/* ————————————————— Design System ————————————————— */
:root {
  --bg: #FBFAF8;
  --bg-alt: #F3F1EB;
  --card: #FFFFFF;
  --ink: #0F172A;
  --ink-soft: #334155;
  --muted: #6B7280;
  --line: #E7E2D6;
  --accent: #4F46E5;
  --accent-2: #7C3AED;
  --gold: #C9A86A;
  --accent-soft: #EEF2FF;
  --radius: 18px;
  --radius-sm: 12px;
  --shadow: 0 8px 30px rgba(15,23,42,0.08);
  --shadow-lg: 0 20px 60px rgba(79,70,229,0.15);
  --nav-h: 72px;
}

[data-theme="dark"] {
  --bg: #0B0F1E;
  --bg-alt: #111827;
  --card: #151D32;
  --ink: #E2E8F0;
  --ink-soft: #CBD5E1;
  --muted: #94A3B8;
  --line: #1E293B;
  --accent: #818CF8;
  --accent-2: #A78BFA;
  --accent-soft: #1E1B4B;
  --shadow: 0 8px 30px rgba(0,0,0,0.4);
  --shadow-lg: 0 20px 60px rgba(0,0,0,0.5);
}

* { box-sizing: border-box; }
html { scroll-behavior: smooth; scroll-padding-top: calc(var(--nav-h) + 12px); }
body {
  margin: 0;
  font-family: 'Inter', system-ui, -apple-system, sans-serif;
  background: var(--bg);
  color: var(--ink);
  line-height: 1.65;
  transition: background .35s ease, color .35s ease;
  overflow-x: hidden;
}

.container { max-width: 1160px; margin: 0 auto; padding: 0 24px; }

/* Progress */
.progress-bar {
  position: fixed; top: 0; left: 0; height: 3px; width: 0%;
  background: linear-gradient(90deg, var(--accent), var(--accent-2), var(--gold));
  z-index: 100; transition: width .1s linear;
}

/* Nav */
.nav {
  position: sticky; top: 0; z-index: 50;
  height: var(--nav-h);
  background: color-mix(in srgb, var(--bg) 82%, transparent);
  backdrop-filter: blur(14px) saturate(1.2);
  border-bottom: 1px solid var(--line);
  transition: background .3s ease;
}
.nav.scrolled { box-shadow: var(--shadow); }
.nav-inner { display: flex; align-items: center; justify-content: space-between; height: var(--nav-h); }
.brand { display: flex; align-items: center; gap: 12px; text-decoration: none; color: var(--ink); }
.brand-mark {
  width: 40px; height: 40px; border-radius: 12px;
  background: linear-gradient(135deg, var(--accent), var(--accent-2));
  color: white; display: grid; place-items: center;
  font-family: 'Fraunces', serif; font-weight: 700; font-size: 1.2rem;
  box-shadow: var(--shadow);
}
.brand-text { font-weight: 700; letter-spacing: -0.01em; font-size: 1.05rem; }
.nav-links { display: flex; gap: 6px; }
.nav-links a {
  text-decoration: none; color: var(--muted); font-weight: 500; font-size: 0.95rem;
  padding: 8px 14px; border-radius: 999px; transition: all .2s ease;
}
.nav-links a:hover { color: var(--ink); background: var(--bg-alt); }
.nav-links a.active { color: var(--accent); background: var(--accent-soft); font-weight: 600; }
.nav-actions { display: flex; align-items: center; gap: 10px; }
.theme-toggle {
  width: 42px; height: 42px; border-radius: 12px; border: 1px solid var(--line);
  background: var(--card); cursor: pointer; font-size: 1.15rem; color: var(--ink);
  display: grid; place-items: center; transition: transform .2s ease;
}
.theme-toggle:hover { transform: rotate(18deg); }
.lang-toggle {
  height: 42px; min-width: 52px; padding: 0 12px; border-radius: 12px; border: 1px solid var(--line);
  background: var(--card); cursor: pointer; font-size: .85rem; font-weight: 700; color: var(--ink);
  display: grid; place-items: center; transition: border-color .2s ease, color .2s ease;
}
.lang-toggle:hover { border-color: var(--accent); color: var(--accent); }
.nav-toggle {
  display: none; width: 42px; height: 42px; border-radius: 12px;
  border: 1px solid var(--line); background: var(--card); cursor: pointer; color: var(--ink);
}

