/* ==========================================================================
   Florian Thürkow – Personal Website
   Design System & Styles v2.0
   ========================================================================== */

/* --- CSS Custom Properties --- */
:root {
  --color-primary: #1a3a4a;
  --color-primary-light: #24526a;
  --color-primary-dark: #122a36;
  --color-accent: #c9963b;
  --color-accent-light: #dbb06a;
  --color-accent-glow: rgba(201, 150, 59, 0.15);
  --color-text: #2d2d2d;
  --color-text-light: #5a5a5a;
  --color-text-muted: #8a8a8a;
  --color-bg: #fafaf8;
  --color-bg-alt: #f0efeb;
  --color-bg-card: #ffffff;
  --color-border: #e0ddd6;
  --color-border-light: #eae8e2;

  --font-heading: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', sans-serif;
  --font-body: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', sans-serif;
  --font-mono: 'JetBrains Mono', 'Fira Code', 'Consolas', monospace;

  --space-xs: 0.5rem;
  --space-sm: 1rem;
  --space-md: 1.5rem;
  --space-lg: 2.5rem;
  --space-xl: 4rem;
  --space-2xl: 6rem;

  --max-width: 1120px;
  --max-width-narrow: 780px;

  --radius: 6px;
  --radius-lg: 12px;
  --radius-xl: 20px;

  --shadow-sm: 0 1px 3px rgba(0,0,0,0.06);
  --shadow-md: 0 4px 12px rgba(0,0,0,0.08);
  --shadow-lg: 0 8px 30px rgba(0,0,0,0.1);
  --shadow-glow: 0 0 40px rgba(201, 150, 59, 0.12);

  --transition: 0.25s ease;
  --transition-slow: 0.4s cubic-bezier(0.25, 0.46, 0.45, 0.94);
}

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

html {
  font-size: 16px;
  scroll-behavior: smooth;
  -webkit-text-size-adjust: 100%;
}

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

img { max-width: 100%; height: auto; display: block; }
a { color: var(--color-primary); text-decoration: none; transition: color var(--transition); }
a:hover { color: var(--color-accent); }

h1, h2, h3, h4 {
  font-family: var(--font-heading);
  font-weight: 600;
  line-height: 1.3;
  color: var(--color-primary);
}

h1 { font-size: clamp(1.8rem, 4vw, 2.8rem); }
h2 { font-size: clamp(1.4rem, 3vw, 2rem); margin-bottom: var(--space-md); }
h3 { font-size: clamp(1.1rem, 2vw, 1.35rem); margin-bottom: var(--space-sm); }

p { margin-bottom: var(--space-sm); }

::selection {
  background: var(--color-accent-glow);
  color: var(--color-primary);
}

/* --- Skip Link --- */
.skip-link {
  position: absolute;
  top: -100%;
  left: var(--space-sm);
  background: var(--color-primary);
  color: #fff;
  padding: var(--space-xs) var(--space-sm);
  border-radius: var(--radius);
  z-index: 1000;
}
.skip-link:focus { top: var(--space-sm); color: #fff; }

/* --- Layout --- */
.container { max-width: var(--max-width); margin: 0 auto; padding: 0 var(--space-md); }
.container--narrow { max-width: var(--max-width-narrow); }

.section {
  padding: var(--space-xl) 0;
}
.section--alt {
  background: var(--color-bg-alt);
}

.section__label {
  font-size: 0.75rem;
  font-weight: 600;
  letter-spacing: 0.12em;
  text-transform: uppercase;
  color: var(--color-accent);
  margin-bottom: var(--space-xs);
}

/* --- Header / Navigation --- */
.site-header {
  position: sticky;
  top: 0;
  z-index: 100;
  background: rgba(250, 250, 248, 0.92);
  backdrop-filter: blur(12px);
  -webkit-backdrop-filter: blur(12px);
  border-bottom: 1px solid var(--color-border-light);
  transition: box-shadow var(--transition);
}
.site-header.is-scrolled {
  box-shadow: var(--shadow-sm);
}

.site-header__inner {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: var(--space-sm) var(--space-md);
  max-width: var(--max-width);
  margin: 0 auto;
}

