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

:root {
  --bg:        #0d1117;
  --bg-card:   #161b22;
  --bg-accent: #1f2937;
  --border:    #30363d;
  --primary:   #58a6ff;
  --primary-d: #1f6feb;
  --green:     #3fb950;
  --orange:    #f0883e;
  --red:       #f85149;
  --gold:      #e3a008;
  --text:      #c9d1d9;
  --text-dim:  #8b949e;
  --white:     #e6edf3;
  --font:      'Segoe UI', system-ui, -apple-system, sans-serif;
  --mono:      'Cascadia Code', 'Fira Code', 'Consolas', monospace;
  --radius:    8px;
  --shadow:    0 4px 24px rgba(0,0,0,.4);
}

html { scroll-behavior: smooth; }

body {
  background: var(--bg);
  color: var(--text);
  font-family: var(--font);
  font-size: 15px;
  line-height: 1.7;
  min-height: 100vh;
}

a { color: var(--primary); text-decoration: none; }
a:hover { text-decoration: underline; }

/* ── Nav ──────────────────────────────────────────────────────── */
nav {
  position: sticky;
  top: 0;
  z-index: 100;
  background: rgba(13,17,23,.92);
  backdrop-filter: blur(10px);
  border-bottom: 1px solid var(--border);
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 0 2rem;
  height: 58px;
}

.nav-brand {
  font-family: var(--mono);
  font-size: .95rem;
  font-weight: 700;
  color: var(--primary);
  white-space: nowrap;
  letter-spacing: .03em;
  display: flex;
  align-items: center;
  gap: .4rem;
}

.nav-brand .brand-icon { color: var(--green); font-size: 1.1rem; }
.nav-brand .brand-dot  { color: var(--orange); }

.nav-tabs {
  display: flex;
  gap: .25rem;
  list-style: none;
}

.nav-tabs li button {
  background: none;
  border: none;
  cursor: pointer;
  font-family: var(--font);
  font-size: .88rem;
  color: var(--text-dim);
  padding: .45rem .9rem;
  border-radius: var(--radius);
  transition: color .2s, background .2s;
}

.nav-tabs li button:hover {
  color: var(--white);
  background: var(--bg-accent);
}

.nav-tabs li button.active {
  color: var(--primary);
  background: rgba(88,166,255,.12);
}

.hamburger {
  display: none;
  background: none;
  border: none;
  cursor: pointer;
  color: var(--text);
  font-size: 1.4rem;
  padding: .3rem .5rem;
}

/* ── Tab panels ───────────────────────────────────────────────── */
.tab-panel { display: none; animation: fadeIn .35s ease; }
.tab-panel.active { display: block; }

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

/* ── Hero ─────────────────────────────────────────────────────── */
.hero {
  background: linear-gradient(135deg, #0d1117 0%, #101d2c 60%, #0d1117 100%);
  border-bottom: 1px solid var(--border);
  padding: 5rem 2rem 4rem;
  text-align: center;
  position: relative;
  overflow: hidden;
}

.hero::before {
  content: '';
  position: absolute;
  inset: 0;
  background: radial-gradient(ellipse 70% 50% at 50% 0%, rgba(88,166,255,.08) 0%, transparent 70%);
  pointer-events: none;
}

.hero-avatar {
  width: 110px;
  height: 110px;
  border-radius: 50%;
  background: linear-gradient(135deg, var(--primary-d), var(--green));
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 2.8rem;
  margin: 0 auto 1.5rem;
  box-shadow: 0 0 0 4px rgba(88,166,255,.25), var(--shadow);
}

.hero h1 {
  font-size: clamp(1.8rem, 4vw, 2.8rem);
  font-weight: 700;
  color: var(--white);
  letter-spacing: -.02em;
}

.hero-title {
  font-family: var(--mono);
  font-size: clamp(.85rem, 2vw, 1rem);
  color: var(--primary);
  margin: .5rem 0 .6rem;
  letter-spacing: .04em;
}

/* ── Role badges row (Author | Architect | Founder) ──────────── */
.role-badges {
  display: flex;
  gap: .6rem;
  justify-content: center;
  flex-wrap: wrap;
  margin: .6rem 0 1.2rem;
}

.role-badge {
  display: inline-flex;
  align-items: center;
  gap: .4rem;
  padding: .32rem 1rem;
  border-radius: 999px;
  font-size: .8rem;
  font-weight: 700;
  letter-spacing: .05em;
  text-transform: uppercase;
}

.role-badge.author   { background: rgba(63,185,80,.15);  border: 1px solid rgba(63,185,80,.5);  color: var(--green);  }
.role-badge.architect{ background: rgba(88,166,255,.15); border: 1px solid rgba(88,166,255,.5); color: var(--primary);}
.role-badge.founder  { background: rgba(227,160,8,.15);  border: 1px solid rgba(227,160,8,.5);  color: var(--gold);   }

