/* ============================================================
   Yasser Elhouderi — portfolio stylesheet
   Design tokens first; sections in page order; responsive
   and print rules at the end.
   ============================================================ */

/* ---------- Tokens ---------- */
:root {
  --bg: #060b16;
  --bg-2: #0a1322;
  --surface: #0d1728;
  --surface-2: #111e33;
  --line: rgba(148, 180, 220, 0.10);
  --line-strong: rgba(148, 180, 220, 0.22);
  --ink: #e6edf7;
  --ink-soft: #b9c7da;
  --muted: #8fa3bf;
  --faint: #5e7491;
  --accent: #38bdf8;
  --accent-2: #2dd4bf;
  --accent-ink: #062033;
  --glow: rgba(56, 189, 248, 0.14);
  --danger: #f87171;
  --ok: #34d399;
  --font-display: "Space Grotesk", "Segoe UI", system-ui, sans-serif;
  --font-body: "Inter", "Segoe UI", system-ui, sans-serif;
  --font-mono: "JetBrains Mono", "Consolas", monospace;
  --radius: 14px;
  --radius-sm: 9px;
  --nav-h: 68px;
  --container: 1160px;
  --ease: cubic-bezier(0.22, 1, 0.36, 1);
}

/* ---------- Reset-ish base ---------- */
*, *::before, *::after { box-sizing: border-box; }
html {
  scroll-behavior: smooth;
  scroll-padding-top: calc(var(--nav-h) + 12px);
  overflow-x: hidden;
}
body {
  margin: 0;
  background: var(--bg);
  color: var(--ink);
  font-family: var(--font-body);
  font-size: 16.5px;
  line-height: 1.65;
  -webkit-font-smoothing: antialiased;
  overflow-x: hidden;
}
img { max-width: 100%; height: auto; display: block; }
h1, h2, h3, h4 { font-family: var(--font-display); line-height: 1.12; margin: 0 0 0.5em; }
p { margin: 0 0 1em; }
ul, ol { margin: 0; padding: 0; }
a { color: var(--accent); text-decoration: none; }
a:hover { text-decoration: none; }
.mono { font-family: var(--font-mono); font-size: 0.78rem; letter-spacing: 0.08em; text-transform: uppercase; }
.icon { width: 1.1em; height: 1.1em; flex: none; }

:focus-visible {
  outline: 2px solid var(--accent);
  outline-offset: 3px;
  border-radius: 4px;
}

.skip-link {
  position: fixed; top: -100px; left: 16px; z-index: 200;
  background: var(--accent); color: var(--accent-ink);
  padding: 10px 16px; border-radius: 8px; font-weight: 600;
  transition: top 0.2s var(--ease);
}
.skip-link:focus { top: 12px; }

.container {
  width: min(var(--container), 100% - 48px);
  margin-inline: auto;
}

/* ---------- Fixed backdrop ---------- */
.backdrop { position: fixed; inset: 0; z-index: -1; overflow: hidden; }
.backdrop-grid {
  position: absolute; inset: 0;
  background-image:
    linear-gradient(rgba(148, 180, 220, 0.045) 1px, transparent 1px),
    linear-gradient(90deg, rgba(148, 180, 220, 0.045) 1px, transparent 1px);
  background-size: 72px 72px;
  mask-image: radial-gradient(ellipse 90% 70% at 50% 30%, black 30%, transparent 100%);
}
.backdrop-glow { position: absolute; border-radius: 50%; filter: blur(90px); }
.backdrop-glow--1 {
  width: 620px; height: 620px; top: -220px; right: -160px;
  background: radial-gradient(circle, rgba(56, 189, 248, 0.10), transparent 65%);
}
.backdrop-glow--2 {
  width: 520px; height: 520px; bottom: -200px; left: -140px;
  background: radial-gradient(circle, rgba(45, 212, 191, 0.07), transparent 65%);
}

/* ---------- Header / nav ---------- */
.site-header {
  position: fixed; top: 0; left: 0; right: 0; z-index: 100;
  background: rgba(6, 11, 22, 0.72);
  backdrop-filter: blur(14px);
  -webkit-backdrop-filter: blur(14px);
  border-bottom: 1px solid transparent;
  transition: border-color 0.3s, background 0.3s;
}
.site-header.is-scrolled {
  background: rgba(6, 11, 22, 0.88);
  border-bottom-color: var(--line);
}
.nav {
  width: min(var(--container), 100% - 48px);
  margin-inline: auto;
  height: var(--nav-h);
  display: flex; align-items: center; justify-content: space-between; gap: 16px;
}
.nav-brand {
  display: flex; align-items: center; gap: 10px;
  color: var(--ink); font-family: var(--font-display); font-weight: 600; font-size: 1.02rem;
}
.brand-mark { width: 30px; height: 30px; color: var(--accent); }
.brand-dot { fill: var(--accent-2); }
.brand-accent { color: var(--accent); }
.brand-mark--footer { width: 22px; height: 22px; }