.site-header__logo {
  font-family: var(--font-heading);
  font-weight: 700;
  font-size: 1.1rem;
  color: var(--color-primary);
  white-space: nowrap;
  text-decoration: none;
}
.site-header__logo:hover { color: var(--color-primary); }
.site-header__logo span { color: var(--color-accent); }

.main-nav { display: flex; gap: var(--space-md); align-items: center; }
.main-nav a {
  font-size: 0.9rem;
  font-weight: 500;
  color: var(--color-text-light);
  transition: color var(--transition);
  position: relative;
  padding: 0.2rem 0;
}
.main-nav a::after {
  content: '';
  position: absolute;
  bottom: -2px;
  left: 50%;
  right: 50%;
  height: 2px;
  background: var(--color-accent);
  border-radius: 1px;
  transition: left var(--transition), right var(--transition);
}
.main-nav a:hover::after,
.main-nav a.active::after {
  left: 0;
  right: 0;
}
.main-nav a:hover, .main-nav a.active {
  color: var(--color-primary);
}

/* Mobile Nav Toggle */
.nav-toggle {
  display: none;
  background: none;
  border: none;
  cursor: pointer;
  padding: var(--space-xs);
  z-index: 101;
}
.nav-toggle span {
  display: block;
  width: 22px;
  height: 2px;
  background: var(--color-primary);
  margin: 5px 0;
  transition: transform var(--transition), opacity var(--transition);
  border-radius: 2px;
}

@media (max-width: 768px) {
  .nav-toggle { display: block; }
  .main-nav {
    display: none;
    position: absolute;
    top: 100%;
    left: 0;
    right: 0;
    background: rgba(250, 250, 248, 0.98);
    backdrop-filter: blur(12px);
    -webkit-backdrop-filter: blur(12px);
    flex-direction: column;
    padding: var(--space-md);
    border-bottom: 1px solid var(--color-border);
    box-shadow: var(--shadow-md);
    gap: var(--space-sm);
  }
  .main-nav.is-open { display: flex; }
  .main-nav a { font-size: 1rem; padding: 0.4rem 0; }
  .main-nav a::after { display: none; }
}

/* --- Hero --- */
.hero {
  padding: var(--space-2xl) 0 var(--space-xl);
  position: relative;
  overflow: hidden;
}
.hero::before {
  content: '';
  position: absolute;
  top: -60%;
  right: -20%;
  width: 600px;
  height: 600px;
  background: radial-gradient(circle, var(--color-accent-glow) 0%, transparent 70%);
  border-radius: 50%;
  pointer-events: none;
  z-index: 0;
}

.hero__grid {
  display: grid;
  grid-template-columns: 1fr 300px;
  gap: var(--space-xl);
  align-items: center;
  position: relative;
  z-index: 1;
}

.hero__content { position: relative; }

.hero__pretitle {
  font-size: 0.8rem;
  font-weight: 600;
  letter-spacing: 0.1em;
  text-transform: uppercase;
  color: var(--color-accent);
  margin-bottom: var(--space-xs);
}
.hero__title {
  font-size: clamp(2rem, 5vw, 3.2rem);
  font-weight: 700;
  line-height: 1.15;
  margin-bottom: var(--space-sm);
  background: linear-gradient(135deg, var(--color-primary) 0%, var(--color-primary-light) 100%);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
}
.hero__subtitle {
  font-size: clamp(1rem, 2vw, 1.2rem);
  color: var(--color-text-light);
  margin-bottom: var(--space-lg);
  max-width: 540px;
}
.hero__actions {
  display: flex;
  gap: 1rem;
  flex-wrap: wrap;
}

.hero__photo-wrap {
  position: relative;
  display: flex;
  justify-content: center;
}
.hero__photo-wrap::before {
  content: '';
  position: absolute;
  inset: -8px;
  border-radius: 50%;
  background: linear-gradient(135deg, var(--color-accent) 0%, var(--color-primary-light) 100%);
  opacity: 0.2;
  z-index: 0;
}
.hero__photo {
  width: 280px;
  height: 280px;
  border-radius: 50%;
  object-fit: cover;
  object-position: center 20%;
  border: 4px solid var(--color-bg);
  box-shadow: var(--shadow-lg);
  position: relative;
  z-index: 1;
}

