/* Mobile-first · 320px → 4K · Apple / Vercel / Linear inspired */

:root {
  --bg: #ffffff;
  --bg-subtle: #fafafa;
  --text: #0a0a0a;
  --text-secondary: #525252;
  --text-muted: #737373;
  --border: #e5e5e5;
  --border-hover: #d4d4d4;
  --focus: #0a0a0a;
  --font: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "Helvetica Neue", Arial, sans-serif;
  --font-mono: ui-monospace, "SF Mono", "Cascadia Code", "Source Code Pro", Menlo, monospace;
  --space-xs: 0.25rem;
  --space-sm: 0.5rem;
  --space-md: 1rem;
  --space-lg: 1.5rem;
  --space-xl: 2.5rem;
  --space-2xl: 4rem;
  --space-3xl: 6rem;
  --content: min(100% - 2rem, 40rem);
  --page: min(100% - 2rem, 72rem);
  --radius: 6px;
  --transition: 150ms ease;
}

@media (min-width: 640px) {
  :root {
    --content: min(100% - 3rem, 42rem);
    --page: min(100% - 3rem, 72rem);
  }
}

@media (min-width: 1536px) {
  :root {
    --space-2xl: 5rem;
    --space-3xl: 8rem;
  }
}

*, *::before, *::after {
  box-sizing: border-box;
}

html {
  scroll-behavior: smooth;
  -webkit-text-size-adjust: 100%;
}

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

body {
  margin: 0;
  font-family: var(--font);
  font-size: 0.9375rem;
  line-height: 1.65;
  color: var(--text);
  background: var(--bg);
  -webkit-font-smoothing: antialiased;
}

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

a {
  color: inherit;
  text-decoration-thickness: 1px;
  text-underline-offset: 3px;
}

a:hover { color: var(--text-secondary); }

:focus { outline: none; }
:focus-visible {
  outline: 2px solid var(--focus);
  outline-offset: 2px;
}

.skip-link {
  position: absolute;
  top: -100%;
  left: var(--space-md);
  z-index: 100;
  padding: var(--space-sm) var(--space-md);
  background: var(--text);
  color: var(--bg);
  font-size: 0.875rem;
  text-decoration: none;
  border-radius: var(--radius);
}

.skip-link:focus { top: var(--space-md); }

.container {
  width: var(--page);
  margin-inline: auto;
}

.container--narrow {
  width: var(--content);
  margin-inline: auto;
}

/* Header */
.site-header {
  position: sticky;
  top: 0;
  z-index: 50;
  background: rgba(255, 255, 255, 0.85);
  backdrop-filter: blur(8px);
  -webkit-backdrop-filter: blur(8px);
  border-bottom: 1px solid var(--border);
}

.site-header__inner {
  display: flex;
  align-items: center;
  justify-content: space-between;
  height: 3rem;
  gap: var(--space-md);
}

.site-logo {
  font-size: 0.875rem;
  font-weight: 500;
  letter-spacing: -0.01em;
  text-decoration: none;
  color: var(--text);
}

.site-nav {
  display: none;
  gap: var(--space-lg);
  list-style: none;
  margin: 0;
  padding: 0;
}

.site-nav a {
  font-size: 0.8125rem;
  color: var(--text-muted);
  text-decoration: none;
  transition: color var(--transition);
}

.site-nav a:hover,
.site-nav a[aria-current="true"] {
  color: var(--text);
}

.menu-toggle {
  display: flex;
  align-items: center;
  justify-content: center;
  width: 2.25rem;
  height: 2.25rem;
  padding: 0;
  border: none;
  background: transparent;
  color: var(--text);
  cursor: pointer;
  border-radius: var(--radius);
}

.menu-toggle:hover { background: var(--bg-subtle); }

@media (min-width: 768px) {
  .site-nav { display: flex; }
  .menu-toggle { display: none; }
}

.mobile-nav {
  display: none;
  border-top: 1px solid var(--border);
  padding: var(--space-md) 0;
}

