/* =====================================================
   YOLANDA SABUCO — Portfolio Website
   Design: Academic, Clean, Professional
   ===================================================== */

@import url('https://fonts.googleapis.com/css2?family=Figtree:wght@300;400;500;600;700;800&family=Noto+Sans:ital,wght@0,300;0,400;0,500;0,700;1,400&family=JetBrains+Mono:wght@400;500&display=swap');

/* === VARIABLES === */
:root {
  --bg: #1a1a1a;
  --surface: #242424;
  --surface-2: #2e2e2e;
  --border: rgba(255,255,255,0.10);
  --text: #f2f2f2;
  --text-secondary: #a8a8a8;
  --text-muted: #6e6e6e;
  --accent: #c8963c;
  --accent-hover: #b5832f;
  --accent-warm: #c8963c;
  --accent-warm-hover: #b5832f;
  --accent-warm-light: rgba(200,150,60,0.10);
  --accent-light: rgba(200,150,60,0.10);
  --tag-bg: rgba(255,255,255,0.06);
  --tag-text: #8a8a8a;

  --font-serif: 'Figtree', sans-serif;
  --font-sans: 'Noto Sans', system-ui, -apple-system, sans-serif;
  --font-mono: 'JetBrains Mono', 'Courier New', monospace;

  --banner-height: 36px;
  --nav-height: 64px;
  --max-width: 1100px;
  --max-narrow: 760px;
  --radius-sm: 4px;
  --radius-md: 8px;
  --radius-lg: 14px;

  --shadow-sm: 0 1px 3px rgba(0,0,0,0.45);
  --shadow-md: 0 4px 16px rgba(0,0,0,0.55);
  --shadow-lg: 0 8px 32px rgba(0,0,0,0.65);

  --transition: 200ms ease;
  --transition-slow: 400ms ease;

  /* aliases for ported components */
  --a1: var(--accent);
  --a2: #34d399;
  --a3: var(--accent-warm);
  --muted: var(--text-secondary);
  --fh: var(--font-serif);
  --r: var(--radius-lg);
  --ease: cubic-bezier(.4,0,.2,1);
}

/* === SCROLLBAR === */
::-webkit-scrollbar { width: 3px; }
::-webkit-scrollbar-track { background: var(--bg); }
::-webkit-scrollbar-thumb { background: var(--accent); border-radius: 2px; }

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

html {
  scroll-behavior: smooth;
  scroll-padding-top: var(--nav-height);
  font-size: 16px;
}

body {
  font-family: var(--font-sans);
  line-height: 1.65;
  color: var(--text);
  background: var(--bg);
  -webkit-font-smoothing: antialiased;
  overflow-x: hidden;
}

img { max-width: 100%; height: auto; display: block; }
a { color: var(--accent); text-decoration: none; transition: color var(--transition); }
a:hover { color: var(--accent-warm); }
ul, ol { list-style: none; }

/* === TYPOGRAPHY === */
h1, h2, h3, h4, h5 {
  font-family: var(--font-serif);
  font-weight: 600;
  line-height: 1.2;
  color: var(--text);
}
h1 { font-size: clamp(2.4rem, 5vw, 3.6rem); }
h2 { font-size: clamp(1.7rem, 3.5vw, 2.4rem); }
h3 { font-size: clamp(1.2rem, 2.5vw, 1.6rem); }
h4 { font-size: 1.1rem; }
p { margin-bottom: 1em; }
p:last-child { margin-bottom: 0; }

code {
  font-family: var(--font-mono);
  font-size: 0.87em;
  background: var(--surface-2);
  padding: 0.15em 0.4em;
  border-radius: var(--radius-sm);
  color: #34d399;
}

pre {
  font-family: var(--font-mono);
  background: #0d1117;
  color: #e6edf3;
  padding: 1.5rem;
  border-radius: var(--radius-md);
  overflow-x: auto;
  font-size: 0.875rem;
  line-height: 1.65;
  margin: 1.5rem 0;
  border: 1px solid #30363d;
}
pre code { background: none; color: inherit; padding: 0; font-size: inherit; }

/* === LAYOUT === */
.container { max-width: var(--max-width); margin: 0 auto; padding: 0 1.5rem; }
.container--narrow { max-width: var(--max-narrow); }

section { padding: 5.5rem 0; }

.section-label {
  display: inline-block;
  font-size: 0.72rem;
  font-weight: 700;
  letter-spacing: 0.15em;
  text-transform: uppercase;
  color: var(--accent-warm);
  margin-bottom: 0.6rem;
}

.section-title { margin-bottom: 2.5rem; }
.section-title h2 { margin-bottom: 0.5rem; }
.section-title p { color: var(--text-secondary); max-width: 580px; }

.divider {
  width: 44px; height: 3px;
  background: linear-gradient(90deg, var(--accent-warm), var(--accent));
  border-radius: 2px;
  margin: 0.6rem 0 1.5rem;
}

/* === BUTTONS === */
.btn {
  display: inline-flex; align-items: center; gap: 0.5rem;
  padding: 0.6rem 1.35rem;
  border-radius: var(--radius-md);
  font-size: 0.88rem; font-weight: 500; font-family: var(--font-sans);
  cursor: pointer; border: 2px solid transparent;
  transition: all var(--transition);
  text-decoration: none; white-space: nowrap;
}
.btn--primary { background: var(--accent); color: #fff; }
.btn--primary:hover { background: var(--accent-hover); color: #fff; transform: translateY(-1px); box-shadow: var(--shadow-md); }
.btn--warm { background: var(--accent-warm); color: #fff; }
.btn--warm:hover { background: var(--accent-warm-hover); color: #fff; transform: translateY(-1px); box-shadow: var(--shadow-md); }
.btn--outline { background: transparent; color: var(--accent); border-color: var(--border); }
.btn--outline:hover { border-color: var(--accent); background: var(--accent-light); color: var(--accent); }

/* === AI BANNER === */
.ai-banner {
  position: fixed; top: 0; left: 0; right: 0; z-index: 200;
  height: var(--banner-height);
  display: flex; align-items: center; justify-content: center; gap: .6rem;
  font-size: .72rem; font-family: var(--font-sans); letter-spacing: .06em;
  text-transform: uppercase; color: rgba(255,255,255,0.88);
  background: linear-gradient(90deg, #7c3aed, #a855f7, #ec4899, #f59e0b, #a855f7, #7c3aed);
  background-size: 300% 100%;
  animation: bannerShift 6s linear infinite;
  overflow: hidden;
}
.ai-banner::after {
  content: '';
  position: absolute; inset: 0;
  background: linear-gradient(90deg, transparent 0%, rgba(255,255,255,0.12) 50%, transparent 100%);
  animation: bannerShimmer 2.4s ease-in-out infinite;
}
.ai-banner__sparkle {
  font-size: .8rem; opacity: .85;
  animation: sparkle 2s ease-in-out infinite alternate;
}
.ai-banner__text strong { font-weight: 700; letter-spacing: .03em; }

@keyframes bannerShift {
  0%   { background-position: 0% 50%; }
  100% { background-position: 300% 50%; }
}
@keyframes bannerShimmer {
  0%   { transform: translateX(-100%); }
  100% { transform: translateX(100%); }
}
@keyframes sparkle {
  from { transform: scale(1)   rotate(0deg);   opacity: .7; }
  to   { transform: scale(1.3) rotate(20deg);  opacity: 1; }
}

