/* ============================================================
   TELECOM DEMYSTIFIED — Main Stylesheet
   Author: Shashi Bhushan Jha
   ============================================================ */

/* ---------- CSS Variables ---------- */
:root {
  --bg-primary:    #060d1a;
  --bg-secondary:  #0c1628;
  --bg-card:       #0f1f36;
  --bg-card-hover: #152845;
  --border:        #1e3a5f;
  --accent:        #00c9c9;
  --accent-dim:    #00909090;
  --accent-glow:   rgba(0, 201, 201, 0.15);
  --accent2:       #7c3aed;
  --accent2-glow:  rgba(124, 58, 237, 0.12);
  --text-primary:  #e8f0fe;
  --text-secondary:#8ba4c2;
  --text-muted:    #4d6a8a;
  --tag-5g:        #00c9c9;
  --tag-iot:       #22c55e;
  --tag-ipr:       #a855f7;
  --radius-sm:     6px;
  --radius:        12px;
  --radius-lg:     20px;
  --font-sans:     'Inter', 'Segoe UI', system-ui, sans-serif;
  --font-mono:     'JetBrains Mono', 'Fira Code', 'Cascadia Code', monospace;
  --shadow:        0 4px 24px rgba(0,0,0,0.4);
  --shadow-lg:     0 8px 48px rgba(0,0,0,0.6);
  --transition:    0.25s cubic-bezier(0.4, 0, 0.2, 1);
}

/* ---------- Reset ---------- */
*, *::before, *::after { box-sizing: border-box; margin: 0; padding: 0; }
html { scroll-behavior: smooth; font-size: 16px; }
body {
  font-family: var(--font-sans);
  background: var(--bg-primary);
  color: var(--text-primary);
  line-height: 1.7;
  overflow-x: hidden;
}
a { color: var(--accent); text-decoration: none; transition: color var(--transition); }
a:hover { color: #fff; }
img { max-width: 100%; display: block; }
ul { list-style: none; }

/* ---------- Scrollbar ---------- */
::-webkit-scrollbar { width: 6px; }
::-webkit-scrollbar-track { background: var(--bg-primary); }
::-webkit-scrollbar-thumb { background: var(--border); border-radius: 99px; }
::-webkit-scrollbar-thumb:hover { background: var(--accent-dim); }

/* ---------- Typography ---------- */
h1, h2, h3, h4, h5, h6 {
  font-weight: 700;
  line-height: 1.25;
  color: var(--text-primary);
}
h1 { font-size: clamp(2rem, 5vw, 3.5rem); }
h2 { font-size: clamp(1.5rem, 3.5vw, 2.25rem); }
h3 { font-size: clamp(1.15rem, 2.5vw, 1.5rem); }
p { color: var(--text-secondary); margin-bottom: 1rem; }
p:last-child { margin-bottom: 0; }

/* ---------- Utility ---------- */
.container { max-width: 1200px; margin: 0 auto; padding: 0 1.5rem; }
.container--narrow { max-width: 800px; margin: 0 auto; padding: 0 1.5rem; }
.section { padding: 5rem 0; }
.section--sm { padding: 3rem 0; }
.text-accent { color: var(--accent); }
.text-muted { color: var(--text-muted); font-size: 0.875rem; }
.visually-hidden { position: absolute; width: 1px; height: 1px; clip: rect(0,0,0,0); overflow: hidden; }

/* ---------- Gradient Text ---------- */
.gradient-text {
  background: linear-gradient(135deg, var(--accent) 0%, #7c3aed 100%);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
}

/* ---------- Buttons ---------- */
.btn {
  display: inline-flex;
  align-items: center;
  gap: 0.5rem;
  padding: 0.65rem 1.4rem;
  border-radius: var(--radius-sm);
  font-family: var(--font-sans);
  font-size: 0.9rem;
  font-weight: 600;
  cursor: pointer;
  border: none;
  transition: all var(--transition);
  white-space: nowrap;
}
.btn--primary {
  background: var(--accent);
  color: #000;
}
.btn--primary:hover { background: #fff; color: #000; transform: translateY(-2px); box-shadow: 0 6px 20px var(--accent-glow); }
.btn--outline {
  background: transparent;
  color: var(--accent);
  border: 1.5px solid var(--accent);
}
.btn--outline:hover { background: var(--accent); color: #000; transform: translateY(-2px); }
.btn--ghost {
  background: var(--bg-card);
  color: var(--text-secondary);
  border: 1px solid var(--border);
}
.btn--ghost:hover { background: var(--bg-card-hover); color: var(--text-primary); border-color: var(--accent-dim); }

