/* ============================================
   Design System — Dr. Yifat Aran
   ============================================ */

:root {
  --color-bg: #FAFAF8;
  --color-text: #1B2838;
  --color-accent: #1B2838;
  --color-accent-hover: #0F1C2E;
  --color-accent-light: #F0F1F3;
  --color-link: #1B2838;
  --color-link-hover: #0F1C2E;
  --color-muted: #7C8794;
  --color-border: #E2E0DC;
  --color-surface: #FFFFFF;
  --color-surface-hover: #F5F5F3;
  --color-badge-bg: #EEF0F2;
  --color-badge-text: #4A5568;
  --color-gold: #2B4C7E;
  --color-gold-light: #3D6098;

  --font-heading: 'Playfair Display', Georgia, 'Times New Roman', serif;
  --font-body: 'Inter', system-ui, -apple-system, sans-serif;

  --max-width: 780px;
  --nav-height: 64px;
  --section-gap: clamp(4rem, 8vw, 7rem);
}

/* Dark mode */
.dark-mode {
  --color-bg: #0D1117;
  --color-text: #E2E4E8;
  --color-accent: #E2E4E8;
  --color-accent-hover: #FFFFFF;
  --color-accent-light: #161B22;
  --color-link: #5B8DB8;
  --color-link-hover: #7CAAD0;
  --color-muted: #8B949E;
  --color-border: #21262D;
  --color-surface: #161B22;
  --color-surface-hover: #1C2128;
  --color-badge-bg: #1C2128;
  --color-badge-text: #8B949E;
  --color-gold: #5B8DB8;
  --color-gold-light: #2B4C7E;
}

/* ============================================
   Reset & Base
   ============================================ */

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

html {
  scroll-behavior: smooth;
  scroll-padding-top: calc(var(--nav-height) + 1rem);
}

body {
  font-family: var(--font-body);
  font-size: 1rem;
  line-height: 1.75;
  color: var(--color-text);
  background-color: var(--color-bg);
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
  transition: background-color 0.3s ease, color 0.3s ease;
}

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

a {
  color: var(--color-link);
  text-decoration: none;
  transition: color 0.2s ease;
}

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

ul {
  list-style: none;
}

/* ============================================
   Scroll Animations
   ============================================ */

.fade-in {
  opacity: 0;
  transform: translateY(20px);
  transition: opacity 0.7s ease, transform 0.7s ease;
}

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

.stagger > * {
  opacity: 0;
  transform: translateY(12px);
  transition: opacity 0.5s ease, transform 0.5s ease;
}

.stagger.visible > *:nth-child(1) { transition-delay: 0s; }
.stagger.visible > *:nth-child(2) { transition-delay: 0.1s; }
.stagger.visible > *:nth-child(3) { transition-delay: 0.2s; }
.stagger.visible > *:nth-child(4) { transition-delay: 0.3s; }
.stagger.visible > *:nth-child(5) { transition-delay: 0.4s; }
.stagger.visible > *:nth-child(6) { transition-delay: 0.5s; }
.stagger.visible > *:nth-child(7) { transition-delay: 0.6s; }
.stagger.visible > *:nth-child(8) { transition-delay: 0.7s; }
.stagger.visible > *:nth-child(9) { transition-delay: 0.8s; }
.stagger.visible > *:nth-child(10) { transition-delay: 0.9s; }

