:root {
  --color-primary: #4f46e5;
  --color-primary-hover: #4338ca;
  --color-accent: #22c55e;
  --color-bg: #f8fafc;
  --color-card: #ffffff;
  --color-text: #0f172a;
  --color-muted: #475569;
  --color-border: #e2e8f0;
  --radius: 16px;
  --container: 1120px;
}

* {
  box-sizing: border-box;
}

body {
  margin: 0;
  font-family: "Inter", system-ui, -apple-system, sans-serif;
  color: var(--color-text);
  background: var(--color-bg);
  line-height: 1.6;
}

a {
  color: inherit;
  text-decoration: none;
}

a:hover {
  color: var(--color-primary);
}

.container {
  max-width: var(--container);
  margin: 0 auto;
  padding: 20px 24px;
}

.site-header {
  position: sticky;
  top: 0;
  z-index: 20;
  background: rgba(248, 250, 252, 0.9);
  backdrop-filter: blur(12px);
  border-bottom: 1px solid var(--color-border);
}

.site-header .container {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 24px;
}

.logo {
  display: inline-flex;
  align-items: center;
  gap: 10px;
  font-weight: 700;
  font-size: 1.2rem;
  letter-spacing: -0.02em;
}

.logo-mark {
  width: 14px;
  height: 14px;
  border-radius: 4px;
  background: var(--color-primary);
  display: inline-block;
}

.nav {
  display: flex;
  gap: 16px;
  flex-wrap: wrap;
}

.nav a {
  font-weight: 500;
  color: var(--color-muted);
}

.nav a:hover {
  color: var(--color-text);
}

main {
  padding: 16px 0 56px;
}

.hero {
  margin: 8px 0 28px;
}

.hero h1 {
  font-size: 2.25rem;
  margin: 0 0 8px;
}

.hero p {
  margin: 0;
  color: var(--color-muted);
}

.grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(260px, 1fr));
  gap: 20px;
}

.card {
  background: var(--color-card);
  border: 1px solid var(--color-border);
  border-radius: var(--radius);
  padding: 20px;
  box-shadow: 0 8px 24px rgba(15, 23, 42, 0.08);
}

.card h2 {
  margin-top: 0;
  margin-bottom: 8px;
}

.card p {
  margin: 0 0 12px;
  color: var(--color-muted);
}

.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 8px;
  border-radius: 999px;
  padding: 10px 18px;
  border: 1px solid transparent;
  font-weight: 600;
  cursor: pointer;
}

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

.btn-primary:hover {
  background: var(--color-primary-hover);
  color: #ffffff;
}

.btn-secondary {
  background: transparent;
  border-color: var(--color-border);
  color: var(--color-text);
}

.input {
  width: 100%;
  padding: 10px 12px;
  border: 1px solid var(--color-border);
  border-radius: 10px;
  font-size: 1rem;
}

textarea.input {
  min-height: 160px;
  padding: 12px;
  resize: vertical;
}

.label {
  font-weight: 600;
  margin-bottom: 6px;
  display: inline-block;
}

.help {
  font-size: 0.9rem;
  color: var(--color-muted);
}

.form-row {
  display: grid;
  gap: 12px;
  margin-bottom: 16px;
}

.stack {
  display: grid;
  gap: 16px;
}

.row-inline {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 12px;
}

.check-row {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 12px;
  padding: 8px 12px;
  border: 1px solid var(--color-border);
  border-radius: 10px;
  background: #ffffff;
}

.badge {
  display: inline-flex;
  align-items: center;
  padding: 4px 10px;
  border-radius: 999px;
  background: rgba(79, 70, 229, 0.1);
  color: var(--color-primary);
  font-size: 0.8rem;
  font-weight: 600;
}

.result-card {
  border-left: 4px solid var(--color-primary);
}

.result-number {
  font-size: 2rem;
  font-weight: 700;
  margin: 8px 0;
}

.result-panel {
  border: 1px solid var(--color-border);
  border-radius: var(--radius);
  padding: 18px;
  background: rgba(79, 70, 229, 0.04);
}

.mono {
  font-family: "SFMono-Regular", "SF Mono", Menlo, Consolas, "Liberation Mono", monospace;
  word-break: break-all;
}

.uuid-item {
  display: flex;
  flex-direction: column;
  gap: 4px;
  padding: 12px;
  border: 1px solid var(--color-border);
  border-radius: 12px;
  background: #ffffff;
  cursor: pointer;
}

.uuid-item small {
  color: var(--color-muted);
}

.reading {
  max-width: 70ch;
}

.site-footer {
  border-top: 1px solid var(--color-border);
  padding: 24px 0 32px;
  background: #ffffff;
}

.footer-links {
  display: flex;
  gap: 16px;
  flex-wrap: wrap;
  margin-bottom: 12px;
}

.footer-links a {
  color: var(--color-muted);
  font-weight: 500;
}

.ad-slot {
  border: 1px dashed var(--color-border);
  padding: 16px;
  margin: 16px 0;
  text-align: center;
  color: var(--color-muted);
  background: #ffffff;
  border-radius: var(--radius);
}