/* ---------- Tags / Badges ---------- */
.tag {
  display: inline-flex;
  align-items: center;
  gap: 0.3rem;
  padding: 0.25rem 0.75rem;
  border-radius: 99px;
  font-size: 0.78rem;
  font-weight: 600;
  text-transform: uppercase;
  letter-spacing: 0.04em;
}
.tag--5g    { background: rgba(0,201,201,0.12); color: var(--tag-5g); border: 1px solid rgba(0,201,201,0.25); }
.tag--iot   { background: rgba(34,197,94,0.12);  color: var(--tag-iot);  border: 1px solid rgba(34,197,94,0.25); }
.tag--ipr   { background: rgba(168,85,247,0.12); color: var(--tag-ipr);  border: 1px solid rgba(168,85,247,0.25); }
.tag--general { background: rgba(139,164,194,0.1); color: var(--text-secondary); border: 1px solid var(--border); }

/* ============================================================
   NAVIGATION
   ============================================================ */
.nav {
  position: fixed;
  top: 0; left: 0; right: 0;
  z-index: 1000;
  transition: background var(--transition), border-color var(--transition), backdrop-filter var(--transition);
  border-bottom: 1px solid transparent;
}
.nav.scrolled {
  background: rgba(6, 13, 26, 0.92);
  -webkit-backdrop-filter: blur(20px);
  backdrop-filter: blur(20px);
  border-bottom-color: var(--border);
}
.nav__inner {
  display: flex;
  align-items: center;
  justify-content: space-between;
  height: 4rem;
  max-width: 1200px;
  margin: 0 auto;
  padding: 0 1.5rem;
}
.nav__logo {
  display: flex;
  align-items: center;
  gap: 0.6rem;
  font-size: 1.1rem;
  font-weight: 800;
  color: var(--text-primary);
}
.nav__logo-icon {
  width: 34px;
  height: 34px;
  background: linear-gradient(135deg, var(--accent), var(--accent2));
  border-radius: var(--radius-sm);
  display: grid;
  place-items: center;
  font-size: 1rem;
}
.nav__logo span { color: var(--accent); }
.nav__links {
  display: flex;
  align-items: center;
  gap: 0.25rem;
}
.nav__links a {
  padding: 0.4rem 0.85rem;
  border-radius: var(--radius-sm);
  color: var(--text-secondary);
  font-size: 0.9rem;
  font-weight: 500;
  transition: all var(--transition);
}
.nav__links a:hover, .nav__links a.active {
  color: var(--text-primary);
  background: var(--bg-card);
}
.nav__links a.active { color: var(--accent); }
.nav__cta { display: flex; align-items: center; gap: 0.75rem; }
.nav__hamburger {
  display: none;
  flex-direction: column;
  gap: 5px;
  cursor: pointer;
  padding: 4px;
  background: none;
  border: none;
  color: var(--text-primary);
}
.nav__hamburger span {
  display: block;
  width: 22px;
  height: 2px;
  background: currentColor;
  border-radius: 99px;
  transition: all var(--transition);
}

/* ---------- Mobile Nav ---------- */
.nav__mobile {
  display: none;
  position: fixed;
  top: 4rem; left: 0; right: 0; bottom: 0;
  background: var(--bg-primary);
  padding: 1.5rem;
  flex-direction: column;
  gap: 0.5rem;
  border-top: 1px solid var(--border);
  overflow-y: auto;
  z-index: 999;
}
.nav__mobile.open { display: flex; }
.nav__mobile a {
  padding: 0.85rem 1rem;
  border-radius: var(--radius-sm);
  color: var(--text-secondary);
  font-size: 1rem;
  font-weight: 500;
  border: 1px solid var(--border);
  transition: all var(--transition);
}
.nav__mobile a:hover { background: var(--bg-card); color: var(--text-primary); border-color: var(--accent-dim); }