.nav-menu {
  display: flex; align-items: center; gap: 4px; list-style: none;
}
.nav-link {
  display: inline-block; padding: 8px 13px; border-radius: 8px;
  color: var(--muted); font-size: 0.92rem; font-weight: 500;
  transition: color 0.2s, background 0.2s;
}
.nav-link:hover { color: var(--ink); background: rgba(148, 180, 220, 0.07); }
.nav-link[aria-current="true"] { color: var(--accent); }
.nav-cta-wrap { margin-left: 8px; }

.nav-toggle {
  display: none;
  background: none; border: 1px solid var(--line-strong); border-radius: 8px;
  width: 42px; height: 38px; padding: 0; cursor: pointer;
  flex-direction: column; align-items: center; justify-content: center; gap: 4px;
}
.nav-toggle-bar {
  width: 17px; height: 2px; background: var(--ink); border-radius: 2px;
  transition: transform 0.25s var(--ease), opacity 0.2s;
}
.nav-toggle[aria-expanded="true"] .nav-toggle-bar:nth-child(1) { transform: translateY(6px) rotate(45deg); }
.nav-toggle[aria-expanded="true"] .nav-toggle-bar:nth-child(2) { opacity: 0; }
.nav-toggle[aria-expanded="true"] .nav-toggle-bar:nth-child(3) { transform: translateY(-6px) rotate(-45deg); }

.scroll-progress {
  position: absolute; bottom: -1px; left: 0; height: 2px; width: 0%;
  background: linear-gradient(90deg, var(--accent), var(--accent-2));
}

/* ---------- Buttons ---------- */
.btn {
  display: inline-flex; align-items: center; justify-content: center; gap: 9px;
  padding: 13px 24px; border-radius: 999px;
  font-family: var(--font-display); font-weight: 600; font-size: 0.95rem;
  border: 1px solid transparent; cursor: pointer;
  transition: transform 0.2s var(--ease), box-shadow 0.25s, background 0.2s, border-color 0.2s, color 0.2s;
}
.btn:active { transform: translateY(1px); }
.btn-solid {
  background: linear-gradient(135deg, var(--accent), var(--accent-2));
  color: var(--accent-ink);
}
.btn-solid:hover { box-shadow: 0 6px 28px var(--glow); transform: translateY(-2px); }
.btn-ghost {
  background: transparent; color: var(--ink);
  border-color: var(--line-strong);
}
.btn-ghost:hover { border-color: var(--accent); color: var(--accent); transform: translateY(-2px); }
.btn-small { padding: 8px 16px; font-size: 0.85rem; }

/* ---------- Hero ---------- */
.hero {
  position: relative;
  min-height: 100svh;
  display: flex; align-items: center;
  padding: calc(var(--nav-h) + 40px) 0 60px;
  overflow: hidden;
}
.hero-canvas {
  position: absolute; inset: 0; width: 100%; height: 100%;
  opacity: 0.8;
}
.hero-inner {
  position: relative; z-index: 1;
  display: grid; grid-template-columns: 1.15fr 0.85fr;
  gap: clamp(32px, 6vw, 80px); align-items: center;
}
.kicker {
  font-family: var(--font-mono); font-size: 0.8rem; letter-spacing: 0.22em;
  text-transform: uppercase; color: var(--accent-2); margin-bottom: 18px;
}
.hero-title {
  font-size: clamp(2.9rem, 7.5vw, 5.4rem);
  font-weight: 700; letter-spacing: -0.02em; margin-bottom: 20px;
}
.grad-text {
  background: linear-gradient(120deg, var(--accent) 10%, var(--accent-2) 90%);
  -webkit-background-clip: text; background-clip: text; color: transparent;
}
.hero-sub {
  max-width: 54ch; color: var(--ink-soft);
  font-size: clamp(1.02rem, 1.4vw, 1.14rem); margin-bottom: 30px;
}
.hero-actions { display: flex; flex-wrap: wrap; gap: 14px; margin-bottom: 28px; }
.hero-links {
  list-style: none; display: flex; flex-wrap: wrap; gap: 8px 22px; margin-bottom: 34px;
}
.hero-link {
  display: inline-flex; align-items: center; gap: 8px;
  color: var(--muted); font-size: 0.92rem;
  transition: color 0.2s;
}
a.hero-link:hover { color: var(--accent); }
.hero-link .icon { color: var(--accent); opacity: 0.85; }
.hero-facts {
  display: flex; flex-wrap: wrap; gap: 12px 36px; margin: 0;
  border-top: 1px solid var(--line); padding-top: 22px;
}
.fact dt {
  font-family: var(--font-mono); font-size: 0.68rem; letter-spacing: 0.14em;
  text-transform: uppercase; color: var(--faint); margin-bottom: 3px;
}
.fact dd { margin: 0; font-family: var(--font-display); font-weight: 600; font-size: 1.0rem; }

