:root {
  --bg: #f4f7fb;
  --bg-strong: #eaf1ff;
  --card: rgba(255, 255, 255, 0.78);
  --card-strong: #ffffff;
  --text: #162033;
  --text-soft: #53627b;
  --primary: #2d6df6;
  --primary-strong: #1f4fd6;
  --primary-soft: rgba(45, 109, 246, 0.12);
  --accent: #13b38b;
  --warning: #ffb020;
  --border: rgba(120, 140, 170, 0.2);
  --shadow: 0 18px 45px rgba(20, 38, 74, 0.08);
}

body.dark {
  --bg: #0f172a;
  --bg-strong: #111c33;
  --card: rgba(15, 23, 42, 0.82);
  --card-strong: #17223c;
  --text: #ebf3ff;
  --text-soft: #b8c4dd;
  --primary: #7aa8ff;
  --primary-strong: #8ec5ff;
  --primary-soft: rgba(122, 168, 255, 0.16);
  --accent: #4fe0bd;
  --warning: #ffc75c;
  --border: rgba(160, 178, 214, 0.18);
  --shadow: 0 20px 50px rgba(2, 8, 16, 0.45);
}

* {
  box-sizing: border-box;
}

html {
  scroll-behavior: smooth;
}

body {
  margin: 0;
  font-family: 'Noto Sans SC', 'Inter', sans-serif;
  background:
    radial-gradient(circle at top left, rgba(45, 109, 246, 0.16), transparent 28%),
    linear-gradient(180deg, var(--bg-strong) 0%, var(--bg) 28%, var(--bg) 100%);
  color: var(--text);
  min-height: 100vh;
  transition: background 0.25s ease, color 0.25s ease;
}

.page-shell {
  max-width: 1180px;
  margin: 0 auto;
  padding: 32px 20px 72px;
}

.customer-float {
  position: fixed;
  right: 22px;
  top: 50%;
  transform: translateY(-50%);
  z-index: 60;
  display: inline-flex;
  align-items: center;
  gap: 8px;
  padding: 12px 16px;
  border-radius: 999px;
  background: linear-gradient(135deg, var(--primary) 0%, var(--accent) 100%);
  color: #fff;
  text-decoration: none;
  box-shadow: 0 18px 32px rgba(45, 109, 246, 0.28);
  border: 1px solid rgba(255, 255, 255, 0.18);
  transition: transform 0.2s ease, box-shadow 0.2s ease;
}

.customer-float:hover {
  transform: translateY(-50%) translateX(-2px);
  box-shadow: 0 22px 40px rgba(45, 109, 246, 0.35);
}

.customer-icon {
  display: inline-flex;
  width: 28px;
  height: 28px;
  align-items: center;
  justify-content: center;
  border-radius: 50%;
  background: rgba(255, 255, 255, 0.18);
  font-size: 1rem;
  font-weight: 700;
}

.customer-text {
  font-size: 0.9rem;
  font-weight: 700;
  letter-spacing: 0.04em;
}

.page-nav {
  position: sticky;
  top: 16px;
  z-index: 20;
  display: flex;
  flex-wrap: wrap;
  justify-content: center;
  gap: 10px;
  padding: 10px 16px;
  margin: 0 auto 24px;
  max-width: 720px;
}

.page-nav a {
  text-decoration: none;
  color: var(--text-soft);
  background: rgba(255, 255, 255, 0.26);
  border: 1px solid var(--border);
  border-radius: 999px;
  padding: 8px 14px;
  font-size: 0.85rem;
  transition: all 0.2s ease;
}

.page-nav a:hover {
  color: var(--primary-strong);
  border-color: rgba(45, 109, 246, 0.4);
}

.topbar {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 16px;
  padding: 12px 8px 20px;
}

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

.brand-mark {
  width: 52px;
  height: 52px;
  border-radius: 16px;
  background: linear-gradient(135deg, var(--primary) 0%, var(--accent) 100%);
  display: grid;
  place-items: center;
  color: white;
  font-size: 1.8rem;
  font-weight: 800;
  box-shadow: var(--shadow);
}

