:root {
  --bg: #f7faff;
  --text: #0f172a;
  --muted: #475569;
  --card: #ffffff;
  --brand: #1f6feb;
  --border: #dbe5f1;
  --header-bg: rgba(247, 250, 255, 0.92);
  --btn-bg: #ffffff;
}

html[data-theme="dark"] {
  --bg: #0b1220;
  --text: #e6edf8;
  --muted: #9fb0ca;
  --card: #111c2f;
  --brand: #3f8cff;
  --border: #25344d;
  --header-bg: rgba(11, 18, 32, 0.9);
  --btn-bg: #15243d;
}

* { box-sizing: border-box; }
body {
  margin: 0;
  font-family: "Segoe UI", Tahoma, Arial, sans-serif;
  color: var(--text);
  background: var(--bg);
  min-height: 100vh;
  display: flex;
  flex-direction: column;
  padding-bottom: 88px;
}

.site-bg::before {
  content: "";
  position: fixed;
  inset: 0;
  background: url("assets/nexora-logo.svg") center center / 40vmin no-repeat;
  opacity: 0.06;
  pointer-events: none;
}

header {
  display: flex;
  justify-content: space-between;
  align-items: center;
  padding: 18px 28px;
  position: sticky;
  top: 0;
  background: var(--header-bg);
  backdrop-filter: blur(6px);
  border-bottom: 1px solid var(--border);
}

.toggle-btn {
  border: 1px solid var(--border);
  background: var(--btn-bg);
  color: var(--text);
  padding: 8px 10px;
  border-radius: 10px;
  cursor: pointer;
  font-weight: 600;
}

header img { height: 40px; }
nav a {
  margin-inline-end: 18px;
  color: var(--text);
  text-decoration: none;
  font-weight: 600;
}

nav a:last-child { margin-inline-end: 0; }

main {
  min-height: calc(100vh - 86px);
  display: grid;
  place-items: center;
  padding: 24px;
  flex: 1;
}

.hero {
  width: min(900px, 100%);
  text-align: center;
}

.hero h1 {
  margin: 0 0 12px;
  font-size: clamp(1.8rem, 4vw, 3rem);
}

.hero p {
  margin: 0 auto 26px;
  color: var(--muted);
  max-width: 700px;
  line-height: 1.7;
}

.download-grid {
  display: grid;
  grid-template-columns: repeat(2, minmax(220px, 1fr));
  gap: 16px;
  width: min(640px, 100%);
  margin: 0 auto;
}

.download-card {
  background: var(--card);
  border: 1px solid var(--border);
  border-radius: 16px;
  padding: 20px;
  text-align: center;
  box-shadow: 0 10px 24px rgba(15, 23, 42, 0.06);
}

.platform-logo {
  width: 42px;
  height: 42px;
  margin-bottom: 8px;
}

.download-card h3 { margin: 0 0 8px; }
.download-card a {
  display: inline-block;
  margin-top: 10px;
  padding: 10px 14px;
  border-radius: 10px;
  background: var(--brand);
  color: white;
  text-decoration: none;
  font-weight: 600;
}

.page {
  width: min(900px, 100%);
  background: var(--card);
  border: 1px solid var(--border);
  border-radius: 16px;
  padding: 24px;
  line-height: 1.8;
  box-shadow: 0 10px 24px rgba(15, 23, 42, 0.05);
}

.site-footer {
  position: fixed;
  left: 0;
  right: 0;
  bottom: 0;
  z-index: 30;
  display: flex;
  justify-content: center;
  align-items: center;
  flex-direction: column;
  gap: 8px;
  padding: 14px 24px;
  border-top: 1px solid var(--border);
  background: var(--header-bg);
  color: var(--muted);
  text-align: center;
}

.copyright-link {
  color: var(--muted);
  text-decoration: none;
  font-weight: 600;
}

.copyright-link:hover {
  text-decoration: underline;
}

.footer-controls {
  display: flex;
  align-items: center;
  gap: 8px;
}

@media (max-width: 700px) {
  .download-grid { grid-template-columns: 1fr; }
  nav a { margin-inline-end: 10px; }
}