:root {
  color-scheme: light;
  --bg-body: #f7f8fc;
  --bg-hero: linear-gradient(135deg, #e7f2ff 0%, #ede9ff 100%);
  --bg-footer: linear-gradient(135deg, #e9e5ff 0%, #dfeeff 100%);
  --text-default: #0f1b2d;
  --text-muted: #4a5568;
  --lavender: #c8c6ff;
  --navy: #1f2a44;
  --shadow-frame: 0 24px 48px rgba(33, 44, 77, 0.16);
}

* {
  box-sizing: border-box;
}

body {
  margin: 0;
  font-family: "Inter", "Segoe UI", system-ui, -apple-system, BlinkMacSystemFont,
    sans-serif;
  background: var(--bg-body);
  color: var(--text-default);
  line-height: 1.6;
}

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

.skip-link {
  position: absolute;
  left: -999px;
  top: auto;
  padding: 0.5rem 1rem;
  background: var(--navy);
  color: #fff;
  border-radius: 999px;
  z-index: 1000;
}

.skip-link:focus {
  left: 1rem;
  top: 1rem;
}

.container {
  width: min(1200px, calc(100% - 48px));
  margin: 0 auto;
}

.site-header {
  position: sticky;
  top: 0;
  background: rgba(255, 255, 255, 0.95);
  backdrop-filter: blur(12px);
  box-shadow: 0 10px 30px rgba(15, 27, 45, 0.05);
  z-index: 10;
}

.site-header .container {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 1rem 0;
  gap: 1rem;
}

.logo {
  font-weight: 600;
}

.nav {
  display: flex;
  gap: 1rem;
  flex-wrap: wrap;
}

.nav a {
  color: var(--text-muted);
  text-decoration: none;
  font-size: 0.95rem;
}

.nav a.active {
  color: var(--navy);
  font-weight: 600;
}

.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  padding: 0.65rem 1.4rem;
  border-radius: 999px;
  border: 1px solid transparent;
  text-decoration: none;
  font-weight: 600;
  transition: transform 0.2s ease, box-shadow 0.2s ease;
}

.btn:hover {
  transform: translateY(-1px);
}

/* CTA ripple */
.btn {
  position: relative;
  overflow: hidden;
}
.btn .ripple {
  position: absolute;
  border-radius: 50%;
  transform: scale(0);
  background: rgba(255, 255, 255, 0.35);
  animation: ripple 400ms linear;
  pointer-events: none;
}
@keyframes ripple {
  to {
    transform: scale(6);
    opacity: 0;
  }
}

.btn.primary {
  background: var(--navy);
  color: #fff;
}

.btn.secondary {
  background: #fff;
  color: var(--navy);
  border-color: var(--lavender);
}

.btn.outline {
  border-color: var(--navy);
  color: var(--navy);
  background: transparent;
}

.btn.ghost {
  border-color: rgba(31, 42, 68, 0.25);
  color: var(--navy);
  background: transparent;
}

.hero {
  background: var(--bg-hero);
  padding: 5rem 0 4rem;
}

.hero {
  background: linear-gradient(
    135deg,
    #e7f2ff 0%,
    #ede9ff 25%,
    #e8f7ff 75%,
    #ede9ff 100%
  );
  background-size: 200% 200%;
  animation: none;
}

.hero__grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
  gap: 2.5rem;
  align-items: center;
}

.hero {
  position: relative; /* stacking context for hero background */
  overflow: hidden;
}
.hero .container {
  position: relative; /* ensure hero content sits above background */
  z-index: 1;
}

/* Respect reduced motion preference */
@media (prefers-reduced-motion: reduce) {
  .hero {
    animation: none;
  }
}

/* Reduced motion preferences: minimize cost on focus/hover animations */
@media (prefers-reduced-motion: reduce) {
  .btn {
    transition: none !important;
  }
  .btn .ripple {
    display: none !important;
  }
  .reveal {
    transition: none !important;
    opacity: 1 !important;
    transform: none !important;
  }
}

