* {
  box-sizing: border-box;
}

html {
  scroll-behavior: smooth;
}

body {
  margin: 0;
  background: #f4f7fb;
  color: #1f2937;
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "Helvetica Neue", Arial, "PingFang SC", "Microsoft YaHei", sans-serif;
  line-height: 1.7;
}

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

.container {
  width: min(1180px, calc(100% - 40px));
  margin: 0 auto;
}

.site-header {
  position: sticky;
  top: 0;
  z-index: 20;
  background: rgba(255,255,255,.92);
  backdrop-filter: blur(14px);
  border-bottom: 1px solid #e5eaf3;
}

.header-inner {
  min-height: 76px;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 24px;
}

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

.brand-link {
  text-decoration: none;
}

.brand-logo {
  width: 46px;
  height: 46px;
  border-radius: 14px;
  background: linear-gradient(135deg, #2563eb, #60a5fa);
  color: #fff;
  font-weight: 900;
  font-size: 26px;
  display: grid;
  place-items: center;
  box-shadow: 0 10px 24px rgba(37,99,235,.25);
}

.brand-name {
  font-size: 18px;
  font-weight: 800;
  color: #111827;
}

.brand-sub {
  margin-top: 2px;
  font-size: 13px;
  color: #6b7280;
}

.nav {
  display: flex;
  gap: 22px;
  font-size: 15px;
  color: #374151;
}

.nav a:hover {
  color: #2563eb;
}

.hero {
  padding: 72px 0 54px;
}

.hero-grid {
  display: grid;
  grid-template-columns: 1.3fr .7fr;
  gap: 28px;
  align-items: stretch;
}

.hero-text,
.hero-card,
.product-card,
.contact-card,
.order-card {
  background: #fff;
  border: 1px solid #e5eaf3;
  border-radius: 24px;
  box-shadow: 0 18px 50px rgba(31,41,55,.06);
}

.hero-text {
  padding: 54px;
}

.tag,
.badge {
  display: inline-flex;
  align-items: center;
  height: 34px;
  padding: 0 14px;
  border-radius: 999px;
  background: #e8f1ff;
  color: #2563eb;
  font-weight: 800;
  font-size: 14px;
}

.hero h1 {
  margin: 22px 0 18px;
  font-size: 46px;
  line-height: 1.2;
  color: #111827;
  letter-spacing: -.04em;
}

.hero p {
  max-width: 760px;
  margin: 0;
  color: #4b5563;
  font-size: 18px;
}

.hero-actions {
  margin-top: 34px;
  display: flex;
  gap: 14px;
  flex-wrap: wrap;
}

.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  min-height: 44px;
  padding: 0 22px;
  border-radius: 999px;
  font-weight: 800;
  cursor: pointer;
  border: 1px solid transparent;
  transition: .18s ease;
}

.btn.primary {
  background: #2563eb;
  color: #fff;
  box-shadow: 0 10px 24px rgba(37,99,235,.2);
}

.btn.primary:hover {
  background: #1d4ed8;
}

.btn.ghost {
  background: #fff;
  border-color: #cbd5e1;
  color: #334155;
}

.btn.ghost:hover {
  border-color: #2563eb;
  color: #2563eb;
}

.btn.wide {
  width: 100%;
  margin-top: 20px;
}

.btn.big {
  min-height: 50px;
  padding: 0 30px;
  font-size: 16px;
}

.hero-card {
  padding: 34px;
  background: linear-gradient(180deg, #ffffff, #eef6ff);
}

.hero-card h3 {
  margin: 0 0 18px;
  font-size: 24px;
  color: #111827;
}

.hero-card ul {
  margin: 0;
  padding-left: 20px;
  color: #374151;
  font-size: 16px;
}

.hero-card li {
  margin: 10px 0;
}

.section {
  padding: 42px 0;
}

.section.light {
  background: #eef4fb;
  margin-top: 30px;
  padding: 64px 0;
}

.section-title {
  margin-bottom: 26px;
  border-left: 6px solid #2563eb;
  padding-left: 18px;
}

.section-title h2 {
  margin: 0 0 8px;
  font-size: 32px;
  color: #111827;
}

.section-title p {
  margin: 0;
  color: #6b7280;
  font-size: 17px;
}

.product-grid {
  display: grid;
  grid-template-columns: repeat(2, minmax(0,1fr));
  gap: 24px;
}

.product-card {
  padding: 34px;
  position: relative;
  overflow: hidden;
  background: linear-gradient(180deg, #f4f9ff, #ffffff 42%);
}

.product-card:after {
  content: "";
  position: absolute;
  right: -40px;
  top: -40px;
  width: 130px;
  height: 130px;
  border-radius: 50%;
  background: rgba(37,99,235,.08);
}

.product-card h3 {
  position: relative;
  z-index: 1;
  margin: 20px 0 18px;
  font-size: 26px;
  color: #1d4ed8;
}