.brand-label {
  margin: 0;
  font-size: 0.72rem;
  letter-spacing: 0.12em;
  text-transform: uppercase;
  color: var(--text-soft);
}

h1 {
  margin: 4px 0 0;
  font-size: clamp(1.5rem, 2vw, 2.2rem);
}

.download-group {
  display: flex;
  align-items: center;
  gap: 12px;
  flex-wrap: wrap;
}

.download-btn {
  display: inline-flex;
  align-items: center;
  gap: 10px;
  padding: 10px 14px;
  border-radius: 14px;
  text-decoration: none;
  color: #fff;
  box-shadow: var(--shadow);
  border: 1px solid rgba(255,255,255,0.2);
  transition: transform 0.2s ease, box-shadow 0.2s ease;
}

.download-btn:hover {
  transform: translateY(-1px);
}

.download-btn.android {
  background: linear-gradient(135deg, #1ecf8a 0%, #13b38b 100%);
}

.download-btn.ios {
  background: linear-gradient(135deg, #2d6df6 0%, #4a8bff 100%);
}

.download-icon {
  display: inline-flex;
  width: 28px;
  height: 28px;
  align-items: center;
  justify-content: center;
  border-radius: 9px;
  background: rgba(255,255,255,0.16);
  font-size: 1rem;
  font-weight: 700;
}

.download-btn small {
  display: block;
  font-size: 0.62rem;
  opacity: 0.9;
  letter-spacing: 0.04em;
}

.download-btn strong {
  display: block;
  font-size: 0.92rem;
  line-height: 1.2;
}

.container {
  display: grid;
  gap: 28px;
}

.card {
  background: var(--card);
  backdrop-filter: blur(14px);
  -webkit-backdrop-filter: blur(14px);
  border: 1px solid var(--border);
  box-shadow: var(--shadow);
  border-radius: 28px;
}

.hero {
  display: grid;
  grid-template-columns: 1.5fr 0.8fr;
  gap: 26px;
  padding: 32px;
}

.eyebrow,
.section-kicker {
  display: inline-block;
  padding: 6px 10px;
  border-radius: 999px;
  font-size: 0.72rem;
  font-weight: 700;
  letter-spacing: 0.08em;
  text-transform: uppercase;
  color: var(--primary-strong);
  background: var(--primary-soft);
}

.hero-copy h2 {
  margin: 18px 0 12px;
  font-size: clamp(2rem, 3vw, 3rem);
  line-height: 1.2;
}

.hero-copy p {
  margin: 0;
  color: var(--text-soft);
  line-height: 1.8;
  max-width: 620px;
  font-size: 1.02rem;
}

.hero-tags {
  display: flex;
  flex-wrap: wrap;
  gap: 12px;
  margin-top: 22px;
}

.hero-tags span {
  padding: 8px 12px;
  border-radius: 999px;
  border: 1px solid var(--border);
  background: rgba(255, 255, 255, 0.3);
  color: var(--text-soft);
  font-size: 0.86rem;
}

.hero-panel {
  display: grid;
  gap: 16px;
  align-content: center;
}

.mini-stat {
  background: linear-gradient(135deg, rgba(45, 109, 246, 0.08), rgba(19, 179, 139, 0.08));
  border: 1px solid var(--border);
  border-radius: 20px;
  padding: 18px 20px;
  display: grid;
  gap: 8px;
}

.mini-stat strong {
  color: var(--primary-strong);
  font-size: 0.8rem;
  letter-spacing: 0.08em;
  text-transform: uppercase;
}

.mini-stat span {
  font-size: 1.05rem;
  font-weight: 600;
}

.section-block {
  display: grid;
  gap: 18px;
}

.segmented {
  background: var(--card);
  border: 1px solid var(--border);
  border-radius: 32px;
  box-shadow: var(--shadow);
  padding: 28px;
  backdrop-filter: blur(10px);
}

