:root {
  --primary: #3978b7;
  --primary-dark: #285e91;
  --primary-light: #6a9fd0;
  --secondary: #79a9b8;
  --accent: #d5a45f;
  --background: #f4f8fc;
  --surface: #ffffff;
  --surface-muted: #f7fafd;
  --border: #dce7f0;
  --text: #253746;
  --muted: #687c8d;
  --container: min(1120px, calc(100vw - 40px));
  --shadow: 0 20px 54px rgba(40, 94, 145, 0.14);
}

* {
  box-sizing: border-box;
}

html {
  scroll-behavior: smooth;
}

body {
  margin: 0;
  color: var(--text);
  background: var(--background);
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", "PingFang SC",
    "Hiragino Sans GB", "Microsoft YaHei", sans-serif;
  line-height: 1.65;
}

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

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

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

h1 {
  max-width: 680px;
  margin-bottom: 22px;
  font-size: clamp(42px, 6vw, 66px);
  line-height: 1.08;
  letter-spacing: 0;
}

h2 {
  margin-bottom: 14px;
  font-size: clamp(28px, 4vw, 40px);
  line-height: 1.2;
  letter-spacing: 0;
}

h3 {
  margin-bottom: 10px;
  font-size: 21px;
  line-height: 1.3;
}

.site-header {
  position: sticky;
  top: 0;
  z-index: 10;
  background: rgba(244, 248, 252, 0.9);
  border-bottom: 1px solid rgba(220, 231, 240, 0.85);
  backdrop-filter: blur(16px);
}

.header-inner,
.footer-inner {
  width: var(--container);
  margin: 0 auto;
}

.header-inner {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 24px;
  min-height: 68px;
}

.brand,
.nav,
.hero-actions,
.phone-appbar,
.phone-welcome,
.phone-card,
.phone-stats,
.cta,
.footer-inner {
  display: flex;
  align-items: center;
}

.brand {
  gap: 10px;
  font-weight: 850;
}

.brand img,
.cta img {
  border-radius: 18px;
  box-shadow: 0 10px 24px rgba(40, 94, 145, 0.18);
}

.nav {
  gap: 30px;
  color: var(--muted);
  font-size: 15px;
  font-weight: 700;
}

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

.hero {
  width: var(--container);
  margin: 0 auto;
  padding: 82px 0 72px;
  display: grid;
  grid-template-columns: minmax(0, 1fr) minmax(320px, 380px);
  gap: 72px;
  align-items: center;
}

.hero-copy {
  min-width: 0;
}

.eyebrow {
  margin: 0 0 12px;
  color: var(--primary);
  font-size: 14px;
  font-weight: 850;
}

.lead {
  max-width: 620px;
  margin-bottom: 0;
  color: var(--muted);
  font-size: 18px;
}

.hero-actions {
  flex-wrap: wrap;
  gap: 12px;
  margin-top: 30px;
}

.button {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  min-height: 48px;
  padding: 0 22px;
  border: 1px solid var(--border);
  border-radius: 8px;
  font-weight: 850;
}

.button.primary {
  color: #fff;
  background: var(--primary);
  border-color: var(--primary);
  box-shadow: 0 14px 28px rgba(57, 120, 183, 0.22);
}

.button.secondary {
  background: rgba(255, 255, 255, 0.76);
}

.phone-preview {
  width: 100%;
  padding: 18px 18px 22px;
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: 32px;
  box-shadow: var(--shadow);
}

.phone-bar {
  width: 92px;
  height: 5px;
  margin: 2px auto 20px;
  background: #d8e5ef;
  border-radius: 99px;
}

.phone-appbar {
  justify-content: space-between;
  margin-bottom: 18px;
  font-weight: 850;
}

.avatar {
  width: 34px;
  height: 34px;
  background: #e4f0fa;
  border-radius: 50%;
}

.phone-welcome {
  gap: 14px;
  padding: 18px;
  color: #fff;
  background: linear-gradient(135deg, var(--primary-dark), var(--primary-light));
  border-radius: 20px;
}

.phone-welcome > div:last-child,
.phone-card > div {
  min-width: 0;
}

.welcome-icon,
.card-icon {
  flex: 0 0 auto;
  display: grid;
  place-items: center;
  color: #fff;
  font-weight: 850;
}

.welcome-icon {
  width: 46px;
  height: 46px;
  background: rgba(255, 255, 255, 0.16);
  border: 1px solid rgba(255, 255, 255, 0.18);
  border-radius: 14px;
  font-size: 24px;
}

.phone-welcome p,
.phone-card p,
.feature-card p,
.privacy-list p,
.cta p {
  margin-bottom: 0;
}

.phone-welcome p {
  color: rgba(255, 255, 255, 0.78);
  font-size: 13px;
  line-height: 1.5;
}

.phone-section-title {
  margin: 24px 0 12px;
  font-size: 17px;
  font-weight: 850;
}

.phone-card {
  gap: 14px;
  margin-bottom: 12px;
  padding: 16px;
  background: var(--surface-muted);
  border: 1px solid rgba(57, 120, 183, 0.13);
  border-radius: 18px;
}

.card-icon {
  width: 42px;
  height: 42px;
  background: var(--primary);
  border-radius: 14px;
}

.phone-card.soft .card-icon {
  background: var(--secondary);
}

.phone-card p {
  color: var(--muted);
  font-size: 13px;
  line-height: 1.5;
}

.phone-stats {
  justify-content: space-between;
  gap: 12px;
  margin-top: 18px;
}

