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

:root {
  --clr-bg: #060e1a;
  --clr-surface: #0d1a2d;
  --clr-surface-2: #111f35;
  --clr-border: #1a3050;
  --clr-accent: #0ea5c5;
  --clr-accent-light: #38bdf8;
  --clr-accent-dim: rgba(14, 165, 197, 0.12);
  --clr-text: #e2eaf4;
  --clr-muted: #7a9ab8;
  --radius: 12px;
  --transition: 0.2s ease;
  --max-w: 1100px;
}

html { scroll-behavior: smooth; }

body {
  font-family: 'Segoe UI', system-ui, -apple-system, sans-serif;
  background-color: var(--clr-bg);
  background-image:
    radial-gradient(ellipse 70% 55% at 15% 20%, rgba(14, 165, 197, 0.16) 0%, transparent 55%),
    radial-gradient(ellipse 55% 45% at 85% 70%, rgba(56, 189, 248, 0.11) 0%, transparent 50%),
    radial-gradient(ellipse 50% 60% at 50% 50%, rgba(14, 165, 197, 0.07) 0%, transparent 65%),
    radial-gradient(ellipse 40% 35% at 10% 80%, rgba(99, 102, 241, 0.07) 0%, transparent 50%),
    url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' width='600' height='600'%3E%3Ccircle cx='45' cy='32' r='0.7' fill='white' opacity='0.7'/%3E%3Ccircle cx='120' cy='88' r='0.5' fill='white' opacity='0.5'/%3E%3Ccircle cx='230' cy='15' r='0.9' fill='white' opacity='0.6'/%3E%3Ccircle cx='310' cy='55' r='0.6' fill='white' opacity='0.8'/%3E%3Ccircle cx='415' cy='20' r='0.8' fill='white' opacity='0.5'/%3E%3Ccircle cx='530' cy='70' r='0.5' fill='white' opacity='0.7'/%3E%3Ccircle cx='580' cy='40' r='0.7' fill='white' opacity='0.6'/%3E%3Ccircle cx='75' cy='150' r='0.6' fill='white' opacity='0.5'/%3E%3Ccircle cx='190' cy='175' r='0.9' fill='white' opacity='0.7'/%3E%3Ccircle cx='340' cy='130' r='0.5' fill='white' opacity='0.6'/%3E%3Ccircle cx='460' cy='160' r='0.8' fill='white' opacity='0.5'/%3E%3Ccircle cx='560' cy='140' r='0.6' fill='white' opacity='0.7'/%3E%3Ccircle cx='25' cy='260' r='0.7' fill='white' opacity='0.6'/%3E%3Ccircle cx='155' cy='290' r='0.5' fill='white' opacity='0.5'/%3E%3Ccircle cx='270' cy='240' r='0.9' fill='white' opacity='0.7'/%3E%3Ccircle cx='390' cy='275' r='0.6' fill='white' opacity='0.6'/%3E%3Ccircle cx='510' cy='220' r='0.7' fill='white' opacity='0.5'/%3E%3Ccircle cx='590' cy='300' r='0.5' fill='white' opacity='0.7'/%3E%3Ccircle cx='80' cy='380' r='0.8' fill='white' opacity='0.6'/%3E%3Ccircle cx='200' cy='350' r='0.6' fill='white' opacity='0.5'/%3E%3Ccircle cx='320' cy='400' r='0.9' fill='white' opacity='0.7'/%3E%3Ccircle cx='440' cy='370' r='0.5' fill='white' opacity='0.6'/%3E%3Ccircle cx='555' cy='420' r='0.7' fill='white' opacity='0.5'/%3E%3Ccircle cx='35' cy='470' r='0.6' fill='white' opacity='0.7'/%3E%3Ccircle cx='160' cy='500' r='0.8' fill='white' opacity='0.6'/%3E%3Ccircle cx='280' cy='460' r='0.5' fill='white' opacity='0.5'/%3E%3Ccircle cx='400' cy='490' r='0.7' fill='white' opacity='0.7'/%3E%3Ccircle cx='520' cy='480' r='0.9' fill='white' opacity='0.5'/%3E%3Ccircle cx='590' cy='550' r='0.6' fill='white' opacity='0.6'/%3E%3Ccircle cx='100' cy='560' r='0.7' fill='white' opacity='0.7'/%3E%3Ccircle cx='240' cy='580' r='0.5' fill='white' opacity='0.5'/%3E%3Ccircle cx='365' cy='545' r='0.8' fill='white' opacity='0.6'/%3E%3Ccircle cx='480' cy='570' r='0.6' fill='white' opacity='0.7'/%3E%3Ccircle cx='570' cy='510' r='0.9' fill='white' opacity='0.5'/%3E%3Ccircle cx='170' cy='430' r='0.7' fill='white' opacity='0.6'/%3E%3Ccircle cx='300' cy='330' r='0.5' fill='white' opacity='0.5'/%3E%3Ccircle cx='450' cy='290' r='0.8' fill='white' opacity='0.7'/%3E%3Ccircle cx='130' cy='330' r='0.6' fill='white' opacity='0.6'/%3E%3Ccircle cx='490' cy='450' r='0.7' fill='white' opacity='0.5'/%3E%3Ccircle cx='60' cy='90' r='0.5' fill='white' opacity='0.8'/%3E%3C/svg%3E");
  background-attachment: fixed, fixed, fixed, fixed, scroll;
  background-size: 100% 100%, 100% 100%, 100% 100%, 100% 100%, 600px 600px;
  background-repeat: no-repeat, no-repeat, no-repeat, no-repeat, repeat;
  color: var(--clr-text);
  line-height: 1.7;
  font-size: 1rem;
}

