/* ════════════════════════════════════════
   TRẦN VĂN CÔNG — DARK MODERN THEME
   ════════════════════════════════════════ */

:root {
  --bg:        #0D0F14;
  --bg-2:      #13161E;
  --bg-3:      #1A1E2A;
  --bg-card:   #1E2230;
  --border:    rgba(255,255,255,0.08);
  --white:     #FFFFFF;
  --gray-1:    #E8EAF0;
  --gray-2:    #9AA0B4;
  --gray-3:    #5A6070;
  --accent:    #4F8EF7;
  --accent-2:  #7C5CFC;
  --accent-grd: linear-gradient(135deg, #4F8EF7 0%, #7C5CFC 100%);
  --green:     #3DD68C;

  --font-display: 'Inter', 'DM Sans', sans-serif;
  --font-body:    'DM Sans', sans-serif;
  --font-mono:    'DM Mono', monospace;

  --nav-h: 72px;
  --ease: cubic-bezier(0.25, 0.1, 0.25, 1);
  --ease-out: cubic-bezier(0.16, 1, 0.3, 1);
  --radius: 16px;
}

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

html { scroll-behavior: smooth; font-size: 16px; }

body {
  background: var(--bg);
  color: var(--gray-1);
  font-family: var(--font-body);
  font-weight: 300;
  line-height: 1.6;
  overflow-x: hidden;
}

a { text-decoration: none; color: inherit; }

img { display: block; max-width: 100%; }

/* ─── Scrollbar ─── */
::-webkit-scrollbar { width: 4px; }
::-webkit-scrollbar-track { background: var(--bg); }
::-webkit-scrollbar-thumb { background: var(--bg-3); border-radius: 2px; }

/* ─── Noise Overlay ─── */
.noise {
  position: fixed; inset: 0; z-index: 9999;
  pointer-events: none; opacity: 0.025;
  background-image: url("data:image/svg+xml,%3Csvg viewBox='0 0 256 256' xmlns='http://www.w3.org/2000/svg'%3E%3Cfilter id='noise'%3E%3CfeTurbulence type='fractalNoise' baseFrequency='0.9' numOctaves='4' stitchTiles='stitch'/%3E%3C/filter%3E%3Crect width='100%25' height='100%25' filter='url(%23noise)'/%3E%3C/svg%3E");
  background-size: 128px;
}

/* ─── Custom Cursor ─── */
.cursor {
  position: fixed; width: 28px; height: 28px;
  border: 1.5px solid var(--accent);
  border-radius: 50%; pointer-events: none;
  z-index: 10000; transform: translate(-50%, -50%);
  transition: width 0.2s var(--ease), height 0.2s var(--ease), opacity 0.2s, border-color 0.2s;
}
.cursor-dot {
  position: fixed; width: 4px; height: 4px;
  background: var(--accent); border-radius: 50%;
  pointer-events: none; z-index: 10001;
  transform: translate(-50%, -50%);
}
body:has(a:hover) .cursor,
body:has(.case-item:hover) .cursor {
  width: 52px; height: 52px; border-color: var(--accent-2);
}

/* ─── Navigation ─── */
#nav {
  position: fixed; top: 0; left: 0; right: 0;
  height: var(--nav-h);
  display: flex; align-items: center;
  justify-content: space-between;
  padding: 0 48px; z-index: 1000;
  transition: background 0.4s, backdrop-filter 0.4s;
}
#nav.scrolled {
  background: rgba(13, 15, 20, 0.85);
  backdrop-filter: blur(16px);
  border-bottom: 1px solid var(--border);
}
.nav-logo {
  font-family: var(--font-display);
  font-size: 1.1rem; font-weight: 700;
  letter-spacing: 0.05em; color: var(--white);
  background: var(--accent-grd);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
}
.nav-links { display: flex; gap: 36px; }
.nav-links a {
  font-size: 0.82rem; font-weight: 400;
  letter-spacing: 0.04em; color: var(--gray-2);
  transition: color 0.2s;
}
.nav-links a:hover { color: var(--white); }
.nav-status {
  display: flex; align-items: center; gap: 8px;
  font-size: 0.75rem; color: var(--gray-2);
}
.status-dot {
  width: 7px; height: 7px;
  background: var(--green); border-radius: 50%;
  box-shadow: 0 0 8px var(--green);
  animation: pulse 2s ease-in-out infinite;
}
@keyframes pulse {
  0%, 100% { opacity: 1; transform: scale(1); }
  50% { opacity: 0.5; transform: scale(0.8); }
}