.section-header {
  display: grid;
  gap: 10px;
}

.section-title-wrap {
  display: flex;
  align-items: center;
  gap: 12px;
}

.section-title-wrap h3 {
  margin: 0;
  font-size: clamp(1.6rem, 2vw, 2.4rem);
}

.section-summary {
  margin: -4px 0 0;
  color: var(--text-soft);
  line-height: 1.8;
  font-size: 0.98rem;
}

.steps-grid {
  display: grid;
  grid-template-columns: repeat(5, minmax(180px, 1fr));
  gap: 18px;
}

.steps-grid.vertical {
  grid-template-columns: repeat(5, minmax(180px, 1fr));
}

.steps-grid.okx-grid {
  grid-template-columns: repeat(3, minmax(220px, 1fr));
}

.step-card {
  position: relative;
  display: grid;
  gap: 12px;
  padding: 22px 18px 18px;
  border: 1px solid var(--border);
  border-radius: 22px;
  background: var(--card-strong);
  box-shadow: var(--shadow);
}

.step-card.highlight {
  background: linear-gradient(180deg, rgba(45, 109, 246, 0.09), rgba(19, 179, 139, 0.06));
}

.step-index {
  width: 48px;
  height: 48px;
  border-radius: 14px;
  display: grid;
  place-items: center;
  background: linear-gradient(135deg, var(--primary), var(--accent));
  color: white;
  font-weight: 800;
  font-size: 0.82rem;
}

.step-card h4 {
  margin: 0;
  font-size: 1.12rem;
}

.step-card p {
  margin: 0;
  color: var(--text-soft);
  line-height: 1.75;
  font-size: 0.96rem;
}

.step-media {
  overflow: visible;
  border-radius: 16px;
  border: 1px solid var(--border);
  background: rgba(255, 255, 255, 0.28);
  margin-top: 4px;
  padding: 0;
}

.step-media img {
  display: block;
  width: 100%;
  height: auto;
  max-width: 100%;
  object-fit: contain;
  border-radius: 16px;
  transition: transform 0.25s ease;
}

.step-card:hover .step-media img {
  transform: scale(1.01);
}

.info-panel {
  padding: 30px 28px;
}

.segmented-panel {
  padding: 32px 28px;
  border-radius: 32px;
}

.info-header {
  display: flex;
  align-items: center;
  gap: 10px;
  margin-bottom: 18px;
}

.info-header h3 {
  margin: 0;
  font-size: clamp(1.4rem, 2vw, 2rem);
}

.checklist {
  margin: 0;
  padding-left: 20px;
  display: grid;
  gap: 12px;
  color: var(--text-soft);
  line-height: 1.8;
}

.checklist li::marker {
  color: var(--accent);
}

.okx-notes {
  margin-top: 22px;
  padding-top: 18px;
  border-top: 1px solid var(--border);
}

.okx-notes h4 {
  margin: 0 0 12px;
  font-size: 1.08rem;
}

.section-summary a {
  color: var(--primary-strong);
  text-decoration: none;
}

.section-summary a:hover {
  text-decoration: underline;
}

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

  .segmented {
    padding: 22px 18px;
  }

  .page-nav {
    justify-content: flex-start;
  }

  .steps-grid,
  .steps-grid.vertical,
  .steps-grid.okx-grid {
    grid-template-columns: repeat(2, minmax(220px, 1fr));
  }
}

@media (max-width: 640px) {
  .page-shell {
    padding-left: 14px;
    padding-right: 14px;
  }

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

  .hero,
  .info-panel {
    padding: 22px 18px;
  }

  .steps-grid,
  .steps-grid.vertical,
  .steps-grid.okx-grid {
    grid-template-columns: 1fr;
  }

  .section-title-wrap {
    flex-direction: column;
    align-items: flex-start;
  }
}