a { color: inherit; text-decoration: none; }
ul { list-style: none; }
img { display: block; max-width: 100%; }

/* =====================
   Utilities
   ===================== */
.container {
  max-width: var(--max-w);
  margin-inline: auto;
  padding-inline: 1.5rem;
}

.container--narrow { max-width: 720px; }

.section { padding-block: 6rem; }

.section--alt { background: rgba(13, 26, 45, 0.45); }

.section__title {
  font-size: clamp(1.8rem, 4vw, 2.4rem);
  font-weight: 700;
  margin-bottom: 3rem;
  text-align: center;
  position: relative;
}

.section__title::after {
  content: '';
  display: block;
  width: 48px;
  height: 3px;
  background: var(--clr-accent);
  border-radius: 2px;
  margin: 0.6rem auto 0;
}

.section__sub {
  text-align: center;
  color: var(--clr-muted);
  margin-bottom: 2.5rem;
  font-size: 1.05rem;
}

.subsection__title {
  font-size: 1.1rem;
  font-weight: 700;
  color: var(--clr-accent);
  margin-top: 3rem;
  margin-bottom: 1.25rem;
  padding-bottom: 0.5rem;
  border-bottom: 1px solid var(--clr-border);
}

/* =====================
   Buttons
   ===================== */
.btn {
  display: inline-block;
  padding: 0.75rem 1.75rem;
  border-radius: 8px;
  font-size: 0.95rem;
  font-weight: 600;
  cursor: pointer;
  border: none;
  transition: transform var(--transition), box-shadow var(--transition), background var(--transition);
}

.btn--primary {
  background: var(--clr-accent);
  color: #fff;
}

.btn--primary:hover {
  background: var(--clr-accent-light);
  transform: translateY(-2px);
  box-shadow: 0 6px 24px rgba(14, 165, 197, 0.35);
}

.btn--outline {
  background: transparent;
  color: var(--clr-accent);
  border: 2px solid var(--clr-accent);
}

.btn--outline:hover {
  background: var(--clr-accent);
  color: #fff;
  transform: translateY(-2px);
}

.btn--full { width: 100%; text-align: center; }

/* =====================
   Navigation
   ===================== */
.nav {
  position: fixed;
  top: 0; left: 0; right: 0;
  z-index: 100;
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 1rem 2rem;
  background: rgba(6, 14, 26, 0.9);
  backdrop-filter: blur(14px);
  border-bottom: 1px solid var(--clr-border);
}