/* ─── Hero ─── */
#hero {
  min-height: 100vh;
  position: relative;
  display: flex; flex-direction: column;
  justify-content: flex-end;
  padding: calc(var(--nav-h) + 60px) 48px 80px;
  overflow: hidden;
}

/* Full-bleed background image with dark overlay */
.hero-bg {
  position: absolute; inset: 0; z-index: 0;
}
.hero-bg img {
  width: 100%; height: 100%;
  object-fit: cover; object-position: center top;
}
.hero-bg::after {
  content: '';
  position: absolute; inset: 0;
  background: linear-gradient(
    to right,
    rgba(13,15,20,0.92) 0%,
    rgba(13,15,20,0.75) 50%,
    rgba(13,15,20,0.35) 100%
  );
}

/* Subtle grid */
#hero::before {
  content: '';
  position: absolute; inset: 0; z-index: 1;
  background-image:
    linear-gradient(rgba(255,255,255,0.03) 1px, transparent 1px),
    linear-gradient(90deg, rgba(255,255,255,0.03) 1px, transparent 1px);
  background-size: 72px 72px;
  pointer-events: none;
}

#hero > *:not(.hero-bg) { position: relative; z-index: 2; }

.hero-eyebrow {
  display: flex; align-items: center; gap: 14px;
  font-size: 0.72rem; font-family: var(--font-mono);
  letter-spacing: 0.18em; text-transform: uppercase;
  color: var(--accent); margin-bottom: 28px;
  opacity: 0;
  animation: fadeUp 0.8s var(--ease-out) 0.2s forwards;
}
.line-decor {
  display: inline-block; width: 40px; height: 1px;
  background: var(--accent);
}

.hero-title {
  font-family: var(--font-display);
  font-size: clamp(3.5rem, 9vw, 8rem);
  font-weight: 800; line-height: 1;
  letter-spacing: -0.03em; color: var(--white);
  margin-bottom: 28px;
}
.title-line { display: block; overflow: hidden; }
.title-line.gradient {
  background: var(--accent-grd);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
}
.reveal-line {
  opacity: 0; transform: translateY(50px);
  animation: slideUp 0.9s var(--ease-out) forwards;
}
.reveal-line:nth-child(1) { animation-delay: 0.35s; }
.reveal-line:nth-child(2) { animation-delay: 0.5s; }

.hero-desc {
  font-size: 1.1rem; font-weight: 300;
  color: var(--gray-2); max-width: 420px;
  line-height: 1.7; margin-bottom: 40px;
  opacity: 0;
  animation: fadeUp 0.8s var(--ease-out) 0.7s forwards;
}

.hero-cta {
  display: flex; gap: 16px; flex-wrap: wrap;
  opacity: 0;
  animation: fadeUp 0.8s var(--ease-out) 0.9s forwards;
}
.btn-primary {
  display: inline-flex; align-items: center; gap: 8px;
  padding: 14px 28px; border-radius: 8px;
  background: var(--accent-grd);
  color: var(--white); font-size: 0.88rem; font-weight: 500;
  transition: opacity 0.2s, transform 0.2s;
}
.btn-primary:hover { opacity: 0.88; transform: translateY(-2px); }
.btn-secondary {
  display: inline-flex; align-items: center; gap: 8px;
  padding: 14px 28px; border-radius: 8px;
  border: 1px solid var(--border);
  color: var(--gray-1); font-size: 0.88rem; font-weight: 400;
  transition: border-color 0.2s, color 0.2s, transform 0.2s;
}
.btn-secondary:hover {
  border-color: var(--accent); color: var(--white);
  transform: translateY(-2px);
}