.hero-portrait { display: flex; justify-content: center; }
.portrait-frame {
  position: relative; margin: 0;
  width: clamp(240px, 30vw, 380px);
}
.portrait-frame img {
  width: 100%; aspect-ratio: 1; object-fit: cover;
  border-radius: 22px;
  border: 1px solid var(--line-strong);
  position: relative; z-index: 1;
}
.portrait-ring {
  position: absolute; inset: -14px; z-index: 0;
  border-radius: 30px;
  background:
    linear-gradient(140deg, rgba(56,189,248,0.35), transparent 30%, transparent 70%, rgba(45,212,191,0.35)) border-box;
  border: 1px solid transparent;
  mask: linear-gradient(#fff 0 0) padding-box, linear-gradient(#fff 0 0);
  mask-composite: exclude;
  -webkit-mask: linear-gradient(#fff 0 0) padding-box, linear-gradient(#fff 0 0);
  -webkit-mask-composite: xor;
}
.portrait-frame::after {
  content: ""; position: absolute; inset: -40px; z-index: -1;
  background: radial-gradient(circle, var(--glow), transparent 70%);
}
.portrait-tag {
  position: absolute; z-index: 2; bottom: -12px; right: -6px;
  background: var(--surface-2); border: 1px solid var(--line-strong);
  color: var(--accent-2);
  padding: 7px 14px; border-radius: 999px;
}
.hero-scroll-hint {
  position: absolute; left: 50%; bottom: 22px; transform: translateX(-50%);
  color: var(--faint); z-index: 1;
  padding: 8px; border-radius: 50%;
  animation: bob 2.6s ease-in-out infinite;
  transition: color 0.2s;
}
.hero-scroll-hint:hover { color: var(--accent); }
@keyframes bob {
  0%, 100% { transform: translateX(-50%) translateY(0); }
  50% { transform: translateX(-50%) translateY(7px); }
}

/* ---------- Sections (shared) ---------- */
.section { padding: clamp(72px, 10vw, 130px) 0; position: relative; }
.section--tint {
  background: linear-gradient(180deg, transparent, rgba(56, 189, 248, 0.035) 30%, rgba(45, 212, 191, 0.03) 70%, transparent);
}
.section-head { max-width: 640px; margin-bottom: clamp(36px, 5vw, 60px); }
.section-index {
  color: var(--accent); margin-bottom: 8px;
}
.section-index::after {
  content: ""; display: inline-block; vertical-align: middle;
  width: 54px; height: 1px; background: linear-gradient(90deg, var(--accent), transparent);
  margin-left: 12px;
}
.section-title {
  font-size: clamp(1.9rem, 4vw, 2.7rem); letter-spacing: -0.015em; margin-bottom: 12px;
}
.section-lede { color: var(--muted); font-size: 1.05rem; margin: 0; }

/* ---------- About ---------- */
.about-grid {
  display: grid; grid-template-columns: 1.6fr 1fr; gap: clamp(28px, 4vw, 56px);
  align-items: start;
}
.about-story p { color: var(--ink-soft); font-size: 1.04rem; }
.about-story p:last-child { margin-bottom: 0; }
.about-facts {
  background: var(--surface);
  border: 1px solid var(--line); border-radius: var(--radius);
  padding: 26px 26px 10px;
  position: sticky; top: calc(var(--nav-h) + 24px);
}
.about-facts-title { color: var(--accent-2); margin: 0 0 18px; }
.about-facts ul { list-style: none; }
.about-facts li {
  display: flex; flex-direction: column; gap: 2px;
  padding: 13px 0; border-top: 1px solid var(--line);
}
.about-facts li:first-child { border-top: 0; }
.about-facts span {
  font-family: var(--font-mono); font-size: 0.68rem; letter-spacing: 0.14em;
  text-transform: uppercase; color: var(--faint);
}
.about-facts strong { font-weight: 600; font-size: 0.98rem; }

