/* ---------------------------------------------------------
   Design tokens
--------------------------------------------------------- */
:root {
  /* color — cool neutral palette, rust + UofT-blue accents */
  --color-bg: #f2f3f4;
  --color-bg-raised: #e9ebed;
  --color-ink: #1c1f24;
  --color-ink-muted: #5b6169;
  --color-border: #d7dade;
  --color-accent: #b8391a;
  --color-accent-ink: #f2f3f4;
  --color-accent-2: #1e3765;
  --color-accent-2-ink: #f2f3f4;
  --grid-dot: color-mix(in srgb, var(--color-ink) 5%, transparent);
  --ease: cubic-bezier(0.4, 0, 0.2, 1);

  /* type */
  --font-display: 'Fraunces', Georgia, 'Times New Roman', serif;
  --font-body: 'Source Sans 3', -apple-system, BlinkMacSystemFont, 'Segoe UI', sans-serif;

  --step--1: clamp(0.83rem, 0.8rem + 0.15vw, 0.9rem);
  --step-0: clamp(1rem, 0.96rem + 0.2vw, 1.125rem);
  --step-1: clamp(1.2rem, 1.12rem + 0.4vw, 1.4rem);
  --step-2: clamp(1.5rem, 1.35rem + 0.75vw, 1.9rem);
  --step-3: clamp(1.9rem, 1.6rem + 1.4vw, 2.6rem);
  --step-4: clamp(2.8rem, 2rem + 4.5vw, 5.25rem);
  --step-5: clamp(3rem, 2.1rem + 5vw, 5.75rem);

  /* spacing scale (4px base) */
  --space-1: 0.25rem;
  --space-2: 0.5rem;
  --space-3: 0.75rem;
  --space-4: 1rem;
  --space-6: 1.5rem;
  --space-8: 2rem;
  --space-12: 3rem;
  --space-16: 4rem;
  --space-20: 5rem;
  --space-24: 6rem;

  --radius: 3px;
  --content-width: 40rem;
  --page-width: 56rem;
}

@media (prefers-color-scheme: dark) {
  :root {
    --color-bg: #15171a;
    --color-bg-raised: #1d2024;
    --color-ink: #e7e9ec;
    --color-ink-muted: #9aa0a8;
    --color-border: #2e3238;
    --color-accent: #e8794a;
    --color-accent-ink: #15171a;
    --color-accent-2: #7f9bcc;
    --color-accent-2-ink: #15171a;
    --grid-dot: color-mix(in srgb, var(--color-ink) 4.5%, transparent);
  }
}

/* ---------------------------------------------------------
   Reset
--------------------------------------------------------- */
*, *::before, *::after { box-sizing: border-box; }
html { -webkit-text-size-adjust: 100%; }
body, h1, h2, h3, p, dl, dd, ul, figure { margin: 0; }
ul { list-style: none; padding: 0; }
img { max-width: 100%; display: block; }
a { color: inherit; }

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

/* ---------------------------------------------------------
   Base
--------------------------------------------------------- */
html {
  scroll-behavior: smooth;
  scroll-padding-top: var(--space-16);
}

body {
  background-color: var(--color-bg);
  background-image: radial-gradient(circle at 1px 1px, var(--grid-dot) 1px, transparent 0);
  background-size: 24px 24px;
  color: var(--color-ink);
  font-family: var(--font-body);
  font-size: var(--step-0);
  line-height: 1.6;
  -webkit-font-smoothing: antialiased;
}

h1, h2, h3 {
  font-family: var(--font-display);
  font-weight: 700;
  line-height: 1.15;
  letter-spacing: -0.012em;
}

h1 { font-size: var(--step-4); }
h2 { font-size: var(--step-2); }
h3 { font-size: var(--step-1); }

.hero h1 {
  font-size: var(--step-5);
  line-height: 1.05;
  letter-spacing: -0.025em;
}

a {
  text-decoration: none;
}

a:focus-visible,
button:focus-visible {
  outline: 2px solid var(--color-accent);
  outline-offset: 3px;
}