@media (max-width: 768px) {
  .hero { padding: var(--space-xl) 0; }
  .hero__grid {
    grid-template-columns: 1fr;
    text-align: center;
  }
  .hero__photo-wrap {
    order: -1;
    margin-bottom: var(--space-md);
  }
  .hero__photo {
    width: 200px;
    height: 200px;
  }
  .hero__subtitle { margin-left: auto; margin-right: auto; }
  .hero__actions { justify-content: center; }
}

/* --- Entry Cards (3-column) --- */
.entry-cards {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: var(--space-md);
}
.entry-card {
  background: var(--color-bg-card);
  border: 1px solid var(--color-border-light);
  border-radius: var(--radius-lg);
  padding: var(--space-lg) var(--space-md);
  transition: box-shadow var(--transition), transform var(--transition), border-color var(--transition);
  position: relative;
  overflow: hidden;
}
.entry-card::before {
  content: '';
  position: absolute;
  top: 0;
  left: 0;
  right: 0;
  height: 3px;
  background: linear-gradient(90deg, var(--color-accent), var(--color-primary-light));
  transform: scaleX(0);
  transform-origin: left;
  transition: transform var(--transition-slow);
}
.entry-card:hover::before { transform: scaleX(1); }
.entry-card:hover {
  box-shadow: var(--shadow-md);
  transform: translateY(-4px);
  border-color: var(--color-border);
}
.entry-card__icon {
  font-size: 2rem;
  margin-bottom: var(--space-sm);
  display: inline-flex;
  align-items: center;
  justify-content: center;
  width: 52px;
  height: 52px;
  background: var(--color-accent-glow);
  border-radius: var(--radius-lg);
}
.entry-card__title {
  font-size: 1.1rem;
  font-weight: 600;
  margin-bottom: var(--space-xs);
  color: var(--color-primary);
}
.entry-card__text {
  font-size: 0.9rem;
  color: var(--color-text-light);
  margin-bottom: var(--space-sm);
}
.entry-card__link {
  font-size: 0.85rem;
  font-weight: 600;
  color: var(--color-accent);
  display: inline-flex;
  align-items: center;
  gap: 0.3rem;
  transition: gap var(--transition);
}
.entry-card__link:hover { gap: 0.6rem; color: var(--color-accent); }

@media (max-width: 768px) {
  .entry-cards { grid-template-columns: 1fr; }
}

/* --- Publication List --- */
.pub-list { list-style: none; }
.pub-item {
  padding: var(--space-md) 0;
  border-bottom: 1px solid var(--color-border-light);
  display: grid;
  gap: 0.2rem;
  transition: background var(--transition);
}
.pub-item:last-child { border-bottom: none; }
.pub-item__year {
  font-size: 0.75rem;
  font-weight: 600;
  color: var(--color-accent);
  text-transform: uppercase;
  letter-spacing: 0.08em;
}
.pub-item__title {
  font-weight: 600;
  font-size: 1rem;
  color: var(--color-primary);
}
.pub-item__meta {
  font-size: 0.85rem;
  color: var(--color-text-light);
}
.pub-item__doi {
  font-size: 0.8rem;
  font-family: var(--font-mono);
  color: var(--color-accent);
}

/* --- Lecture Preview System --- */
.lecture-previews {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(340px, 1fr));
  gap: var(--space-lg);
}

.lecture-preview {
  background: var(--color-bg-card);
  border: 1px solid var(--color-border-light);
  border-radius: var(--radius-xl);
  overflow: hidden;
  transition: box-shadow var(--transition-slow), transform var(--transition-slow);
  position: relative;
}
.lecture-preview:hover {
  box-shadow: var(--shadow-lg), var(--shadow-glow);
  transform: translateY(-6px);
}

/* Slide preview area */
.lecture-preview__slide {
  position: relative;
  aspect-ratio: 16 / 9;
  background: var(--color-primary);
  overflow: hidden;
  display: flex;
  align-items: center;
  justify-content: center;
  padding: var(--space-md);
}
.lecture-preview__slide-bg {
  position: absolute;
  inset: 0;
  opacity: 0.08;
  background-size: 30px 30px;
  background-image:
    linear-gradient(to right, rgba(255,255,255,0.1) 1px, transparent 1px),
    linear-gradient(to bottom, rgba(255,255,255,0.1) 1px, transparent 1px);
}

