/* ===================================================
   Nicholas Guardino — Professional Website
   Art Direction: Scientific, authoritative, modern
   Palette: Cool slate/navy with teal accent
   Fonts: Instrument Serif (display) + Satoshi (body)
   =================================================== */

:root {
  /* Type Scale */
  --text-xs:   clamp(0.75rem,  0.7rem  + 0.25vw, 0.875rem);
  --text-sm:   clamp(0.875rem, 0.8rem  + 0.35vw, 1rem);
  --text-base: clamp(1rem,     0.95rem + 0.25vw, 1.125rem);
  --text-lg:   clamp(1.125rem, 1rem    + 0.75vw, 1.5rem);
  --text-xl:   clamp(1.5rem,   1.2rem  + 1.25vw, 2.25rem);
  --text-2xl:  clamp(2rem,     1.2rem  + 2.5vw,  3.5rem);
  --text-3xl:  clamp(2.5rem,   1rem    + 4vw,    5rem);

  /* Spacing */
  --space-1:  0.25rem;
  --space-2:  0.5rem;
  --space-3:  0.75rem;
  --space-4:  1rem;
  --space-5:  1.25rem;
  --space-6:  1.5rem;
  --space-8:  2rem;
  --space-10: 2.5rem;
  --space-12: 3rem;
  --space-16: 4rem;
  --space-20: 5rem;
  --space-24: 6rem;
  --space-32: 8rem;

  /* Fonts */
  --font-display: 'Instrument Serif', 'Georgia', serif;
  --font-body: 'Satoshi', 'Inter', 'Helvetica Neue', sans-serif;

  /* Radius */
  --radius-sm: 0.375rem;
  --radius-md: 0.5rem;
  --radius-lg: 0.75rem;
  --radius-xl: 1rem;
  --radius-full: 9999px;

  /* Transitions */
  --transition-interactive: 180ms cubic-bezier(0.16, 1, 0.3, 1);
  --ease-out: cubic-bezier(0.16, 1, 0.3, 1);

  /* Content widths */
  --content-narrow: 640px;
  --content-default: 960px;
  --content-wide: 1200px;
}

/* ---- Dark Mode (Permanent) ---- */
:root, [data-theme="dark"] {
  --color-bg:             #111110;
  --color-surface:        #1a1a18;
  --color-surface-2:      #212120;
  --color-surface-offset: #1e1e1c;
  --color-divider:        #2a2a28;
  --color-border:         #3a3a37;
  --color-text:           #e0dfdc;
  --color-text-muted:     #8a8984;
  --color-text-faint:     #5c5b58;
  --color-text-inverse:   #111110;
  --color-primary:        #5db8bf;
  --color-primary-hover:  #3a9da5;
  --color-primary-light:  #1e2e2f;
  --color-accent-subtle:  #1a2526;
  --shadow-sm: 0 1px 2px rgba(0,0,0,0.3);
  --shadow-md: 0 4px 12px rgba(0,0,0,0.4);
  --shadow-lg: 0 12px 32px rgba(0,0,0,0.5);
}

/* ==============================
   HEADER
   ============================== */
.header {
  position: sticky;
  top: 0;
  z-index: 100;
  background: oklch(from var(--color-bg) l c h / 0.92);
  backdrop-filter: blur(16px);
  -webkit-backdrop-filter: blur(16px);
  border-bottom: 1px solid var(--color-divider);
  transition: transform 0.3s var(--ease-out), box-shadow 0.3s var(--ease-out);
}
.header--hidden { transform: translateY(-100%); }
.header--scrolled { box-shadow: var(--shadow-sm); }
.header-inner {
  max-width: var(--content-wide);
  margin: 0 auto;
  padding: var(--space-3) var(--space-6);
  display: flex;
  align-items: center;
  justify-content: space-between;
}
.header-name {
  font-family: var(--font-display);
  font-size: var(--text-lg);
  color: var(--color-text);
  text-decoration: none;
  letter-spacing: 0.02em;
}
.header-name:hover { color: var(--color-primary); }
.header-nav {
  display: flex;
  gap: var(--space-6);
}
.nav-link {
  font-size: var(--text-sm);
  font-weight: 500;
  color: var(--color-text-muted);
  text-decoration: none;
  letter-spacing: 0.01em;
  position: relative;
  padding: var(--space-1) 0;
}
.nav-link::after {
  content: '';
  position: absolute;
  bottom: -2px;
  left: 0;
  width: 0;
  height: 2px;
  background: var(--color-primary);
  transition: width 0.3s var(--ease-out);
}
.nav-link:hover { color: var(--color-text); }
.nav-link:hover::after { width: 100%; }