/* ---------- Expertise ---------- */
.expertise-filter {
  display: flex; flex-wrap: wrap; gap: 10px; margin-bottom: 34px;
}
.chip {
  border: 1px solid var(--line-strong); background: transparent;
  color: var(--muted); border-radius: 999px; cursor: pointer;
  padding: 8px 16px; font-family: var(--font-display); font-weight: 500; font-size: 0.88rem;
  transition: color 0.2s, border-color 0.2s, background 0.2s, transform 0.2s var(--ease);
}
.chip:hover { color: var(--ink); border-color: var(--accent); transform: translateY(-1px); }
.chip[aria-pressed="true"] {
  background: linear-gradient(135deg, rgba(56,189,248,0.16), rgba(45,212,191,0.16));
  border-color: var(--accent); color: var(--ink);
}
.expertise-grid {
  display: grid; grid-template-columns: repeat(3, 1fr); gap: 20px;
}
.skill-card {
  background: var(--surface); border: 1px solid var(--line);
  border-radius: var(--radius); padding: 24px;
  transition: border-color 0.25s, transform 0.3s var(--ease), box-shadow 0.3s, opacity 0.3s;
}
.skill-card:hover { border-color: var(--line-strong); transform: translateY(-4px); box-shadow: 0 14px 40px rgba(2, 8, 20, 0.5); }
.skill-card.is-dimmed { opacity: 0.28; }
.skill-card-head { display: flex; align-items: center; gap: 12px; margin-bottom: 8px; }
.skill-icon {
  width: 38px; height: 38px; flex: none; border-radius: 10px;
  display: grid; place-items: center;
  background: linear-gradient(135deg, rgba(56,189,248,0.14), rgba(45,212,191,0.14));
  color: var(--accent);
}
.skill-icon svg { width: 20px; height: 20px; }
.skill-card h3 { font-size: 1.08rem; margin: 0; }
.skill-blurb { color: var(--muted); font-size: 0.9rem; margin-bottom: 16px; }
.skill-list { list-style: none; display: flex; flex-wrap: wrap; gap: 8px; }
.skill-pill {
  position: relative;
  border: 1px solid var(--line); border-radius: 999px;
  background: rgba(148, 180, 220, 0.05);
  padding: 5px 12px; font-size: 0.82rem; color: var(--ink-soft);
  cursor: default;
  transition: border-color 0.2s, color 0.2s, background 0.2s;
}
.skill-pill:hover, .skill-pill:focus-visible {
  border-color: var(--accent); color: var(--ink);
  background: rgba(56, 189, 248, 0.08);
}
.skill-tip {
  position: absolute; left: 50%; bottom: calc(100% + 9px); transform: translateX(-50%) translateY(4px);
  width: max-content; max-width: min(230px, calc(100vw - 32px));
  background: var(--surface-2); border: 1px solid var(--line-strong);
  color: var(--ink-soft); font-size: 0.78rem; line-height: 1.45;
  padding: 8px 12px; border-radius: 8px;
  opacity: 0; pointer-events: none;
  transition: opacity 0.18s, transform 0.18s var(--ease);
  z-index: 5;
  box-shadow: 0 10px 30px rgba(2, 8, 20, 0.6);
}
.skill-pill:hover .skill-tip, .skill-pill:focus-visible .skill-tip {
  opacity: 1; transform: translateX(-50%) translateY(0);
}

/* ---------- Experience timeline ---------- */
.timeline { list-style: none; position: relative; max-width: 780px; }
.timeline::before {
  content: ""; position: absolute; left: 8px; top: 6px; bottom: 6px; width: 1px;
  background: linear-gradient(180deg, var(--accent), var(--line-strong) 30%, var(--line-strong) 90%, transparent);
}
.tl-item { position: relative; padding: 0 0 34px 44px; }
.tl-item:last-child { padding-bottom: 0; }
.tl-node {
  position: absolute; left: 0; top: 6px;
  width: 17px; height: 17px; border-radius: 50%;
  background: var(--bg);
  border: 2px solid var(--accent);
  box-shadow: 0 0 0 4px rgba(56, 189, 248, 0.12);
}
.tl-item:first-child .tl-node { background: var(--accent); box-shadow: 0 0 18px rgba(56, 189, 248, 0.55); }
.tl-card {
  background: var(--surface); border: 1px solid var(--line);
  border-radius: var(--radius); padding: 26px 28px;
  transition: border-color 0.25s, transform 0.3s var(--ease), box-shadow 0.3s;
}
.tl-card:hover { border-color: var(--line-strong); transform: translateX(4px); box-shadow: 0 14px 40px rgba(2, 8, 20, 0.45); }
.tl-role { font-size: 1.22rem; margin-bottom: 2px; }
.tl-org { color: var(--accent); font-weight: 600; font-family: var(--font-display); margin-bottom: 6px; }
.tl-org-note { color: var(--faint); font-weight: 400; font-size: 0.85em; }
.tl-meta { display: flex; flex-wrap: wrap; gap: 10px; color: var(--faint); margin-bottom: 14px; letter-spacing: 0.06em; }
.tl-desc { color: var(--ink-soft); }
.tl-points { list-style: none; margin-bottom: 16px; }
.tl-points li {
  position: relative; padding-left: 22px; margin-bottom: 8px;
  color: var(--muted); font-size: 0.95rem;
}
.tl-points li::before {
  content: ""; position: absolute; left: 2px; top: 0.62em;
  width: 8px; height: 2px; border-radius: 2px;
  background: var(--accent-2);
}
.tl-tags { list-style: none; display: flex; flex-wrap: wrap; gap: 8px; }
.tl-tags li {
  font-family: var(--font-mono); font-size: 0.72rem; letter-spacing: 0.05em;
  color: var(--accent-2);
  border: 1px solid rgba(45, 212, 191, 0.25); border-radius: 6px;
  padding: 3px 9px;
  background: rgba(45, 212, 191, 0.05);
}