.hero-meta {
  display: flex; gap: 40px; margin-top: 64px;
  padding-top: 32px; border-top: 1px solid var(--border);
  opacity: 0;
  animation: fadeUp 0.8s var(--ease-out) 1.1s forwards;
}
.meta-item { display: flex; flex-direction: column; gap: 4px; }
.meta-label {
  font-family: var(--font-mono); font-size: 0.6rem;
  letter-spacing: 0.15em; text-transform: uppercase;
  color: var(--gray-3);
}
.meta-value { font-size: 0.88rem; color: var(--gray-1); font-weight: 400; }

.hero-scroll-hint {
  position: absolute; bottom: 48px; right: 48px; z-index: 2;
  display: flex; flex-direction: column; align-items: center; gap: 10px;
}
.hero-scroll-hint span {
  font-family: var(--font-mono); font-size: 0.58rem;
  letter-spacing: 0.2em; text-transform: uppercase;
  color: var(--gray-3); writing-mode: vertical-rl;
}
.scroll-line {
  width: 1px; height: 56px;
  background: linear-gradient(to bottom, var(--accent), transparent);
  animation: scrollDrop 1.5s ease-in-out infinite;
}
@keyframes scrollDrop {
  0%   { transform: scaleY(0); transform-origin: top; }
  50%  { transform: scaleY(1); transform-origin: top; }
  51%  { transform: scaleY(1); transform-origin: bottom; }
  100% { transform: scaleY(0); transform-origin: bottom; }
}

/* ─── Marquee ─── */
.marquee-wrap {
  overflow: hidden;
  border-top: 1px solid var(--border);
  border-bottom: 1px solid var(--border);
  padding: 18px 0; background: var(--bg-2);
}
.marquee-track {
  display: flex; white-space: nowrap;
  animation: marquee 30s linear infinite;
}
.marquee-track span {
  font-size: 0.82rem; font-weight: 400;
  color: var(--gray-3); padding: 0 20px;
  letter-spacing: 0.06em;
}
.marquee-track .dot { color: var(--accent); padding: 0; }
@keyframes marquee {
  from { transform: translateX(0); }
  to   { transform: translateX(-50%); }
}

/* ─── Section Shared ─── */
section { padding: 120px 48px; }

.section-label {
  display: flex; align-items: center; gap: 12px;
  font-family: var(--font-mono); font-size: 0.65rem;
  letter-spacing: 0.15em; text-transform: uppercase;
  color: var(--gray-3); margin-bottom: 48px;
}
.section-num { color: var(--accent); }

.section-header {
  max-width: 1200px; margin: 0 auto 64px;
  display: flex; align-items: flex-end;
  justify-content: space-between;
  border-bottom: 1px solid var(--border);
  padding-bottom: 32px;
}
.section-title {
  font-family: var(--font-display);
  font-size: clamp(2rem, 4.5vw, 3.8rem);
  font-weight: 700; letter-spacing: -0.02em;
  color: var(--white); line-height: 1.1;
}

/* ─── About ─── */
#about { background: var(--bg-2); }

.about-grid {
  max-width: 1200px; margin: 0 auto;
  display: grid; grid-template-columns: 1fr 1.6fr;
  gap: 80px; align-items: start;
}
.about-left .section-label { margin-bottom: 32px; }

.about-image-block { position: relative; }
.about-img-placeholder {
  width: 100%; aspect-ratio: 4/5;
  border-radius: var(--radius);
  overflow: hidden; position: relative;
  border: 1px solid var(--border);
}
.img-inner {
  position: absolute; inset: 0;
  background: var(--bg-3);
}
.img-inner img {
  width: 100%; height: 100%;
  object-fit: cover; object-position: center top;
}
.about-img-caption {
  margin-top: 12px; font-family: var(--font-mono);
  font-size: 0.62rem; color: var(--gray-3);
  letter-spacing: 0.1em;
}

