/* ============================================
   ENG2ARC — Site Styles
   Clean, professional, content-first
   ============================================ */

/* --- Reset & Base --- */
*, *::before, *::after { box-sizing: border-box; margin: 0; padding: 0; }

:root {
  --color-bg: #fafaf9;
  --color-surface: #ffffff;
  --color-text: #1a1a1a;
  --color-text-secondary: #5a5a5a;
  --color-text-muted: #8a8a8a;
  --color-accent: #1a5276;
  --color-accent-light: #2980b9;
  --color-border: #e5e5e5;
  --color-border-light: #f0f0f0;
  --color-highlight: #eaf2f8;
  --font-body: 'Inter', -apple-system, BlinkMacSystemFont, sans-serif;
  --font-serif: 'Newsreader', Georgia, 'Times New Roman', serif;
  --max-width: 720px;
  --nav-height: 64px;
}

html { font-size: 17px; scroll-behavior: smooth; }

body {
  font-family: var(--font-body);
  color: var(--color-text);
  background: var(--color-bg);
  line-height: 1.7;
  -webkit-font-smoothing: antialiased;
}

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

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

/* --- Navigation --- */
.site-nav {
  position: sticky;
  top: 0;
  z-index: 100;
  background: rgba(250, 250, 249, 0.92);
  backdrop-filter: blur(12px);
  -webkit-backdrop-filter: blur(12px);
  border-bottom: 1px solid var(--color-border);
}

.nav-inner {
  max-width: 960px;
  margin: 0 auto;
  padding: 0 1.5rem;
  height: var(--nav-height);
  display: flex;
  align-items: center;
  justify-content: space-between;
}

.nav-logo {
  font-size: 1.35rem;
  font-weight: 700;
  text-decoration: none;
  letter-spacing: -0.02em;
}

.logo-eng { color: var(--color-text); }
.logo-2 { color: var(--color-accent-light); }
.logo-arc { color: var(--color-text); }

.nav-links {
  display: flex;
  gap: 2rem;
}

.nav-links a {
  color: var(--color-text-secondary);
  font-size: 0.9rem;
  font-weight: 500;
  text-decoration: none;
  transition: color 0.15s;
}

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

.nav-toggle {
  display: none;
  flex-direction: column;
  gap: 5px;
  background: none;
  border: none;
  cursor: pointer;
  padding: 4px;
}

.nav-toggle span {
  width: 22px;
  height: 2px;
  background: var(--color-text);
  border-radius: 1px;
}

/* --- Main Content --- */
main {
  min-height: calc(100vh - var(--nav-height) - 200px);
}

/* --- Hero (Homepage) --- */
.hero {
  max-width: 960px;
  margin: 0 auto;
  padding: 5rem 1.5rem 4rem;
}

.hero-tagline {
  font-family: var(--font-serif);
  font-size: 2.5rem;
  font-weight: 600;
  line-height: 1.2;
  color: var(--color-text);
  max-width: 640px;
  letter-spacing: -0.02em;
}

.hero-subtitle {
  font-size: 1.15rem;
  color: var(--color-text-secondary);
  margin-top: 1.25rem;
  max-width: 560px;
  line-height: 1.65;
}

.hero-author {
  margin-top: 2rem;
  display: flex;
  align-items: center;
  gap: 1rem;
}

.hero-author-info {
  display: flex;
  flex-direction: column;
}

.hero-author-name {
  font-weight: 600;
  color: var(--color-text);
}

.hero-author-role {
  font-size: 0.85rem;
  color: var(--color-text-muted);
}

.hero-cta {
  margin-top: 2.5rem;
  display: flex;
  gap: 1rem;
  flex-wrap: wrap;
}

.btn {
  display: inline-block;
  padding: 0.65rem 1.5rem;
  border-radius: 6px;
  font-size: 0.9rem;
  font-weight: 500;
  text-decoration: none;
  transition: all 0.15s;
}

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

.btn-primary:hover {
  background: var(--color-accent-light);
  color: #fff;
}

.btn-secondary {
  background: transparent;
  color: var(--color-accent);
  border: 1.5px solid var(--color-border);
}

.btn-secondary:hover {
  border-color: var(--color-accent);
}

/* --- Sections --- */
.section {
  max-width: 960px;
  margin: 0 auto;
  padding: 3rem 1.5rem;
}

.section-header {
  display: flex;
  justify-content: space-between;
  align-items: baseline;
  margin-bottom: 2rem;
}

.section-title {
  font-size: 1.3rem;
  font-weight: 600;
  color: var(--color-text);
}