.stagger.visible > * {
  opacity: 1;
  transform: translateY(0);
}

/* ============================================
   Typography
   ============================================ */

h1, h2, h3 {
  font-family: var(--font-heading);
  font-weight: 400;
  line-height: 1.3;
}

h1 {
  font-size: clamp(2.25rem, 5vw, 3.25rem);
  letter-spacing: -0.02em;
  font-weight: 400;
}

h2 {
  font-size: clamp(1.35rem, 3vw, 1.65rem);
  margin-bottom: 2.5rem;
  letter-spacing: 0.04em;
  text-transform: uppercase;
  font-family: var(--font-body);
  font-weight: 300;
  color: var(--color-muted);
  position: relative;
  padding-bottom: 1rem;
}

h2::after {
  content: '';
  position: absolute;
  bottom: 0;
  left: 0;
  width: 32px;
  height: 1px;
  background: var(--color-gold);
}

h3 {
  font-size: 1.1rem;
  font-weight: 600;
  font-family: var(--font-body);
  color: var(--color-text);
  margin-bottom: 0.5rem;
}

p {
  margin-bottom: 1rem;
}

em {
  font-style: italic;
}

strong {
  font-weight: 600;
}

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

/* ============================================
   Layout
   ============================================ */

.container {
  max-width: var(--max-width);
  margin: 0 auto;
  padding: 0 1.5rem;
}

.section {
  padding: var(--section-gap) 0;
  position: relative;
}

.section + .section {
  border-top: 1px solid var(--color-border);
}

/* ============================================
   Navigation
   ============================================ */

.site-header {
  position: sticky;
  top: 0;
  z-index: 100;
  border-bottom: 1px solid var(--color-border);
  backdrop-filter: blur(20px) saturate(180%);
  -webkit-backdrop-filter: blur(20px) saturate(180%);
  background: color-mix(in srgb, var(--color-bg) 85%, transparent);
}

.nav {
  max-width: var(--max-width);
  margin: 0 auto;
  padding: 0 1.5rem;
  height: var(--nav-height);
  display: flex;
  align-items: center;
  justify-content: space-between;
}

.nav-logo {
  font-family: var(--font-heading);
  font-size: 1.1rem;
  font-weight: 400;
  color: var(--color-text);
  text-decoration: none;
  letter-spacing: 0.02em;
}

.nav-logo:hover {
  color: var(--color-gold);
}

.nav-links {
  display: flex;
  align-items: center;
  gap: 2rem;
}

.nav-links a {
  font-size: 0.8rem;
  font-weight: 400;
  color: var(--color-muted);
  text-decoration: none;
  letter-spacing: 0.06em;
  text-transform: uppercase;
  position: relative;
  transition: color 0.3s ease;
}

.nav-links a::after {
  content: '';
  position: absolute;
  bottom: -4px;
  left: 0;
  width: 0;
  height: 1px;
  background: var(--color-gold);
  transition: width 0.3s ease;
}

.nav-links a:hover,
.nav-links a.active {
  color: var(--color-text);
}

.nav-links a:hover::after,
.nav-links a.active::after {
  width: 100%;
}

.nav-toggle {
  display: none;
  background: none;
  border: none;
  cursor: pointer;
  padding: 0.5rem;
  flex-direction: column;
  gap: 5px;
}

.nav-toggle span {
  display: block;
  width: 20px;
  height: 1px;
  background: var(--color-text);
  transition: transform 0.3s ease, opacity 0.3s ease;
}

/* Theme toggle */
.theme-toggle {
  background: none;
  border: none;
  cursor: pointer;
  color: var(--color-muted);
  padding: 0.25rem;
  display: flex;
  align-items: center;
  transition: color 0.3s ease;
}

.theme-toggle:hover {
  color: var(--color-gold);
}

.icon-moon { display: none; }
.dark-mode .icon-sun { display: none; }
.dark-mode .icon-moon { display: block; }

/* ============================================
   Hero / About
   ============================================ */

.hero {
  padding-top: clamp(3rem, 6vw, 5rem);
}

.hero-grid {
  display: grid;
  grid-template-columns: 220px 1fr;
  gap: 3rem;
  align-items: start;
  margin-bottom: 3rem;
}

.hero-photo {
  position: relative;
}

.hero-photo img {
  width: 100%;
  border-radius: 2px;
  aspect-ratio: 4 / 5;
  object-fit: cover;
  filter: grayscale(15%);
  transition: filter 0.5s ease;
}

