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

:root {
  --color-bg: #FFFFFF;
  --color-text: #1A1A1A;
  --color-text-secondary: #4A4A4A;
  --color-accent: #2563EB;
  --color-accent-hover: #1D4ED8;
  --color-border: #E5E5E5;
  --color-bg-subtle: #F9FAFB;
  
  --font-sans: 'IBM Plex Sans', -apple-system, BlinkMacSystemFont, sans-serif;
  --font-mono: 'IBM Plex Mono', monospace;
  
  --content-width: 720px;
  --page-width: 1200px;
  --spacing-xs: 0.5rem;
  --spacing-sm: 1rem;
  --spacing-md: 1.5rem;
  --spacing-lg: 2rem;
  --spacing-xl: 3rem;
  --spacing-2xl: 4rem;
}

html {
  font-size: 16px;
  line-height: 1.6;
  scroll-behavior: smooth;
}

body {
  font-family: var(--font-sans);
  color: var(--color-text);
  background-color: var(--color-bg);
  min-height: 100vh;
  display: flex;
  flex-direction: column;
}

/* Typography */
h1, h2, h3, h4, h5, h6 {
  font-weight: 600;
  line-height: 1.3;
  margin-bottom: var(--spacing-sm);
}

h1 { font-size: 2.441rem; }
h2 { font-size: 1.953rem; }
h3 { font-size: 1.563rem; }
h4 { font-size: 1.25rem; }

p {
  margin-bottom: var(--spacing-sm);
  text-align: justify;
}

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

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

strong {
  font-weight: 600;
}

code {
  font-family: var(--font-mono);
  font-size: 0.875em;
  background: var(--color-bg-subtle);
  padding: 0.125em 0.375em;
  border-radius: 3px;
}

/* Layout */
.container {
  width: 100%;
  max-width: var(--page-width);
  margin: 0 auto;
  padding: 0 var(--spacing-md);
}

main.container {
  max-width: var(--content-width);
  flex: 1;
  padding-top: var(--spacing-xl);
  padding-bottom: var(--spacing-2xl);
}

main.container.container--wide {
  max-width: var(--page-width);
}

.content-narrow {
  max-width: var(--content-width);
  margin: 0 auto;
}

/* Header */
.site-header {
  position: sticky;
  top: 0;
  background: var(--color-bg);
  border-bottom: 1px solid var(--color-border);
  z-index: 100;
}

.header-container {
  display: flex;
  justify-content: space-between;
  align-items: center;
  height: 64px;
  max-width: var(--page-width);
}

.site-logo {
  color: var(--color-text);
  font-weight: 600;
  text-decoration: none;
}

.site-logo:hover {
  color: var(--color-text);
  text-decoration: none;
}

.logo-name {
  font-size: 1.125rem;
}

/* Navigation */
.site-nav {
  display: flex;
  align-items: center;
}

.nav-toggle {
  display: none;
  background: none;
  border: none;
  cursor: pointer;
  padding: var(--spacing-xs);
}

.nav-toggle span {
  display: block;
  width: 24px;
  height: 2px;
  background: var(--color-text);
  margin: 5px 0;
}

.nav-menu {
  display: flex;
  list-style: none;
  gap: var(--spacing-md);
  align-items: center;
}

.nav-menu a {
  color: var(--color-text-secondary);
  font-size: 0.875rem;
  font-weight: 500;
}

.nav-menu a:hover,
.nav-menu a.active {
  color: var(--color-text);
  text-decoration: none;
}

.lang-toggle {
  margin-left: var(--spacing-sm);
  padding-left: var(--spacing-sm);
  border-left: 1px solid var(--color-border);
}

.lang-link {
  font-weight: 600;
  color: var(--color-accent) !important;
}

/* Hero */
.hero {
  text-align: center;
  padding: var(--spacing-2xl) 0;
  border-bottom: 1px solid var(--color-border);
  margin-bottom: var(--spacing-xl);
}

