/* =========================================================
   Tokens
   ========================================================= */
:root {
  --bg: #FFFFFF;
  --bg-subtle: #F4F7FC;
  --text: #1A1A1A;
  --text-muted: #5C5C5C;
  --border: #E1E7F0;
  --accent: #5B9BF5;
  --accent-hover: #3478E0;
  --accent-soft: #DDE9FB;
  --hero-overlay: rgba(20, 32, 60, 0.55);

  --font-sans: "Inter", -apple-system, BlinkMacSystemFont, "Segoe UI", system-ui, sans-serif;
  --font-mono: "JetBrains Mono", "SF Mono", ui-monospace, "Menlo", monospace;

  --content-narrow: 820px;
  --content-wide: 1100px;

  --radius-sm: 4px;
  --radius-md: 6px;
  --radius-lg: 8px;
}

/* =========================================================
   Reset & base
   ========================================================= */
*, *::before, *::after { box-sizing: border-box; }

html { scroll-behavior: smooth; }

body {
  margin: 0;
  font-family: var(--font-sans);
  font-weight: 400;
  font-size: 16px;
  line-height: 1.6;
  color: var(--text);
  background-color: #DDE9FB;
  position: relative;
  -webkit-font-smoothing: antialiased;
  text-rendering: optimizeLegibility;
}
body::before {
  content: '';
  position: fixed;
  inset: 0;
  z-index: -1;
  background-image:
    linear-gradient(rgba(221, 233, 251, 0.55), rgba(208, 224, 246, 0.55)),
    url('assets/sf.jpg');
  background-size: cover;
  background-position: center;
  filter: blur(60px);
  transform: scale(1.2);
  pointer-events: none;
}

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

a {
  color: var(--accent);
  text-decoration: none;
}
a:hover { text-decoration: underline; }
a:focus-visible {
  outline: 2px solid var(--accent);
  outline-offset: 2px;
  border-radius: 2px;
}

h1, h2, h3 {
  font-weight: 600;
  letter-spacing: -0.01em;
  line-height: 1.2;
  margin: 0 0 16px;
}

h1 { font-size: 3rem; letter-spacing: -0.02em; }
h2 { font-size: 1.75rem; }
h3 { font-size: 1.125rem; }

p { margin: 0 0 16px; }

/* =========================================================
   Skip link
   ========================================================= */

/* =========================================================
   Nav
   ========================================================= */
.nav {
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  z-index: 50;
  background: rgba(245, 250, 255, 0.62);
  backdrop-filter: blur(16px) saturate(180%);
  -webkit-backdrop-filter: blur(16px) saturate(180%);
  border-bottom: 1px solid rgba(91, 155, 245, 0.15);
  transition: background 0.25s ease, border-color 0.25s ease;
}
.nav--scrolled {
  background: rgba(245, 250, 255, 0.72);
  backdrop-filter: blur(28px) saturate(200%);
  -webkit-backdrop-filter: blur(28px) saturate(200%);
  border-bottom-color: rgba(91, 155, 245, 0.25);
}

.nav__inner {
  max-width: var(--content-wide);
  margin: 0 auto;
  height: 64px;
  padding: 0 24px;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 16px;
}

.nav__brand {
  font-weight: 600;
  color: var(--text);
  font-size: 1rem;
}
.nav__brand:hover { text-decoration: none; color: var(--text); }

.nav__links {
  list-style: none;
  margin: 0;
  padding: 0;
  display: flex;
  gap: 24px;
  align-items: center;
  flex-wrap: wrap;
}

.nav__link {
  color: var(--text);
  font-size: 0.9375rem;
  padding: 4px 0;
  border-bottom: 2px solid transparent;
  transition: color 0.25s ease, border-color 0.25s ease;
}
.nav__link:hover { text-decoration: none; color: var(--accent); }
.nav__link--active {
  color: var(--accent);
  border-bottom-color: var(--accent);
}

/* Hamburger toggle — hidden on desktop, shown on small screens */
.nav__toggle {
  display: none;
  flex-direction: column;
  justify-content: center;
  gap: 5px;
  width: 40px;
  height: 40px;
  padding: 8px;
  margin: 0;
  background: none;
  border: 0;
  cursor: pointer;
}
.nav__toggle-bar {
  display: block;
  width: 100%;
  height: 2px;
  background: var(--text);
  border-radius: 2px;
  transition: transform 0.25s ease, opacity 0.25s ease;
}
.nav--open .nav__toggle-bar:nth-child(1) {
  transform: translateY(7px) rotate(45deg);
}
.nav--open .nav__toggle-bar:nth-child(2) {
  opacity: 0;
}
.nav--open .nav__toggle-bar:nth-child(3) {
  transform: translateY(-7px) rotate(-45deg);
}