/* Hero */
.hero { position: relative; overflow: hidden; padding: 0; min-height: 92vh; display: flex; align-items: center; }
.hero-bg { position: absolute; inset: 0; pointer-events: none; }
.orb { position: absolute; border-radius: 50%; filter: blur(80px); opacity: .5; animation: float 14s ease-in-out infinite; }
.orb-1 { width: 520px; height: 520px; background: radial-gradient(circle, #4F46E5 0%, transparent 70%); top: -120px; right: -80px; }
.orb-2 { width: 420px; height: 420px; background: radial-gradient(circle, #C9A86A 0%, transparent 70%); bottom: -100px; left: -80px; animation-delay: -5s; opacity: .35; }
.orb-3 { width: 300px; height: 300px; background: radial-gradient(circle, #7C3AED 0%, transparent 70%); top: 40%; left: 40%; animation-delay: -9s; opacity: .25; }
[data-theme="dark"] .orb { opacity: .28; }
.hero-grid-pattern {
  position: absolute; inset: 0;
  background-image: linear-gradient(var(--line) 1px, transparent 1px), linear-gradient(90deg, var(--line) 1px, transparent 1px);
  background-size: 56px 56px; opacity: .28;
  mask-image: radial-gradient(ellipse 80% 70% at 50% 30%, black 30%, transparent 75%);
}
@keyframes float {
  0%,100% { transform: translate(0,0) scale(1); }
  50% { transform: translate(-28px, 22px) scale(1.06); }
}

.hero-inner {
  position: relative; z-index: 1;
  display: grid; grid-template-columns: 1.35fr .85fr; gap: 48px; align-items: center;
  padding: 96px 24px 84px;
  width: 100%;
}
.eyebrow {
  display: inline-flex; align-items: center; gap: 10px;
  font-size: .82rem; font-weight: 600; letter-spacing: .08em; text-transform: uppercase;
  background: var(--card); border: 1px solid var(--line);
  padding: 8px 16px; border-radius: 999px; margin: 0 0 22px;
  box-shadow: var(--shadow);
}
.pulse-dot { width: 8px; height: 8px; border-radius: 50%; background: #10B981; animation: pulse 2s infinite; }
@keyframes pulse { 0%,100% { box-shadow: 0 0 0 0 rgba(16,185,129,.5);} 50% { box-shadow: 0 0 0 7px rgba(16,185,129,0);} }

.hero h1 {
  font-family: 'Fraunces', serif; font-weight: 700;
  font-size: clamp(3.2rem, 7vw, 5.2rem); line-height: .98; letter-spacing: -0.03em;
  margin: 0 0 14px;
  background: linear-gradient(135deg, var(--ink) 30%, var(--accent) 100%);
  -webkit-background-clip: text; -webkit-text-fill-color: transparent; background-clip: text;
}
.typing-line { font-size: 1.25rem; font-weight: 600; color: var(--accent); min-height: 2rem; margin: 0 0 18px; }
.typing-prefix { opacity: .5; margin-right: 8px; }
.caret { animation: blink 1s step-end infinite; font-weight: 300; }
@keyframes blink { 50% { opacity: 0; } }