.skip-link {
  position: absolute;
  left: -999px;
  top: 0;
  background: var(--color-accent);
  color: var(--color-accent-ink);
  padding: var(--space-3) var(--space-4);
  z-index: 100;
}
.skip-link:focus {
  left: var(--space-4);
  top: var(--space-4);
}

/* underline-draw link style, used for inline text links */
.text-link {
  background-image: linear-gradient(var(--color-accent), var(--color-accent));
  background-position: 0 100%;
  background-repeat: no-repeat;
  background-size: 0% 1px;
  transition: background-size 0.2s var(--ease);
  padding-bottom: 2px;
}
.text-link:hover,
.text-link:focus-visible {
  background-size: 100% 1px;
}

/* ---------------------------------------------------------
   Floating social sidebar
--------------------------------------------------------- */
.side-social {
  position: fixed;
  left: var(--space-8);
  bottom: 0;
  z-index: 10;
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: var(--space-4);
  padding-bottom: var(--space-6);
}
.side-social a {
  display: flex;
  color: var(--color-ink-muted);
  transition: color 0.15s var(--ease), transform 0.15s var(--ease);
}
.side-social a:hover,
.side-social a:focus-visible {
  color: var(--color-accent);
  transform: translateY(-2px);
}
.side-social-line {
  width: 1px;
  height: 5.5rem;
  background: var(--color-border);
}

@media (max-width: 1199px) {
  .side-social {
    display: none;
  }
}

/* ---------------------------------------------------------
   Layout shell
--------------------------------------------------------- */
main {
  max-width: var(--page-width);
  margin-inline: auto;
  padding-inline: var(--space-6);
}

/* ---------------------------------------------------------
   Scroll reveal (defined early: component hover transforms
   defined later in the cascade must win ties over this)
--------------------------------------------------------- */
.reveal {
  opacity: 0;
  transform: translateY(8px);
  transition: opacity 0.5s ease, transform 0.5s ease;
  transition-delay: calc(var(--reveal-i, 0) * 70ms);
}
.reveal.is-visible {
  opacity: 1;
  transform: none;
}

/* ---------------------------------------------------------
   Header / nav
--------------------------------------------------------- */
.site-header {
  position: sticky;
  top: 0;
  z-index: 50;
  background: var(--color-bg);
  border-bottom: 1px solid transparent;
  transition: background-color 0.2s var(--ease), border-color 0.2s var(--ease);
}
@supports (backdrop-filter: blur(1px)) or (-webkit-backdrop-filter: blur(1px)) {
  .site-header {
    background: color-mix(in srgb, var(--color-bg) 82%, transparent);
    backdrop-filter: blur(10px) saturate(140%);
    -webkit-backdrop-filter: blur(10px) saturate(140%);
  }
}
.site-header.is-scrolled {
  border-bottom-color: var(--color-border);
}

.site-nav {
  max-width: var(--page-width);
  margin-inline: auto;
  padding: var(--space-4) var(--space-6);
  display: flex;
  align-items: center;
  justify-content: space-between;
}

.wordmark {
  font-family: var(--font-display);
  font-weight: 600;
  font-size: var(--step-0);
}

.nav-links {
  display: flex;
  gap: var(--space-6);
  font-size: var(--step--1);
}

.nav-links a {
  position: relative;
  color: var(--color-ink-muted);
  transition: color 0.15s var(--ease);
}
.nav-links a::after {
  content: '';
  position: absolute;
  left: 0;
  right: 0;
  bottom: -3px;
  height: 1px;
  background: var(--color-accent);
  transform: scaleX(0);
  transform-origin: left;
  transition: transform 0.2s var(--ease);
}
.nav-links a:hover,
.nav-links a[aria-current="page"] {
  color: var(--color-ink);
}
.nav-links a:hover::after,
.nav-links a[aria-current="page"]::after {
  transform: scaleX(1);
}