/* =========================================================
   Layout containers
   ========================================================= */
.container {
  max-width: var(--content-narrow);
  margin: 0 auto;
  padding: 0 24px;
}

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

main { padding-bottom: 0; }

section {
  padding: 80px 0;
  scroll-margin-top: 64px;
}
.projects-section { padding-bottom: 96px; }
.education { padding-top: 96px; }
.projects__other { padding-bottom: 8px; }
.projects-group:last-child .project-mini:last-child {
  padding-bottom: 8px;
}

/* =========================================================
   Hero
   ========================================================= */
.hero {
  position: relative;
  min-height: 80vh;
  padding: 0;
  display: flex;
  align-items: center;
  justify-content: center;
  text-align: center;
  background-image:
    linear-gradient(var(--hero-overlay), var(--hero-overlay)),
    url('assets/sf.jpg');
  background-size: cover;
  background-position: center;
  color: #FFFFFF;
  scroll-margin-top: 0;
}
.hero .container {
  width: 100%;
  padding-top: 64px;
  padding-bottom: 64px;
  display: flex;
  flex-direction: column;
  align-items: center;
}
.hero__positioning {
  margin-left: auto;
  margin-right: auto;
}
.hero .social {
  justify-content: center;
}
.hero__name {
  font-size: 3.5rem;
  margin: 0 0 12px;
  color: #FFFFFF;
  letter-spacing: -0.02em;
}
.hero__positioning {
  font-size: 1.25rem;
  color: rgba(255, 255, 255, 0.88);
  margin: 0 0 32px;
}
.hero .social a {
  color: #FFFFFF;
  border-bottom-color: rgba(255, 255, 255, 0.4);
}
.hero .social a:hover {
  color: var(--accent);
  border-bottom-color: var(--accent);
}

/* =========================================================
   Buttons & social row
   ========================================================= */
.btn {
  display: inline-block;
  padding: 10px 20px;
  border-radius: var(--radius-md);
  font-size: 0.9375rem;
  font-weight: 500;
  border: 1px solid transparent;
  cursor: pointer;
  transition: background 0.15s, color 0.15s, border-color 0.15s;
}
.btn:hover { text-decoration: none; }

.btn--solid {
  background: var(--text);
  color: var(--bg);
  border-color: var(--text);
}
.btn--solid:hover { background: #000; border-color: #000; color: var(--bg); }

.btn--ghost {
  background: transparent;
  color: var(--text);
  border-color: var(--border);
}
.btn--ghost:hover { background: var(--bg-subtle); color: var(--text); }

.social {
  display: flex;
  flex-wrap: wrap;
  gap: 8px 20px;
  font-size: 0.9375rem;
}
.social a { color: var(--text); border-bottom: 1px solid var(--border); padding-bottom: 1px; }
.social a:hover { text-decoration: none; color: var(--accent); border-bottom-color: var(--accent); }

/* =========================================================
   Shared section dividers + section title
   ========================================================= */
.about,
.projects-section,
.education,
.skills,
.contact {
  border-top: 1px solid rgba(91, 155, 245, 0.16);
}

.section__title {
  margin-bottom: 32px;
  color: var(--accent);
}

/* =========================================================
   About - portrait + text
   ========================================================= */
.about__inner {
  display: grid;
  grid-template-columns: 340px 1fr;
  gap: 72px;
  align-items: center;
}
.about__portrait {
  margin: 0;
}
.about__portrait img {
  width: 340px;
  height: 340px;
  object-fit: cover;
  background: var(--bg-subtle);
  border: 1px solid var(--border);
  border-radius: 50%;
  box-shadow: 0 12px 32px rgba(20, 32, 60, 0.10);
}
.about__text p {
  font-size: 1.0625rem;
  line-height: 1.7;
  max-width: 620px;
}
.about__text p:last-child {
  margin-bottom: 0;
}

/* =========================================================
   Education
   ========================================================= */
.education__card {
  max-width: 640px;
}
.education__card + .education__card {
  margin-top: 32px;
  padding-top: 32px;
  border-top: 1px solid rgba(91, 155, 245, 0.18);
}
.education__school {
  margin: 0 0 4px;
  font-size: 1.25rem;
}
.education__line {
  margin: 0;
  font-size: 1rem;
}
.education__line.muted {
  color: var(--text-muted);
  font-size: 0.9375rem;
  margin-bottom: 16px;
}
.education__details {
  margin: 16px 0 0;
  display: grid;
  grid-template-columns: 140px 1fr;
  gap: 8px 24px;
  font-size: 0.9375rem;
}
.education__details dt {
  font-weight: 500;
  color: var(--text-muted);
  margin: 0;
}
.education__details dd {
  margin: 0;
}

