:root {
  --brand-900: #0a2f6b;
  --brand-800: #123f8f;
  --brand-700: #1858c8;
  --brand-600: #2563eb;
  --brand-500: #3b82f6;
  --brand-100: #dbeafe;
  --brand-50: #eff6ff;
  --ink-900: #0f172a;
  --ink-700: #334155;
  --ink-500: #64748b;
  --line: rgba(148, 163, 184, 0.22);
  --surface: #ffffff;
  --surface-soft: rgba(255, 255, 255, 0.78);
  --bg: #f4f8ff;
  --success: #0f9f6e;
  --shadow-lg: 0 24px 60px rgba(15, 23, 42, 0.12);
  --shadow-md: 0 16px 36px rgba(15, 23, 42, 0.08);
  --radius-xl: 28px;
  --radius-lg: 22px;
  --radius-md: 16px;
  --container: 1200px;
}

* {
  box-sizing: border-box;
}

html {
  scroll-behavior: smooth;
}

body {
  margin: 0;
  font-family: "Microsoft YaHei", "PingFang SC", "Segoe UI", sans-serif;
  color: var(--ink-900);
  background:
    radial-gradient(circle at top left, rgba(37, 99, 235, 0.16), transparent 28%),
    radial-gradient(circle at top right, rgba(30, 64, 175, 0.12), transparent 24%),
    linear-gradient(180deg, #f8fbff 0%, #eef4ff 100%);
}

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

button {
  font: inherit;
}

.intro-shell {
  min-height: 100vh;
}

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

.intro-topbar {
  position: sticky;
  top: 0;
  z-index: 20;
  backdrop-filter: blur(18px);
  background: rgba(255, 255, 255, 0.72);
  border-bottom: 1px solid rgba(148, 163, 184, 0.16);
}

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

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

.intro-brand-mark {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  width: 42px;
  height: 42px;
  border-radius: 14px;
  background: linear-gradient(135deg, var(--brand-800), var(--brand-500));
  color: #fff;
  font-size: 18px;
  font-weight: 700;
  box-shadow: 0 12px 24px rgba(37, 99, 235, 0.22);
}

.intro-brand-text {
  display: flex;
  flex-direction: column;
  gap: 4px;
}

.intro-brand-title {
  font-size: 18px;
  font-weight: 700;
  letter-spacing: 0.02em;
}

.intro-brand-subtitle {
  color: var(--ink-500);
  font-size: 12px;
}

.intro-nav {
  display: flex;
  align-items: center;
  gap: 8px;
}

.intro-nav a {
  padding: 10px 14px;
  border-radius: 999px;
  color: var(--ink-700);
  font-size: 14px;
  transition: background-color 0.2s ease, color 0.2s ease;
}

.intro-nav a:hover,
.intro-nav a.is-active {
  background: rgba(37, 99, 235, 0.1);
  color: var(--brand-700);
}

.intro-topbar-actions {
  display: flex;
  align-items: center;
  gap: 12px;
}

.intro-menu-button {
  display: none;
  width: 42px;
  height: 42px;
  border: 0;
  border-radius: 14px;
  background: rgba(37, 99, 235, 0.1);
  color: var(--brand-700);
}

.intro-menu-button span {
  display: block;
  width: 18px;
  height: 2px;
  margin: 3px auto;
  border-radius: 999px;
  background: currentColor;
}

.intro-button,
.intro-button-secondary {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 8px;
  min-height: 46px;
  padding: 0 20px;
  border-radius: 999px;
  font-size: 14px;
  font-weight: 600;
  transition: transform 0.2s ease, box-shadow 0.2s ease, background-color 0.2s ease;
}

.intro-button {
  background: linear-gradient(135deg, var(--brand-800), var(--brand-500));
  color: #fff;
  box-shadow: 0 16px 32px rgba(37, 99, 235, 0.28);
}

.intro-button:hover,
.intro-button-secondary:hover {
  transform: translateY(-1px);
}