.about-heading {
  font-family: var(--font-display);
  font-size: clamp(1.6rem, 2.8vw, 2.4rem);
  font-weight: 700; line-height: 1.3;
  color: var(--white); margin-bottom: 28px;
  letter-spacing: -0.02em;
}
.about-heading em {
  font-style: normal;
  background: var(--accent-grd);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
}
.about-body {
  font-size: 0.95rem; line-height: 1.8;
  color: var(--gray-2); margin-bottom: 20px;
  max-width: 540px;
}
.about-stats {
  display: flex; gap: 40px; margin-top: 48px;
  padding-top: 32px; border-top: 1px solid var(--border);
}
.stat-num {
  font-family: var(--font-display);
  font-size: 2.2rem; font-weight: 700;
  color: var(--white); line-height: 1; margin-bottom: 4px;
  background: var(--accent-grd);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
}
.stat-label {
  font-family: var(--font-mono); font-size: 0.6rem;
  letter-spacing: 0.12em; text-transform: uppercase;
  color: var(--gray-3);
}

/* ─── Work / Cases ─── */
#work { background: var(--bg); }

.cases-list { max-width: 1200px; margin: 0 auto; }

.case-item {
  display: grid;
  grid-template-columns: 180px 1fr 140px 32px;
  align-items: center; gap: 32px;
  padding: 32px 24px;
  border-bottom: 1px solid var(--border);
  border-radius: var(--radius);
  transition: background 0.25s;
  cursor: default; position: relative;
}
.case-item:hover { background: var(--bg-card); }

.case-meta { display: flex; flex-direction: column; gap: 6px; }
.case-tag {
  font-family: var(--font-mono); font-size: 0.6rem;
  letter-spacing: 0.1em; text-transform: uppercase;
  color: var(--accent);
  background: rgba(79,142,247,0.1);
  padding: 3px 10px; border-radius: 4px;
  display: inline-block;
}
.case-year {
  font-family: var(--font-mono); font-size: 0.65rem;
  color: var(--gray-3);
}
.case-title {
  font-family: var(--font-display);
  font-size: 1.35rem; font-weight: 600;
  letter-spacing: -0.01em; color: var(--white);
  margin-bottom: 8px; transition: color 0.2s;
}
.case-item:hover .case-title { color: var(--accent); }
.case-desc {
  font-size: 0.84rem; line-height: 1.7;
  color: var(--gray-2); max-width: 480px;
}
.case-result { text-align: right; }
.result-label {
  display: block; font-family: var(--font-mono);
  font-size: 0.55rem; letter-spacing: 0.12em;
  text-transform: uppercase; color: var(--gray-3); margin-bottom: 4px;
}
.result-val {
  font-family: var(--font-display);
  font-size: 1.5rem; font-weight: 700; color: var(--white);
}
.case-arrow {
  font-size: 1.1rem; color: var(--gray-3);
  transition: transform 0.3s, color 0.2s; text-align: center;
}
.case-item:hover .case-arrow {
  transform: translate(5px, -5px); color: var(--accent);
}

/* ─── Expertise ─── */
#expertise { background: var(--bg-2); }

.expertise-grid {
  max-width: 1200px; margin: 0 auto;
  display: grid; grid-template-columns: repeat(3, 1fr);
  gap: 16px;
}
.exp-card {
  background: var(--bg-card);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 40px 32px;
  transition: border-color 0.3s, transform 0.3s;
  position: relative; overflow: hidden;
}
.exp-card::before {
  content: '';
  position: absolute; top: 0; left: 0; right: 0;
  height: 2px;
  background: var(--accent-grd);
  transform: scaleX(0); transform-origin: left;
  transition: transform 0.3s var(--ease);
}
.exp-card:hover {
  border-color: rgba(79,142,247,0.3);
  transform: translateY(-4px);
}
.exp-card:hover::before { transform: scaleX(1); }

