:root {
  --brand: #00c8b4;
  --brand-hover: #00b3a1;
  --text: #111827;
  --muted: #4b5563;
  --hint: #9ca3af;
  --bg: #f9fafb;
  --panel: #ffffff;
  --shadow: 0 10px 30px rgba(17, 24, 39, 0.08);
}

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

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

body {
  font-family:
    'Segoe UI',
    system-ui,
    -apple-system,
    BlinkMacSystemFont,
    sans-serif;
  background: var(--bg);
  color: var(--text);
}

.shell {
  min-height: 100dvh;
  display: flex;
  align-items: center;
  justify-content: center;
  padding: 1rem;
}

.panel {
  width: 100%;
  max-width: 28rem;
  background: var(--panel);
  border-radius: 0.75rem;
  box-shadow: var(--shadow);
  padding: 1.5rem;
  text-align: center;
}

.logo {
  display: block;
  margin: 0 auto;
  height: auto;
  max-width: 180px;
}

[hidden] {
  display: none !important;
}

.loading {
  margin-top: 2rem;
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 1rem;
}

.spinner {
  width: 2.5rem;
  height: 2.5rem;
  border-radius: 9999px;
  border: 3px solid #e5e7eb;
  border-top-color: var(--brand);
  animation: spin 0.8s linear infinite;
}

.loading-text {
  margin: 0;
  font-size: 0.875rem;
  color: var(--muted);
  animation: pulse 1.4s ease-in-out infinite;
}

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

@keyframes pulse {
  50% {
    opacity: 0.45;
  }
}

#result {
  margin-top: 1.5rem;
}

.icon-wrap {
  width: 4rem;
  height: 4rem;
  margin: 0 auto;
  border-radius: 9999px;
  display: flex;
  align-items: center;
  justify-content: center;
}

.icon-wrap svg {
  width: 2rem;
  height: 2rem;
}

h1 {
  margin: 0.75rem 0 0.5rem;
  font-size: 1.25rem;
  line-height: 1.3;
  font-weight: 700;
}

.subtitle {
  margin: 0;
  font-size: 0.875rem;
  color: var(--muted);
}

.detail {
  margin: 0.75rem 0 0;
  font-size: 0.75rem;
  color: var(--hint);
}

.btn {
  display: flex;
  align-items: center;
  justify-content: center;
  width: 100%;
  margin-top: 1.5rem;
  padding: 0.75rem 1rem;
  border-radius: 9999px;
  font-size: 0.875rem;
  font-weight: 700;
  text-decoration: none;
  transition: filter 120ms ease, background-color 120ms ease;
}

.btn:focus-visible {
  outline: 2px solid var(--brand);
  outline-offset: 2px;
}

.btn-primary {
  color: #fff;
  background: var(--brand);
}

.btn-primary:hover {
  filter: brightness(0.95);
}