.header-actions { display: flex; align-items: center; gap: var(--space-3); }
.mobile-menu-btn {
  display: none;
  width: 44px;
  height: 44px;
  align-items: center;
  justify-content: center;
  border-radius: var(--radius-md);
  color: var(--color-text);
}
.mobile-menu-btn:hover { background: var(--color-surface-offset); }

.mobile-nav {
  display: none;
  flex-direction: column;
  padding: 0 var(--space-6) var(--space-4);
  border-top: 1px solid var(--color-divider);
}
.mobile-nav.open { display: flex; }
.mobile-nav-link {
  font-size: var(--text-base);
  font-weight: 500;
  color: var(--color-text);
  text-decoration: none;
  padding: var(--space-3) 0;
  border-bottom: 1px solid var(--color-divider);
}
.mobile-nav-link:last-child { border-bottom: none; }
.mobile-nav-link:hover { color: var(--color-primary); }

@media (max-width: 768px) {
  .header-nav { display: none; }
  .mobile-menu-btn { display: flex; }
}

/* ==============================
   LAYOUT
   ============================== */
.container {
  max-width: var(--content-wide);
  margin: 0 auto;
  padding-inline: var(--space-6);
}
.container-narrow { max-width: var(--content-default); }

.section {
  padding: clamp(var(--space-16), 8vw, var(--space-32)) 0;
}
.section-alt {
  background: var(--color-surface-2);
}
.section-dark {
  background: var(--color-primary);
  color: var(--color-text-inverse);
}
.section-dark .section-label { color: rgba(255,255,255,0.7); }
.section-dark .pillar-desc { color: rgba(255,255,255,0.8); }

.section-label {
  font-size: var(--text-xs);
  font-weight: 700;
  text-transform: uppercase;
  letter-spacing: 0.12em;
  color: var(--color-primary);
  margin-bottom: var(--space-3);
}
.section-title {
  font-family: var(--font-display);
  font-size: var(--text-xl);
  color: var(--color-text);
  margin-bottom: var(--space-4);
}
.section-desc {
  font-size: var(--text-base);
  color: var(--color-text-muted);
  margin-bottom: var(--space-8);
  max-width: 60ch;
}
.section-desc a {
  color: var(--color-primary);
  text-decoration: underline;
  text-underline-offset: 3px;
}
.section-desc a:hover { color: var(--color-primary-hover); }

/* ==============================
   HERO
   ============================== */
.hero {
  padding: clamp(var(--space-16), 10vw, var(--space-32)) 0 clamp(var(--space-12), 6vw, var(--space-24));
  overflow: hidden;
}
.hero-inner {
  max-width: var(--content-wide);
  margin: 0 auto;
  padding-inline: var(--space-6);
  display: grid;
  grid-template-columns: 1fr 380px;
  gap: var(--space-12);
  align-items: center;
}
.hero-label {
  font-size: var(--text-xs);
  font-weight: 700;
  text-transform: uppercase;
  letter-spacing: 0.12em;
  color: var(--color-primary);
  margin-bottom: var(--space-4);
}
.hero-title {
  font-family: var(--font-display);
  font-size: var(--text-3xl);
  line-height: 1.05;
  color: var(--color-text);
  margin-bottom: var(--space-6);
}
.hero-subtitle {
  font-size: var(--text-base);
  line-height: 1.7;
  color: var(--color-text-muted);
  max-width: 48ch;
  margin-bottom: var(--space-8);
}
.hero-cta-row {
  display: flex;
  gap: var(--space-4);
  flex-wrap: wrap;
}