.intro-button-secondary {
  border: 1px solid rgba(37, 99, 235, 0.18);
  background: rgba(255, 255, 255, 0.76);
  color: var(--brand-700);
}

.intro-hero {
  position: relative;
  padding: 56px 0 42px;
}

.intro-hero-grid {
  display: grid;
  grid-template-columns: minmax(0, 1.12fr) minmax(320px, 0.88fr);
  gap: 28px;
  align-items: stretch;
}

.intro-hero-copy,
.intro-card,
.intro-section-panel,
.intro-page-hero,
.intro-page-panel {
  border: 1px solid rgba(255, 255, 255, 0.76);
  background: linear-gradient(180deg, rgba(255, 255, 255, 0.92), rgba(255, 255, 255, 0.8));
  border-radius: var(--radius-xl);
  box-shadow: var(--shadow-md);
}

.intro-hero-copy {
  padding: 44px;
}

.intro-eyebrow {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  margin-bottom: 18px;
  padding: 7px 12px;
  border-radius: 999px;
  background: rgba(37, 99, 235, 0.1);
  color: var(--brand-700);
  font-size: 13px;
  font-weight: 600;
}

.intro-hero h1,
.intro-page-hero h1 {
  margin: 0;
  font-size: clamp(34px, 4vw, 58px);
  line-height: 1.08;
  letter-spacing: -0.03em;
}

.intro-gradient-text {
  background: linear-gradient(135deg, var(--brand-900), var(--brand-500));
  -webkit-background-clip: text;
  background-clip: text;
  color: transparent;
}

.intro-lead {
  margin: 22px 0 0;
  color: var(--ink-700);
  font-size: 17px;
  line-height: 1.9;
}

.intro-hero-actions,
.intro-section-actions {
  display: flex;
  flex-wrap: wrap;
  gap: 12px;
  margin-top: 28px;
}

.intro-metrics {
  display: grid;
  grid-template-columns: repeat(3, minmax(0, 1fr));
  gap: 14px;
  margin-top: 34px;
}

.intro-metric {
  padding: 18px 18px 16px;
  border-radius: var(--radius-md);
  background: rgba(15, 23, 42, 0.03);
  border: 1px solid rgba(148, 163, 184, 0.14);
}

.intro-metric strong {
  display: block;
  margin-bottom: 6px;
  font-size: 28px;
  color: var(--brand-800);
}

.intro-metric span {
  color: var(--ink-500);
  font-size: 13px;
}

.intro-hero-visual {
  position: relative;
  overflow: hidden;
  padding: 10px;
  border-radius: var(--radius-xl);
  border: 1px solid rgba(255, 255, 255, 0.76);
  background: linear-gradient(180deg, rgba(255, 255, 255, 0.94), rgba(219, 234, 254, 0.72));
  box-shadow: var(--shadow-lg);
}

.intro-hero-visual img {
  display: block;
  width: 100%;
  height: 100%;
  min-height: 340px;
  object-fit: cover;
  border-radius: calc(var(--radius-xl) - 10px);
}

.intro-hero-visual-caption {
  position: absolute;
  right: 22px;
  bottom: 22px;
  left: 22px;
  padding: 16px 18px;
  border-radius: 18px;
  background: rgba(10, 47, 107, 0.84);
  backdrop-filter: blur(8px);
  color: #fff;
}

.intro-hero-visual-caption strong {
  display: block;
  margin-bottom: 6px;
  font-size: 15px;
}

.intro-hero-visual-caption span {
  display: block;
  color: rgba(255, 255, 255, 0.8);
  font-size: 13px;
  line-height: 1.7;
}

.intro-section {
  padding: 26px 0;
}

.intro-section-heading {
  display: flex;
  align-items: end;
  justify-content: space-between;
  gap: 20px;
  margin-bottom: 18px;
}

.intro-section-heading h2 {
  margin: 0;
  font-size: clamp(28px, 3vw, 40px);
  letter-spacing: -0.02em;
}

.intro-section-heading p {
  margin: 10px 0 0;
  max-width: 720px;
  color: var(--ink-500);
  line-height: 1.9;
}