.exp-icon {
  font-size: 1.4rem; margin-bottom: 20px;
  display: block;
  background: var(--accent-grd);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
}
.exp-card h3 {
  font-family: var(--font-display);
  font-size: 1.15rem; font-weight: 600;
  color: var(--white); margin-bottom: 12px;
}
.exp-card p {
  font-size: 0.84rem; line-height: 1.7;
  color: var(--gray-2); margin-bottom: 20px;
}
.exp-tags { display: flex; flex-wrap: wrap; gap: 6px; }
.exp-tags span {
  font-family: var(--font-mono); font-size: 0.58rem;
  letter-spacing: 0.08em; text-transform: uppercase;
  color: var(--accent);
  border: 1px solid rgba(79,142,247,0.25);
  padding: 3px 8px; border-radius: 4px;
}

/* ─── Timeline ─── */
#experience { background: var(--bg); }

.timeline {
  max-width: 900px; margin: 0 auto; position: relative;
}
.timeline::before {
  content: '';
  position: absolute; left: 160px; top: 0; bottom: 0;
  width: 1px; background: var(--border);
}
.tl-item {
  display: grid; grid-template-columns: 160px 1fr;
  gap: 48px; padding: 40px 0;
  border-bottom: 1px solid var(--border);
  position: relative;
}
.tl-item::before {
  content: '';
  position: absolute; left: 154px; top: 48px;
  width: 11px; height: 11px;
  background: var(--accent); border-radius: 50%;
  border: 2px solid var(--bg);
  box-shadow: 0 0 10px rgba(79,142,247,0.5);
}
.tl-period {
  font-family: var(--font-mono); font-size: 0.65rem;
  letter-spacing: 0.1em; color: var(--gray-3);
  padding-top: 4px; text-align: right; padding-right: 32px;
}
.tl-role {
  font-family: var(--font-display);
  font-size: 1.25rem; font-weight: 600;
  color: var(--white); margin-bottom: 4px;
}
.tl-company {
  font-family: var(--font-mono); font-size: 0.68rem;
  letter-spacing: 0.08em; color: var(--accent);
  text-transform: uppercase; margin-bottom: 12px;
}
.tl-detail {
  font-size: 0.85rem; line-height: 1.7;
  color: var(--gray-2); max-width: 500px;
}

/* ─── Contact ─── */
#contact {
  background: var(--bg-2);
  padding: 140px 48px; text-align: center;
  position: relative; overflow: hidden;
}
#contact::before {
  content: '';
  position: absolute; top: -200px; left: 50%;
  transform: translateX(-50%);
  width: 600px; height: 600px;
  background: radial-gradient(circle, rgba(79,142,247,0.08) 0%, transparent 70%);
  pointer-events: none;
}
.contact-inner { max-width: 680px; margin: 0 auto; position: relative; }
#contact .section-label { justify-content: center; }
.contact-heading {
  font-family: var(--font-display);
  font-size: clamp(3rem, 7vw, 6rem);
  font-weight: 800; line-height: 1.05;
  color: var(--white); letter-spacing: -0.03em;
  margin-bottom: 24px;
}
.contact-heading em {
  font-style: normal;
  background: var(--accent-grd);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
}
.contact-sub {
  font-size: 0.95rem; line-height: 1.7;
  color: var(--gray-2); max-width: 420px;
  margin: 0 auto 48px;
}
.contact-email {
  display: inline-block;
  font-size: 1.2rem; font-weight: 500;
  color: var(--white);
  border-bottom: 1px solid rgba(79,142,247,0.4);
  padding-bottom: 4px; margin-bottom: 48px;
  transition: color 0.2s, border-color 0.2s;
}
.contact-email:hover { color: var(--accent); border-color: var(--accent); }
.contact-links {
  display: flex; align-items: center;
  justify-content: center; gap: 20px;
}
.contact-link {
  font-family: var(--font-mono); font-size: 0.68rem;
  letter-spacing: 0.1em; text-transform: uppercase;
  color: var(--gray-2); transition: color 0.2s;
}
.contact-link:hover { color: var(--white); }
.divider { color: var(--accent); }

