:root {
  --field: #f4f8fd;
  --ink: #1b1e26;
  --muted: #5c6673;
  --blue: #3a7bfd;
  --blue-deep: #2d68e0;
  --blue-light: #6799fb;
  --line: #d7e3f4;
  --card: #ffffff;
  --limit: #eef3f8;
  --max: 1120px;
}

* {
  box-sizing: border-box;
}

html {
  scroll-behavior: smooth;
}

body {
  margin: 0;
  background:
    radial-gradient(900px 420px at 78% 8%, rgba(186, 214, 255, 0.45), transparent 70%),
    var(--field);
  color: var(--ink);
  font-family: "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei", "Noto Sans SC", sans-serif;
  font-size: 16px;
  line-height: 1.7;
}

main {
  width: min(var(--max), calc(100% - 48px));
  margin: 0 auto;
}

.hero {
  display: grid;
  grid-template-columns: minmax(0, 1.05fr) minmax(280px, 0.95fr);
  align-items: center;
  gap: 24px;
  padding: 72px 0 24px;
}

.eyebrow {
  display: flex;
  align-items: center;
  gap: 8px;
  margin: 0 0 18px;
  font-size: 32px;
  letter-spacing: 0.08em;
  color: var(--blue-deep);
}

.logo {
  width: 36px;
  height: 36px;
  flex: 0 0 36px;
  object-fit: contain;
}

.eyebrow .en {
  margin-left: 4px;
  letter-spacing: 0.16em;
  font-weight: 600;
}

h1 {
  margin: 0;
  font-size: clamp(40px, 5vw, 64px);
  font-weight: 600;
  letter-spacing: -0.03em;
  line-height: 1.18;
}

.lead {
  max-width: 34em;
  margin: 22px 0 0;
  color: var(--muted);
  font-size: 18px;
}

.hero-art {
  margin: 0;
}

.hero-art img {
  display: block;
  width: 100%;
  height: auto;
  -webkit-mask-image: radial-gradient(ellipse at 68% 54%, #000 42%, transparent 72%);
  mask-image: radial-gradient(ellipse at 68% 54%, #000 42%, transparent 72%);
}

.downloads {
  display: grid;
  grid-template-columns: repeat(5, minmax(0, 1fr));
  gap: 14px;
  padding-bottom: 72px;
}

.dl {
  display: flex;
  flex-direction: column;
  align-items: flex-start;
  min-height: 148px;
  padding: 18px 16px 16px;
  background: var(--card);
  border: 1px solid var(--line);
  border-radius: 12px;
  color: inherit;
  text-decoration: none;
}
.dl.disable{
  pointer-events: none;
  color: #999;
  cursor: not-allowed;
  text-decoration: none;
}

.dl:hover {
  border-color: #b9d0f2;
  box-shadow: 0 10px 28px rgba(58, 123, 253, 0.08);
}

.dl:focus-visible {
  outline: 2px solid var(--ink);
  outline-offset: 3px;
}

.os {
  font-size: 18px;
  font-weight: 600;
}

.for {
  margin-top: 6px;
  color: var(--muted);
  font-size: 13px;
  line-height: 1.45;
}

.go {
  margin-top: auto;
  padding-top: 16px;
  color: var(--blue);
  font-size: 14px;
  font-weight: 600;
}

.dl:hover .go {
  color: var(--blue-deep);
}
.dl.disable .go{
  color: var(--blue-light);
}

.security {
  display: grid;
  grid-template-columns: minmax(0, 0.9fr) minmax(280px, 1.1fr);
  gap: 36px;
  align-items: center;
  margin: 0 calc(50% - 50vw);
  padding: 72px max(24px, calc(50vw - var(--max) / 2));
  background: linear-gradient(180deg, #e8f1fc 0%, #f4f8fd 100%);
}

.security h2,
.features h2 {
  margin: 0 0 16px;
  font-size: 32px;
  font-weight: 600;
  letter-spacing: -0.02em;
  line-height: 1.25;
}

.security p {
  margin: 0 0 14px;
  color: var(--muted);
}

.keyline {
  margin-top: 22px !important;
  color: var(--ink) !important;
  font-size: 14px;
}

.keyline code {
  margin-left: 8px;
  padding: 2px 8px;
  background: rgba(255, 255, 255, 0.72);
  border-radius: 6px;
  font-family: "Cascadia Mono", Consolas, "Sarasa Mono SC", monospace;
  font-size: 15px;
  letter-spacing: 0.14em;
}

.flow {
  display: block;
  width: 100%;
  height: auto;
}

.node rect {
  fill: #ffffff;
  stroke: #c5d7f0;
}

.node .core {
  fill: #d7e7ff;
  stroke: #3a7bfd;
}

.node text {
  fill: #1b1e26;
  font-size: 14px;
  text-anchor: middle;
}

.node.server {
  opacity: 0.55;
}

.node.server rect {
  fill: #f7f9fc;
  stroke: #b7c4d4;
}

.node.server .core,
.node.server rect:last-of-type {
  fill: none;
  stroke: #9aabbe;
}

.relay {
  margin: 0;
  text-align: center;
  color: #7d8b9c;
  font-size: 13px;
}

.features {
  padding: 88px 0 40px;
}

.grid {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 16px;
}

.card {
  margin: 0;
  padding: 28px 26px 24px;
  background: var(--card);
  border: 1px solid var(--line);
  border-radius: 16px;
}

.card h3 {
  margin: 0 0 10px;
  font-size: 20px;
  font-weight: 600;
}

.card p {
  margin: 0;
  color: var(--muted);
}

.card.limit {
  background: var(--limit);
}

footer {
  width: min(var(--max), calc(100% - 48px));
  margin: 0 auto;
  padding: 28px 0 48px;
  color: #8a94a1;
  font-size: 13px;
  text-align: center;
}

footer p {
  margin: 0;
}
.reverse {
    unicode-bidi: bidi-override;
    direction: rtl;
}	


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

  .hero {
    min-height: 0;
    padding-top: 48px;
  }

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

  .downloads .dl:last-child {
    grid-column: 1 / -1;
  }
}

@media (max-width: 720px) {
  main,
  footer {
    width: min(var(--max), calc(100% - 32px));
  }

  .hero,
  .security,
  .grid,
  .downloads {
    grid-template-columns: 1fr;
  }

  .downloads .dl:last-child {
    grid-column: auto;
  }

  .hero {
    padding-top: 36px;
  }

  .security {
    padding-top: 48px;
    padding-bottom: 48px;
  }

  .features {
    padding-top: 56px;
  }
}

@media (prefers-reduced-motion: reduce) {
  html {
    scroll-behavior: auto;
  }

  .packet {
    display: none;
  }
}