/* ============================================================
   HERO
   ============================================================ */
.hero {
  position: relative;
  min-height: 100vh;
  display: flex;
  align-items: center;
  overflow: hidden;
  padding-top: 4rem;
}
.hero__bg {
  position: absolute;
  inset: 0;
  pointer-events: none;
}
.hero__grid {
  position: absolute;
  inset: 0;
  background-image:
    linear-gradient(var(--border) 1px, transparent 1px),
    linear-gradient(90deg, var(--border) 1px, transparent 1px);
  background-size: 60px 60px;
  opacity: 0.35;
  -webkit-mask-image: radial-gradient(ellipse 80% 80% at 50% 50%, black 0%, transparent 100%);
  mask-image: radial-gradient(ellipse 80% 80% at 50% 50%, black 0%, transparent 100%);
}
.hero__glow1 {
  position: absolute;
  width: 700px; height: 700px;
  top: -200px; left: -200px;
  background: radial-gradient(circle, rgba(0,201,201,0.12) 0%, transparent 70%);
  border-radius: 50%;
}
.hero__glow2 {
  position: absolute;
  width: 500px; height: 500px;
  bottom: -100px; right: -100px;
  background: radial-gradient(circle, rgba(124,58,237,0.1) 0%, transparent 70%);
  border-radius: 50%;
}
.hero__content {
  position: relative;
  z-index: 1;
  max-width: 1200px;
  margin: 0 auto;
  padding: 0 1.5rem;
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 4rem;
  align-items: center;
}
.hero__badge {
  display: inline-flex;
  align-items: center;
  gap: 0.5rem;
  padding: 0.35rem 1rem;
  background: var(--accent-glow);
  border: 1px solid rgba(0,201,201,0.25);
  border-radius: 99px;
  font-size: 0.8rem;
  font-weight: 600;
  color: var(--accent);
  letter-spacing: 0.05em;
  text-transform: uppercase;
  margin-bottom: 1.25rem;
}
.hero__badge-dot {
  width: 7px; height: 7px;
  background: var(--accent);
  border-radius: 50%;
  animation: pulse 2s ease infinite;
}
@keyframes pulse {
  0%, 100% { opacity: 1; transform: scale(1); }
  50%       { opacity: 0.5; transform: scale(1.5); }
}
.hero__title { margin-bottom: 1.25rem; }
.hero__title em { font-style: normal; }
.hero__desc { font-size: 1.05rem; margin-bottom: 2rem; max-width: 520px; }
.hero__actions { display: flex; gap: 1rem; flex-wrap: wrap; }
.hero__stats {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 1rem;
  margin-top: 2.5rem;
  padding-top: 2rem;
  border-top: 1px solid var(--border);
}
.hero__stat-value {
  font-size: 1.75rem;
  font-weight: 800;
  color: var(--accent);
  display: block;
}
.hero__stat-label {
  font-size: 0.8rem;
  color: var(--text-muted);
  text-transform: uppercase;
  letter-spacing: 0.05em;
}
.hero__visual {
  position: relative;
  display: flex;
  justify-content: center;
  align-items: center;
}
.hero__terminal {
  background: var(--bg-card);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  width: 100%;
  max-width: 460px;
  overflow: hidden;
  box-shadow: var(--shadow-lg);
}
.hero__terminal-bar {
  padding: 0.75rem 1rem;
  background: var(--bg-secondary);
  border-bottom: 1px solid var(--border);
  display: flex;
  align-items: center;
  gap: 0.5rem;
}
.hero__terminal-dot {
  width: 11px; height: 11px; border-radius: 50%;
}
.hero__terminal-dot:nth-child(1) { background: #ff5f57; }
.hero__terminal-dot:nth-child(2) { background: #febc2e; }
.hero__terminal-dot:nth-child(3) { background: #28c840; }
.hero__terminal-title {
  margin-left: auto;
  margin-right: auto;
  font-size: 0.78rem;
  color: var(--text-muted);
  font-family: var(--font-mono);
}
.hero__terminal-body {
  padding: 1.25rem;
  font-family: var(--font-mono);
  font-size: 0.82rem;
  line-height: 1.8;
}
.terminal-line { display: flex; }
.terminal-prompt { color: var(--accent); margin-right: 0.75rem; -webkit-user-select: none; user-select: none; }
.terminal-cmd { color: #e8f0fe; }
.terminal-comment { color: var(--text-muted); }
.terminal-output { color: #22c55e; padding-left: 1.5rem; }
.terminal-cursor {
  display: inline-block;
  width: 8px; height: 14px;
  background: var(--accent);
  animation: blink 1s step-end infinite;
  vertical-align: middle;
  margin-left: 2px;
}
@keyframes blink { 0%, 100% { opacity: 1; } 50% { opacity: 0; } }

