/* ============================================================
   Marco Cappelluti — Academic Website
   style.css
   ============================================================ */

/* --- Google Fonts --- */
@import url('https://fonts.googleapis.com/css2?family=Playfair+Display:ital,wght@0,400;0,600;0,700;1,400&family=Inter:wght@300;400;500;600;700&display=swap');

/* --- CSS Custom Properties --- */
:root {
  --bg:          #f4f5f8;
  --bg-alt:      #eaecf2;
  --surface:     #ffffff;
  --border:      #d8dfe9;
  --text:        #0f1117;
  --text-muted:  #505a6e;
  --text-faint:  #8c98ac;
  --accent:      #2c52a0;
  --accent-soft: #e3ebf8;
  --badge-pub:        #2d6a4f;
  --badge-pub-bg:     #d6f2de;
  --badge-review:     #7b5e00;
  --badge-review-bg:  #fef3cd;
  --badge-wp:         #4e4191;
  --badge-wp-bg:      #eae7f8;
  --nav-height:  64px;
  --max-w:       920px;
  --font-serif:  'Playfair Display', Georgia, serif;
  --font-sans:   'Inter', system-ui, sans-serif;
  --radius:      6px;
  --transition:  0.25s ease;
}

[data-theme="dark"] {
  --bg:          #0f1117;
  --bg-alt:      #181c24;
  --surface:     #1e2330;
  --border:      #2a3044;
  --text:        #e8edf8;
  --text-muted:  #8a97b0;
  --text-faint:  #55627a;
  --accent:      #6b9fe0;
  --accent-soft: #172038;
  --badge-pub:        #74c69d;
  --badge-pub-bg:     #1a3828;
  --badge-review:     #f0c14b;
  --badge-review-bg:  #302500;
  --badge-wp:         #b39ddb;
  --badge-wp-bg:      #251e3a;
}

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

html {
  scroll-behavior: smooth;
  scroll-padding-top: calc(var(--nav-height) + 16px);
  font-size: 17px;
}

body {
  font-family: var(--font-sans);
  background-color: var(--bg);
  color: var(--text);
  line-height: 1.7;
  transition: background-color 0.3s ease, color 0.3s ease;
  -webkit-font-smoothing: antialiased;
}

a {
  color: var(--accent);
  text-decoration: none;
  transition: opacity var(--transition);
}
a:hover { opacity: 0.72; text-decoration: underline; }

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

/* --- Navigation --- */
nav {
  position: fixed;
  top: 0; left: 0; right: 0;
  height: var(--nav-height);
  background: var(--bg);
  border-bottom: 1px solid var(--border);
  z-index: 100;
  transition: background-color 0.3s ease, border-color 0.3s ease;
}

.nav-inner {
  max-width: calc(var(--max-w) + 80px);
  margin: 0 auto;
  padding: 0 40px;
  height: 100%;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 24px;
}

.nav-logo {
  font-family: var(--font-serif);
  font-weight: 600;
  font-size: 1rem;
  color: var(--text);
  white-space: nowrap;
  text-decoration: none;
}
.nav-logo:hover { opacity: 0.72; text-decoration: none; }

.nav-links {
  display: flex;
  align-items: center;
  gap: 28px;
  list-style: none;
}

.nav-links a {
  font-size: 0.8rem;
  font-weight: 500;
  letter-spacing: 0.04em;
  text-transform: uppercase;
  color: var(--text-muted);
  text-decoration: none;
  transition: color var(--transition);
}
.nav-links a:hover { color: var(--text); text-decoration: none; opacity: 1; }

.theme-toggle {
  background: none;
  border: 1px solid var(--border);
  border-radius: 20px;
  padding: 5px 12px;
  cursor: pointer;
  font-size: 0.75rem;
  font-family: var(--font-sans);
  color: var(--text-muted);
  display: flex;
  align-items: center;
  gap: 6px;
  transition: border-color var(--transition), color var(--transition);
  white-space: nowrap;
  flex-shrink: 0;
}
.theme-toggle:hover { border-color: var(--text-muted); color: var(--text); }
.theme-toggle .icon { font-size: 0.85rem; }