/* Offset nav + hero when banner is present */
.has-banner .nav           { top: var(--banner-height); }
.has-banner .nav__mobile-menu { top: calc(var(--banner-height) + var(--nav-height)); }
.has-banner .hero          { padding-top: calc(var(--banner-height) + var(--nav-height) + 4.5rem); }
html:has(body.has-banner)  { scroll-padding-top: calc(var(--banner-height) + var(--nav-height)); }

/* === NAVIGATION === */
.nav {
  position: fixed; top: 0; left: 0; right: 0; z-index: 100;
  height: var(--nav-height);
  background: rgba(12,12,12,0.94);
  backdrop-filter: blur(12px);
  border-bottom: 1px solid transparent;
  transition: border-color var(--transition), box-shadow var(--transition);
}
.nav.scrolled { border-color: var(--border); box-shadow: var(--shadow-sm); }

.nav__inner {
  display: flex; align-items: center; justify-content: space-between;
  height: 100%; max-width: var(--max-width); margin: 0 auto; padding: 0 1.5rem;
}

.nav__logo {
  display: flex; align-items: center; gap: 0.7rem;
  font-family: var(--font-serif); font-size: 1.1rem; font-weight: 600;
  color: var(--text);
}
.nav__logo img { height: 34px; width: auto; mix-blend-mode: screen; }

.nav__links { display: flex; align-items: center; gap: 0.15rem; }

.nav__link {
  font-size: 0.82rem; font-weight: 500; color: var(--text-secondary);
  padding: 0.35rem 0.65rem; border-radius: var(--radius-sm);
  transition: color var(--transition), background var(--transition);
}
.nav__link:hover, .nav__link.active { color: var(--accent); background: var(--accent-light); }

.nav__social { display: flex; align-items: center; gap: 0.3rem; margin-left: 0.5rem; }
.nav__social a {
  display: flex; align-items: center; justify-content: center;
  width: 30px; height: 30px; border-radius: 50%;
  background: var(--accent); color: var(--bg);
  transition: background var(--transition), transform var(--transition);
}
.nav__social a:hover { background: var(--accent-hover); transform: scale(1.08); color: var(--bg); }

.nav__hamburger {
  display: none; flex-direction: column; gap: 5px;
  cursor: pointer; padding: 0.4rem; background: none; border: none;
}
.nav__hamburger span { display: block; width: 22px; height: 2px; background: var(--text); transition: all var(--transition); }

.nav__mobile-menu {
  display: none;
  position: fixed; top: var(--nav-height); left: 0; right: 0;
  background: var(--bg); border-bottom: 1px solid var(--border);
  padding: 1rem 1.5rem; flex-direction: column; gap: 0.25rem;
  box-shadow: var(--shadow-md); z-index: 99;
}
.nav__mobile-menu.open { display: flex; }
.nav__mobile-link {
  padding: 0.6rem 0.75rem; color: var(--text); border-radius: var(--radius-sm);
  font-size: 0.95rem; font-weight: 500; transition: background var(--transition);
}
.nav__mobile-link:hover { background: var(--surface); color: var(--accent); }

/* === HERO === */
.hero {
  padding-top: calc(var(--nav-height) + 4.5rem);
  padding-bottom: 5rem;
  min-height: 92vh;
  display: flex; align-items: center;
}

.hero__inner {
  display: grid;
  grid-template-columns: 1fr 340px;
  gap: 4rem; align-items: center;
}

.hero__open-to-work {
  display: inline-flex; align-items: center; gap: 0.5rem;
  background: rgba(34,197,94,0.1); border: 1px solid rgba(34,197,94,0.4);
  color: #22c55e; padding: 0.3rem 0.85rem; border-radius: 100px;
  font-size: 0.78rem; font-weight: 600; margin-bottom: 0.6rem;
  letter-spacing: 0.03em;
}
.hero__open-to-work::before {
  content: ''; width: 6px; height: 6px;
  background: #22c55e; border-radius: 50%;
  animation: pulse-green 2s ease-in-out infinite;
}
@keyframes pulse-green {
  0%, 100% { opacity: 1; transform: scale(1); }
  50% { opacity: 0.5; transform: scale(0.8); }
}

.hero__badge {
  display: inline-flex; align-items: center; gap: 0.5rem;
  background: var(--accent-warm-light); border: 1px solid rgba(245,158,11,0.35);
  color: var(--accent-warm); padding: 0.3rem 0.85rem; border-radius: 100px;
  font-size: 0.78rem; font-weight: 600; margin-bottom: 1.25rem;
  letter-spacing: 0.03em;
}
.hero__badge::before {
  content: ''; width: 6px; height: 6px;
  background: var(--accent-warm); border-radius: 50%;
}

.hero__name { font-size: clamp(2.8rem, 6vw, 4rem); line-height: 1.05; margin-bottom: 0.4rem; }
.hero__name .accent { color: var(--accent); }

.hero__title {
  font-family: var(--font-serif); font-size: clamp(1.05rem, 2vw, 1.3rem);
  color: var(--text-secondary); font-weight: 400; font-style: italic;
  margin-bottom: 1.5rem;
}

.hero__bio {
  font-size: 1rem; color: var(--text-secondary);
  line-height: 1.75; max-width: 500px; margin-bottom: 1.75rem;
}

.hero__stats { display: flex; gap: 2.5rem; margin-bottom: 2rem; }
.hero__stat-value { font-family: var(--font-serif); font-size: 2.2rem; font-weight: 700; color: var(--accent); line-height: 1; }
.hero__stat-label { font-size: 0.72rem; color: var(--text-muted); margin-top: 0.2rem; }

.hero__cta { display: flex; flex-wrap: wrap; gap: 0.75rem; }

.hero__img-wrapper { position: relative; }
.hero__img {
  width: 100%; aspect-ratio: 4/5; object-fit: cover;
  border-radius: var(--radius-lg);
  object-position: center top;
  filter: brightness(0.88) contrast(1.08) saturate(0.92);
  mask-image: radial-gradient(ellipse 78% 88% at 50% 38%, black 48%, transparent 86%);
  -webkit-mask-image: radial-gradient(ellipse 78% 88% at 50% 38%, black 48%, transparent 86%);
}
.hero__img-card {
  position: absolute; bottom: 1.5rem; left: -1.5rem;
  background: var(--bg); border-radius: var(--radius-md);
  padding: 0.8rem 1.1rem; box-shadow: var(--shadow-md);
  border: 1px solid var(--border);
}
.hero__img-card-val { font-family: var(--font-serif); font-size: 1.4rem; font-weight: 700; color: var(--accent-warm); line-height: 1; }
.hero__img-card-lbl { font-size: 0.68rem; color: var(--text-muted); margin-top: 0.2rem; }

/* === EXPERTISE === */
.expertise-section {
  background: var(--surface);
  position: relative;
  overflow: hidden;
}
.expertise-section::before {
  content: '';
  position: absolute;
  right: -6%;
  top: 50%;
  transform: translateY(-50%);
  width: 520px;
  height: 520px;
  background: url('../images/logo.png') center / contain no-repeat;
  opacity: 0.07;
  pointer-events: none;
  mix-blend-mode: screen;
}
.expertise-section .container {
  max-width: 1340px;
}

.expertise-grid {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 1.25rem;
}