.lede { font-size: 1.08rem; color: var(--ink-soft); max-width: 560px; margin: 0 0 32px; }
.hero-actions { display: flex; gap: 14px; flex-wrap: wrap; margin-bottom: 34px; }
.btn {
  display: inline-flex; align-items: center; gap: 10px;
  padding: 14px 26px; border-radius: 14px; text-decoration: none;
  font-weight: 600; font-size: .98rem; cursor: pointer; border: none;
  transition: transform .18s ease, box-shadow .18s ease;
}
.btn:hover { transform: translateY(-2px); }
.btn.primary {
  background: linear-gradient(135deg, var(--accent), var(--accent-2));
  color: white; box-shadow: var(--shadow-lg);
}
.btn.ghost {
  background: var(--card); color: var(--ink); border: 1.5px solid var(--line);
}
.hero-meta { display: flex; gap: 22px; flex-wrap: wrap; }
.meta-item { display: flex; align-items: center; gap: 8px; font-size: .9rem; color: var(--muted); font-weight: 500; }
.meta-icon { color: var(--gold); }

/* Profile card */
.hero-card { display: flex; justify-content: center; }
.profile-card {
  background: color-mix(in srgb, var(--card) 88%, transparent);
  backdrop-filter: blur(20px);
  border: 1px solid var(--line); border-radius: 22px; padding: 28px;
  width: 100%; max-width: 360px; box-shadow: var(--shadow-lg);
  transform: rotate(1.2deg); transition: transform .3s ease;
}
.profile-card:hover { transform: rotate(0deg) translateY(-4px); }
.profile-top { display: flex; gap: 16px; align-items: center; margin-bottom: 20px; }
.avatar {
  width: 64px; height: 64px; border-radius: 18px; flex-shrink: 0;
  background: linear-gradient(135deg, var(--accent), var(--gold));
  display: grid; place-items: center; color: white; font-weight: 800; font-size: 1.1rem;
  font-family: 'Fraunces', serif;
}
.profile-top h3 { margin: 0; font-size: 1.1rem; }
.profile-top p { margin: 2px 0 0; font-size: .88rem; color: var(--muted); }
.profile-stats { display: grid; grid-template-columns: repeat(3, 1fr); gap: 12px; margin-bottom: 18px; text-align: center; }
.profile-stats div { background: var(--bg-alt); border-radius: 12px; padding: 12px 6px; }
.profile-stats strong { display: block; font-size: 1.4rem; font-family: 'Fraunces', serif; color: var(--accent); }
.profile-stats span { font-size: .78rem; color: var(--muted); }
.profile-tags { display: flex; gap: 8px; flex-wrap: wrap; margin-bottom: 18px; }
.profile-tags span {
  font-size: .78rem; font-weight: 600; padding: 6px 12px; border-radius: 999px;
  background: var(--accent-soft); color: var(--accent);
}
.profile-link { color: var(--accent); font-weight: 600; text-decoration: none; font-size: .92rem; }

.scroll-hint {
  position: absolute; bottom: 28px; left: 50%; transform: translateX(-50%);
  width: 28px; height: 48px; border: 2px solid var(--muted); border-radius: 16px;
  display: flex; justify-content: center; padding-top: 8px; opacity: .6;
}
.scroll-hint span { width: 4px; height: 10px; background: var(--muted); border-radius: 4px; animation: scrollHint 1.8s infinite; }
@keyframes scrollHint { 0% { transform: translateY(0); opacity: 1;} 100% { transform: translateY(16px); opacity: 0;} }

/* Sections */
.section { padding: 96px 0; }
.section.alt { background: var(--bg-alt); position: relative; }
.section-eyebrow {
  font-size: .8rem; font-weight: 700; letter-spacing: .14em; text-transform: uppercase;
  color: var(--accent); margin: 0 0 12px;
}
.section-head { max-width: 720px; margin-bottom: 44px; }
.section-head h2 {
  font-family: 'Fraunces', serif; font-size: clamp(2rem, 4vw, 2.9rem);
  letter-spacing: -0.02em; line-height: 1.1; margin: 0 0 12px;
}
.section-sub { color: var(--muted); font-size: 1.05rem; margin: 0; }