.hero-photo img:hover {
  filter: grayscale(0%);
}

.hero-text {
  padding-top: 0.75rem;
}

h1 .gradient-text {
  color: var(--color-text);
}

.hero-title {
  font-size: 0.85rem;
  color: var(--color-gold);
  font-weight: 400;
  letter-spacing: 0.08em;
  text-transform: uppercase;
  margin-bottom: 0.25rem;
}

.hero-tagline {
  font-family: var(--font-heading);
  font-size: 1.05rem;
  font-style: italic;
  font-weight: 400;
  color: var(--color-muted);
  margin-bottom: 1rem;
}

.cv-download {
  display: inline-flex;
  align-items: center;
  gap: 0.5rem;
  font-size: 0.8rem;
  font-weight: 500;
  letter-spacing: 0.06em;
  text-transform: uppercase;
  color: var(--color-gold);
  border: 1px solid var(--color-gold);
  padding: 0.5rem 1.25rem;
  border-radius: 2px;
  margin-top: 1.25rem;
  transition: background 0.2s ease, color 0.2s ease;
}

.cv-download:hover {
  background: var(--color-gold);
  color: var(--color-bg);
}

.hero-affiliations {
  font-size: 0.9rem;
  color: var(--color-muted);
  line-height: 2;
}

.hero-affiliations a {
  color: var(--color-muted);
  border-bottom: 1px solid var(--color-border);
  transition: color 0.2s ease, border-color 0.2s ease;
}

.hero-affiliations a:hover {
  color: var(--color-text);
  border-color: var(--color-gold);
}

.bio {
  margin-bottom: 3rem;
  font-size: 1.025rem;
}

.bio p:last-child {
  margin-bottom: 0;
}

.highlight {
  border-bottom: 1px solid var(--color-gold);
  padding-bottom: 1px;
}

/* Education */
.education h2 {
  font-size: 0.85rem;
  letter-spacing: 0.08em;
  margin-bottom: 1.5rem;
}

.education-list {
  display: flex;
  flex-direction: column;
  gap: 0.5rem;
}

.education-list li {
  font-size: 0.925rem;
  padding-left: 1.25rem;
  position: relative;
  line-height: 1.6;
}

.education-list li::before {
  content: '';
  position: absolute;
  left: 0;
  top: 0.65em;
  width: 5px;
  height: 1px;
  background: var(--color-gold);
}

/* Awards */
.awards {
  margin-top: 2.5rem;
}

.awards h2 {
  font-size: 0.85rem;
  letter-spacing: 0.08em;
  margin-bottom: 1.5rem;
}

.awards-list {
  display: flex;
  flex-direction: column;
  gap: 0;
}

.awards-list li {
  display: flex;
  gap: 1.5rem;
  padding: 0.65rem 0;
  border-bottom: 1px solid color-mix(in srgb, var(--color-border) 50%, transparent);
  align-items: baseline;
}

.awards-list li:last-child {
  border-bottom: none;
}

.award-years {
  font-size: 0.8rem;
  font-weight: 500;
  color: var(--color-gold);
  white-space: nowrap;
  min-width: 90px;
  letter-spacing: 0.02em;
}

.award-detail {
  font-size: 0.9rem;
  line-height: 1.5;
}

.award-detail strong {
  display: block;
  margin-bottom: 0.1rem;
}

.award-detail .muted {
  font-size: 0.82rem;
  line-height: 1.5;
}

.awards-more {
  max-height: 0;
  overflow: hidden;
  transition: max-height 0.5s ease;
}

.awards-more.expanded {
  max-height: 2000px;
}

.awards-toggle {
  background: none;
  border: none;
  cursor: pointer;
  font-size: 0.8rem;
  font-weight: 500;
  color: var(--color-gold);
  letter-spacing: 0.04em;
  padding: 0.75rem 0;
  transition: color 0.2s ease;
}

.awards-toggle:hover {
  color: var(--color-text);
}

/* ============================================
   Publications
   ============================================ */