.intro-grid-3,
.intro-grid-4,
.intro-grid-2 {
  display: grid;
  gap: 18px;
}

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

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

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

.intro-card,
.intro-section-panel,
.intro-page-panel {
  padding: 26px;
}

.intro-card-tag {
  display: inline-flex;
  margin-bottom: 14px;
  padding: 6px 10px;
  border-radius: 999px;
  background: var(--brand-50);
  color: var(--brand-700);
  font-size: 12px;
  font-weight: 700;
}

.intro-card h3,
.intro-page-panel h3 {
  margin: 0 0 12px;
  font-size: 20px;
}

.intro-card p,
.intro-page-panel p,
.intro-list li,
.intro-timeline-content p {
  color: var(--ink-500);
  line-height: 1.85;
}

.intro-card ul,
.intro-list {
  margin: 14px 0 0;
  padding-left: 18px;
}

.intro-card li,
.intro-list li {
  margin-bottom: 10px;
}

.intro-highlight-grid {
  display: grid;
  grid-template-columns: minmax(0, 1.08fr) minmax(0, 0.92fr);
  gap: 18px;
}

.intro-highlight-panel {
  min-height: 100%;
  padding: 30px;
  border-radius: var(--radius-xl);
  background: linear-gradient(180deg, rgba(255, 255, 255, 0.88), rgba(219, 234, 254, 0.76));
  border: 1px solid rgba(37, 99, 235, 0.14);
  box-shadow: var(--shadow-md);
}

.intro-highlight-panel h3 {
  margin: 0 0 12px;
  font-size: 24px;
}

.intro-highlight-panel p {
  margin: 0;
  color: var(--ink-500);
  line-height: 1.9;
}

.intro-feature-list {
  display: grid;
  gap: 14px;
  margin-top: 24px;
}

.intro-feature-item {
  display: grid;
  grid-template-columns: 42px minmax(0, 1fr);
  gap: 14px;
  align-items: start;
}

.intro-feature-icon {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  width: 42px;
  height: 42px;
  border-radius: 14px;
  background: rgba(37, 99, 235, 0.12);
  color: var(--brand-700);
  font-size: 18px;
  font-weight: 700;
}

.intro-feature-item strong {
  display: block;
  margin-bottom: 6px;
  font-size: 16px;
}

.intro-strip {
  margin-top: 20px;
  padding: 14px 18px;
  border-radius: 18px;
  background: rgba(15, 23, 42, 0.04);
  color: var(--ink-700);
  line-height: 1.8;
}

.intro-timeline {
  display: grid;
  gap: 16px;
}

.intro-timeline-item {
  display: grid;
  grid-template-columns: 84px minmax(0, 1fr);
  gap: 16px;
  align-items: start;
}

.intro-timeline-step {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  min-height: 42px;
  padding: 0 14px;
  border-radius: 999px;
  background: linear-gradient(135deg, var(--brand-800), var(--brand-500));
  color: #fff;
  font-size: 13px;
  font-weight: 700;
}

.intro-timeline-content {
  padding: 18px 20px;
  border-radius: 18px;
  background: rgba(255, 255, 255, 0.74);
  border: 1px solid rgba(148, 163, 184, 0.18);
}

.intro-timeline-content strong {
  display: block;
  margin-bottom: 8px;
  font-size: 17px;
}

.intro-page-hero {
  padding: 34px;
  margin: 38px 0 20px;
}

.intro-page-hero p {
  margin: 18px 0 0;
  max-width: 860px;
  color: var(--ink-500);
  font-size: 16px;
  line-height: 1.9;
}

.intro-page-panel {
  height: 100%;
}

.intro-page-panel-header {
  margin-bottom: 14px;
}

.intro-page-panel-header strong {
  display: block;
  margin-bottom: 6px;
  color: var(--brand-700);
  font-size: 13px;
  letter-spacing: 0.04em;
}