/* SVG/Visual content inside slide */
.lecture-preview__visual {
  position: relative;
  z-index: 1;
  width: 100%;
  height: 100%;
  display: flex;
  flex-direction: column;
  justify-content: center;
  align-items: center;
  color: #fff;
  text-align: center;
  gap: 0.5rem;
}
.lecture-preview__visual-icon {
  font-size: 2.5rem;
  opacity: 0.9;
  margin-bottom: 0.25rem;
}
.lecture-preview__visual-title {
  font-family: var(--font-heading);
  font-size: 1.1rem;
  font-weight: 700;
  color: #fff;
  line-height: 1.3;
}
.lecture-preview__visual-subtitle {
  font-size: 0.75rem;
  color: rgba(255,255,255,0.6);
  font-weight: 500;
  letter-spacing: 0.05em;
  text-transform: uppercase;
}
.lecture-preview__visual-keywords {
  display: flex;
  flex-wrap: wrap;
  gap: 0.4rem;
  justify-content: center;
  margin-top: 0.5rem;
}
.lecture-preview__keyword {
  font-size: 0.65rem;
  font-weight: 600;
  padding: 0.2rem 0.6rem;
  border-radius: 100px;
  background: rgba(255,255,255,0.12);
  color: rgba(255,255,255,0.8);
  border: 1px solid rgba(255,255,255,0.15);
  letter-spacing: 0.03em;
}

/* Decorative gradient strip */
.lecture-preview__accent {
  height: 4px;
  background: linear-gradient(90deg, var(--color-accent), var(--color-accent-light), var(--color-primary-light));
}

/* Card body */
.lecture-preview__body {
  padding: var(--space-md);
}
.lecture-preview__tag {
  font-size: 0.65rem;
  font-weight: 600;
  letter-spacing: 0.1em;
  text-transform: uppercase;
  color: var(--color-accent);
  margin-bottom: 0.25rem;
}
.lecture-preview__title {
  font-size: 1.1rem;
  font-weight: 700;
  color: var(--color-primary);
  margin-bottom: var(--space-xs);
}
.lecture-preview__desc {
  font-size: 0.85rem;
  color: var(--color-text-light);
  margin-bottom: var(--space-sm);
  line-height: 1.6;
}
.lecture-preview__topics {
  list-style: none;
  display: flex;
  flex-wrap: wrap;
  gap: 0.4rem;
}
.lecture-preview__topics li {
  font-size: 0.75rem;
  font-weight: 500;
  padding: 0.25rem 0.7rem;
  border-radius: var(--radius);
  background: var(--color-bg-alt);
  color: var(--color-text);
  border: 1px solid var(--color-border-light);
  transition: background var(--transition), color var(--transition);
}
.lecture-preview:hover .lecture-preview__topics li {
  background: var(--color-accent-glow);
  border-color: var(--color-accent-light);
}

/* Slide themes for variety */
.lecture-preview__slide--db { background: linear-gradient(135deg, #1a3a4a 0%, #24526a 100%); }
.lecture-preview__slide--erp { background: linear-gradient(135deg, #2d4a1a 0%, #4a6a24 100%); }
.lecture-preview__slide--gis { background: linear-gradient(135deg, #3a1a4a 0%, #5a2470 100%); }
.lecture-preview__slide--re { background: linear-gradient(135deg, #4a2a1a 0%, #6a4024 100%); }
.lecture-preview__slide--ai { background: linear-gradient(135deg, #1a2a4a 0%, #243a6a 100%); }
.lecture-preview__slide--p4 { background: linear-gradient(135deg, #1a4a3a 0%, #246a52 100%); }