.nav__logo {
  font-size: 1.15rem;
  font-weight: 800;
  color: var(--clr-accent);
  letter-spacing: 1px;
}

.nav__links {
  display: flex;
  gap: 2rem;
}

.nav__links a {
  color: var(--clr-muted);
  font-size: 0.875rem;
  font-weight: 500;
  transition: color var(--transition);
}

.nav__links a:hover { color: var(--clr-text); }

.nav__toggle {
  display: none;
  background: none;
  border: none;
  color: var(--clr-text);
  font-size: 1.4rem;
  cursor: pointer;
}

/* =====================
   Hero
   ===================== */
.hero {
  min-height: 100vh;
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 4rem;
  padding: 8rem 2rem 4rem;
  max-width: var(--max-w);
  margin-inline: auto;
}

.hero__content { max-width: 560px; }

.hero__avatar { flex-shrink: 0; }

.hero__greeting {
  color: var(--clr-muted);
  font-size: 0.9rem;
  font-weight: 600;
  letter-spacing: 1.5px;
  text-transform: uppercase;
  margin-bottom: 0.5rem;
}

.hero__name {
  font-size: clamp(2.2rem, 6vw, 3.8rem);
  font-weight: 800;
  line-height: 1.1;
  letter-spacing: -1px;
  background: linear-gradient(135deg, #e2eaf4 40%, var(--clr-accent-light));
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
}

.hero__role {
  font-size: 1.1rem;
  color: var(--clr-accent);
  font-weight: 600;
  margin-top: 0.6rem;
}

.hero__desc {
  color: var(--clr-muted);
  margin-top: 1rem;
  font-size: 1rem;
  max-width: 480px;
}

.hero__cta {
  display: flex;
  gap: 1rem;
  margin-top: 2rem;
  flex-wrap: wrap;
}

.avatar-placeholder {
  width: 260px;
  height: 260px;
  border-radius: 50%;
  background: linear-gradient(135deg, var(--clr-surface-2), var(--clr-border));
  border: 3px solid var(--clr-accent);
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 3.5rem;
  font-weight: 800;
  color: var(--clr-accent);
  flex-shrink: 0;
  box-shadow: 0 0 60px rgba(14, 165, 197, 0.15);
  letter-spacing: 1px;
}

.avatar-photo {
  display: block;
  width: 260px;
  height: 260px;
  max-width: 260px;
  border-radius: 50%;
  object-fit: cover;
  object-position: center top;
  border: 3px solid var(--clr-accent);
  flex-shrink: 0;
  box-shadow: 0 0 60px rgba(14, 165, 197, 0.15);
}

/* =====================
   About
   ===================== */
.about__grid {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 4rem;
  align-items: center;
}

.about__text p {
  color: var(--clr-muted);
  margin-bottom: 1rem;
}

.about__stats {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 1.25rem;
}

.stat {
  background: rgba(13, 26, 45, 0.5);
  backdrop-filter: blur(12px);
  -webkit-backdrop-filter: blur(12px);
  border: 1px solid rgba(56, 189, 248, 0.1);
  box-shadow: 0 4px 24px rgba(0, 0, 0, 0.3), inset 0 1px 0 rgba(255, 255, 255, 0.04);
  border-radius: var(--radius);
  padding: 1.5rem;
  text-align: center;
}

.stat__number {
  display: block;
  font-size: 2rem;
  font-weight: 800;
  color: var(--clr-accent);
  line-height: 1;
}

.stat__label {
  display: block;
  font-size: 0.78rem;
  color: var(--clr-muted);
  margin-top: 0.4rem;
  line-height: 1.3;
}

/* =====================
   Philosophy
   ===================== */
.philosophy__grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(300px, 1fr));
  gap: 1.5rem;
}