/* =========================================================
   Skills
   ========================================================= */
.skills__group {
  display: grid;
  grid-template-columns: 200px 1fr;
  gap: 16px 32px;
  align-items: baseline;
  padding: 16px 0;
  border-bottom: 1px solid var(--border);
}
.skills__group:last-child {
  border-bottom: none;
}
.skills__category {
  margin: 0;
  font-size: 1rem;
  color: var(--text-muted);
  font-weight: 500;
}

/* =========================================================
   Contact section
   ========================================================= */
.contact p {
  font-size: 1.0625rem;
  max-width: 640px;
  color: var(--text-muted);
}
.contact__list {
  list-style: none;
  padding: 0;
  margin: 24px 0 0;
  display: flex;
  flex-direction: column;
  gap: 8px;
  font-size: 1.0625rem;
}
.contact__list a {
  color: var(--text);
  border-bottom: 1px solid var(--border);
  padding: 2px 0;
  display: inline-block;
}
.contact__list a:hover {
  color: var(--accent);
  border-bottom-color: var(--accent);
  text-decoration: none;
}

/* =========================================================
   Projects section - Niki featured + compact list
   ========================================================= */
.projects {
  display: flex;
  flex-direction: column;
  gap: 96px;
}

/* Featured project (Niki) - image stacked above text */
.project-featured {
  display: flex;
  flex-direction: column;
  gap: 40px;
  scroll-margin-top: 96px;
  margin-bottom: 24px;
}
.project-featured__media { margin: 0; }
.project-featured__media img {
  width: 100%;
  height: auto;
  display: block;
  background: var(--bg-subtle);
  border: 1px solid var(--border);
  border-radius: var(--radius-lg);
  box-shadow: 0 16px 40px rgba(20, 32, 60, 0.12);
}
.project-featured__body {
  max-width: 820px;
}
.project-featured__badge {
  display: inline-block;
  font-family: var(--font-mono);
  font-size: 0.75rem;
  letter-spacing: 0.12em;
  text-transform: uppercase;
  color: var(--accent);
  margin-bottom: 16px;
}
.project-featured__title {
  font-size: 2.25rem;
  margin: 0 0 8px;
  letter-spacing: -0.015em;
  line-height: 1.15;
}
.project-featured__meta {
  font-size: 1rem;
  color: var(--text-muted);
  margin: 0 0 20px;
}
.project-featured__desc {
  font-size: 1.0625rem;
  line-height: 1.7;
  margin: 0 0 20px;
}
.project-featured__body .tags {
  margin-bottom: 20px;
}
.project-featured__links {
  display: flex;
  flex-wrap: wrap;
  gap: 4px 24px;
  margin: 0;
  font-size: 1rem;
}

/* Compact list of "other" projects */
.projects__other {
  margin-top: 16px;
}
.projects-group + .projects-group {
  margin-top: 56px;
}
.projects-group__heading {
  font-family: var(--font-mono);
  font-size: 0.8125rem;
  letter-spacing: 0.1em;
  text-transform: uppercase;
  color: var(--text-muted);
  font-weight: 500;
  margin: 0 0 8px;
  padding-bottom: 8px;
  border-bottom: 1px solid rgba(91, 155, 245, 0.3);
}
.project-mini-list {
  list-style: none;
  margin: 0;
  padding: 0;
}
.project-mini {
  padding: 24px 0;
  border-bottom: 1px solid rgba(91, 155, 245, 0.18);
}
.project-mini:last-child { border-bottom: none; }
.project-mini__head {
  display: flex;
  flex-wrap: wrap;
  gap: 4px 16px;
  align-items: baseline;
  margin-bottom: 6px;
}
.project-mini__title {
  font-size: 1.125rem;
  margin: 0;
  letter-spacing: -0.005em;
}
.project-mini__meta {
  font-size: 0.875rem;
  color: var(--text-muted);
}
.project-mini__desc {
  font-size: 0.9375rem;
  margin: 0 0 10px;
  max-width: 720px;
}
.project-mini__foot {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 12px 24px;
}
.project-mini__foot .tags { margin: 0; }
.project-mini__links {
  margin: 0;
  font-size: 0.875rem;
}

.project {
  display: grid;
  grid-template-columns: minmax(320px, 420px) 1fr;
  gap: 48px;
  align-items: start;
  scroll-margin-top: 96px;
}