/* ─── Footer ─── */
footer {
  background: var(--bg);
  border-top: 1px solid var(--border);
  padding: 28px 48px;
  display: flex; align-items: center;
  justify-content: space-between;
}
footer span, footer div {
  font-family: var(--font-mono); font-size: 0.62rem;
  letter-spacing: 0.1em; color: var(--gray-3);
}
.footer-center {
  font-family: var(--font-display) !important;
  font-size: 1rem !important; font-weight: 700;
  background: var(--accent-grd);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
}

/* ─── Scroll Animations ─── */
.fade-in-up {
  opacity: 0; transform: translateY(28px);
  transition: opacity 0.7s var(--ease-out), transform 0.7s var(--ease-out);
}
.fade-in-up.visible { opacity: 1; transform: translateY(0); }

/* ─── Keyframes ─── */
@keyframes fadeUp {
  from { opacity: 0; transform: translateY(20px); }
  to   { opacity: 1; transform: translateY(0); }
}
@keyframes slideUp {
  from { opacity: 0; transform: translateY(50px); }
  to   { opacity: 1; transform: translateY(0); }
}

/* ─── Responsive ─── */
@media (max-width: 900px) {
  #nav { padding: 0 24px; }
  .nav-links, .nav-status { display: none; }

  section { padding: 80px 24px; }
  #hero { padding: calc(var(--nav-h) + 40px) 24px 60px; }

  .hero-title { font-size: clamp(3rem, 14vw, 5rem); }
  .hero-meta { gap: 24px; flex-wrap: wrap; }

  .about-grid { grid-template-columns: 1fr; gap: 48px; }
  .about-stats { gap: 24px; }

  .case-item { grid-template-columns: 1fr; gap: 12px; }
  .case-result { text-align: left; }
  .case-arrow { display: none; }

  .expertise-grid { grid-template-columns: 1fr; }

  .timeline::before { left: 0; }
  .tl-item { grid-template-columns: 1fr; gap: 8px; }
  .tl-item::before { display: none; }
  .tl-period { text-align: left; padding-right: 0; }

  .section-header { flex-direction: column; align-items: flex-start; gap: 16px; }
}

/* ════════════════════════════════════════
   UPDATES: Badge · Dark Mode · Projects · CFA · Springer
   ════════════════════════════════════════ */

/* ─── Nav Right Group ─── */
.nav-right {
  display: flex; align-items: center; gap: 16px;
}

/* ─── Open to Work Badge ─── */
.otw-badge {
  display: flex; align-items: center; gap: 7px;
  padding: 6px 14px;
  background: rgba(61, 214, 140, 0.1);
  border: 1px solid rgba(61, 214, 140, 0.3);
  border-radius: 999px;
  font-size: 0.72rem; font-weight: 500;
  color: #3DD68C;
  letter-spacing: 0.03em;
  white-space: nowrap;
}
.otw-dot {
  width: 7px; height: 7px;
  background: #3DD68C; border-radius: 50%;
  box-shadow: 0 0 6px #3DD68C;
  animation: otw-pulse 1.8s ease-in-out infinite;
  flex-shrink: 0;
}
@keyframes otw-pulse {
  0%, 100% { opacity: 1; transform: scale(1); box-shadow: 0 0 6px #3DD68C; }
  50%       { opacity: 0.6; transform: scale(0.75); box-shadow: 0 0 2px #3DD68C; }
}