.card {
  background: var(--card); border: 1px solid var(--line); border-radius: var(--radius);
  padding: 30px; box-shadow: var(--shadow);
  transition: transform .25s ease, box-shadow .25s ease, opacity .6s ease;
}
.card:hover { transform: translateY(-3px); box-shadow: var(--shadow-lg); }
.card h3 { margin: 0 0 10px; font-size: 1.15rem; letter-spacing: -0.01em; }
.card p { margin: 0 0 14px; color: var(--ink-soft); }
.card p:last-child { margin-bottom: 0; }
.card ul { margin: 10px 0 0; padding-left: 20px; color: var(--ink-soft); }
.card li { margin-bottom: 7px; }
.card-icon {
  width: 48px; height: 48px; border-radius: 14px; display: grid; place-items: center;
  background: linear-gradient(135deg, var(--accent-soft), transparent);
  font-size: 1.4rem; margin-bottom: 16px; border: 1px solid var(--line);
}
.muted { color: var(--muted); }
.text-link { color: var(--accent); font-weight: 600; text-decoration: none; }
code { background: var(--bg-alt); padding: 3px 8px; border-radius: 8px; font-size: .82em; border: 1px solid var(--line); }
.patent-code { display: inline-block; margin-top: 8px; line-height: 1.8; }

.about-grid { display: grid; grid-template-columns: 1.4fr .9fr; gap: 20px; margin-bottom: 28px; }
.feature-card.highlight {
  background: linear-gradient(135deg, var(--accent-soft), var(--card));
  border-color: var(--accent);
}
.stats-row { display: grid; grid-template-columns: repeat(4, 1fr); gap: 16px; }
.stat-card {
  background: var(--card); border: 1px solid var(--line); border-radius: var(--radius);
  padding: 26px 20px; text-align: center; transition: transform .25s ease;
}
.stat-card:hover { transform: translateY(-4px); }
.stat-card strong { display: block; font-family: 'Fraunces', serif; font-size: 2.4rem; color: var(--ink); }
.stat-card strong span { color: var(--accent); }
.stat-card > span { font-size: .88rem; color: var(--muted); }

/* Education */
.edu-grid { display: grid; grid-template-columns: repeat(2, 1fr); gap: 18px; margin-bottom: 36px; }
.edu-card { position: relative; overflow: hidden; }
.edu-card.featured { border-color: var(--gold); background: linear-gradient(135deg, var(--card), color-mix(in srgb, var(--gold) 8%, var(--card))); }
.edu-badge {
  display: inline-block; font-size: .75rem; font-weight: 800; letter-spacing: .1em;
  background: var(--ink); color: var(--bg); padding: 5px 12px; border-radius: 999px; margin-bottom: 14px;
}
.edu-card.featured .edu-badge { background: var(--gold); color: #1a1a1a; }
.two-col { display: grid; grid-template-columns: 1fr 1fr; gap: 28px; }
.mini-title { font-size: 1.05rem; margin: 0 0 16px; font-weight: 700; }
.chips { display: flex; flex-wrap: wrap; gap: 10px; }
.chip {
  background: var(--card); border: 1px solid var(--line); padding: 11px 16px;
  border-radius: 999px; font-size: .88rem; transition: transform .2s ease;
}
.chip:hover { transform: translateY(-2px); border-color: var(--accent); }
.chip strong { color: var(--accent); }

/* Expertise */
.expertise-grid { display: grid; grid-template-columns: repeat(3, 1fr); gap: 18px; }
.exp-card { position: relative; overflow: hidden; cursor: default; }
.exp-card::after {
  content: ''; position: absolute; top: 0; left: 0; right: 0; height: 3px;
  background: linear-gradient(90deg, var(--accent), var(--gold));
  transform: scaleX(0); transform-origin: left; transition: transform .35s ease;
}
.exp-card:hover::after, .exp-card:focus::after { transform: scaleX(1); }
.exp-icon {
  width: 44px; height: 44px; border-radius: 12px; display: grid; place-items: center;
  background: var(--accent-soft); color: var(--accent); font-size: 1.3rem; margin-bottom: 14px;
}
.exp-bar { height: 6px; background: var(--bg-alt); border-radius: 999px; margin-top: 16px; overflow: hidden; }
.exp-bar span {
  display: block; height: 100%; width: 0;
  background: linear-gradient(90deg, var(--accent), var(--accent-2));
  border-radius: 999px; transition: width 1.2s cubic-bezier(.22,1,.36,1);
}

