:root {
  --telegram: #179cde;
  --text: #222;
  --muted: #67696a;
  --line: #e8e8e8;
}

* {
  box-sizing: border-box;
}

body {
  margin: 0;
  padding-top: 48px;
  color: var(--text);
  font-family: Arial, "Microsoft YaHei", "PingFang SC", sans-serif;
  background: #fff;
}

a {
  color: var(--telegram);
  text-decoration: none;
}

.site-header {
  position: fixed;
  inset: 0 0 auto;
  z-index: 10;
  background: rgba(255, 255, 255, .86);
  border-bottom: 1px solid #ddd;
  backdrop-filter: blur(16px);
}

.top-nav {
  max-width: 1170px;
  height: 48px;
  margin: 0 auto;
  padding: 0 16px;
  display: flex;
  align-items: center;
  justify-content: space-between;
}

.nav-links {
  display: flex;
  height: 48px;
}

.nav-links a,
.twitter-link {
  position: relative;
  display: inline-flex;
  align-items: center;
  min-height: 48px;
  padding: 0 16px;
  font-size: 15px;
  white-space: nowrap;
}

.nav-links a::after,
.twitter-link::after {
  content: "";
  position: absolute;
  left: 4px;
  right: 4px;
  bottom: 0;
  height: 3px;
  background: var(--telegram);
  border-radius: 3px 3px 0 0;
  transform: scaleX(0);
  opacity: 0;
  transition: .18s;
}

.nav-links a:hover::after,
.nav-links a.active::after,
.twitter-link:hover::after {
  transform: scaleX(1);
  opacity: 1;
}

.nav-links a:hover,
.twitter-link:hover {
  text-decoration: none;
}

.twitter-link img {
  width: 21px;
  height: 17px;
  margin-right: 8px;
}

.download-page {
  display: grid;
  place-items: start center;
  min-height: 520px;
  padding: 72px 16px 40px;
  text-align: center;
}

.download-page section {
  width: min(420px, 100%);
}

.desktop-hero {
  padding-top: 58%;
  background: url("images/td_laptop.png") 50% 0 / contain no-repeat;
}

.download-page h1 {
  margin: 0 0 14px;
  color: #383a3b;
  font-size: 26px;
  font-weight: 700;
}

.download-page p {
  margin: 14px 10px 24px;
  color: var(--muted);
  font-size: 17px;
  line-height: 1.55;
}

.button {
  display: inline-block;
  min-width: 266px;
  margin: 10px;
  padding: 10px 14px;
  color: #fff;
  background: #1d98dc;
  border-radius: 5px;
  font-size: 15px;
  font-weight: 700;
  line-height: 2;
}

.button:hover {
  text-decoration: none;
  background: #168bc9;
}

.locked-page a:not(.button) {
  cursor: default;
}

.footer {
  max-width: 925px;
  margin: 10px auto 0;
  padding: 16px;
  border-top: 1px solid var(--line);
}

.footer-grid {
  max-width: 800px;
  margin: 0 auto;
  display: grid;
  grid-template-columns: 210px repeat(4, 1fr);
  gap: 24px;
}

.footer h5 {
  margin: 0 0 9px;
  font-size: 14px;
  font-weight: 700;
}

.footer p,
.footer a {
  display: block;
  margin: 0 0 5px;
  font-size: 13px;
  line-height: 1.6;
}

.mobile-footer {
  display: none;
  justify-content: center;
  gap: 12px;
}

@media (max-width: 640px) {
  .top-nav {
    padding: 0;
    overflow-x: auto;
  }

  .nav-links {
    overflow-x: auto;
  }

  .nav-links a,
  .twitter-link {
    padding: 0 14px;
  }

  .twitter-link {
    display: none;
  }

  .footer-grid {
    display: none;
  }

  .mobile-footer {
    display: flex;
  }
}