/* Old lecture cards (backward compat) */
.lecture-cards {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(300px, 1fr));
  gap: var(--space-md);
}
.lecture-card {
  background: var(--color-bg-card);
  border: 1px solid var(--color-border-light);
  border-radius: var(--radius-lg);
  overflow: hidden;
  transition: box-shadow var(--transition), transform var(--transition);
}
.lecture-card:hover {
  box-shadow: var(--shadow-md);
  transform: translateY(-3px);
}
.lecture-card__header {
  background: var(--color-primary);
  color: #fff;
  padding: var(--space-md);
  position: relative;
}
.lecture-card__header::after {
  content: '';
  position: absolute;
  bottom: 0;
  left: 0;
  right: 0;
  height: 3px;
  background: linear-gradient(90deg, var(--color-accent), var(--color-accent-light));
}
.lecture-card__tag {
  font-size: 0.7rem;
  font-weight: 600;
  letter-spacing: 0.1em;
  text-transform: uppercase;
  opacity: 0.7;
}
.lecture-card__title {
  font-size: 1.15rem;
  font-weight: 700;
  color: #fff;
  margin-top: 0.25rem;
}
.lecture-card__body {
  padding: var(--space-md);
}
.lecture-card__desc {
  font-size: 0.9rem;
  color: var(--color-text-light);
  margin-bottom: var(--space-sm);
}
.lecture-card__highlights {
  list-style: none;
  margin-bottom: var(--space-sm);
}
.lecture-card__highlights li {
  font-size: 0.85rem;
  color: var(--color-text);
  padding: 0.2rem 0;
  padding-left: 1.2rem;
  position: relative;
}
.lecture-card__highlights li::before {
  content: '\2192';
  position: absolute;
  left: 0;
  color: var(--color-accent);
  font-weight: 600;
}

/* --- Trust Anchors --- */
.trust-bar {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: var(--space-md);
  text-align: center;
}
.trust-item {
  padding: var(--space-md);
  border-radius: var(--radius-lg);
  transition: background var(--transition);
}
.trust-item:hover { background: var(--color-bg-alt); }
.trust-item__value {
  font-size: 1.6rem;
  font-weight: 700;
  color: var(--color-primary);
  line-height: 1.2;
}
.trust-item__label {
  font-size: 0.8rem;
  color: var(--color-text-light);
  margin-top: 0.25rem;
}

@media (max-width: 768px) {
  .trust-bar { grid-template-columns: repeat(2, 1fr); gap: var(--space-sm); }
}

/* --- Timeline (CV) --- */
.timeline { list-style: none; position: relative; padding-left: var(--space-lg); }
.timeline::before {
  content: '';
  position: absolute;
  left: 8px;
  top: 0;
  bottom: 0;
  width: 2px;
  background: linear-gradient(to bottom, var(--color-accent), var(--color-border));
}
.timeline__item {
  position: relative;
  margin-bottom: var(--space-lg);
  transition: transform var(--transition);
}
.timeline__item:hover { transform: translateX(4px); }
.timeline__item::before {
  content: '';
  position: absolute;
  left: calc(-1 * var(--space-lg) + 4px);
  top: 6px;
  width: 10px;
  height: 10px;
  border-radius: 50%;
  background: var(--color-accent);
  border: 2px solid var(--color-bg);
  box-shadow: 0 0 0 3px var(--color-accent-glow);
}
.timeline__period {
  font-size: 0.8rem;
  font-weight: 600;
  color: var(--color-accent);
}
.timeline__role {
  font-size: 1.05rem;
  font-weight: 600;
  color: var(--color-primary);
  margin: 0.15rem 0;
}
.timeline__institution {
  font-size: 0.9rem;
  color: var(--color-text-light);
  margin-bottom: 0.25rem;
}
.timeline__desc {
  font-size: 0.85rem;
  color: var(--color-text-muted);
}