.nav-links a.nav-cta {
  border: 1.5px solid var(--color-accent);
  border-radius: var(--radius);
  padding: var(--space-2) var(--space-4);
  color: var(--color-accent);
  font-weight: 600;
  letter-spacing: 0.02em;
  transition: background-color 0.15s var(--ease), color 0.15s var(--ease);
}
.nav-links a.nav-cta::after {
  content: none;
}
.nav-links a.nav-cta:hover,
.nav-links a.nav-cta:focus-visible {
  background: var(--color-accent);
  color: var(--color-accent-ink);
}

.wordmark {
  transition: color 0.15s var(--ease);
}
.wordmark:hover {
  color: var(--color-accent);
}

.nav-toggle {
  display: none;
  flex-direction: column;
  justify-content: center;
  gap: 5px;
  width: 32px;
  height: 32px;
  background: none;
  border: none;
  cursor: pointer;
  padding: 0;
}
.nav-toggle span {
  display: block;
  height: 1.5px;
  background: var(--color-ink);
  width: 100%;
}

/* ---------------------------------------------------------
   Hero / about
--------------------------------------------------------- */
.hero {
  padding-block: var(--space-24) var(--space-16);
  max-width: var(--content-width);
}

.eyebrow {
  font-size: var(--step--1);
  color: var(--color-accent-2);
  text-transform: uppercase;
  letter-spacing: 0.08em;
  margin-bottom: var(--space-3);
}

.hero h1 {
  margin-bottom: var(--space-3);
}

.tagline {
  font-size: var(--step-1);
  color: var(--color-ink-muted);
  margin-bottom: var(--space-6);
}

.bio {
  max-width: 34rem;
  margin-bottom: var(--space-12);
}

.skills h2 {
  font-size: var(--step-0);
  font-family: var(--font-body);
  font-weight: 600;
  margin-bottom: var(--space-4);
}

.skills-list {
  display: flex;
  flex-direction: column;
  gap: var(--space-2);
}

.skills-row {
  display: grid;
  grid-template-columns: 9rem 1fr;
  gap: var(--space-4);
  padding-block: var(--space-2);
  border-top: 1px solid var(--color-border);
  font-size: var(--step--1);
}
.skills-row:last-child {
  border-bottom: 1px solid var(--color-border);
}

.skills-row dt {
  color: var(--color-ink-muted);
}

/* ---------------------------------------------------------
   Section heading (shared)
--------------------------------------------------------- */
.section-heading {
  display: flex;
  align-items: baseline;
  justify-content: space-between;
  gap: var(--space-4);
  margin-bottom: var(--space-8);
}

.view-all {
  display: inline-block;
  font-size: var(--step--1);
  color: var(--color-ink-muted);
  white-space: nowrap;
  transition: color 0.15s var(--ease), transform 0.15s var(--ease);
}
.view-all:hover {
  color: var(--color-accent);
  transform: translateX(3px);
}

/* ---------------------------------------------------------
   Project cards (shared: home teaser + full list)
--------------------------------------------------------- */
.featured-projects {
  padding-block: var(--space-20);
  border-top: 1px solid var(--color-border);
}

.project-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(260px, 1fr));
  gap: var(--space-8);
}

.project-card {
  border: 1px solid var(--color-border);
  border-radius: var(--radius);
  padding: var(--space-6);
  background: var(--color-bg);
  scroll-margin-top: var(--space-16);
  transition: background-color 0.2s var(--ease), border-color 0.2s var(--ease), transform 0.2s var(--ease);
}
.project-card:hover {
  background-color: var(--color-bg-raised);
  border-color: var(--color-accent);
  transform: translateY(-2px);
}
.project-card:target {
  background-color: var(--color-bg-raised);
  border-color: var(--color-accent);
}

.project-card-head {
  display: flex;
  align-items: baseline;
  justify-content: space-between;
  gap: var(--space-4);
  margin-bottom: var(--space-2);
}