.philosophy__card {
  background: rgba(6, 14, 26, 0.45);
  backdrop-filter: blur(12px);
  -webkit-backdrop-filter: blur(12px);
  border: 1px solid rgba(56, 189, 248, 0.1);
  box-shadow: 0 4px 24px rgba(0, 0, 0, 0.3), inset 0 1px 0 rgba(255, 255, 255, 0.04);
  border-radius: var(--radius);
  padding: 1.75rem;
  transition: border-color var(--transition), transform var(--transition), box-shadow var(--transition);
}

.philosophy__card:hover {
  border-color: rgba(14, 165, 197, 0.4);
  box-shadow: 0 8px 32px rgba(14, 165, 197, 0.12), inset 0 1px 0 rgba(255, 255, 255, 0.04);
  transform: translateY(-3px);
}

.philosophy__icon {
  font-size: 1.25rem;
  color: var(--clr-accent);
  margin-bottom: 0.75rem;
}

.philosophy__card h3 {
  font-size: 1rem;
  font-weight: 700;
  margin-bottom: 0.6rem;
}

.philosophy__card p {
  color: var(--clr-muted);
  font-size: 0.92rem;
  line-height: 1.65;
}

/* =====================
   Timeline (Experience)
   ===================== */
.timeline { display: flex; flex-direction: column; gap: 3rem; }

.timeline__group-title {
  font-size: 0.8rem;
  font-weight: 700;
  text-transform: uppercase;
  letter-spacing: 1.5px;
  color: var(--clr-accent);
  margin-bottom: 1.5rem;
}

.timeline__item {
  display: flex;
  gap: 1.25rem;
  position: relative;
  padding-bottom: 1.75rem;
}

.timeline__item:not(:last-child)::after {
  content: '';
  position: absolute;
  left: 7px;
  top: 16px;
  bottom: 0;
  width: 2px;
  background: var(--clr-border);
}

.timeline__dot {
  width: 16px;
  height: 16px;
  border-radius: 50%;
  background: var(--clr-accent);
  border: 3px solid var(--clr-bg);
  flex-shrink: 0;
  margin-top: 4px;
  position: relative;
  z-index: 1;
}

.section--alt .timeline__dot {
  border-color: var(--clr-surface);
}

.timeline__body { flex: 1; }

.timeline__date {
  display: inline-block;
  font-size: 0.8rem;
  font-weight: 600;
  color: var(--clr-accent);
  background: var(--clr-accent-dim);
  padding: 0.2rem 0.6rem;
  border-radius: 4px;
  margin-bottom: 0.4rem;
}

.timeline__title {
  font-size: 1rem;
  font-weight: 700;
  margin-bottom: 0.2rem;
}

.timeline__org {
  color: var(--clr-muted);
  font-size: 0.9rem;
  margin-bottom: 0.6rem;
}

.timeline__bullets {
  list-style: disc;
  padding-left: 1.25rem;
  margin-top: 0.5rem;
}

.timeline__bullets li {
  color: var(--clr-muted);
  font-size: 0.88rem;
  margin-bottom: 0.25rem;
}

/* =====================
   Certifications
   ===================== */
.cert-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(280px, 1fr));
  gap: 1.25rem;
}

.cert-card--board {
  background: rgba(13, 26, 45, 0.5);
  backdrop-filter: blur(12px);
  -webkit-backdrop-filter: blur(12px);
  border: 1px solid rgba(14, 165, 197, 0.3);
  box-shadow: 0 4px 24px rgba(0, 0, 0, 0.3), inset 0 1px 0 rgba(255, 255, 255, 0.04);
  border-radius: var(--radius);
  padding: 1.75rem;
  display: flex;
  flex-direction: column;
  gap: 0.4rem;
}

.cert-card__icon {
  color: var(--clr-accent);
  font-size: 1.1rem;
}

.cert-card__title {
  font-size: 1rem;
  font-weight: 700;
}

.cert-card__sub {
  color: var(--clr-muted);
  font-size: 0.9rem;
}

.cert-card__date {
  color: var(--clr-accent);
  font-size: 0.8rem;
  font-weight: 600;
  margin-top: 0.25rem;
}