/* ─── Dark Mode Toggle ─── */
.theme-toggle {
  display: flex; align-items: center; justify-content: center;
  width: 36px; height: 36px;
  background: var(--bg-card);
  border: 1px solid var(--border);
  border-radius: 8px;
  color: var(--gray-2);
  cursor: pointer;
  transition: color 0.2s, border-color 0.2s, background 0.2s;
  flex-shrink: 0;
}
.theme-toggle:hover { color: var(--white); border-color: var(--accent); }

/* Show/hide sun & moon based on theme */
[data-theme="dark"]  .icon-sun  { display: block; }
[data-theme="dark"]  .icon-moon { display: none; }
[data-theme="light"] .icon-sun  { display: none; }
[data-theme="light"] .icon-moon { display: block; }

/* ─── Light Mode Variables ─── */
[data-theme="light"] {
  --bg:        #F5F7FA;
  --bg-2:      #FFFFFF;
  --bg-3:      #EEF1F6;
  --bg-card:   #FFFFFF;
  --border:    rgba(0,0,0,0.08);
  --white:     #0D0F14;
  --gray-1:    #1A1E2A;
  --gray-2:    #4A5068;
  --gray-3:    #8A90A4;
}
[data-theme="light"] #nav.scrolled {
  background: rgba(245, 247, 250, 0.9);
}
[data-theme="light"] .hero-bg::after {
  background: linear-gradient(
    to right,
    rgba(245,247,250,0.95) 0%,
    rgba(245,247,250,0.80) 50%,
    rgba(245,247,250,0.45) 100%
  );
}
[data-theme="light"] #hero::before {
  background-image:
    linear-gradient(rgba(0,0,0,0.04) 1px, transparent 1px),
    linear-gradient(90deg, rgba(0,0,0,0.04) 1px, transparent 1px);
}
[data-theme="light"] .tl-item::before {
  border-color: var(--bg);
}
[data-theme="light"] ::-webkit-scrollbar-track { background: var(--bg); }
[data-theme="light"] ::-webkit-scrollbar-thumb { background: var(--bg-3); }

/* Smooth theme transition */
body, #nav, section, footer, .exp-card, .project-card, .case-item, .tl-item {
  transition: background-color 0.3s ease, color 0.3s ease, border-color 0.3s ease;
}

/* ─── Projects Section ─── */
#projects { background: var(--bg-2); }

.projects-grid {
  max-width: 1200px; margin: 0 auto;
  display: grid; grid-template-columns: repeat(3, 1fr);
  gap: 20px;
}

.project-card {
  background: var(--bg-card);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 32px 28px;
  display: flex; flex-direction: column; gap: 16px;
  transition: border-color 0.3s, transform 0.3s;
}
.project-card:hover {
  border-color: rgba(79,142,247,0.3);
  transform: translateY(-4px);
}

.project-card-top {
  display: flex; align-items: center;
  justify-content: space-between;
}

.project-file-tag {
  font-family: var(--font-mono); font-size: 0.6rem;
  letter-spacing: 0.1em; text-transform: uppercase;
  padding: 3px 10px; border-radius: 4px; font-weight: 500;
}
.project-file-tag.pdf    { background: rgba(239,68,68,0.12);  color: #F87171; border: 1px solid rgba(239,68,68,0.2); }
.project-file-tag.report { background: rgba(79,142,247,0.12); color: var(--accent); border: 1px solid rgba(79,142,247,0.2); }
.project-file-tag.excel  { background: rgba(34,197,94,0.12);  color: #4ADE80; border: 1px solid rgba(34,197,94,0.2); }

.project-status.coming-soon {
  font-family: var(--font-mono); font-size: 0.6rem;
  letter-spacing: 0.08em; color: var(--gray-3);
}

.project-title {
  font-family: var(--font-display);
  font-size: 1.1rem; font-weight: 600;
  color: var(--white); line-height: 1.3;
}

.project-desc {
  font-size: 0.84rem; line-height: 1.7;
  color: var(--gray-2); flex: 1;
}

