:root {
  --background: #0f172a;
  --surface: #111827;
  --text: #e5e7eb;
  --muted: #94a3b8;
  --primary: #38bdf8;
  --accent: #22c55e;
  --border: rgba(148, 163, 184, 0.2);
  --shadow: 0 25px 50px -12px rgba(15, 23, 42, 0.8);
  font-size: 16px;
}

* {
  box-sizing: border-box;
}

html {
  scroll-behavior: smooth;
}

body {
  margin: 0;
  min-height: 100vh;
  font-family: "Inter", system-ui, -apple-system, BlinkMacSystemFont, "Segoe UI", sans-serif;
  color: var(--text);
  background: radial-gradient(circle at top, rgba(56, 189, 248, 0.15), transparent 55%), var(--background);
  line-height: 1.6;
}

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

a:focus-visible,
button:focus-visible,
input:focus-visible,
select:focus-visible,
textarea:focus-visible {
  outline: 2px solid var(--primary);
  outline-offset: 2px;
}

.skip-link {
  position: absolute;
  top: -100px;
  left: 1rem;
  padding: 0.75rem 1rem;
  background: var(--primary);
  color: #0f172a;
  border-radius: 0.5rem;
  z-index: 999;
  transition: top 0.2s ease-in-out;
}

.skip-link:focus {
  top: 1rem;
}

header {
  position: sticky;
  top: 0;
  z-index: 50;
  backdrop-filter: blur(18px);
  background: rgba(15, 23, 42, 0.9);
  border-bottom: 1px solid var(--border);
}

.navbar {
  max-width: 1200px;
  margin: 0 auto;
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 1rem 1.5rem;
}

.logo {
  font-weight: 700;
  font-size: 1.1rem;
  letter-spacing: 0.08em;
  text-transform: uppercase;
}

nav ul {
  list-style: none;
  display: flex;
  gap: 1rem;
  padding: 0;
  margin: 0;
}

nav a {
  color: var(--muted);
  font-weight: 500;
  padding: 0.4rem 0.8rem;
  border-radius: 0.4rem;
  transition: color 0.2s, background 0.2s;
}

nav a:hover,
nav a[aria-current="page"] {
  color: var(--text);
  background: rgba(56, 189, 248, 0.12);
}

main {
  max-width: 1200px;
  margin: 0 auto;
  padding: 2rem 1.5rem 4rem;
}

section:target {
  scroll-margin-top: 6rem;
}

.hero {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
  gap: 2rem;
  align-items: center;
  padding: 4rem 0 2rem;
}

.hero h1 {
  font-size: clamp(2.25rem, 5vw, 3.5rem);
  line-height: 1.2;
  margin-bottom: 1rem;
}

.hero p {
  color: var(--muted);
  font-size: 1.1rem;
}

.badge {
  display: inline-flex;
  align-items: center;
  gap: 0.4rem;
  padding: 0.35rem 0.75rem;
  border-radius: 999px;
  font-size: 0.85rem;
  text-transform: uppercase;
  letter-spacing: 0.08em;
  background: rgba(56, 189, 248, 0.12);
  color: var(--primary);
}

.card {
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: 1.25rem;
  padding: 1.75rem;
  box-shadow: var(--shadow);
}

.section-title {
  font-size: 1.8rem;
  margin-bottom: 0.5rem;
}

.section-subtitle {
  color: var(--muted);
  margin-bottom: 2rem;
}

.grid {
  display: grid;
  gap: 1.5rem;
}

.grid-2 {
  grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
}

.grid-3 {
  grid-template-columns: repeat(auto-fit, minmax(220px, 1fr));
}

.list-check {
  list-style: none;
  padding: 0;
  margin: 0;
  display: grid;
  gap: 0.8rem;
}

