:root {
  --bg: #05070c;
  --bg-elevated: #0c121c;
  --steel: #2c4c70;
  --steel-light: #4a6f96;
  --silver: #c5ced8;
  --text: #e8eef5;
  --text-muted: #8a97a8;
  --accent: #3d7ab8;
  --danger-soft: #9bb4cc;
  --radius: 14px;
  --max: 440px;
  --font-display: "Orbitron", "Noto Sans SC", sans-serif;
  --font-body: "Noto Sans SC", system-ui, sans-serif;
}

*,
*::before,
*::after {
  box-sizing: border-box;
  margin: 0;
  padding: 0;
}

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

body {
  font-family: var(--font-body);
  color: var(--text);
  background:
    radial-gradient(ellipse 90% 50% at 50% -10%, rgba(61, 122, 184, 0.18), transparent 55%),
    radial-gradient(ellipse 60% 40% at 80% 100%, rgba(44, 76, 112, 0.2), transparent 50%),
    linear-gradient(180deg, #030508 0%, var(--bg) 40%, #080d14 100%);
  background-attachment: fixed;
  -webkit-font-smoothing: antialiased;
  line-height: 1.55;
}

.page {
  width: min(100%, var(--max));
  margin: 0 auto;
  padding: 28px 20px 48px;
  min-height: 100vh;
  display: flex;
  flex-direction: column;
  gap: 28px;
}

.hero {
  text-align: center;
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 10px;
  animation: rise 0.7s ease-out both;
}

.hero-logo {
  display: block;
  width: min(100%, 320px);
  height: auto;
  margin: 0 auto -8px;
  filter: drop-shadow(0 12px 28px rgba(61, 122, 184, 0.22));
}

.brand {
  font-family: var(--font-display);
  font-weight: 700;
  font-size: clamp(1.85rem, 7vw, 2.35rem);
  letter-spacing: 0.18em;
  color: var(--text);
  text-indent: 0.18em;
}

.tagline {
  font-size: 0.95rem;
  color: var(--steel-light);
  letter-spacing: 0.12em;
}

.platform-hint {
  margin-top: 4px;
  font-size: 0.82rem;
  color: var(--text-muted);
  min-height: 1.2em;
}

.actions {
  display: flex;
  flex-direction: column;
  gap: 12px;
  animation: rise 0.7s ease-out 0.12s both;
}

.btn {
  appearance: none;
  border: none;
  cursor: pointer;
  width: 100%;
  padding: 16px 20px;
  border-radius: var(--radius);
  font-family: var(--font-body);
  font-size: 1.05rem;
  font-weight: 600;
  letter-spacing: 0.04em;
  transition: transform 0.15s ease, box-shadow 0.2s ease, background 0.2s ease, opacity 0.2s ease;
}

.btn:active {
  transform: scale(0.98);
}

.btn[hidden] {
  display: none !important;
}

.btn-primary {
  color: #f4f8fc;
  background: linear-gradient(135deg, #3d7ab8 0%, #2c4c70 55%, #1e3550 100%);
  box-shadow: 0 10px 28px rgba(45, 90, 140, 0.45);
}

.btn-primary:hover {
  box-shadow: 0 12px 32px rgba(45, 90, 140, 0.55);
}

.btn-secondary {
  color: var(--silver);
  background: var(--bg-elevated);
  border: 1px solid rgba(74, 111, 150, 0.45);
}

.btn-secondary:hover {
  border-color: var(--steel-light);
  background: #101826;
}

.guide {
  background: rgba(12, 18, 28, 0.72);
  border: 1px solid rgba(74, 111, 150, 0.28);
  border-radius: 18px;
  padding: 22px 18px 20px;
  animation: rise 0.7s ease-out 0.22s both;
}

.guide h2 {
  font-size: 1.05rem;
  font-weight: 700;
  margin-bottom: 10px;
  color: var(--text);
  letter-spacing: 0.06em;
}

.guide-lead {
  font-size: 0.88rem;
  color: var(--text-muted);
  margin-bottom: 14px;
}

.guide-list {
  padding-left: 1.15em;
  display: flex;
  flex-direction: column;
  gap: 12px;
  font-size: 0.88rem;
  color: var(--danger-soft);
}

.guide-list strong {
  color: var(--text);
  font-weight: 600;
}

.guide-list code {
  font-family: ui-monospace, SFMono-Regular, Menlo, Consolas, monospace;
  font-size: 0.86em;
  color: #b8d0e8;
  background: rgba(61, 122, 184, 0.15);
  padding: 0.1em 0.35em;
  border-radius: 4px;
}

.footer {
  margin-top: auto;
  text-align: center;
  padding-top: 8px;
  animation: rise 0.7s ease-out 0.3s both;
}

.footer p {
  font-size: 0.72rem;
  letter-spacing: 0.08em;
  color: var(--text-muted);
  text-transform: uppercase;
}

.toast {
  position: fixed;
  left: 50%;
  bottom: calc(28px + env(safe-area-inset-bottom, 0px));
  transform: translateX(-50%) translateY(12px);
  max-width: min(90vw, 360px);
  padding: 12px 18px;
  border-radius: 999px;
  background: rgba(20, 28, 40, 0.95);
  border: 1px solid rgba(74, 111, 150, 0.5);
  color: var(--text);
  font-size: 0.88rem;
  text-align: center;
  box-shadow: 0 12px 32px rgba(0, 0, 0, 0.45);
  opacity: 0;
  pointer-events: none;
  transition: opacity 0.25s ease, transform 0.25s ease;
  z-index: 50;
}

.toast.is-show {
  opacity: 1;
  transform: translateX(-50%) translateY(0);
}

.toast[hidden] {
  display: block !important;
  visibility: hidden;
}

.toast[hidden].is-show {
  visibility: visible;
}

@keyframes rise {
  from {
    opacity: 0;
    transform: translateY(16px);
  }
  to {
    opacity: 1;
    transform: translateY(0);
  }
}

@media (prefers-reduced-motion: reduce) {
  .hero,
  .actions,
  .guide,
  .footer {
    animation: none;
  }

  .btn,
  .toast {
    transition: none;
  }
}