*, *::before, *::after { box-sizing: border-box; margin: 0; padding: 0; }

:root {
  --black: #0a0a0a;
  --white: #ffffff;
  --gray-50: #fafafa;
  --gray-100: #f4f4f4;
  --gray-200: #e8e8e8;
  --gray-400: #a0a0a0;
  --gray-600: #606060;
  --gray-800: #1a1a1a;
  --accent: #7C5CFC;
  --accent-light: #a78bfa;
  --accent-muted: #ede9fe;
  --radius: 16px;
  --radius-sm: 8px;
  --transition: 0.35s cubic-bezier(0.4, 0, 0.2, 1);
}

html { scroll-behavior: smooth; }
body {
  font-family: 'Inter', sans-serif;
  background: var(--white);
  color: var(--black);
  line-height: 1.6;
  overflow-x: hidden;
}

/* ── NAV ────────────────────────────────────────────── */
nav {
  position: fixed; top: 0; left: 0; right: 0; z-index: 100;
  display: flex; align-items: center; justify-content: space-between;
  padding: 20px 60px;
  background: rgba(255,255,255,0.92);
  backdrop-filter: blur(18px);
  border-bottom: 1px solid var(--gray-200);
}
.logo { font-size: 1.35rem; font-weight: 800; letter-spacing: -0.5px; color: var(--black); text-decoration: none; }
.logo span { color: var(--accent); }
.nav-links { display: flex; align-items: center; gap: 36px; list-style: none; }
.nav-links a { font-size: 0.875rem; font-weight: 500; color: var(--gray-600); text-decoration: none; transition: color var(--transition); }
.nav-links a:hover { color: var(--black); }
.nav-cta { background: var(--black); color: var(--white) !important; padding: 10px 22px; border-radius: 100px; font-weight: 600 !important; transition: background var(--transition), transform var(--transition) !important; }
.nav-cta:hover { background: var(--accent) !important; transform: translateY(-1px); color: var(--white) !important; }

/* ── PAGE HEADER ─────────────────────────────────────── */
.page-header {
  padding: 160px 60px 80px;
  background: var(--gray-50);
  text-align: center;
  position: relative;
  overflow: hidden;
}
.page-header::before {
  content: '';
  position: absolute;
  top: -150px; left: 50%; transform: translateX(-50%);
  width: 700px; height: 700px;
  background: radial-gradient(circle, rgba(124,92,252,0.07) 0%, transparent 70%);
  pointer-events: none;
}
.page-label {
  display: inline-block;
  font-size: 0.75rem; font-weight: 700; letter-spacing: 2px; text-transform: uppercase;
  color: var(--accent); background: var(--accent-muted);
  padding: 6px 16px; border-radius: 100px; margin-bottom: 24px;
}
.page-header h1 {
  font-size: clamp(2.8rem, 6vw, 5rem);
  font-weight: 900; letter-spacing: -3px; line-height: 1.0;
  color: var(--black); margin-bottom: 20px;
}
.page-header p {
  font-size: 1.05rem; color: var(--gray-600);
  max-width: 520px; margin: 0 auto; line-height: 1.75;
}

/* ── BLOG LAYOUT ──────────────────────────────────────── */
.blog-layout {
  display: grid;
  grid-template-columns: 320px 1fr;
  min-height: calc(100vh - 300px);
  border-top: 1px solid var(--gray-200);
}

/* ── SIDEBAR ──────────────────────────────────────────── */
.blog-sidebar {
  background: var(--gray-50);
  border-right: 1px solid var(--gray-200);
  padding: 40px 0;
  position: sticky;
  top: 81px;
  height: calc(100vh - 81px);
  overflow-y: auto;
  scrollbar-width: thin;
  scrollbar-color: var(--gray-200) transparent;
}
.blog-sidebar::-webkit-scrollbar { width: 4px; }
.blog-sidebar::-webkit-scrollbar-thumb { background: var(--gray-200); border-radius: 2px; }

.sidebar-label {
  font-size: 0.65rem;
  font-weight: 800;
  letter-spacing: 2.5px;
  text-transform: uppercase;
  color: var(--gray-400);
  padding: 0 28px;
  margin-bottom: 16px;
}

.post-link {
  display: flex;
  flex-direction: column;
  gap: 6px;
  width: 100%;
  background: none;
  border: none;
  border-left: 3px solid transparent;
  padding: 18px 28px;
  text-align: left;
  cursor: pointer;
  transition: all var(--transition);
  position: relative;
}
.post-link:hover {
  background: var(--white);
  border-left-color: var(--gray-200);
}
.post-link.active {
  background: var(--white);
  border-left-color: var(--accent);
}

.post-link-meta {
  font-size: 0.68rem;
  font-weight: 600;
  letter-spacing: 0.5px;
  color: var(--gray-400);
  text-transform: uppercase;
}
.post-link.active .post-link-meta { color: var(--accent); }

.post-link-title {
  font-size: 0.875rem;
  font-weight: 700;
  color: var(--gray-600);
  line-height: 1.45;
  letter-spacing: -0.1px;
  transition: color var(--transition);
}
.post-link:hover .post-link-title,
.post-link.active .post-link-title { color: var(--black); }

.post-link-tags {
  display: flex;
  flex-wrap: wrap;
  gap: 5px;
  margin-top: 2px;
}
.ptag {
  font-size: 0.62rem;
  font-weight: 700;
  letter-spacing: 0.5px;
  text-transform: uppercase;
  color: var(--accent);
  background: var(--accent-muted);
  padding: 2px 8px;
  border-radius: 100px;
}