.intro-check-list,
.intro-tag-list {
  display: flex;
  flex-wrap: wrap;
  gap: 10px;
  margin-top: 16px;
}

.intro-check-item,
.intro-tag {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  padding: 9px 12px;
  border-radius: 999px;
  background: rgba(37, 99, 235, 0.08);
  color: var(--brand-700);
  font-size: 13px;
  font-weight: 600;
}

.intro-check-item::before {
  content: "✓";
  color: var(--success);
}

.intro-cta {
  padding: 26px 0 72px;
}

.intro-cta-panel {
  display: grid;
  grid-template-columns: minmax(0, 1fr) auto;
  gap: 20px;
  align-items: center;
  padding: 34px;
  border-radius: 30px;
  background: linear-gradient(135deg, var(--brand-900), var(--brand-700));
  color: #fff;
  box-shadow: 0 24px 60px rgba(15, 23, 42, 0.18);
}

.intro-cta-panel h2 {
  margin: 0;
  font-size: clamp(28px, 3vw, 42px);
}

.intro-cta-panel p {
  margin: 12px 0 0;
  max-width: 760px;
  color: rgba(255, 255, 255, 0.78);
  line-height: 1.85;
}

.intro-cta-panel .intro-button-secondary {
  background: rgba(255, 255, 255, 0.14);
  border-color: rgba(255, 255, 255, 0.22);
  color: #fff;
}

.intro-media-figure {
  margin: 0;
  overflow: hidden;
  border-radius: var(--radius-xl);
  border: 1px solid rgba(255, 255, 255, 0.76);
  background: rgba(255, 255, 255, 0.82);
  box-shadow: var(--shadow-md);
}

.intro-media-figure img {
  display: block;
  width: 100%;
  aspect-ratio: 16 / 9;
  object-fit: cover;
}

.intro-media-figure figcaption {
  padding: 16px 22px;
  color: var(--ink-500);
  font-size: 13px;
  line-height: 1.7;
}

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

.intro-scene-card {
  display: flex;
  flex-direction: column;
  overflow: hidden;
  border-radius: var(--radius-xl);
  border: 1px solid rgba(255, 255, 255, 0.76);
  background: linear-gradient(180deg, rgba(255, 255, 255, 0.94), rgba(255, 255, 255, 0.82));
  box-shadow: var(--shadow-md);
}

.intro-scene-media {
  overflow: hidden;
}

.intro-scene-media img {
  display: block;
  width: 100%;
  aspect-ratio: 4 / 3;
  object-fit: cover;
  transition: transform 0.4s ease;
}

.intro-scene-card:hover .intro-scene-media img {
  transform: scale(1.04);
}

.intro-scene-body {
  display: flex;
  flex: 1;
  flex-direction: column;
  gap: 10px;
  padding: 24px;
}

.intro-scene-body h3 {
  margin: 0;
  font-size: 19px;
}

.intro-scene-body p {
  margin: 0;
  color: var(--ink-500);
  line-height: 1.85;
}

.intro-scene-body a {
  margin-top: auto;
  color: var(--brand-700);
  font-size: 14px;
  font-weight: 600;
}

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

.intro-plan-card {
  display: flex;
  flex-direction: column;
  padding: 26px;
  border-radius: var(--radius-xl);
  border: 1px solid rgba(148, 163, 184, 0.2);
  background: rgba(255, 255, 255, 0.9);
  box-shadow: var(--shadow-md);
}

.intro-plan-card.is-featured {
  border-color: rgba(37, 99, 235, 0.42);
  background: linear-gradient(180deg, rgba(255, 255, 255, 0.98), rgba(219, 234, 254, 0.8));
  box-shadow: var(--shadow-lg);
}

.intro-plan-head {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 10px;
  margin-bottom: 14px;
}

.intro-plan-head h3 {
  margin: 0;
  font-size: 19px;
}

.intro-plan-badge {
  padding: 5px 10px;
  border-radius: 999px;
  background: linear-gradient(135deg, var(--brand-800), var(--brand-500));
  color: #fff;
  font-size: 12px;
  font-weight: 700;
}