/* License badges */
.license-grid {
  display: flex;
  flex-wrap: wrap;
  gap: 0.75rem;
}

.license-badge {
  background: rgba(13, 26, 45, 0.5);
  backdrop-filter: blur(8px);
  -webkit-backdrop-filter: blur(8px);
  border: 1px solid rgba(56, 189, 248, 0.1);
  border-radius: 6px;
  padding: 0.4rem 1rem;
  font-size: 0.85rem;
  font-weight: 600;
  color: var(--clr-text);
}

/* Epic badges */
.cert-grid--epic {
  grid-template-columns: repeat(auto-fill, minmax(200px, 1fr));
  gap: 0.75rem;
}

.epic-badge {
  background: rgba(13, 26, 45, 0.5);
  backdrop-filter: blur(8px);
  -webkit-backdrop-filter: blur(8px);
  border: 1px solid rgba(56, 189, 248, 0.1);
  border-radius: 8px;
  padding: 0.75rem 1rem;
  font-size: 0.85rem;
  font-weight: 600;
  display: flex;
  flex-direction: column;
  gap: 0.2rem;
}

.epic-badge span {
  color: var(--clr-accent);
  font-size: 0.78rem;
  font-weight: 700;
}

/* =====================
   Skills
   ===================== */
.skills__grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(240px, 1fr));
  gap: 1.5rem;
}

.skill-group {
  background: rgba(13, 26, 45, 0.5);
  backdrop-filter: blur(12px);
  -webkit-backdrop-filter: blur(12px);
  border: 1px solid rgba(56, 189, 248, 0.1);
  box-shadow: 0 4px 24px rgba(0, 0, 0, 0.3), inset 0 1px 0 rgba(255, 255, 255, 0.04);
  border-radius: var(--radius);
  padding: 1.5rem;
}

.skill-group__title {
  font-size: 0.9rem;
  font-weight: 700;
  color: var(--clr-accent);
  margin-bottom: 0.85rem;
  padding-bottom: 0.6rem;
  border-bottom: 1px solid var(--clr-border);
}

.skill-list li {
  color: var(--clr-muted);
  font-size: 0.9rem;
  padding: 0.3rem 0;
}

.skill-list li:not(:last-child) {
  border-bottom: 1px solid var(--clr-border);
}

/* =====================
   Education
   ===================== */
.edu-list {
  display: flex;
  flex-direction: column;
  gap: 0;
  border-left: 2px solid var(--clr-border);
  margin-left: 0.5rem;
}

.edu-item {
  display: flex;
  gap: 1.5rem;
  padding: 1.25rem 0 1.25rem 1.75rem;
  position: relative;
}

.edu-item::before {
  content: '';
  position: absolute;
  left: -5px;
  top: 1.6rem;
  width: 8px;
  height: 8px;
  border-radius: 50%;
  background: var(--clr-accent);
}

.edu-item__year {
  font-size: 0.78rem;
  font-weight: 700;
  color: var(--clr-accent);
  white-space: nowrap;
  min-width: 80px;
  padding-top: 0.1rem;
}

.edu-item strong {
  display: block;
  font-size: 0.95rem;
  font-weight: 700;
  margin-bottom: 0.15rem;
}

.edu-item p {
  color: var(--clr-muted);
  font-size: 0.875rem;
}

/* =====================
   Publications
   ===================== */
.pub-list {
  display: flex;
  flex-direction: column;
  gap: 1rem;
}

.pub-item {
  display: flex;
  gap: 1rem;
  align-items: flex-start;
  background: rgba(13, 26, 45, 0.5);
  backdrop-filter: blur(12px);
  -webkit-backdrop-filter: blur(12px);
  border: 1px solid rgba(56, 189, 248, 0.1);
  box-shadow: 0 4px 24px rgba(0, 0, 0, 0.3), inset 0 1px 0 rgba(255, 255, 255, 0.04);
  border-radius: var(--radius);
  padding: 1.25rem;
  transition: border-color var(--transition), box-shadow var(--transition);
}