.section-link {
  font-size: 0.85rem;
  font-weight: 500;
}

/* --- Article Cards --- */
.article-grid {
  display: grid;
  gap: 1.5rem;
}

.article-card {
  background: var(--color-surface);
  border: 1px solid var(--color-border);
  border-radius: 8px;
  padding: 1.75rem;
  text-decoration: none;
  display: block;
  transition: border-color 0.15s, box-shadow 0.15s;
}

.article-card:hover {
  border-color: var(--color-accent-light);
  box-shadow: 0 2px 12px rgba(0,0,0,0.04);
}

.article-card-meta {
  display: flex;
  gap: 0.75rem;
  align-items: center;
  margin-bottom: 0.75rem;
  font-size: 0.8rem;
  color: var(--color-text-muted);
}

.article-card-pillar {
  font-size: 0.75rem;
  font-weight: 600;
  text-transform: uppercase;
  letter-spacing: 0.05em;
  color: var(--color-accent);
}

.article-card h3 {
  font-size: 1.15rem;
  font-weight: 600;
  color: var(--color-text);
  line-height: 1.35;
  margin-bottom: 0.5rem;
}

.article-card p {
  font-size: 0.9rem;
  color: var(--color-text-secondary);
  line-height: 1.55;
}

/* --- Pillars Section --- */
.pillars-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(180px, 1fr));
  gap: 1rem;
}

.pillar-card {
  background: var(--color-surface);
  border: 1px solid var(--color-border-light);
  border-radius: 8px;
  padding: 1.25rem;
}

.pillar-card-number {
  font-size: 0.75rem;
  font-weight: 600;
  color: var(--color-accent-light);
  text-transform: uppercase;
  letter-spacing: 0.06em;
}

.pillar-card h4 {
  font-size: 0.95rem;
  font-weight: 600;
  margin-top: 0.35rem;
  color: var(--color-text);
}

.pillar-card p {
  font-size: 0.8rem;
  color: var(--color-text-secondary);
  margin-top: 0.35rem;
  line-height: 1.5;
}

/* --- Article Page --- */
.article {
  max-width: var(--max-width);
  margin: 0 auto;
  padding: 3rem 1.5rem 2rem;
}

.article-header {
  margin-bottom: 2.5rem;
}

.article-meta {
  display: flex;
  gap: 0.75rem;
  align-items: center;
  font-size: 0.8rem;
  color: var(--color-text-muted);
  margin-bottom: 1rem;
}

.article-pillar {
  font-size: 0.75rem;
  font-weight: 600;
  text-transform: uppercase;
  letter-spacing: 0.05em;
  color: var(--color-accent);
  background: var(--color-highlight);
  padding: 0.2rem 0.6rem;
  border-radius: 4px;
}

.article-header h1 {
  font-family: var(--font-serif);
  font-size: 2.2rem;
  font-weight: 600;
  line-height: 1.2;
  letter-spacing: -0.02em;
}

.article-subtitle {
  font-size: 1.1rem;
  color: var(--color-text-secondary);
  margin-top: 0.75rem;
  line-height: 1.55;
}

.article-body {
  font-family: var(--font-serif);
  font-size: 1.05rem;
  line-height: 1.8;
}

.article-body h2 {
  font-family: var(--font-body);
  font-size: 1.3rem;
  font-weight: 600;
  margin-top: 2.5rem;
  margin-bottom: 0.75rem;
  color: var(--color-text);
}

.article-body h3 {
  font-family: var(--font-body);
  font-size: 1.1rem;
  font-weight: 600;
  margin-top: 2rem;
  margin-bottom: 0.5rem;
}

.article-body p {
  margin-bottom: 1.25rem;
}

.article-body blockquote {
  border-left: 3px solid var(--color-accent-light);
  padding: 0.75rem 1.25rem;
  margin: 1.5rem 0;
  background: var(--color-highlight);
  border-radius: 0 6px 6px 0;
  font-style: italic;
}

.article-body strong {
  font-weight: 600;
  color: var(--color-text);
}

.article-body ul, .article-body ol {
  margin: 1rem 0 1.25rem 1.5rem;
}

.article-body li {
  margin-bottom: 0.35rem;
}

.article-footer {
  display: flex;
  justify-content: space-between;
  align-items: center;
  padding-top: 2rem;
  margin-top: 3rem;
  border-top: 1px solid var(--color-border);
}

.article-author strong {
  display: block;
  font-size: 0.9rem;
}

.article-author span {
  font-size: 0.8rem;
  color: var(--color-text-muted);
}

.article-share a {
  font-size: 0.85rem;
  font-weight: 500;
}

.article-nav {
  max-width: var(--max-width);
  margin: 0 auto;
  padding: 1rem 1.5rem 3rem;
}

