* {
  box-sizing: border-box;
}

:root {
  --ink: #071833;
  --ink-2: #0c2748;
  --blue: #1a6dff;
  --blue-soft: #4b8fff;
  --sky: #eaf2ff;
  --paper: #f4f7fc;
  --white: #ffffff;
  --muted: #5b6b82;
  --line: rgba(15, 40, 72, 0.1);
  --shadow: 0 24px 64px rgba(7, 24, 51, 0.12);
  --radius: 22px;
}

html {
  scroll-behavior: smooth;
}

body {
  margin: 0;
  color: var(--ink);
  background: var(--paper);
  font-family: "Segoe UI", "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei", sans-serif;
  line-height: 1.6;
  overflow-x: hidden;
}

h1, h2, h3, .brand-text strong, .hero-brand-name {
  font-family: "Source Han Serif SC", "Noto Serif SC", "Songti SC", "STSong", "SimSun", serif;
  font-weight: 700;
  letter-spacing: 0.01em;
}

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

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

.container {
  width: min(1120px, calc(100% - 40px));
  margin: 0 auto;
}

.page-ambient {
  position: fixed;
  inset: 0;
  pointer-events: none;
  z-index: -1;
  background:
    radial-gradient(ellipse 60% 40% at 10% 0%, rgba(26, 109, 255, 0.08), transparent 55%),
    radial-gradient(ellipse 50% 35% at 90% 20%, rgba(26, 109, 255, 0.05), transparent 50%);
}

/* ---------- Header ---------- */
.site-header {
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  z-index: 50;
  backdrop-filter: blur(18px);
  background: rgba(7, 24, 51, 0.82);
  border-bottom: 1px solid rgba(255, 255, 255, 0.08);
}

.nav-wrap {
  position: relative;
  height: 72px;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 24px;
}

.brand {
  display: inline-flex;
  align-items: center;
  gap: 10px;
  color: var(--white);
  white-space: nowrap;
  font-size: 17px;
  font-weight: 700;
  letter-spacing: 0.06em;
}

.brand img {
  width: 34px;
  height: 34px;
  border-radius: 50%;
  box-shadow: 0 0 0 1.5px rgba(255, 255, 255, 0.2);
}

.nav-links {
  display: flex;
  align-items: center;
  gap: 28px;
  color: rgba(255, 255, 255, 0.72);
  font-size: 14px;
}

.nav-links a {
  position: relative;
  padding: 8px 0;
  transition: color 0.25s ease;
}

.nav-links a::after {
  content: "";
  position: absolute;
  left: 0;
  right: 100%;
  bottom: 0;
  height: 2px;
  border-radius: 99px;
  background: var(--blue-soft);
  transition: right 0.25s ease;
}

.nav-links a:hover,
.nav-links a.is-active {
  color: #fff;
}

.nav-links a:hover::after,
.nav-links a.is-active::after {
  right: 0;
}

.menu-toggle,
.menu-button {
  display: none;
}

.menu-button {
  width: 42px;
  height: 42px;
  align-items: center;
  justify-content: center;
  flex-direction: column;
  gap: 6px;
  border: 1px solid rgba(255, 255, 255, 0.16);
  border-radius: 12px;
  cursor: pointer;
}

.menu-button span {
  width: 18px;
  height: 2px;
  border-radius: 99px;
  background: #fff;
  transition: transform 0.25s ease, opacity 0.25s ease;
}

.nav-cta {
  padding: 10px 18px;
  color: #fff;
  background: var(--blue);
  border-radius: 999px;
  font-size: 14px;
  font-weight: 700;
  box-shadow: 0 10px 28px rgba(26, 109, 255, 0.35);
  transition: transform 0.25s ease, box-shadow 0.25s ease;
}

.nav-cta:hover {
  transform: translateY(-1px);
  box-shadow: 0 14px 36px rgba(26, 109, 255, 0.45);
}

/* ---------- Hero ---------- */
.hero {
  position: relative;
  min-height: 100vh;
  min-height: 100dvh;
  padding: 120px 0 88px;
  color: var(--white);
  background: linear-gradient(160deg, #040e1f 0%, #0a2144 48%, #071833 100%);
  overflow: hidden;
  display: flex;
  align-items: center;
}

.hero-bg {
  position: absolute;
  inset: 0;
  pointer-events: none;
}

.hero-orb {
  position: absolute;
  border-radius: 50%;
  filter: blur(2px);
  animation: orbDrift 14s ease-in-out infinite;
}

