:root {
  --bg: #0b1220;
  --surface: #111c31;
  --surface-soft: #17253f;
  --border: #2f3f5f;
  --text: #e6edf7;
  --muted: #b2bfd3;
  --accent: #67e8a0;
  --accent-ink: #063118;
}

* {
  box-sizing: border-box;
}

body {
  margin: 0;
  min-height: 100vh;
  display: flex;
  flex-direction: column;
  font-family: Inter, "Segoe UI", Roboto, Helvetica, Arial, sans-serif;
  line-height: 1.45;
  color: var(--text);
  background:
    radial-gradient(circle at 20% -10%, #1e3357 0%, transparent 45%),
    var(--bg);
}

a {
  color: #a7d7ff;
}

header {
  position: sticky;
  top: 0;
  z-index: 20;
  border-bottom: 1px solid var(--border);
  background: rgba(11, 18, 32, 0.92);
  backdrop-filter: blur(8px);
}

.site-header-inner {
  max-width: 1120px;
  margin: 0 auto;
  padding: 0.9rem 1rem;
  display: flex;
  flex-wrap: wrap;
  gap: 0.8rem 1rem;
  align-items: center;
  justify-content: space-between;
}

.brand {
  display: inline-flex;
  align-items: center;
  gap: 0.55rem;
  text-decoration: none;
  color: var(--text);
  font-weight: 700;
}

.brand-logo {
  width: 32px;
  height: 32px;
  object-fit: contain;
}

.brand-name {
  letter-spacing: 0.01em;
}

nav {
  display: flex;
  flex-wrap: wrap;
  gap: 0.45rem;
}

nav a {
  border: 1px solid #43557a;
  border-radius: 999px;
  color: var(--text);
  text-decoration: none;
  font-size: 0.86rem;
  padding: 0.35rem 0.7rem;
  transition: border-color 0.2s ease, transform 0.15s ease;
}

nav a:hover,
nav a:focus-visible {
  border-color: var(--accent);
  transform: translateY(-1px);
}

main {
  flex: 1;
  width: 100%;
  max-width: 980px;
  margin: 1.5rem auto 2.2rem;
  padding: 0 1rem;
}

.card {
  border: 1px solid var(--border);
  border-radius: 14px;
  background: linear-gradient(180deg, var(--surface) 0%, var(--surface-soft) 100%);
  box-shadow: 0 12px 30px rgba(2, 8, 23, 0.25);
  padding: 1.15rem;
}

.card + .card {
  margin-top: 1rem;
}

h1,
h2,
h3 {
  margin-top: 0;
}

.grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(220px, 1fr));
  gap: 0.8rem;
}

label {
  display: block;
  margin-bottom: 0.25rem;
  font-weight: 600;
}

input {
  width: 100%;
  border-radius: 10px;
  border: 1px solid #4a5f88;
  background: #0c1628;
  color: var(--text);
  font-size: 1rem;
  padding: 0.56rem 0.7rem;
}

button {
  margin-top: 1rem;
  border: none;
  border-radius: 10px;
  background: var(--accent);
  color: var(--accent-ink);
  font-weight: 700;
  padding: 0.58rem 0.95rem;
  cursor: pointer;
}

.result {
  margin-top: 1rem;
  color: #bdf8d7;
  font-weight: 600;
}

small {
  display: block;
  color: var(--muted);
  margin-bottom: 0.45rem;
}

ul {
  margin: 0.5rem 0;
  padding-left: 1.1rem;
}

li {
  margin: 0.3rem 0;
}

.seo h2 {
  margin-bottom: 0.35rem;
}

.seo h3 {
  margin: 0.75rem 0 0.3rem;
}

@media (max-width: 640px) {
  .site-header-inner {
    align-items: flex-start;
  }

  nav a {
    font-size: 0.8rem;
  }
}


footer {
  border-top: 1px solid var(--border);
  background: rgba(11, 18, 32, 0.92);
}

.site-footer-inner {
  max-width: 1120px;
  margin: 0 auto;
  padding: 0.9rem 1rem;
  display: flex;
  justify-content: space-between;
  align-items: center;
  gap: 0.8rem;
  color: var(--muted);
}

.footer-link {
  border: 1px solid #43557a;
  border-radius: 999px;
  color: var(--text);
  text-decoration: none;
  font-size: 0.86rem;
  padding: 0.35rem 0.7rem;
}

.footer-link:hover,
.footer-link:focus-visible {
  border-color: var(--accent);
}

@media (max-width: 640px) {
  .site-footer-inner {
    flex-direction: column;
    align-items: flex-start;
  }
}