/* ===== CSS Custom Properties ===== */
:root {
  --color-bg: #fafafa;
  --color-bg-alt: #f0f0f0;
  --color-text: #2d2d2d;
  --color-text-light: #6b6b6b;
  --color-accent: #3d7c8a;
  --color-accent-hover: #2e6270;
  --color-white: #ffffff;
  --color-border: #e0e0e0;
  --font-family: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', sans-serif;
  --nav-height: 64px;
  --container-max: 1080px;
  --transition: 0.3s ease;
}

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

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

body {
  font-family: var(--font-family);
  font-size: 16px;
  line-height: 1.7;
  color: var(--color-text);
  background-color: var(--color-bg);
  -webkit-font-smoothing: antialiased;
}

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

a {
  color: var(--color-accent);
  text-decoration: none;
  transition: color var(--transition);
}

a:hover {
  color: var(--color-accent-hover);
}

h1, h2, h3, h4 {
  line-height: 1.3;
  font-weight: 600;
}

/* ===== Container ===== */
.container {
  max-width: var(--container-max);
  margin: 0 auto;
  padding: 0 24px;
}

/* ===== Navigation ===== */
.nav {
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  height: var(--nav-height);
  background: rgba(250, 250, 250, 0.92);
  backdrop-filter: blur(12px);
  -webkit-backdrop-filter: blur(12px);
  border-bottom: 1px solid var(--color-border);
  z-index: 1000;
  transition: box-shadow var(--transition);
}

.nav--scrolled {
  box-shadow: 0 1px 8px rgba(0, 0, 0, 0.06);
}

.nav__inner {
  max-width: var(--container-max);
  margin: 0 auto;
  padding: 0 24px;
  height: 100%;
  display: flex;
  align-items: center;
  justify-content: space-between;
}

.nav__logo {
  font-size: 1.15rem;
  font-weight: 700;
  color: var(--color-text);
  letter-spacing: -0.02em;
}

.nav__logo:hover {
  color: var(--color-accent);
}

.nav__links {
  list-style: none;
  display: flex;
  gap: 32px;
}

.nav__links a {
  color: var(--color-text-light);
  font-size: 0.9rem;
  font-weight: 500;
  transition: color var(--transition);
}

.nav__links a:hover,
.nav__links a.active {
  color: var(--color-accent);
}

/* Hamburger */
.nav__toggle {
  display: none;
  flex-direction: column;
  gap: 5px;
  background: none;
  border: none;
  cursor: pointer;
  padding: 4px;
}

.nav__toggle span {
  display: block;
  width: 24px;
  height: 2px;
  background: var(--color-text);
  border-radius: 2px;
  transition: transform var(--transition), opacity var(--transition);
}

.nav__toggle.open span:nth-child(1) {
  transform: translateY(7px) rotate(45deg);
}

.nav__toggle.open span:nth-child(2) {
  opacity: 0;
}

.nav__toggle.open span:nth-child(3) {
  transform: translateY(-7px) rotate(-45deg);
}

/* ===== Hero ===== */
.hero {
  min-height: 100vh;
  display: flex;
  align-items: center;
  justify-content: center;
  text-align: center;
  padding: calc(var(--nav-height) + 40px) 24px 80px;
  position: relative;
  overflow: hidden;
}

/* --- Particle Dot Background --- */
.hero--particles {
  background: linear-gradient(180deg, #f4f8f9 0%, #fafafa 100%);
}

#hero-particles-canvas {
  position: absolute;
  inset: 0;
  width: 100%;
  height: 100%;
  z-index: 0;
  pointer-events: none;
  display: none;
}

.hero--particles #hero-particles-canvas {
  display: block;
}

.hero--particles .hero__content {
  position: relative;
  z-index: 1;
}


.hero__title {
  font-size: clamp(2rem, 5vw, 3.5rem);
  font-weight: 700;
  letter-spacing: -0.03em;
  margin-bottom: 12px;
}

.accent {
  color: var(--color-accent);
}

.hero__subtitle {
  font-size: clamp(1.1rem, 2.5vw, 1.5rem);
  color: var(--color-text-light);
  font-weight: 400;
  margin-bottom: 8px;
}