.hero-orb-a {
  width: 520px;
  height: 520px;
  left: -120px;
  top: -80px;
  background: radial-gradient(circle, rgba(26, 109, 255, 0.35), transparent 68%);
}

.hero-orb-b {
  width: 420px;
  height: 420px;
  right: -80px;
  bottom: -40px;
  background: radial-gradient(circle, rgba(75, 143, 255, 0.22), transparent 70%);
  animation-delay: -5s;
}

.hero-grid-lines {
  position: absolute;
  inset: 0;
  opacity: 0.18;
  background-image:
    linear-gradient(rgba(255, 255, 255, 0.05) 1px, transparent 1px),
    linear-gradient(90deg, rgba(255, 255, 255, 0.05) 1px, transparent 1px);
  background-size: 56px 56px;
  mask-image: radial-gradient(ellipse 70% 60% at 50% 40%, #000 20%, transparent 75%);
}

.hero-stage {
  position: relative;
  z-index: 2;
  display: grid;
  grid-template-columns: 0.85fr 1.15fr;
  gap: 48px;
  align-items: center;
}

.hero-brand-block {
  text-align: center;
}

.hero-seal {
  width: min(188px, 42vw);
  height: auto;
  margin: 0 auto 22px;
  border-radius: 50%;
  box-shadow:
    0 0 0 10px rgba(255, 255, 255, 0.06),
    0 28px 80px rgba(0, 0, 0, 0.45);
  animation: sealGlow 6s ease-in-out infinite;
}

.hero-brand-name {
  margin: 0 0 8px;
  font-size: clamp(28px, 3.2vw, 40px);
  letter-spacing: 0.08em;
}

.hero-tagline {
  margin: 0;
  color: rgba(255, 255, 255, 0.58);
  font-size: 14px;
  letter-spacing: 0.22em;
}

.hero-copy h1 {
  margin: 0 0 20px;
  font-size: clamp(34px, 4.2vw, 54px);
  line-height: 1.18;
  letter-spacing: 0.02em;
}

.hero-desc {
  margin: 0;
  max-width: 34em;
  color: rgba(255, 255, 255, 0.72);
  font-size: 17px;
  line-height: 1.85;
}

.hero-actions {
  display: flex;
  flex-wrap: wrap;
  gap: 14px;
  margin-top: 32px;
}

.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  min-height: 50px;
  padding: 0 26px;
  border-radius: 999px;
  font-size: 15px;
  font-weight: 700;
  transition: transform 0.25s ease, box-shadow 0.25s ease, background 0.25s ease;
}

.btn:hover {
  transform: translateY(-2px);
}

.btn-primary {
  color: #fff;
  background: linear-gradient(135deg, var(--blue-soft), var(--blue));
  box-shadow: 0 16px 40px rgba(26, 109, 255, 0.4);
}

.btn-ghost {
  color: #fff;
  border: 1px solid rgba(255, 255, 255, 0.22);
  background: rgba(255, 255, 255, 0.06);
}

/* ---------- Trust ---------- */
.trust-strip {
  position: relative;
  z-index: 4;
  margin-top: -36px;
}

.trust-rail {
  display: flex;
  flex-wrap: wrap;
  justify-content: center;
  gap: 10px 28px;
  padding: 22px 28px;
  border-radius: 18px;
  background: rgba(255, 255, 255, 0.96);
  box-shadow: var(--shadow);
  border: 1px solid var(--line);
}

.trust-rail span {
  color: #2a3d5c;
  font-size: 14px;
  font-weight: 700;
  position: relative;
}

.trust-rail span:not(:last-child)::after {
  content: "";
  position: absolute;
  right: -16px;
  top: 50%;
  width: 4px;
  height: 4px;
  border-radius: 50%;
  background: var(--blue);
  opacity: 0.35;
  transform: translateY(-50%);
}

/* ---------- Sections ---------- */
.section {
  padding: 100px 0;
  scroll-margin-top: 88px;
}

.section-heading {
  max-width: 640px;
}

.section-heading.centered {
  max-width: 720px;
  margin: 0 auto 52px;
  text-align: center;
}

.section-kicker {
  display: inline-block;
  color: var(--blue);
  font-size: 13px;
  font-weight: 800;
  letter-spacing: 0.18em;
}

.section-heading h2 {
  margin: 14px 0 14px;
  font-size: clamp(28px, 3.6vw, 44px);
  line-height: 1.22;
  color: var(--ink);
}

.section-heading p {
  margin: 0;
  color: var(--muted);
  font-size: 16px;
  line-height: 1.85;
}