.hero-photo {
  width: 150px;
  height: 150px;
  border-radius: 50%;
  object-fit: cover;
  margin-bottom: var(--spacing-md);
  border: 3px solid var(--color-border);
  background: var(--color-bg-subtle);
}

.hero-title {
  font-size: 1.25rem;
  font-weight: 500;
  color: var(--color-text-secondary);
  margin-bottom: var(--spacing-md);
  text-transform: uppercase;
  letter-spacing: 0.05em;
}

.hero-tagline {
  font-size: 1.563rem;
  font-weight: 600;
  max-width: 600px;
  margin: 0 auto var(--spacing-sm);
}

.hero-current {
  color: var(--color-text-secondary);
  margin-bottom: var(--spacing-lg);
}

.hero p {
  text-align: center;
}

[role="banner"] p {
  text-align: center;
}

/* Buttons */
.btn {
  display: inline-block;
  padding: 0.75rem 1.5rem;
  font-weight: 600;
  font-size: 1rem;
  border-radius: 6px;
  text-decoration: none;
  cursor: pointer;
  border: none;
  font-family: inherit;
}

.btn:hover {
  text-decoration: none;
}

.btn:focus {
  outline: none;
}

.btn:focus-visible {
  outline: 3px solid var(--color-accent-hover);
  outline-offset: 2px;
}

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

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

.btn-nav {
  background: var(--color-accent);
  color: white !important;
  padding: 0.5rem 1rem;
  font-size: 0.875rem;
}

.btn-nav:hover {
  background: var(--color-accent-hover);
  color: white !important;
  text-decoration: none;
}

.btn-linkedin {
  background: #0077B5;
  color: white;
  margin-top: var(--spacing-sm);
}

.btn-linkedin:hover {
  background: #005885;
  color: white;
}

.btn-secondary {
  background: var(--color-bg-subtle);
  color: var(--color-text);
  border: 1px solid var(--color-border);
}

.btn-secondary:hover {
  background: var(--color-border);
  color: var(--color-text);
}

/* Page */
.page-header {
  margin-bottom: var(--spacing-xl);
}

.page-header h1 {
  margin-bottom: var(--spacing-xs);
}

.page-subtitle {
  color: var(--color-text-secondary);
  font-size: 1.125rem;
}

.page-content {
  line-height: 1.7;
}

.page-content h2 {
  margin-top: var(--spacing-xl);
  margin-bottom: var(--spacing-md);
  padding-bottom: var(--spacing-xs);
  border-bottom: 1px solid var(--color-border);
}

.page-content h3 {
  margin-top: var(--spacing-lg);
}

.page-content ul, 
.page-content ol {
  margin-bottom: var(--spacing-sm);
  padding-left: var(--spacing-lg);
}

.page-content li {
  margin-bottom: var(--spacing-xs);
}

/* Intro section (home page) */
.intro {
  font-size: 1.125rem;
  color: var(--color-text-secondary);
}

/* Services */
.services-hero {
  background-image:
    linear-gradient(135deg, rgba(37, 99, 235, 0.5) 0%, rgba(29, 78, 216, 0.9) 100%),
    url('/images/services_bg.png');
  background-size: cover;
  background-position: center;
  border-radius: 14px;
  padding: clamp(2.5rem, 5vw, 3.5rem);
  margin-bottom: var(--spacing-xl);
  color: #fff;
}

.services-hero__eyebrow {
  font-size: 0.875rem;
  font-weight: 600;
  text-transform: uppercase;
  letter-spacing: 0.06em;
  opacity: 0.9;
  margin-bottom: var(--spacing-sm);
}

.services-hero__title {
  font-size: 2rem;
  margin-bottom: var(--spacing-sm);
  line-height: 1.2;
}

.services-hero__description {
  font-size: 1.125rem;
  opacity: 0.95;
  margin-bottom: var(--spacing-md);
  max-width: 600px;
}

.services-hero__details {
  display: grid;
  gap: var(--spacing-xs);
  margin-bottom: var(--spacing-lg);
  font-size: 0.95rem;
}