.eyebrow {
  text-transform: uppercase;
  letter-spacing: 0.08em;
  font-size: 0.8rem;
  color: var(--text-muted);
}

h1 {
  font-size: clamp(2.5rem, 4vw, 3.5rem);
  margin-bottom: 0.5rem;
}

.lead {
  font-size: 1.1rem;
  margin-bottom: 1.5rem;
}

.hero__badges {
  display: flex;
  gap: 0.75rem;
  flex-wrap: wrap;
  margin-bottom: 1.5rem;
}

.hero__badges span {
  border: 1px solid rgba(31, 42, 68, 0.2);
  border-radius: 999px;
  padding: 0.5rem 0.9rem;
  font-size: 0.9rem;
  background: #fff;
}

/* Badge shimmer */
.hero__badges span:hover {
  position: relative;
  overflow: hidden;
}
@keyframes shimmer {
  0% {
    background-position: -200% 0;
  }
  100% {
    background-position: 200% 0;
  }
}
.hero__badges span::after {
  content: "";
  position: absolute;
  inset: 0;
  background: linear-gradient(
    90deg,
    rgba(255, 255, 255, 0) 0%,
    rgba(255, 255, 255, 0.5) 50%,
    rgba(255, 255, 255, 0) 100%
  );
  background-size: 200% 200%;
  animation: none;
  opacity: 0;
}
.hero__badges span:hover::after {
  opacity: 1;
  animation: shimmer 1.2s linear forwards;
}

.cta-row {
  display: flex;
  flex-wrap: wrap;
  gap: 0.75rem;
  margin-bottom: 1rem;
}

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

.quote-card {
  background: #fff;
  padding: 2rem;
  border-radius: 24px;
  box-shadow: 0 30px 80px rgba(15, 27, 45, 0.07);
}

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

section {
  padding: 4rem 0;
}

.section-heading {
  margin-bottom: 2rem;
}

.timeline {
  background: #fff;
}

.timeline__grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(220px, 1fr));
  gap: 1.5rem;
}

.timeline__grid article {
  border: 1px solid rgba(31, 42, 68, 0.08);
  border-radius: 24px;
  padding: 1.5rem;
  background: linear-gradient(135deg, #f9faff 0%, #f3f6ff 100%);
}

/* reveal animation for timeline and other sections */
.reveal {
  opacity: 0;
  transform: translateY(20px);
  transition: opacity 500ms ease, transform 500ms ease;
}
.reveal.is-visible {
  opacity: 1;
  transform: translateY(0);
}

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

.projects__grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(320px, 1fr));
  gap: 2rem;
}

.project-card {
  background: #fff;
  border-radius: 32px;
  padding: 1.75rem;
  display: flex;
  flex-direction: column;
  gap: 1.25rem;
  box-shadow: 0 30px 80px rgba(15, 27, 45, 0.05);
}
.project-card:hover {
  box-shadow: 0 40px 120px rgba(15, 27, 45, 0.08);
}

/* reveal animation for project cards — reveal strictly one-by-one (sequential) */
.project-card {
  opacity: 0;
  transform: translateY(20px) scale(0.996);
  transition: opacity 500ms ease, transform 500ms ease;
}
.project-card.is-visible {
  opacity: 1;
  transform: translateY(0) scale(1);
}

@media (prefers-reduced-motion: reduce) {
  .project-card {
    transition: none !important;
    transform: none !important;
    opacity: 1 !important;
  }
}

.project-card__media-link {
  display: block;
  text-decoration: none;
}

.project-card__media-link:focus-visible {
  outline: 2px solid var(--navy);
  border-radius: 28px;
  outline-offset: 6px;
}

.project-card__media {
  position: relative;
  padding-top: 56.25%;
  border-radius: 24px;
  overflow: hidden;
  border: 2px solid rgba(200, 198, 255, 0.95);
  box-shadow: var(--shadow-frame);
  background: linear-gradient(135deg, #edf1ff 0%, #f5ecff 100%);
}

