* {
  box-sizing: border-box;
}

html {
  scroll-behavior: smooth;
}

body {
  margin: 0;
  font-family: "Microsoft YaHei", "PingFang SC", sans-serif;
  background: #f3f4f7;
  color: #1d2433;
}

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

.container {
  width: min(1160px, calc(100% - 48px));
  margin: 0 auto;
}

.site-header {
  position: sticky;
  top: 0;
  z-index: 20;
  background: rgba(255, 255, 255, 0.96);
  border-bottom: 1px solid rgba(12, 122, 219, 0.08);
  backdrop-filter: blur(12px);
}

.header-inner {
  display: flex;
  align-items: center;
  justify-content: space-between;
  min-height: 76px;
}

.brand {
  display: inline-flex;
  align-items: center;
  gap: 12px;
  font-weight: 700;
  color: #0b8edc;
}

.brand-mark {
  width: 34px;
  height: 34px;
  display: block;
  object-fit: contain;
}

.brand-text {
  font-size: 26px;
}

.nav {
  display: flex;
  gap: 30px;
  font-size: 15px;
  color: #4d5b74;
}

.nav a:hover {
  color: #0b8edc;
}

.hero {
  padding: 56px 0 82px;
  background: linear-gradient(180deg, #ffffff 0%, #f5f6f9 100%);
}

.hero-grid {
  display: grid;
  grid-template-columns: 1.08fr 0.92fr;
  align-items: center;
  gap: 56px;
}

.hero-visual {
  display: flex;
  align-items: center;
  justify-content: center;
}

.hero-image {
  width: 100%;
  max-width: 680px;
  height: auto;
  display: block;
  object-fit: contain;
  filter: drop-shadow(0 22px 36px rgba(31, 39, 51, 0.18));
}

.eyebrow {
  margin: 0 0 16px;
  color: #0b8edc;
  font-weight: 700;
  letter-spacing: 0.08em;
}

.hero-copy h1 {
  margin: 0 0 20px;
  font-size: clamp(40px, 5vw, 56px);
  line-height: 1.1;
}

.lead {
  margin: 0 0 28px;
  font-size: 17px;
  line-height: 1.9;
  color: #5d6a80;
}

.download-list {
  display: grid;
  gap: 16px;
  max-width: 420px;
}

.download-btn {
  display: flex;
  align-items: center;
  justify-content: center;
  min-height: 62px;
  border-radius: 14px;
  background: linear-gradient(135deg, #0a93e3, #1376d8);
  color: #fff;
  font-size: 18px;
  font-weight: 700;
  box-shadow: 0 16px 24px rgba(10, 147, 227, 0.2);
  transition: transform 0.2s ease, box-shadow 0.2s ease;
}

.download-btn:hover {
  transform: translateY(-2px);
  box-shadow: 0 20px 28px rgba(10, 147, 227, 0.26);
}

.features {
  padding: 92px 0;
}

.features h2,
.guide-card h2 {
  margin: 0 0 38px;
  font-size: clamp(30px, 4vw, 42px);
  text-align: center;
}

.feature-grid {
  display: grid;
  grid-template-columns: repeat(3, minmax(0, 1fr));
  gap: 30px;
}

.feature-card {
  padding: 34px 28px;
  border-radius: 22px;
  background: #fff;
  text-align: center;
  box-shadow: 0 20px 36px rgba(18, 34, 68, 0.06);
}

.feature-icon {
  width: 92px;
  height: 92px;
  margin: 0 auto 22px;
  display: block;
  object-fit: contain;
}

.feature-card h3 {
  margin: 0 0 14px;
  color: #0b8edc;
  font-size: 27px;
  line-height: 1.3;
}

.feature-card p,
.faq-item p,
.step-list p {
  margin: 0;
  color: #66758c;
  line-height: 1.85;
  font-size: 16px;
}

.guide-section {
  padding: 94px 0;
  background: #fff;
}

.dual-grid {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 36px;
}

.guide-card {
  padding: 42px 34px;
  border-radius: 24px;
  background: #f7f9fc;
  box-shadow: 0 18px 34px rgba(20, 32, 62, 0.05);
}

.guide-card h2 {
  text-align: left;
  margin-bottom: 30px;
  position: relative;
  padding-left: 18px;
}

.guide-card h2::before {
  content: "";
  position: absolute;
  left: 0;
  top: 8px;
  width: 6px;
  height: calc(100% - 16px);
  border-radius: 99px;
  background: linear-gradient(180deg, #0ba0ef, #1376d8);
}

.step-list {
  list-style: none;
  margin: 0;
  padding: 0;
  counter-reset: step;
}

.step-list li {
  position: relative;
  padding-left: 74px;
  margin-bottom: 28px;
}

.step-list li:last-child {
  margin-bottom: 0;
}

.step-list li::before {
  counter-increment: step;
  content: counter(step);
  position: absolute;
  left: 0;
  top: 0;
  width: 42px;
  height: 42px;
  display: flex;
  align-items: center;
  justify-content: center;
  border-radius: 50%;
  background: linear-gradient(135deg, #0aa5f0, #1977d4);
  color: #fff;
  font-weight: 700;
}

.step-list strong,
.faq-item h3 {
  display: block;
  margin-bottom: 8px;
  font-size: 22px;
  line-height: 1.45;
  color: #243149;
}

.faq-item {
  padding: 0 0 22px;
  margin-bottom: 22px;
  border-bottom: 1px solid #e3eaf3;
}

.faq-item:last-child {
  margin-bottom: 0;
  padding-bottom: 0;
  border-bottom: none;
}

.site-footer {
  padding: 28px 0 36px;
  background: #fff;
  border-top: 1px solid #e8edf5;
}

.site-footer p {
  margin: 0;
  text-align: center;
  color: #7988a1;
}

@media (max-width: 980px) {
  .hero-grid,
  .dual-grid,
  .feature-grid {
    grid-template-columns: 1fr;
  }

  .hero-copy {
    text-align: center;
  }

  .download-list {
    margin: 0 auto;
  }
}

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

  .header-inner {
    min-height: 66px;
  }

  .brand-text {
    font-size: 22px;
  }

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

  .hero {
    padding-top: 28px;
  }

  .hero-copy h1 {
    font-size: 36px;
  }

  .lead,
  .feature-card p,
  .faq-item p,
  .step-list p {
    font-size: 15px;
  }

  .feature-card h3,
  .step-list strong,
  .faq-item h3 {
    font-size: 20px;
  }

  .guide-card {
    padding: 30px 22px;
  }
}