/* ============================================
   DESIGN SYSTEM — Thodoris Tsilivis Academic Site
   Solarized Light theme with teal accents
   ============================================ */

/* ---------- Google Fonts ---------- */
@import url('https://fonts.googleapis.com/css2?family=Inter:wght@300;400;500;600;700&family=JetBrains+Mono:wght@400;500&display=swap');

/* ---------- Custom Properties ---------- */
:root {
  /* Colors — Solarized Light inspired */
  --bg-primary: #fdf6e3;
  --bg-secondary: #eee8d5;
  --bg-card: #ffffff;
  --bg-card-hover: #f5efdc;
  --bg-hero: linear-gradient(135deg, #fdf6e3 0%, #eee8d5 40%, #e8e1cc 100%);

  --text-primary: #073642;
  --text-secondary: #586e75;
  --text-muted: #93a1a1;

  --accent: #2aa198;
  --accent-hover: #1a847d;
  --accent-dim: rgba(42, 161, 152, 0.1);
  --accent-glow: rgba(42, 161, 152, 0.25);

  --border: rgba(0, 0, 0, 0.08);
  --border-accent: rgba(42, 161, 152, 0.3);

  /* Typography */
  --font-body: 'Inter', -apple-system, BlinkMacSystemFont, sans-serif;
  --font-mono: 'JetBrains Mono', 'Fira Code', monospace;

  /* Sizing */
  --max-width: 1100px;
  --nav-height: 64px;
  --section-padding: 100px 0;
  --border-radius: 12px;
  --border-radius-sm: 8px;

  /* Transitions */
  --transition-fast: 0.2s cubic-bezier(0.4, 0, 0.2, 1);
  --transition-medium: 0.4s cubic-bezier(0.4, 0, 0.2, 1);
  --transition-slow: 0.6s cubic-bezier(0.4, 0, 0.2, 1);
}

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

html {
  scroll-behavior: smooth;
  scroll-padding-top: var(--nav-height);
  font-size: 16px;
}

body {
  font-family: var(--font-body);
  background-color: var(--bg-primary);
  color: var(--text-primary);
  line-height: 1.7;
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
  overflow-x: hidden;
}

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

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

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

::selection {
  background: rgba(42, 161, 152, 0.2);
  color: #073642;
}

/* ---------- Navigation ---------- */
.nav {
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  height: var(--nav-height);
  background: rgba(253, 246, 227, 0.9);
  backdrop-filter: blur(20px);
  -webkit-backdrop-filter: blur(20px);
  border-bottom: 1px solid var(--border);
  z-index: 1000;
  transition: background var(--transition-medium);
}

.nav.scrolled {
  background: rgba(253, 246, 227, 0.97);
  border-bottom-color: var(--border-accent);
}

.nav__inner {
  max-width: var(--max-width);
  margin: 0 auto;
  padding: 0 2rem;
  height: 100%;
  display: flex;
  align-items: center;
  justify-content: space-between;
}

.nav__brand {
  font-size: 1.15rem;
  font-weight: 600;
  color: var(--text-primary);
  letter-spacing: -0.02em;
}

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

.nav__links {
  display: flex;
  gap: 0.25rem;
  list-style: none;
}

.nav__links a {
  color: var(--text-secondary);
  font-size: 0.875rem;
  font-weight: 500;
  padding: 0.5rem 1rem;
  border-radius: 8px;
  transition: all var(--transition-fast);
  position: relative;
}

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

/* Hamburger */
.nav__hamburger {
  display: none;
  flex-direction: column;
  gap: 5px;
  background: none;
  border: none;
  cursor: pointer;
  padding: 4px;
  z-index: 1001;
}

.nav__hamburger span {
  width: 24px;
  height: 2px;
  background: var(--text-primary);
  border-radius: 2px;
  transition: all var(--transition-fast);
}

.nav__hamburger.open span:nth-child(1) {
  transform: rotate(45deg) translate(5px, 5px);
}

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

.nav__hamburger.open span:nth-child(3) {
  transform: rotate(-45deg) translate(5px, -5px);
}

/* ---------- Hero Section ---------- */
.hero {
  min-height: 100vh;
  display: flex;
  align-items: center;
  justify-content: center;
  background: var(--bg-hero);
  position: relative;
  overflow: hidden;
  padding: 0 2rem;
}