/* ============================================================
   CATEGORIES SECTION
   ============================================================ */
.categories { padding: 5rem 0; }
.section-header {
  text-align: center;
  margin-bottom: 3rem;
}
.section-header__pretitle {
  display: inline-block;
  font-size: 0.8rem;
  font-weight: 700;
  letter-spacing: 0.12em;
  text-transform: uppercase;
  color: var(--accent);
  margin-bottom: 0.75rem;
}
.section-header__title { margin-bottom: 0.75rem; }
.section-header__desc { color: var(--text-secondary); max-width: 540px; margin: 0 auto; }
.categories__grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 1.5rem;
}
.cat-card {
  background: var(--bg-card);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 2rem 1.75rem;
  transition: all var(--transition);
  position: relative;
  overflow: hidden;
  cursor: pointer;
}
.cat-card::before {
  content: '';
  position: absolute;
  top: 0; left: 0; right: 0;
  height: 3px;
  border-radius: var(--radius) var(--radius) 0 0;
  opacity: 0;
  transition: opacity var(--transition);
}
.cat-card:hover { background: var(--bg-card-hover); border-color: transparent; transform: translateY(-4px); box-shadow: var(--shadow-lg); }
.cat-card--5g::before  { background: linear-gradient(90deg, var(--tag-5g), transparent); }
.cat-card--iot::before { background: linear-gradient(90deg, var(--tag-iot), transparent); }
.cat-card--ipr::before { background: linear-gradient(90deg, var(--tag-ipr), transparent); }
.cat-card:hover::before { opacity: 1; }
.cat-card__icon {
  font-size: 2.25rem;
  margin-bottom: 1rem;
  display: block;
}
.cat-card__title { font-size: 1.15rem; margin-bottom: 0.6rem; }
.cat-card__desc { font-size: 0.9rem; color: var(--text-secondary); margin-bottom: 1.25rem; }
.cat-card__count { font-size: 0.8rem; color: var(--text-muted); }
.cat-card__link {
  display: inline-flex;
  align-items: center;
  gap: 0.4rem;
  font-size: 0.85rem;
  font-weight: 600;
  margin-top: 0.75rem;
}
.cat-card--5g  .cat-card__link { color: var(--tag-5g); }
.cat-card--iot .cat-card__link { color: var(--tag-iot); }
.cat-card--ipr .cat-card__link { color: var(--tag-ipr); }

/* ============================================================
   FEATURED POSTS GRID
   ============================================================ */
.posts-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(340px, 1fr));
  gap: 1.5rem;
}
.posts-grid--featured {
  grid-template-columns: 1fr 1fr;
  grid-template-rows: auto auto;
}
.posts-grid--featured .post-card:first-child {
  grid-column: 1 / -1;
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 0;
}
.post-card {
  background: var(--bg-card);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  overflow: hidden;
  transition: all var(--transition);
  display: flex;
  flex-direction: column;
}
.post-card:hover { background: var(--bg-card-hover); border-color: var(--accent-dim); transform: translateY(-4px); box-shadow: var(--shadow-lg); }
.post-card__cover {
  height: 220px;
  overflow: hidden;
  position: relative;
  flex-shrink: 0;
}
.post-card__cover-inner {
  width: 100%;
  height: 100%;
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 4rem;
  transition: transform var(--transition);
}
.post-card:hover .post-card__cover-inner { transform: scale(1.05); }
.cover--5g  { background: linear-gradient(135deg, #021a1a, #003333); }
.cover--iot { background: linear-gradient(135deg, #021a0e, #003316); }
.cover--ipr { background: linear-gradient(135deg, #12031a, #1e0033); }
.post-card__body { padding: 1.5rem; flex: 1; display: flex; flex-direction: column; }
.post-card__meta {
  display: flex;
  align-items: center;
  gap: 0.75rem;
  margin-bottom: 0.875rem;
  flex-wrap: wrap;
}
.post-card__date, .post-card__read { font-size: 0.78rem; color: var(--text-muted); }
.post-card__title { font-size: 1.15rem; margin-bottom: 0.6rem; line-height: 1.4; }
.post-card__title a { color: var(--text-primary); }
.post-card__title a:hover { color: var(--accent); }
.post-card__excerpt { font-size: 0.88rem; color: var(--text-secondary); flex: 1; margin-bottom: 1.25rem; }
.post-card__footer {
  display: flex;
  align-items: center;
  justify-content: space-between;
  border-top: 1px solid var(--border);
  padding-top: 1rem;
  margin-top: auto;
}
.post-card__author { display: flex; align-items: center; gap: 0.6rem; }
.post-card__avatar {
  width: 30px; height: 30px;
  border-radius: 50%;
  background: linear-gradient(135deg, var(--accent), var(--accent2));
  display: grid;
  place-items: center;
  font-size: 0.75rem;
  font-weight: 700;
  color: #fff;
  flex-shrink: 0;
}
.post-card__author-name { font-size: 0.8rem; color: var(--text-secondary); font-weight: 500; }
.post-card__arrow { font-size: 1rem; color: var(--text-muted); transition: all var(--transition); }
.post-card:hover .post-card__arrow { color: var(--accent); transform: translateX(3px); }

/* Featured first post overrides */
.posts-grid--featured .post-card:first-child .post-card__cover { height: 100%; min-height: 280px; }
.posts-grid--featured .post-card:first-child .post-card__body { padding: 2rem; }
.posts-grid--featured .post-card:first-child .post-card__title { font-size: 1.5rem; }