/* ---------- Projects ---------- */
.projects-grid {
  display: grid; grid-template-columns: repeat(3, 1fr); gap: 20px;
}
.project-card {
  position: relative; text-align: left; width: 100%;
  background: var(--surface); border: 1px solid var(--line);
  border-radius: var(--radius); padding: 26px;
  color: var(--ink); font: inherit; cursor: pointer;
  display: flex; flex-direction: column; gap: 0;
  transition: border-color 0.25s, transform 0.3s var(--ease), box-shadow 0.3s;
}
.project-card:hover {
  border-color: var(--accent); transform: translateY(-5px);
  box-shadow: 0 18px 48px rgba(2, 8, 20, 0.55);
}
.project-card-body { display: flex; flex-direction: column; flex: 1; }
.project-card--featured {
  grid-column: span 3;
  display: grid; grid-template-columns: 1.2fr 1fr; gap: 30px; align-items: center;
  background:
    linear-gradient(120deg, rgba(56, 189, 248, 0.07), transparent 45%),
    var(--surface);
}
.project-tag {
  font-family: var(--font-mono); font-size: 0.7rem; letter-spacing: 0.16em;
  text-transform: uppercase; color: var(--accent-2); margin-bottom: 12px;
}
.project-card h3 { font-size: 1.18rem; margin-bottom: 10px; }
.project-card--featured h3 { font-size: clamp(1.35rem, 2.4vw, 1.7rem); }
.project-short { color: var(--muted); font-size: 0.95rem; flex: 1; }
.project-open {
  margin-top: 18px;
  display: inline-flex; align-items: center; gap: 7px;
  color: var(--accent); font-family: var(--font-display); font-weight: 600; font-size: 0.9rem;
}
.project-open .icon { transition: transform 0.25s var(--ease); }
.project-card:hover .project-open .icon { transform: translate(2px, -2px); }
.project-outcome-hint {
  margin-top: 14px; padding-top: 14px; border-top: 1px solid var(--line);
  color: var(--ink-soft); font-size: 0.9rem;
}
.project-outcome-hint strong { color: var(--accent-2); font-family: var(--font-mono); font-weight: 500; font-size: 0.82rem; }

/* Pipeline diagram (featured research card + modal) */
.pipeline { display: flex; flex-direction: column; gap: 0; margin: 6px 0 0; }
.pipe-step {
  display: flex; align-items: center; gap: 12px;
  background: rgba(148, 180, 220, 0.05);
  border: 1px solid var(--line); border-radius: 10px;
  padding: 10px 14px; font-size: 0.87rem; color: var(--ink-soft);
}
.pipe-step .pipe-num {
  font-family: var(--font-mono); font-size: 0.7rem; color: var(--accent);
  border: 1px solid rgba(56, 189, 248, 0.35); border-radius: 6px;
  width: 24px; height: 24px; display: grid; place-items: center; flex: none;
}
.pipe-arrow {
  align-self: center; color: var(--faint); line-height: 1; padding: 3px 0;
}
.pipe-arrow svg { width: 15px; height: 15px; display: block; }