.phone-stats span {
  flex: 1;
  padding: 16px 12px;
  color: var(--muted);
  background: #eef6fb;
  border-radius: 16px;
  text-align: center;
}

.phone-stats b {
  display: block;
  color: var(--primary-dark);
  font-size: 26px;
  line-height: 1;
}

.section {
  width: var(--container);
  margin: 0 auto;
  padding: 72px 0;
}

.section-heading {
  max-width: 620px;
  margin-bottom: 28px;
}

.feature-grid,
.privacy-list {
  display: grid;
  gap: 16px;
}

.feature-grid {
  grid-template-columns: repeat(4, minmax(0, 1fr));
}

.feature-card,
.privacy-list article {
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: 8px;
}

.feature-card {
  min-height: 230px;
  padding: 24px;
  box-shadow: 0 12px 34px rgba(40, 94, 145, 0.07);
}

.feature-mark {
  display: inline-flex;
  margin-bottom: 28px;
  color: var(--accent);
  font-weight: 900;
}

.feature-card p,
.privacy-list {
  color: var(--muted);
}

.split-section {
  display: grid;
  grid-template-columns: 330px minmax(0, 1fr);
  gap: 36px;
  align-items: start;
  padding-top: 74px;
  border-top: 1px solid var(--border);
}

.privacy-list {
  grid-template-columns: repeat(3, minmax(0, 1fr));
}

.privacy-list article {
  min-height: 178px;
  padding: 22px;
  background: var(--surface-muted);
}

.privacy-list span {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  width: 42px;
  height: 42px;
  margin-bottom: 22px;
  color: var(--primary);
  background: #e4f0fa;
  border-radius: 50%;
  font-size: 14px;
  font-weight: 900;
}

.cta {
  width: var(--container);
  margin: 8px auto 0;
  justify-content: space-between;
  gap: 22px;
  padding: 34px;
  background: linear-gradient(135deg, #fff, #edf6fb);
  border: 1px solid var(--border);
  border-radius: 8px;
}

.cta > div {
  flex: 1;
  min-width: 0;
}

.cta h2 {
  margin-bottom: 8px;
}

.site-footer {
  margin-top: 56px;
  background: var(--background);
  border-top: 1px solid var(--border);
}

.footer-inner {
  display: block;
  padding: 34px 0 38px;
  color: var(--muted);
}

.footer-main {
  display: grid;
  grid-template-columns: minmax(260px, 360px) minmax(0, 1fr);
  gap: 42px;
  align-items: start;
}

.footer-brand {
  display: flex;
  align-items: center;
  gap: 14px;
}

.footer-brand img {
  flex: 0 0 auto;
  border-radius: 14px;
  box-shadow: 0 10px 24px rgba(40, 94, 145, 0.14);
}

.footer-brand strong,
.footer-brand span {
  display: block;
}

.footer-brand strong {
  color: var(--text);
  font-size: 18px;
  line-height: 1.25;
}

.footer-brand span {
  margin-top: 4px;
  font-size: 14px;
  line-height: 1.5;
}

.footer-company p,
.footer-record p {
  margin-bottom: 0;
}

.footer-company {
  display: grid;
  gap: 9px;
  min-width: 0;
}

.footer-company p {
  display: grid;
  grid-template-columns: 68px minmax(0, 1fr);
  gap: 14px;
  align-items: flex-start;
  min-width: 0;
  font-size: 15px;
  line-height: 1.6;
}

.footer-company span {
  color: var(--primary-dark);
  font-weight: 850;
}

.footer-company a:hover {
  color: var(--primary);
}

.footer-record {
  display: flex;
  flex-wrap: wrap;
  justify-content: space-between;
  gap: 8px 20px;
  margin-top: 28px;
  padding-top: 18px;
  border-top: 1px solid rgba(220, 231, 240, 0.9);
  font-size: 13px;
  line-height: 1.6;
}

@media (max-width: 980px) {
  .hero {
    grid-template-columns: 1fr;
    gap: 40px;
    padding-top: 56px;
  }

  .phone-preview {
    max-width: 420px;
    justify-self: center;
  }

  .feature-grid {
    grid-template-columns: repeat(2, minmax(0, 1fr));
  }

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

  .footer-main {
    grid-template-columns: 1fr;
    gap: 24px;
  }

  .privacy-list {
    grid-template-columns: 1fr;
  }

  .privacy-list article,
  .feature-card {
    min-height: auto;
  }
}

@media (max-width: 680px) {
  :root {
    --container: min(100vw - 32px, 1120px);
  }

  .header-inner {
    min-height: 62px;
  }

  .brand span {
    display: none;
  }

  .nav {
    gap: 16px;
    font-size: 14px;
  }

  .hero {
    padding: 42px 0 54px;
  }

  h1 {
    font-size: 38px;
  }

  .lead {
    font-size: 16px;
  }

  .hero-actions {
    align-items: stretch;
    flex-direction: column;
  }

  .button {
    width: 100%;
  }

  .phone-preview {
    max-width: none;
    overflow: hidden;
  }

  .feature-grid {
    grid-template-columns: 1fr;
  }

  .section {
    padding: 52px 0;
  }

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

  .cta {
    padding: 24px;
  }

  .footer-record {
    flex-direction: column;
  }
}

@media (max-width: 520px) {
  :root {
    --container: min(calc(100vw - 32px), 360px);
  }

  h1 {
    max-width: 8.5em;
    font-size: 36px;
    word-break: break-all;
  }

  .lead,
  .phone-welcome p,
  .phone-card p {
    word-break: break-all;
  }

  .footer-company p {
    grid-template-columns: 1fr;
    gap: 2px;
  }
}