/* Contact */
.contact-wrap { display: grid; grid-template-columns: 1.2fr .8fr; gap: 32px; align-items: start; }
.contact-wrap h2 { font-family: 'Fraunces', serif; font-size: 2.4rem; margin: 0 0 12px; letter-spacing: -0.02em; }
.contact-rows { display: flex; flex-direction: column; gap: 12px; margin-top: 28px; }
.contact-row {
  display: flex; align-items: center; gap: 16px; padding: 18px 20px;
  background: var(--card); border: 1px solid var(--line); border-radius: var(--radius-sm);
  text-decoration: none; color: var(--ink); transition: transform .2s ease, border-color .2s ease;
}
.contact-row:hover { transform: translateX(4px); border-color: var(--accent); }
.contact-row.static { cursor: default; }
.contact-row.static:hover { transform: none; border-color: var(--line); }
.c-icon {
  width: 44px; height: 44px; border-radius: 12px; flex-shrink: 0;
  background: var(--accent-soft); color: var(--accent);
  display: grid; place-items: center; font-size: 1.2rem; font-weight: 700;
}
.contact-row strong { font-size: .82rem; text-transform: uppercase; letter-spacing: .08em; color: var(--muted); }
.c-arrow { margin-left: auto; color: var(--accent); font-size: 1.2rem; }
.contact-card h3 { margin-top: 0; }
.copy-feedback { min-height: 1.4em; font-size: .9rem; color: #10B981; margin: 10px 0 0; }

/* Footer */
footer { border-top: 1px solid var(--line); padding: 36px 0; background: var(--bg-alt); }
.footer-inner { display: flex; justify-content: space-between; align-items: center; gap: 20px; flex-wrap: wrap; }
.footer-inner p { margin: 4px 0 0; }
.back-to-top {
  width: 48px; height: 48px; border-radius: 14px; border: 1px solid var(--line);
  background: var(--card); color: var(--ink); font-size: 1.3rem; cursor: pointer;
  transition: transform .2s ease; box-shadow: var(--shadow);
}
.back-to-top:hover { transform: translateY(-4px); }

/* Reveal */
.reveal { opacity: 0; transform: translateY(28px); transition: opacity .7s ease, transform .7s cubic-bezier(.22,1,.36,1); }
.reveal.visible { opacity: 1; transform: translateY(0); }

/* Responsive */
@media (max-width: 960px) {
  .hero-inner { grid-template-columns: 1fr; padding: 72px 24px 60px; gap: 36px; }
  .hero-card { order: -1; }
  .profile-card { transform: none; max-width: 100%; }
  .about-grid, .two-col, .contact-wrap { grid-template-columns: 1fr; }
  .expertise-grid { grid-template-columns: 1fr 1fr; }
  .stats-row { grid-template-columns: 1fr 1fr; }
  .edu-grid { grid-template-columns: 1fr; }
  /* Hamburger nav for tablet & phone (prevents crowding at 641–960px) */
  .nav-links {
    display: none; position: absolute; top: var(--nav-h); left: 0; right: 0;
    background: var(--card); flex-direction: column; padding: 12px;
    border-bottom: 1px solid var(--line); box-shadow: var(--shadow);
  }
  .nav-links.open { display: flex; }
  .nav-links a { padding: 12px 16px; }
  .nav-toggle { display: grid; place-items: center; }
  .brand-text { display: none; }
}
@media (max-width: 640px) {
  .expertise-grid { grid-template-columns: 1fr; }
  .section { padding: 64px 0; }
}