/* ---------- Project modal ---------- */
.modal { position: fixed; inset: 0; z-index: 150; display: grid; place-items: center; padding: 24px; }
.modal[hidden] { display: none; }
.modal-backdrop {
  position: absolute; inset: 0;
  background: rgba(3, 6, 13, 0.78);
  backdrop-filter: blur(6px);
  -webkit-backdrop-filter: blur(6px);
}
.modal-panel {
  position: relative; z-index: 1;
  width: min(680px, 100%);
  max-height: min(84vh, 800px); overflow-y: auto;
  scrollbar-width: thin; scrollbar-color: rgba(148, 180, 220, 0.25) transparent;
  background: var(--bg-2); border: 1px solid var(--line-strong);
  border-radius: 18px; padding: clamp(24px, 4vw, 40px);
  box-shadow: 0 30px 90px rgba(0, 0, 0, 0.6);
  animation: modal-in 0.3s var(--ease);
}
@keyframes modal-in {
  from { opacity: 0; transform: translateY(18px) scale(0.98); }
  to { opacity: 1; transform: none; }
}
.modal-close {
  position: absolute; top: 14px; right: 14px;
  background: var(--surface-2); border: 1px solid var(--line-strong);
  color: var(--muted); border-radius: 10px;
  width: 38px; height: 38px; display: grid; place-items: center; cursor: pointer;
  transition: color 0.2s, border-color 0.2s;
}
.modal-close:hover { color: var(--ink); border-color: var(--accent); }
.modal-content h3 { font-size: 1.5rem; margin: 6px 0 14px; padding-right: 40px; }
.modal-meta {
  font-family: var(--font-mono); font-size: 0.76rem; letter-spacing: 0.06em;
  color: var(--faint); margin: -8px 0 18px;
}
.modal-list { list-style: none; }
.modal-list li {
  position: relative; padding-left: 22px; margin-bottom: 7px;
  color: var(--ink-soft); font-size: 0.94rem;
}
.modal-list li::before {
  content: ""; position: absolute; left: 2px; top: 0.62em;
  width: 8px; height: 2px; border-radius: 2px;
  background: var(--accent-2);
}
.modal-section { margin-bottom: 18px; }
.modal-section h4 {
  font-family: var(--font-mono); font-weight: 500; font-size: 0.72rem;
  letter-spacing: 0.16em; text-transform: uppercase; color: var(--accent-2);
  margin-bottom: 6px;
}
.modal-section p { color: var(--ink-soft); font-size: 0.97rem; margin: 0; }
.modal-tech { list-style: none; display: flex; flex-wrap: wrap; gap: 8px; }
.modal-tech li {
  font-family: var(--font-mono); font-size: 0.74rem;
  color: var(--accent-2); border: 1px solid rgba(45, 212, 191, 0.25);
  border-radius: 6px; padding: 3px 10px; background: rgba(45, 212, 191, 0.05);
}
.modal-links { display: flex; flex-wrap: wrap; gap: 10px; }

/* ---------- Education ---------- */
.edu-path { list-style: none; position: relative; max-width: 820px; margin-bottom: clamp(40px, 6vw, 64px); }
.edu-path::before {
  content: ""; position: absolute; left: 37px; top: 10px; bottom: 10px; width: 1px;
  background: linear-gradient(180deg, var(--line-strong), var(--accent));
}
.edu-step { position: relative; display: flex; gap: 26px; padding-bottom: 26px; }
.edu-step:last-child { padding-bottom: 0; }
.edu-year {
  flex: none; width: 74px; text-align: center;
  color: var(--accent); background: var(--bg);
  border: 1px solid var(--line-strong); border-radius: 999px;
  padding: 6px 0; height: fit-content; position: relative; z-index: 1;
  letter-spacing: 0.1em;
}
.edu-step:last-child .edu-year {
  background: linear-gradient(135deg, var(--accent), var(--accent-2));
  color: var(--accent-ink); border-color: transparent; font-weight: 500;
}
.edu-card {
  flex: 1;
  background: var(--surface); border: 1px solid var(--line);
  border-radius: var(--radius); padding: 22px 26px;
  transition: border-color 0.25s, transform 0.3s var(--ease);
}
.edu-card:hover { border-color: var(--line-strong); transform: translateX(4px); }
.edu-card--phd { border-color: rgba(56, 189, 248, 0.3); }
.edu-card h3 { font-size: 1.12rem; margin-bottom: 4px; }
.edu-school { color: var(--accent); font-family: var(--font-display); font-weight: 600; font-size: 0.92rem; margin-bottom: 8px; }
.edu-focus { color: var(--muted); font-size: 0.93rem; margin: 0; }

.pubs {
  max-width: 820px;
  background: var(--surface); border: 1px solid var(--line);
  border-radius: var(--radius); padding: 28px 30px;
}
.pubs-title { font-size: 1.1rem; margin-bottom: 16px; }
.pubs-list { list-style: none; counter-reset: pub; }
.pubs-list li {
  counter-increment: pub;
  display: flex; gap: 16px; align-items: baseline;
  padding: 12px 0; border-top: 1px solid var(--line);
}
.pubs-list li::before {
  content: counter(pub, decimal-leading-zero);
  font-family: var(--font-mono); font-size: 0.78rem; color: var(--accent);
  flex: none;
}
.pub-title { color: var(--ink-soft); font-size: 0.96rem; }
.pub-venue { color: var(--faint); font-size: 0.84rem; font-style: italic; }
.pub-year { margin-left: auto; font-family: var(--font-mono); font-size: 0.78rem; color: var(--accent-2); flex: none; }

