/* Premium dark-first · light mode supported */
:root {
  --bg: #fafafa;
  --bg-mesh-1: rgba(99, 102, 241, 0.07);
  --bg-mesh-2: rgba(14, 165, 233, 0.06);
  --bg-mesh-3: rgba(139, 92, 246, 0.05);
  --bg-dot: rgba(99, 102, 241, 0.07);
  --surface: rgba(255, 255, 255, 0.78);
  --surface-strong: #ffffff;
  --text: #0a0a0b;
  --text-muted: #52525b;
  --border: rgba(0, 0, 0, 0.06);
  --accent: #6366f1;
  --accent-2: #0ea5e9;
  --accent-soft: rgba(99, 102, 241, 0.1);
  --glow: rgba(99, 102, 241, 0.18);
  --success: #10b981;
  --warning: #f59e0b;
  --shadow: 0 32px 80px rgba(15, 23, 42, 0.07);
  --radius: 18px;
  --font-display: "Geist", "SF Pro Display", system-ui, sans-serif;
}

html[data-theme="dark"] {
  --bg: #030712;
  --bg-mesh-1: rgba(99, 102, 241, 0.14);
  --bg-mesh-2: rgba(56, 189, 248, 0.1);
  --bg-mesh-3: rgba(167, 139, 250, 0.08);
  --bg-dot: rgba(129, 140, 248, 0.12);
  --surface: rgba(15, 23, 42, 0.55);
  --surface-strong: rgba(15, 23, 42, 0.82);
  --text: #f8fafc;
  --text-muted: #94a3b8;
  --border: rgba(148, 163, 184, 0.1);
  --accent: #818cf8;
  --accent-2: #38bdf8;
  --accent-soft: rgba(129, 140, 248, 0.12);
  --glow: rgba(129, 140, 248, 0.22);
  --shadow: 0 40px 100px rgba(0, 0, 0, 0.55);
}

@media (prefers-color-scheme: dark) {
  html:not([data-theme="light"]) {
    --bg: #030712;
    --bg-mesh-1: rgba(99, 102, 241, 0.14);
    --bg-mesh-2: rgba(56, 189, 248, 0.1);
    --bg-mesh-3: rgba(167, 139, 250, 0.08);
    --bg-dot: rgba(129, 140, 248, 0.12);
    --surface: rgba(15, 23, 42, 0.55);
    --surface-strong: rgba(15, 23, 42, 0.82);
    --text: #f8fafc;
    --text-muted: #94a3b8;
    --border: rgba(148, 163, 184, 0.1);
    --accent: #818cf8;
    --accent-2: #38bdf8;
    --accent-soft: rgba(129, 140, 248, 0.12);
    --glow: rgba(129, 140, 248, 0.22);
    --shadow: 0 40px 100px rgba(0, 0, 0, 0.55);
  }
}

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

html {
  scroll-behavior: smooth;
}

body {
  margin: 0;
  min-height: 100dvh;
  font-family: var(--font-display);
  background: var(--bg);
  color: var(--text);
  overflow-x: hidden;
  -webkit-font-smoothing: antialiased;
}

.bg-mesh {
  position: fixed;
  inset: 0;
  pointer-events: none;
  z-index: 0;
  overflow: hidden;
  background-color: var(--bg);
  background-image:
    radial-gradient(ellipse 85% 55% at 8% -8%, var(--bg-mesh-1), transparent 52%),
    radial-gradient(ellipse 65% 45% at 92% 0%, var(--bg-mesh-2), transparent 48%),
    radial-gradient(ellipse 55% 40% at 78% 88%, var(--bg-mesh-3), transparent 50%),
    radial-gradient(ellipse 50% 35% at 18% 92%, var(--bg-mesh-2), transparent 45%);
}

.bg-mesh::before {
  content: "";
  position: absolute;
  inset: 0;
  background-image: radial-gradient(circle at 1px 1px, var(--bg-dot) 1px, transparent 0);
  background-size: 28px 28px;
  opacity: 0.55;
  mask-image: radial-gradient(ellipse 90% 80% at 50% 35%, black 15%, transparent 72%);
}