/* --- Main Layout --- */
main {
  padding-top: var(--nav-height);
}

.section {
  max-width: calc(var(--max-w) + 80px);
  margin: 0 auto;
  padding: 80px 40px;
}

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

.section-label {
  font-family: var(--font-sans);
  font-size: 0.68rem;
  font-weight: 600;
  letter-spacing: 0.16em;
  text-transform: uppercase;
  color: var(--text-faint);
  margin-bottom: 40px;
}

/* --- Hero Section --- */
#hero {
  min-height: calc(100vh - var(--nav-height));
  display: flex;
  align-items: center;
  border-top: none;
}

.hero-grid {
  display: grid;
  grid-template-columns: 1fr auto;
  gap: 48px;
  align-items: center;
  width: 100%;
}

.hero-photo {
  width: 260px;
  height: 260px;
  border-radius: 50%;
  object-fit: cover;
  object-position: center top;
  border: 3px solid var(--border);
  flex-shrink: 0;
  box-shadow: 0 8px 40px rgba(0,0,0,0.12);
}

.hero-photo-placeholder {
  width: 260px;
  height: 260px;
  border-radius: 50%;
  background: var(--bg-alt);
  border: 3px solid var(--border);
  flex-shrink: 0;
  display: flex;
  align-items: center;
  justify-content: center;
  color: var(--text-faint);
  font-size: 0.75rem;
}

.hero-name {
  font-family: var(--font-serif);
  font-size: clamp(2.6rem, 5.5vw, 3.8rem);
  font-weight: 700;
  line-height: 1.05;
  letter-spacing: -0.025em;
  color: var(--text);
  margin-bottom: 16px;
}

.hero-sub {
  font-size: 0.95rem;
  color: var(--text-muted);
  margin-bottom: 24px;
  font-weight: 400;
  line-height: 1.5;
  letter-spacing: 0.01em;
}

.hero-sub span {
  color: var(--text-faint);
  margin: 0 8px;
}

.hero-tagline {
  font-family: var(--font-sans);
  font-size: 1rem;
  font-weight: 400;
  color: var(--text-muted);
  margin-bottom: 14px;
  line-height: 1.78;
  max-width: 600px;
}

.hero-greeting {
  display: block;
  font-weight: 500;
  color: var(--text);
  margin-bottom: 2px;
}

.hero-supervisors {
  font-size: 0.88rem;
  color: var(--text-faint);
  margin-bottom: 32px;
  line-height: 1.6;
  max-width: 600px;
}

.hero-supervisors a {
  color: var(--text-muted);
  text-decoration: none;
  border-bottom: 1px solid var(--border);
  transition: color var(--transition), border-color var(--transition);
}
.hero-supervisors a:hover {
  color: var(--accent);
  border-color: var(--accent);
  opacity: 1;
  text-decoration: none;
}

.hero-links {
  display: flex;
  flex-wrap: wrap;
  gap: 10px;
}

.hero-link {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  font-size: 0.8rem;
  font-weight: 500;
  padding: 7px 16px;
  border: 1px solid var(--border);
  border-radius: 20px;
  color: var(--text-muted);
  text-decoration: none;
  transition: border-color var(--transition), color var(--transition), background var(--transition), box-shadow var(--transition);
}
.hero-link:hover {
  border-color: var(--accent);
  color: var(--accent);
  background: var(--accent-soft);
  box-shadow: 0 2px 8px rgba(44, 82, 160, 0.10);
  opacity: 1;
  text-decoration: none;
}
.hero-link svg { flex-shrink: 0; }

/* --- Research Section --- */
.research-tags {
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
  margin-bottom: 36px;
}

.research-tag {
  font-size: 0.75rem;
  font-weight: 500;
  letter-spacing: 0.03em;
  color: var(--text-muted);
  background: var(--bg-alt);
  border: 1px solid var(--border);
  border-radius: 20px;
  padding: 5px 13px;
}