/* --- Project Cards --- */
.project-cards {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(340px, 1fr));
  gap: var(--space-md);
}
.project-card {
  background: var(--color-bg-card);
  border: 1px solid var(--color-border-light);
  border-radius: var(--radius-lg);
  padding: var(--space-lg) var(--space-md);
  transition: box-shadow var(--transition), transform var(--transition);
  position: relative;
  overflow: hidden;
}
.project-card::after {
  content: '';
  position: absolute;
  top: 0;
  left: 0;
  width: 3px;
  height: 100%;
  background: linear-gradient(to bottom, var(--color-accent), transparent);
  opacity: 0;
  transition: opacity var(--transition);
}
.project-card:hover { box-shadow: var(--shadow-md); transform: translateY(-3px); }
.project-card:hover::after { opacity: 1; }
.project-card__period {
  font-size: 0.75rem;
  font-weight: 600;
  color: var(--color-accent);
  text-transform: uppercase;
  letter-spacing: 0.08em;
}
.project-card__title {
  font-size: 1.15rem;
  font-weight: 700;
  color: var(--color-primary);
  margin: 0.25rem 0;
}
.project-card__subtitle {
  font-size: 0.9rem;
  color: var(--color-text-light);
  margin-bottom: var(--space-sm);
}
.project-card__funding {
  display: inline-block;
  font-size: 0.8rem;
  font-weight: 600;
  background: var(--color-accent-glow);
  padding: 0.25rem 0.75rem;
  border-radius: 100px;
  color: var(--color-primary);
  margin-bottom: var(--space-sm);
  border: 1px solid rgba(201, 150, 59, 0.2);
}
.project-card__text {
  font-size: 0.9rem;
  color: var(--color-text);
}

/* --- Contact Section --- */
.contact-grid {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: var(--space-xl);
  align-items: start;
}
@media (max-width: 768px) {
  .contact-grid { grid-template-columns: 1fr; }
}

/* --- Contact CTA --- */
.cta-section {
  text-align: center;
  position: relative;
  overflow: hidden;
}
.cta-section::before {
  content: '';
  position: absolute;
  bottom: -40%;
  left: 50%;
  transform: translateX(-50%);
  width: 500px;
  height: 500px;
  background: radial-gradient(circle, var(--color-accent-glow) 0%, transparent 70%);
  border-radius: 50%;
  pointer-events: none;
}
.cta-section h2 {
  font-size: 1.75rem;
  position: relative;
}
.cta-section p {
  font-size: 1.125rem;
  max-width: 600px;
  margin-left: auto;
  margin-right: auto;
  position: relative;
}

/* --- Buttons --- */
.btn {
  display: inline-flex;
  align-items: center;
  gap: 0.4rem;
  font-family: var(--font-body);
  font-size: 0.9rem;
  font-weight: 600;
  padding: 0.75rem 1.5rem;
  border-radius: var(--radius);
  border: none;
  cursor: pointer;
  transition: all var(--transition);
  position: relative;
  overflow: hidden;
}
.btn--primary {
  background: var(--color-primary);
  color: #fff;
  box-shadow: 0 2px 8px rgba(26, 58, 74, 0.2);
}
.btn--primary:hover {
  background: var(--color-primary-light);
  color: #fff;
  box-shadow: 0 4px 16px rgba(26, 58, 74, 0.3);
  transform: translateY(-1px);
}
.btn--secondary {
  background: transparent;
  color: var(--color-primary);
  border: 1.5px solid var(--color-border);
}
.btn--secondary:hover {
  border-color: var(--color-primary);
  background: rgba(26, 58, 74, 0.03);
}

/* --- Footer --- */
.site-footer {
  background: var(--color-primary);
  color: rgba(255,255,255,0.7);
  padding: var(--space-lg) 0;
  font-size: 0.85rem;
}
.site-footer a { color: rgba(255,255,255,0.85); }
.site-footer a:hover { color: var(--color-accent-light); }
.site-footer__inner {
  display: flex;
  justify-content: space-between;
  align-items: center;
  flex-wrap: wrap;
  gap: var(--space-sm);
  max-width: var(--max-width);
  margin: 0 auto;
  padding: 0 var(--space-md);
}
.site-footer__links {
  display: flex;
  gap: var(--space-md);
}

/* --- Utilities --- */
.text-center { text-align: center; }
.text-muted { color: var(--color-text-muted); }
.mt-sm { margin-top: var(--space-sm); }
.mt-md { margin-top: var(--space-md); }
.mt-lg { margin-top: var(--space-lg); }
.mb-lg { margin-bottom: var(--space-lg); }
.visually-hidden {
  position: absolute;
  width: 1px;
  height: 1px;
  overflow: hidden;
  clip: rect(0,0,0,0);
  white-space: nowrap;
}