.list-check li {
  display: flex;
  gap: 0.6rem;
  align-items: flex-start;
}

.list-check span {
  color: var(--primary);
  font-weight: 600;
}

.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 0.6rem;
  padding: 0.95rem 1.5rem;
  border-radius: 0.8rem;
  border: none;
  font-weight: 600;
  font-size: 1rem;
  cursor: pointer;
  transition: transform 0.2s ease, box-shadow 0.2s ease;
}

.btn-primary {
  background: var(--primary);
  color: #0f172a;
}

.btn-primary:hover {
  transform: translateY(-2px);
  box-shadow: 0 10px 20px rgba(56, 189, 248, 0.25);
}

.btn-ghost {
  background: transparent;
  color: var(--text);
  border: 1px solid var(--border);
}

.section {
  padding: 3rem 0;
}

.articles-list,
.blog-list {
  display: grid;
  gap: 1.5rem;
  grid-template-columns: repeat(auto-fit, minmax(240px, 1fr));
}

.article-card {
  padding: 1.5rem;
  border-radius: 1rem;
  background: linear-gradient(145deg, rgba(17, 24, 39, 0.95), rgba(15, 23, 42, 0.9));
  border: 1px solid var(--border);
}

.article-card h3 {
  margin-top: 0;
  margin-bottom: 0.6rem;
}

.article-card p {
  color: var(--muted);
}

.test-card form {
  display: grid;
  gap: 1rem;
}

.question {
  border: 1px solid var(--border);
  border-radius: 1rem;
  padding: 1.25rem;
  background: rgba(15, 23, 42, 0.6);
}

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

.question select,
.question input[type="number"] {
  width: 100%;
  padding: 0.75rem;
  border-radius: 0.65rem;
  border: 1px solid var(--border);
  background: rgba(15, 23, 42, 0.8);
  color: var(--text);
}

.result-badge {
  font-size: 1.2rem;
  font-weight: 700;
  color: var(--accent);
}

.result-bar {
  width: 100%;
  height: 10px;
  border-radius: 999px;
  background: rgba(148, 163, 184, 0.2);
  overflow: hidden;
}

.result-bar::after {
  content: "";
  display: block;
  height: 100%;
  width: var(--progress, 0%);
  background: linear-gradient(90deg, var(--primary), var(--accent));
  transition: width 0.4s ease;
}

footer {
  border-top: 1px solid var(--border);
  background: rgba(15, 23, 42, 0.95);
  padding: 2rem 1.5rem;
}

footer .footer-content {
  max-width: 1200px;
  margin: 0 auto;
  display: flex;
  flex-wrap: wrap;
  gap: 1.5rem;
  justify-content: space-between;
}

footer small {
  color: var(--muted);
}

.article-content {
  max-width: 780px;
  margin: 0 auto;
}

.article-content h1 {
  font-size: 2.4rem;
}

.article-content h2 {
  font-size: 1.5rem;
  margin-top: 2rem;
}

.article-content p {
  color: #cbd5f5;
}

.cta-panel {
  margin-top: 2rem;
  padding: 2rem;
  border-radius: 1.5rem;
  background: radial-gradient(circle at top right, rgba(34, 197, 94, 0.15), rgba(15, 23, 42, 0.9));
  border: 1px solid rgba(34, 197, 94, 0.3);
}

.table-style {
  width: 100%;
  border-collapse: collapse;
  background: rgba(15, 23, 42, 0.6);
  border-radius: 1rem;
  overflow: hidden;
}

.table-style th,
.table-style td {
  padding: 1rem;
  border-bottom: 1px solid var(--border);
  text-align: left;
}

.table-style th {
  font-size: 0.95rem;
  text-transform: uppercase;
  letter-spacing: 0.08em;
  color: var(--muted);
}

@media (max-width: 720px) {
  .navbar {
    flex-direction: column;
    gap: 1rem;
  }

  nav ul {
    flex-wrap: wrap;
    justify-content: center;
  }

  .hero {
    padding-top: 2.5rem;
  }

  .card {
    padding: 1.25rem;
  }
}