/* ============================================================
   NEWSLETTER
   ============================================================ */
.newsletter {
  background: linear-gradient(135deg, var(--bg-card) 0%, var(--bg-secondary) 100%);
  border: 1px solid var(--border);
  border-radius: var(--radius-lg);
  padding: 3.5rem;
  text-align: center;
  position: relative;
  overflow: hidden;
}
.newsletter::before {
  content:'';
  position: absolute;
  width: 400px; height: 400px;
  background: radial-gradient(circle, rgba(0,201,201,0.08) 0%, transparent 70%);
  top: -100px; left: 50%; transform: translateX(-50%);
  pointer-events: none;
}
.newsletter__title { font-size: 1.75rem; margin-bottom: 0.75rem; }
.newsletter__desc { color: var(--text-secondary); max-width: 480px; margin: 0 auto 2rem; }
.newsletter__form { display: flex; gap: 0.75rem; max-width: 460px; margin: 0 auto; }
.newsletter__input {
  flex: 1;
  padding: 0.7rem 1rem;
  background: var(--bg-primary);
  border: 1.5px solid var(--border);
  border-radius: var(--radius-sm);
  color: var(--text-primary);
  font-family: var(--font-sans);
  font-size: 0.9rem;
  outline: none;
  transition: border-color var(--transition);
}
.newsletter__input::placeholder { color: var(--text-muted); }
.newsletter__input:focus { border-color: var(--accent); }
.newsletter__note { font-size: 0.78rem; color: var(--text-muted); margin-top: 0.75rem; }

/* ============================================================
   BLOG PAGE
   ============================================================ */
.blog-header {
  padding: 7rem 0 3rem;
  text-align: center;
  position: relative;
}
.blog-header__title { margin-bottom: 0.75rem; }
.blog-header__desc { color: var(--text-secondary); max-width: 560px; margin: 0 auto; }
.blog-filters {
  display: flex;
  align-items: center;
  gap: 0.5rem;
  flex-wrap: wrap;
  margin-bottom: 2.5rem;
}
.filter-btn {
  padding: 0.45rem 1.1rem;
  border-radius: 99px;
  border: 1.5px solid var(--border);
  background: transparent;
  color: var(--text-secondary);
  font-size: 0.85rem;
  font-weight: 500;
  cursor: pointer;
  transition: all var(--transition);
  font-family: var(--font-sans);
}
.filter-btn:hover { border-color: var(--accent-dim); color: var(--text-primary); }
.filter-btn.active { background: var(--accent); border-color: var(--accent); color: #000; font-weight: 700; }
.search-box {
  margin-left: auto;
  position: relative;
}
.search-box__input {
  padding: 0.45rem 1rem 0.45rem 2.25rem;
  background: var(--bg-card);
  border: 1.5px solid var(--border);
  border-radius: 99px;
  color: var(--text-primary);
  font-size: 0.85rem;
  font-family: var(--font-sans);
  outline: none;
  width: 220px;
  transition: all var(--transition);
}
.search-box__input:focus { border-color: var(--accent); width: 280px; }
.search-box__icon {
  position: absolute;
  left: 0.75rem; top: 50%;
  transform: translateY(-50%);
  color: var(--text-muted);
  font-size: 0.85rem;
  pointer-events: none;
}

/* ============================================================
   ARTICLE PAGE
   ============================================================ */
.article-hero {
  padding: 7rem 0 3rem;
  position: relative;
}
.article-hero__breadcrumb {
  display: flex;
  align-items: center;
  gap: 0.5rem;
  font-size: 0.82rem;
  color: var(--text-muted);
  margin-bottom: 1.5rem;
}
.article-hero__breadcrumb a { color: var(--text-muted); }
.article-hero__breadcrumb a:hover { color: var(--accent); }
.article-hero__meta {
  display: flex;
  align-items: center;
  gap: 1rem;
  flex-wrap: wrap;
  margin-bottom: 1.25rem;
}
.article-hero__title { margin-bottom: 1rem; }
.article-hero__subtitle { font-size: 1.1rem; line-height: 1.6; color: var(--text-secondary); }
.article-hero__divider { border: none; border-top: 1px solid var(--border); margin: 2rem 0; }
.article-hero__info {
  display: flex;
  align-items: center;
  gap: 1.5rem;
  flex-wrap: wrap;
}
.article-hero__author { display: flex; align-items: center; gap: 0.75rem; }
.article-hero__avatar {
  width: 42px; height: 42px;
  border-radius: 50%;
  background: linear-gradient(135deg, var(--accent), var(--accent2));
  display: grid;
  place-items: center;
  font-size: 0.95rem;
  font-weight: 700;
  color: #fff;
}
.article-hero__author-name { font-weight: 600; font-size: 0.95rem; }
.article-hero__author-role { font-size: 0.78rem; color: var(--text-muted); }
.article-hero__stat { font-size: 0.82rem; color: var(--text-muted); display: flex; align-items: center; gap: 0.35rem; }