.expertise-card {
  background: var(--surface-2);
  border: 1px solid var(--border);
  border-radius: var(--radius-lg);
  padding: 2rem;
  position: relative;
  overflow: hidden;
  transition: transform 300ms ease, border-color 300ms ease, box-shadow 300ms ease;
}
.expertise-card::after {
  content: '';
  position: absolute;
  top: 0; left: 0; right: 0;
  height: 2px;
  background: linear-gradient(90deg, var(--accent), #34d399);
  transform: scaleX(0);
  transform-origin: left;
  transition: transform 400ms ease;
}
.expertise-card:hover {
  transform: translateY(-5px);
  border-color: rgba(200,150,60,0.30);
  box-shadow: var(--shadow-lg);
}
.expertise-card:hover::after { transform: scaleX(1); }

.expertise-card__icon {
  width: 46px; height: 46px;
  border-radius: var(--radius-md);
  display: flex; align-items: center; justify-content: center;
  margin-bottom: 1.25rem;
}
.expertise-card__icon svg { width: 22px; height: 22px; }
.expertise-card__icon--blue  { background: rgba(200,150,60,0.12); color: var(--accent); }
.expertise-card__icon--green { background: rgba(52,211,153,0.12);  color: #34d399; }
.expertise-card__icon--amber { background: rgba(245,158,11,0.12);  color: var(--accent-warm); }
.expertise-card__icon--rose  { background: rgba(251,113,133,0.12); color: #fb7185; }

.expertise-card__title {
  font-family: var(--font-serif);
  font-weight: 700;
  font-size: 1rem;
  margin-bottom: 0.65rem;
  color: var(--text);
}
.expertise-card__text { color: var(--text-secondary); font-size: 0.875rem; line-height: 1.72; }

/* === EXPERIENCE TIMELINE === */
.exp-timeline { position: relative; max-width: 780px; }
.exp-timeline::before {
  content: ''; position: absolute;
  left: 0; top: 8px; bottom: 40px; width: 1px;
  background: linear-gradient(to bottom, var(--accent), transparent);
}

.t-item {
  padding-left: 2.75rem;
  padding-bottom: 3rem;
  position: relative;
}
.t-item:last-child { padding-bottom: 0; }
.t-item::before {
  content: ''; position: absolute;
  left: -5px; top: 6px;
  width: 11px; height: 11px; border-radius: 50%;
  background: var(--accent);
  box-shadow: 0 0 0 3px var(--bg), 0 0 0 6px rgba(200,150,60,0.25);
}

.t-date {
  font-size: 0.78rem; color: #34d399; font-weight: 600;
  letter-spacing: 0.04em; margin-bottom: 0.3rem;
}
.t-company {
  font-size: 1.1rem; font-weight: 800; margin-bottom: 0.2rem;
}
.t-role {
  font-size: 0.82rem; color: var(--accent); font-weight: 600;
  margin-bottom: 0.65rem;
}
.t-desc { color: var(--text-secondary); font-size: 0.875rem; line-height: 1.72; }

/* === SKILLS — Technical Arsenal === */
.sec-label {
  font-size: .72rem; font-weight: 700; letter-spacing: .12em;
  text-transform: uppercase; color: var(--accent);
  font-family: var(--font-serif); margin-bottom: .65rem;
}
.sec-sub {
  color: var(--text-secondary); max-width: 560px;
  line-height: 1.8; margin-bottom: 3.5rem;
}
/* === SKILLS GRID === */
.skills-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 1.25rem;
}
@media (max-width: 900px) { .skills-grid { grid-template-columns: repeat(2, 1fr); } }
@media (max-width: 560px)  { .skills-grid { grid-template-columns: 1fr; } }

.skill-card {
  background: var(--bg);
  border: 1px solid rgba(200,150,60,0.18);
  border-radius: 12px;
  padding: 1.4rem 1.4rem 1.2rem;
  display: flex; flex-direction: column; gap: .75rem;
  transition: border-color 300ms ease, box-shadow 300ms ease, transform 300ms ease;
  position: relative; overflow: hidden;
}
.skill-card::before {
  content: '';
  position: absolute; inset: 0;
  background: radial-gradient(ellipse at top left, rgba(200,150,60,0.07) 0%, transparent 65%);
  pointer-events: none;
}
.skill-card:hover {
  border-color: rgba(200,150,60,0.55);
  box-shadow: 0 0 22px rgba(200,150,60,0.15), 0 4px 24px rgba(0,0,0,0.35);
  transform: translateY(-3px);
}

.skill-card__icon {
  font-size: 1.5rem; line-height: 1;
}
.skill-card__title {
  font-size: .95rem; font-weight: 700;
  color: var(--accent); letter-spacing: .01em;
  font-family: var(--font-sans); margin: 0;
}
.skill-card__tags {
  display: flex; flex-wrap: wrap; gap: .4rem;
}
.stag {
  font-size: .75rem; font-family: var(--font-sans);
  background: rgba(200,150,60,0.10);
  color: var(--text-secondary);
  border: 1px solid rgba(200,150,60,0.22);
  border-radius: 999px;
  padding: .2rem .65rem;
  white-space: nowrap;
  transition: background 200ms ease, color 200ms ease, border-color 200ms ease;
}
.skill-card:hover .stag {
  background: rgba(200,150,60,0.18);
  color: var(--text);
  border-color: rgba(200,150,60,0.45);
}

/* === REVEAL ANIMATION (.r / .show) === */
.r { opacity: 0; transform: translateY(22px); transition: opacity 600ms var(--ease), transform 600ms var(--ease); }
.r.show { opacity: 1; transform: translateY(0); }
.r.d1 { transition-delay: 80ms; }
.r.d2 { transition-delay: 160ms; }
.r.d3 { transition-delay: 240ms; }
.r.d4 { transition-delay: 320ms; }

/* === PROJECTS === */
.projects__grid { display: grid; grid-template-columns: repeat(auto-fill, minmax(310px, 1fr)); gap: 1.4rem; }

.project-card {
  background: var(--bg); border: 1px solid var(--border); border-radius: var(--radius-lg);
  padding: 1.75rem; transition: transform 300ms var(--ease), border-color 300ms var(--ease), box-shadow 300ms var(--ease);
  position: relative; overflow: hidden; display: flex; flex-direction: column;
  text-decoration: none; color: inherit;
}
.project-card::before {
  content: ''; position: absolute; top: 0; left: 0; right: 0; height: 2px;
  background: linear-gradient(90deg, var(--accent), var(--accent-warm));
  transform: scaleX(0.12); transform-origin: left;
  transition: transform 300ms var(--ease), opacity 300ms;
  opacity: 0.45;
}
.project-card:hover { box-shadow: 0 16px 48px rgba(0,0,0,0.5); transform: translateY(-3px); border-color: rgba(200,150,60,0.22); }
.project-card:hover::before { transform: scaleX(1); opacity: 1; }
.project-card__num {
  position: absolute; top: 1.1rem; right: 1.25rem;
  font-family: var(--font-serif); font-size: 3.5rem; font-weight: 800; line-height: 1;
  color: rgba(200,150,60,0.07); letter-spacing: -0.03em; pointer-events: none; user-select: none;
  transition: color 300ms;
}
.project-card:hover .project-card__num { color: rgba(200,150,60,0.12); }
.project-card__title { font-family: var(--font-serif); font-size: 1.05rem; font-weight: 600; margin-bottom: 0.6rem; line-height: 1.4; padding-right: 2rem; }
.project-card__desc { font-size: 0.84rem; color: var(--text-secondary); margin-bottom: 1rem; line-height: 1.65; flex: 1; }
.project-card__tags { display: flex; flex-wrap: wrap; gap: 0.35rem; margin-bottom: 1.1rem; }
.project-card__link {
  font-size: 0.78rem; color: var(--accent); font-weight: 600;
  display: inline-flex; align-items: center; gap: 0.3rem;
  letter-spacing: 0.02em; transition: gap var(--transition), color var(--transition);
  margin-top: auto;
}
.project-card__link:hover { gap: 0.5rem; color: var(--accent-hover); }

