@import url("https://fonts.googleapis.com/css2?family=Noto+Sans+SC:wght@400;500;700;800&display=swap");

:root {
  --bg-0: #061826;
  --bg-1: #0a2e45;
  --bg-2: #0f5c88;
  --surface: rgba(10, 29, 45, 0.66);
  --surface-strong: rgba(12, 37, 56, 0.9);
  --text: #f2f8ff;
  --text-soft: #c4dae9;
  --line: rgba(203, 233, 255, 0.2);
  --primary: #3bc3ff;
  --primary-strong: #12a6e7;
  --ok: #54d49f;
  --shadow: 0 30px 55px rgba(0, 0, 0, 0.32);
}

* {
  box-sizing: border-box;
}

html,
body {
  margin: 0;
  min-height: 100%;
}

body {
  font-family: "Noto Sans SC", sans-serif;
  color: var(--text);
  background:
    radial-gradient(circle at 5% 10%, rgba(59, 195, 255, 0.25), transparent 35%),
    radial-gradient(circle at 92% 78%, rgba(84, 212, 159, 0.22), transparent 38%),
    linear-gradient(150deg, var(--bg-0) 0%, var(--bg-1) 45%, var(--bg-2) 100%);
}

a {
  color: inherit;
}

.page-shell {
  position: relative;
  z-index: 1;
  width: min(1080px, calc(100% - 32px));
  margin: 0 auto;
  padding: 40px 0 32px;
}

.brand {
  margin: 0;
  font-size: clamp(34px, 6vw, 52px);
  letter-spacing: 2px;
  font-weight: 800;
}

.subtitle {
  margin: 10px 0 0;
  color: var(--text-soft);
  font-size: 16px;
}

.hero {
  padding: 28px;
  text-align: center;
}

.grid {
  display: grid;
  grid-template-columns: repeat(12, minmax(0, 1fr));
  gap: 16px;
  margin-top: 18px;
}

.card {
  grid-column: span 12;
  background: var(--surface);
  border: 1px solid var(--line);
  border-radius: 20px;
  padding: 20px;
  backdrop-filter: blur(8px);
  box-shadow: 0 16px 30px rgba(0, 0, 0, 0.2);
  animation: rise-in 0.5s ease both;
}

.card h2,
.card h3 {
  margin: 0 0 10px;
}

.muted {
  color: var(--text-soft);
  line-height: 1.65;
}

.actions {
  display: flex;
  flex-wrap: wrap;
  gap: 12px;
  margin-top: 14px;
}

.button {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 8px;
  border: 1px solid rgba(255, 255, 255, 0.15);
  border-radius: 999px;
  padding: 11px 18px;
  text-decoration: none;
  font-size: 14px;
  font-weight: 700;
  letter-spacing: 0.2px;
  transition: transform 0.2s ease, box-shadow 0.2s ease, background-color 0.2s ease;
}

.button.primary {
  color: #04263a;
  background: linear-gradient(120deg, var(--primary), #8ce8ff);
  box-shadow: 0 10px 20px rgba(59, 195, 255, 0.35);
  border-color: transparent;
}

.button.secondary {
  color: var(--text);
  background: var(--surface-strong);
}

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

.footer {
  text-align: center;
  margin-top: 18px;
  color: var(--text-soft);
  font-size: 13px;
}

.floating {
  position: fixed;
  inset: 0;
  pointer-events: none;
  overflow: hidden;
  z-index: 0;
}

.orb {
  position: absolute;
  border-radius: 999px;
  filter: blur(2px);
  opacity: 0.5;
  animation: drift 18s linear infinite;
}

.orb.one {
  width: 240px;
  height: 240px;
  left: -40px;
  top: 8%;
  background: rgba(59, 195, 255, 0.22);
}

.orb.two {
  width: 180px;
  height: 180px;
  right: 4%;
  top: 16%;
  background: rgba(84, 212, 159, 0.2);
  animation-duration: 14s;
}

.orb.three {
  width: 280px;
  height: 280px;
  right: -80px;
  bottom: -40px;
  background: rgba(172, 227, 255, 0.2);
  animation-duration: 22s;
}

.tabs {
  margin-top: 16px;
}

.tab-list {
  display: flex;
  flex-wrap: wrap;
  gap: 10px;
}

.tab-button {
  background: rgba(255, 255, 255, 0.08);
  color: var(--text);
  border: 1px solid var(--line);
  border-radius: 999px;
  padding: 10px 14px;
  font-size: 14px;
  font-weight: 700;
  cursor: pointer;
  transition: background-color 0.2s ease, transform 0.2s ease;
}

.tab-button[aria-selected="true"] {
  background: linear-gradient(120deg, rgba(59, 195, 255, 0.95), rgba(140, 232, 255, 0.95));
  color: #05273d;
  border-color: transparent;
}

.tab-button:hover {
  transform: translateY(-1px);
}

.tab-panel {
  display: none;
  margin-top: 14px;
  border: 1px solid var(--line);
  border-radius: 16px;
  background: rgba(5, 24, 39, 0.48);
  padding: 18px;
}

.tab-panel.active {
  display: block;
  animation: rise-in 0.28s ease;
}

.download-list {
  display: grid;
  gap: 10px;
  margin-top: 12px;
}

.download-item {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 12px;
  padding: 12px;
  background: rgba(255, 255, 255, 0.03);
  border: 1px solid rgba(255, 255, 255, 0.08);
  border-radius: 12px;
}

.download-item strong {
  display: block;
}

.download-item span {
  color: var(--text-soft);
  font-size: 12px;
}

.chip {
  display: inline-flex;
  align-items: center;
  border-radius: 999px;
  font-size: 12px;
  padding: 4px 10px;
  border: 1px solid rgba(84, 212, 159, 0.35);
  color: #ccffe8;
  background: rgba(84, 212, 159, 0.15);
}

@media (min-width: 880px) {
  .span-6 {
    grid-column: span 6;
  }

  .span-4 {
    grid-column: span 4;
  }
}

@media (max-width: 640px) {
  .page-shell {
    width: min(1080px, calc(100% - 20px));
    padding-top: 24px;
  }

  .hero,
  .card {
    padding: 16px;
    border-radius: 16px;
  }

  .tab-button {
    padding: 8px 12px;
    font-size: 13px;
  }
}

@keyframes drift {
  0%,
  100% {
    transform: translateY(0);
  }
  50% {
    transform: translateY(-14px);
  }
}

@keyframes rise-in {
  from {
    opacity: 0;
    transform: translateY(10px);
  }
  to {
    opacity: 1;
    transform: translateY(0);
  }
}