.bg-mesh::after {
  content: "";
  position: absolute;
  inset: 0;
  background: radial-gradient(ellipse 75% 65% at 50% 42%, transparent 35%, var(--bg) 100%);
  opacity: 0.85;
}

.page {
  position: relative;
  z-index: 1;
  max-width: 960px;
  margin: 0 auto;
  padding: 28px 24px 56px;
}

.topbar {
  display: flex;
  align-items: center;
  justify-content: space-between;
  margin-bottom: 56px;
}

.brand {
  display: flex;
  align-items: center;
  gap: 14px;
  font-weight: 600;
  font-size: 15px;
  letter-spacing: -0.03em;
}

.brand-mark {
  width: 42px;
  height: 42px;
  border-radius: 13px;
  background: linear-gradient(145deg, var(--accent) 0%, var(--accent-2) 100%);
  display: grid;
  place-items: center;
  box-shadow: 0 10px 30px var(--glow);
}

.brand-mark svg {
  width: 22px;
  height: 22px;
  color: white;
}

.icon-btn {
  width: 42px;
  height: 42px;
  border: 1px solid var(--border);
  border-radius: 13px;
  background: var(--surface);
  backdrop-filter: blur(16px);
  color: var(--text-muted);
  cursor: pointer;
  display: grid;
  place-items: center;
  transition: all 0.25s ease;
}

.icon-btn:hover {
  border-color: color-mix(in srgb, var(--accent) 40%, transparent);
  color: var(--accent);
  transform: translateY(-1px);
}

.hero {
  text-align: center;
  margin-bottom: 40px;
}

.eyebrow {
  display: inline-flex;
  align-items: center;
  gap: 10px;
  padding: 7px 16px 7px 12px;
  border-radius: 999px;
  border: 1px solid var(--border);
  background: var(--surface);
  backdrop-filter: blur(16px);
  font-size: 12px;
  font-weight: 500;
  color: var(--text-muted);
  margin-bottom: 24px;
  letter-spacing: 0.02em;
}

.pulse-dot {
  width: 7px;
  height: 7px;
  border-radius: 50%;
  background: var(--success);
  box-shadow: 0 0 12px var(--success);
  animation: pulse 2.4s ease-in-out infinite;
}

@keyframes pulse {
  0%,
  100% {
    opacity: 1;
    transform: scale(1);
  }
  50% {
    opacity: 0.55;
    transform: scale(0.92);
  }
}

.hero h1 {
  margin: 0 0 20px;
  font-size: clamp(2rem, 5.8vw, 3.25rem);
  font-weight: 700;
  line-height: 1.12;
  letter-spacing: -0.04em;
}

.hero h1 .gradient {
  display: inline;
  background: linear-gradient(115deg, var(--accent) 0%, var(--accent-2) 55%, color-mix(in srgb, var(--accent-2) 70%, #fff) 100%);
  -webkit-background-clip: text;
  background-clip: text;
  color: transparent;
  filter: drop-shadow(0 0 40px var(--glow));
}

.hero-lead {
  margin: 0 auto 12px;
  max-width: 540px;
  color: var(--text);
  font-size: 1.125rem;
  line-height: 1.6;
  font-weight: 500;
  letter-spacing: -0.01em;
}

.hero-lead strong {
  color: var(--accent);
  font-weight: 650;
}

.hero-sub {
  margin: 0 auto;
  max-width: 480px;
  color: var(--text-muted);
  font-size: 0.9375rem;
  line-height: 1.65;
  font-weight: 400;
}

.download-card {
  border: 1px solid var(--border);
  border-radius: calc(var(--radius) + 6px);
  background: var(--surface-strong);
  backdrop-filter: blur(24px) saturate(1.2);
  box-shadow: var(--shadow);
  padding: 28px;
  position: relative;
  overflow: hidden;
}

