/* ============================================================
   Badreddine Barki — Portfolio
   Minimalist design · Century Gothic · light palette
   ============================================================ */

:root {
  --bg: #e9e9e6;
  --bg-alt: #dededa;
  --surface: #f5f5f3;
  --border: #cfcfc9;
  --border-strong: #b7b7b0;
  --text: #000000;
  --text-dim: #000000;
  --text-muted: #000000;
  --accent: #000000;
  --accent-soft: #e2e2de;
  --radius: 2px;
  --radius-md: 4px;
  --font: "Century Gothic", CenturyGothic, AppleGothic, "Futura", "Trebuchet MS", "Segoe UI", sans-serif;
  --max: 1080px;
  --nav-h: 64px;
  --sidebar-w: 236px;
  --ease: 0.2s ease;
}

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

html {
  /* Smooth scrolling is handled in JS (main.js) with a gentle,
     distance-aware easing so long in-page jumps aren't jarring.
     scroll-padding-top keeps section headings clear of the sticky nav
     for keyboard focus and any native (non-JS) jumps. */
  scroll-padding-top: calc(var(--nav-h) + 16px);
}

@media (prefers-reduced-motion: reduce) {
  html { scroll-behavior: auto; }
}

body {
  font-family: var(--font);
  background: var(--bg);
  color: var(--text);
  line-height: 1.7;
  font-size: 16px;
  letter-spacing: 0.01em;
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
  position: relative;
}

/* Soft ambient glow breaking up the flat grey backdrop */
body::before {
  content: "";
  position: fixed;
  inset: 0;
  z-index: -1;
  background:
    radial-gradient(ellipse 900px 560px at 12% -8%, rgba(255, 255, 255, 0.85), transparent 62%),
    radial-gradient(ellipse 800px 620px at 108% 18%, rgba(255, 255, 255, 0.55), transparent 58%),
    radial-gradient(ellipse 900px 700px at 50% 120%, rgba(255, 255, 255, 0.4), transparent 60%),
    var(--bg);
  pointer-events: none;
}

img { max-width: 100%; display: block; }
a { color: var(--text); text-decoration: none; border-bottom: 1px solid transparent; transition: border-color var(--ease), color var(--ease); }
a:hover { border-bottom-color: var(--text); }
ul { list-style: none; }

.container {
  width: min(var(--max), 90%);
  margin: 0 auto;
}

/* ---------- Buttons ---------- */
.btn {
  display: inline-block;
  padding: 0.7rem 1.4rem;
  border-radius: var(--radius);
  font-family: var(--font);
  font-weight: 400;
  font-size: 0.85rem;
  letter-spacing: 0.06em;
  text-transform: uppercase;
  border: 1px solid var(--text);
  cursor: pointer;
  transition: background var(--ease), color var(--ease), border-color var(--ease);
  border-bottom: 1px solid var(--text);
}
.btn:hover { text-decoration: none; border-bottom-color: var(--text); }
.btn--primary {
  background: var(--text);
  color: #fff;
}
.btn--primary:hover {
  background: #333;
  border-color: #333;
  color: #fff;
}
.btn--ghost {
  background: transparent;
  color: var(--text);
}
.btn--ghost:hover {
  background: var(--accent-soft);
}

/* ---------- Navigation (vertical sidebar) ----------
   The primary nav is a fixed vertical column on the left for desktop.
   On small screens it collapses into a top bar + slide-in drawer
   (handled in the responsive block further down). */
.nav {
  position: fixed;
  inset: 0 auto 0 0;
  z-index: 100;
  width: var(--sidebar-w);
  height: 100vh;
  background: rgba(233, 233, 230, 0.92);
  backdrop-filter: blur(10px);
  -webkit-backdrop-filter: blur(10px);
  border-right: 1px solid var(--border);
  transition: border-color var(--ease);
}

.nav__inner {
  display: flex;
  flex-direction: column;
  align-items: stretch;
  height: 100%;
  width: 100%;
  margin: 0;
  padding: 2rem 1.6rem;
  gap: 2rem;
}

.nav__logo {
  font-size: 1.15rem;
  font-weight: 400;
  letter-spacing: 0.12em;
  text-transform: uppercase;
  color: var(--text);
  border-bottom: none;
  flex-shrink: 0;
}
.nav__logo span {
  font-weight: 700;
  margin: 0 0.05em;
}
.nav__logo:hover { border-bottom: none; }

.nav__links {
  display: flex;
  flex-direction: column;
  align-items: stretch;
  gap: 0.25rem;
  flex: 1;
}
.nav__links a {
  color: var(--text-dim);
  font-size: 0.82rem;
  letter-spacing: 0.08em;
  text-transform: uppercase;
  border-bottom: none;
  border-left: 2px solid transparent;
  padding: 0.55rem 0 0.55rem 0.85rem;
  transition: color var(--ease), border-color var(--ease), background var(--ease);
}
.nav__links a:hover,
.nav__links a.active {
  color: var(--text);
  border-left-color: var(--text);
  background: var(--accent-soft);
  text-decoration: none;
}
.nav__cta {
  margin-top: auto;
  text-align: center;
  padding: 0.6rem 0.9rem !important;
  border: 1px solid var(--text) !important;
  color: var(--text) !important;
  letter-spacing: 0.08em;
  border-left: 1px solid var(--text) !important;
}
.nav__cta:hover,
.nav__cta.active {
  background: var(--text) !important;
  color: #fff !important;
  border-color: var(--text) !important;
}

/* ---- Language switcher ---- */
.nav__lang {
  display: flex;
  gap: 0.4rem;
  align-items: center;
  padding-left: 0.85rem;
  margin-top: 1rem;
}
.nav__lang a {
  font-size: 0.72rem;
  letter-spacing: 0.1em;
  text-transform: uppercase;
  color: var(--text-dim);
  border: 1px solid var(--border);
  border-left: 1px solid var(--border);
  padding: 0.3rem 0.6rem;
  transition: color var(--ease), border-color var(--ease), background var(--ease);
}
.nav__lang a:hover {
  color: var(--text);
  border-color: var(--text);
  text-decoration: none;
}
.nav__lang a.active {
  color: #fff;
  background: var(--text);
  border-color: var(--text);
}