.thesis-block {
  background: var(--bg-alt);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 20px 24px;
  margin-bottom: 44px;
}

.thesis-label {
  font-size: 0.7rem;
  font-weight: 600;
  letter-spacing: 0.1em;
  text-transform: uppercase;
  color: var(--text-faint);
  margin-bottom: 8px;
}

.thesis-title {
  font-family: var(--font-serif);
  font-size: 1rem;
  font-style: italic;
  line-height: 1.5;
  color: var(--text);
}

.thesis-meta {
  margin-top: 6px;
  font-size: 0.82rem;
  color: var(--text-muted);
}

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

.paper {
  border-top: 1px solid var(--border);
  padding: 28px 0;
}
.paper:last-child { border-bottom: 1px solid var(--border); }

.paper-header {
  display: flex;
  flex-direction: column;
  gap: 10px;
}

.paper-meta-row {
  display: flex;
  align-items: center;
  gap: 10px;
  flex-wrap: wrap;
}

.paper-badge {
  display: inline-block;
  font-size: 0.67rem;
  font-weight: 600;
  letter-spacing: 0.08em;
  text-transform: uppercase;
  padding: 3px 9px;
  border-radius: 20px;
}
.badge-published   { color: var(--badge-pub);    background: var(--badge-pub-bg); }
.badge-review      { color: var(--badge-review); background: var(--badge-review-bg); }
.badge-working     { color: var(--badge-wp);     background: var(--badge-wp-bg); }

.paper-venue {
  font-size: 0.8rem;
  color: var(--text-faint);
  font-style: italic;
}

.paper-title {
  font-family: var(--font-serif);
  font-size: 1.1rem;
  line-height: 1.42;
  color: var(--text);
  font-weight: 600;
  letter-spacing: -0.01em;
}
.paper-title a {
  color: inherit;
  text-decoration: none;
  transition: color var(--transition);
}
.paper-title a:hover { color: var(--accent); text-decoration: none; opacity: 1; }

.paper-authors {
  font-size: 0.85rem;
  color: var(--text-muted);
}

.paper-awards {
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
  margin-top: 4px;
}

.award-tag {
  font-size: 0.75rem;
  color: var(--badge-pub);
  background: var(--badge-pub-bg);
  padding: 2px 8px;
  border-radius: 4px;
  font-weight: 500;
}

.paper-coverage {
  font-size: 0.8rem;
  color: var(--text-faint);
  margin-top: 4px;
}

.paper-coverage strong {
  color: var(--text-muted);
  font-weight: 500;
}

.abstract-toggle {
  background: none;
  border: none;
  padding: 0;
  cursor: pointer;
  font-family: var(--font-sans);
  font-size: 0.8rem;
  font-weight: 500;
  color: var(--accent);
  display: inline-flex;
  align-items: center;
  gap: 5px;
  margin-top: 10px;
  transition: opacity var(--transition);
}
.abstract-toggle:hover { opacity: 0.7; }

.abstract-toggle .chevron {
  display: inline-block;
  transition: transform 0.25s ease;
  font-size: 0.7rem;
}
.abstract-toggle[aria-expanded="true"] .chevron {
  transform: rotate(180deg);
}

.abstract-body {
  overflow: hidden;
  max-height: 0;
  transition: max-height 0.4s ease, opacity 0.3s ease;
  opacity: 0;
}
.abstract-body.open {
  max-height: 1200px;
  opacity: 1;
}

.abstract-text {
  margin-top: 14px;
  font-size: 0.9rem;
  color: var(--text-muted);
  line-height: 1.75;
  padding-left: 16px;
  border-left: 2px solid var(--border);
}

/* --- About Section --- */
.about-text p {
  font-size: 1rem;
  color: var(--text-muted);
  line-height: 1.8;
  max-width: 640px;
}
.about-text p + p { margin-top: 18px; }