.section-heading.light h2 {
  color: #fff;
}

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

.section-heading.light .section-kicker {
  color: var(--blue-soft);
}

/* ---------- Products ---------- */
.products-section {
  background: linear-gradient(180deg, var(--paper), #eef3fb);
}

.product-grid {
  display: grid;
  grid-template-columns: repeat(3, minmax(0, 1fr));
  gap: 18px;
}

.product-tile {
  padding: 28px 26px;
  border-radius: var(--radius);
  background: rgba(255, 255, 255, 0.9);
  border: 1px solid transparent;
  border-bottom: 3px solid transparent;
  transition: transform 0.25s ease, border-color 0.25s ease, box-shadow 0.25s ease;
}

.product-tile:hover {
  transform: translateY(-4px);
  border-color: rgba(26, 109, 255, 0.12);
  border-bottom-color: var(--blue);
  box-shadow: 0 20px 48px rgba(7, 24, 51, 0.08);
}

.tile-index {
  display: block;
  margin-bottom: 18px;
  color: rgba(26, 109, 255, 0.35);
  font-size: 28px;
  font-weight: 800;
  letter-spacing: -0.04em;
  font-family: "Segoe UI", sans-serif;
}

.product-tile h3 {
  margin: 0 0 12px;
  font-size: 22px;
}

.product-tile p {
  margin: 0;
  color: var(--muted);
  line-height: 1.8;
  font-size: 15px;
}

/* ---------- Flow ---------- */
.solutions-section {
  background: #fff;
}

.flow-track {
  list-style: none;
  margin: 0;
  padding: 0;
  display: grid;
  grid-template-columns: repeat(4, minmax(0, 1fr));
  gap: 16px;
  counter-reset: step;
}

.flow-track li {
  position: relative;
  padding: 28px 22px 26px;
  border-radius: var(--radius);
  background: var(--sky);
  counter-increment: step;
}

.flow-track li::before {
  content: counter(step, decimal-leading-zero);
  display: block;
  margin-bottom: 20px;
  color: var(--blue);
  font-size: 13px;
  font-weight: 800;
  letter-spacing: 0.12em;
  font-family: "Segoe UI", sans-serif;
}

.flow-track strong {
  display: block;
  margin-bottom: 10px;
  font-size: 18px;
  color: var(--ink);
  font-family: "Source Han Serif SC", "Noto Serif SC", "Songti SC", serif;
}

.flow-track span {
  color: var(--muted);
  font-size: 14px;
  line-height: 1.7;
}

/* ---------- Advantages ---------- */
.advantages-section {
  color: #fff;
  background:
    radial-gradient(ellipse 50% 60% at 0% 50%, rgba(26, 109, 255, 0.28), transparent 55%),
    linear-gradient(135deg, #061428, #0c2748);
}

.advantage-row {
  display: grid;
  grid-template-columns: repeat(4, minmax(0, 1fr));
  gap: 16px;
}

.advantage-row article {
  padding: 28px 24px;
  border-radius: var(--radius);
  background: rgba(255, 255, 255, 0.06);
  border: 1px solid rgba(255, 255, 255, 0.1);
}

.advantage-row h3 {
  margin: 0 0 12px;
  font-size: 20px;
}

.advantage-row p {
  margin: 0;
  color: rgba(255, 255, 255, 0.66);
  font-size: 14px;
  line-height: 1.75;
}

/* ---------- Scenarios ---------- */
.scenarios-section {
  background: #fff;
}

.scenario-grid {
  display: grid;
  grid-template-columns: repeat(4, minmax(0, 1fr));
  gap: 16px;
}

.scenario-grid article {
  padding: 28px 24px;
  border-radius: var(--radius);
  background: linear-gradient(180deg, #f8faff, #fff);
  border-left: 3px solid var(--blue);
}

.scenario-grid h3 {
  margin: 0 0 12px;
  font-size: 20px;
}

.scenario-grid p {
  margin: 0;
  color: var(--muted);
  font-size: 14px;
  line-height: 1.75;
}

/* ---------- Security ---------- */
.security-section {
  background: var(--paper);
}

.security-panel {
  display: grid;
  grid-template-columns: 0.85fr 1.15fr;
  gap: 40px;
  align-items: center;
  padding: 44px;
  border-radius: 28px;
  background: #fff;
  border: 1px solid var(--line);
  box-shadow: var(--shadow);
}

.security-list {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 14px;
}

.security-list div {
  padding: 22px;
  border-radius: 16px;
  background: var(--sky);
}