.hero__canvas {
  position: absolute;
  inset: 0;
  opacity: 0.4;
}

.hero__content {
  position: relative;
  z-index: 2;
  text-align: center;
  max-width: 700px;
}

.hero__greeting {
  font-family: var(--font-mono);
  font-size: 0.9rem;
  color: var(--accent);
  margin-bottom: 1rem;
  opacity: 0;
  animation: fadeInUp 0.6s 0.3s forwards;
}

.hero__name {
  font-size: clamp(2.5rem, 6vw, 4rem);
  font-weight: 700;
  letter-spacing: -0.03em;
  line-height: 1.1;
  margin-bottom: 1.25rem;
  opacity: 0;
  animation: fadeInUp 0.6s 0.5s forwards;
}

.hero__name .accent {
  background: linear-gradient(135deg, var(--accent), #268bd2);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
}

.hero__subtitle {
  font-size: 1.15rem;
  color: var(--text-secondary);
  font-weight: 400;
  line-height: 1.6;
  margin-bottom: 2rem;
  opacity: 0;
  animation: fadeInUp 0.6s 0.7s forwards;
}

.hero__cta-group {
  display: flex;
  gap: 1rem;
  justify-content: center;
  flex-wrap: wrap;
  opacity: 0;
  animation: fadeInUp 0.6s 0.9s forwards;
}

.btn {
  display: inline-flex;
  align-items: center;
  gap: 0.5rem;
  padding: 0.75rem 1.75rem;
  border-radius: 50px;
  font-size: 0.9rem;
  font-weight: 500;
  font-family: var(--font-body);
  cursor: pointer;
  transition: all var(--transition-fast);
  border: none;
}

.btn--primary {
  background: var(--accent);
  color: var(--bg-primary);
}

.btn--primary:hover {
  background: var(--accent-hover);
  color: var(--bg-primary);
  transform: translateY(-2px);
  box-shadow: 0 8px 30px var(--accent-glow);
}

.btn--outline {
  background: transparent;
  color: var(--accent);
  border: 1.5px solid var(--border-accent);
}

.btn--outline:hover {
  background: var(--accent-dim);
  border-color: var(--accent);
  color: var(--accent-hover);
  transform: translateY(-2px);
}

.hero__scroll-hint {
  position: absolute;
  bottom: 2rem;
  left: 50%;
  transform: translateX(-50%);
  color: var(--text-muted);
  font-size: 0.8rem;
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 0.5rem;
  animation: bounce 2s infinite;
}

.hero__scroll-hint svg {
  width: 20px;
  height: 20px;
  stroke: var(--text-muted);
}

/* ---------- Section Base ---------- */
.section {
  padding: var(--section-padding);
  position: relative;
}

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

.container {
  max-width: var(--max-width);
  margin: 0 auto;
  padding: 0 2rem;
}

.section__header {
  margin-bottom: 3.5rem;
}

.section__label {
  font-family: var(--font-mono);
  font-size: 0.8rem;
  color: var(--accent);
  text-transform: uppercase;
  letter-spacing: 0.15em;
  margin-bottom: 0.75rem;
  display: block;
}

.section__title {
  font-size: clamp(1.75rem, 4vw, 2.5rem);
  font-weight: 700;
  letter-spacing: -0.02em;
  line-height: 1.2;
}

.section__divider {
  width: 60px;
  height: 3px;
  background: linear-gradient(90deg, var(--accent), transparent);
  border-radius: 2px;
  margin-top: 1rem;
}

/* ---------- About Section ---------- */
.about__grid {
  display: grid;
  grid-template-columns: 280px 1fr;
  gap: 4rem;
  align-items: start;
}

.about__photo-wrapper {
  position: relative;
}

.about__photo {
  width: 280px;
  height: 340px;
  object-fit: cover;
  object-position: 39% 50%;
  border-radius: var(--border-radius);
  border: 2px solid var(--border-accent);
  position: relative;
  z-index: 2;
}

.about__photo-wrapper::before {
  content: '';
  position: absolute;
  inset: 8px -8px -8px 8px;
  border: 2px solid var(--accent-dim);
  border-radius: var(--border-radius);
  z-index: 1;
}