.pub-category {
  margin-bottom: 2.5rem;
}

.pub-category:last-child {
  margin-bottom: 0;
}

.pub-category > h3 {
  font-size: 0.7rem;
  font-weight: 500;
  text-transform: uppercase;
  letter-spacing: 0.14em;
  color: var(--color-gold);
  margin-bottom: 1.25rem;
  padding-bottom: 0.5rem;
  border-bottom: 1px solid var(--color-border);
}

.pub-item {
  background: transparent;
  border-bottom: 1px solid var(--color-border);
  padding: 1.25rem 0;
  transition: padding-left 0.3s ease;
  position: relative;
}

.pub-item:last-child {
  border-bottom: none;
}

.pub-item:hover {
  padding-left: 1rem;
}

.pub-item::before {
  content: '';
  position: absolute;
  left: 0;
  top: 0;
  bottom: 0;
  width: 2px;
  background: var(--color-gold);
  opacity: 0;
  transition: opacity 0.3s ease;
}

.pub-item:hover::before {
  opacity: 1;
}

.pub-link {
  display: flex;
  align-items: flex-start;
  justify-content: space-between;
  gap: 1.5rem;
  color: var(--color-text);
  text-decoration: none;
  width: 100%;
}

.pub-link:hover {
  color: var(--color-text);
}

.pub-link:hover .pub-citation {
  color: var(--color-text);
}

.pub-content {
  flex: 1;
}

.pub-citation {
  font-size: 0.95rem;
  line-height: 1.6;
  margin-bottom: 0.35rem;
  transition: color 0.2s ease;
}

.pub-description {
  font-size: 0.84rem;
  line-height: 1.6;
  color: var(--color-muted);
  margin-bottom: 0;
}

.pub-badge {
  font-size: 0.65rem;
  font-weight: 500;
  white-space: nowrap;
  padding: 0.2rem 0.6rem;
  border-radius: 2px;
  border: 1px solid var(--color-border);
  background: transparent;
  color: var(--color-muted);
  flex-shrink: 0;
  margin-top: 0.15rem;
  letter-spacing: 0.06em;
  text-transform: uppercase;
}

/* ============================================
   Teaching
   ============================================ */

.teaching-grid {
  display: grid;
  gap: 0;
}

.course-card {
  background: transparent;
  border-bottom: 1px solid var(--color-border);
  padding: 1.75rem 0;
  transition: padding-left 0.3s ease;
}

.course-card:last-child {
  border-bottom: none;
}

.course-card:hover {
  padding-left: 1rem;
}

.course-card h3 {
  font-family: var(--font-heading);
  font-size: 1.15rem;
  font-weight: 400;
  color: var(--color-text);
  margin-bottom: 0.15rem;
}

.course-meta {
  font-size: 0.75rem;
  color: var(--color-gold);
  margin-bottom: 0.75rem;
  letter-spacing: 0.04em;
  text-transform: uppercase;
}

.course-card > p:last-child {
  font-size: 0.9rem;
  margin-bottom: 0;
  color: var(--color-muted);
}

/* ============================================
   Media
   ============================================ */

.media-year {
  margin-bottom: 2.5rem;
}

.media-year:last-child {
  margin-bottom: 0;
}

.media-year > h3 {
  font-size: 0.75rem;
  font-family: var(--font-body);
  font-weight: 500;
  color: var(--color-gold);
  letter-spacing: 0.14em;
  text-transform: uppercase;
  margin-bottom: 0.75rem;
  padding-bottom: 0.5rem;
  border-bottom: 1px solid var(--color-border);
}

.media-list li {
  padding: 0.7rem 0;
  border-bottom: 1px solid color-mix(in srgb, var(--color-border) 50%, transparent);
  display: flex;
  flex-wrap: wrap;
  align-items: baseline;
  gap: 0.75rem;
  transition: padding-left 0.2s ease;
}