.project__media {
  margin: 0;
}
.project__media img {
  width: 100%;
  aspect-ratio: 4 / 3;
  object-fit: cover;
  background: var(--bg-subtle);
  border: 1px solid var(--border);
  border-radius: var(--radius-lg);
}

.project__title {
  font-size: 1.75rem;
  margin: 0 0 6px;
}
.project__meta {
  font-size: 0.875rem;
  color: var(--text-muted);
  margin: 0 0 16px;
}
.project__desc {
  font-size: 1rem;
  margin: 0 0 16px;
  color: var(--text);
}

.tags {
  list-style: none;
  margin: 0 0 16px;
  padding: 0;
  display: flex;
  flex-wrap: wrap;
  gap: 6px;
}
.tags li {
  font-family: var(--font-mono);
  font-size: 0.75rem;
  letter-spacing: 0.05em;
  text-transform: uppercase;
  background: var(--bg);
  border: 1px solid var(--border);
  border-radius: var(--radius-sm);
  padding: 2px 8px;
  color: var(--text-muted);
}

.project__links {
  display: flex;
  flex-wrap: wrap;
  gap: 4px 20px;
  margin: 0;
  font-size: 0.9375rem;
}
.project__links .muted {
  color: var(--text-muted);
}

/* =========================================================
   Footer
   ========================================================= */
.footer {
  border-top: 1px solid rgba(91, 155, 245, 0.22);
  padding: 32px 0 48px;
  font-size: 0.875rem;
  color: var(--text-muted);
}
.footer__inner {
  display: flex;
  flex-wrap: wrap;
  justify-content: space-between;
  gap: 16px;
}
.footer a { color: var(--text); }
.footer a:hover { color: var(--accent); text-decoration: none; }
.footer__links {
  display: flex;
  flex-wrap: wrap;
  gap: 8px 20px;
}

/* =========================================================
   Responsive
   ========================================================= */
@media (max-width: 880px) {
  .project {
    grid-template-columns: 1fr;
    gap: 24px;
  }
  .project__media img { aspect-ratio: 16 / 10; }
  .project-featured { gap: 28px; }
  .project-featured__title { font-size: 1.75rem; }
  .about__inner {
    grid-template-columns: 1fr;
    gap: 32px;
    justify-items: center;
    text-align: left;
  }
  .about__portrait img {
    width: 240px;
    height: 240px;
  }
  .about__text {
    width: 100%;
  }
  .skills__group {
    grid-template-columns: 1fr;
    gap: 8px;
  }
  .education__details {
    grid-template-columns: 1fr;
    gap: 4px 0;
  }
  .education__details dt {
    margin-top: 8px;
  }
}

@media (max-width: 640px) {
  h1 { font-size: 2.25rem; }
  h2 { font-size: 1.5rem; }
  .hero { min-height: 70vh; }
  .hero__name { font-size: 2.5rem; }
  .hero__positioning { font-size: 1.125rem; margin-bottom: 24px; }
  section { padding: 64px 0; }
  .section__title { margin-bottom: 24px; }
  .projects { gap: 64px; }
  .project__title { font-size: 1.5rem; }
  .nav__inner { padding: 0 16px; }
  .container { padding: 0 16px; }

  .nav__toggle { display: flex; margin-left: auto; }

  .nav__links {
    position: absolute;
    top: 64px;
    left: 0;
    right: 0;
    flex-direction: column;
    align-items: stretch;
    gap: 0;
    padding: 8px 16px 16px;
    background: rgba(245, 250, 255, 0.92);
    backdrop-filter: blur(28px) saturate(200%);
    -webkit-backdrop-filter: blur(28px) saturate(200%);
    border-bottom: 1px solid rgba(91, 155, 245, 0.25);
    font-size: 1rem;

    /* Collapsed by default */
    opacity: 0;
    visibility: hidden;
    transform: translateY(-8px);
    pointer-events: none;
    transition: opacity 0.2s ease, transform 0.2s ease, visibility 0.2s;
  }
  .nav--open .nav__links {
    opacity: 1;
    visibility: visible;
    transform: translateY(0);
    pointer-events: auto;
  }
  .nav__link {
    display: block;
    padding: 12px 0;
    border-bottom: 1px solid rgba(91, 155, 245, 0.12);
  }
  .nav__link--active {
    border-bottom-color: var(--accent);
  }
}

/* Reduced motion */
@media (prefers-reduced-motion: reduce) {
  html { scroll-behavior: auto; }
  * { transition-duration: 0.01ms !important; animation-duration: 0.01ms !important; }
}