:root {
  color-scheme: light dark;
  font-family: 'Segoe UI', 'Microsoft YaHei', Arial, sans-serif;
  color: #111b21;
  background: #f3f7f6;
  --surface: #ffffff;
  --surface-subtle: #f7faf9;
  --border: #dfe9e6;
  --text: #111b21;
  --text-sub: #5e6f77;
  --primary: #00a884;
  --primary-hover: #008f72;
  --primary-soft: #e4f7f1;
  --shadow: 0 24px 60px rgba(17, 27, 33, 0.14);
}

* {
  box-sizing: border-box;
}

body {
  margin: 0;
  min-width: 280px;
  min-height: 100vh;
  color: var(--text);
  background: radial-gradient(circle at 50% 0%, rgba(0, 168, 132, 0.14), transparent 42%), #f3f7f6;
}

.page-shell {
  min-height: 100vh;
  display: flex;
  align-items: center;
  justify-content: center;
  padding: 28px 18px;
}

.install-card {
  width: min(100%, 600px);
  padding: 34px;
  border: 1px solid var(--border);
  border-radius: 20px;
  background: var(--surface);
  box-shadow: var(--shadow);
}

.brand-row {
  display: flex;
  align-items: center;
  gap: 12px;
}

.brand-mark {
  width: 42px;
  height: 42px;
  display: grid;
  flex: 0 0 42px;
  place-items: center;
}

.brand-mark img {
  display: block;
  width: 100%;
  height: 100%;
  object-fit: contain;
  transform: scale(1.17);
  transform-origin: center;
  user-select: none;
  -webkit-user-select: none;
  -webkit-user-drag: none;
  pointer-events: none;
}

.brand-row strong,
.brand-row small {
  display: block;
}

.brand-row strong {
  font-size: 18px;
  line-height: 24px;
}

.brand-row small {
  margin-top: 1px;
  color: var(--text-sub);
  font-size: 12px;
}

.status-badge {
  width: fit-content;
  display: flex;
  align-items: center;
  gap: 8px;
  margin-top: 28px;
  padding: 7px 11px;
  border-radius: 999px;
  color: #007b60;
  background: var(--primary-soft);
  font-size: 13px;
  font-weight: 600;
}

.status-badge span {
  width: 8px;
  height: 8px;
  border-radius: 50%;
  background: var(--primary);
}

h1 {
  margin: 18px 0 10px;
  font-size: clamp(28px, 6vw, 38px);
  line-height: 1.22;
  letter-spacing: -0.02em;
}

.lead {
  margin: 0;
  color: var(--text-sub);
  font-size: 15px;
  line-height: 1.75;
}

.install-button,
.whatsapp-link {
  display: flex;
  align-items: center;
  justify-content: center;
  text-decoration: none;
}

.install-button {
  min-height: 52px;
  margin-top: 24px;
  border-radius: 10px;
  color: #ffffff;
  background: var(--primary);
  box-shadow: 0 10px 24px rgba(0, 168, 132, 0.22);
  font-size: 16px;
  font-weight: 700;
}

.install-button:hover,
.install-button:focus-visible {
  background: var(--primary-hover);
}

.install-button:focus-visible,
.whatsapp-link:focus-visible {
  outline: 3px solid rgba(0, 168, 132, 0.3);
  outline-offset: 3px;
}

.install-note {
  margin: 10px 0 0;
  color: var(--text-sub);
  font-size: 12px;
  line-height: 1.55;
  text-align: center;
}

.steps {
  display: grid;
  gap: 12px;
  margin: 26px 0 0;
  padding: 0;
  list-style: none;
}

.steps li {
  display: grid;
  grid-template-columns: 32px 1fr;
  column-gap: 12px;
  align-items: center;
  padding: 12px;
  border: 1px solid var(--border);
  border-radius: 10px;
  background: var(--surface-subtle);
}

.steps li > span {
  width: 32px;
  height: 32px;
  display: grid;
  grid-row: 1 / span 2;
  place-items: center;
  border-radius: 50%;
  color: #007b60;
  background: var(--primary-soft);
  font-weight: 700;
}

.steps strong {
  font-size: 14px;
}

.steps small {
  margin-top: 3px;
  color: var(--text-sub);
  font-size: 12px;
  line-height: 1.45;
}

.whatsapp-link {
  min-height: 44px;
  margin-top: 14px;
  border: 1px solid var(--border);
  border-radius: 10px;
  color: var(--text);
  background: var(--surface);
  font-size: 14px;
  font-weight: 600;
}

.whatsapp-link:hover,
.whatsapp-link:focus-visible {
  background: var(--surface-subtle);
}

footer {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 10px;
  margin-top: 24px;
  padding-top: 20px;
  border-top: 1px solid var(--border);
}

footer span,
footer strong {
  display: block;
}

footer span {
  margin-bottom: 5px;
  color: var(--text-sub);
  font-size: 11px;
}

footer strong {
  font-size: 12px;
  line-height: 1.45;
}

@media (max-width: 560px) {
  .page-shell {
    padding: 0;
  }

  .install-card {
    min-height: 100vh;
    padding: 26px 20px;
    border: 0;
    border-radius: 0;
    box-shadow: none;
  }

  footer {
    grid-template-columns: 1fr;
  }
}

@media (prefers-color-scheme: dark) {
  :root {
    color: #e9edef;
    background: #0b141a;
    --surface: #111b21;
    --surface-subtle: #17262d;
    --border: #2a3942;
    --text: #e9edef;
    --text-sub: #aebac1;
    --primary: #00a884;
    --primary-hover: #06cf9c;
    --primary-soft: #103b33;
    --shadow: 0 24px 60px rgba(0, 0, 0, 0.42);
  }

  body {
    background:
      radial-gradient(circle at 50% 0%, rgba(0, 168, 132, 0.18), transparent 42%), #0b141a;
  }

  .status-badge,
  .steps li > span {
    color: #72e6c4;
  }
}