:root {
  --bg: #181a20;
  --bg-deep: #0b0e11;
  --surface: #1e2329;
  --surface-2: #2b3139;
  --accent: #f0b90b;
  --accent-hover: #fcd535;
  --accent-ink: #0b0e11;
  --text: #eaecef;
  --text-muted: #848e9c;
  --text-dim: #707a8a;
  --header-h: 64px;
  --radius: 12px;
  --font: 'BinancePlex', 'IBM Plex Sans', 'PingFang SC', 'Microsoft YaHei', system-ui, sans-serif;
}

*,
*::before,
*::after {
  box-sizing: border-box;
}

html {
  scroll-behavior: smooth;
}

body {
  margin: 0;
  font-family: var(--font);
  background: var(--bg);
  color: var(--text);
  line-height: 1.5;
  -webkit-font-smoothing: antialiased;
}

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

button {
  font: inherit;
  color: inherit;
  background: none;
  border: 0;
  cursor: pointer;
  padding: 0;
}

img {
  max-width: 100%;
  height: auto;
  display: block;
}

.skip-link {
  position: absolute;
  left: -999px;
  top: 0;
  z-index: 999;
  padding: 8px 12px;
  background: var(--accent);
  color: var(--accent-ink);
}

.skip-link:focus {
  left: 8px;
}

.sr-only {
  position: absolute;
  width: 1px;
  height: 1px;
  padding: 0;
  margin: -1px;
  overflow: hidden;
  clip: rect(0, 0, 0, 0);
  border: 0;
}

/* Header */
.site-header {
  position: sticky;
  top: 0;
  z-index: 100;
  height: var(--header-h);
  background: rgba(24, 26, 32, 0.85);
  backdrop-filter: blur(16px);
  border-bottom: 1px solid transparent;
  transition: background 0.2s ease, border-color 0.2s ease;
}

.site-header.is-scrolled {
  background: rgba(11, 14, 17, 0.94);
  border-bottom-color: rgba(255, 255, 255, 0.06);
}

.header-inner {
  max-width: 1200px;
  height: 100%;
  margin: 0 auto;
  padding: 0 24px;
  display: flex;
  align-items: center;
  gap: 16px;
}

.brand {
  display: inline-flex;
  align-items: center;
  gap: 10px;
  flex-shrink: 0;
}

.brand-text {
  font-size: 20px;
  font-weight: 700;
  letter-spacing: 0.01em;
}

.header-actions {
  display: flex;
  align-items: center;
  margin-left: auto;
}

.icon-btn {
  width: 40px;
  height: 40px;
  display: inline-flex;
  align-items: center;
  justify-content: center;
  border-radius: 8px;
  color: var(--text);
  transition: background 0.15s ease;
}

.icon-btn:hover,
.icon-btn[aria-expanded='true'] {
  background: rgba(255, 255, 255, 0.06);
}

/* Language panel */
.lang-overlay {
  position: fixed;
  inset: 0;
  z-index: 200;
  background: rgba(0, 0, 0, 0.55);
}

.lang-panel {
  position: fixed;
  top: calc(var(--header-h) + 8px);
  right: 16px;
  z-index: 210;
  width: min(420px, calc(100vw - 24px));
  max-height: min(560px, calc(100vh - var(--header-h) - 32px));
  display: flex;
  flex-direction: column;
  background: var(--surface);
  border: 1px solid rgba(255, 255, 255, 0.08);
  border-radius: 16px;
  box-shadow: 0 16px 48px rgba(0, 0, 0, 0.45);
  overflow: hidden;
}

.lang-panel[hidden],
.lang-overlay[hidden] {
  display: none !important;
}

.lang-panel-header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 16px 16px 8px;
}

.lang-panel-title {
  margin: 0;
  font-size: 16px;
  font-weight: 600;
}

.lang-panel-close {
  width: 36px;
  height: 36px;
  display: inline-flex;
  align-items: center;
  justify-content: center;
  border-radius: 8px;
}

.lang-panel-close:hover {
  background: rgba(255, 255, 255, 0.06);
}

.lang-search-wrap {
  position: relative;
  margin: 0 16px 12px;
}

.lang-search-icon {
  position: absolute;
  left: 12px;
  top: 50%;
  transform: translateY(-50%);
  color: var(--text-muted);
  pointer-events: none;
}

.lang-search {
  width: 100%;
  height: 40px;
  padding: 0 12px 0 36px;
  border: 1px solid rgba(255, 255, 255, 0.12);
  border-radius: 8px;
  background: rgba(255, 255, 255, 0.04);
  color: var(--text);
  font-size: 14px;
  outline: none;
}

.lang-search:focus {
  border-color: var(--accent);
}

.lang-list {
  flex: 1;
  overflow-y: auto;
  padding: 0 8px 12px;
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 4px;
}