.project-card-head h2,
.project-card-head h3 {
  display: inline-flex;
  align-items: baseline;
  gap: var(--space-2);
}
.project-card-head a {
  color: inherit;
}
.project-card-head a:hover {
  color: var(--color-accent);
}
.project-card-head h3::after {
  content: '→';
  color: var(--color-accent);
  opacity: 0;
  transform: translateX(-4px);
  transition: opacity 0.2s var(--ease), transform 0.2s var(--ease);
}
.project-card:hover .project-card-head h3::after {
  opacity: 1;
  transform: translateX(0);
}

.project-year {
  font-size: var(--step--1);
  color: var(--color-ink-muted);
}

.project-card > p:not(.project-tags) {
  color: var(--color-ink-muted);
  margin-bottom: var(--space-2);
}

.project-tags {
  font-size: var(--step--1);
  color: var(--color-accent-2);
}

/* ---------------------------------------------------------
   Full project list (projects.html)
--------------------------------------------------------- */
.page-intro {
  padding-block: var(--space-20) var(--space-12);
}

.page-intro h1 {
  margin-top: var(--space-3);
}

.project-list {
  padding-bottom: var(--space-24);
}

.project-card .project-tags {
  margin-bottom: var(--space-4);
}

.project-bullets {
  display: flex;
  flex-direction: column;
  gap: var(--space-2);
  margin-bottom: var(--space-4);
}
.project-bullets li {
  position: relative;
  padding-left: var(--space-4);
  color: var(--color-ink-muted);
  font-size: var(--step--1);
}
.project-bullets li::before {
  content: '—';
  position: absolute;
  left: 0;
  color: var(--color-border);
}

.project-link {
  display: inline-flex;
  align-items: baseline;
  gap: var(--space-1);
  font-size: var(--step--1);
  font-weight: 600;
  color: var(--color-accent);
}
.project-link span {
  display: inline-block;
  transition: transform 0.15s var(--ease);
}
.project-link:hover {
  text-decoration: underline;
  text-underline-offset: 3px;
}
.project-link:hover span {
  transform: translateX(3px);
}

/* ---------------------------------------------------------
   Contact
--------------------------------------------------------- */
.contact {
  padding-block: var(--space-20) var(--space-24);
  border-top: 1px solid var(--color-border);
}

.contact-list {
  display: flex;
  flex-wrap: wrap;
  gap: var(--space-6);
  margin-top: var(--space-4);
  font-size: var(--step-1);
  font-family: var(--font-display);
}

.contact-list a {
  transition: color 0.15s var(--ease);
}
.contact-list a:hover {
  color: var(--color-accent);
}

/* ---------------------------------------------------------
   Footer
--------------------------------------------------------- */
.site-footer {
  border-top: 1px solid var(--color-border);
  padding: var(--space-6);
  text-align: center;
  font-size: var(--step--1);
  color: var(--color-ink-muted);
}

/* ---------------------------------------------------------
   Responsive
--------------------------------------------------------- */
@media (max-width: 640px) {
  .nav-toggle {
    display: flex;
  }

  .nav-links {
    position: absolute;
    top: 100%;
    left: 0;
    right: 0;
    background: var(--color-bg);
    border-bottom: 1px solid var(--color-border);
    flex-direction: column;
    gap: 0;
    display: none;
  }
  .nav-links.is-open {
    display: flex;
  }
  .nav-links a {
    padding: var(--space-4) var(--space-6);
    border-top: 1px solid var(--color-border);
  }

  .nav-links a.nav-cta {
    border: none;
    border-top: 1px solid var(--color-border);
    border-radius: 0;
    text-align: center;
    min-height: 44px;
    display: flex;
    align-items: center;
    justify-content: center;
  }

  .site-nav {
    position: relative;
  }

  .hero {
    padding-block: var(--space-16) var(--space-12);
  }

  .skills-row {
    grid-template-columns: 1fr;
    gap: var(--space-1);
  }

  .project-card-head {
    flex-direction: column;
    gap: var(--space-1);
  }

  .project-grid {
    grid-template-columns: 1fr;
  }

  .contact-list {
    flex-direction: column;
    gap: var(--space-3);
  }
}