.nav__toggle {
  display: none;
  flex-direction: column;
  gap: 5px;
  background: none;
  border: none;
  cursor: pointer;
  padding: 6px;
}
.nav__toggle span {
  width: 22px;
  height: 1px;
  background: var(--text);
  transition: transform 0.25s ease, opacity 0.25s ease;
}
.nav__toggle.open span:nth-child(1) { transform: translateY(6px) rotate(45deg); }
.nav__toggle.open span:nth-child(2) { opacity: 0; }
.nav__toggle.open span:nth-child(3) { transform: translateY(-6px) rotate(-45deg); }

/* Shift all page content clear of the fixed sidebar on desktop. */
body {
  padding-left: var(--sidebar-w);
}

/* ---------- Hero ---------- */
.hero {
  min-height: 100vh;
  display: flex;
  align-items: center;
  padding: 80px 0;
  background: var(--bg);
}
.hero__inner {
  display: grid;
  grid-template-columns: 1fr;
  align-items: center;
}
.hero__kicker {
  color: var(--text-muted);
  font-weight: 400;
  letter-spacing: 0.14em;
  text-transform: uppercase;
  font-size: 0.72rem;
  margin-bottom: 1.4rem;
}
.hero__title {
  font-size: clamp(2.4rem, 5.5vw, 3.6rem);
  font-weight: 400;
  line-height: 1.1;
  letter-spacing: -0.01em;
  margin-bottom: 1.4rem;
  color: var(--text);
}
.hero__title span {
  font-weight: 700;
}
.hero__subtitle {
  color: var(--text-dim);
  font-size: 1rem;
  max-width: 48ch;
  margin-bottom: 2rem;
  line-height: 1.75;
}
.hero__subtitle strong {
  color: var(--text);
  font-weight: 600;
}
.hero__actions {
  display: flex;
  flex-wrap: wrap;
  gap: 0.75rem;
  margin-bottom: 3rem;
}
.hero__stats {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 1.5rem;
  padding-top: 2rem;
  border-top: 1px solid var(--border);
}
.hero__stats li {
  display: flex;
  flex-direction: column;
  gap: 0.3rem;
}
.hero__stats strong {
  font-size: 1.5rem;
  font-weight: 400;
  letter-spacing: -0.02em;
  color: var(--text);
}
.hero__stats span {
  color: var(--text-muted);
  font-size: 0.72rem;
  letter-spacing: 0.04em;
  text-transform: uppercase;
  line-height: 1.4;
  max-width: 14ch;
}
/* ---------- Sections ---------- */
.section {
  padding: 100px 0;
}
.section--alt {
  background: var(--bg-alt);
}
.section__title {
  font-size: clamp(1.5rem, 3vw, 1.85rem);
  font-weight: 400;
  letter-spacing: 0.04em;
  text-transform: uppercase;
  margin-bottom: 0.75rem;
  color: var(--text);
}
.section__title::after {
  content: "";
  display: block;
  width: 32px;
  height: 1px;
  background: var(--text);
  margin-top: 0.85rem;
}
.section__lead {
  color: var(--text-dim);
  max-width: 62ch;
  margin: 1.25rem 0 2.75rem;
  font-size: 0.98rem;
}
.section__lead strong { color: var(--text); font-weight: 600; }

/* ---------- About ---------- */
.about__grid {
  display: grid;
  grid-template-columns: 1.55fr 1fr;
  gap: 3.5rem;
  margin-top: 2.5rem;
}
.about__text p {
  color: var(--text-dim);
  margin-bottom: 1.15rem;
  font-size: 0.98rem;
}
.about__text strong { color: var(--text); font-weight: 600; }

.about__facts {
  border: 1px solid var(--border);
  background: var(--surface);
  padding: 1.75rem 1.6rem;
  height: fit-content;
}
.about__facts h3 {
  font-size: 0.75rem;
  font-weight: 400;
  letter-spacing: 0.12em;
  text-transform: uppercase;
  margin-bottom: 1.25rem;
  color: var(--text-muted);
}
.about__facts li {
  display: flex;
  justify-content: space-between;
  gap: 1rem;
  padding: 0.65rem 0;
  border-bottom: 1px solid var(--border);
  font-size: 0.88rem;
}
.about__facts li:last-child { border-bottom: none; }
.about__facts span { color: var(--text-muted); }
.about__facts strong {
  text-align: right;
  font-weight: 400;
  color: var(--text);
}
.about__facts a {
  color: var(--text);
  border-bottom: 1px solid var(--border-strong);
}
.about__facts a:hover { border-bottom-color: var(--text); }

/* ---------- Career path (experience) ---------- */
.career {
  margin-top: 1rem;
  display: flex;
  flex-direction: column;
  gap: 0;
}

.career__role {
  display: grid;
  grid-template-columns: 72px 1fr;
  gap: 0 1.75rem;
  align-items: stretch;
}

.career__rail {
  display: flex;
  flex-direction: column;
  align-items: center;
  padding-top: 0.35rem;
}

.career__index {
  font-size: 0.75rem;
  letter-spacing: 0.14em;
  color: var(--text-muted);
  font-weight: 400;
  line-height: 1;
  flex-shrink: 0;
}

.career__spine {
  flex: 1;
  width: 1px;
  background: linear-gradient(to bottom, var(--border-strong), var(--border));
  margin-top: 0.85rem;
  min-height: 2rem;
}

.career__body {
  padding-bottom: 3.25rem;
  border-bottom: 1px solid var(--border);
  margin-bottom: 2.75rem;
}

.career__role:last-child .career__body {
  border-bottom: none;
  margin-bottom: 0;
  padding-bottom: 0;
}

.career__header {
  display: flex;
  flex-wrap: wrap;
  justify-content: space-between;
  align-items: flex-start;
  gap: 1.25rem 2rem;
  margin-bottom: 1.1rem;
}

