:root {
  --bg: #f7f8fa;
  --surface: #ffffff;
  --text: #1d2433;
  --muted: #5a6478;
  --primary: #2457ff;
  --border: #dce1ea;
  --radius: 14px;
  --shadow: 0 6px 20px rgba(13, 26, 52, 0.08);
}

* {
  box-sizing: border-box;
}

body {
  margin: 0;
  font-family: "Segoe UI", Roboto, Arial, sans-serif;
  line-height: 1.6;
  color: var(--text);
  background: var(--bg);
}

.container {
  width: min(960px, 92%);
  margin: 0 auto;
}

.skip-link {
  position: absolute;
  left: -9999px;
  top: auto;
}

.skip-link:focus {
  left: 1rem;
  top: 1rem;
  background: #000;
  color: #fff;
  padding: 0.5rem 0.75rem;
  border-radius: 6px;
}

.site-header {
  padding: 3.2rem 0 2.2rem;
  background: linear-gradient(135deg, #eaf0ff 0%, #f7f8fa 70%);
}

.eyebrow {
  margin: 0;
  color: var(--primary);
  font-weight: 700;
  letter-spacing: 0.04em;
  text-transform: uppercase;
  font-size: 0.75rem;
}

h1 {
  margin: 0.35rem 0 0.6rem;
  font-size: clamp(1.8rem, 4vw, 2.4rem);
}

.intro {
  margin: 0;
  max-width: 680px;
  color: var(--muted);
}

.site-nav {
  background: var(--surface);
  border-top: 1px solid var(--border);
  border-bottom: 1px solid var(--border);
}

.nav-inner {
  display: flex;
  gap: 0.8rem;
  flex-wrap: wrap;
  padding: 0.8rem 0;
}

.site-nav a {
  color: var(--text);
  text-decoration: none;
  padding: 0.35rem 0.6rem;
  border-radius: 8px;
}

.site-nav a:hover,
.site-nav a:focus-visible {
  background: #edf1ff;
}

main {
  padding: 1.4rem 0 2.2rem;
}

.card {
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  box-shadow: var(--shadow);
  padding: 1.1rem 1.1rem;
  margin-bottom: 1rem;
}

.section-head {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 0.8rem;
}

h2 {
  margin: 0;
  font-size: 1.2rem;
}

.section-description {
  color: var(--muted);
  margin: 0.45rem 0 0.9rem;
}

button {
  border: 1px solid var(--primary);
  background: var(--primary);
  color: #fff;
  border-radius: 10px;
  padding: 0.45rem 0.7rem;
  cursor: pointer;
  font: inherit;
}

button:hover,
button:focus-visible {
  opacity: 0.92;
}

.post-list {
  list-style: none;
  margin: 0;
  padding: 0;
  display: grid;
  gap: 0.7rem;
}

.post-item {
  border: 1px solid var(--border);
  border-radius: 12px;
  padding: 0.75rem 0.85rem;
  background: #fff;
}

.post-item h3 {
  margin: 0 0 0.35rem;
  font-size: 1rem;
}

.post-item p {
  margin: 0;
  color: #2f3748;
}

.meta {
  margin-top: 0.4rem !important;
  font-size: 0.86rem;
  color: var(--muted) !important;
}

.featured {
  border-color: #b9c9ff;
  background: #f3f6ff;
}

.post-list.highlight .post-item {
  border-width: 2px;
}

.post-list.highlight .featured {
  border-color: var(--primary);
}

.principle-list {
  margin: 0.6rem 0 0;
  padding-left: 1.2rem;
}

.site-footer {
  border-top: 1px solid var(--border);
  padding: 1.5rem 0 2rem;
  color: var(--muted);
  font-size: 0.9rem;
}

.footer-content {
  display: flex;
  justify-content: space-between;
  align-items: center;
  flex-wrap: wrap;
  gap: 1rem;
}

.footer-content p {
  margin: 0;
}

.footer-links {
  display: flex;
  gap: 1.5rem;
}

.footer-links a {
  color: var(--muted);
  text-decoration: none;
}

.footer-links a:hover {
  color: var(--primary);
  text-decoration: underline;
}

/* Article Page Specific Styles */
.article-page {
  padding: 2.5rem 2rem;
}

.article-page h1 {
  font-size: clamp(1.6rem, 3vw, 2.2rem);
  margin-bottom: 0.5rem;
  line-height: 1.3;
}

.article-page .meta {
  font-size: 0.95rem;
  margin-bottom: 2rem;
  border-bottom: 1px solid var(--border);
  padding-bottom: 1rem;
}

.article-content {
  font-size: 1.05rem;
  line-height: 1.8;
  color: #2f3748;
}

.article-content h2 {
  font-size: 1.4rem;
  margin: 2.5rem 0 1rem;
  color: var(--text);
}

.article-content p {
  margin-bottom: 1.2rem;
}

.article-content .principle-list {
  margin-bottom: 1.5rem;
  background: #f8fafe;
  padding: 1.5rem 1.5rem 1.5rem 2.5rem;
  border-radius: 8px;
  border: 1px solid #e1e8fa;
}

.article-content .principle-list li {
  margin-bottom: 0.5rem;
}