.services-hero__details p {
  margin: 0;
  text-align: left;
}

.services-hero__details strong {
  opacity: 0.85;
}

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

.services-hero .btn-primary:hover {
  background: rgba(255, 255, 255, 0.9);
  color: var(--color-accent-hover);
}

@media (max-width: 768px) {
  .services-hero {
    border-radius: 10px;
  }

  .services-hero__title {
    font-size: 1.75rem;
  }
}

.services-section__title {
  font-size: 1.25rem;
  font-weight: 600;
  color: var(--color-text-secondary);
  margin-bottom: var(--spacing-lg);
  text-transform: uppercase;
  letter-spacing: 0.03em;
}

.services-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
  gap: var(--spacing-lg);
}

.service-card {
  background: var(--color-bg-subtle);
  padding: var(--spacing-lg);
  border-radius: 8px;
  display: flex;
  flex-direction: column;
}

.service-card__title {
  font-size: 1.25rem;
  margin-bottom: var(--spacing-sm);
}

.service-card__meta {
  font-size: 0.9rem;
  color: var(--color-text-secondary);
  margin-bottom: var(--spacing-sm);
  flex-grow: 1;
}

.service-card__meta p {
  margin-bottom: var(--spacing-xs);
  text-align: left;
}

.service-card .btn-secondary {
  align-self: flex-start;
  margin-top: auto;
}

/* Cards */
.card-grid {
  display: grid;
  gap: var(--spacing-lg);
  margin-top: var(--spacing-lg);
}

.card {
  background: var(--color-bg-subtle);
  padding: var(--spacing-lg);
  border-radius: 8px;
}

.card h3 {
  margin-bottom: var(--spacing-xs);
}

.card h3 a {
  color: var(--color-text);
}

.card h3 a:hover {
  color: var(--color-accent);
}

.card-tags {
  margin-top: var(--spacing-sm);
  display: flex;
  flex-wrap: wrap;
  gap: var(--spacing-xs);
}

.tag {
  font-size: 0.75rem;
  background: var(--color-border);
  padding: 0.25em 0.5em;
  border-radius: 3px;
}

/* Talk/Publication list */
.item-list {
  list-style: none;
  padding: 0;
}

.item-list li {
  padding: var(--spacing-md) 0;
  border-bottom: 1px solid var(--color-border);
}

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

.item-list li.pub-item {
  display: grid;
  grid-template-columns: 120px 1fr;
  gap: var(--spacing-md);
}

.pub-thumbnail {
  width: 120px;
  background: var(--color-bg-subtle);
  border-radius: 4px;
  overflow: hidden;
}

.pub-thumbnail img {
  display: block;
  width: 100%;
  height: auto;
}

.pub-links {
  font-size: 0.875rem;
}

@media (max-width: 480px) {
  .item-list li.pub-item {
    grid-template-columns: 1fr;
  }

  .pub-thumbnail {
    width: 100%;
  }
}

.item-date {
  font-size: 0.875rem;
  color: var(--color-text-secondary);
}

.item-venue {
  font-style: italic;
  color: var(--color-text-secondary);
}

/* Community */
.community-item {
  margin-bottom: var(--spacing-lg);
}

.community-item h3 {
  margin-bottom: var(--spacing-xs);
}

.community-table {
  display: grid;
  gap: var(--spacing-lg);
  margin-top: var(--spacing-lg);
}

.community-row {
  display: grid;
  grid-template-columns: 80px 1fr;
  gap: var(--spacing-md);
  align-items: start;
  padding: var(--spacing-md);
  background: var(--color-bg-subtle);
  border-radius: 8px;
}

.community-logo {
  width: 80px;
  height: 80px;
  background: var(--color-border);
  border-radius: 8px;
  display: flex;
  align-items: center;
  justify-content: center;
  color: var(--color-text-secondary);
  font-size: 0.75rem;
}

.community-logo img {
  width: 100%;
  height: 100%;
  object-fit: contain;
  border-radius: 8px;
}

.community-info h3 {
  margin-top: 0;
  margin-bottom: var(--spacing-xs);
}

.community-info p {
  margin-bottom: var(--spacing-xs);
  color: var(--color-text-secondary);
}