.career__meta {
  display: flex;
  flex-direction: column;
  gap: 0.25rem;
}

.career__years {
  font-size: 0.78rem;
  letter-spacing: 0.1em;
  text-transform: uppercase;
  color: var(--text);
}

.career__duration {
  font-size: 0.72rem;
  letter-spacing: 0.06em;
  color: var(--text-muted);
}

.career__brand {
  display: flex;
  align-items: center;
  gap: 0.85rem;
  text-align: right;
}

.career__monogram {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  min-width: 56px;
  width: 56px;
  height: 56px;
  padding: 0.5rem;
  border: 1px solid var(--border);
  font-size: 0.72rem;
  letter-spacing: 0.08em;
  font-weight: 600;
  color: var(--text);
  background: #fff;
  flex-shrink: 0;
}
.career__monogram img {
  max-width: 100%;
  max-height: 100%;
  width: auto;
  height: auto;
  object-fit: contain;
}

.career__company {
  font-size: 0.95rem;
  font-weight: 600;
  color: var(--text);
  line-height: 1.3;
}

.career__place {
  font-size: 0.78rem;
  color: var(--text-muted);
  letter-spacing: 0.03em;
}

.career__title {
  font-size: clamp(1.2rem, 2.5vw, 1.45rem);
  font-weight: 400;
  letter-spacing: 0.01em;
  line-height: 1.3;
  margin-bottom: 0.65rem;
}

.career__summary {
  color: var(--text-dim);
  font-size: 0.95rem;
  max-width: 62ch;
  margin-bottom: 1.5rem;
  line-height: 1.65;
}

.career__metrics {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(120px, 1fr));
  gap: 1px;
  border: 1px solid var(--border);
  margin-bottom: 1.5rem;
  background: var(--border);
}

.career__metric {
  display: flex;
  flex-direction: column;
  gap: 0.25rem;
  padding: 1rem 1.1rem;
  background: var(--bg);
}

.career__metric strong {
  font-size: 1.35rem;
  font-weight: 400;
  letter-spacing: -0.02em;
  color: var(--text);
  line-height: 1.1;
}

.career__metric span {
  font-size: 0.68rem;
  letter-spacing: 0.08em;
  text-transform: uppercase;
  color: var(--text-muted);
  line-height: 1.35;
}

.career__focus {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 1px;
  background: var(--border);
  border: 1px solid var(--border);
}

.career__focus--3 {
  grid-template-columns: repeat(3, 1fr);
}

.career__focus-item {
  background: var(--bg-alt);
  padding: 1.1rem 1.15rem;
  transition: background var(--ease);
}

.career__focus-item:hover {
  background: var(--bg);
}

.career__focus-item h4 {
  font-size: 0.72rem;
  font-weight: 400;
  letter-spacing: 0.1em;
  text-transform: uppercase;
  color: var(--text);
  margin-bottom: 0.45rem;
}

.career__focus-item p {
  font-size: 0.85rem;
  color: var(--text-dim);
  line-height: 1.5;
  margin: 0;
}

/* ---------- Projects ---------- */
.projects__grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(280px, 1fr));
  gap: 1.25rem;
  align-items: start;
}
.project-card {
  display: block;
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--radius-md);
  overflow: hidden;
  transition: border-color var(--ease), transform var(--ease), box-shadow var(--ease);
}
.project-card:hover {
  border-color: var(--text);
  transform: translateY(-3px);
  box-shadow: 0 14px 28px -18px rgba(0, 0, 0, 0.35);
}
.project-card:focus-visible {
  outline: 2px solid var(--text);
  outline-offset: 2px;
}
.project-card__img {
  display: flex;
  flex-direction: column;
  background: #ffffff;
  border-bottom: 1px solid var(--border);
  overflow: hidden;
}
.project-card__img img {
  width: 100%;
  height: 200px;
  object-fit: contain;
  object-position: center;
  display: block;
  padding: 0.9rem 1rem;
  box-sizing: border-box;
  background: #ffffff;
  flex-shrink: 0;
  transition: transform 0.35s ease;
}
.project-card:hover .project-card__img img {
  transform: scale(1.02);
}
/* Label bar under the picture — does not cover/crop the image */
.project-card__overlay {
  position: relative;
  display: flex;
  flex-direction: column;
  padding: 0.7rem 1rem 0.85rem;
  background: #ffffff;
  border-top: 1px solid var(--border);
  flex-shrink: 0;
}
.project-card__overlay-tag {
  font-size: 0.62rem;
  font-weight: 400;
  letter-spacing: 0.1em;
  text-transform: uppercase;
  color: var(--text-muted);
  margin-bottom: 0.2rem;
}
.project-card__overlay-title {
  font-family: var(--font);
  font-size: 0.92rem;
  font-weight: 600;
  letter-spacing: 0.02em;
  line-height: 1.25;
  color: var(--text);
}
.project-card__body { padding: 1.25rem 1.3rem 1.4rem; }
.project-card__tag {
  display: block;
  font-size: 0.68rem;
  font-weight: 400;
  letter-spacing: 0.1em;
  text-transform: uppercase;
  color: var(--text-muted);
  background: none;
  padding: 0;
  margin-bottom: 0.55rem;
}
.project-card__body h3 {
  font-size: 1rem;
  font-weight: 600;
  letter-spacing: 0.01em;
  margin-bottom: 0.5rem;
  line-height: 1.35;
}
.project-card__body p {
  color: var(--text-dim);
  font-size: 0.88rem;
  margin-bottom: 0.85rem;
  line-height: 1.55;
}
.project-card__meta {
  font-size: 0.72rem;
  letter-spacing: 0.06em;
  text-transform: uppercase;
  color: var(--text-muted);
}
.project-card__cta {
  display: flex;
  align-items: center;
  gap: 0.4rem;
  margin-top: 0.9rem;
  font-size: 0.72rem;
  font-weight: 600;
  letter-spacing: 0.08em;
  text-transform: uppercase;
  color: var(--text);
}
.project-card__chevron {
  display: inline-block;
  width: 7px;
  height: 7px;
  border-right: 1.5px solid var(--text);
  border-bottom: 1.5px solid var(--text);
  transform: rotate(-45deg);
  transition: transform var(--ease);
}
.project-card:hover .project-card__chevron {
  transform: rotate(-45deg) translate(2px, 2px);
}