.hero-image-wrap {
  position: relative;
  justify-self: center;
}
.hero-image {
  width: 100%;
  max-width: 380px;
  height: auto;
  border-radius: var(--radius-xl);
  object-fit: cover;
  aspect-ratio: 3/4;
}
.hero-image-wrap::before {
  content: '';
  position: absolute;
  top: -12px;
  right: -12px;
  bottom: 12px;
  left: 12px;
  border: 2px solid var(--color-primary);
  border-radius: var(--radius-xl);
  opacity: 0.3;
  z-index: -1;
}

@media (max-width: 900px) {
  .hero-inner {
    grid-template-columns: 1fr;
    text-align: center;
  }
  .hero-subtitle { margin-inline: auto; }
  .hero-cta-row { justify-content: center; }
  .hero-image-wrap { order: -1; }
  .hero-image { max-width: 280px; }
  .hero-image-wrap::before { display: none; }
}

/* ==============================
   BUTTONS
   ============================== */
.btn {
  display: inline-flex;
  align-items: center;
  gap: var(--space-2);
  font-family: var(--font-body);
  font-size: var(--text-sm);
  font-weight: 600;
  letter-spacing: 0.02em;
  padding: var(--space-3) var(--space-6);
  border-radius: var(--radius-md);
  text-decoration: none;
  transition: background var(--transition-interactive),
              color var(--transition-interactive),
              box-shadow var(--transition-interactive),
              transform var(--transition-interactive);
  cursor: pointer;
}
.btn:active { transform: translateY(1px); }
.btn-primary {
  background: var(--color-primary);
  color: #fff;
}
.btn-primary:hover {
  background: var(--color-primary-hover);
  box-shadow: var(--shadow-md);
}
.btn-outline {
  background: transparent;
  color: var(--color-text);
  border: 1px solid var(--color-border);
}
.btn-outline:hover {
  border-color: var(--color-primary);
  color: var(--color-primary);
  background: var(--color-accent-subtle);
}

/* ==============================
   ABOUT
   ============================== */
.about-grid {
  display: grid;
  grid-template-columns: 1fr 280px;
  gap: var(--space-12);
  align-items: start;
}
.about-main p {
  font-size: var(--text-base);
  color: var(--color-text-muted);
  margin-bottom: var(--space-4);
  line-height: 1.7;
}
.about-lead {
  font-size: var(--text-base);
  color: var(--color-text) !important;
  font-weight: 500;
}
.about-sidebar {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: var(--space-4);
}
.stat-card {
  background: var(--color-surface);
  border: 1px solid var(--color-divider);
  border-radius: var(--radius-lg);
  padding: var(--space-5);
  text-align: center;
  display: flex;
  flex-direction: column;
  gap: var(--space-1);
}
.stat-number {
  font-family: var(--font-display);
  font-size: var(--text-xl);
  color: var(--color-primary);
  line-height: 1.1;
}
.stat-label {
  font-size: var(--text-xs);
  color: var(--color-text-muted);
  font-weight: 500;
}

@media (max-width: 768px) {
  .about-grid {
    grid-template-columns: 1fr;
    gap: var(--space-8);
  }
  .about-sidebar {
    grid-template-columns: 1fr 1fr;
  }
}

