath fill='%23ffffff' d='M0,64L48,74.7C96,85,192,107,288,106.7C384,107,480,85,576,74.7C672,64,768,64,864,74.7C960,85,1056,107,1152,106.7C1248,107,1344,85,1392,74.7L1440,64L1440,130L0,130Z'/%3E%3C/svg%3E") no-repeat bottom center / cover;
}

.hero-wave-top { top: -1px; bottom: auto; opacity: 0; }

/* ============ Sections ============ */
.section { padding: 90px 0; }

.section-head {
  text-align: center;
  max-width: 680px;
  margin: 0 auto 56px;
}

.section-en {
  font-size: 13px;
  font-weight: 700;
  letter-spacing: 5px;
  text-transform: uppercase;
  color: var(--blue-500);
  margin-bottom: 8px;
}

.section-title {
  font-size: clamp(28px, 4vw, 38px);
  font-weight: 800;
  letter-spacing: 2px;
}

.section-title::after {
  content: "";
  display: block;
  width: 46px; height: 4px;
  border-radius: 4px;
  margin: 14px auto 0;
  background: linear-gradient(90deg, var(--blue-500), var(--blue-600));
}

.section-desc {
  margin-top: 16px;
  color: var(--muted);
}

/* ============ Features ============ */
.features { background: var(--bg-soft); }

.feature-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 26px;
}

.feature-card {
  background: #fff;
  border-radius: var(--radius);
  padding: 34px 28px;
  box-shadow: var(--shadow-sm);
  border: 1px solid #eaf1f9;
  transition: transform .3s ease, box-shadow .3s ease;
}

.feature-card:hover {
  transform: translateY(-8px);
  box-shadow: var(--shadow);
}

.feature-icon {
  width: 66px; height: 66px;
  display: grid; place-items: center;
  color: #fff;
  background: linear-gradient(140deg, var(--blue-500), var(--blue-600));
  border-radius: 20px;
  margin-bottom: 20px;
  box-shadow: 0 10px 20px rgba(31, 111, 235, .28);
}

.feature-icon svg { width: 34px; height: 34px; }

.feature-card h3 { font-size: 20px; margin-bottom: 10px; }
.feature-card p { color: var(--muted); font-size: 15px; }

/* ============ Products ============ */
.products { background: #fff; }

.product-tabs {
  display: flex;
  justify-content: center;
  gap: 12px;
  flex-wrap: wrap;
  margin-bottom: 42px;
}

.product-tab {
  padding: 12px 28px;
  border-radius: 999px;
  border: 1.5px solid #d7e6f5;
  background: #fff;
  color: var(--muted);
  font-size: 16px;
  font-weight: 600;
  cursor: pointer;
  transition: all .25s ease;
}

.product-tab:hover { border-color: var(--blue-500); color: var(--blue-600); }

.product-tab.active {
  color: #fff;
  border-color: transparent;
  background: linear-gradient(135deg, var(--blue-500), var(--blue-600));
  box-shadow: 0 10px 22px rgba(31, 111, 235, .32);
}

.product-panel { display: none; }
.product-panel.active { display: block; animation: rise .4s ease both; }

.product-panel-grid {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 48px;
  align-items: center;
  background: var(--bg-soft);
  border: 1px solid #eaf1f9;
  border-radius: 24px;
  padding: 40px;
}

.product-panel-img {
  background: #fff;
  border-radius: 18px;
  box-shadow: var(--shadow-sm);
  overflow: hidden;
  aspect-ratio: 3 / 2;
}

.product-panel-img img {
  display: block;
  width: 100%;
  height: 100%;
  object-fit: contain;
  object-position: center;
  background: #fff;
}

.product-panel-body h3 {
  font-size: 26px;
  margin-bottom: 14px;
}

.product-panel-body > p { color: var(--muted); margin-bottom: 20px; }

.product-points li {
  position: relative;
  padding: 8px 0 8px 30px;
  color: #33415f;
}