/* ---------- Project case-study page ---------- */
.project-back {
  display: inline-flex;
  align-items: center;
  gap: 0.5rem;
  font-size: 0.75rem;
  font-weight: 600;
  letter-spacing: 0.08em;
  text-transform: uppercase;
  color: var(--text-muted);
  border-bottom: none;
  margin-bottom: 1.6rem;
}
.project-back:hover { color: var(--text); border-bottom: none; }
.project-back::before {
  content: "";
  width: 8px;
  height: 8px;
  border-left: 1.5px solid currentColor;
  border-bottom: 1.5px solid currentColor;
  transform: rotate(45deg);
}

.project-hero {
  padding: 56px 0 40px;
}
.project-hero__tag {
  display: inline-block;
  font-size: 0.7rem;
  font-weight: 600;
  letter-spacing: 0.1em;
  text-transform: uppercase;
  color: var(--text);
  background: var(--surface);
  border: 1px solid var(--border);
  padding: 0.32rem 0.75rem;
  border-radius: 999px;
  margin-bottom: 1.1rem;
}
.project-hero__title {
  font-size: clamp(1.6rem, 3.2vw, 2.4rem);
  font-weight: 500;
  letter-spacing: 0.01em;
  line-height: 1.25;
  margin-bottom: 0.7rem;
  max-width: 820px;
}
.project-hero__meta {
  font-size: 0.78rem;
  letter-spacing: 0.08em;
  text-transform: uppercase;
  color: var(--text-muted);
}
.project-hero__media {
  min-height: 200px;
  max-height: min(42vh, 380px);
  overflow: hidden;
  background: #ffffff;
  border-top: 1px solid var(--border);
  border-bottom: 1px solid var(--border);
  display: flex;
  align-items: center;
  justify-content: center;
  padding: 1.25rem 1.5rem;
}
.project-hero__media img {
  width: auto;
  max-width: min(920px, 100%);
  max-height: min(36vh, 320px);
  height: auto;
  object-fit: contain;
  filter: grayscale(100%);
  background: #ffffff;
}

.project-page { padding-top: 3.5rem; }
.project-page__grid {
  display: grid;
  grid-template-columns: 1fr 300px;
  gap: 3rem;
  align-items: start;
}
.project-page__block { margin-bottom: 2.6rem; }
.project-page__block:last-child { margin-bottom: 0; }
.project-page__block h2 {
  display: flex;
  align-items: center;
  gap: 0.65rem;
  font-size: 0.78rem;
  font-weight: 600;
  letter-spacing: 0.12em;
  text-transform: uppercase;
  color: var(--text-muted);
  margin-bottom: 1.2rem;
}
.project-page__block h2::before {
  content: "";
  width: 18px;
  height: 1px;
  background: var(--border-strong);
  flex-shrink: 0;
}
.project-page__block ul {
  color: var(--text-dim);
  font-size: 0.96rem;
}
.project-page__block > ul > li {
  margin-bottom: 0.65rem;
  padding-left: 1.1rem;
  position: relative;
  line-height: 1.65;
}
.project-page__block > ul > li::before {
  content: "—";
  position: absolute;
  left: 0;
  color: var(--text-muted);
  font-size: 0.85rem;
}
.project-page__missions {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(230px, 1fr));
  gap: 1.15rem;
}
.project-page__mission-card {
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--radius-md);
  padding: 1.3rem 1.4rem;
  transition: border-color var(--ease);
}
.project-page__mission-card:hover { border-color: var(--border-strong); }
.project-page__mission-card h3 {
  font-size: 0.92rem;
  font-weight: 600;
  margin-bottom: 0.8rem;
}
.project-page__mission-card ul { font-size: 0.88rem; }
.project-page__mission-card li {
  margin-bottom: 0.5rem;
  padding-left: 1rem;
  position: relative;
  line-height: 1.6;
}
.project-page__mission-card li::before {
  content: "—";
  position: absolute;
  left: 0;
  color: var(--text-muted);
  font-size: 0.8rem;
}

.project-page__aside { display: flex; flex-direction: column; gap: 1.25rem; }
.project-page__card {
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--radius-md);
  padding: 1.4rem 1.5rem;
}
.project-page__card h3 {
  font-size: 0.72rem;
  font-weight: 600;
  letter-spacing: 0.1em;
  text-transform: uppercase;
  color: var(--text-muted);
  margin-bottom: 1rem;
}
.project-page__card .btn { width: 100%; text-align: center; }
.project-page__tags {
  display: flex;
  flex-wrap: wrap;
  gap: 0.5rem;
}
.project-page__tags span {
  font-size: 0.78rem;
  color: var(--text);
  background: var(--bg-alt);
  border: 1px solid var(--border);
  padding: 0.36rem 0.8rem;
  border-radius: 999px;
  letter-spacing: 0.02em;
}

.project-page__toc {
  display: flex;
  flex-direction: column;
  gap: 0.6rem;
}
.project-page__toc a {
  font-size: 0.82rem;
  color: var(--text-dim);
  border-bottom: none;
  line-height: 1.4;
}
.project-page__toc a:hover { color: var(--text); border-bottom: none; }

.project-page__pagination {
  display: flex;
  justify-content: space-between;
  gap: 1rem;
  margin-top: 3.5rem;
  padding-top: 2rem;
  border-top: 1px solid var(--border);
}
.project-page__pagination a {
  font-size: 0.78rem;
  font-weight: 600;
  letter-spacing: 0.06em;
  text-transform: uppercase;
  color: var(--text-dim);
  max-width: 46%;
  border-bottom: none;
}
.project-page__pagination a:hover { color: var(--text); border-bottom: none; }
.project-page__pagination .next { text-align: right; margin-left: auto; }