.mobile-nav.is-open { display: block; }

.mobile-nav ul {
  list-style: none;
  margin: 0;
  padding: 0;
  display: flex;
  flex-direction: column;
  gap: var(--space-sm);
}

.mobile-nav a {
  display: block;
  padding: var(--space-sm) 0;
  font-size: 0.875rem;
  color: var(--text-secondary);
  text-decoration: none;
}

/* Sections */
.section {
  padding-block: var(--space-2xl);
}

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

.section__label {
  font-size: 0.75rem;
  font-weight: 500;
  letter-spacing: 0.04em;
  text-transform: uppercase;
  color: var(--text-muted);
  margin: 0 0 var(--space-lg);
}

.section__title {
  font-size: 1rem;
  font-weight: 500;
  letter-spacing: -0.02em;
  margin: 0 0 var(--space-md);
  color: var(--text);
}

.section__title--spaced {
  margin-top: var(--space-xl);
}

/* Hero */
.hero {
  padding-block: var(--space-2xl) var(--space-xl);
}

@media (min-width: 768px) {
  .hero { padding-block: var(--space-3xl) var(--space-2xl); }
}

.hero__layout {
  display: flex;
  align-items: flex-start;
  gap: var(--space-md);
}

@media (min-width: 640px) {
  .hero__layout { gap: var(--space-lg); }
}

.hero__photo {
  width: 3rem;
  height: 3rem;
  border-radius: 50%;
  object-fit: cover;
  flex-shrink: 0;
  border: 1px solid var(--border);
  background: var(--bg-subtle);
}

@media (min-width: 640px) {
  .hero__photo {
    width: 4rem;
    height: 4rem;
  }
}

@media (min-width: 1024px) {
  .hero__photo {
    width: 5rem;
    height: 5rem;
  }
}

.hero__content {
  flex: 1;
  min-width: 0;
}

.hero__name {
  font-size: clamp(1.375rem, 4vw, 1.75rem);
  font-weight: 600;
  letter-spacing: -0.03em;
  line-height: 1.2;
  margin: 0 0 var(--space-md);
}

.hero__headline {
  font-size: clamp(0.9375rem, 2.5vw, 1.0625rem);
  color: var(--text-secondary);
  max-width: 36em;
  margin: 0 0 var(--space-md);
}

.hero__about {
  font-size: 0.875rem;
  color: var(--text-muted);
  max-width: 40em;
  line-height: 1.6;
  margin: 0 0 var(--space-lg);
}

.hero__meta {
  font-size: 0.8125rem;
  color: var(--text-muted);
  margin: 0 0 var(--space-lg);
}

.hero__links {
  display: flex;
  flex-wrap: wrap;
  gap: var(--space-md) var(--space-lg);
  list-style: none;
  margin: 0;
  padding: 0;
}

.hero__links a {
  font-size: 0.875rem;
  color: var(--text);
  text-decoration: underline;
  text-decoration-color: var(--border);
}

.hero__links a:hover {
  text-decoration-color: var(--text);
}

/* Lists & cards */
.list {
  list-style: none;
  margin: 0;
  padding: 0;
  display: flex;
  flex-direction: column;
  gap: var(--space-lg);
}

.list-item {
  padding-bottom: var(--space-lg);
  border-bottom: 1px solid var(--border);
}

.list-item:last-child {
  padding-bottom: 0;
  border-bottom: none;
}

.list-item__header {
  display: flex;
  flex-wrap: wrap;
  align-items: baseline;
  justify-content: space-between;
  gap: var(--space-sm) var(--space-md);
  margin-bottom: var(--space-xs);
}

.list-item__title {
  font-size: 0.9375rem;
  font-weight: 500;
  letter-spacing: -0.01em;
  margin: 0;
}

.list-item__period {
  font-size: 0.8125rem;
  color: var(--text-muted);
  font-variant-numeric: tabular-nums;
  white-space: nowrap;
}

.list-item__subtitle {
  font-size: 0.8125rem;
  color: var(--text-muted);
  margin: 0 0 var(--space-sm);
}

.list-item__desc {
  font-size: 0.875rem;
  color: var(--text-secondary);
  margin: 0 0 var(--space-sm);
}