/* Project type label */
.project__type {
  display: inline-block;
  font-size: 0.8rem;
  color: var(--navy);
  background: #f6f5ff;
  border: 1px solid rgba(200, 198, 255, 0.5);
  padding: 0.25rem 0.6rem;
  border-radius: 999px;
  margin-left: 0.5rem;
  font-weight: 600;
}
.project__type--prod {
  background: linear-gradient(90deg, #e6f5ff, #eef3ff);
  color: var(--navy);
}
.project__type--academic {
  background: linear-gradient(90deg, #fffaf8, #fffaf8);
  color: var(--text-muted);
}

.project-card__media img {
  position: absolute;
  inset: 0;
  width: 100%;
  height: 100%;
  object-fit: cover;
  transition: transform 300ms cubic-bezier(0.2, 0.8, 0.2, 1);
}
.project-card__media img.is-loaded {
  opacity: 1;
}
.project-card__media img.is-fallback {
  filter: saturate(0.6) contrast(1.02);
  opacity: 0.95;
}
.project-card__media img {
  transition: opacity 300ms ease, transform 300ms cubic-bezier(0.2, 0.8, 0.2, 1);
  opacity: 0;
}
.project-card__media img.is-loaded {
  opacity: 1;
}

/* screenshot hover parallax */
.project-card:hover .project-card__media img {
  transform: translateY(-3px) scale(1.01);
  transition: transform 200ms cubic-bezier(0.2, 0.8, 0.2, 1);
}

.project-card ul {
  padding-left: 1.2rem;
  margin: 0;
}

.badge-row {
  display: flex;
  flex-wrap: wrap;
  gap: 0.5rem;
}

.badge-row span {
  font-size: 0.85rem;
  padding: 0.35rem 0.8rem;
  border-radius: 999px;
  background: #f5f4ff;
  color: var(--navy);
}

.skills {
  background: #fff;
}

.skills__grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(240px, 1fr));
  gap: 1.5rem;
}

.skill-card {
  border-radius: 28px;
  padding: 1.75rem 1.6rem;
  background: linear-gradient(135deg, #fdfdff 0%, #f4f5ff 100%);
  border: 1px solid rgba(31, 42, 68, 0.08);
  position: relative;
  overflow: hidden;
  min-height: 180px;
}

/* skill card pop on scroll */
.skill-card {
  opacity: 0;
  transform: translateY(10px) scale(0.996);
  transition: opacity 500ms ease, transform 500ms ease;
}
.skill-card.is-visible {
  opacity: 1;
  transform: translateY(0) scale(1);
}

.skill-card__header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 0.75rem;
  margin-bottom: 0.75rem;
}

.skill-card h3 {
  margin: 0;
}

.skill-card__level {
  background: rgba(200, 198, 255, 0.2);
  border: 1px solid rgba(200, 198, 255, 0.6);
  border-radius: 999px;
  padding: 0.2rem 0.85rem;
  font-size: 0.8rem;
  font-weight: 600;
  color: var(--navy);
  letter-spacing: 0.02em;
}
.skill-card__level {
  transition: transform 300ms cubic-bezier(0.2, 0.8, 0.2, 1);
}
.skill-card.is-visible .skill-card__level {
  transform: scale(1.05);
}
.skill-card__level {
  letter-spacing: 0.02em;
}

.contact {
  background: var(--bg-hero);
}

.contact__grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
  gap: 2rem;
  align-items: center;
}

.contact__card {
  background: #fff;
  border-radius: 32px;
  padding: 2rem;
  box-shadow: 0 25px 60px rgba(15, 27, 45, 0.08);
}

.site-footer {
  background: var(--bg-footer);
  padding: 1.5rem 0;
  text-align: center;
}

/* progress bar */
#progress {
  height: 4px;
  background: linear-gradient(90deg, #b7c9ff, #e6f5ff);
  position: fixed;
  top: 0;
  left: 0;
  width: 0%;
  z-index: 9999;
}

@media (max-width: 768px) {
  .site-header .container {
    flex-direction: column;
  }

  .nav {
    justify-content: center;
  }
}