/* About profile header */
.about-profile {
  display: grid;
  grid-template-columns: 260px 1fr;
  gap: var(--spacing-lg);
  align-items: center;
  padding: var(--spacing-lg);
  margin-bottom: var(--spacing-xl);
  background: var(--color-bg-subtle);
  border: 1px solid var(--color-border);
  border-radius: 14px;
}

.about-profile p {
  text-align: left;
}

.about-profile__media {
  display: flex;
  justify-content: center;
}

.about-profile__photo {
  width: 240px;
  height: 240px;
  border-radius: 999px;
  object-fit: cover;
  border: 3px solid var(--color-border);
  background: var(--color-bg);
}

.about-profile__eyebrow {
  font-size: 0.875rem;
  font-weight: 600;
  text-transform: uppercase;
  letter-spacing: 0.06em;
  color: var(--color-text-secondary);
  margin: 0 0 var(--spacing-xs);
}

.about-profile__title {
  margin: 0 0 var(--spacing-xs);
}

.about-profile__subtitle {
  margin: 0 0 var(--spacing-sm);
  color: var(--color-text-secondary);
  font-size: 1.0625rem;
  max-width: 60ch;
}

.about-profile__location {
  margin: 0 0 var(--spacing-md);
  color: var(--color-text-secondary);
  font-size: 0.95rem;
}

@media (max-width: 768px) {
  .about-profile {
    grid-template-columns: 1fr;
    text-align: center;
  }

  .about-profile p {
    text-align: center;
  }

  .about-profile__subtitle {
    margin-left: auto;
    margin-right: auto;
  }
}

/* About page */
.about-intro {
  display: flex;
  gap: var(--spacing-lg);
  align-items: flex-start;
  margin-bottom: var(--spacing-lg);
}

.about-photo {
  flex-shrink: 0;
}

.profile-photo {
  width: 150px;
  height: 150px;
  border-radius: 50%;
  object-fit: cover;
  border: 3px solid var(--color-border);
  background: var(--color-bg-subtle);
}

.about-text {
  flex: 1;
}

.timeline-image {
  width: 100%;
  max-width: 100%;
  height: auto;
  margin-top: var(--spacing-md);
  border-radius: 8px;
}

/* Communities hero */
.communities-hero {
  border-radius: 14px;
  overflow: hidden;
  padding: clamp(3rem, 6vw, 4.5rem) 0;
  margin-bottom: var(--spacing-xl);
  color: #fff;
  background-image:
    linear-gradient(180deg, rgba(0, 0, 0, 0.55), rgba(0, 0, 0, 0.55)),
    url('/images/communities-hero-pycones-2022.jpg');
  background-size: cover;
  background-position: center 40%;
}

.communities-hero__inner {
  max-width: 860px;
  margin: 0 auto;
  padding: 0 var(--spacing-md);
  text-align: center;
}

.communities-hero__eyebrow {
  font-size: 0.875rem;
  font-weight: 600;
  text-transform: uppercase;
  letter-spacing: 0.06em;
  opacity: 0.9;
  margin-bottom: var(--spacing-sm);
}

.communities-hero__title {
  margin-bottom: var(--spacing-sm);
  font-size: 2.2rem;
  line-height: 1.15;
}

.communities-hero__subtitle {
  font-size: 1.125rem;
  margin: 0 auto var(--spacing-sm);
  opacity: 0.95;
}

.communities-hero__topics {
  font-size: 1rem;
  margin: 0 auto var(--spacing-md);
  opacity: 0.85;
}

.communities-hero__badges {
  display: flex;
  flex-wrap: wrap;
  justify-content: center;
  gap: var(--spacing-xs);
  margin-bottom: var(--spacing-lg);
}

.communities-hero__badge {
  font-size: 0.875rem;
  padding: 0.35rem 0.65rem;
  border-radius: 999px;
  background: rgba(255, 255, 255, 0.12);
  border: 1px solid rgba(255, 255, 255, 0.22);
  backdrop-filter: blur(6px);
}