.security-list strong {
  display: block;
  margin-bottom: 8px;
  font-size: 16px;
  color: var(--ink);
}

.security-list p {
  margin: 0;
  color: var(--muted);
  font-size: 14px;
  line-height: 1.7;
}

/* ---------- FAQ ---------- */
.faq-section {
  background: #fff;
}

.faq-wrap {
  display: grid;
  grid-template-columns: 0.7fr 1.3fr;
  gap: 40px;
  align-items: start;
}

.faq-list {
  display: grid;
  gap: 12px;
}

.faq-list details {
  border-radius: 16px;
  background: var(--sky);
  border: 1px solid transparent;
  overflow: hidden;
  transition: border-color 0.25s ease;
}

.faq-list details[open] {
  border-color: rgba(26, 109, 255, 0.2);
  background: #fff;
  box-shadow: 0 12px 32px rgba(7, 24, 51, 0.06);
}

.faq-list summary {
  padding: 18px 22px;
  color: var(--ink);
  font-weight: 700;
  cursor: pointer;
  list-style: none;
}

.faq-list summary::-webkit-details-marker {
  display: none;
}

.faq-list p {
  margin: 0;
  padding: 0 22px 20px;
  color: var(--muted);
  line-height: 1.8;
  font-size: 15px;
}

/* ---------- Contact / QR ---------- */
.contact-section {
  padding-bottom: 110px;
  background:
    radial-gradient(ellipse 50% 60% at 80% 30%, rgba(26, 109, 255, 0.2), transparent 55%),
    linear-gradient(145deg, #061428, #0c2748);
  color: #fff;
}

.contact-stage {
  display: grid;
  grid-template-columns: 1.15fr 0.85fr;
  gap: 48px;
  align-items: center;
}

.contact-copy .section-kicker {
  color: var(--blue-soft);
}

.contact-copy h2 {
  margin: 14px 0 16px;
  font-size: clamp(28px, 3.4vw, 42px);
  color: #fff;
}

.contact-copy > p {
  margin: 0;
  max-width: 36em;
  color: rgba(255, 255, 255, 0.7);
  line-height: 1.85;
}

.contact-bullets {
  margin: 28px 0 0;
  padding: 0;
  list-style: none;
  display: grid;
  gap: 10px;
}

.contact-bullets li {
  position: relative;
  padding-left: 18px;
  color: rgba(255, 255, 255, 0.78);
  font-size: 15px;
}

.contact-bullets li::before {
  content: "";
  position: absolute;
  left: 0;
  top: 0.55em;
  width: 7px;
  height: 7px;
  border-radius: 50%;
  background: var(--blue-soft);
}

.qr-panel {
  justify-self: end;
  text-align: center;
}

.qr-frame {
  position: relative;
  width: min(260px, 72vw);
  aspect-ratio: 1;
  margin: 0 auto;
  padding: 18px;
  border-radius: 28px;
  background: #fff;
  box-shadow:
    0 0 0 1px rgba(255, 255, 255, 0.12),
    0 28px 80px rgba(0, 0, 0, 0.35);
  animation: panelLift 7s ease-in-out infinite;
}

.qr-image {
  width: 100%;
  height: 100%;
  object-fit: contain;
  border-radius: 12px;
}

.qr-caption {
  margin: 18px 0 0;
  color: rgba(255, 255, 255, 0.62);
  font-size: 14px;
  letter-spacing: 0.06em;
}

/* ---------- Footer ---------- */
.site-footer {
  color: rgba(255, 255, 255, 0.62);
  background: #030a16;
}

.footer-grid {
  display: grid;
  grid-template-columns: 1.5fr repeat(3, 1fr);
  gap: 36px;
  padding: 56px 0;
}

.footer-brand {
  display: inline-flex;
  align-items: center;
  gap: 12px;
  margin-bottom: 16px;
  color: #fff;
  font-weight: 700;
}

.footer-brand img {
  width: 36px;
  height: 36px;
  border-radius: 50%;
}

.site-footer p {
  margin: 0;
  max-width: 320px;
  line-height: 1.8;
  font-size: 14px;
}

.site-footer h3 {
  margin: 0 0 16px;
  color: #fff;
  font-size: 15px;
  font-family: inherit;
}

.site-footer a {
  display: block;
  margin: 10px 0;
  font-size: 14px;
  transition: color 0.2s ease;
}