.lang-option {
  display: block;
  width: 100%;
  text-align: left;
  padding: 10px 12px;
  border-radius: 8px;
  font-size: 14px;
  transition: background 0.15s ease;
}

.lang-option:hover {
  background: rgba(255, 255, 255, 0.06);
}

.lang-option.is-active {
  background: rgba(240, 185, 11, 0.16);
  color: var(--accent);
  font-weight: 600;
}

.lang-empty {
  grid-column: 1 / -1;
  margin: 12px;
  color: var(--text-muted);
  font-size: 13px;
  text-align: center;
}

html[dir='rtl'] .lang-panel {
  right: auto;
  left: 16px;
}

html[dir='rtl'] .lang-search {
  padding: 0 36px 0 12px;
}

html[dir='rtl'] .lang-search-icon {
  left: auto;
  right: 12px;
}

html[dir='rtl'] .lang-option {
  text-align: right;
}

/* Hero */
.hero {
  position: relative;
  min-height: calc(100vh - var(--header-h));
  min-height: 640px;
  background:
    radial-gradient(ellipse at 20% 0%, rgba(240, 185, 11, 0.18), transparent 50%),
    radial-gradient(ellipse at 90% 30%, rgba(240, 185, 11, 0.08), transparent 45%),
    linear-gradient(180deg, #181a20 0%, #0b0e11 100%);
  overflow: hidden;
}

.hero-inner {
  max-width: 1200px;
  margin: 0 auto;
  padding: 72px 24px 64px;
  display: grid;
  grid-template-columns: 1.15fr 0.85fr;
  gap: 48px;
  align-items: center;
}

.hero-eyebrow {
  margin: 0 0 12px;
  color: var(--accent);
  font-size: 14px;
  font-weight: 600;
  letter-spacing: 0.04em;
}

.hero-title {
  margin: 0 0 16px;
  font-size: clamp(36px, 5vw, 56px);
  font-weight: 700;
  line-height: 1.15;
  letter-spacing: -0.02em;
}

.hero-count {
  display: block;
  color: var(--accent);
}

.hero-desc {
  margin: 0 0 28px;
  max-width: 34em;
  color: var(--text-muted);
  font-size: 16px;
}

.download-buttons {
  display: flex;
  flex-wrap: wrap;
  gap: 12px;
  margin-bottom: 12px;
}

.download-btn {
  display: inline-flex;
  align-items: center;
  gap: 10px;
  min-height: 48px;
  padding: 0 22px;
  border-radius: 10px;
  background: var(--accent);
  color: var(--accent-ink);
  font-size: 16px;
  font-weight: 700;
  transition: background 0.15s ease, transform 0.15s ease;
}

.download-btn:hover {
  background: var(--accent-hover);
}

.ios-hint {
  margin: 0 0 28px;
  color: var(--text-dim);
  font-size: 13px;
}

.trust-row {
  display: flex;
  flex-wrap: wrap;
  gap: 28px;
}

.trust-item {
  display: flex;
  flex-direction: column;
  gap: 4px;
}

.trust-item strong {
  font-size: 22px;
  font-weight: 700;
  color: #fff;
}

.trust-item span {
  font-size: 13px;
  color: var(--text-muted);
}

.qr-card {
  justify-self: end;
  width: min(340px, 100%);
  padding: 28px 24px;
  border-radius: 24px;
  background: var(--surface);
  border: 1px solid rgba(255, 255, 255, 0.06);
  text-align: center;
}

.qr-title {
  margin: 0 0 6px;
  font-size: 18px;
  font-weight: 700;
}

.qr-subtitle {
  margin: 0 0 16px;
  color: var(--text-muted);
  font-size: 13px;
}

.qr-box {
  width: 160px;
  height: 160px;
  margin: 0 auto 12px;
  padding: 8px;
  background: #fff;
  border-radius: 12px;
}

.qr-box img {
  width: 100% !important;
  height: 100% !important;
}

.qr-alt {
  margin: 0 0 20px;
  color: var(--text-dim);
  font-size: 12px;
}

.phone-preview {
  display: flex;
  justify-content: center;
}

.phone-preview img {
  width: 160px;
  height: auto;
  margin: 0 auto;
  filter: drop-shadow(0 12px 28px rgba(0, 0, 0, 0.35));
}

/* Features */
.features {
  padding: 72px 0;
  background: var(--bg-deep);
}

.section-inner {
  max-width: 1200px;
  margin: 0 auto;
  padding: 0 24px;
}

.features h2,
.faq h2 {
  margin: 0 0 32px;
  font-size: clamp(28px, 3.5vw, 36px);
  font-weight: 700;
}

.feature-grid {
  display: grid;
  grid-template-columns: repeat(3, minmax(0, 1fr));
  gap: 20px;
}