/* ==============================
   TIMELINE
   ============================== */
.timeline {
  position: relative;
  margin-top: var(--space-10);
  padding-left: var(--space-8);
}
.timeline::before {
  content: '';
  position: absolute;
  top: 0;
  left: 11px;
  bottom: 0;
  width: 2px;
  background: var(--color-divider);
}
.timeline-item {
  position: relative;
  margin-bottom: var(--space-10);
}
.timeline-item:last-child { margin-bottom: 0; }
.timeline-marker {
  position: absolute;
  left: calc(-1 * var(--space-8) + 4px);
  top: 6px;
  width: 16px;
  height: 16px;
  border-radius: var(--radius-full);
  background: var(--color-bg);
  border: 3px solid var(--color-primary);
  z-index: 1;
}
.timeline-content {
  background: var(--color-surface);
  border: 1px solid var(--color-divider);
  border-radius: var(--radius-lg);
  padding: var(--space-6);
}
.timeline-meta {
  display: flex;
  align-items: center;
  gap: var(--space-3);
  margin-bottom: var(--space-3);
  flex-wrap: wrap;
}
.timeline-date {
  font-size: var(--text-xs);
  font-weight: 600;
  color: var(--color-text-muted);
}
.timeline-tag {
  font-size: var(--text-xs);
  font-weight: 600;
  color: var(--color-primary);
  background: var(--color-primary-light);
  padding: 2px var(--space-2);
  border-radius: var(--radius-full);
}
.timeline-title {
  font-family: var(--font-body);
  font-size: var(--text-base);
  font-weight: 700;
  color: var(--color-text);
  margin-bottom: var(--space-1);
}
.timeline-sub {
  font-size: var(--text-sm);
  color: var(--color-primary);
  font-weight: 500;
  margin-bottom: var(--space-3);
}
.timeline-content p:last-child {
  font-size: var(--text-sm);
  color: var(--color-text-muted);
  line-height: 1.6;
}

@media (max-width: 600px) {
  .timeline { padding-left: var(--space-6); }
  .timeline-marker { left: calc(-1 * var(--space-6) + 4px); }
  .timeline::before { left: 11px; }
}

/* ==============================
   EDUCATION
   ============================== */
.edu-grid {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: var(--space-6);
}
.edu-card {
  background: var(--color-surface);
  border: 1px solid var(--color-divider);
  border-radius: var(--radius-lg);
  padding: var(--space-8);
  text-align: center;
}
.edu-icon {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  width: 48px;
  height: 48px;
  border-radius: var(--radius-full);
  background: var(--color-primary-light);
  color: var(--color-primary);
  margin: 0 auto var(--space-4);
}
.edu-icon svg { width: 24px; height: 24px; }
.edu-school {
  font-family: var(--font-display);
  font-size: var(--text-lg);
  color: var(--color-text);
  margin-bottom: var(--space-2);
}
.edu-degree {
  font-size: var(--text-sm);
  color: var(--color-text-muted);
  margin-bottom: var(--space-1);
}
.edu-year {
  font-size: var(--text-xs);
  color: var(--color-text-faint);
  font-weight: 600;
}

@media (max-width: 600px) {
  .edu-grid { grid-template-columns: 1fr; }
}

/* ==============================
   PUBLICATIONS
   ============================== */
.pub-list {
  display: flex;
  flex-direction: column;
  gap: var(--space-1);
}
.pub-item {
  padding: var(--space-5) var(--space-6);
  border-radius: var(--radius-md);
  transition: background var(--transition-interactive);
  border-bottom: 1px solid var(--color-divider);
}
.pub-item:last-child { border-bottom: none; }
.pub-item:hover { background: var(--color-surface); }
.pub-journal {
  display: inline-block;
  font-size: var(--text-xs);
  font-weight: 700;
  color: var(--color-primary);
  text-transform: uppercase;
  letter-spacing: 0.08em;
  margin-bottom: var(--space-2);
}
.pub-title {
  font-family: var(--font-body);
  font-size: var(--text-base);
  font-weight: 600;
  color: var(--color-text);
  margin-bottom: var(--space-2);
  line-height: 1.4;
}
.pub-authors {
  font-size: var(--text-sm);
  color: var(--color-text-muted);
  line-height: 1.5;
}
.pub-authors strong {
  color: var(--color-text);
  font-weight: 600;
}

/* ==============================
   PATENT & LEADERSHIP
   ============================== */
.pl-grid {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: var(--space-6);
}
.pl-card {
  background: var(--color-surface);
  border: 1px solid var(--color-divider);
  border-radius: var(--radius-lg);
  padding: var(--space-8);
}
.pl-icon {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  width: 48px;
  height: 48px;
  border-radius: var(--radius-full);
  background: var(--color-primary-light);
  color: var(--color-primary);
  margin-bottom: var(--space-4);
}
.pl-icon svg { width: 24px; height: 24px; }
.pl-title {
  font-family: var(--font-display);
  font-size: var(--text-lg);
  color: var(--color-text);
  margin-bottom: var(--space-3);
}
.pl-desc {
  font-size: var(--text-sm);
  color: var(--color-text-muted);
  line-height: 1.6;
  margin-bottom: var(--space-2);
}
.pl-note {
  font-size: var(--text-xs);
  color: var(--color-primary);
  font-weight: 600;
}