.tag {
  background: var(--tag-bg); color: var(--tag-text);
  padding: 0.18rem 0.55rem; border-radius: 100px;
  font-size: 0.7rem; font-weight: 500;
}

/* === EDUCATION === */
.education__grid { display: grid; grid-template-columns: repeat(auto-fill, minmax(280px, 1fr)); gap: 1.25rem; }
.education-card {
  background: var(--bg);
  border: 1px solid rgba(200,150,60,0.18);
  border-radius: 12px;
  padding: 1.4rem;
  position: relative; overflow: hidden;
  transition: border-color 300ms ease, box-shadow 300ms ease, transform 300ms ease;
}
.education-card::before {
  content: '';
  position: absolute; top: 0; left: 0; right: 0; height: 2px;
  background: linear-gradient(90deg, transparent, var(--accent), transparent);
  opacity: 0;
  transition: opacity 300ms ease;
}
.education-card::after {
  content: '';
  position: absolute; inset: 0;
  background: radial-gradient(ellipse at top left, rgba(200,150,60,0.07) 0%, transparent 65%);
  pointer-events: none;
}
.education-card:hover {
  border-color: rgba(200,150,60,0.55);
  box-shadow: 0 0 22px rgba(200,150,60,0.15), 0 4px 24px rgba(0,0,0,0.35);
  transform: translateY(-3px);
}
.education-card:hover::before { opacity: 1; }
.education-card__degree { font-weight: 700; font-size: 1rem; margin-bottom: 0.35rem; color: var(--text); }
.education-card__school { font-size: 0.83rem; color: var(--text-secondary); margin-bottom: 0.75rem; }
.education-card__note { font-size: 0.75rem; color: var(--text-muted); font-style: italic; margin-bottom: 0.6rem; }
.education-badge {
  display: inline-block; background: rgba(200,150,60,0.10); color: var(--accent-warm);
  border: 1px solid rgba(200,150,60,0.28);
  padding: 0.18rem 0.65rem; border-radius: 999px; font-size: 0.7rem; font-weight: 600;
  font-family: var(--font-sans); letter-spacing: 0.03em;
}

.certs-grid { display: flex; flex-wrap: wrap; gap: 0.75rem; margin-top: 2rem; }
.cert-badge {
  display: flex; align-items: center; gap: 0.6rem;
  background: var(--bg); border: 1px solid var(--border); border-radius: var(--radius-md);
  padding: 0.6rem 0.95rem; font-size: 0.82rem; transition: all var(--transition);
}
.cert-badge:hover { border-color: var(--accent-warm); background: var(--accent-warm-light); }
.cert-badge__icon { font-size: 1.1rem; }
.cert-badge__issuer { font-size: 0.7rem; color: var(--text-muted); }

/* === PUBLICATIONS === */
.publications { background: var(--surface); }
.publications__list { display: flex; flex-direction: column; gap: 1rem; }
.pub-item {
  display: flex; gap: 1.1rem; align-items: flex-start;
  padding: 1.15rem 1.25rem; background: var(--bg);
  border-radius: var(--radius-md); border: 1px solid var(--border);
  transition: all var(--transition);
  text-decoration: none; color: inherit;
}
.pub-item:hover { border-color: var(--accent); background: var(--accent-light); }
.pub-item__year { flex-shrink: 0; font-family: var(--font-serif); font-size: 0.82rem; color: var(--accent-warm); font-weight: 600; min-width: 40px; padding-top: 0.15rem; }
.pub-item__type {
  display: inline-block; background: var(--tag-bg); color: var(--tag-text);
  padding: 0.12rem 0.5rem; border-radius: 100px; font-size: 0.68rem; font-weight: 600;
  margin-bottom: 0.3rem;
}
.pub-item__title { font-weight: 600; font-size: 0.92rem; margin-bottom: 0.2rem; color: var(--text); }
.pub-item__venue { font-size: 0.8rem; color: var(--text-muted); font-style: italic; }

/* === BLOG === */
.filter-row { display: flex; gap: .5rem; flex-wrap: wrap; margin-bottom: 2.5rem; }
.filter-btn {
  padding: .35rem .95rem; border-radius: 100px; border: 1px solid var(--border);
  background: transparent; color: var(--text-secondary);
  font-family: var(--font-serif); font-size: .78rem; font-weight: 600;
  cursor: pointer; transition: background 200ms, border-color 200ms, color 200ms;
}
.filter-btn:hover, .filter-btn.active {
  background: rgba(200,150,60,.12); border-color: rgba(200,150,60,.35); color: var(--accent);
}
.blog-grid { display: grid; grid-template-columns: repeat(auto-fill, minmax(300px, 1fr)); gap: 1.5rem; }
.blog-card {
  background: var(--surface-2); border: 1px solid var(--border);
  border-radius: var(--radius-lg); overflow: hidden; cursor: pointer;
  transition: transform 300ms var(--ease), border-color 300ms var(--ease), box-shadow 300ms var(--ease);
  text-decoration: none; color: inherit; display: flex; flex-direction: column;
}
.blog-card:hover { transform: translateY(-5px); border-color: rgba(200,150,60,.25); box-shadow: 0 20px 56px rgba(0,0,0,.45); }
.blog-card[hidden] { display: none; }
.blog-img { width: 100%; aspect-ratio: 16/9; object-fit: cover; transition: transform 400ms var(--ease); }
.blog-card:hover .blog-img { transform: scale(1.04); }
.blog-img-wrap { overflow: hidden; flex-shrink: 0; }
.blog-body { padding: 1.5rem; display: flex; flex-direction: column; flex: 1; }
.blog-meta { display: flex; align-items: center; gap: .6rem; margin-bottom: .85rem; }
.cat-pill { padding: .18rem .65rem; border-radius: 100px; font-size: .7rem; font-weight: 700; font-family: var(--font-serif); }
.cat-interoperability { background: rgba(200,150,60,.12); border: 1px solid rgba(200,150,60,.25); color: var(--accent); }
.cat-conferences      { background: rgba(245,158,11,.1);  border: 1px solid rgba(245,158,11,.25);  color: var(--accent-warm); }
.cat-security         { background: rgba(251,113,133,.1); border: 1px solid rgba(251,113,133,.25); color: #fb7185; }
.cat-personal         { background: rgba(52,211,153,.1);  border: 1px solid rgba(52,211,153,.25);  color: #34d399; }
.blog-date { font-size: .75rem; color: var(--text-secondary); font-family: var(--font-serif); }
.blog-title { font-family: var(--font-serif); font-weight: 700; font-size: .98rem; line-height: 1.45; margin-bottom: auto; }
.blog-read {
  display: inline-flex; align-items: center; gap: .35rem; margin-top: 1.25rem;
  font-family: var(--font-serif); font-size: .78rem; font-weight: 700;
  color: var(--accent); text-decoration: none; transition: gap 200ms;
}
.blog-card:hover .blog-read { gap: .55rem; }
.blog-read svg { width: 13px; height: 13px; }

