:root {
  --bg: #f6f8fb;
  --ink: #102033;
  --muted: #5c6b7c;
  --line: #dbe3ec;
  --navy: #0b1b2b;
  --blue: #1662d4;
  --green: #17a673;
  --gold: #d79b23;
  --card: #ffffff;
  --shadow: 0 18px 55px rgba(16, 32, 51, 0.12);
}

* {
  box-sizing: border-box;
}

html {
  scroll-behavior: smooth;
}

body {
  margin: 0;
  color: var(--ink);
  background: var(--bg);
  font-family: "Microsoft YaHei", "PingFang SC", "Noto Sans SC", Arial, sans-serif;
  line-height: 1.7;
}

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

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

.site-header {
  position: sticky;
  top: 0;
  z-index: 10;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 24px;
  padding: 16px clamp(20px, 5vw, 72px);
  background: rgba(246, 248, 251, 0.92);
  border-bottom: 1px solid rgba(219, 227, 236, 0.75);
  backdrop-filter: blur(16px);
}

.brand {
  display: inline-flex;
  align-items: center;
  gap: 10px;
  font-weight: 800;
  color: var(--navy);
  white-space: nowrap;
}

.brand-mark {
  display: grid;
  place-items: center;
  width: 36px;
  height: 36px;
  border-radius: 8px;
  color: #fff;
  background: var(--navy);
  font-size: 14px;
  letter-spacing: 0;
}

.nav {
  display: flex;
  gap: clamp(12px, 2vw, 28px);
  color: var(--muted);
  font-size: 15px;
}

.nav a:hover {
  color: var(--blue);
}

.hero {
  display: grid;
  grid-template-columns: minmax(0, 1fr) minmax(320px, 0.95fr);
  align-items: center;
  gap: clamp(32px, 5vw, 72px);
  min-height: calc(100vh - 72px);
  padding: clamp(56px, 8vw, 104px) clamp(20px, 5vw, 72px) 40px;
  background:
    linear-gradient(90deg, rgba(246, 248, 251, 0.98), rgba(246, 248, 251, 0.78)),
    url("assets/security-grid.svg") center / cover no-repeat;
}

.hero-copy {
  max-width: 760px;
}

.eyebrow {
  margin: 0 0 12px;
  color: var(--green);
  font-size: 14px;
  font-weight: 800;
  letter-spacing: 0;
}

h1,
h2,
h3,
p {
  margin-top: 0;
}

h1 {
  margin-bottom: 22px;
  color: var(--navy);
  font-size: clamp(38px, 6vw, 68px);
  line-height: 1.08;
  letter-spacing: 0;
}

h2 {
  margin-bottom: 16px;
  color: var(--navy);
  font-size: clamp(28px, 4vw, 44px);
  line-height: 1.2;
  letter-spacing: 0;
}

h3 {
  margin-bottom: 10px;
  font-size: 20px;
  line-height: 1.35;
}

.lead {
  max-width: 680px;
  color: var(--muted);
  font-size: 20px;
}

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

.button {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  min-height: 48px;
  padding: 12px 20px;
  border-radius: 8px;
  font-weight: 800;
  line-height: 1.2;
}

.primary {
  color: #fff;
  background: var(--blue);
  box-shadow: 0 12px 26px rgba(22, 98, 212, 0.24);
}

.secondary {
  color: var(--navy);
  background: #fff;
  border: 1px solid var(--line);
}

.hero-visual {
  margin: 0;
  filter: drop-shadow(0 28px 45px rgba(16, 32, 51, 0.18));
}

.trust-strip {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 1px;
  margin: 0 clamp(20px, 5vw, 72px);
  overflow: hidden;
  border: 1px solid var(--line);
  border-radius: 8px;
  background: var(--line);
  transform: translateY(-20px);
}

.trust-strip div {
  padding: 22px;
  background: #fff;
}

.trust-strip strong,
.trust-strip span {
  display: block;
}

.trust-strip span {
  color: var(--muted);
  font-size: 14px;
}

.section {
  padding: clamp(64px, 9vw, 112px) clamp(20px, 5vw, 72px);
}

.section-heading {
  max-width: 760px;
  margin-bottom: 34px;
}

.section-heading p:not(.eyebrow),
.split p,
.cta p {
  color: var(--muted);
}

.feature-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 20px;
}

.card {
  min-height: 270px;
  padding: 28px;
  border: 1px solid var(--line);
  border-radius: 8px;
  background: var(--card);
  box-shadow: var(--shadow);
}

.icon {
  display: inline-grid;
  place-items: center;
  width: 42px;
  height: 42px;
  margin-bottom: 26px;
  border-radius: 8px;
  color: #fff;
  background: var(--navy);
  font-weight: 800;
}

.card p,
.security-list p,
.steps span,
.faq p {
  color: var(--muted);
}

.content-block {
  background: #fff;
}

.two-column {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: 22px;
}

.two-column article,
.scenario-grid article {
  padding: 26px;
  border: 1px solid var(--line);
  border-radius: 8px;
  background: #fff;
}