.pub-item:hover {
  border-color: rgba(14, 165, 197, 0.35);
  box-shadow: 0 6px 28px rgba(14, 165, 197, 0.1), inset 0 1px 0 rgba(255, 255, 255, 0.04);
}

.pub-item__type {
  font-size: 0.7rem;
  font-weight: 700;
  text-transform: uppercase;
  letter-spacing: 0.8px;
  white-space: nowrap;
  padding: 0.3rem 0.6rem;
  border-radius: 4px;
  flex-shrink: 0;
  margin-top: 0.1rem;
}

.pub-item__type--journal {
  background: rgba(14, 165, 197, 0.15);
  color: var(--clr-accent);
}

.pub-item__type--book {
  background: rgba(99, 179, 100, 0.15);
  color: #6bb36a;
}

.pub-item__type--oral {
  background: rgba(251, 191, 36, 0.15);
  color: #f5b93e;
}

.pub-item__citation {
  color: var(--clr-muted);
  font-size: 0.9rem;
  line-height: 1.6;
}

.pub-item__citation em {
  color: var(--clr-text);
  font-style: italic;
}

/* =====================
   Contact Form
   ===================== */
.form__row {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 1rem;
}

.form__group {
  display: flex;
  flex-direction: column;
  margin-bottom: 1.25rem;
}

.form__group label {
  font-size: 0.83rem;
  font-weight: 600;
  color: var(--clr-muted);
  margin-bottom: 0.4rem;
}

.form__group input,
.form__group textarea {
  background: rgba(6, 14, 26, 0.55);
  backdrop-filter: blur(8px);
  -webkit-backdrop-filter: blur(8px);
  border: 1px solid rgba(56, 189, 248, 0.1);
  border-radius: 8px;
  padding: 0.75rem 1rem;
  color: var(--clr-text);
  font-size: 0.95rem;
  font-family: inherit;
  transition: border-color var(--transition);
  resize: vertical;
}

.form__group input:focus,
.form__group textarea:focus {
  outline: none;
  border-color: var(--clr-accent);
}

.form__group input::placeholder,
.form__group textarea::placeholder { color: var(--clr-border); }

/* =====================
   Footer
   ===================== */
.footer {
  padding: 2rem 1.5rem;
  border-top: 1px solid var(--clr-border);
}

.footer .container {
  display: flex;
  align-items: center;
  justify-content: space-between;
  flex-wrap: wrap;
  gap: 1rem;
}

.footer__copy { color: var(--clr-muted); font-size: 0.83rem; }

.footer__social a {
  color: var(--clr-accent);
  font-size: 0.83rem;
  font-weight: 700;
  transition: color var(--transition);
}

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

/* =====================
   Responsive
   ===================== */
@media (max-width: 768px) {
  .nav__links { display: none; }
  .nav__links.open {
    display: flex;
    flex-direction: column;
    position: absolute;
    top: 100%;
    left: 0; right: 0;
    background: rgba(6, 14, 26, 0.85);
    backdrop-filter: blur(16px);
    -webkit-backdrop-filter: blur(16px);
    padding: 1.5rem 2rem;
    border-bottom: 1px solid rgba(56, 189, 248, 0.1);
    gap: 1.25rem;
  }
  .nav__toggle { display: block; }

  .hero {
    flex-direction: column-reverse;
    text-align: center;
    padding-top: 7rem;
    gap: 2rem;
  }
  .hero__cta { justify-content: center; }
  .avatar-placeholder { width: 180px; height: 180px; font-size: 2.2rem; }
  .avatar-photo { width: 180px; height: 180px; }

  .about__grid { grid-template-columns: 1fr; gap: 2rem; }
  .form__row { grid-template-columns: 1fr; }
  .pub-item { flex-direction: column; gap: 0.5rem; }

  .footer .container { flex-direction: column; text-align: center; }
}