:root {
  --ink: #18202f;
  --muted: #5f6878;
  --paper: #f7f9fc;
  --panel: #ffffff;
  --line: #dfe5ee;
  --blue: #1b5cff;
  --blue-dark: #1646bd;
  --teal: #0f766e;
  --soft-blue: #eef4ff;
  --shadow: 0 22px 70px rgba(28, 56, 101, 0.12);
}

* {
  box-sizing: border-box;
}

html {
  overflow-x: hidden;
  scroll-behavior: smooth;
}

body {
  margin: 0;
  min-width: 320px;
  overflow-x: hidden;
  color: var(--ink);
  background:
    radial-gradient(circle at 78% 12%, rgba(27, 92, 255, 0.08), transparent 26%),
    linear-gradient(180deg, #fbfcff 0%, var(--paper) 100%);
  font-family: Inter, ui-sans-serif, system-ui, -apple-system, BlinkMacSystemFont, "Segoe UI", "Microsoft YaHei", sans-serif;
  line-height: 1.6;
}

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

.site-header {
  position: sticky;
  top: 0;
  z-index: 20;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 24px;
  padding: 14px clamp(20px, 5vw, 64px);
  border-bottom: 1px solid var(--line);
  background: rgba(255, 255, 255, 0.9);
  backdrop-filter: blur(18px);
}

.brand,
.nav-links {
  display: flex;
  align-items: center;
}

.brand {
  min-width: 0;
  gap: 10px;
  font-size: 18px;
  font-weight: 900;
}

.brand img {
  flex: 0 0 auto;
  width: 40px;
  height: 40px;
  border-radius: 8px;
}

.nav-links {
  flex-wrap: wrap;
  justify-content: flex-end;
  gap: 18px;
  color: var(--muted);
  font-size: 15px;
}

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

.hero,
.section {
  padding-inline: clamp(20px, 5vw, 64px);
}

.hero {
  display: grid;
  grid-template-columns: minmax(0, 1fr) minmax(280px, 0.48fr);
  gap: clamp(28px, 6vw, 82px);
  align-items: center;
  min-height: 520px;
  padding-block: clamp(54px, 8vw, 104px);
}

.hero-copy {
  max-width: 780px;
}

.eyebrow {
  display: inline-flex;
  margin: 0 0 14px;
  color: var(--teal);
  font-size: 14px;
  font-weight: 900;
}

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

h1 {
  max-width: 780px;
  margin-bottom: 20px;
  font-size: clamp(42px, 6.2vw, 76px);
  line-height: 1.05;
  letter-spacing: 0;
}

h2 {
  margin-bottom: 12px;
  font-size: clamp(30px, 4vw, 48px);
  line-height: 1.1;
  letter-spacing: 0;
}

h3 {
  margin-bottom: 12px;
  font-size: 22px;
  line-height: 1.25;
}

.hero p,
.section-heading p,
.info-panel,
.article-card p {
  color: var(--muted);
}

.hero-copy > p {
  max-width: 680px;
  margin-bottom: 30px;
  font-size: 20px;
}

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

.primary-action,
.secondary-action,
.buy-button {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  min-height: 48px;
  border-radius: 8px;
  font-weight: 900;
}

.primary-action {
  padding: 0 24px;
  color: #ffffff;
  background: var(--blue);
  box-shadow: 0 14px 34px rgba(27, 92, 255, 0.24);
}

.primary-action:hover,
.buy-button:hover {
  background: var(--blue-dark);
}

.secondary-action {
  padding: 0 22px;
  border: 1px solid var(--line);
  background: rgba(255, 255, 255, 0.72);
}

.hero-panel,
.article-card,
.info-panel,
.modal-card {
  border: 1px solid var(--line);
  border-radius: 8px;
  background: rgba(255, 255, 255, 0.88);
  box-shadow: var(--shadow);
}

.hero-panel {
  display: grid;
  gap: 14px;
  padding: 28px;
}

.hero-panel strong {
  font-size: 22px;
}

.hero-panel span {
  padding: 14px 16px;
  border: 1px solid #d8e3f7;
  border-radius: 8px;
  background: var(--soft-blue);
  color: #263854;
  font-weight: 800;
}

.section {
  padding-block: clamp(44px, 7vw, 86px);
}

.section-heading {
  max-width: 820px;
  margin-bottom: 28px;
}

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

.article-card {
  display: grid;
  gap: 24px;
  align-content: space-between;
  min-height: 320px;
  padding: 24px;
}

.article-tag {
  display: inline-flex;
  margin-bottom: 14px;
  padding: 5px 9px;
  border-radius: 8px;
  color: var(--teal);
  background: rgba(15, 118, 110, 0.08);
  font-size: 13px;
  font-weight: 900;
}

.buy-button {
  width: 100%;
  border: 0;
  color: #ffffff;
  background: var(--blue);
  cursor: pointer;
  font: inherit;
}

.split-section {
  display: grid;
  grid-template-columns: minmax(260px, 0.58fr) minmax(0, 1fr);
  gap: clamp(26px, 5vw, 76px);
  align-items: start;
  border-top: 1px solid var(--line);
}

.info-panel {
  padding: 26px;
}

.info-panel p {
  margin-bottom: 12px;
}

.info-panel p:last-child {
  margin-bottom: 0;
}

.info-panel a {
  color: var(--blue);
  font-weight: 800;
}

.site-footer {
  display: flex;
  justify-content: space-between;
  gap: 18px;
  padding: 22px clamp(20px, 5vw, 64px);
  border-top: 1px solid var(--line);
  color: var(--muted);
  background: #ffffff;
}

.site-footer a {
  color: var(--muted);
  font-weight: 700;
}

.payment-modal[hidden] {
  display: none;
}

.payment-modal {
  position: fixed;
  inset: 0;
  z-index: 40;
  display: grid;
  place-items: center;
  padding: 20px;
}

.modal-backdrop {
  position: absolute;
  inset: 0;
  background: rgba(10, 19, 34, 0.48);
}

.modal-card {
  position: relative;
  z-index: 1;
  width: min(440px, 100%);
  padding: 26px;
  text-align: center;
}

.modal-card h2 {
  font-size: 28px;
}

.modal-card img {
  display: block;
  width: min(280px, 78vw);
  height: auto;
  margin: 18px auto;
  border: 1px solid var(--line);
  border-radius: 8px;
}

.payment-price {
  margin-bottom: 0;
  color: var(--blue);
  font-size: 20px;
  font-weight: 900;
}

.payment-note {
  margin-bottom: 0;
  color: var(--muted);
}

.modal-close {
  position: absolute;
  top: 12px;
  right: 12px;
  width: 34px;
  height: 34px;
  border: 1px solid var(--line);
  border-radius: 8px;
  background: #ffffff;
  color: var(--muted);
  cursor: pointer;
  font-size: 24px;
  line-height: 1;
}

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

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

  .article-card {
    min-height: auto;
  }
}

@media (max-width: 680px) {
  .site-header {
    align-items: flex-start;
    flex-direction: column;
    gap: 12px;
  }

  .nav-links {
    justify-content: flex-start;
    gap: 14px;
  }

  .hero {
    min-height: auto;
    padding-block: 42px;
  }

  .hero-copy > p {
    font-size: 17px;
  }

  .primary-action,
  .secondary-action {
    width: 100%;
  }

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