/* ————— Professional Experience Cards (v4) ————— */
.exp-list { display: flex; flex-direction: column; gap: 22px; max-width: 900px; }
.exp-list .exp-card {
  background: var(--card); border: 1px solid var(--line);
  border-radius: var(--radius); padding: 30px 32px;
  box-shadow: var(--shadow); position: relative; overflow: hidden;
  transition: transform .25s ease, box-shadow .25s ease;
}
.exp-list .exp-card::before {
  content: ''; position: absolute; left: 0; top: 0; bottom: 0; width: 4px;
  background: linear-gradient(to bottom, var(--accent), var(--accent-2));
  opacity: .85;
}
.exp-list .exp-card:hover { transform: translateY(-3px); box-shadow: var(--shadow-lg); }
.exp-list .exp-card.exp-featured { border-color: var(--gold); }
.exp-list .exp-card.exp-featured::before { background: linear-gradient(to bottom, var(--gold), var(--accent)); }
.exp-list .exp-top { display: flex; align-items: center; gap: 12px; flex-wrap: wrap; margin-bottom: 10px; }
.exp-list .exp-date {
  font-size: .78rem; font-weight: 800; letter-spacing: .1em; text-transform: uppercase;
  color: #fff; background: linear-gradient(135deg, var(--accent), var(--accent-2));
  padding: 5px 14px; border-radius: 999px;
}
.exp-list .exp-location { font-size: .88rem; color: var(--muted); font-weight: 500; }
.exp-list .exp-location::before { content: '◈ '; color: var(--gold); }
.exp-list .exp-title {
  font-family: 'Fraunces', serif; font-size: 1.45rem; font-weight: 700;
  letter-spacing: -0.01em; margin: 0 0 4px; line-height: 1.25;
}
.exp-list .exp-company { font-size: 1.02rem; font-weight: 600; color: var(--accent); margin: 0 0 14px; }
.exp-list .exp-context {
  background: var(--bg-alt); border: 1px solid var(--line);
  border-radius: var(--radius-sm); padding: 14px 18px; margin-bottom: 18px;
}
.exp-list .exp-context-label {
  display: inline-block; font-size: .7rem; font-weight: 800; letter-spacing: .12em;
  text-transform: uppercase; color: var(--muted); margin-bottom: 6px;
}
.exp-list .exp-context p { margin: 0; font-size: .92rem; color: var(--ink-soft); line-height: 1.6; }
.exp-list .exp-body { margin-bottom: 18px; }
.exp-list .exp-role-label {
  font-size: .72rem; font-weight: 800; letter-spacing: .12em; text-transform: uppercase;
  color: var(--accent); margin: 0 0 10px;
}
.exp-list .exp-body p { margin: 0 0 10px; color: var(--ink-soft); font-size: .98rem; }
.exp-list .exp-body p:last-child { margin-bottom: 0; }
.exp-list .exp-body ul { margin: 0; padding: 0; list-style: none; }
.exp-list .exp-body ul li {
  position: relative; padding-left: 26px; margin-bottom: 10px;
  color: var(--ink-soft); font-size: .96rem; line-height: 1.6;
}
.exp-list .exp-body ul li::before {
  content: '▸'; position: absolute; left: 2px; top: 0;
  color: var(--accent); font-weight: 800;
}
.exp-list .exp-body ul li:last-child { margin-bottom: 0; }
.exp-list .exp-tags { display: flex; flex-wrap: wrap; gap: 8px; border-top: 1px dashed var(--line); padding-top: 16px; }
.exp-list .exp-tags span {
  font-size: .78rem; font-weight: 600; padding: 6px 13px; border-radius: 999px;
  background: var(--accent-soft); color: var(--accent); border: 1px solid transparent;
}
@media (max-width: 640px) {
  .exp-list .exp-card { padding: 22px 20px; }
  .exp-list .exp-title { font-size: 1.25rem; }
}