.comparison {
  background: #eef4f8;
}

.table-wrap {
  overflow-x: auto;
  border: 1px solid var(--line);
  border-radius: 8px;
  background: #fff;
  box-shadow: var(--shadow);
}

table {
  width: 100%;
  min-width: 720px;
  border-collapse: collapse;
}

th,
td {
  padding: 18px 20px;
  text-align: left;
  border-bottom: 1px solid var(--line);
  vertical-align: top;
}

th {
  color: #fff;
  background: var(--navy);
  font-weight: 800;
}

tr:last-child td {
  border-bottom: 0;
}

td:first-child {
  color: var(--navy);
  font-weight: 800;
}

.scenario-section {
  background: #fff;
}

.scenario-grid {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 18px;
}

.split {
  display: grid;
  grid-template-columns: 0.82fr 1.18fr;
  gap: clamp(28px, 6vw, 86px);
  background: #fff;
}

.steps {
  display: grid;
  gap: 16px;
  margin: 0;
  padding: 0;
  list-style: none;
  counter-reset: step;
}

.steps li {
  position: relative;
  padding: 22px 22px 22px 72px;
  border: 1px solid var(--line);
  border-radius: 8px;
  background: #f9fbfd;
}

.steps li::before {
  position: absolute;
  top: 22px;
  left: 22px;
  display: grid;
  place-items: center;
  width: 34px;
  height: 34px;
  border-radius: 8px;
  color: #fff;
  background: var(--green);
  font-weight: 800;
  counter-increment: step;
  content: counter(step);
}

.steps strong,
.steps span {
  display: block;
}

.checklist {
  background: #f9fbfd;
}

.check-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 14px;
}

.check-grid div {
  display: flex;
  gap: 12px;
  min-height: 88px;
  padding: 20px;
  border: 1px solid var(--line);
  border-radius: 8px;
  background: #fff;
  color: var(--muted);
  font-weight: 700;
}

.check-grid span {
  display: grid;
  flex: 0 0 auto;
  place-items: center;
  width: 26px;
  height: 26px;
  border-radius: 8px;
  color: #fff;
  background: var(--green);
  font-size: 14px;
  font-weight: 900;
}

.security {
  background: var(--navy);
  color: #fff;
}

.security h2,
.security h3 {
  color: #fff;
}

.security-list {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 22px;
}

.security-list article {
  padding-top: 24px;
  border-top: 2px solid var(--gold);
}

.security-list p {
  color: rgba(255, 255, 255, 0.72);
}

.keyword-section {
  display: grid;
  grid-template-columns: minmax(240px, 0.75fr) minmax(0, 1.25fr);
  gap: 36px;
  align-items: start;
}

.glossary {
  background: #fff;
}

.glossary dl {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 18px;
  margin: 0;
}

.glossary div {
  padding: 24px;
  border-left: 3px solid var(--green);
  background: #f6f8fb;
}

.glossary dt {
  margin-bottom: 8px;
  color: var(--navy);
  font-size: 20px;
  font-weight: 800;
}

.glossary dd {
  margin: 0;
  color: var(--muted);
}

.keyword-cloud {
  display: flex;
  flex-wrap: wrap;
  gap: 12px;
}

.keyword-cloud span {
  padding: 10px 14px;
  border: 1px solid var(--line);
  border-radius: 8px;
  background: #fff;
  color: var(--muted);
  font-weight: 700;
}

.faq {
  background: #fff;
}

details {
  border-top: 1px solid var(--line);
  padding: 22px 0;
}

details:last-child {
  border-bottom: 1px solid var(--line);
}

summary {
  cursor: pointer;
  color: var(--navy);
  font-size: 20px;
  font-weight: 800;
}

.cta {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 28px;
  margin: clamp(40px, 6vw, 72px);
  padding: clamp(28px, 5vw, 48px);
  border-radius: 8px;
  color: #fff;
  background: linear-gradient(135deg, var(--navy), #173b31);
}

.cta h2,
.cta p {
  color: #fff;
}

.cta div {
  max-width: 760px;
}

.footer {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 20px;
  padding: 28px clamp(20px, 5vw, 72px);
  color: var(--muted);
  border-top: 1px solid var(--line);
}

.footer p {
  margin: 0;
}

@media (max-width: 900px) {
  .site-header {
    align-items: flex-start;
    flex-direction: column;
  }

  .nav {
    width: 100%;
    overflow-x: auto;
    padding-bottom: 2px;
  }

  .hero,
  .split,
  .keyword-section {
    grid-template-columns: 1fr;
  }

  .hero {
    min-height: auto;
    padding-top: 44px;
  }

  .hero-visual {
    max-width: 560px;
  }

  .feature-grid,
  .security-list,
  .trust-strip,
  .two-column,
  .scenario-grid,
  .check-grid,
  .glossary dl {
    grid-template-columns: 1fr;
  }

  .trust-strip {
    transform: none;
    margin-top: 20px;
  }

  .cta,
  .footer {
    align-items: flex-start;
    flex-direction: column;
  }
}

@media (max-width: 520px) {
  h1 {
    font-size: 34px;
  }

  .lead {
    font-size: 18px;
  }

  .button {
    width: 100%;
  }

  .steps li {
    padding: 68px 18px 18px;
  }

  .steps li::before {
    top: 18px;
    left: 18px;
  }
}