.media-list li:hover {
  padding-left: 0.5rem;
}

.media-list li:last-child {
  border-bottom: none;
}

.media-list a {
  font-size: 0.9rem;
  font-weight: 400;
  color: var(--color-text);
  text-decoration: none;
  flex: 1;
  min-width: 200px;
  transition: color 0.2s ease;
}

.media-list a:hover {
  color: var(--color-link);
}

.media-outlet {
  font-size: 0.65rem;
  font-weight: 500;
  text-transform: uppercase;
  letter-spacing: 0.08em;
  color: var(--color-gold);
  white-space: nowrap;
}

.media-date {
  font-size: 0.75rem;
  color: var(--color-muted);
  white-space: nowrap;
}

/* ============================================
   Contact
   ============================================ */

.contact-links {
  display: flex;
  flex-direction: column;
  gap: 0;
}

.contact-item {
  display: inline-flex;
  align-items: center;
  gap: 1rem;
  font-size: 0.9rem;
  font-weight: 400;
  color: var(--color-text);
  text-decoration: none;
  padding: 1rem 0;
  border-bottom: 1px solid var(--color-border);
  transition: padding-left 0.3s ease, color 0.3s ease;
}

.contact-item:last-child {
  border-bottom: none;
}

.contact-item:hover {
  padding-left: 1rem;
  color: var(--color-link);
}

.contact-item svg {
  flex-shrink: 0;
  color: var(--color-gold);
  transition: color 0.3s ease;
}

/* ============================================
   Footer
   ============================================ */

.site-footer {
  padding: 3rem 0;
  border-top: 1px solid var(--color-border);
  text-align: center;
}

.site-footer p {
  font-size: 0.75rem;
  color: var(--color-muted);
  margin: 0;
  letter-spacing: 0.04em;
}

/* ============================================
   Responsive
   ============================================ */

@media (max-width: 768px) {
  .nav-toggle {
    display: flex;
  }

  .nav-links {
    position: fixed;
    top: var(--nav-height);
    left: 0;
    right: 0;
    bottom: 0;
    background: var(--color-bg);
    border-bottom: 1px solid var(--color-border);
    flex-direction: column;
    padding: 2rem 1.5rem;
    gap: 0.25rem;
    transform: translateY(-100%);
    opacity: 0;
    pointer-events: none;
    transition: transform 0.3s ease, opacity 0.3s ease;
    overflow-y: auto;
    -webkit-overflow-scrolling: touch;
  }

  .nav-links.open {
    transform: translateY(0);
    opacity: 1;
    pointer-events: all;
  }

  .nav-links a {
    font-size: 1rem;
    padding: 0.75rem 0;
    display: block;
  }

  .nav-links a::after {
    display: none;
  }

  .hero-grid {
    grid-template-columns: 1fr;
    text-align: center;
  }

  .hero-photo {
    max-width: 180px;
    margin: 0 auto;
  }

  .hero-title {
    font-size: 0.8rem;
  }

  .hero-tagline {
    font-size: 0.95rem;
  }

  .cv-download {
    font-size: 0.75rem;
    padding: 0.45rem 1rem;
  }

  .hero-affiliations {
    font-size: 0.85rem;
  }

  .bio {
    font-size: 0.95rem;
    text-align: left;
  }

  h2 {
    font-size: 1.15rem;
    margin-bottom: 1.75rem;
  }

  .pub-link {
    flex-direction: column;
    gap: 0.5rem;
  }

  .pub-badge {
    align-self: flex-start;
  }

  .pub-item {
    padding: 1rem 0;
  }

  .pub-item:hover {
    padding-left: 0;
  }

  .pub-citation {
    font-size: 0.9rem;
  }

  .pub-description {
    font-size: 0.8rem;
  }

  .course-card {
    padding: 1.25rem 0;
  }

  .course-card:hover {
    padding-left: 0;
  }

  .course-card h3 {
    font-size: 1.05rem;
  }

  .media-list li {
    flex-direction: column;
    gap: 0.25rem;
    padding: 0.6rem 0;
  }