.site-footer a:hover {
  color: var(--blue-soft);
}

.footer-bottom {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  justify-content: center;
  gap: 8px 18px;
  padding: 18px 20px;
  text-align: center;
  border-top: 1px solid rgba(255, 255, 255, 0.08);
  color: rgba(255, 255, 255, 0.38);
  font-size: 13px;
}

.footer-bottom a {
  display: inline;
  margin: 0;
  color: rgba(255, 255, 255, 0.46);
}

.footer-bottom a:hover {
  color: var(--blue-soft);
}

.back-to-top {
  position: fixed;
  right: 24px;
  bottom: 24px;
  z-index: 60;
  width: 48px;
  height: 48px;
  display: grid;
  place-items: center;
  border-radius: 50%;
  color: #fff;
  background: var(--blue);
  box-shadow: 0 14px 36px rgba(26, 109, 255, 0.4);
  font-size: 20px;
  font-weight: 800;
  opacity: 0;
  pointer-events: none;
  transform: translateY(12px);
  transition: opacity 0.25s ease, transform 0.25s ease;
}

.back-to-top.is-visible {
  opacity: 1;
  pointer-events: auto;
  transform: translateY(0);
}

@keyframes orbDrift {
  0%, 100% { transform: translate(0, 0) scale(1); }
  50% { transform: translate(24px, 16px) scale(1.06); }
}

@keyframes sealGlow {
  0%, 100% {
    transform: translateY(0);
    box-shadow:
      0 0 0 10px rgba(255, 255, 255, 0.06),
      0 28px 80px rgba(0, 0, 0, 0.45);
  }
  50% {
    transform: translateY(-8px);
    box-shadow:
      0 0 0 14px rgba(26, 109, 255, 0.12),
      0 36px 90px rgba(26, 109, 255, 0.25);
  }
}

@keyframes panelLift {
  0%, 100% { transform: translateY(0); }
  50% { transform: translateY(-10px); }
}

@media (prefers-reduced-motion: reduce) {
  *, *::before, *::after {
    animation-duration: 0.01ms !important;
    animation-iteration-count: 1 !important;
    transition-duration: 0.01ms !important;
    scroll-behavior: auto !important;
  }
}

@media (max-width: 980px) {
  .nav-links {
    position: absolute;
    top: calc(100% + 10px);
    left: 0;
    right: 0;
    display: grid;
    gap: 0;
    padding: 10px;
    border-radius: 16px;
    background: rgba(7, 24, 51, 0.96);
    border: 1px solid rgba(255, 255, 255, 0.1);
    opacity: 0;
    pointer-events: none;
    transform: translateY(-6px);
    transition: opacity 0.25s ease, transform 0.25s ease;
  }

  .nav-links a {
    padding: 12px 14px;
    border-radius: 12px;
  }

  .nav-links a::after {
    display: none;
  }

  .menu-button {
    display: inline-flex;
    order: 3;
  }

  .nav-cta {
    order: 2;
  }

  .menu-toggle:checked ~ .menu-button span:nth-child(1) {
    transform: translateY(8px) rotate(45deg);
  }

  .menu-toggle:checked ~ .menu-button span:nth-child(2) {
    opacity: 0;
  }

  .menu-toggle:checked ~ .menu-button span:nth-child(3) {
    transform: translateY(-8px) rotate(-45deg);
  }

  .menu-toggle:checked ~ .nav-links {
    opacity: 1;
    pointer-events: auto;
    transform: translateY(0);
  }

  .hero-stage,
  .security-panel,
  .faq-wrap,
  .contact-stage {
    grid-template-columns: 1fr;
  }

  .product-grid,
  .flow-track,
  .advantage-row,
  .scenario-grid {
    grid-template-columns: repeat(2, minmax(0, 1fr));
  }

  .hero {
    min-height: auto;
    padding: 110px 0 72px;
  }

  .hero-brand-block {
    order: -1;
  }

  .qr-panel {
    justify-self: center;
  }
}

@media (max-width: 640px) {
  .container {
    width: min(100% - 28px, 1120px);
  }

  .nav-cta {
    display: none;
  }

  .product-grid,
  .flow-track,
  .advantage-row,
  .scenario-grid,
  .security-list,
  .footer-grid {
    grid-template-columns: 1fr;
  }

  .trust-rail span:not(:last-child)::after {
    display: none;
  }

  .section {
    padding: 72px 0;
  }

  .security-panel {
    padding: 28px 22px;
  }

  .hero-actions {
    width: 100%;
  }

  .hero-actions .btn {
    flex: 1 1 auto;
  }
}