/* ---------- Academic case-study ("paper") mode ----------
   Used by in-depth project write-ups: numbered sections/subsections,
   an abstract box, numbered equations (rendered with MathJax),
   a nomenclature table and a references list. */
.paper__kicker {
  font-size: 0.7rem;
  font-weight: 600;
  letter-spacing: 0.12em;
  text-transform: uppercase;
  color: var(--text-muted);
  margin-bottom: 1.4rem;
}
.paper__abstract {
  background: var(--surface);
  border: 1px solid var(--border);
  border-left: 3px solid var(--text);
  border-radius: var(--radius-md);
  padding: 1.4rem 1.6rem;
  margin-bottom: 2.6rem;
}
.paper__abstract h2 {
  font-size: 0.7rem;
  font-weight: 600;
  letter-spacing: 0.12em;
  text-transform: uppercase;
  color: var(--text-muted);
  margin-bottom: 0.75rem;
}
.paper__abstract h2::before { content: none; }
.paper__abstract p {
  font-style: italic;
  color: var(--text-dim);
  font-size: 0.94rem;
  line-height: 1.7;
  margin: 0;
}

.paper { counter-reset: paper-eq; }
.paper__section { margin-bottom: 2.8rem; }
.paper__section:last-child { margin-bottom: 0; }
.paper__section h2 {
  counter-increment: paper-h2;
  counter-reset: paper-h3;
  display: flex;
  align-items: baseline;
  gap: 0.65rem;
  font-size: 1.05rem;
  font-weight: 600;
  letter-spacing: 0.01em;
  color: var(--text);
  text-transform: none;
  margin-bottom: 1.2rem;
  padding-bottom: 0.6rem;
  border-bottom: 1px solid var(--border);
}
.paper__section h2::before {
  content: counter(paper-h2) ".";
  color: var(--text-muted);
  font-weight: 600;
}
.paper__section h3 {
  counter-increment: paper-h3;
  display: flex;
  align-items: baseline;
  gap: 0.6rem;
  font-size: 0.92rem;
  font-weight: 600;
  margin: 1.6rem 0 0.9rem;
}
.paper__section h3::before {
  content: counter(paper-h2) "." counter(paper-h3);
  color: var(--text-muted);
  font-weight: 600;
}
.paper__section p {
  color: var(--text-dim);
  font-size: 0.94rem;
  line-height: 1.75;
  margin-bottom: 1.1rem;
}
.paper__section p:last-child { margin-bottom: 0; }
.paper__section ul,
.paper__section ol {
  color: var(--text-dim);
  font-size: 0.92rem;
  margin: 0 0 1.1rem;
}
.paper__section li {
  margin-bottom: 0.55rem;
  padding-left: 1.1rem;
  position: relative;
  line-height: 1.65;
}
.paper__section ul > li::before {
  content: "—";
  position: absolute;
  left: 0;
  color: var(--text-muted);
  font-size: 0.85rem;
}
.paper__section ol {
  counter-reset: olist;
  list-style: none;
}
.paper__section ol > li {
  counter-increment: olist;
  padding-left: 1.6rem;
}
.paper__section ol > li::before {
  content: counter(olist) ".";
  position: absolute;
  left: 0;
  color: var(--text-muted);
  font-weight: 600;
}
.paper__section strong { color: var(--text); font-weight: 600; }
.paper__section em { color: var(--text); }

.eq {
  counter-increment: paper-eq;
  position: relative;
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--radius-md);
  padding: 1rem 3.2rem 1rem 1.4rem;
  margin: 1.4rem 0;
  overflow-x: auto;
  font-size: 0.98rem;
}
.eq::after {
  content: "(" counter(paper-eq) ")";
  position: absolute;
  right: 1rem;
  top: 50%;
  transform: translateY(-50%);
  color: var(--text-muted);
  font-size: 0.78rem;
}
.eq mjx-container { margin: 0 !important; }

.paper__note {
  background: var(--bg-alt);
  border: 1px solid var(--border);
  border-radius: var(--radius-md);
  padding: 1rem 1.3rem;
  margin: 1.2rem 0;
  font-size: 0.88rem;
  color: var(--text-dim);
}
.paper__note strong {
  display: block;
  font-size: 0.68rem;
  font-weight: 700;
  letter-spacing: 0.1em;
  text-transform: uppercase;
  color: var(--text-muted);
  margin-bottom: 0.4rem;
}

.paper__figure {
  margin: 1.5rem 0;
  border: 1px solid var(--border);
  border-radius: var(--radius-md);
  overflow: hidden;
  /* Pure white photo well — never inherit grey --surface */
  background: #ffffff;
}
/* Default: pad + contain so diagrams/photos are not cropped or over-zoomed */
.paper__figure > img {
  width: auto;
  max-width: 100%;
  max-height: min(70vh, 580px);
  height: auto;
  display: block;
  margin: 0 auto;
  padding: 1rem 1.1rem;
  background: #ffffff;
  object-fit: contain;
  box-sizing: border-box;
}
.paper__figure-frame {
  display: flex;
  align-items: center;
  justify-content: center;
  padding: 1rem 1.1rem;
  background: #ffffff;
}
.paper__figure-frame img {
  width: auto;
  max-width: 100%;
  max-height: min(72vh, 640px);
  height: auto;
  margin: 0 auto;
  background: #ffffff;
}
.paper__figure figcaption {
  padding: 0.75rem 1.1rem;
  font-size: 0.8rem;
  color: var(--text-dim);
  line-height: 1.55;
  border-top: 1px solid var(--border);
  background: #ffffff;
}
.paper__figure figcaption strong { color: var(--text); }

/* Stack multi-panel FEA / lab result figures full-width for readability */
.paper__results {
  display: flex;
  flex-direction: column;
  gap: 1.25rem;
  margin: 1.5rem 0 0.5rem;
}
.paper__results > .paper__figure { margin: 0; }

.paper__figure--wide .paper__figure-frame {
  padding: 1.15rem 1.25rem;
}
.paper__figure--wide .paper__figure-frame img {
  max-height: min(80vh, 720px);
  width: 100%;
  max-width: 100%;
  object-fit: contain;
}
.paper__figure--fit .paper__figure-frame img {
  max-height: min(56vh, 420px);
}