.about__bio p {
  color: var(--text-secondary);
  margin-bottom: 1.25rem;
  font-size: 1.02rem;
}

.about__bio strong {
  color: var(--text-primary);
  font-weight: 600;
}

.about__details {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 1rem;
  margin-top: 2rem;
}

.about__detail {
  display: flex;
  align-items: center;
  gap: 0.75rem;
  padding: 0.75rem 1rem;
  background: var(--bg-card);
  border-radius: var(--border-radius-sm);
  border: 1px solid var(--border);
  transition: border-color var(--transition-fast);
}

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

.about__detail-icon {
  font-size: 1.2rem;
  flex-shrink: 0;
}

.about__detail-content {
  display: flex;
  flex-direction: column;
}

.about__detail-label {
  font-size: 0.7rem;
  color: var(--text-muted);
  text-transform: uppercase;
  letter-spacing: 0.08em;
}

.about__detail-value {
  font-size: 0.9rem;
  color: var(--text-primary);
  font-weight: 500;
}

/* ---------- Research Section ---------- */
.research__category {
  margin-bottom: 3rem;
}

.research__category:last-child {
  margin-bottom: 0;
}

.research__category-title {
  font-size: 1.1rem;
  font-weight: 600;
  color: var(--text-primary);
  margin-bottom: 1.25rem;
  display: flex;
  align-items: center;
  gap: 0.75rem;
}

.research__category-title::before {
  content: '';
  width: 8px;
  height: 8px;
  background: var(--accent);
  border-radius: 50%;
  flex-shrink: 0;
}

.research__category-title .badge {
  font-size: 0.7rem;
  font-weight: 500;
  padding: 0.2rem 0.65rem;
  border-radius: 50px;
  background: var(--accent-dim);
  color: var(--accent);
  font-family: var(--font-mono);
}

.paper-card {
  background: var(--bg-card);
  border: 1px solid var(--border);
  border-radius: var(--border-radius);
  padding: 1.5rem;
  margin-bottom: 1rem;
  transition: all var(--transition-medium);
  position: relative;
  overflow: hidden;
}

.paper-card::before {
  content: '';
  position: absolute;
  left: 0;
  top: 0;
  bottom: 0;
  width: 3px;
  background: var(--accent);
  opacity: 0;
  transition: opacity var(--transition-fast);
}

.paper-card:hover {
  border-color: var(--border-accent);
  background: var(--bg-card-hover);
  transform: translateX(4px);
}

.paper-card:hover::before {
  opacity: 1;
}

.paper-card__title {
  font-size: 1.05rem;
  font-weight: 600;
  color: var(--text-primary);
  margin-bottom: 0.5rem;
  line-height: 1.4;
}

.paper-card__authors {
  font-size: 0.88rem;
  color: var(--text-secondary);
  margin-bottom: 0.75rem;
}

.paper-card__meta {
  display: flex;
  align-items: center;
  gap: 1rem;
  flex-wrap: wrap;
}

.paper-card__venue {
  font-size: 0.8rem;
  font-family: var(--font-mono);
  color: var(--accent);
  padding: 0.2rem 0.6rem;
  background: var(--accent-dim);
  border-radius: 4px;
}

.paper-card__link {
  font-size: 0.85rem;
  font-weight: 500;
  display: inline-flex;
  align-items: center;
  gap: 0.3rem;
}

.paper-card__link svg {
  width: 14px;
  height: 14px;
}

/* ---------- Teaching Section ---------- */
.teaching__list {
  display: grid;
  gap: 1rem;
}

.teaching-card {
  display: flex;
  align-items: center;
  gap: 1.5rem;
  padding: 1.25rem 1.5rem;
  background: var(--bg-card);
  border: 1px solid var(--border);
  border-radius: var(--border-radius);
  transition: all var(--transition-medium);
}

.teaching-card:hover {
  border-color: var(--border-accent);
  background: var(--bg-card-hover);
}

.teaching-card__year {
  font-family: var(--font-mono);
  font-size: 0.85rem;
  color: var(--accent);
  white-space: nowrap;
  min-width: 90px;
}

.teaching-card__divider {
  width: 1px;
  height: 40px;
  background: var(--border);
  flex-shrink: 0;
}