.communities-hero__cta {
  display: flex;
  justify-content: center;
}

@media (max-width: 768px) {
  .communities-hero {
    border-radius: 10px;
  }

  .communities-hero__title {
    font-size: 1.75rem;
  }

  .communities-hero__subtitle,
  .communities-hero__topics {
    font-size: 1rem;
  }
}

/* Talks hero */
.talks-hero {
  border-radius: 14px;
  overflow: hidden;
  padding: clamp(3rem, 6vw, 4.5rem) 0;
  margin-bottom: var(--spacing-xl);
  color: #fff;
  background-image:
    linear-gradient(180deg, rgba(0, 0, 0, 0.55), rgba(0, 0, 0, 0.55)),
    url('/images/talks-hero-databeers-2023.jpg');
  background-size: cover;
  background-position: center 35%;
}

.talks-hero__inner {
  max-width: 860px;
  margin: 0 auto;
  padding: 0 var(--spacing-md);
  text-align: center;
}

.talks-hero__eyebrow {
  font-size: 0.875rem;
  font-weight: 600;
  text-transform: uppercase;
  letter-spacing: 0.06em;
  opacity: 0.9;
  margin-bottom: var(--spacing-sm);
}

.talks-hero__title {
  margin-bottom: var(--spacing-sm);
  font-size: 2.2rem;
  line-height: 1.15;
}

.talks-hero__subtitle {
  font-size: 1.125rem;
  margin: 0 auto var(--spacing-sm);
  opacity: 0.95;
}

.talks-hero__topics {
  font-size: 1rem;
  margin: 0 auto var(--spacing-md);
  opacity: 0.85;
}

.talks-hero__badges {
  display: flex;
  flex-wrap: wrap;
  justify-content: center;
  gap: var(--spacing-xs);
  margin-bottom: var(--spacing-lg);
}

.talks-hero__badge {
  font-size: 0.875rem;
  padding: 0.35rem 0.65rem;
  border-radius: 999px;
  background: rgba(255, 255, 255, 0.12);
  border: 1px solid rgba(255, 255, 255, 0.22);
  backdrop-filter: blur(6px);
}

.talks-hero__cta {
  display: flex;
  justify-content: center;
}

@media (max-width: 768px) {
  .talks-hero {
    border-radius: 10px;
  }

  .talks-hero__title {
    font-size: 1.75rem;
  }

  .talks-hero__subtitle,
  .talks-hero__topics {
    font-size: 1rem;
  }
}

/* Talks with images */
.talk-item {
  display: grid;
  grid-template-columns: 120px 1fr;
  gap: var(--spacing-md);
  padding: var(--spacing-md) 0;
  border-bottom: 1px solid var(--color-border);
}

/* Publications hero */
.publications-hero {
  border-radius: 14px;
  overflow: hidden;
  padding: clamp(3rem, 6vw, 4.5rem) 0;
  margin-bottom: var(--spacing-xl);
  color: #fff;
  background-image:
    linear-gradient(180deg, rgba(0, 0, 0, 0.6), rgba(0, 0, 0, 0.6)),
    url('/images/publications-hero-neural-network.png');
  background-size: cover;
  background-position: center;
}

.publications-hero__inner {
  max-width: 860px;
  margin: 0 auto;
  padding: 0 var(--spacing-md);
  text-align: center;
}

.publications-hero__eyebrow {
  font-size: 0.875rem;
  font-weight: 600;
  text-transform: uppercase;
  letter-spacing: 0.06em;
  opacity: 0.9;
  margin-bottom: var(--spacing-sm);
}

.publications-hero__title {
  margin-bottom: var(--spacing-sm);
  font-size: 2.2rem;
  line-height: 1.15;
}

.publications-hero__subtitle {
  font-size: 1.125rem;
  margin: 0 auto var(--spacing-sm);
  opacity: 0.95;
}

.publications-hero__topics {
  font-size: 1rem;
  margin: 0 auto var(--spacing-md);
  opacity: 0.85;
}