.paper__figure-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(260px, 1fr));
  gap: 1.1rem;
  margin: 1.5rem 0;
}
.paper__figure-grid .paper__figure { margin: 0; }
.paper__figure-grid--pair {
  grid-template-columns: repeat(2, 1fr);
  margin: 0;
}
.paper__figure-grid--pair .paper__figure-frame img {
  max-height: min(48vh, 360px);
}

.paper__figure--narrow {
  max-width: 320px;
  margin-left: auto;
  margin-right: auto;
}
.paper__figure--narrow > img {
  width: 100%;
  max-width: 100%;
  max-height: none;
  height: auto;
  padding: 0.75rem;
  background: #ffffff;
}
.paper__figure--narrow .paper__figure-frame img {
  width: 100%;
  max-height: none;
  height: auto;
}

.paper__table-wrap { overflow-x: auto; margin-bottom: 1.2rem; }
.paper__table {
  width: 100%;
  border-collapse: collapse;
  font-size: 0.88rem;
}
.paper__table caption {
  text-align: left;
  font-size: 0.7rem;
  font-weight: 600;
  letter-spacing: 0.08em;
  text-transform: uppercase;
  color: var(--text-muted);
  margin-bottom: 0.6rem;
}
.paper__table th,
.paper__table td {
  border: 1px solid var(--border);
  padding: 0.55rem 0.75rem;
  text-align: left;
  color: var(--text-dim);
  vertical-align: top;
}
.paper__table th {
  background: var(--bg-alt);
  color: var(--text);
  font-weight: 600;
  white-space: nowrap;
}
.paper__table td:first-child { color: var(--text); font-weight: 600; white-space: nowrap; }

.paper__refs {
  list-style: none;
  counter-reset: refs;
  font-size: 0.86rem;
  color: var(--text-dim);
}
.paper__refs li {
  counter-increment: refs;
  position: relative;
  padding-left: 2rem;
  margin-bottom: 0.7rem;
  line-height: 1.6;
}
.paper__refs li::before {
  content: "[" counter(refs) "]";
  position: absolute;
  left: 0;
  color: var(--text-muted);
  font-weight: 600;
}

/* ---------- Research ---------- */
.research__grid {
  display: grid;
  grid-template-columns: 1fr 1.45fr;
  gap: 3.5rem;
  align-items: start;
  margin-top: 2.5rem;
}
.research__img img {
  border-radius: var(--radius-md);
  border: 1px solid var(--border);
}
.research__gallery {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 0.9rem;
}
.research__gallery figure {
  margin: 0;
  border: 1px solid var(--border);
  border-radius: var(--radius-md);
  overflow: hidden;
  background: var(--surface);
  display: flex;
  flex-direction: column;
}
.research__gallery img {
  width: 100%;
  height: 170px;
  object-fit: contain;
  object-position: center;
  display: block;
  background: #ffffff;
  padding: 0.55rem;
}
.research__gallery figcaption {
  padding: 0.55rem 0.75rem;
  font-size: 0.7rem;
  font-weight: 600;
  letter-spacing: 0.06em;
  text-transform: uppercase;
  color: var(--text-muted);
  border-top: 1px solid var(--border);
}
.research__badge {
  display: block;
  font-size: 0.7rem;
  font-weight: 400;
  letter-spacing: 0.1em;
  text-transform: uppercase;
  color: var(--text-muted);
  background: none;
  padding: 0;
  margin-bottom: 0.85rem;
}
.research__text h3 {
  font-size: 1.35rem;
  font-weight: 400;
  letter-spacing: 0.01em;
  margin-bottom: 1.1rem;
  line-height: 1.35;
}
.research__text p {
  color: var(--text-dim);
  margin-bottom: 1.5rem;
  font-size: 0.95rem;
}
.research__text p strong { color: var(--text); font-weight: 600; }
.research__text h4 {
  font-size: 0.72rem;
  font-weight: 400;
  letter-spacing: 0.12em;
  text-transform: uppercase;
  color: var(--text-muted);
  margin-bottom: 0.85rem;
}
.research__interests {
  margin-bottom: 1.75rem;
}
.research__interests li {
  color: var(--text-dim);
  padding: 0.4rem 0 0.4rem 1.1rem;
  position: relative;
  font-size: 0.92rem;
  border-bottom: 1px solid var(--border);
}
.research__interests li:last-child { border-bottom: none; }
.research__interests li::before {
  content: "";
  position: absolute;
  left: 0;
  top: 50%;
  width: 5px;
  height: 1px;
  background: var(--text-muted);
}
.research__actions {
  display: flex;
  flex-wrap: wrap;
  gap: 0.75rem;
}

/* ---------- Skills ---------- */
.skills__grid {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: 1px;
  background: var(--border);
  border: 1px solid var(--border);
  margin-top: 2.5rem;
}
.skills__col {
  background: var(--bg-alt);
  padding: 1.6rem 1.5rem;
  transition: background var(--ease);
}
.skills__col:hover {
  background: var(--bg);
}
.skills__col-head {
  display: flex;
  align-items: baseline;
  gap: 0.7rem;
  margin-bottom: 1.1rem;
  padding-bottom: 0.85rem;
  border-bottom: 1px solid var(--border);
}
.skills__index {
  font-size: 0.7rem;
  letter-spacing: 0.1em;
  color: var(--text-dim);
  font-variant-numeric: tabular-nums;
}
.skills__col h3 {
  font-size: 0.72rem;
  font-weight: 400;
  letter-spacing: 0.12em;
  text-transform: uppercase;
  margin: 0;
  color: var(--text);
}
.skills__tags {
  display: flex;
  flex-wrap: wrap;
  gap: 0.4rem;
}
.skills__tags span {
  font-size: 0.8rem;
  color: var(--text);
  background: transparent;
  border: 1px solid var(--border);
  padding: 0.3rem 0.7rem;
  border-radius: var(--radius);
  letter-spacing: 0.02em;
  transition: border-color var(--ease), background var(--ease);
}
.skills__tags span:hover {
  border-color: var(--text);
  background: var(--accent-soft);
  color: var(--text);
}