/* --- Supervision clusters --- */
.supervision-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(260px, 1fr));
  gap: var(--space-md);
}
.supervision-cluster {
  background: var(--color-bg-card);
  border: 1px solid var(--color-border-light);
  border-radius: var(--radius-lg);
  padding: var(--space-md);
  transition: box-shadow var(--transition);
}
.supervision-cluster:hover { box-shadow: var(--shadow-sm); }
.supervision-cluster__title {
  font-size: 0.95rem;
  font-weight: 600;
  color: var(--color-primary);
  margin-bottom: var(--space-xs);
}
.supervision-cluster ul {
  list-style: none;
  font-size: 0.85rem;
  color: var(--color-text-light);
}
.supervision-cluster li {
  padding: 0.15rem 0;
  padding-left: 1rem;
  position: relative;
}
.supervision-cluster li::before {
  content: '\00B7';
  position: absolute;
  left: 0;
  color: var(--color-accent);
  font-weight: 700;
}

/* --- Talk list --- */
.talk-list { list-style: none; }
.talk-item {
  padding: var(--space-sm) 0;
  border-bottom: 1px solid var(--color-border-light);
  display: grid;
  grid-template-columns: 100px 1fr;
  gap: var(--space-sm);
}
.talk-item:last-child { border-bottom: none; }
.talk-item__date {
  font-size: 0.8rem;
  font-weight: 600;
  color: var(--color-accent);
}
.talk-item__title {
  font-size: 0.9rem;
  font-weight: 600;
  color: var(--color-primary);
}
.talk-item__event {
  font-size: 0.8rem;
  color: var(--color-text-muted);
}

@media (max-width: 768px) {
  .talk-item { grid-template-columns: 1fr; }
}

/* --- Page header --- */
.page-header {
  padding: var(--space-xl) 0 var(--space-lg);
  border-bottom: 1px solid var(--color-border-light);
  position: relative;
}
.page-header::after {
  content: '';
  position: absolute;
  bottom: -1px;
  left: 0;
  width: 120px;
  height: 3px;
  background: linear-gradient(90deg, var(--color-accent), transparent);
}
.page-header__title {
  font-size: clamp(1.6rem, 4vw, 2.4rem);
}
.page-header__subtitle {
  font-size: 1rem;
  color: var(--color-text-light);
  margin-top: var(--space-xs);
  max-width: 600px;
}

/* --- Research Focus Grid --- */
.focus-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(240px, 1fr));
  gap: var(--space-md);
}
.focus-item {
  background: var(--color-bg-card);
  border: 1px solid var(--color-border-light);
  border-radius: var(--radius-lg);
  padding: var(--space-md);
  border-left: 3px solid var(--color-accent);
  transition: box-shadow var(--transition), transform var(--transition);
}
.focus-item:hover {
  box-shadow: var(--shadow-sm);
  transform: translateY(-2px);
}
.focus-item__title {
  font-size: 1rem;
  font-weight: 600;
  color: var(--color-primary);
  margin-bottom: var(--space-xs);
}
.focus-item__text {
  font-size: 0.85rem;
  color: var(--color-text-light);
}

/* --- Scroll Animations --- */
@keyframes fadeInUp {
  from {
    opacity: 0;
    transform: translateY(24px);
  }
  to {
    opacity: 1;
    transform: translateY(0);
  }
}

.fade-in {
  opacity: 0;
  transform: translateY(24px);
  transition: opacity 0.6s ease, transform 0.6s ease;
}
.fade-in.is-visible {
  opacity: 1;
  transform: translateY(0);
}

/* --- Decorative Separator --- */
.separator {
  display: flex;
  align-items: center;
  justify-content: center;
  padding: var(--space-sm) 0;
}
.separator::before,
.separator::after {
  content: '';
  flex: 1;
  max-width: 80px;
  height: 1px;
  background: var(--color-border);
}
.separator__dot {
  width: 6px;
  height: 6px;
  border-radius: 50%;
  background: var(--color-accent);
  margin: 0 var(--space-sm);
}

/* --- Responsive refinements --- */
@media (max-width: 480px) {
  .container { padding: 0 var(--space-sm); }
  .section { padding: var(--space-lg) 0; }
  .lecture-previews { grid-template-columns: 1fr; }
  .project-cards { grid-template-columns: 1fr; }
  .focus-grid { grid-template-columns: 1fr; }
}