/* === FSH TUTORIAL CALLOUT === */
.tut-callout {
  position: relative;
  overflow: hidden;
  padding: 6rem 0;
  background: linear-gradient(135deg, #8a6020 0%, #c8963c 45%, #b5832f 100%);
}
.tut-callout__sphere {
  position: absolute;
  right: -5%;
  top: 50%;
  transform: translateY(-50%);
  width: 600px;
  height: 600px;
  background: url('../images/logo.png') center / contain no-repeat;
  opacity: 0.18;
  mix-blend-mode: screen;
  pointer-events: none;
}
.tut-callout__inner {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 4rem;
  flex-wrap: wrap;
  position: relative;
  z-index: 1;
}
.tut-callout__content { flex: 1; min-width: 280px; }
.tut-callout__label {
  display: inline-block;
  font-size: 0.7rem;
  font-weight: 700;
  letter-spacing: 0.18em;
  text-transform: uppercase;
  color: rgba(255,255,255,0.6);
  margin-bottom: 1rem;
}
.tut-callout__title {
  font-family: var(--font-serif);
  font-size: clamp(2.4rem, 5vw, 3.8rem);
  font-weight: 800;
  color: #ffffff;
  line-height: 1.05;
  margin-bottom: 1.25rem;
  letter-spacing: -0.02em;
}
.tut-callout__desc {
  font-size: 1rem;
  color: rgba(255,255,255,0.78);
  line-height: 1.75;
  max-width: 500px;
  margin-bottom: 2rem;
}
.tut-callout__cta {
  display: inline-flex;
  align-items: center;
  gap: 0.55rem;
  background: #1a1a1a;
  color: #ffffff;
  padding: 0.75rem 1.6rem;
  border-radius: var(--radius-md);
  font-family: var(--font-serif);
  font-weight: 600;
  font-size: 0.95rem;
  text-decoration: none;
  transition: background 200ms, transform 200ms, box-shadow 200ms;
  box-shadow: 0 4px 18px rgba(0,0,0,0.35);
}
.tut-callout__cta:hover {
  background: #000;
  color: #ffffff;
  transform: translateY(-2px);
  box-shadow: 0 8px 28px rgba(0,0,0,0.5);
}
.tut-callout__stats {
  display: flex;
  flex-direction: column;
  gap: 1rem;
}
.tut-callout__stat {
  background: rgba(0,0,0,0.22);
  border: 1px solid rgba(255,255,255,0.15);
  border-radius: var(--radius-lg);
  padding: 1.1rem 1.6rem;
  min-width: 180px;
  backdrop-filter: blur(8px);
  transition: background 200ms, border-color 200ms;
}
.tut-callout__stat:hover {
  background: rgba(0,0,0,0.35);
  border-color: rgba(255,255,255,0.28);
}
.tut-callout__stat-val {
  font-family: var(--font-serif);
  font-size: 1.9rem;
  font-weight: 800;
  color: #ffffff;
  line-height: 1;
  margin-bottom: 0.3rem;
}
.tut-callout__stat-lbl {
  font-size: 0.75rem;
  color: rgba(255,255,255,0.6);
  letter-spacing: 0.03em;
}

/* === FSH CALLOUT (homepage banner) === */
.fsh-callout {
  background: var(--surface);
  position: relative;
  overflow: hidden;
  padding: 5.5rem 0;
}
.fsh-callout::before {
  content: '';
  position: absolute;
  inset: 0;
  background:
    radial-gradient(ellipse 70% 90% at 0% 50%, rgba(200,150,60,0.13) 0%, transparent 65%),
    radial-gradient(ellipse 50% 60% at 100% 30%, rgba(200,150,60,0.07) 0%, transparent 60%);
  pointer-events: none;
}
.fsh-callout__inner {
  display: flex;
  align-items: center;
  gap: 3.5rem;
  flex-wrap: wrap;
  position: relative;
  z-index: 1;
}
.fsh-callout__content {
  flex: 1;
  min-width: 280px;
}
.fsh-callout__eyebrow {
  display: inline-block;
  font-size: 0.72rem;
  font-weight: 700;
  letter-spacing: 0.15em;
  text-transform: uppercase;
  color: var(--accent);
  margin-bottom: 0.75rem;
}
.fsh-callout__title {
  font-family: var(--font-serif);
  font-size: clamp(2.2rem, 4vw, 3.2rem);
  font-weight: 700;
  color: var(--text);
  line-height: 1.1;
  margin-bottom: 1rem;
  letter-spacing: -0.01em;
}
.fsh-callout__title span { color: var(--accent); }
.fsh-callout__desc {
  color: var(--text-secondary);
  max-width: 460px;
  margin-bottom: 1.75rem;
  line-height: 1.75;
  font-size: 0.97rem;
}
.fsh-callout__badges {
  display: flex;
  gap: 0.875rem;
  flex-wrap: wrap;
  margin-bottom: 2rem;
}
.fsh-callout__badge {
  background: var(--bg);
  border: 1px solid var(--border);
  border-radius: var(--radius-md);
  padding: 0.7rem 1.1rem;
  min-width: 80px;
  text-align: center;
  transition: border-color var(--transition);
}
.fsh-callout__badge:hover { border-color: var(--accent); }
.fsh-callout__badge-val {
  font-family: var(--font-serif);
  font-size: 1.4rem;
  font-weight: 700;
  color: var(--accent);
  line-height: 1;
}
.fsh-callout__badge-lbl {
  font-size: 0.7rem;
  color: var(--text-muted);
  margin-top: 0.25rem;
  letter-spacing: 0.02em;
}
/* code editor window */
.fsh-callout__window {
  flex: 1;
  min-width: 300px;
  max-width: 500px;
  background: #0d1117;
  border: 1px solid #30363d;
  border-radius: var(--radius-lg);
  overflow: hidden;
  box-shadow:
    var(--shadow-lg),
    0 0 0 1px rgba(200,150,60,0.15),
    0 0 50px rgba(200,150,60,0.08);
}
.fsh-window-bar {
  display: flex;
  align-items: center;
  gap: 0.4rem;
  padding: 0.625rem 1rem;
  background: #161b22;
  border-bottom: 1px solid #30363d;
}
.fsh-dot {
  width: 11px;
  height: 11px;
  border-radius: 50%;
  flex-shrink: 0;
}
.fsh-dot--r { background: #ff5f57; }
.fsh-dot--y { background: #febc2e; }
.fsh-dot--g { background: #28c840; }
.fsh-window-bar__name {
  font-family: var(--font-mono);
  font-size: 0.72rem;
  color: #8b949e;
  margin-left: 0.5rem;
}
.fsh-window-body {
  margin: 0;
  padding: 1.25rem 1.5rem;
  background: #0d1117;
  border: none;
  border-radius: 0;
  font-size: 0.8rem;
  line-height: 1.75;
  overflow-x: auto;
}
/* FSH syntax tokens */
.fsh-kw   { color: #ff7b72; }
.fsh-val  { color: #79c0ff; }
.fsh-id   { color: #d2a8ff; }
.fsh-str  { color: #a5d6ff; }
.fsh-card { color: #f2cc60; }
.fsh-flag { color: #c8963c; }
.fsh-bullet { color: #8b949e; }
.fsh-url  { color: #79c0ff; }