.hero-sub {
  max-width: 620px;
  margin: 0 auto 2rem;
  color: var(--text-dim);
  font-size: .97rem;
}

.badge-row {
  display: flex;
  flex-wrap: wrap;
  gap: .6rem;
  justify-content: center;
  margin-bottom: 2rem;
}

.badge {
  display: inline-flex;
  align-items: center;
  gap: .35rem;
  background: var(--bg-card);
  border: 1px solid var(--border);
  border-radius: 999px;
  padding: .28rem .85rem;
  font-size: .78rem;
  color: var(--text-dim);
}

.badge .dot {
  width: 7px;
  height: 7px;
  border-radius: 50%;
  background: var(--green);
  animation: pulse 2s infinite;
}

@keyframes pulse { 0%,100% { opacity: 1; } 50% { opacity: .35; } }

.cta-row {
  display: flex;
  gap: .9rem;
  justify-content: center;
  flex-wrap: wrap;
}

.btn {
  display: inline-flex;
  align-items: center;
  gap: .45rem;
  padding: .6rem 1.4rem;
  border-radius: var(--radius);
  font-size: .88rem;
  font-weight: 600;
  cursor: pointer;
  border: none;
  transition: opacity .2s, transform .15s;
}

.btn:hover { opacity: .85; transform: translateY(-1px); text-decoration: none; }
.btn-primary { background: var(--primary-d); color: #fff; }
.btn-ghost { background: transparent; border: 1px solid var(--border); color: var(--text); }
.btn-substack { background: rgba(255,105,0,.15); border: 1px solid rgba(255,105,0,.5); color: #ff6900; }
.btn-substack:hover { background: rgba(255,105,0,.25); }

/* ── Section container ────────────────────────────────────────── */
.container {
  max-width: 960px;
  margin: 0 auto;
  padding: 3rem 2rem;
}

.section-title {
  font-size: 1.35rem;
  font-weight: 700;
  color: var(--white);
  margin-bottom: 1.5rem;
  display: flex;
  align-items: center;
  gap: .6rem;
}

.section-title::after {
  content: '';
  flex: 1;
  height: 1px;
  background: var(--border);
}

/* ── Cards ────────────────────────────────────────────────────── */
.card {
  background: var(--bg-card);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 1.4rem 1.6rem;
  margin-bottom: 1.2rem;
  transition: border-color .2s;
}

.card:hover { border-color: var(--primary-d); }

.card h3 {
  font-size: 1.02rem;
  font-weight: 600;
  color: var(--white);
  margin-bottom: .3rem;
}

.card p { font-size: .9rem; color: var(--text-dim); }

/* ── Grid helpers ─────────────────────────────────────────────── */
.grid-2 { display: grid; grid-template-columns: repeat(auto-fit, minmax(280px, 1fr)); gap: 1.2rem; }
.grid-3 { display: grid; grid-template-columns: repeat(auto-fit, minmax(200px, 1fr)); gap: 1rem; }

/* ── Stat cards ───────────────────────────────────────────────── */
.stat-card {
  background: var(--bg-card);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 1.4rem;
  text-align: center;
}

.stat-card .stat-num {
  font-size: 2.2rem;
  font-weight: 800;
  color: var(--primary);
  line-height: 1;
}

.stat-card .stat-label {
  font-size: .82rem;
  color: var(--text-dim);
  margin-top: .35rem;
}

/* ── Tech tags ────────────────────────────────────────────────── */
.tag-cloud {
  display: flex;
  flex-wrap: wrap;
  gap: .6rem;
  margin-top: .9rem;
}

.tag {
  background: var(--bg-accent);
  border: 1px solid var(--border);
  border-radius: 4px;
  padding: .22rem .65rem;
  font-family: var(--mono);
  font-size: .78rem;
  color: var(--text-dim);
  transition: border-color .2s, color .2s;
}

.tag:hover { border-color: var(--primary); color: var(--primary); }

.tag.green  { border-color: rgba(63,185,80,.4);  color: var(--green); }
.tag.orange { border-color: rgba(240,136,62,.4); color: var(--orange); }
.tag.blue   { border-color: rgba(88,166,255,.4); color: var(--primary); }
.tag.red    { border-color: rgba(248,81,73,.4);  color: var(--red); }

/* ── Timeline ─────────────────────────────────────────────────── */
.timeline { position: relative; padding-left: 1.8rem; }

.timeline::before {
  content: '';
  position: absolute;
  left: 6px;
  top: 6px;
  bottom: 6px;
  width: 2px;
  background: var(--border);
}

.tl-item {
  position: relative;
  margin-bottom: 2rem;
}

.tl-item::before {
  content: '';
  position: absolute;
  left: -1.55rem;
  top: 6px;
  width: 10px;
  height: 10px;
  border-radius: 50%;
  background: var(--primary);
  box-shadow: 0 0 0 3px rgba(88,166,255,.2);
}