/* ---------- Education path ---------- */
.edu-path {
  margin-top: 2rem;
  display: flex;
  flex-direction: column;
  gap: 0;
}

.edu-step {
  display: grid;
  grid-template-columns: 88px 1fr;
  gap: 0 1.75rem;
  align-items: stretch;
}

.edu-step__marker {
  display: flex;
  flex-direction: column;
  align-items: center;
  position: relative;
}

.edu-step__year {
  font-size: 1.15rem;
  font-weight: 400;
  letter-spacing: 0.04em;
  color: var(--text);
  line-height: 1;
  margin-bottom: 0.65rem;
}

.edu-step__dot {
  width: 9px;
  height: 9px;
  border-radius: 50%;
  border: 1px solid var(--text);
  background: var(--bg);
  z-index: 1;
  flex-shrink: 0;
}

.edu-step:first-child .edu-step__dot {
  background: var(--text);
}

.edu-step__line {
  flex: 1;
  width: 1px;
  background: var(--border-strong);
  min-height: 2rem;
  margin-top: 0.5rem;
}

.edu-step__card {
  border: 1px solid var(--border);
  background: var(--bg);
  padding: 1.5rem 1.6rem 1.4rem;
  margin-bottom: 1.5rem;
  transition: border-color var(--ease);
}

.edu-step__card:hover {
  border-color: var(--text);
}

.edu-step:last-child .edu-step__card {
  margin-bottom: 0;
}

.edu-step__card--compact {
  padding: 1.25rem 1.6rem;
}

.edu-step__level {
  display: block;
  font-size: 0.68rem;
  letter-spacing: 0.14em;
  text-transform: uppercase;
  color: var(--text-muted);
  margin-bottom: 0.45rem;
}

.edu-step__card h3 {
  font-size: 1.2rem;
  font-weight: 400;
  letter-spacing: 0.01em;
  margin-bottom: 0.5rem;
  line-height: 1.3;
}

.edu-step__org-row {
  display: flex;
  align-items: center;
  gap: 0.65rem;
  margin-bottom: 0.2rem;
}

.edu-step__logo {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  width: 36px;
  height: 36px;
  padding: 0.3rem;
  border: 1px solid var(--border);
  background: #fff;
  flex-shrink: 0;
}
.edu-step__logo img {
  max-width: 100%;
  max-height: 100%;
  object-fit: contain;
}

.edu-step__org {
  font-size: 0.92rem;
  color: var(--text);
  font-weight: 600;
  margin-bottom: 0.2rem;
}
.edu-step__org-row .edu-step__org { margin-bottom: 0; }

.edu-step__place {
  font-size: 0.8rem;
  color: var(--text-muted);
  letter-spacing: 0.03em;
  margin-bottom: 0.85rem;
}

.edu-step__detail {
  font-size: 0.9rem;
  color: var(--text-dim);
  line-height: 1.6;
  max-width: 58ch;
  margin-bottom: 1rem;
}

.edu-step__tags {
  display: flex;
  flex-wrap: wrap;
  gap: 0.4rem;
}

.edu-step__tags span {
  font-size: 0.72rem;
  letter-spacing: 0.06em;
  text-transform: uppercase;
  color: var(--text-dim);
  border: 1px solid var(--border);
  padding: 0.25rem 0.6rem;
}

/* Certifications as stamps */
.cert-block {
  margin-top: 3.5rem;
}

.cert-block__title {
  font-size: 0.72rem;
  font-weight: 400;
  letter-spacing: 0.14em;
  text-transform: uppercase;
  color: var(--text-muted);
  margin-bottom: 1.25rem;
}

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

.cert-stamp {
  position: relative;
  border: 1px solid var(--border);
  background: var(--bg);
  padding: 1.4rem 1.15rem 1.25rem;
  min-height: 140px;
  display: flex;
  flex-direction: column;
  transition: border-color var(--ease), transform var(--ease);
}

.cert-stamp:hover {
  border-color: var(--text);
  transform: translateY(-2px);
}

.cert-stamp__year {
  position: absolute;
  top: 0.9rem;
  right: 1rem;
  font-size: 0.72rem;
  letter-spacing: 0.1em;
  color: var(--text-muted);
}

.cert-stamp h4 {
  font-size: 0.95rem;
  font-weight: 600;
  letter-spacing: 0.01em;
  line-height: 1.35;
  margin-bottom: 0.55rem;
  padding-right: 2.5rem;
  margin-top: 0.15rem;
}

.cert-stamp p {
  font-size: 0.8rem;
  color: var(--text-dim);
  line-height: 1.45;
  margin-top: auto;
}

/* Soft skills strip */
.soft-skills {
  margin-top: 2.75rem;
  padding-top: 2rem;
  border-top: 1px solid var(--border);
}

.soft-skills__title {
  font-size: 0.72rem;
  font-weight: 400;
  letter-spacing: 0.14em;
  text-transform: uppercase;
  color: var(--text-muted);
  margin-bottom: 1rem;
}

.soft-skills__list {
  display: flex;
  flex-wrap: wrap;
  gap: 0.5rem 0.65rem;
}

.soft-skills__list span {
  font-size: 0.82rem;
  letter-spacing: 0.03em;
  color: var(--text);
  border-bottom: 1px solid var(--border-strong);
  padding: 0.2rem 0;
  transition: border-color var(--ease);
}