/*  Article Body */
.article-layout {
  display: grid;
  grid-template-columns: 1fr 280px;
  gap: 3rem;
  align-items: start;
  padding-bottom: 5rem;
}
.article-content {
  min-width: 0;
}
.article-content h2 { font-size: 1.6rem; margin: 2.5rem 0 1rem; padding-bottom: 0.5rem; border-bottom: 1px solid var(--border); }
.article-content h3 { font-size: 1.2rem; margin: 2rem 0 0.75rem; color: var(--accent); }
.article-content p  { color: var(--text-secondary); margin-bottom: 1.25rem; font-size: 1.02rem; line-height: 1.8; }
.article-content ul, .article-content ol { color: var(--text-secondary); padding-left: 1.5rem; margin-bottom: 1.25rem; }
.article-content li  { margin-bottom: 0.5rem; font-size: 1.02rem; line-height: 1.8; }
.article-content ul  { list-style: disc; }
.article-content ol  { list-style: decimal; }
.article-content blockquote {
  border-left: 3px solid var(--accent);
  padding: 1rem 1.5rem;
  background: var(--accent-glow);
  border-radius: 0 var(--radius-sm) var(--radius-sm) 0;
  margin: 1.75rem 0;
  color: var(--text-secondary);
  font-style: italic;
}
.article-content strong { color: var(--text-primary); font-weight: 700; }
.article-content a     { color: var(--accent); border-bottom: 1px dashed var(--accent-dim); }
.article-content a:hover { border-bottom-style: solid; }

/* Code blocks */
.article-content pre {
  background: var(--bg-secondary);
  border: 1px solid var(--border);
  border-radius: var(--radius-sm);
  padding: 1.25rem;
  overflow-x: auto;
  margin: 1.75rem 0;
  position: relative;
}
.article-content pre::before {
  content: attr(data-lang);
  position: absolute;
  top: 0.5rem; right: 0.75rem;
  font-family: var(--font-mono);
  font-size: 0.7rem;
  color: var(--text-muted);
  text-transform: uppercase;
  letter-spacing: 0.1em;
}
.article-content code {
  font-family: var(--font-mono);
  font-size: 0.88rem;
  color: var(--accent);
  background: rgba(0,201,201,0.08);
  padding: 0.1em 0.4em;
  border-radius: 3px;
}
.article-content pre code {
  background: none;
  color: #e8f0fe;
  padding: 0;
}

/* Math */
.math-block {
  background: var(--bg-secondary);
  border: 1px solid var(--border);
  border-radius: var(--radius-sm);
  padding: 1.25rem 1.5rem;
  margin: 1.75rem 0;
  text-align: center;
  overflow-x: auto;
  color: var(--text-primary);
  font-size: 1.1rem;
}
.math-caption {
  font-size: 0.8rem;
  color: var(--text-muted);
  text-align: center;
  margin-top: 0.4rem;
}

/* Callout */
.callout {
  display: flex;
  gap: 0.75rem;
  padding: 1rem 1.25rem;
  border-radius: var(--radius-sm);
  margin: 1.75rem 0;
  border: 1px solid;
}
.callout--info  { background: rgba(0,201,201,0.06);  border-color: rgba(0,201,201,0.2);  }
.callout--warn  { background: rgba(251,191,36,0.06); border-color: rgba(251,191,36,0.2); }
.callout--tip   { background: rgba(34,197,94,0.06);  border-color: rgba(34,197,94,0.2);  }
.callout__icon  { font-size: 1.1rem; flex-shrink: 0; margin-top: 0.1rem; }
.callout__body  { font-size: 0.92rem; color: var(--text-secondary); }
.callout__body p { margin: 0; }
.callout--info .callout__icon  { color: var(--accent); }
.callout--warn .callout__icon  { color: #fbbf24; }
.callout--tip  .callout__icon  { color: #22c55e; }

/* Sidebar TOC */
.article-sidebar {
  position: sticky;
  top: 5.5rem;
}
.toc {
  background: var(--bg-card);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 1.25rem;
}
.toc__title {
  font-size: 0.78rem;
  text-transform: uppercase;
  letter-spacing: 0.1em;
  color: var(--text-muted);
  font-weight: 700;
  margin-bottom: 1rem;
}
.toc__list { list-style: none; padding: 0; display: flex; flex-direction: column; gap: 0.25rem; }
.toc__list li a {
  display: block;
  padding: 0.3rem 0.6rem;
  font-size: 0.84rem;
  color: var(--text-secondary);
  border-left: 2px solid var(--border);
  border-radius: 0 var(--radius-sm) var(--radius-sm) 0;
  transition: all var(--transition);
  line-height: 1.4;
}
.toc__list li a:hover, .toc__list li a.active {
  color: var(--accent);
  border-left-color: var(--accent);
  background: var(--accent-glow);
  padding-left: 0.9rem;
}
.toc__list--sub a { font-size: 0.8rem; padding-left: 1.1rem; }