  .media-list li:hover {
    padding-left: 0;
  }

  .media-list a {
    min-width: 0;
    font-size: 0.85rem;
  }

  .awards-list li {
    flex-direction: column;
    gap: 0.15rem;
    padding: 0.55rem 0;
  }

  .award-years {
    min-width: 0;
  }

  .award-detail {
    font-size: 0.85rem;
  }

  .contact-item {
    font-size: 0.85rem;
    padding: 0.85rem 0;
  }

  .contact-item:hover {
    padding-left: 0;
  }

  .section {
    padding: clamp(2.5rem, 6vw, 4rem) 0;
  }

  .site-footer {
    padding: 2rem 0;
  }
}

@media (max-width: 480px) {
  .container {
    padding: 0 1rem;
  }

  h1 {
    font-size: 1.75rem;
  }

  .hero-photo {
    max-width: 150px;
  }

  .nav {
    padding: 0 1rem;
  }

  .education-list li {
    font-size: 0.85rem;
  }

  .award-detail .muted {
    font-size: 0.78rem;
  }
}

/* ============================================
   Prefers color scheme (auto dark mode)
   ============================================ */

@media (prefers-color-scheme: dark) {
  :root:not(.light-mode) {
    --color-bg: #0D1117;
    --color-text: #E2E4E8;
    --color-accent: #E2E4E8;
    --color-accent-hover: #FFFFFF;
    --color-accent-light: #161B22;
    --color-link: #5B8DB8;
    --color-link-hover: #7CAAD0;
    --color-muted: #8B949E;
    --color-border: #21262D;
    --color-surface: #161B22;
    --color-surface-hover: #1C2128;
    --color-badge-bg: #1C2128;
    --color-badge-text: #8B949E;
    --color-gold: #5B8DB8;
    --color-gold-light: #2B4C7E;
  }

  :root:not(.light-mode) .icon-sun { display: none; }
  :root:not(.light-mode) .icon-moon { display: block; }
}

/* ============================================
   Back to top button
   ============================================ */

.back-to-top {
  position: fixed;
  bottom: 2rem;
  right: 2rem;
  width: 40px;
  height: 40px;
  display: flex;
  align-items: center;
  justify-content: center;
  background: var(--color-surface);
  border: 1px solid var(--color-border);
  border-radius: 50%;
  color: var(--color-muted);
  opacity: 0;
  pointer-events: none;
  transition: opacity 0.3s ease, color 0.3s ease;
  z-index: 50;
}

.back-to-top.visible {
  opacity: 1;
  pointer-events: all;
}

.back-to-top:hover {
  color: var(--color-gold);
  border-color: var(--color-gold);
}

/* ============================================
   Print stylesheet
   ============================================ */

@media print {
  *,
  *::before,
  *::after {
    background: transparent !important;
    color: #000 !important;
    box-shadow: none !important;
    text-shadow: none !important;
    transition: none !important;
    animation: none !important;
  }

  body {
    font-size: 11pt;
    line-height: 1.5;
  }

  .site-header,
  .nav-toggle,
  .theme-toggle,
  .back-to-top,
  .cv-download {
    display: none !important;
  }

  .section {
    padding: 1.5rem 0;
    break-inside: avoid;
  }

  .hero-grid {
    grid-template-columns: 120px 1fr;
    gap: 1.5rem;
  }

  .hero-photo img {
    filter: none;
  }

  h1 { font-size: 18pt; }
  h2 { font-size: 13pt; margin-bottom: 0.75rem; }
  h3 { font-size: 11pt; }

  h2::after { display: none; }

  .pub-item { break-inside: avoid; }
  .awards-list li { break-inside: avoid; }

  a[href]::after {
    content: none;
  }

  .fade-in, .stagger > * {
    opacity: 1 !important;
    transform: none !important;
  }
}