.soft-skills__list span:hover {
  border-bottom-color: var(--text);
}

/* ---------- Contact ---------- */
.contact__inner { text-align: center; }
.contact__inner .section__title { display: inline-block; }
.contact__inner .section__title::after { margin-left: auto; margin-right: auto; }
.contact__inner .section__lead {
  margin-left: auto;
  margin-right: auto;
}
.contact__cards {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
  gap: 1rem;
  margin: 2.5rem 0;
}
.contact__card {
  display: flex;
  flex-direction: column;
  gap: 0.35rem;
  background: transparent;
  border: 1px solid var(--border);
  border-radius: var(--radius-md);
  padding: 1.35rem 1rem;
  color: var(--text);
  transition: border-color var(--ease);
  border-bottom: 1px solid var(--border);
}
.contact__card:hover {
  text-decoration: none;
  border-color: var(--text);
  transform: none;
}
.contact__label {
  font-size: 0.68rem;
  text-transform: uppercase;
  letter-spacing: 0.12em;
  color: var(--text-muted);
}
.contact__card strong {
  font-size: 0.9rem;
  font-weight: 400;
  word-break: break-word;
}
.contact__docs {
  display: flex;
  flex-wrap: wrap;
  gap: 0.75rem;
  justify-content: center;
}

/* ---------- Footer ---------- */
.footer {
  border-top: 1px solid var(--border);
  padding: 1.75rem 0;
  text-align: center;
  color: var(--text-muted);
  font-size: 0.78rem;
  letter-spacing: 0.04em;
}

/* ---------- Reveal animation ---------- */
.reveal {
  opacity: 0;
  transform: translateY(16px);
  transition: opacity 0.55s ease, transform 0.55s ease;
}
.reveal.visible {
  opacity: 1;
  transform: translateY(0);
}

/* ---------- Responsive ---------- */
@media (max-width: 900px) {
  .hero__inner {
    grid-template-columns: 1fr;
    text-align: center;
    gap: 2.5rem;
  }
  .hero__subtitle { margin-left: auto; margin-right: auto; }
  .hero__actions { justify-content: center; }
  .hero__stats {
    grid-template-columns: repeat(2, 1fr);
    gap: 1.25rem;
    text-align: left;
  }
  .hero__stats span { max-width: none; }
  .about__grid,
  .research__grid { grid-template-columns: 1fr; }
  .career__focus,
  .career__focus--3 { grid-template-columns: repeat(2, 1fr); }
  .cert-wall { grid-template-columns: repeat(2, 1fr); }
  .career__brand { text-align: left; }
  .section { padding: 80px 0; }
  .project-page__grid { grid-template-columns: 1fr; }
  .project-page__aside { flex-direction: row; flex-wrap: wrap; }
  .project-page__aside .project-page__card { flex: 1 1 260px; }
}

@media (max-width: 900px) {
  /* Sidebar collapses to a top bar + slide-in drawer on tablet/mobile. */
  body { padding-left: 0; padding-top: var(--nav-h); }
  .nav {
    inset: 0 0 auto 0;
    width: 100%;
    height: var(--nav-h);
    border-right: none;
    border-bottom: 1px solid var(--border);
  }
  .nav__inner {
    flex-direction: row;
    align-items: center;
    justify-content: space-between;
    height: var(--nav-h);
    padding: 0 1.25rem;
    gap: 0;
  }
  .nav__toggle { display: flex; }
  .nav__links {
    position: fixed;
    top: var(--nav-h);
    right: 0;
    flex-direction: column;
    align-items: flex-start;
    gap: 0;
    flex: none;
    width: min(280px, 82vw);
    height: calc(100vh - var(--nav-h));
    background: var(--bg);
    border-left: 1px solid var(--border);
    padding: 1.25rem 0;
    transform: translateX(100%);
    transition: transform 0.3s ease;
    overflow-y: auto;
  }
  .nav__links.open { transform: translateX(0); }
  .nav__links a {
    padding: 0.9rem 1.6rem;
    width: 100%;
    border-bottom: none;
    border-left: none;
  }
  .nav__links a:hover,
  .nav__links a.active {
    background: var(--bg-alt);
    border-bottom: none;
    border-left: none;
  }
  .nav__cta {
    margin: 0.5rem 1.6rem !important;
    width: calc(100% - 3.2rem);
    text-align: center;
    border-left: 1px solid var(--text) !important;
  }
  .nav__lang {
    margin: 0.75rem 1.6rem 0;
    padding-left: 0;
  }
  .hero { padding: 40px 0 56px; }
}

@media (max-width: 720px) {
  .hero__stats { grid-template-columns: 1fr 1fr; }
  .section { padding: 64px 0; }
  .projects__grid { grid-template-columns: 1fr; }
  .skills__grid { grid-template-columns: 1fr; }

  .career__role {
    grid-template-columns: 40px 1fr;
    gap: 0 1rem;
  }
  .career__index { font-size: 0.68rem; }
  .career__monogram {
    min-width: 42px;
    height: 42px;
    font-size: 0.65rem;
  }
  .career__metrics {
    grid-template-columns: repeat(2, 1fr);
  }
  .career__focus,
  .career__focus--3 { grid-template-columns: 1fr; }

  .edu-step {
    grid-template-columns: 56px 1fr;
    gap: 0 1rem;
  }
  .edu-step__year { font-size: 0.95rem; }
  .edu-step__card { padding: 1.2rem 1.15rem; }

  .cert-wall { grid-template-columns: 1fr 1fr; gap: 0.75rem; }
  .cert-stamp { min-height: 120px; padding: 1.15rem 1rem; }
}

@media (max-width: 420px) {
  .cert-wall { grid-template-columns: 1fr; }
  .career__header { flex-direction: column; }
}

/* ---------- Project case-study page on small screens ---------- */
@media (max-width: 700px) {
  .project-hero { padding: calc(var(--nav-h) + 32px) 0 28px; }
  .project-hero__media {
    max-height: none;
    min-height: 0;
    padding: 1rem;
  }
  .project-hero__media img {
    max-height: 240px;
  }
  .paper__figure-grid--pair {
    grid-template-columns: 1fr;
  }
  .paper__figure > img,
  .paper__figure-frame img,
  .paper__figure--wide .paper__figure-frame img,
  .paper__figure--fit .paper__figure-frame img {
    max-height: none;
  }
  .research__gallery img {
    height: 150px;
  }
  .project-page__missions { grid-template-columns: 1fr; }
  .project-page__pagination {
    flex-direction: column;
    align-items: flex-start;
  }
  .project-page__pagination a { max-width: 100%; }
  .project-page__pagination .next { text-align: left; margin-left: 0; }
}