:root {
  --bg: #ffffff;
  --bg-subtle: #f6f7fb;
  --text: #0f172a;
  --text-muted: #64748b;
  --border: #e5e7eb;
  --accent: #4f46e5;
  --accent-dark: #4338ca;
  --accent-tint: #eef2ff;
  --radius: 12px;
  --max-width: 1120px;
  --max-width-article: 760px;
}

* {
  box-sizing: border-box;
}

html {
  -webkit-text-size-adjust: 100%;
}

body {
  margin: 0;
  background: var(--bg);
  color: var(--text);
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, Helvetica, Arial, sans-serif;
  line-height: 1.5;
  -webkit-font-smoothing: antialiased;
}

img {
  max-width: 100%;
  display: block;
}

a {
  color: var(--accent);
  text-decoration: none;
}

a:hover {
  color: var(--accent-dark);
}

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

/* Header */

.site-header {
  position: sticky;
  top: 0;
  z-index: 10;
  background: rgba(255, 255, 255, 0.9);
  backdrop-filter: blur(8px);
  border-bottom: 1px solid var(--border);
}

.site-header__inner {
  max-width: var(--max-width);
  margin: 0 auto;
  padding: 16px 24px;
  display: flex;
  align-items: center;
  justify-content: space-between;
}

.site-logo {
  font-size: 1.25rem;
  font-weight: 800;
  color: var(--text);
  letter-spacing: -0.02em;
}

.site-logo span {
  color: var(--accent);
}

.site-nav {
  display: flex;
  align-items: center;
  gap: 24px;
}

.site-nav a {
  color: var(--text-muted);
  font-weight: 600;
  font-size: 0.95rem;
}

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

/* Hero */

.hero {
  padding: 72px 24px 56px;
  text-align: center;
}

.hero h1 {
  font-size: 2.75rem;
  font-weight: 800;
  letter-spacing: -0.03em;
  margin: 0 0 16px;
  max-width: 720px;
  margin-left: auto;
  margin-right: auto;
}

.hero p {
  color: var(--text-muted);
  font-size: 1.15rem;
  max-width: 620px;
  margin: 0 auto;
}

/* Article grid */

.article-grid {
  max-width: var(--max-width);
  margin: 0 auto;
  padding: 16px 24px 64px;
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(300px, 1fr));
  gap: 24px;
}

.article-card {
  border: 1px solid var(--border);
  border-radius: var(--radius);
  overflow: hidden;
  background: var(--bg);
  transition: transform 0.15s ease, box-shadow 0.15s ease;
  display: flex;
  flex-direction: column;
}

.article-card:hover {
  transform: translateY(-4px);
  box-shadow: 0 12px 24px -12px rgba(15, 23, 42, 0.18);
}

.article-card__image {
  aspect-ratio: 16 / 9;
  width: 100%;
  object-fit: cover;
  background: var(--bg-subtle);
}

.article-card__body {
  padding: 20px;
  display: flex;
  flex-direction: column;
  gap: 10px;
  flex: 1;
}

.badge {
  display: inline-block;
  background: var(--accent-tint);
  color: var(--accent-dark);
  font-size: 0.75rem;
  font-weight: 700;
  text-transform: uppercase;
  letter-spacing: 0.04em;
  padding: 4px 10px;
  border-radius: 999px;
  width: fit-content;
}

.article-card__title {
  font-size: 1.15rem;
  font-weight: 700;
  color: var(--text);
  letter-spacing: -0.01em;
  margin: 0;
}

.article-card__excerpt {
  color: var(--text-muted);
  font-size: 0.95rem;
  margin: 0;
  flex: 1;
}

.article-card__link {
  font-weight: 700;
  font-size: 0.9rem;
}

.empty-state {
  max-width: var(--max-width);
  margin: 0 auto;
  padding: 48px 24px;
  text-align: center;
  color: var(--text-muted);
}

/* Ad slots */

.ad-slot {
  border: 2px dashed var(--border);
  background: var(--bg-subtle);
  border-radius: var(--radius);
  padding: 28px 16px;
  text-align: center;
  color: var(--text-muted);
  font-size: 0.85rem;
  margin: 32px auto;
  max-width: var(--max-width);
}

.ad-slot--article {
  max-width: var(--max-width-article);
}

/* Article detail */

.article {
  max-width: var(--max-width-article);
  margin: 0 auto;
  padding: 48px 24px 64px;
}