/* ---------- Current focus ---------- */
.focus-grid { display: grid; grid-template-columns: repeat(3, 1fr); gap: 20px; }
.focus-card {
  background: var(--surface); border: 1px solid var(--line);
  border-radius: var(--radius); padding: 26px;
  border-top: 2px solid var(--accent);
  transition: transform 0.3s var(--ease), border-color 0.25s;
}
.focus-card:nth-child(2) { border-top-color: var(--accent-2); }
.focus-card:nth-child(3) { border-top-color: var(--accent); }
.focus-card:hover { transform: translateY(-4px); }
.focus-card h3 { font-size: 1.08rem; }
.focus-card p { color: var(--muted); font-size: 0.94rem; margin: 0; }

/* ---------- Contact ---------- */
.contact-grid {
  display: grid; grid-template-columns: 1fr 1.2fr; gap: clamp(32px, 5vw, 64px);
  align-items: start;
}
.contact-blurb { color: var(--ink-soft); font-size: 1.03rem; }
.contact-email {
  display: inline-flex; align-items: center; gap: 10px;
  font-family: var(--font-display); font-weight: 600; font-size: 1.05rem;
  color: var(--accent); margin: 6px 0 18px;
  border-bottom: 1px dashed rgba(56, 189, 248, 0.4); padding-bottom: 3px;
  transition: color 0.2s, border-color 0.2s;
  overflow-wrap: anywhere;
}
.contact-email:hover { color: var(--accent-2); border-color: var(--accent-2); }
.contact-note { color: var(--faint); }

.contact-form {
  background: var(--surface); border: 1px solid var(--line);
  border-radius: var(--radius); padding: clamp(22px, 3vw, 34px);
}
.form-row { margin-bottom: 18px; }
.form-row label {
  display: block; font-family: var(--font-display); font-weight: 600;
  font-size: 0.88rem; margin-bottom: 7px;
}
.form-row input, .form-row textarea {
  width: 100%; background: var(--bg);
  border: 1px solid var(--line-strong); border-radius: var(--radius-sm);
  color: var(--ink); font: inherit; font-size: 0.96rem;
  padding: 11px 14px;
  transition: border-color 0.2s, box-shadow 0.2s;
}
.form-row textarea { resize: vertical; min-height: 110px; }
.form-row input:focus, .form-row textarea:focus {
  outline: none; border-color: var(--accent);
  box-shadow: 0 0 0 3px rgba(56, 189, 248, 0.15);
}
.form-row input[aria-invalid="true"], .form-row textarea[aria-invalid="true"] {
  border-color: var(--danger);
}
.form-err { color: var(--danger); font-size: 0.82rem; margin: 6px 0 0; }
.btn-submit { width: 100%; position: relative; }
.btn-submit[disabled] { opacity: 0.6; cursor: not-allowed; transform: none; box-shadow: none; }
.btn-spinner {
  display: none; width: 16px; height: 16px; border-radius: 50%;
  border: 2px solid rgba(6, 32, 51, 0.3); border-top-color: var(--accent-ink);
  animation: spin 0.7s linear infinite;
}
.btn-submit.is-loading .btn-spinner { display: inline-block; }
@keyframes spin { to { transform: rotate(360deg); } }
.form-status { min-height: 1.4em; font-size: 0.9rem; margin: 12px 0 0; }
.form-status.is-ok { color: var(--ok); }
.form-status.is-err { color: var(--danger); }
.form-hint { color: var(--faint); font-size: 0.8rem; margin: 8px 0 0; }

/* ---------- Footer ---------- */
.site-footer { border-top: 1px solid var(--line); padding: 30px 0; }
.footer-inner {
  display: flex; flex-wrap: wrap; gap: 14px 30px; align-items: center; justify-content: space-between;
}
.footer-name { display: flex; align-items: center; gap: 10px; margin: 0; font-family: var(--font-display); font-weight: 600; font-size: 0.95rem; }
.footer-name .brand-mark { color: var(--accent); }
.footer-tag { color: var(--faint); margin: 0; }
.footer-top {
  display: inline-flex; align-items: center; gap: 8px;
  color: var(--muted); font-size: 0.9rem; font-weight: 500;
  transition: color 0.2s;
}
.footer-top:hover { color: var(--accent); }

/* ---------- Scroll reveals ---------- */
.reveal {
  opacity: 0; transform: translateY(26px);
  transition: opacity 0.7s var(--ease), transform 0.7s var(--ease);
}
.reveal.is-visible { opacity: 1; transform: none; }
html.no-reveal .reveal { opacity: 1; transform: none; transition: none; }

/* ---------- Reduced motion ---------- */
@media (prefers-reduced-motion: reduce) {
  html { scroll-behavior: auto; }
  *, *::before, *::after {
    animation-duration: 0.01ms !important;
    animation-iteration-count: 1 !important;
    transition-duration: 0.01ms !important;
  }
  .reveal { opacity: 1; transform: none; }
  .hero-scroll-hint { animation: none; }
}