.feature-card {
  padding: 28px 24px;
  border-radius: 16px;
  background: var(--surface);
  border: 1px solid rgba(255, 255, 255, 0.05);
}

.feature-icon {
  width: 36px;
  height: 36px;
  margin-bottom: 16px;
  display: inline-flex;
  align-items: center;
  justify-content: center;
  border-radius: 50%;
  background: rgba(240, 185, 11, 0.15);
  color: var(--accent);
  font-size: 14px;
  font-weight: 700;
}

.feature-card h3 {
  margin: 0 0 10px;
  font-size: 18px;
}

.feature-card p {
  margin: 0;
  color: var(--text-muted);
  font-size: 14px;
  line-height: 1.6;
}

/* FAQ */
.faq {
  padding: 72px 0 96px;
  background: var(--bg);
}

.faq-inner {
  max-width: 800px;
}

.faq-item {
  border-bottom: 1px solid rgba(255, 255, 255, 0.08);
}

.faq-trigger {
  width: 100%;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 16px;
  padding: 20px 0;
  text-align: left;
  font-size: 16px;
  font-weight: 600;
}

.faq-chevron {
  flex-shrink: 0;
  color: var(--text-muted);
  transition: transform 0.2s ease;
}

.faq-item.open .faq-chevron {
  transform: rotate(180deg);
}

.faq-panel {
  display: none;
  padding: 0 0 20px;
}

.faq-item.open .faq-panel {
  display: block;
}

.faq-panel p {
  margin: 0;
  color: var(--text-muted);
  font-size: 14px;
  line-height: 1.7;
}

/* Footer */
.site-footer {
  padding: 56px 0 40px;
  background: var(--bg-deep);
  border-top: 1px solid rgba(255, 255, 255, 0.06);
}

.footer-inner {
  max-width: 1200px;
  margin: 0 auto;
  padding: 0 24px;
}

.footer-top {
  display: grid;
  grid-template-columns: 220px 1fr;
  gap: 40px;
}

.footer-brand {
  display: inline-flex;
  align-items: center;
  gap: 10px;
  font-size: 22px;
  font-weight: 700;
  margin-bottom: 12px;
}

.footer-copy {
  margin: 0 0 20px;
  color: var(--text-dim);
  font-size: 13px;
}

.lang-btn {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  padding: 10px 14px;
  border: 1px solid rgba(255, 255, 255, 0.2);
  border-radius: 8px;
  font-size: 13px;
}

.lang-btn:hover {
  border-color: var(--accent);
  color: var(--accent);
}

.footer-cols {
  display: grid;
  grid-template-columns: repeat(4, minmax(0, 1fr));
  gap: 24px 16px;
}

.footer-col {
  display: flex;
  flex-direction: column;
  gap: 12px;
}

.footer-col h3 {
  margin: 0 0 4px;
  font-size: 14px;
  font-weight: 700;
}

.footer-col a {
  color: var(--text-muted);
  font-size: 13px;
}

.footer-col a:hover {
  color: var(--accent);
}

.footer-bottom {
  margin-top: 48px;
  padding-top: 28px;
  border-top: 1px solid rgba(255, 255, 255, 0.08);
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 24px;
  flex-wrap: wrap;
}

.social-label {
  margin: 0 0 10px;
  font-size: 14px;
  font-weight: 600;
}

.social-links {
  display: flex;
  flex-wrap: wrap;
  gap: 16px;
}

.social-links a {
  color: var(--text-muted);
  font-size: 13px;
}

.social-links a:hover {
  color: var(--accent);
}

.footer-note {
  margin: 0;
  color: var(--text-dim);
  font-size: 13px;
}

/* Responsive */
@media (max-width: 960px) {
  .hero {
    min-height: auto;
    background:
      radial-gradient(ellipse at 30% 0%, rgba(240, 185, 11, 0.2), transparent 55%),
      linear-gradient(180deg, #181a20 0%, #0b0e11 80%);
  }

  .hero-inner {
    grid-template-columns: 1fr;
    padding-top: 48px;
    padding-bottom: 40px;
  }

  .qr-card {
    display: none !important;
  }

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

  .footer-top {
    grid-template-columns: 1fr;
  }

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

  .lang-panel {
    top: auto;
    bottom: 0;
    right: 0;
    left: 0;
    width: 100%;
    max-height: min(70vh, 560px);
    border-radius: 16px 16px 0 0;
  }

  .lang-list {
    grid-template-columns: 1fr;
  }
}

@media (max-width: 640px) {
  .header-inner,
  .hero-inner,
  .section-inner,
  .footer-inner {
    padding-left: 16px;
    padding-right: 16px;
  }

  .trust-row {
    gap: 20px;
  }

  .footer-cols {
    grid-template-columns: 1fr 1fr;
  }
}