/* === CONTACT === */
.contact { background: var(--surface); }
.contact__inner { display: grid; grid-template-columns: 1fr 1fr; gap: 4rem; align-items: start; }
.contact__desc { color: var(--text-secondary); margin-bottom: 2rem; font-size: 0.97rem; }
.contact__links { display: flex; flex-direction: column; gap: 0.65rem; }
.contact__link {
  display: flex; align-items: center; gap: 0.85rem;
  padding: 0.8rem 1rem; background: var(--bg); border: 1px solid var(--border);
  border-radius: var(--radius-md); color: var(--text); transition: all var(--transition);
}
.contact__link:hover { border-color: var(--accent); background: var(--accent-light); color: var(--accent); transform: translateX(4px); }
.contact__link-icon {
  width: 36px; height: 36px; background: var(--accent-warm-light);
  border-radius: var(--radius-sm); display: flex; align-items: center; justify-content: center; font-size: 1rem; flex-shrink: 0;
}
.contact__link-label { font-size: 0.7rem; color: var(--text-muted); margin-bottom: 0.1rem; }
.contact__link-text { font-size: 0.88rem; }

/* === FOOTER === */
.footer { background: var(--surface); color: rgba(255,255,255,0.65); padding: 3rem 0 1.5rem; border-top: 1px solid var(--border); }
.footer__inner { display: flex; justify-content: space-between; align-items: flex-start; flex-wrap: wrap; gap: 2.5rem; margin-bottom: 2.5rem; }
.footer__logo { font-family: var(--font-serif); font-size: 1.15rem; color: white; margin-bottom: 0.3rem; font-weight: 600; }
.footer__tagline { font-size: 0.78rem; color: rgba(255,255,255,0.4); max-width: 320px; line-height: 1.5; }
.footer__socials { display: flex; gap: 1rem; margin-top: 1.1rem; }
.footer__social-link {
  color: rgba(255,255,255,0.35); transition: color var(--transition);
  display: flex; align-items: center;
}
.footer__social-link:hover { color: var(--accent); }
.footer__links { display: flex; flex-direction: column; gap: 0.6rem; align-items: flex-end; }
.footer__link { color: rgba(255,255,255,0.45); font-size: 0.82rem; transition: color var(--transition); }
.footer__link:hover { color: white; }
.footer__copyright { text-align: center; font-size: 0.73rem; color: rgba(255,255,255,0.25); padding-top: 1.5rem; border-top: 1px solid rgba(255,255,255,0.08); }

/* === BACK TO TOP === */
.back-to-top {
  position: fixed; bottom: 1.5rem; right: 1.5rem; z-index: 50;
  width: 40px; height: 40px; background: var(--accent); color: white;
  border: none; border-radius: 50%; cursor: pointer;
  display: flex; align-items: center; justify-content: center;
  box-shadow: var(--shadow-md); opacity: 0; transform: translateY(10px);
  pointer-events: none; transition: all var(--transition);
}
.back-to-top.visible { opacity: 1; transform: translateY(0); pointer-events: auto; }
.back-to-top:hover { background: var(--accent-warm); transform: translateY(-2px); }

/* === REVEAL ANIMATIONS === */
.reveal { opacity: 0; transform: translateY(20px); transition: opacity 0.6s ease, transform 0.6s ease; }
.reveal.visible { opacity: 1; transform: translateY(0); }
.reveal-d1 { transition-delay: 0.1s; }
.reveal-d2 { transition-delay: 0.2s; }
.reveal-d3 { transition-delay: 0.3s; }
.reveal-d4 { transition-delay: 0.4s; }

/* =====================================================
   BLOG PAGES
   ===================================================== */
.blog-hero {
  padding-top: calc(var(--nav-height) + 3rem); padding-bottom: 2.5rem;
  background: var(--surface); border-bottom: 1px solid var(--border);
}
.post-cat {
  display: inline-block; font-size: 0.72rem; font-weight: 700;
  letter-spacing: 0.12em; text-transform: uppercase; color: var(--accent-warm); margin-bottom: 1rem;
}
.post-title { font-size: clamp(1.7rem, 4vw, 2.7rem); line-height: 1.2; margin-bottom: 1rem; max-width: 800px; }
.post-meta { display: flex; flex-wrap: wrap; gap: 1rem; font-size: 0.83rem; color: var(--text-muted); align-items: center; }
.post-meta-item { display: flex; align-items: center; gap: 0.3rem; }

.post-img { width: 100%; max-height: 420px; object-fit: cover; border-radius: var(--radius-lg); margin: 2rem 0; box-shadow: var(--shadow-md); }

.post-body { padding: 2.5rem 0 5rem; }
.post-body__inner { max-width: 720px; margin: 0 auto; padding: 0 1.5rem; }
.post-body__inner h2 { font-size: 1.55rem; margin: 2rem 0 0.7rem; padding-bottom: 0.45rem; border-bottom: 2px solid var(--border); }
.post-body__inner h3 { font-size: 1.25rem; color: var(--accent); margin: 1.5rem 0 0.5rem; }
.post-body__inner h4 { font-size: 1.05rem; margin: 1.25rem 0 0.4rem; }
.post-body__inner p { color: var(--text-secondary); line-height: 1.8; margin-bottom: 1.2rem; }
.post-body__inner ul, .post-body__inner ol { padding-left: 1.5rem; margin-bottom: 1.2rem; color: var(--text-secondary); }
.post-body__inner ul { list-style: disc; }
.post-body__inner ol { list-style: decimal; }
.post-body__inner li { margin-bottom: 0.4rem; line-height: 1.65; }
.post-body__inner blockquote {
  margin: 1.5rem 0; padding: 1rem 1.4rem;
  border-left: 4px solid var(--accent-warm);
  background: var(--accent-warm-light); border-radius: 0 var(--radius-md) var(--radius-md) 0;
  font-style: italic; color: var(--text);
}
.post-body__inner a { text-decoration: underline; text-underline-offset: 3px; }
.post-body__inner img { border-radius: var(--radius-md); margin: 1.5rem 0; box-shadow: var(--shadow-md); }

.ref-box {
  background: var(--surface); border: 1px solid var(--border); border-radius: var(--radius-md);
  padding: 1rem 1.2rem; margin: 1.2rem 0; font-size: 0.875rem; color: var(--text-secondary);
}
.ref-box cite { font-style: normal; font-weight: 600; color: var(--text); }

.author-box {
  background: var(--surface); border: 1px solid var(--border); border-radius: var(--radius-lg);
  padding: 1.5rem; display: flex; gap: 1.2rem; align-items: flex-start; margin-top: 3rem;
}
.author-box__avatar { width: 60px; height: 60px; border-radius: 50%; object-fit: cover; flex-shrink: 0; object-position: top; }
.author-box__name { font-weight: 600; margin-bottom: 0.2rem; }
.author-box__desc { font-size: 0.85rem; color: var(--text-secondary); margin-bottom: 0.65rem; }
.author-box__links { display: flex; gap: 0.7rem; }
.author-box__links a { font-size: 0.8rem; color: var(--text-muted); }
.author-box__links a:hover { color: var(--accent); }