/* Author Bio Card */
.author-bio {
  background: var(--bg-card);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 2rem;
  margin: 3rem 0;
  display: flex;
  gap: 1.5rem;
  align-items: flex-start;
}
.author-bio__avatar {
  width: 70px; height: 70px;
  border-radius: 50%;
  background: linear-gradient(135deg, var(--accent), var(--accent2));
  display: grid;
  place-items: center;
  font-size: 1.5rem;
  font-weight: 700;
  color: #fff;
  flex-shrink: 0;
}
.author-bio__name { font-size: 1.1rem; font-weight: 700; margin-bottom: 0.3rem; }
.author-bio__role { font-size: 0.82rem; color: var(--accent); font-weight: 600; margin-bottom: 0.75rem; }
.author-bio__desc { font-size: 0.9rem; color: var(--text-secondary); margin-bottom: 1rem; }
.author-bio__links { display: flex; gap: 0.75rem; flex-wrap: wrap; }
.author-bio__link {
  font-size: 0.82rem;
  font-weight: 600;
  color: var(--text-secondary);
  border: 1px solid var(--border);
  padding: 0.3rem 0.8rem;
  border-radius: 99px;
  transition: all var(--transition);
}
.author-bio__link:hover { color: var(--accent); border-color: var(--accent-dim); background: var(--accent-glow); }

/* Related Posts */
.related-posts { padding: 3rem 0 5rem; border-top: 1px solid var(--border); }
.related-posts__title { margin-bottom: 1.5rem; }

/* ============================================================
   ABOUT PAGE
   ============================================================ */
.about-hero {
  padding: 7rem 0 4rem;
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 4rem;
  align-items: center;
}
.about-hero__badge { margin-bottom: 1.25rem; }
.about-hero__title { margin-bottom: 1rem; }
.about-hero__desc  { margin-bottom: 1.75rem; font-size: 1.05rem; }
.about__skills {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 1rem;
  margin-top: 2rem;
}
.skill-item {
  background: var(--bg-card);
  border: 1px solid var(--border);
  border-radius: var(--radius-sm);
  padding: 1rem;
  transition: all var(--transition);
}
.skill-item:hover { border-color: var(--accent-dim); background: var(--bg-card-hover); }
.skill-item__icon { font-size: 1.5rem; margin-bottom: 0.5rem; }
.skill-item__name { font-size: 0.9rem; font-weight: 600; color: var(--text-primary); }
.about-visual {
  position: relative;
  display: flex;
  align-items: center;
  justify-content: center;
}
.profile-card {
  background: var(--bg-card);
  border: 1px solid var(--border);
  border-radius: var(--radius-lg);
  padding: 2.5rem;
  text-align: center;
  width: 100%;
  max-width: 340px;
  box-shadow: var(--shadow-lg);
}
.profile-card__avatar {
  width: 90px; height: 90px;
  border-radius: 50%;
  background: linear-gradient(135deg, var(--accent), var(--accent2));
  display: grid;
  place-items: center;
  font-size: 2rem;
  font-weight: 700;
  color: #fff;
  margin: 0 auto 1rem;
  border: 3px solid var(--bg-primary);
  box-shadow: 0 0 0 3px var(--accent);
}
.profile-card__name { font-size: 1.2rem; font-weight: 700; margin-bottom: 0.25rem; }
.profile-card__title { font-size: 0.85rem; color: var(--accent); margin-bottom: 1.5rem; }
.profile-card__stats {
  display: grid;
  grid-template-columns: 1fr 1fr 1fr;
  gap: 0.5rem;
  margin-bottom: 1.5rem;
}
.profile-stat { background: var(--bg-secondary); border-radius: var(--radius-sm); padding: 0.75rem 0.5rem; }
.profile-stat__val { font-size: 1.25rem; font-weight: 800; color: var(--accent); display: block; }
.profile-stat__lbl { font-size: 0.7rem; color: var(--text-muted); }