.intro-plan-price {
  display: flex;
  align-items: baseline;
  gap: 6px;
  margin-bottom: 8px;
}

.intro-plan-price strong {
  color: var(--brand-800);
  font-size: 34px;
  letter-spacing: -0.02em;
}

.intro-plan-price span {
  color: var(--ink-500);
  font-size: 13px;
}

.intro-plan-desc {
  margin: 0 0 18px;
  color: var(--ink-500);
  font-size: 14px;
  line-height: 1.7;
}

.intro-plan-features {
  display: grid;
  gap: 10px;
  margin: 0;
  padding: 0;
  list-style: none;
}

.intro-plan-features li {
  display: grid;
  grid-template-columns: 16px minmax(0, 1fr);
  gap: 10px;
  color: var(--ink-700);
  font-size: 14px;
  line-height: 1.7;
}

.intro-plan-features li::before {
  content: "✓";
  color: var(--brand-600);
  font-weight: 700;
}

.intro-plan-note {
  margin: 18px 0 0;
  color: var(--ink-500);
  font-size: 13px;
  line-height: 1.8;
}

.intro-footer {
  padding: 0 0 42px;
}

.intro-footer-inner {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  justify-content: space-between;
  gap: 14px 24px;
  padding-top: 24px;
  border-top: 1px solid rgba(148, 163, 184, 0.22);
  color: var(--ink-500);
  font-size: 14px;
}

.intro-footer-links {
  display: flex;
  flex-wrap: wrap;
  gap: 18px;
}

.intro-footer a:hover {
  color: var(--brand-700);
}

.intro-mobile-menu {
  display: none;
}

@media (max-width: 1100px) {
  .intro-hero-grid,
  .intro-highlight-grid,
  .intro-grid-4 {
    grid-template-columns: 1fr;
  }

  .intro-grid-3 {
    grid-template-columns: repeat(2, minmax(0, 1fr));
  }

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

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

@media (max-width: 800px) {
  .intro-container {
    width: min(calc(100% - 28px), var(--container));
  }

  .intro-topbar-inner {
    min-height: 68px;
  }

  .intro-nav {
    display: none;
  }

  .intro-menu-button {
    display: inline-flex;
    align-items: center;
    justify-content: center;
  }

  .intro-topbar-actions .intro-button-secondary {
    display: none;
  }

  .intro-mobile-menu {
    display: grid;
    gap: 10px;
    padding: 0 0 18px;
  }

  .intro-mobile-menu.hidden {
    display: none;
  }

  .intro-mobile-menu a {
    padding: 12px 14px;
    border-radius: 16px;
    background: rgba(255, 255, 255, 0.76);
    color: var(--ink-700);
    border: 1px solid rgba(148, 163, 184, 0.16);
  }

  .intro-hero-copy,
  .intro-card,
  .intro-section-panel,
  .intro-page-hero,
  .intro-page-panel,
  .intro-highlight-panel,
  .intro-cta-panel {
    padding: 24px;
    border-radius: 24px;
  }

  .intro-grid-3,
  .intro-grid-2,
  .intro-scene-grid,
  .intro-plan-grid,
  .intro-metrics {
    grid-template-columns: 1fr;
  }

  .intro-hero-visual img {
    min-height: 240px;
  }

  .intro-section-heading,
  .intro-cta-panel {
    grid-template-columns: 1fr;
    display: grid;
    align-items: start;
  }

  .intro-timeline-item {
    grid-template-columns: 1fr;
    gap: 10px;
  }

  .intro-footer-inner {
    flex-direction: column;
    align-items: flex-start;
  }
}

@media (max-width: 560px) {
  .intro-topbar-actions {
    gap: 8px;
  }

  .intro-button,
  .intro-button-secondary {
    width: 100%;
  }

  .intro-hero-actions,
  .intro-section-actions {
    flex-direction: column;
  }

  .intro-brand-title {
    font-size: 16px;
  }

  .intro-brand-subtitle {
    font-size: 11px;
  }
}