.article__back {
  font-weight: 600;
  font-size: 0.9rem;
  display: inline-block;
  margin-bottom: 24px;
}

.article__meta {
  display: flex;
  align-items: center;
  gap: 12px;
  margin-bottom: 16px;
  color: var(--text-muted);
  font-size: 0.9rem;
}

.article h1 {
  font-size: 2.25rem;
  font-weight: 800;
  letter-spacing: -0.02em;
  margin: 0 0 24px;
}

.article__featured-image {
  width: 100%;
  border-radius: var(--radius);
  margin-bottom: 32px;
}

.article-body {
  font-size: 1.08rem;
  line-height: 1.8;
  color: var(--text);
}

.article-body h2 {
  font-size: 1.5rem;
  font-weight: 800;
  margin: 40px 0 16px;
  letter-spacing: -0.01em;
}

.article-body h3 {
  font-size: 1.2rem;
  font-weight: 700;
  margin: 32px 0 12px;
}

.article-body p {
  margin: 0 0 20px;
}

.article-body a {
  text-decoration: underline;
}

.article-body ul,
.article-body ol {
  margin: 0 0 20px;
  padding-left: 24px;
}

.article-body li {
  margin-bottom: 8px;
}

.article-body blockquote {
  border-left: 3px solid var(--accent);
  margin: 24px 0;
  padding: 4px 20px;
  color: var(--text-muted);
  font-style: italic;
}

.article-body img {
  border-radius: var(--radius);
  margin: 24px 0;
}

/* Footer */

.site-footer {
  border-top: 1px solid var(--border);
  padding: 32px 24px;
  text-align: center;
  color: var(--text-muted);
  font-size: 0.85rem;
}

.site-footer__nav {
  display: flex;
  justify-content: center;
  gap: 20px;
  margin-bottom: 12px;
}

.site-footer__nav a {
  color: var(--text-muted);
  font-weight: 600;
}

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

.site-footer p {
  margin: 0;
}

/* Category filter chips */

.category-filters {
  max-width: var(--max-width);
  margin: 0 auto;
  padding: 0 24px 8px;
  display: flex;
  flex-wrap: wrap;
  gap: 10px;
}

.category-filters a {
  display: inline-block;
  padding: 6px 14px;
  border-radius: 999px;
  border: 1px solid var(--border);
  color: var(--text-muted);
  font-size: 0.85rem;
  font-weight: 600;
}

.category-filters a:hover {
  border-color: var(--accent);
  color: var(--accent);
}

.category-filters a.is-active {
  background: var(--accent);
  border-color: var(--accent);
  color: #fff;
}

@media (max-width: 640px) {
  .hero {
    padding: 48px 20px 40px;
  }

  .hero h1 {
    font-size: 2rem;
  }

  .article h1 {
    font-size: 1.75rem;
  }

  .article-body {
    font-size: 1.02rem;
  }
}

/* Contact form */

.contact-form {
  margin-top: 32px;
  display: flex;
  flex-direction: column;
  gap: 20px;
  max-width: 480px;
}

.form-field {
  display: flex;
  flex-direction: column;
  gap: 6px;
}

.form-field label {
  font-weight: 600;
  font-size: 0.9rem;
  color: var(--text);
}

.form-field input,
.form-field textarea {
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 10px 14px;
  font-size: 1rem;
  font-family: inherit;
  color: var(--text);
  background: var(--bg);
}

.form-field input:focus,
.form-field textarea:focus {
  outline: none;
  border-color: var(--accent);
}

.form-field--honeypot {
  position: absolute;
  left: -9999px;
  top: -9999px;
}

.button-primary {
  align-self: flex-start;
  background: var(--accent);
  color: #fff;
  border: none;
  border-radius: var(--radius);
  padding: 12px 24px;
  font-size: 1rem;
  font-weight: 700;
  cursor: pointer;
  transition: background 0.15s ease;
}

.button-primary:hover {
  background: var(--accent-dark);
}

.form-notice {
  margin-top: 24px;
  padding: 14px 18px;
  border-radius: var(--radius);
  font-size: 0.95rem;
  max-width: 480px;
}

.form-notice--success {
  background: var(--accent-tint);
  color: var(--accent-dark);
}

.form-notice--error {
  background: #fef2f2;
  color: #b91c1c;
}