@import url('https://fonts.googleapis.com/css2?family=Inter:wght@400;500;600;700;800;900&display=swap');

:root {
  --bg: #FFFFFF;
  --bg-subtle: #F7F7F7;
  --text: #0A0A0A;
  --text-muted: #6B6B6B;
  --text-light: #A3A3A3;
  --border: #E5E5E5;
  --green: #25D366;
  --green-dark: #128C7E;
  --accent: #0A0A0A;
  --tag-bg: #F0FDF4;
  --tag-text: #128C7E;
  --font-head: 'Inter', sans-serif;
  --font-body: 'Inter', sans-serif;
}

*, *::before, *::after { box-sizing: border-box; margin: 0; padding: 0; }
html { font-size: 16px; scroll-behavior: smooth; }

body {
  background: var(--bg);
  color: var(--text);
  font-family: var(--font-body);
  font-weight: 400;
  line-height: 1.6;
  -webkit-font-smoothing: antialiased;
}

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

/* ── NAV ── */
.nav {
  position: sticky;
  top: 0;
  z-index: 100;
  background: rgba(255,255,255,0.95);
  backdrop-filter: blur(16px);
  border-bottom: 1px solid var(--border);
  padding: 0 2rem;
  height: 56px;
  display: flex;
  align-items: center;
  justify-content: space-between;
}

.nav-logo {
  font-family: var(--font-head);
  font-weight: 800;
  font-size: 0.9375rem;
  letter-spacing: -0.02em;
  display: flex;
  align-items: center;
  gap: 0.5rem;
  color: var(--text);
}

.nav-logo span {
  display: inline-block;
  width: 7px;
  height: 7px;
  background: var(--green);
  border-radius: 50%;
}

.nav-links {
  display: flex;
  gap: 2rem;
  list-style: none;
}

.nav-links a {
  font-size: 0.8125rem;
  font-weight: 500;
  color: var(--text-muted);
  transition: color 0.15s;
  letter-spacing: 0.01em;
}

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

/* ── HERO ── */
.hero {
  max-width: 960px;
  margin: 0 auto;
  padding: 5rem 2rem 4rem;
  border-bottom: 1px solid var(--border);
}

.hero-label {
  font-size: 0.6875rem;
  font-weight: 700;
  letter-spacing: 0.15em;
  text-transform: uppercase;
  color: var(--green-dark);
  margin-bottom: 1.25rem;
}

.hero h1 {
  font-family: var(--font-head);
  font-size: clamp(2.75rem, 7vw, 5rem);
  font-weight: 900;
  letter-spacing: -0.04em;
  line-height: 1.0;
  margin-bottom: 1.5rem;
  color: var(--text);
}

.hero p {
  font-size: 1.0625rem;
  color: var(--text-muted);
  max-width: 480px;
  line-height: 1.7;
  font-weight: 400;
}

/* ── FILTER TABS ── */
.filter-bar {
  max-width: 960px;
  margin: 0 auto;
  padding: 2rem 2rem 0;
  display: flex;
  gap: 0.375rem;
  flex-wrap: wrap;
}

.filter-btn {
  font-family: var(--font-head);
  font-size: 0.75rem;
  font-weight: 600;
  padding: 0.375rem 0.875rem;
  border: 1px solid var(--border);
  border-radius: 4px;
  background: transparent;
  color: var(--text-muted);
  cursor: pointer;
  transition: all 0.15s;
  letter-spacing: 0.01em;
}

.filter-btn:hover {
  background: var(--bg-subtle);
  color: var(--text);
  border-color: #D0D0D0;
}

.filter-btn.active {
  background: var(--text);
  color: #fff;
  border-color: var(--text);
}

/* ── POSTS GRID ── */
.posts-grid {
  max-width: 960px;
  margin: 2rem auto 0;
  padding: 0 2rem 6rem;
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(400px, 1fr));
  gap: 0;
  border: 1px solid var(--border);
  background: var(--border);
}

.post-card {
  background: var(--bg);
  padding: 2rem;
  display: flex;
  flex-direction: column;
  gap: 0.875rem;
  transition: background 0.15s;
  cursor: pointer;
}

.post-card:hover { background: var(--bg-subtle); }

.post-tag {
  display: inline-flex;
  align-items: center;
  gap: 0.3rem;
  font-size: 0.6875rem;
  font-weight: 700;
  letter-spacing: 0.1em;
  text-transform: uppercase;
  color: var(--tag-text);
  background: var(--tag-bg);
  padding: 0.2rem 0.55rem;
  border-radius: 3px;
  width: fit-content;
}

.post-card h2 {
  font-family: var(--font-head);
  font-size: 1.1875rem;
  font-weight: 800;
  letter-spacing: -0.025em;
  line-height: 1.25;
  color: var(--text);
}

.post-card p {
  font-size: 0.9375rem;
  color: var(--text-muted);
  line-height: 1.65;
  flex: 1;
}

.post-meta {
  display: flex;
  align-items: center;
  gap: 0.625rem;
  padding-top: 0.75rem;
  border-top: 1px solid var(--border);
}

.post-avatar {
  width: 26px;
  height: 26px;
  border-radius: 50%;
  background: var(--green-dark);
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 0.6rem;
  font-weight: 800;
  color: #fff;
  flex-shrink: 0;
  letter-spacing: 0;
}