.article-nav a {
  font-size: 0.85rem;
  font-weight: 500;
}

/* --- Page --- */
.page {
  max-width: var(--max-width);
  margin: 0 auto;
  padding: 3rem 1.5rem;
}

.page-title {
  font-family: var(--font-serif);
  font-size: 2.2rem;
  font-weight: 600;
  margin-bottom: 2rem;
  letter-spacing: -0.02em;
}

.page-body {
  font-family: var(--font-serif);
  font-size: 1.05rem;
  line-height: 1.8;
}

.page-body h2 {
  font-family: var(--font-body);
  font-size: 1.3rem;
  font-weight: 600;
  margin-top: 2.5rem;
  margin-bottom: 0.75rem;
}

.page-body h3 {
  font-family: var(--font-body);
  font-size: 1.1rem;
  font-weight: 600;
  margin-top: 2rem;
  margin-bottom: 0.5rem;
}

.page-body p {
  margin-bottom: 1.25rem;
}

.page-body blockquote {
  border-left: 3px solid var(--color-accent-light);
  padding: 0.75rem 1.25rem;
  margin: 1.5rem 0;
  background: var(--color-highlight);
  border-radius: 0 6px 6px 0;
  font-style: italic;
}

.page-body ul, .page-body ol {
  margin: 1rem 0 1.25rem 1.5rem;
}

.page-body li {
  margin-bottom: 0.35rem;
}

/* --- Articles List Page --- */
.articles-list {
  max-width: 960px;
  margin: 0 auto;
  padding: 3rem 1.5rem;
}

.articles-list h1 {
  font-family: var(--font-serif);
  font-size: 2rem;
  font-weight: 600;
  margin-bottom: 0.5rem;
}

.articles-list > p {
  color: var(--color-text-secondary);
  margin-bottom: 2.5rem;
}

/* --- Newsletter Section --- */
.newsletter-box {
  background: var(--color-accent);
  color: #fff;
  border-radius: 10px;
  padding: 2.5rem;
  text-align: center;
  margin: 2rem 0;
}

.newsletter-box h3 {
  font-size: 1.25rem;
  font-weight: 600;
  margin-bottom: 0.5rem;
}

.newsletter-box p {
  font-size: 0.95rem;
  opacity: 0.9;
  margin-bottom: 1.25rem;
  max-width: 480px;
  margin-left: auto;
  margin-right: auto;
}

.newsletter-box .btn {
  background: #fff;
  color: var(--color-accent);
  font-weight: 600;
}

.newsletter-box .btn:hover {
  background: var(--color-highlight);
  color: var(--color-accent);
}

/* --- Footer --- */
.site-footer {
  border-top: 1px solid var(--color-border);
  margin-top: 4rem;
}

.footer-inner {
  max-width: 960px;
  margin: 0 auto;
  padding: 2.5rem 1.5rem;
  text-align: center;
}

.footer-brand {
  margin-bottom: 1rem;
}

.footer-brand p {
  font-size: 0.85rem;
  color: var(--color-text-muted);
  margin-top: 0.25rem;
}

.footer-links {
  display: flex;
  justify-content: center;
  gap: 1.5rem;
  margin-bottom: 1.5rem;
}

.footer-links a {
  font-size: 0.85rem;
  color: var(--color-text-secondary);
}

.footer-links a:hover {
  color: var(--color-accent);
}

.footer-copy {
  font-size: 0.75rem;
  color: var(--color-text-muted);
}

/* --- Responsive --- */
@media (max-width: 768px) {
  html { font-size: 16px; }

  .hero { padding: 3rem 1.25rem 2.5rem; }
  .hero-tagline { font-size: 1.85rem; }
  .hero-subtitle { font-size: 1.05rem; }

  .nav-links {
    display: none;
    position: absolute;
    top: var(--nav-height);
    left: 0;
    right: 0;
    background: var(--color-bg);
    border-bottom: 1px solid var(--color-border);
    flex-direction: column;
    padding: 1rem 1.5rem;
    gap: 0.75rem;
  }

  .nav-links.open { display: flex; }
  .nav-toggle { display: flex; }

  .article-header h1, .page-title { font-size: 1.7rem; }
  .pillars-grid { grid-template-columns: 1fr 1fr; }
  .article-footer { flex-direction: column; gap: 1rem; align-items: flex-start; }
}

@media (max-width: 480px) {
  .pillars-grid { grid-template-columns: 1fr; }
  .hero-cta { flex-direction: column; }
  .btn { text-align: center; }
}