.product-points li::before {
  content: "";
  position: absolute;
  left: 0; top: 15px;
  width: 18px; height: 18px;
  border-radius: 50%;
  background: linear-gradient(140deg, var(--blue-500), var(--blue-600));
  box-shadow: 0 0 0 4px rgba(56, 189, 248, .18);
}

/* ============ About ============ */
.about { background: linear-gradient(180deg, var(--bg-soft), #fff); }

.about-grid {
  display: grid;
  grid-template-columns: 1.15fr .85fr;
  gap: 48px;
  align-items: stretch;
}

.about-text p {
  color: var(--muted);
  margin-bottom: 16px;
  text-align: justify;
}

.about-stats {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 18px;
  margin-top: 30px;
}

.stat {
  text-align: center;
  background: #fff;
  border-radius: var(--radius);
  padding: 22px 12px;
  box-shadow: var(--shadow-sm);
  border: 1px solid #eaf1f9;
}

.stat strong {
  font-size: 32px;
  color: var(--blue-600);
}

.stat span { font-size: 16px; font-weight: 700; color: var(--blue-600); }
.stat p { margin: 4px 0 0; color: var(--muted); font-size: 14px; text-align: center; }

.about-banner {
  position: relative;
  height: 100%;
  min-height: 320px;
  display: flex;
  flex-direction: column;
  justify-content: center;
  color: #fff;
  padding: 40px;
  border-radius: 24px;
  overflow: hidden;
  background:
    radial-gradient(300px 240px at 100% 0%, rgba(56, 189, 248, .6), transparent 60%),
    linear-gradient(150deg, #1450a8, #0b3d7d 70%);
}

.about-banner::before,
.about-banner::after {
  content: "";
  position: absolute;
  border-radius: 50%;
  border: 1.5px dashed rgba(255, 255, 255, .22);
}

.about-banner::before { width: 190px; height: 190px; right: -40px; top: -40px; }
.about-banner::after { width: 130px; height: 130px; left: -30px; bottom: -30px; }

.about-motto-en {
  font-size: 12px;
  letter-spacing: 4px;
  text-transform: uppercase;
  color: #9fd4ff;
  margin-bottom: 14px;
}

.about-banner h3 {
  font-size: 30px;
  line-height: 1.5;
  margin-bottom: 12px;
  position: relative; z-index: 1;
}

.about-banner p { position: relative; z-index: 1; color: #cfe6fb; letter-spacing: 2px; }

.about-values {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 26px;
  margin-top: 56px;
}

.value {
  background: #fff;
  border-radius: var(--radius);
  padding: 28px;
  text-align: center;
  border: 1px solid #eaf1f9;
  box-shadow: var(--shadow-sm);
}

.value h4 {
  position: relative;
  display: inline-block;
  font-size: 20px;
  color: var(--blue-600);
  margin-bottom: 12px;
  padding: 4px 18px;
  border-radius: 999px;
  background: rgba(56, 189, 248, .12);
}

.value p { color: var(--muted); }

/* ============ CTA ============ */
.cta { padding: 0; }

.cta-inner {
  position: relative;
  margin-top: 0;
  text-align: center;
  color: #fff;
  background:
    radial-gradient(500px 260px at 85% 0%, rgba(56, 189, 248, .5), transparent 60%),
    linear-gradient(135deg, #0b3d7d, #123f86);
  border-radius: 26px;
  padding: 70px 40px;
  margin-bottom: 90px;
  overflow: hidden;
}

.cta-inner h2 { font-size: clamp(24px, 3.6vw, 34px); margin-bottom: 12px; }
.cta-inner p { color: #d5e9fb; margin-bottom: 26px; }

/* ============ Footer ============ */
.site-footer { background: #0a2743; color: #b8cfe4; }

.footer-top {
  display: grid;
  grid-template-columns: 1.4fr 0.8fr 1fr 1.2fr;
  gap: 40px;
  padding: 60px 24px 46px;
}