/* ── ARTICLE READER ───────────────────────────────────── */
.blog-reader {
  padding: 60px 80px;
  min-width: 0;
  background: var(--white);
}

.blog-post {
  display: none;
  max-width: 760px;
  animation: fadeIn 0.4s ease;
}
.blog-post.active {
  display: block;
}

@keyframes fadeIn {
  from { opacity: 0; transform: translateY(10px); }
  to   { opacity: 1; transform: translateY(0); }
}

/* POST HEADER */
.post-header {
  margin-bottom: 44px;
  padding-bottom: 44px;
  border-bottom: 1px solid var(--gray-200);
}
.post-tags {
  display: flex;
  gap: 8px;
  margin-bottom: 20px;
}
.atag {
  font-size: 0.72rem;
  font-weight: 700;
  letter-spacing: 1px;
  text-transform: uppercase;
  color: var(--accent);
  background: var(--accent-muted);
  padding: 4px 14px;
  border-radius: 100px;
}
.post-title {
  font-size: clamp(1.8rem, 3.5vw, 2.8rem);
  font-weight: 900;
  letter-spacing: -1.5px;
  line-height: 1.08;
  color: var(--black);
  margin-bottom: 20px;
}
.post-meta {
  display: flex;
  align-items: center;
  gap: 10px;
  font-size: 0.825rem;
  color: var(--gray-400);
  font-weight: 500;
  flex-wrap: wrap;
}
.meta-dot {
  width: 4px; height: 4px;
  border-radius: 50%;
  background: var(--gray-300, #d1d5db);
  flex-shrink: 0;
}

/* POST BODY */
.post-body {
  font-size: 1rem;
  line-height: 1.85;
  color: var(--gray-600);
}
.post-lead {
  font-size: 1.15rem;
  line-height: 1.75;
  color: var(--black);
  font-weight: 400;
  margin-bottom: 40px;
}
.post-body h2 {
  font-size: 1.35rem;
  font-weight: 800;
  color: var(--black);
  letter-spacing: -0.5px;
  margin: 40px 0 16px;
  line-height: 1.2;
}
.post-body p { margin-bottom: 20px; }
.post-body ul {
  margin: 0 0 24px 0;
  padding: 0;
  list-style: none;
  display: flex;
  flex-direction: column;
  gap: 14px;
}
.post-body ul li {
  padding-left: 20px;
  position: relative;
  font-size: 0.95rem;
  line-height: 1.75;
}
.post-body ul li::before {
  content: '';
  position: absolute;
  left: 0; top: 10px;
  width: 6px; height: 6px;
  border-radius: 50%;
  background: var(--accent);
}
.post-body ul li strong { color: var(--black); font-weight: 700; }

/* POST CTA */
.post-cta {
  margin-top: 56px;
  padding: 40px;
  background: var(--gray-50);
  border: 1px solid var(--gray-200);
  border-radius: var(--radius);
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 24px;
  flex-wrap: wrap;
}
.post-cta p {
  font-size: 1rem;
  font-weight: 600;
  color: var(--black);
  margin: 0;
  line-height: 1.4;
}
.btn-primary {
  display: inline-block;
  background: var(--black);
  color: var(--white);
  padding: 12px 26px;
  border-radius: 100px;
  font-size: 0.875rem;
  font-weight: 600;
  text-decoration: none;
  white-space: nowrap;
  transition: all var(--transition);
  flex-shrink: 0;
}
.btn-primary:hover { background: var(--accent); transform: translateY(-2px); }

/* ── FOOTER ────────────────────────────────────────────── */
footer { background: var(--black); padding: 60px 60px 40px; }
.footer-inner { display: flex; justify-content: space-between; align-items: center; gap: 24px; flex-wrap: wrap; }
.footer-logo { font-size: 1.2rem; font-weight: 800; color: var(--white); text-decoration: none; }
.footer-logo span { color: var(--accent-light); }
.footer-links { display: flex; gap: 28px; list-style: none; }
.footer-links a { font-size: 0.875rem; color: rgba(255,255,255,0.45); text-decoration: none; transition: color var(--transition); }
.footer-links a:hover { color: var(--white); }
.footer-copy { font-size: 0.8rem; color: rgba(255,255,255,0.25); }

/* ── RESPONSIVE ──────────────────────────────────────── */
@media (max-width: 1024px) {
  .blog-layout { grid-template-columns: 260px 1fr; }
  .blog-reader { padding: 48px 40px; }
}
@media (max-width: 768px) {
  nav { padding: 16px 20px; }
  .nav-links { display: none; }
  .page-header { padding: 120px 24px 60px; }
  .blog-layout {
    grid-template-columns: 1fr;
  }
  .blog-sidebar {
    position: static;
    height: auto;
    border-right: none;
    border-bottom: 1px solid var(--gray-200);
    padding: 24px 0;
    overflow-x: auto;
    display: flex;
    flex-direction: column;
  }
  .blog-reader { padding: 32px 20px; }
  .post-cta { flex-direction: column; align-items: flex-start; }
  footer { padding: 40px 20px 28px; }
  .footer-inner { flex-direction: column; align-items: flex-start; gap: 20px; }
  .footer-links { flex-wrap: wrap; gap: 16px; }
}