.publications-hero__badges {
  display: flex;
  flex-wrap: wrap;
  justify-content: center;
  gap: var(--spacing-xs);
  margin-bottom: var(--spacing-lg);
}

.publications-hero__badge {
  font-size: 0.875rem;
  padding: 0.35rem 0.65rem;
  border-radius: 999px;
  background: rgba(255, 255, 255, 0.12);
  border: 1px solid rgba(255, 255, 255, 0.22);
  backdrop-filter: blur(6px);
}

.publications-hero__cta {
  display: flex;
  justify-content: center;
}

@media (max-width: 768px) {
  .publications-hero {
    border-radius: 10px;
  }

  .publications-hero__title {
    font-size: 1.75rem;
  }

  .publications-hero__subtitle,
  .publications-hero__topics {
    font-size: 1rem;
  }
}

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

.talk-thumbnail {
  width: 120px;
  background: var(--color-bg-subtle);
  border-radius: 4px;
  overflow: hidden;
}

.talk-thumbnail img {
  width: 100%;
  height: auto;
  display: block;
}

.talk-info strong {
  display: block;
  margin-bottom: var(--spacing-xs);
}

/* Speaker photos */
.speaker-photos {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
  gap: var(--spacing-md);
  margin: var(--spacing-lg) 0;
}

.speaker-photos img {
  width: 100%;
  height: auto;
  border-radius: 8px;
  box-shadow: 0 2px 8px rgba(0, 0, 0, 0.1);
}

@media (max-width: 480px) {
  .about-intro {
    flex-direction: column;
    align-items: center;
    text-align: center;
  }
  
  .community-row {
    grid-template-columns: 1fr;
    text-align: center;
  }
  
  .community-logo {
    margin: 0 auto;
  }
  
  .talk-item {
    grid-template-columns: 1fr;
  }
  
  .talk-thumbnail {
    width: 100%;
    height: auto;
  }
}

/* Contact */
.contact-info {
  margin: var(--spacing-lg) 0;
}

.contact-info p {
  margin-bottom: var(--spacing-xs);
}

.contact-cta {
  margin-top: var(--spacing-xl);
}

/* Footer */
.site-footer {
  background: var(--color-bg-subtle);
  border-top: 1px solid var(--color-border);
  padding: var(--spacing-lg) 0;
  margin-top: auto;
}

.footer-content {
  display: flex;
  justify-content: space-between;
  align-items: center;
  flex-wrap: wrap;
  gap: var(--spacing-sm);
}

.footer-social {
  display: flex;
  gap: var(--spacing-md);
}

.footer-social a {
  color: var(--color-text-secondary);
  font-size: 0.875rem;
}

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

.footer-legal {
  display: flex;
  gap: var(--spacing-md);
}

.footer-legal a {
  color: var(--color-text-secondary);
  font-size: 0.875rem;
}

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

.footer-copyright {
  color: var(--color-text-secondary);
  font-size: 0.875rem;
  margin: 0;
}

/* Responsive */
@media (max-width: 768px) {
  html {
    font-size: 15px;
  }
  
  .header-container {
    position: relative;
  }
  
  .nav-toggle {
    display: block;
  }
  
  .nav-menu {
    display: none;
    position: absolute;
    top: 100%;
    left: 0;
    right: 0;
    background: var(--color-bg);
    border-bottom: 1px solid var(--color-border);
    flex-direction: column;
    padding: var(--spacing-md);
    gap: var(--spacing-sm);
  }
  
  .nav-menu.is-open {
    display: flex;
  }
  
  .lang-toggle {
    margin-left: 0;
    padding-left: 0;
    border-left: none;
    padding-top: var(--spacing-sm);
    border-top: 1px solid var(--color-border);
  }
  
  .hero {
    padding: var(--spacing-xl) 0;
  }
  
  .hero-tagline {
    font-size: 1.25rem;
  }
  
  .footer-content {
    flex-direction: column;
    text-align: center;
  }
}

@media (max-width: 480px) {
  h1 { font-size: 1.953rem; }
  h2 { font-size: 1.563rem; }
  h3 { font-size: 1.25rem; }
}