.project-footer {
  display: flex; align-items: center;
  justify-content: space-between; gap: 12px;
  margin-top: auto; padding-top: 16px;
  border-top: 1px solid var(--border);
}

.project-tags {
  display: flex; flex-wrap: wrap; gap: 5px;
}
.project-tags span {
  font-family: var(--font-mono); font-size: 0.55rem;
  letter-spacing: 0.08em; text-transform: uppercase;
  color: var(--accent);
  border: 1px solid rgba(79,142,247,0.2);
  padding: 2px 7px; border-radius: 4px;
}

.btn-view-project {
  font-family: var(--font-mono); font-size: 0.65rem;
  letter-spacing: 0.08em; text-transform: uppercase;
  padding: 7px 14px; border-radius: 6px;
  border: 1px solid var(--border);
  color: var(--gray-3); background: transparent;
  cursor: not-allowed; white-space: nowrap;
  flex-shrink: 0;
}
.btn-view-project:disabled { opacity: 0.5; }

.projects-note {
  max-width: 1200px; margin: 32px auto 0;
  text-align: center;
  font-family: var(--font-mono); font-size: 0.65rem;
  letter-spacing: 0.1em; color: var(--gray-3);
}

/* ─── CFA Digital Badge ─── */
.cfa-badge-wrap { margin-top: 20px; }

.cfa-badge-link { display: inline-block; }

.cfa-badge {
  display: inline-flex; align-items: center; gap: 12px;
  padding: 12px 18px;
  background: rgba(79,142,247,0.08);
  border: 1px solid rgba(79,142,247,0.25);
  border-radius: 10px;
  transition: border-color 0.2s, background 0.2s;
}
.cfa-badge-link:hover .cfa-badge {
  border-color: var(--accent);
  background: rgba(79,142,247,0.14);
}

.cfa-badge-icon {
  width: 36px; height: 36px;
  background: var(--accent-grd);
  border-radius: 8px;
  display: flex; align-items: center; justify-content: center;
  color: #fff; flex-shrink: 0;
}

.cfa-badge-text {
  display: flex; flex-direction: column; gap: 2px;
}
.cfa-badge-title {
  font-size: 0.88rem; font-weight: 600; color: var(--white);
}
.cfa-badge-sub {
  font-family: var(--font-mono); font-size: 0.62rem;
  color: var(--gray-2); letter-spacing: 0.06em;
}

.cfa-badge-verify {
  font-family: var(--font-mono); font-size: 0.62rem;
  color: var(--accent); letter-spacing: 0.06em;
  margin-left: 8px;
}

/* ─── Springer Badge & View Paper Button ─── */
.tl-role-row {
  display: flex; align-items: center; gap: 10px;
  flex-wrap: wrap; margin-bottom: 4px;
}

.springer-badge {
  display: inline-block;
  font-family: var(--font-mono); font-size: 0.58rem;
  letter-spacing: 0.08em; text-transform: uppercase;
  font-weight: 600;
  padding: 3px 9px; border-radius: 4px;
  background: rgba(232,119,34,0.15);
  color: #F97316;
  border: 1px solid rgba(232,119,34,0.3);
}

.btn-view-paper {
  display: inline-flex; align-items: center; gap: 6px;
  margin-top: 14px;
  padding: 8px 18px; border-radius: 7px;
  border: 1px solid rgba(232,119,34,0.35);
  color: #F97316; font-size: 0.82rem; font-weight: 500;
  background: rgba(232,119,34,0.08);
  transition: background 0.2s, border-color 0.2s, color 0.2s;
}
.btn-view-paper:hover {
  background: rgba(232,119,34,0.16);
  border-color: #F97316; color: #FB923C;
}

/* ─── Responsive updates ─── */
@media (max-width: 900px) {
  .nav-right { gap: 10px; }
  .otw-badge { display: none; }

  .projects-grid { grid-template-columns: 1fr; }

  .tl-role-row { flex-direction: column; align-items: flex-start; gap: 6px; }
}