@media (max-width: 600px) {
  .pl-grid { grid-template-columns: 1fr; }
}

/* ==============================
   VISION / GOALS
   ============================== */
.section-dark .section-title { color: #fff; }
.vision-content {
  max-width: 65ch;
  margin-bottom: var(--space-12);
}
.vision-text {
  font-size: var(--text-base);
  color: rgba(255,255,255,0.88);
  line-height: 1.7;
  margin-bottom: var(--space-4);
}
.vision-pillars {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: var(--space-6);
}
.pillar {
  padding: var(--space-6);
  background: rgba(255,255,255,0.08);
  border: 1px solid rgba(255,255,255,0.15);
  border-radius: var(--radius-lg);
}
.pillar-icon {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  width: 44px;
  height: 44px;
  border-radius: var(--radius-full);
  background: rgba(255,255,255,0.12);
  color: #fff;
  margin-bottom: var(--space-4);
}
.pillar-icon svg { width: 22px; height: 22px; }
.pillar-title {
  font-family: var(--font-display);
  font-size: var(--text-lg);
  color: #fff;
  margin-bottom: var(--space-2);
}
.pillar-desc {
  font-size: var(--text-sm);
  color: rgba(255,255,255,0.75);
  line-height: 1.6;
}

@media (max-width: 600px) {
  .vision-pillars { grid-template-columns: 1fr; }
}

/* ==============================
   CONTACT
   ============================== */
.contact-links {
  display: flex;
  gap: var(--space-4);
  flex-wrap: wrap;
  margin-top: var(--space-4);
}
.contact-card {
  display: flex;
  align-items: center;
  gap: var(--space-3);
  background: var(--color-surface);
  border: 1px solid var(--color-divider);
  border-radius: var(--radius-lg);
  padding: var(--space-4) var(--space-6);
  text-decoration: none;
  color: var(--color-text);
  font-size: var(--text-sm);
  font-weight: 500;
  transition: border-color var(--transition-interactive),
              box-shadow var(--transition-interactive),
              transform var(--transition-interactive);
}
.contact-card:hover {
  border-color: var(--color-primary);
  box-shadow: var(--shadow-md);
  transform: translateY(-2px);
}
.contact-card:active { transform: translateY(0); }
.contact-card svg { width: 20px; height: 20px; color: var(--color-primary); flex-shrink: 0; }

@media (max-width: 600px) {
  .contact-links { flex-direction: column; }
  .contact-card { width: 100%; }
}

/* ==============================
   FOOTER
   ============================== */
.footer {
  padding: var(--space-8) 0;
  border-top: 1px solid var(--color-divider);
}
.footer .container {
  display: flex;
  justify-content: space-between;
  align-items: center;
  flex-wrap: wrap;
  gap: var(--space-4);
}
.footer-text {
  font-size: var(--text-xs);
  color: var(--color-text-faint);
}
.footer-attr {
  font-size: var(--text-xs);
  color: var(--color-text-faint);
  text-decoration: none;
}
.footer-attr:hover {
  color: var(--color-text-muted);
  text-decoration: underline;
}

/* ==============================
   SCROLL ANIMATIONS
   ============================== */
.fade-in {
  opacity: 1;
}

@supports (animation-timeline: scroll()) {
  .fade-in {
    opacity: 0;
    animation: reveal-fade linear both;
    animation-timeline: view();
    animation-range: entry 0% entry 40%;
  }
}

@keyframes reveal-fade {
  to { opacity: 1; }
}

/* Fallback for browsers without scroll-driven animations */
@supports not (animation-timeline: scroll()) {
  .fade-in {
    opacity: 0;
    transition: opacity 0.6s var(--ease-out);
  }
  .fade-in.visible {
    opacity: 1;
  }
}