.tl-date {
  font-family: var(--mono);
  font-size: .75rem;
  color: var(--text-dim);
  margin-bottom: .15rem;
}

.tl-title {
  font-weight: 600;
  color: var(--white);
  font-size: .97rem;
}

.tl-sub {
  color: var(--primary);
  font-size: .85rem;
  margin-bottom: .3rem;
}

.tl-desc { font-size: .88rem; color: var(--text-dim); }

/* ── Cert card ────────────────────────────────────────────────── */
.cert-card {
  background: var(--bg-card);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 1.1rem 1.4rem;
  display: flex;
  gap: 1rem;
  align-items: flex-start;
  transition: border-color .2s;
}

.cert-card:hover { border-color: var(--orange); }

.cert-icon {
  font-size: 1.6rem;
  flex-shrink: 0;
  margin-top: .1rem;
}

.cert-body h4 { color: var(--white); font-size: .92rem; font-weight: 600; }
.cert-body p  { color: var(--text-dim); font-size: .8rem; margin-top: .15rem; }

/* ── Progress bars ────────────────────────────────────────────── */
.skill-row { margin-bottom: 1rem; }

.skill-row .skill-header {
  display: flex;
  justify-content: space-between;
  margin-bottom: .35rem;
  font-size: .85rem;
}

.skill-row .skill-name { color: var(--white); font-weight: 500; }
.skill-row .skill-pct  { color: var(--text-dim); font-family: var(--mono); font-size: .78rem; }

.skill-bar {
  height: 6px;
  background: var(--bg-accent);
  border-radius: 999px;
  overflow: hidden;
}

.skill-fill {
  height: 100%;
  border-radius: 999px;
  background: linear-gradient(90deg, var(--primary-d), var(--primary));
  transition: width .8s ease;
}

/* ── Article cards ────────────────────────────────────────────── */
.article-card {
  background: var(--bg-card);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 1.4rem 1.6rem;
  display: flex;
  gap: 1.2rem;
  align-items: flex-start;
  transition: border-color .2s;
}

.article-card:hover { border-color: var(--primary-d); }

.article-card a {
  display: block;
  flex: 1;
  text-decoration: none;
}

.article-card a:hover .article-body h3 { color: var(--primary); }

.article-num {
  font-family: var(--mono);
  font-size: 1.6rem;
  font-weight: 700;
  color: var(--border);
  line-height: 1;
  flex-shrink: 0;
  min-width: 2rem;
}

.article-body { flex: 1; }
.article-body h3 { color: var(--white); font-size: .97rem; margin-bottom: .25rem; transition: color .2s; }
.article-body p  { color: var(--text-dim); font-size: .85rem; }

.article-meta {
  display: flex;
  gap: .8rem;
  margin-top: .5rem;
  font-size: .75rem;
  color: var(--text-dim);
  font-family: var(--mono);
}

/* ── Substack CTA ─────────────────────────────────────────────── */
.substack-cta {
  background: linear-gradient(135deg, rgba(255,105,0,.08), rgba(255,105,0,.03));
  border: 1px solid rgba(255,105,0,.3);
  border-radius: var(--radius);
  padding: 2rem;
  text-align: center;
  margin-top: 2rem;
}

.substack-cta h3 { color: var(--white); font-size: 1.1rem; margin-bottom: .5rem; }
.substack-cta p  { color: var(--text-dim); font-size: .9rem; margin-bottom: 1.2rem; }

/* ── Contact ──────────────────────────────────────────────────── */
.contact-grid { display: grid; grid-template-columns: repeat(auto-fit, minmax(220px, 1fr)); gap: 1rem; }

.contact-item {
  background: var(--bg-card);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 1.3rem 1.5rem;
  display: flex;
  align-items: center;
  gap: 1rem;
  transition: border-color .2s;
  text-decoration: none;
}

.contact-item:hover { border-color: var(--primary); text-decoration: none; }

.contact-icon {
  font-size: 1.4rem;
  flex-shrink: 0;
}

.contact-body small { display: block; color: var(--text-dim); font-size: .75rem; }
.contact-body span  { color: var(--white); font-size: .88rem; font-weight: 500; }

/* ── Footer ───────────────────────────────────────────────────── */
footer {
  border-top: 1px solid var(--border);
  text-align: center;
  padding: 2rem;
  color: var(--text-dim);
  font-size: .82rem;
  font-family: var(--mono);
}

footer span { color: var(--primary); }

/* ── Responsive ───────────────────────────────────────────────── */
@media (max-width: 640px) {
  nav { padding: 0 1rem; }
  .nav-tabs { display: none; flex-direction: column; position: absolute; top: 58px; left: 0; right: 0; background: var(--bg-card); border-bottom: 1px solid var(--border); padding: .5rem; }
  .nav-tabs.open { display: flex; }
  .hamburger { display: block; }
  .hero { padding: 3rem 1.2rem 2.5rem; }
  .container { padding: 2rem 1.2rem; }
}