/* ---------- Responsive ---------- */
@media (max-width: 1024px) {
  .expertise-grid, .projects-grid { grid-template-columns: repeat(2, 1fr); }
  .project-card--featured { grid-column: span 2; }
  .focus-grid { grid-template-columns: 1fr 1fr; }
  .focus-card:last-child { grid-column: span 2; }
}

@media (max-width: 860px) {
  .hero { padding-top: calc(var(--nav-h) + 28px); }
  .hero-inner { grid-template-columns: 1fr; gap: 40px; }
  .hero-portrait { order: -1; justify-content: flex-start; }
  .portrait-frame { width: clamp(200px, 36vw, 260px); }
  .hero-title { font-size: clamp(2.6rem, 10vw, 3.6rem); }
  .about-grid, .contact-grid { grid-template-columns: 1fr; }
  .about-facts { position: static; padding-bottom: 12px; }
  .project-card--featured { grid-template-columns: 1fr; gap: 20px; }
}

@media (max-width: 880px) {
  /* Tooltips are hover/keyboard affordances — off on touch-size layouts,
     where they could also poke past the viewport edge. */
  .skill-tip { display: none; }
  .nav-toggle { display: flex; }
  .nav-menu {
    position: fixed; top: var(--nav-h); left: 0; right: 0;
    flex-direction: column; align-items: stretch; gap: 2px;
    background: rgba(6, 11, 22, 0.97);
    backdrop-filter: blur(16px);
    -webkit-backdrop-filter: blur(16px);
    border-bottom: 1px solid var(--line);
    padding: 14px 24px 22px;
    transform: translateY(-12px); opacity: 0; visibility: hidden; pointer-events: none;
    transition: transform 0.3s var(--ease), opacity 0.25s, visibility 0.3s;
    max-height: calc(100vh - var(--nav-h)); overflow-y: auto;
  }
  .nav-menu.is-open { transform: none; opacity: 1; visibility: visible; pointer-events: auto; }
  .nav-link { display: block; padding: 13px 10px; font-size: 1.02rem; border-radius: 10px; }
  .nav-cta-wrap { margin: 12px 0 0; }
  .nav-cta-wrap .btn { width: 100%; }
}

@media (max-width: 640px) {
  body { font-size: 16px; }
  .container { width: calc(100% - 40px); }
  .nav { width: calc(100% - 40px); }
  .expertise-grid, .projects-grid, .focus-grid { grid-template-columns: 1fr; }
  .project-card--featured, .focus-card:last-child { grid-column: auto; }
  .tl-item { padding-left: 34px; }
  .tl-card { padding: 22px 20px; }
  .edu-path::before { left: 30px; }
  .edu-step { flex-direction: column; gap: 10px; }
  .edu-year { width: 62px; font-size: 0.72rem; }
  .pubs { padding: 22px 20px; }
  .pubs-list li { flex-wrap: wrap; }
  .pub-year { margin-left: 32px; }
  .hero-facts { gap: 12px 24px; }
  .footer-inner { flex-direction: column; align-items: flex-start; }
}

@media (max-width: 400px) {
  .container { width: calc(100% - 32px); }
  .nav { width: calc(100% - 32px); }
  .hero-actions .btn { width: 100%; }
  .portrait-frame { width: min(220px, 70vw); }
}

/* ---------- Print (résumé-style) ---------- */
@media print {
  :root { --ink: #111; }
  body { background: #fff; color: #111; font-size: 11pt; }
  .backdrop, .site-header, .hero-canvas, .hero-scroll-hint, .hero-actions,
  .expertise-filter, .contact-form, .site-footer, .modal, .portrait-ring,
  .portrait-tag, .project-open, .form-hint { display: none !important; }
  .section, .hero { padding: 16pt 0; min-height: 0; }
  .container { width: 100%; }
  .hero-inner, .about-grid, .contact-grid { display: block; }
  .hero-portrait { display: none; }
  h1, h2, h3, h4, .tl-org, .edu-school, .section-index, .kicker { color: #000 !important; }
  .grad-text { background: none; color: #000; -webkit-text-fill-color: #000; }
  .hero-sub, .about-story p, .tl-desc, .tl-points li, .edu-focus, .pub-title,
  .section-lede, .skill-blurb, .contact-blurb, .focus-card p { color: #333 !important; }
  .tl-card, .edu-card, .pubs, .skill-card, .project-card, .focus-card, .about-facts {
    background: #fff; border: 1pt solid #ccc; box-shadow: none;
    break-inside: avoid;
  }
  .tl-tags li, .modal-tech li, .skill-pill { color: #333; border-color: #bbb; background: #fff; }
  a { color: #000; text-decoration: underline; }
  .reveal { opacity: 1 !important; transform: none !important; }
  .timeline::before, .edu-path::before { background: #ccc; }
}