.reviewer-note {
  margin-top: 28px;
}

.reviewer-label {
  font-size: 0.7rem;
  font-weight: 600;
  letter-spacing: 0.1em;
  text-transform: uppercase;
  color: var(--text-faint);
  margin-bottom: 8px;
}

.reviewer-list {
  font-size: 0.88rem;
  color: var(--text-muted);
  line-height: 1.7;
  font-style: italic;
}

/* --- Teaching Section --- */
.teaching-block {
  margin-bottom: 32px;
}

.teaching-institution {
  font-family: var(--font-serif);
  font-size: 1.05rem;
  font-weight: 600;
  color: var(--text);
  margin-bottom: 16px;
}

.course-list {
  list-style: none;
  display: flex;
  flex-direction: column;
  gap: 12px;
}

.course-item {
  display: flex;
  flex-direction: column;
  gap: 2px;
}

.course-code {
  font-size: 0.82rem;
  font-weight: 600;
  font-family: var(--font-sans);
  color: var(--accent);
  letter-spacing: 0.03em;
}

.course-name {
  font-size: 0.95rem;
  color: var(--text);
}

.course-years {
  font-size: 0.8rem;
  color: var(--text-faint);
}

/* --- CV Section --- */
#cv {
  text-align: center;
  padding-top: 60px;
  padding-bottom: 60px;
}

.cv-inner {
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 20px;
}

.cv-label-text {
  font-family: var(--font-serif);
  font-size: 1.2rem;
  color: var(--text-muted);
  font-style: italic;
}

.cv-btn {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  padding: 12px 28px;
  background: var(--accent);
  color: #fff;
  border-radius: 4px;
  font-size: 0.88rem;
  font-weight: 500;
  text-decoration: none;
  transition: opacity var(--transition);
}
.cv-btn:hover { opacity: 0.85; text-decoration: none; color: #fff; }

/* --- Contact Section --- */
.contact-email {
  font-family: var(--font-serif);
  font-size: 1.4rem;
  font-weight: 600;
  color: var(--text);
  text-decoration: none;
  border-bottom: 2px solid var(--border);
  transition: border-color var(--transition), color var(--transition);
  padding-bottom: 2px;
}
.contact-email:hover {
  border-color: var(--accent);
  color: var(--accent);
  opacity: 1;
  text-decoration: none;
}

.contact-sub {
  margin-top: 16px;
  font-size: 0.88rem;
  color: var(--text-faint);
}

/* --- Footer --- */
footer {
  border-top: 1px solid var(--border);
  padding: 28px 40px;
  text-align: center;
  font-size: 0.75rem;
  color: var(--text-faint);
}

/* --- Scroll Animations --- */
.fade-in {
  opacity: 0;
  transform: translateY(22px);
  transition: opacity 0.55s ease, transform 0.55s ease;
}
.fade-in.visible {
  opacity: 1;
  transform: translateY(0);
}

/* stagger children */
.fade-in.delay-1 { transition-delay: 0.08s; }
.fade-in.delay-2 { transition-delay: 0.16s; }
.fade-in.delay-3 { transition-delay: 0.24s; }
.fade-in.delay-4 { transition-delay: 0.32s; }

/* --- Responsive --- */
@media (max-width: 700px) {
  .nav-inner { padding: 0 20px; gap: 16px; }

  .nav-links {
    display: none; /* simplified on mobile */
  }

  .section { padding: 56px 20px; }

  .hero-grid {
    grid-template-columns: 1fr;
    grid-template-rows: auto auto;
    gap: 28px;
    text-align: center;
  }

  .hero-photo, .hero-photo-placeholder {
    width: 170px;
    height: 170px;
    margin: 0 auto;
  }

  .hero-tagline { margin-left: auto; margin-right: auto; }

  .hero-links { justify-content: center; }

  .hero-name { font-size: 2.1rem; }

  footer { padding: 24px 20px; }
}

@media (max-width: 480px) {
  .hero-name { font-size: 1.8rem; }
  .paper-title { font-size: 1rem; }
}