.hero__tagline {
  font-size: clamp(0.95rem, 2vw, 1.15rem);
  color: var(--color-text-light);
  max-width: 560px;
  margin: 0 auto 32px;
  line-height: 1.6;
}

/* Typed cursor */
.typed-cursor {
  font-weight: 300;
  color: var(--color-accent);
  animation: blink 1s step-end infinite;
}

@keyframes blink {
  0%, 100% { opacity: 1; }
  50% { opacity: 0; }
}

/* Status indicator */
.hero__status {
  display: inline-flex;
  align-items: center;
  gap: 10px;
  font-size: 0.9rem;
  font-weight: 600;
  color: #166534;
  margin-bottom: 28px;
  padding: 10px 20px;
  background: rgba(220, 252, 231, 0.85);
  border: 1px solid rgba(34, 197, 94, 0.3);
  border-radius: 24px;
  backdrop-filter: blur(4px);
  -webkit-backdrop-filter: blur(4px);
}

.hero__status-dot {
  width: 10px;
  height: 10px;
  background: #22c55e;
  border-radius: 50%;
  flex-shrink: 0;
  animation: pulse-dot 2s ease-in-out infinite;
}

@keyframes pulse-dot {
  0%, 100% { box-shadow: 0 0 0 0 rgba(34, 197, 94, 0.5); }
  50% { box-shadow: 0 0 0 6px rgba(34, 197, 94, 0); }
}

.hero__social {
  display: flex;
  gap: 20px;
  justify-content: center;
  margin-bottom: 40px;
}

.hero__social a {
  color: var(--color-text-light);
  transition: color var(--transition), transform var(--transition);
}

.hero__social a:hover {
  color: var(--color-accent);
  transform: translateY(-2px);
}

.hero__cta {
  display: inline-block;
  padding: 12px 32px;
  background: var(--color-accent);
  color: var(--color-white);
  font-weight: 600;
  font-size: 0.95rem;
  border-radius: 6px;
  transition: background var(--transition), transform var(--transition);
}

.hero__cta:hover {
  background: var(--color-accent-hover);
  color: var(--color-white);
  transform: translateY(-1px);
}

/* ===== Sections ===== */
.section {
  padding: 96px 0;
}

.section--alt {
  background: var(--color-bg-alt);
}

.section__title {
  font-size: 2rem;
  text-align: center;
  margin-bottom: 56px;
  letter-spacing: -0.02em;
}

.section__title::after {
  content: '';
  display: block;
  width: 48px;
  height: 3px;
  background: var(--color-accent);
  margin: 16px auto 0;
  border-radius: 2px;
}

/* ===== About ===== */
.about__grid {
  display: grid;
  grid-template-columns: 240px 1fr;
  gap: 48px;
  align-items: start;
}

.about__photo {
  width: 240px;
  height: 240px;
  border-radius: 12px;
  box-shadow: 0 4px 20px rgba(0, 0, 0, 0.08);
  overflow: hidden;
  flex-shrink: 0;
}

.about__photo img {
  width: 100%;
  height: 100%;
  object-fit: cover;
  object-position: 55% 30%;
  transform: scale(1.8);
  transform-origin: 55% 30%;
}

.about__text p {
  margin-bottom: 16px;
}

.about__contact {
  margin: 24px 0;
  padding: 16px 20px;
  background: var(--color-bg-alt);
  border-radius: 8px;
}

.about__contact p {
  margin-bottom: 4px;
  font-size: 0.95rem;
}

/* ===== Button ===== */
.btn {
  display: inline-block;
  padding: 12px 28px;
  background: var(--color-accent);
  color: var(--color-white);
  font-weight: 600;
  font-size: 0.9rem;
  border-radius: 6px;
  transition: background var(--transition), transform var(--transition);
}

.btn:hover {
  background: var(--color-accent-hover);
  color: var(--color-white);
  transform: translateY(-1px);
}

.btn--large {
  padding: 16px 40px;
  font-size: 1rem;
}

/* ===== Timeline ===== */
.timeline__category {
  font-size: 1.2rem;
  color: var(--color-accent);
  margin-bottom: 32px;
  padding-left: 24px;
}

.timeline {
  position: relative;
  padding-left: 24px;
  margin-bottom: 56px;
}


/* Grouped employer */
.timeline__group {
  position: relative;
  padding-left: 32px;
  padding-bottom: 40px;
}