.download-card::after {
  content: "";
  position: absolute;
  inset: 0;
  border-radius: inherit;
  padding: 1px;
  background: linear-gradient(
    160deg,
    color-mix(in srgb, var(--accent) 35%, transparent),
    transparent 40%,
    color-mix(in srgb, var(--accent-2) 25%, transparent)
  );
  -webkit-mask:
    linear-gradient(#fff 0 0) content-box,
    linear-gradient(#fff 0 0);
  mask:
    linear-gradient(#fff 0 0) content-box,
    linear-gradient(#fff 0 0);
  -webkit-mask-composite: xor;
  mask-composite: exclude;
  pointer-events: none;
  opacity: 0.65;
}

.card-head {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  justify-content: space-between;
  gap: 12px;
  margin-bottom: 18px;
}

.card-head h2 {
  margin: 0;
  font-size: 1rem;
  font-weight: 600;
  letter-spacing: -0.02em;
}

.mirror-badge {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  padding: 6px 13px;
  border-radius: 999px;
  font-size: 11px;
  font-weight: 600;
  letter-spacing: 0.04em;
  text-transform: uppercase;
  border: 1px solid var(--border);
  background: var(--accent-soft);
  color: var(--text-muted);
}

.mirror-badge[data-state="probing"] .badge-icon {
  animation: spin 0.9s linear infinite;
}

.mirror-badge[data-state="github"] {
  color: var(--accent-2);
}

.mirror-badge[data-state="gitee"] {
  color: var(--warning);
}

@keyframes spin {
  to {
    transform: rotate(360deg);
  }
}

.detect-hint {
  margin: 0 0 18px;
  font-size: 13px;
  color: var(--text-muted);
}

.platform-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 10px;
  margin-bottom: 22px;
}

.platform-option {
  position: relative;
  border: 1px solid var(--border);
  border-radius: 16px;
  padding: 16px 14px;
  background: var(--surface);
  color: var(--text);
  cursor: pointer;
  text-align: left;
  transition: all 0.28s cubic-bezier(0.22, 1, 0.36, 1);
}

.platform-option:hover {
  transform: translateY(-2px);
  border-color: color-mix(in srgb, var(--accent) 35%, transparent);
}

.platform-option[aria-checked="true"] {
  border-color: color-mix(in srgb, var(--accent) 55%, transparent);
  background: var(--accent-soft);
  box-shadow: 0 0 0 1px color-mix(in srgb, var(--accent) 30%, transparent);
}

.platform-option[aria-checked="true"]::after {
  content: "";
  position: absolute;
  top: 12px;
  right: 12px;
  width: 18px;
  height: 18px;
  border-radius: 50%;
  background: linear-gradient(145deg, var(--accent), var(--accent-2));
  box-shadow: 0 4px 12px var(--glow);
  background-image: url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' viewBox='0 0 24 24' fill='none' stroke='white' stroke-width='3'%3E%3Cpath d='M5 12l5 5L20 7'/%3E%3C/svg%3E");
  background-size: 11px;
  background-repeat: no-repeat;
  background-position: center;
}

.platform-icon {
  display: flex;
  align-items: center;
  justify-content: center;
  width: 36px;
  height: 36px;
  margin-bottom: 12px;
  border-radius: 10px;
  background: var(--accent-soft);
  color: var(--accent);
}

.platform-icon svg {
  width: 20px;
  height: 20px;
}

.platform-label {
  display: block;
  font-size: 14px;
  font-weight: 600;
  margin-bottom: 3px;
  letter-spacing: -0.02em;
}

.platform-sub {
  display: block;
  font-size: 11px;
  color: var(--text-muted);
  line-height: 1.4;
}

.mirror-toggle {
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
  margin-bottom: 10px;
}

.mirror-hint {
  margin: 0 0 18px;
  font-size: 12px;
  line-height: 1.5;
  color: var(--text-muted);
  display: none;
}

.mirror-hint[data-visible="true"] {
  display: block;
}

.mirror-chip {
  border: 1px solid var(--border);
  border-radius: 999px;
  padding: 8px 16px;
  font-size: 12px;
  font-weight: 500;
  background: transparent;
  color: var(--text-muted);
  cursor: pointer;
  transition: all 0.22s ease;
}