.post-meta-info {
  display: flex;
  flex-direction: column;
  gap: 0.05rem;
}

.post-author {
  font-size: 0.8125rem;
  font-weight: 600;
  color: var(--text);
}

.post-date {
  font-size: 0.75rem;
  color: var(--text-light);
}

.post-read {
  margin-left: auto;
  font-size: 0.75rem;
  color: var(--text-light);
  white-space: nowrap;
}

/* ── FEATURED POST ── */
.post-card.featured {
  grid-column: 1 / -1;
  flex-direction: row;
  gap: 3rem;
  align-items: flex-start;
  padding: 2.5rem;
  background: var(--bg);
}

.post-card.featured:hover { background: var(--bg-subtle); }

.post-card.featured .post-content {
  flex: 1;
  display: flex;
  flex-direction: column;
  gap: 0.875rem;
}

.post-card.featured h2 {
  font-size: 1.625rem;
  letter-spacing: -0.03em;
}

.featured-badge {
  font-size: 0.6875rem;
  font-weight: 700;
  letter-spacing: 0.12em;
  text-transform: uppercase;
  color: var(--green-dark);
  margin-bottom: 0.125rem;
}

/* ── AUTHOR STRIP ── */
.author-strip {
  background: var(--text);
  color: #fff;
  padding: 3rem 2rem;
}

.author-strip-inner {
  max-width: 960px;
  margin: 0 auto;
  display: flex;
  align-items: center;
  gap: 2rem;
}

.author-avatar-lg {
  width: 56px;
  height: 56px;
  border-radius: 50%;
  background: var(--green-dark);
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 1.125rem;
  font-weight: 800;
  flex-shrink: 0;
}

.author-info h3 {
  font-size: 0.9375rem;
  font-weight: 700;
  margin-bottom: 0.25rem;
  letter-spacing: -0.01em;
}

.author-info p {
  font-size: 0.875rem;
  color: rgba(255,255,255,0.55);
  line-height: 1.55;
}

/* ── FOOTER ── */
.footer {
  border-top: 1px solid var(--border);
  padding: 1.75rem 2rem;
  max-width: 960px;
  margin: 0 auto;
  display: flex;
  justify-content: space-between;
  align-items: center;
  flex-wrap: wrap;
  gap: 1rem;
}

.footer-copy {
  font-size: 0.8125rem;
  color: var(--text-light);
}

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

.footer-links a {
  font-size: 0.8125rem;
  color: var(--text-muted);
  transition: color 0.15s;
}

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

/* ── SINGLE POST PAGE ── */
.post-header {
  max-width: 720px;
  margin: 0 auto;
  padding: 4rem 2rem 2.5rem;
}

.post-header .post-tag { margin-bottom: 1.5rem; }

.post-header h1 {
  font-family: var(--font-head);
  font-size: clamp(2rem, 5vw, 3.25rem);
  font-weight: 900;
  letter-spacing: -0.035em;
  line-height: 1.05;
  margin-bottom: 1.5rem;
  color: var(--text);
}

.post-header .lead {
  font-size: 1.125rem;
  color: var(--text-muted);
  line-height: 1.7;
  margin-bottom: 2rem;
  font-weight: 400;
}

.post-header .post-meta {
  border-top: 1px solid var(--border);
  padding-top: 1.5rem;
}

.post-body {
  max-width: 720px;
  margin: 0 auto;
  padding: 3rem 2rem 6rem;
}

.post-body h2 {
  font-family: var(--font-head);
  font-size: 1.5rem;
  font-weight: 800;
  letter-spacing: -0.025em;
  margin: 2.5rem 0 1rem;
  color: var(--text);
}

.post-body h3 {
  font-family: var(--font-head);
  font-size: 1.125rem;
  font-weight: 700;
  letter-spacing: -0.01em;
  margin: 2rem 0 0.75rem;
  color: var(--text);
}

.post-body p {
  font-size: 1.0625rem;
  line-height: 1.8;
  color: #3A3A3A;
  margin-bottom: 1.25rem;
}

.post-body ul, .post-body ol {
  padding-left: 1.5rem;
  margin-bottom: 1.25rem;
}

.post-body li {
  font-size: 1.0625rem;
  line-height: 1.8;
  color: #3A3A3A;
  margin-bottom: 0.5rem;
}

.post-body blockquote {
  border-left: 2px solid var(--green);
  padding: 0.75rem 0 0.75rem 1.5rem;
  margin: 2rem 0;
  font-size: 1.0625rem;
  font-style: italic;
  color: var(--text-muted);
}

.post-body .divider {
  border: none;
  border-top: 1px solid var(--border);
  margin: 3rem 0;
}

/* ── RESPONSIVE ── */
@media (max-width: 640px) {
  .nav-links { display: none; }
  .posts-grid { grid-template-columns: 1fr; padding: 0 0 4rem; }
  .post-card.featured { flex-direction: column; gap: 1.25rem; }
  .author-strip-inner { flex-direction: column; text-align: center; }
  .footer { flex-direction: column; text-align: center; }
  .hero { padding: 3rem 1.5rem 2.5rem; }
}