.list-item__bullets {
  margin: 0;
  padding-left: 1.125rem;
  font-size: 0.8125rem;
  color: var(--text-secondary);
}

.list-item__bullets li + li { margin-top: var(--space-xs); }

/* Tags */
.tags {
  display: flex;
  flex-wrap: wrap;
  gap: var(--space-sm);
  list-style: none;
  margin: var(--space-sm) 0 0;
  padding: 0;
}

.tag {
  font-size: 0.75rem;
  font-family: var(--font-mono);
  color: var(--text-muted);
  padding: 0.125rem 0.5rem;
  border: 1px solid var(--border);
  border-radius: var(--radius);
}

/* GitHub */
.github-grid {
  display: grid;
  gap: var(--space-xl);
}

@media (min-width: 768px) {
  .github-grid {
    grid-template-columns: 1fr 1fr;
    gap: var(--space-2xl);
  }
}

.repo-card__link {
  text-decoration: none;
  display: block;
}

.repo-card__link:hover .repo-card__name {
  text-decoration: underline;
}

.repo-card__name {
  font-size: 0.9375rem;
  font-weight: 500;
  margin: 0 0 var(--space-xs);
}

.repo-card__desc {
  font-size: 0.8125rem;
  color: var(--text-secondary);
  margin: 0 0 var(--space-sm);
  line-height: 1.5;
}

.repo-card__meta {
  font-size: 0.75rem;
  color: var(--text-muted);
  font-variant-numeric: tabular-nums;
}

.activity-item {
  display: flex;
  gap: var(--space-md);
  font-size: 0.8125rem;
  color: var(--text-secondary);
  padding-block: var(--space-sm);
  border-bottom: 1px solid var(--border);
}

.activity-item:last-child { border-bottom: none; }

.activity-item__time {
  flex-shrink: 0;
  width: 4.5rem;
  color: var(--text-muted);
  font-variant-numeric: tabular-nums;
  font-size: 0.75rem;
}

.activity-item a {
  color: var(--text);
  text-decoration: none;
}

.activity-item a:hover { text-decoration: underline; }

.lang-bar {
  display: flex;
  height: 4px;
  border-radius: 2px;
  overflow: hidden;
  background: var(--border);
  margin: var(--space-md) 0 var(--space-sm);
}

.lang-bar__segment { height: 100%; }

.lang-legend {
  display: flex;
  flex-wrap: wrap;
  gap: var(--space-sm) var(--space-md);
  list-style: none;
  margin: 0;
  padding: 0;
}

.lang-legend li {
  font-size: 0.75rem;
  color: var(--text-muted);
  font-family: var(--font-mono);
}

.lang-legend__dot {
  display: inline-block;
  width: 6px;
  height: 6px;
  border-radius: 50%;
  margin-right: 0.375rem;
  vertical-align: middle;
}

/* Skills */
.skills {
  display: flex;
  flex-wrap: wrap;
  gap: var(--space-sm);
  list-style: none;
  margin: 0;
  padding: 0;
}

.skills li {
  font-size: 0.8125rem;
  color: var(--text-secondary);
}

.skills li:not(:last-child)::after {
  content: "·";
  margin-left: var(--space-sm);
  color: var(--border-hover);
}

/* Footer */
.site-footer {
  padding-block: var(--space-xl);
  border-top: 1px solid var(--border);
}

.site-footer p {
  margin: 0;
  font-size: 0.8125rem;
  color: var(--text-muted);
}

/* States */
.loading {
  font-size: 0.8125rem;
  color: var(--text-muted);
}

.error {
  font-size: 0.8125rem;
  color: var(--text-muted);
}

.fade-in {
  animation: fadeIn 400ms ease forwards;
  opacity: 0;
}

@keyframes fadeIn {
  to { opacity: 1; }
}

@media (prefers-reduced-motion: reduce) {
  .fade-in { opacity: 1; animation: none; }
}

/* External link indicator */
a[data-external]::after {
  content: " ↗";
  font-size: 0.75em;
  opacity: 0.5;
}