.teaching-card__info {
  flex: 1;
}

.teaching-card__name {
  font-weight: 600;
  font-size: 0.95rem;
  color: var(--text-primary);
  margin-bottom: 0.2rem;
}

.teaching-card__role {
  font-size: 0.82rem;
  color: var(--text-secondary);
}

/* ---------- Presentations Section ---------- */
.presentations__year-group {
  margin-bottom: 2.5rem;
}

.presentations__year-group:last-child {
  margin-bottom: 0;
}

.presentations__year {
  font-family: var(--font-mono);
  font-size: 1.5rem;
  font-weight: 700;
  color: var(--accent);
  margin-bottom: 1rem;
  opacity: 0.6;
}

.presentation-item {
  display: flex;
  align-items: flex-start;
  gap: 1rem;
  padding: 1rem 1.25rem;
  border-left: 2px solid var(--border);
  margin-left: 0.5rem;
  margin-bottom: 0.5rem;
  transition: all var(--transition-fast);
}

.presentation-item:hover {
  border-left-color: var(--accent);
  background: var(--bg-card);
  border-radius: 0 var(--border-radius-sm) var(--border-radius-sm) 0;
}

.presentation-item__content {
  flex: 1;
}

.presentation-item__title {
  font-weight: 500;
  font-size: 0.95rem;
  color: var(--text-primary);
  margin-bottom: 0.3rem;
}

.presentation-item__venue {
  font-size: 0.82rem;
  color: var(--text-secondary);
}

.presentation-item__links {
  display: flex;
  gap: 0.75rem;
  flex-shrink: 0;
}

.presentation-item__links a {
  font-size: 0.8rem;
  font-weight: 500;
  padding: 0.3rem 0.75rem;
  border-radius: 50px;
  border: 1px solid var(--border-accent);
  transition: all var(--transition-fast);
}

.presentation-item__links a:hover {
  background: var(--accent-dim);
}

/* ---------- Notes Section ---------- */
.notes-card {
  background: var(--bg-card);
  border: 1px solid var(--border);
  border-radius: var(--border-radius);
  padding: 1.5rem;
  transition: all var(--transition-medium);
  display: flex;
  align-items: center;
  gap: 1.25rem;
}

.notes-card:hover {
  border-color: var(--border-accent);
  background: var(--bg-card-hover);
}

.notes-card__icon {
  font-size: 2rem;
  flex-shrink: 0;
}

.notes-card__info {
  flex: 1;
}

.notes-card__title {
  font-weight: 600;
  font-size: 0.95rem;
  color: var(--text-primary);
  margin-bottom: 0.2rem;
}

.notes-card__detail {
  font-size: 0.82rem;
  color: var(--text-secondary);
}

/* ---------- Personal Section ---------- */
.personal__intro {
  color: var(--text-secondary);
  font-size: 1.02rem;
  margin-bottom: 2.5rem;
  max-width: 700px;
  line-height: 1.8;
}

.personal__gallery {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(250px, 1fr));
  gap: 1.25rem;
}

.gallery-card {
  border-radius: var(--border-radius);
  overflow: hidden;
  border: 1px solid var(--border);
  transition: all var(--transition-medium);
  background: var(--bg-card);
}

.gallery-card:hover {
  border-color: var(--border-accent);
  transform: translateY(-4px);
  box-shadow: 0 12px 40px rgba(0, 0, 0, 0.08);
}

.gallery-card__image {
  width: 100%;
  height: 200px;
  object-fit: cover;
  transition: transform var(--transition-slow);
  cursor: pointer;
}

.gallery-card:hover .gallery-card__image {
  transform: scale(1.05);
}

.gallery-card__caption {
  padding: 0.85rem 1rem;
  font-size: 0.85rem;
  font-weight: 500;
  color: var(--text-secondary);
  text-align: center;
}

/* ---------- Footer ---------- */
.footer {
  padding: 3rem 0;
  background: var(--bg-secondary);
  border-top: 1px solid var(--border);
  text-align: center;
}

.footer__links {
  display: flex;
  justify-content: center;
  gap: 1.5rem;
  margin-bottom: 1.5rem;
  flex-wrap: wrap;
}