.post-nav { display: grid; grid-template-columns: 1fr 1fr; gap: 1rem; margin-top: 2rem; padding-top: 2rem; border-top: 1px solid var(--border); }
.post-nav__item { padding: 1rem; background: var(--surface); border: 1px solid var(--border); border-radius: var(--radius-md); transition: all var(--transition); }
.post-nav__item:hover { border-color: var(--accent); background: var(--accent-light); }
.post-nav__lbl { font-size: 0.7rem; font-weight: 700; letter-spacing: 0.08em; text-transform: uppercase; color: var(--text-muted); margin-bottom: 0.25rem; }
.post-nav__title { font-family: var(--font-serif); font-size: 0.92rem; color: var(--text); }
.post-nav__item--next { text-align: right; }

/* === BLOG LISTING PAGE === */
.blog-index-hero { padding-top: calc(var(--nav-height) + 3rem); padding-bottom: 2rem; background: var(--surface); border-bottom: 1px solid var(--border); }
.blog-filter { display: flex; flex-wrap: wrap; gap: 0.45rem; margin-bottom: 2.5rem; }
.blog-filter__btn {
  padding: 0.38rem 0.95rem; border-radius: 100px; font-size: 0.8rem; font-weight: 500;
  background: var(--surface); color: var(--text-secondary); border: 1px solid var(--border);
  cursor: pointer; transition: all var(--transition);
}
.blog-filter__btn:hover { border-color: var(--accent); color: var(--accent); }
.blog-filter__btn.active { background: var(--accent); color: white; border-color: var(--accent); }

/* =====================================================
   FSH TUTORIAL — CARD NAVIGATION
   ===================================================== */
.tut-page { padding: calc(var(--nav-height) + 2.5rem) 0 5rem; }

.tut-header { text-align: center; max-width: 700px; margin: 0 auto 3rem; padding: 0 1.5rem; }
.tut-header__cover { width: 100%; max-height: 300px; object-fit: contain; border-radius: var(--radius-lg); margin-bottom: 2rem; }
.tut-header__title { font-size: clamp(1.6rem, 3.5vw, 2.3rem); margin-bottom: 0.6rem; }
.tut-header__meta { font-size: 0.82rem; color: var(--text-muted); margin-bottom: 1.5rem; }
.tut-header__actions { display: flex; justify-content: center; flex-wrap: wrap; gap: 0.75rem; }

.tut-cards-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(270px, 1fr));
  gap: 1.25rem;
  padding: 0 1.5rem;
  max-width: var(--max-width);
  margin: 0 auto;
}

.tut-card {
  background: var(--bg); border: 1px solid var(--border); border-radius: var(--radius-lg);
  padding: 1.5rem 1.5rem 1.25rem;
  cursor: pointer; transition: all var(--transition);
  display: flex; flex-direction: column; gap: 0.5rem;
  position: relative; overflow: hidden;
  text-align: left;
}
.tut-card::before {
  content: ''; position: absolute; bottom: 0; left: 0; right: 0; height: 3px;
  background: linear-gradient(90deg, var(--accent), var(--accent-warm));
  transform: scaleX(0); transform-origin: left; transition: transform var(--transition);
}
.tut-card:hover { box-shadow: var(--shadow-md); transform: translateY(-3px); border-color: var(--accent); }
.tut-card:hover::before { transform: scaleX(1); }
.tut-card--highlight { background: var(--accent); border-color: var(--accent); color: white; }
.tut-card--highlight::before { display: none; }
.tut-card--highlight:hover { background: var(--accent-hover); }
.tut-card--highlight .tut-card__num, .tut-card--highlight .tut-card__desc { color: rgba(255,255,255,0.75); }
.tut-card--highlight .tut-card__title { color: white; }

.tut-card__icon { font-size: 1.75rem; }
.tut-card__num { font-size: 0.68rem; font-weight: 700; letter-spacing: 0.12em; text-transform: uppercase; color: var(--accent-warm); }
.tut-card__title { font-family: var(--font-serif); font-size: 1.15rem; font-weight: 600; line-height: 1.25; color: #ffffff; }
.tut-card__desc { font-size: 0.82rem; color: var(--text-secondary); line-height: 1.5; flex: 1; }
.tut-card__arrow { align-self: flex-end; font-size: 0.9rem; color: var(--accent-warm); margin-top: 0.5rem; }
.tut-card--highlight .tut-card__arrow { color: var(--accent-warm); }

/* Section view */
.tut-section-view { display: none; max-width: 760px; margin: 0 auto; padding: 0 1.5rem; }
.tut-section-view.active { display: block; animation: fadeIn 0.3s ease; }

.tut-back {
  display: inline-flex; align-items: center; gap: 0.4rem;
  font-size: 0.82rem; color: var(--text-muted); cursor: pointer;
  padding: 0.4rem 0.8rem; border: 1px solid var(--border); border-radius: 100px;
  background: var(--surface); transition: all var(--transition); margin-bottom: 2rem;
  font-family: var(--font-sans);
}
.tut-back:hover { color: var(--accent); border-color: var(--accent); background: var(--accent-light); }

.tut-section-view h2 { font-size: 1.7rem; margin-bottom: 0.5rem; }
.tut-section-view h3 { font-size: 1.2rem; color: var(--accent); margin: 1.5rem 0 0.5rem; }
.tut-section-view h4 { font-size: 0.95rem; font-weight: 600; margin: 1.2rem 0 0.35rem; }
.tut-section-view p { color: var(--text-secondary); line-height: 1.78; margin-bottom: 1.1rem; }
.tut-section-view ul, .tut-section-view ol { padding-left: 1.5rem; margin-bottom: 1rem; color: var(--text-secondary); }
.tut-section-view ul { list-style: disc; }
.tut-section-view ol { list-style: decimal; }
.tut-section-view li { margin-bottom: 0.4rem; line-height: 1.65; }
.tut-section-view a { text-decoration: underline; text-underline-offset: 3px; }
.tut-section-view blockquote {
  font-style: italic; color: var(--accent); border-left: 3px solid var(--accent-warm);
  padding-left: 1.2rem; margin: 1.25rem 0;
}

.tut-section-img { width: 100%; border-radius: var(--radius-md); margin: 1.25rem 0; box-shadow: var(--shadow-md); border: 1px solid var(--border); }
.tut-section-img-caption { text-align: center; font-size: 0.78rem; color: var(--text-muted); margin-top: -0.75rem; margin-bottom: 1.25rem; font-style: italic; }

.tut-nav {
  display: flex; justify-content: space-between; align-items: center;
  margin-top: 3rem; padding-top: 2rem; border-top: 1px solid var(--border);
  flex-wrap: wrap; gap: 1rem;
}
.tut-nav__btn {
  display: inline-flex; align-items: center; gap: 0.4rem;
  padding: 0.55rem 1rem; border-radius: var(--radius-md);
  border: 1px solid var(--border); background: var(--surface);
  font-size: 0.82rem; font-weight: 500; cursor: pointer;
  transition: all var(--transition); font-family: var(--font-sans); color: var(--text);
}
.tut-nav__btn:hover { border-color: var(--accent); background: var(--accent-light); color: var(--accent); }
.tut-nav__btn--primary { background: var(--accent); color: white; border-color: var(--accent); }
.tut-nav__btn--primary:hover { background: var(--accent-hover); color: white; }