/* ============================================================
   FOOTER
   ============================================================ */
.footer {
  background: var(--bg-secondary);
  border-top: 1px solid var(--border);
  padding: 4rem 0 2rem;
}
.footer__grid {
  display: grid;
  grid-template-columns: 2fr 1fr 1fr 1fr;
  gap: 2.5rem;
  margin-bottom: 3rem;
}
.footer__brand { max-width: 280px; }
.footer__brand-logo {
  display: flex;
  align-items: center;
  gap: 0.6rem;
  font-size: 1rem;
  font-weight: 800;
  color: var(--text-primary);
  margin-bottom: 1rem;
}
.footer__brand-logo-icon {
  width: 30px; height: 30px;
  background: linear-gradient(135deg, var(--accent), var(--accent2));
  border-radius: var(--radius-sm);
  display: grid;
  place-items: center;
  font-size: 0.9rem;
}
.footer__brand-desc { font-size: 0.88rem; color: var(--text-secondary); line-height: 1.7; margin-bottom: 1.25rem; }
.footer__social { display: flex; gap: 0.6rem; }
.social-link {
  width: 34px; height: 34px;
  border-radius: var(--radius-sm);
  background: var(--bg-card);
  border: 1px solid var(--border);
  display: grid;
  place-items: center;
  font-size: 0.9rem;
  transition: all var(--transition);
  color: var(--text-secondary);
}
.social-link:hover { background: var(--accent); color: #000; border-color: var(--accent); }
.footer__col-title { font-size: 0.78rem; font-weight: 700; text-transform: uppercase; letter-spacing: 0.1em; color: var(--text-muted); margin-bottom: 1.25rem; }
.footer__links { display: flex; flex-direction: column; gap: 0.6rem; }
.footer__links a { font-size: 0.88rem; color: var(--text-secondary); transition: color var(--transition); }
.footer__links a:hover { color: var(--accent); }
.footer__bottom {
  padding-top: 2rem;
  border-top: 1px solid var(--border);
  display: flex;
  align-items: center;
  justify-content: space-between;
  font-size: 0.82rem;
  color: var(--text-muted);
  flex-wrap: wrap;
  gap: 0.75rem;
}
.footer__bottom a { color: var(--text-muted); }
.footer__bottom a:hover { color: var(--accent); }

/* ============================================================
   PROGRESS BAR
   ============================================================ */
#reading-progress {
  position: fixed;
  top: 0; left: 0;
  height: 3px;
  background: linear-gradient(90deg, var(--accent), var(--accent2));
  width: 0%;
  z-index: 9999;
  transition: width 0.1s linear;
}

/* ============================================================
   BACK TO TOP
   ============================================================ */
#back-to-top {
  position: fixed;
  bottom: 2rem; right: 2rem;
  width: 42px; height: 42px;
  background: var(--bg-card);
  border: 1px solid var(--border);
  border-radius: var(--radius-sm);
  display: grid;
  place-items: center;
  cursor: pointer;
  font-size: 1rem;
  color: var(--text-secondary);
  opacity: 0;
  pointer-events: none;
  transition: all var(--transition);
  z-index: 100;
}
#back-to-top.visible { opacity: 1; pointer-events: auto; }
#back-to-top:hover { background: var(--accent); color: #000; border-color: var(--accent); }

/* ============================================================
   UTILITY CLASSES
   ============================================================ */
.text-center           { text-align: center; }
.mb-sm                 { margin-bottom: 0.75rem; }
.mb-md                 { margin-bottom: 2rem; }
.mt-lg                 { margin-top: 2.5rem; }
.pt-md                 { padding-top: 2rem; }
.center-actions        { text-align: center; margin-top: 2.5rem; }
.mission-grid          { display: grid; gap: 1.5rem; }
.contact-actions       { display: flex; gap: 1rem; justify-content: center; flex-wrap: wrap; }
.btn--full             { width: 100%; justify-content: center; }

/* ============================================================
   RESPONSIVE
   ============================================================ */
@media (max-width: 1024px) {
  .hero__content           { grid-template-columns: 1fr; gap: 2.5rem; }
  .hero__visual            { display: none; }
  .categories__grid        { grid-template-columns: 1fr 1fr; }
  .posts-grid--featured    { grid-template-columns: 1fr; }
  .posts-grid--featured .post-card:first-child { grid-column: auto; grid-template-columns: 1fr; }
  .posts-grid--featured .post-card:first-child .post-card__cover { height: 220px; }
  .article-layout          { grid-template-columns: 1fr; }
  .article-sidebar         { display: none; }
  .footer__grid            { grid-template-columns: 1fr 1fr; }
  .about-hero              { grid-template-columns: 1fr; }
  .about-visual            { display: none; }
}
@media (max-width: 768px) {
  .nav__links              { display: none; }
  .nav__cta .btn           { display: none; }
  .nav__hamburger          { display: flex; }
  .categories__grid        { grid-template-columns: 1fr; }
  .posts-grid              { grid-template-columns: 1fr; }
  .newsletter              { padding: 2rem 1.25rem; }
  .newsletter__form        { flex-direction: column; }
  .footer__grid            { grid-template-columns: 1fr; }
  .author-bio              { flex-direction: column; }
  .search-box              { margin-left: 0; width: 100%; }
  .search-box__input       { width: 100%; }
  .search-box__input:focus { width: 100%; }
  .hero__stats             { grid-template-columns: 1fr 1fr; }
}
@media (max-width: 480px) {
  .hero__actions           { flex-direction: column; }
  .hero__actions .btn      { width: 100%; justify-content: center; }
}