.footer__links a {
  color: var(--text-secondary);
  font-size: 0.88rem;
  font-weight: 500;
  transition: color var(--transition-fast);
}

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

.footer__copy {
  color: var(--text-muted);
  font-size: 0.78rem;
}

/* ---------- Image Modal ---------- */
.modal {
  display: none;
  position: fixed;
  z-index: 2000;
  left: 0;
  top: 0;
  width: 100%;
  height: 100%;
  background-color: rgba(0, 0, 0, 0.9);
  backdrop-filter: blur(5px);
  -webkit-backdrop-filter: blur(5px);
  justify-content: center;
  align-items: center;
  flex-direction: column;
}

.modal.show {
  display: flex;
}

.modal__content {
  max-width: 90%;
  max-height: 80vh;
  border-radius: var(--border-radius);
  box-shadow: 0 10px 30px rgba(0, 0, 0, 0.5);
  animation: zoomIn 0.3s ease;
  object-fit: contain;
}

.modal__caption {
  margin-top: 15px;
  width: 80%;
  max-width: 700px;
  text-align: center;
  color: var(--bg-primary);
  font-size: 1rem;
  font-weight: 500;
  animation: zoomIn 0.3s ease;
}

@keyframes zoomIn {
  from {
    transform: scale(0.9);
    opacity: 0;
  }

  to {
    transform: scale(1);
    opacity: 1;
  }
}

.modal__close {
  position: absolute;
  top: 30px;
  right: 40px;
  color: #f1f1f1;
  font-size: 40px;
  font-weight: bold;
  transition: color var(--transition-fast);
  cursor: pointer;
  z-index: 2001;
}

.modal__close:hover,
.modal__close:focus {
  color: var(--accent);
  text-decoration: none;
}

/* ---------- Scroll Reveal (JS-driven) ---------- */
.reveal {
  opacity: 0;
  transform: translateY(30px);
  transition: opacity var(--transition-slow), transform var(--transition-slow);
}

.reveal.visible {
  opacity: 1;
  transform: translateY(0);
}

/* ---------- Keyframe Animations ---------- */
@keyframes fadeInUp {
  from {
    opacity: 0;
    transform: translateY(20px);
  }

  to {
    opacity: 1;
    transform: translateY(0);
  }
}

@keyframes bounce {

  0%,
  20%,
  50%,
  80%,
  100% {
    transform: translateX(-50%) translateY(0);
  }

  40% {
    transform: translateX(-50%) translateY(-8px);
  }

  60% {
    transform: translateX(-50%) translateY(-4px);
  }
}

@keyframes pulse {

  0%,
  100% {
    opacity: 0.4;
  }

  50% {
    opacity: 0.8;
  }
}

/* ---------- Responsive ---------- */
@media (max-width: 768px) {
  :root {
    --section-padding: 60px 0;
  }

  .nav__links {
    position: fixed;
    top: 0;
    right: -100%;
    width: 280px;
    height: 100vh;
    background: var(--bg-secondary);
    flex-direction: column;
    padding: 5rem 2rem 2rem;
    gap: 0.5rem;
    border-left: 1px solid var(--border);
    transition: right var(--transition-medium);
  }

  .nav__links.open {
    right: 0;
  }

  .nav__links a {
    font-size: 1rem;
    padding: 0.75rem 1rem;
  }

  .nav__hamburger {
    display: flex;
  }

  .hero__content {
    padding-top: 2rem;
  }

  .about__grid {
    grid-template-columns: 1fr;
    gap: 2rem;
    text-align: center;
  }

  .about__photo-wrapper {
    margin: 0 auto;
  }

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

  .teaching-card {
    flex-direction: column;
    align-items: flex-start;
    gap: 0.75rem;
  }

  .teaching-card__divider {
    width: 100%;
    height: 1px;
  }

  .presentation-item {
    flex-direction: column;
    gap: 0.75rem;
  }

  .personal__gallery {
    grid-template-columns: repeat(auto-fill, minmax(200px, 1fr));
  }

  .hero__cta-group {
    flex-direction: column;
    align-items: center;
  }
}

@media (max-width: 480px) {
  .hero__name {
    font-size: 2rem;
  }

  .section__title {
    font-size: 1.5rem;
  }

  .about__photo {
    width: 200px;
    height: 250px;
  }
}