.price {
  margin: 0 0 18px;
  color: #dc2626;
}

.price strong {
  font-size: 44px;
  letter-spacing: -.04em;
}

.price span {
  margin-left: 6px;
  color: #6b7280;
  font-size: 16px;
}

.desc {
  color: #374151;
  font-size: 17px;
  min-height: 72px;
}

.features {
  margin: 18px 0 0;
  padding-left: 20px;
  color: #1f2937;
  font-size: 16px;
}

.features li {
  margin: 8px 0;
}

.notice-box {
  margin-top: 24px;
  padding: 22px 24px;
  border: 1px solid #fed7aa;
  background: #fff7ed;
  color: #9a3412;
  border-radius: 18px;
  font-size: 16px;
}

.notice-box.compact {
  font-size: 14px;
  margin-top: 26px;
}

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

.step {
  background: #fff;
  border: 1px solid #e5eaf3;
  border-radius: 20px;
  padding: 24px;
}

.step span {
  width: 38px;
  height: 38px;
  display: grid;
  place-items: center;
  background: #2563eb;
  color: #fff;
  border-radius: 50%;
  font-weight: 900;
}

.step h3 {
  margin: 16px 0 8px;
  font-size: 20px;
}

.step p {
  margin: 0;
  color: #6b7280;
}

.contact-card {
  padding: 34px;
}

.contact-card h2 {
  margin: 0 0 10px;
  font-size: 28px;
}

.contact-card p {
  margin: 0 0 18px;
  color: #6b7280;
}

.contact-list {
  display: grid;
  gap: 10px;
  color: #374151;
}

.footer {
  margin-top: 30px;
  padding: 28px 0;
  background: #111827;
  color: #cbd5e1;
  font-size: 14px;
}

.footer-inner {
  display: flex;
  justify-content: space-between;
  gap: 18px;
  flex-wrap: wrap;
}

.order-wrap {
  display: flex;
  justify-content: center;
}

.order-card {
  width: min(820px, 100%);
  padding: 42px;
}

.order-card h1 {
  margin: 0 0 8px;
  font-size: 34px;
  text-align: center;
}

.order-sub {
  margin: 0 0 28px;
  text-align: center;
  color: #6b7280;
}

.order-info {
  border-top: 1px solid #e5e7eb;
}

.order-row {
  display: grid;
  grid-template-columns: 150px 1fr;
  gap: 18px;
  padding: 17px 0;
  border-bottom: 1px solid #e5e7eb;
}

.order-row span {
  color: #6b7280;
  font-weight: 700;
}

.order-row strong {
  color: #111827;
}

.order-price {
  color: #dc2626 !important;
  font-size: 28px;
}

.pay-section {
  margin-top: 30px;
}

.pay-section h2 {
  margin: 0 0 14px;
  font-size: 22px;
}

.pay-methods {
  display: flex;
  gap: 12px;
  flex-wrap: wrap;
}

.pay-btn {
  min-width: 130px;
  height: 44px;
  border-radius: 14px;
  border: 1px solid #cbd5e1;
  background: #fff;
  color: #374151;
  font-size: 16px;
  font-weight: 800;
  cursor: pointer;
}

.pay-btn.active {
  border-color: #2563eb;
  color: #2563eb;
  background: #eff6ff;
}

.order-actions {
  margin-top: 28px;
  display: flex;
  gap: 14px;
  justify-content: center;
  flex-wrap: wrap;
}

@media (max-width: 860px) {
  .header-inner {
    flex-direction: column;
    align-items: flex-start;
    padding: 16px 0;
  }

  .nav {
    flex-wrap: wrap;
    gap: 12px 18px;
  }

  .hero {
    padding-top: 34px;
  }

  .hero-grid,
  .product-grid,
  .steps {
    grid-template-columns: 1fr;
  }

  .hero-text {
    padding: 32px;
  }

  .hero h1 {
    font-size: 34px;
  }

  .order-row {
    grid-template-columns: 1fr;
    gap: 4px;
  }
}

.buyer-section {
  margin-top: 30px;
}

.buyer-section h2 {
  margin: 0 0 8px;
  font-size: 22px;
}

.buyer-tip {
  margin: 0 0 16px;
  color: #6b7280;
  font-size: 15px;
}

.input-label {
  display: block;
  margin-bottom: 8px;
  color: #374151;
  font-weight: 800;
}

.text-input {
  width: 100%;
  max-width: 420px;
  height: 48px;
  border: 1px solid #cbd5e1;
  border-radius: 14px;
  padding: 0 16px;
  font-size: 17px;
  outline: none;
  background: #fff;
  color: #111827;
}

.text-input:focus {
  border-color: #2563eb;
  box-shadow: 0 0 0 4px rgba(37,99,235,.12);
}

.form-error {
  min-height: 24px;
  margin-top: 8px;
  color: #dc2626;
  font-size: 14px;
  font-weight: 700;
}