/* Exercise sub-cards */
.ex-cards { display: grid; grid-template-columns: repeat(auto-fill, minmax(220px, 1fr)); gap: 1rem; margin: 1.5rem 0; }
.ex-card {
  background: var(--bg); border: 1px solid var(--border); border-radius: var(--radius-md);
  padding: 1.25rem; cursor: pointer; transition: all var(--transition);
}
.ex-card:hover { border-color: var(--accent); box-shadow: var(--shadow-md); transform: translateY(-2px); }
.ex-card__num { font-size: 0.7rem; font-weight: 700; letter-spacing: 0.1em; text-transform: uppercase; color: var(--accent-warm); margin-bottom: 0.3rem; }
.ex-card__title { font-family: var(--font-serif); font-size: 0.98rem; }

/* FSH TUTORIAL — OLD LAYOUT (kept for backward compat if needed) === */
.tut-layout {
  display: grid; grid-template-columns: 260px 1fr; gap: 3rem;
  max-width: var(--max-width); margin: 0 auto;
  padding: calc(var(--nav-height) + 2.5rem) 1.5rem 5rem;
}

.tut-toc {
  position: sticky; top: calc(var(--nav-height) + 1.5rem);
  height: fit-content; max-height: calc(100vh - var(--nav-height) - 3rem);
  overflow-y: auto;
}
.tut-toc__title { font-size: 0.7rem; font-weight: 700; letter-spacing: 0.12em; text-transform: uppercase; color: var(--text-muted); margin-bottom: 0.65rem; }
.tut-toc__list { list-style: none; padding: 0; }
.tut-toc__item { margin-bottom: 0.2rem; }
.tut-toc__link {
  display: block; padding: 0.28rem 0.6rem; font-size: 0.8rem;
  color: var(--text-secondary); border-left: 2px solid var(--border);
  transition: all var(--transition);
}
.tut-toc__link:hover, .tut-toc__link.active { color: var(--accent); border-left-color: var(--accent); background: var(--accent-light); }
.tut-toc__link--sub { padding-left: 1.2rem; font-size: 0.76rem; }

.tut-content h2 {
  font-size: 1.75rem; border-bottom: 2px solid var(--border);
  padding-bottom: 0.45rem; margin: 2.5rem 0 1rem;
}
.tut-content h2:first-child { margin-top: 0; }
.tut-content h3 { font-size: 1.25rem; color: var(--accent); margin: 1.75rem 0 0.55rem; }
.tut-content h4 { font-size: 1rem; margin: 1.2rem 0 0.4rem; }
.tut-content p { color: var(--text-secondary); line-height: 1.78; margin-bottom: 1.1rem; }
.tut-content ul, .tut-content ol { padding-left: 1.5rem; margin-bottom: 1rem; color: var(--text-secondary); }
.tut-content ul { list-style: disc; }
.tut-content ol { list-style: decimal; }
.tut-content li { margin-bottom: 0.4rem; line-height: 1.65; }
.tut-content a { text-decoration: underline; text-underline-offset: 3px; }

.exercise {
  background: var(--surface); border: 1px solid var(--border);
  border-radius: var(--radius-lg); margin: 2rem 0; overflow: hidden;
}
.exercise__header {
  background: var(--accent); color: white; padding: 0.9rem 1.4rem;
  display: flex; align-items: center; gap: 0.7rem;
}
.exercise__num {
  background: var(--accent-warm); color: white; width: 26px; height: 26px;
  border-radius: 50%; display: flex; align-items: center; justify-content: center;
  font-size: 0.82rem; font-weight: 700; flex-shrink: 0;
}
.exercise__title { font-family: var(--font-sans); font-size: 0.92rem; font-weight: 600; }
.exercise__body { padding: 1.4rem; }
.exercise__body p { font-size: 0.88rem; color: var(--text-secondary); margin-bottom: 0.7rem; }
.exercise__body h4 { font-size: 0.75rem; font-weight: 700; letter-spacing: 0.1em; text-transform: uppercase; color: var(--text-muted); margin: 0.9rem 0 0.35rem; }

.code-wrap { position: relative; margin: 0.75rem 0; }
.code-copy {
  position: absolute; top: 0.5rem; right: 0.5rem;
  background: rgba(255,255,255,0.1); border: 1px solid rgba(255,255,255,0.2);
  color: rgba(255,255,255,0.7); padding: 0.22rem 0.55rem;
  border-radius: var(--radius-sm); font-size: 0.68rem; cursor: pointer;
  transition: all var(--transition); font-family: var(--font-sans);
}
.code-copy:hover { background: rgba(255,255,255,0.2); color: white; }

.sol-links { display: flex; flex-wrap: wrap; gap: 0.45rem; margin-top: 0.7rem; }
.sol-link {
  display: inline-flex; align-items: center; gap: 0.3rem;
  background: var(--accent-warm-light); color: var(--accent-warm); border: 1px solid rgba(245,158,11,0.35);
  padding: 0.28rem 0.65rem; border-radius: 100px; font-size: 0.75rem; font-weight: 500;
  transition: all var(--transition);
}
.sol-link:hover { background: var(--accent-warm); color: white; border-color: var(--accent-warm); }

.info-box {
  background: var(--accent-light); border: 1px solid rgba(200,150,60,0.4);
  border-radius: var(--radius-md); padding: 0.9rem 1.15rem;
  margin: 1rem 0; font-size: 0.875rem; color: var(--accent);
}
.info-box strong { display: block; margin-bottom: 0.2rem; }

.concepts {
  background: var(--accent-warm-light); border: 1px solid rgba(245,158,11,0.35);
  border-radius: var(--radius-md); padding: 0.9rem 1.15rem; margin: 0.75rem 0;
}
.concepts h4 { font-size: 0.72rem; font-weight: 700; letter-spacing: 0.1em; text-transform: uppercase; color: var(--accent-warm); margin-bottom: 0.45rem; }
.concepts li { font-size: 0.83rem; color: rgba(245,158,11,0.85); padding: 0.18rem 0; display: flex; align-items: center; gap: 0.45rem; list-style: none; }
.concepts li::before { content: '✓'; color: var(--accent-warm); font-weight: 700; }

/* =====================================================
   RESPONSIVE
   ===================================================== */
@media (max-width: 960px) {
  .hero__inner { grid-template-columns: 1fr; text-align: center; }
  .hero__img-wrapper { order: -1; max-width: 260px; margin: 0 auto; }
  .hero__bio, .hero__cta, .hero__stats { justify-content: center; }
  .hero__bio { margin: 0 auto 1.75rem; }
  .contact__inner { grid-template-columns: 1fr; }
  .tut-layout { grid-template-columns: 1fr; }
  .tut-toc { display: none; }
  .expertise-grid { grid-template-columns: repeat(2, 1fr); }
}

@media (max-width: 480px) {
  .expertise-grid { grid-template-columns: 1fr; }
}

@media (max-width: 768px) {
  :root { --space-section: 3.5rem; }
  section { padding: 3.5rem 0; }
  .nav__links, .nav__social { display: none; }
  .nav__hamburger { display: flex; }
  .blog-grid, .projects__grid { grid-template-columns: 1fr; }
  .post-nav { grid-template-columns: 1fr; }
  .footer__inner { flex-direction: column; gap: 1.5rem; }
}

@media (max-width: 480px) {
  .hero__stats { flex-direction: column; align-items: center; gap: 1rem; }
  .hero__cta { flex-direction: column; align-items: center; }
  .tut-layout { padding-left: 1rem; padding-right: 1rem; }
  .expertise-grid { grid-template-columns: 1fr; }
}