.timeline__group:last-child {
  padding-bottom: 0;
}

.timeline__group-header {
  margin-bottom: 24px;
}

.timeline__group-company {
  font-size: 1.15rem;
  font-weight: 700;
  margin-bottom: 2px;
}

.timeline__group-meta {
  font-size: 0.85rem;
  color: var(--color-text-light);
}

.timeline__group-roles {
  position: relative;
  padding-left: 20px;
  border-left: 2px solid var(--color-border);
}

.timeline__group-roles .timeline__item {
  padding-left: 24px;
  padding-bottom: 32px;
}

.timeline__group-roles .timeline__item:last-child {
  padding-bottom: 0;
}

.timeline__group-roles .timeline__marker {
  left: -7px;
  width: 12px;
  height: 12px;
}

.timeline__item {
  position: relative;
  padding-left: 32px;
  padding-bottom: 40px;
}

.timeline__item:last-child {
  padding-bottom: 0;
}

.timeline__marker {
  position: absolute;
  left: -5px;
  top: 8px;
  width: 12px;
  height: 12px;
  background: var(--color-accent);
  border-radius: 50%;
  border: 2px solid var(--color-bg-alt);
}

.timeline__content h4 {
  font-size: 1.1rem;
  margin-bottom: 4px;
}

.timeline__meta {
  font-size: 0.85rem;
  color: var(--color-text-light);
  margin-bottom: 8px;
}

.timeline__content p:last-child:not(.timeline__meta) {
  font-size: 0.95rem;
  color: var(--color-text);
}

.timeline__list {
  margin: 4px 0 0;
  padding-left: 18px;
  font-size: 0.95rem;
  color: var(--color-text);
}

.timeline__list li {
  margin-bottom: 8px;
}

.timeline__list li:last-child {
  margin-bottom: 0;
}

.timeline__list ul {
  margin-top: 6px;
  padding-left: 18px;
  list-style-type: circle;
}

.timeline__list ul li {
  margin-bottom: 4px;
  font-size: 0.9rem;
  color: var(--color-text-light);
}

/* ===== Skills ===== */
.skills {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 40px;
}

.skills__group h3 {
  font-size: 1rem;
  color: var(--color-text-light);
  margin-bottom: 16px;
  text-transform: uppercase;
  letter-spacing: 0.05em;
  font-weight: 600;
}

.skills__chips {
  display: flex;
  flex-wrap: wrap;
  gap: 10px;
}

.chip {
  display: inline-block;
  padding: 6px 16px;
  background: var(--color-white);
  border: 1px solid var(--color-border);
  border-radius: 24px;
  font-size: 0.85rem;
  font-weight: 500;
  color: var(--color-text);
  transition: border-color var(--transition), background var(--transition);
}

.chip:hover {
  border-color: var(--color-accent);
  background: rgba(61, 124, 138, 0.05);
}

/* ===== Publications ===== */
.pub-card {
  background: var(--color-white);
  border: 1px solid var(--color-border);
  border-radius: 12px;
  padding: 32px;
  max-width: 700px;
  margin: 0 auto;
  transition: box-shadow var(--transition);
}

.pub-card:hover {
  box-shadow: 0 4px 20px rgba(0, 0, 0, 0.06);
}

.pub-card h3 {
  font-size: 1.15rem;
  margin-bottom: 8px;
}

.pub-card__meta {
  font-size: 0.85rem;
  color: var(--color-text-light);
  margin-bottom: 12px;
}

.pub-card p:not(.pub-card__meta) {
  font-size: 0.95rem;
  margin-bottom: 16px;
}

.pub-card__link {
  font-weight: 600;
  font-size: 0.9rem;
}

/* ===== Project Cards ===== */
.project-card {
  background: var(--color-white);
  border: 1px solid var(--color-border);
  border-left: 4px solid var(--color-accent);
  border-radius: 12px;
  padding: 36px;
  margin-bottom: 24px;
  transition: box-shadow var(--transition);
}

.project-card:hover {
  box-shadow: 0 4px 24px rgba(0, 0, 0, 0.07);
}

/* Status Badges */
.project-badge {
  display: inline-block;
  padding: 3px 12px;
  border-radius: 4px;
  font-size: 0.75rem;
  font-weight: 700;
  text-transform: uppercase;
  letter-spacing: 0.06em;
  margin-bottom: 16px;
}