.footer-col h4 {
  color: #fff;
  font-size: 17px;
  margin-bottom: 18px;
  letter-spacing: 1px;
}

.footer-brand .logo { margin-bottom: 16px; }
.footer-brand .logo-text,
.footer-brand .logo-text b { color: #fff; }
.footer-brand p { font-size: 14px; line-height: 1.9; }

.footer-col ul li { padding: 5px 0; font-size: 14px; }

.footer-col ul a { transition: color .2s ease, padding-left .2s ease; }
.footer-col ul a:hover { color: var(--blue-500); padding-left: 6px; }

.footer-contact p { font-size: 14px; padding: 4px 0; }

.footer-bottom {
  border-top: 1px solid rgba(255, 255, 255, .1);
  padding: 18px 0;
}

.footer-bottom-inner {
  display: flex;
  justify-content: space-between;
  align-items: center;
  gap: 12px;
  flex-wrap: wrap;
  font-size: 14px;
}

.footer-bottom a { color: #b8cfe4; transition: color .2s ease; }
.footer-bottom a:hover { color: var(--blue-500); }

/* ============ Back top ============ */
.back-top {
  position: fixed;
  right: 24px; bottom: 24px;
  width: 46px; height: 46px;
  display: grid; place-items: center;
  color: #fff;
  background: linear-gradient(135deg, var(--blue-500), var(--blue-600));
  border: 0;
  border-radius: 50%;
  cursor: pointer;
  opacity: 0;
  visibility: hidden;
  transform: translateY(12px);
  transition: opacity .3s ease, transform .3s ease, visibility .3s;
  box-shadow: 0 10px 22px rgba(31, 111, 235, .38);
  z-index: 90;
}

.back-top.show { opacity: 1; visibility: visible; transform: translateY(0); }

/* ============ Reveal on scroll ============ */
.reveal {
  opacity: 0;
  transform: translateY(30px);
  transition: opacity .7s ease, transform .7s ease;
}

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

/* ============ Responsive ============ */
@media (max-width: 1024px) {
  .feature-grid { grid-template-columns: repeat(2, 1fr); }
  .product-panel-grid { grid-template-columns: 1fr; gap: 30px; }
  .about-grid { grid-template-columns: 1fr; }
  .footer-top { grid-template-columns: repeat(2, 1fr); }
}

@media (max-width: 720px) {
  :root { --header-h: 60px; }
  .section { padding: 66px 0; }

  .site-nav {
    position: fixed;
    top: var(--header-h);
    left: 0; right: 0;
    flex-direction: column;
    align-items: stretch;
    gap: 0;
    background: #fff;
    box-shadow: 0 24px 40px rgba(12, 45, 87, .12);
    padding: 10px 24px 20px;
    transform: translateY(-130%);
    transition: transform .35s ease;
  }

  .site-nav.open { transform: translateY(0); }

  .site-header:not(.scrolled) .site-nav { background: rgba(12, 45, 87, .98); }
  .site-header:not(.scrolled) .nav-link { color: #fff; }

  .nav-link {
    color: var(--ink);
    padding: 14px 0;
    border-bottom: 1px solid #eef4fa;
  }

  .nav-link::after { display: none; }
  .nav-link.active { color: var(--blue-600); }
  .nav-link.nav-cta {
    margin-top: 12px;
    text-align: center;
    border: 0;
  }

  .nav-toggle { display: flex; }

  .feature-grid { grid-template-columns: 1fr; }
  .product-panel-grid { padding: 24px; }
  .about-values { grid-template-columns: 1fr; }
  .product-tab { padding: 10px 18px; font-size: 14px; }
  .cta-inner { padding: 50px 24px; margin-bottom: 60px; }
  .footer-top { grid-template-columns: 1fr; gap: 30px; padding: 44px 24px 30px; }
  .footer-bottom-inner { justify-content: center; text-align: center; }
}