.mirror-chip[aria-pressed="true"] {
  color: var(--text);
  border-color: color-mix(in srgb, var(--accent) 45%, transparent);
  background: var(--accent-soft);
}

.download-row {
  display: flex;
  flex-wrap: wrap;
  gap: 10px;
}

.btn-download {
  flex: 1 1 240px;
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 10px;
  min-height: 54px;
  padding: 0 28px;
  border: none;
  border-radius: 15px;
  font-size: 15px;
  font-weight: 600;
  letter-spacing: -0.01em;
  color: white;
  cursor: pointer;
  text-decoration: none;
  background: linear-gradient(145deg, var(--accent) 0%, color-mix(in srgb, var(--accent-2) 80%, var(--accent)) 100%);
  box-shadow: 0 14px 40px var(--glow);
  position: relative;
  overflow: hidden;
  transition: transform 0.22s ease, box-shadow 0.22s ease;
}

.btn-download:hover {
  transform: translateY(-2px);
  box-shadow: 0 18px 48px var(--glow);
}

.btn-download::before {
  content: "";
  position: absolute;
  inset: 0;
  background: linear-gradient(105deg, transparent 35%, rgba(255, 255, 255, 0.18) 50%, transparent 65%);
  transform: translateX(-130%);
  transition: transform 0.65s ease;
}

.btn-download:hover::before {
  transform: translateX(130%);
}

.btn-secondary {
  min-height: 54px;
  padding: 0 20px;
  border-radius: 15px;
  border: 1px solid var(--border);
  background: var(--surface);
  color: var(--text-muted);
  font-size: 14px;
  font-weight: 500;
  cursor: pointer;
  transition: all 0.22s ease;
}

.btn-secondary:hover {
  border-color: color-mix(in srgb, var(--accent) 40%, transparent);
  color: var(--accent);
}

.meta-line {
  margin-top: 16px;
  font-size: 12px;
  color: var(--text-muted);
  line-height: 1.55;
}

.features {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 12px;
  margin-top: 32px;
}

.feature {
  padding: 20px;
  border-radius: 16px;
  border: 1px solid var(--border);
  background: var(--surface);
  backdrop-filter: blur(12px);
  transition: border-color 0.25s ease;
}

.feature:hover {
  border-color: color-mix(in srgb, var(--accent) 25%, transparent);
}

.feature-num {
  display: block;
  font-size: 11px;
  font-weight: 600;
  letter-spacing: 0.08em;
  color: var(--accent);
  margin-bottom: 10px;
}

.feature strong {
  display: block;
  font-size: 14px;
  font-weight: 600;
  margin-bottom: 8px;
  letter-spacing: -0.02em;
}

.feature span {
  font-size: 13px;
  color: var(--text-muted);
  line-height: 1.55;
}

.mobile-notice {
  display: none;
  margin-top: 16px;
  padding: 14px 16px;
  border-radius: 14px;
  border: 1px dashed var(--border);
  background: var(--accent-soft);
  color: var(--text-muted);
  font-size: 13px;
  line-height: 1.55;
}

.mobile-notice[data-visible="true"] {
  display: block;
}

footer {
  margin-top: 48px;
  text-align: center;
  font-size: 12px;
  color: var(--text-muted);
}

footer a {
  color: var(--accent);
  text-decoration: none;
  font-weight: 500;
}

footer a:hover {
  text-decoration: underline;
}

@media (max-width: 720px) {
  .page {
    padding: 20px 16px 40px;
  }

  .topbar {
    margin-bottom: 36px;
  }

  .platform-grid,
  .features {
    grid-template-columns: 1fr;
  }

  .download-row {
    flex-direction: column;
  }

  .btn-download,
  .btn-secondary {
    width: 100%;
  }
}

@media (max-width: 480px) {
  .mirror-toggle {
    flex-direction: column;
  }

  .mirror-chip {
    width: 100%;
    text-align: center;
  }
}