.project-badge--in-progress {
  background: rgba(220, 252, 231, 0.85);
  color: #166534;
  border: 1px solid rgba(34, 197, 94, 0.3);
}

.project-badge--done {
  background: #dcfce7;
  color: #15803d;
}

.project-badge--planned {
  background: #f3f4f6;
  color: #6b7280;
}

.project-card__title {
  font-size: 1.4rem;
  margin-bottom: 6px;
  letter-spacing: -0.02em;
}

.project-card__tagline {
  font-size: 1rem;
  color: var(--color-accent);
  font-style: italic;
  margin-bottom: 16px;
}

.project-card__desc {
  font-size: 0.95rem;
  color: var(--color-text-light);
  margin-bottom: 20px;
  line-height: 1.7;
}

.project-card__highlights {
  margin: 0 0 24px 0;
  padding: 0;
  list-style: none;
}

.project-card__highlights li {
  position: relative;
  padding-left: 20px;
  font-size: 0.95rem;
  color: var(--color-text);
  margin-bottom: 10px;
  line-height: 1.6;
}

.project-card__highlights li::before {
  content: '→';
  position: absolute;
  left: 0;
  color: var(--color-accent);
  font-weight: 600;
}

.project-card__chips {
  margin-bottom: 28px;
}

/* ===== Contact ===== */
.contact {
  text-align: center;
}

.contact__content p {
  font-size: 1.1rem;
  color: var(--color-text-light);
  max-width: 500px;
  margin: 0 auto 32px;
}

.contact__social {
  display: flex;
  gap: 24px;
  justify-content: center;
  margin-top: 32px;
}

.contact__social a {
  color: var(--color-text-light);
  transition: color var(--transition), transform var(--transition);
}

.contact__social a:hover {
  color: var(--color-accent);
  transform: translateY(-2px);
}

/* ===== Footer ===== */
.footer {
  padding: 32px 0;
  border-top: 1px solid var(--color-border);
}

.footer__inner {
  display: flex;
  align-items: center;
  justify-content: space-between;
}

.footer__inner p {
  font-size: 0.85rem;
  color: var(--color-text-light);
}

.footer__social {
  display: flex;
  gap: 16px;
}

.footer__social a {
  color: var(--color-text-light);
  transition: color var(--transition);
}

.footer__social a:hover {
  color: var(--color-accent);
}

/* ===== Fade-in Animation ===== */
.fade-in {
  opacity: 0;
  transform: translateY(24px);
  transition: opacity 0.6s ease, transform 0.6s ease;
}

.fade-in.visible {
  opacity: 1;
  transform: translateY(0);
}

/* ===== Responsive ===== */
@media (max-width: 768px) {
  .nav__toggle {
    display: flex;
  }

  .nav__links {
    position: fixed;
    top: var(--nav-height);
    left: 0;
    right: 0;
    background: var(--color-bg);
    flex-direction: column;
    gap: 0;
    padding: 8px 0;
    border-bottom: 1px solid var(--color-border);
    box-shadow: 0 4px 12px rgba(0, 0, 0, 0.06);
    transform: translateY(-100%);
    opacity: 0;
    pointer-events: none;
    transition: transform var(--transition), opacity var(--transition);
  }

  .nav__links.open {
    transform: translateY(0);
    opacity: 1;
    pointer-events: auto;
  }

  .nav__links a {
    display: block;
    padding: 12px 24px;
  }

  .about__grid {
    grid-template-columns: 1fr;
    gap: 32px;
    text-align: center;
    justify-items: center;
  }

  .about__photo {
    width: 180px;
    height: 180px;
  }

  .section {
    padding: 64px 0;
  }

  .section__title {
    margin-bottom: 40px;
  }

  .skills {
    grid-template-columns: 1fr;
    gap: 32px;
  }

  .footer__inner {
    flex-direction: column;
    gap: 16px;
    text-align: center;
  }

  .pub-card {
    padding: 24px;
  }
}

@media (max-width: 480px) {
  .hero__title {
    font-size: 1.75rem;
  }

  .hero__cta {
    padding: 10px 24px;
    font-size: 0.9rem;
  }
}