/* ==========================================================================
   Luca Muroni — Portfolio
   Minimal dark theme, no external dependencies
   ========================================================================== */

:root {
  --bg-primary: #0a0a0a;
  --bg-secondary: #111111;
  --bg-tertiary: #1a1a1a;
  --text-primary: #ededed;
  --text-secondary: #a1a1a1;
  --text-muted: #6b6b6b;
  --accent: #3b82f6;
  --accent-hover: #2563eb;
  --border: #262626;
  --header-bg: rgba(10, 10, 10, 0.9);
  --font-sans: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, Oxygen, Ubuntu, sans-serif;
  --font-mono: "SF Mono", Consolas, "Liberation Mono", Menlo, monospace;
  --space-xs: 0.25rem;
  --space-sm: 0.5rem;
  --space-md: 1rem;
  --space-lg: 1.5rem;
  --space-xl: 2rem;
  --space-2xl: 3rem;
  --max-width: 72rem;
  --header-height: 4rem;
  --scroll-offset: calc(var(--header-height) + var(--space-sm));
  --radius: 0.5rem;
  --transition: 150ms ease;
}

@media (prefers-color-scheme: light) {
  :root {
    --bg-primary: #fafafa;
    --bg-secondary: #ffffff;
    --bg-tertiary: #f0f0f0;
    --text-primary: #1a1a1a;
    --text-secondary: #4a4a4a;
    --text-muted: #6b6b6b;
    --border: #e5e5e5;
    --header-bg: rgba(250, 250, 250, 0.92);
  }
}

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

html {
  scroll-behavior: smooth;
  scroll-padding-top: var(--scroll-offset);
}

body {
  margin: 0;
  font-family: var(--font-sans);
  font-size: 1rem;
  line-height: 1.6;
  color: var(--text-primary);
  background-color: var(--bg-primary);
  -webkit-font-smoothing: antialiased;
}

/* Skip link */
.skip-link {
  position: absolute;
  top: -100%;
  left: var(--space-md);
  padding: var(--space-sm) var(--space-md);
  background: var(--accent);
  color: #fff;
  text-decoration: none;
  border-radius: var(--radius);
  z-index: 1000;
  transition: top var(--transition);
}

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

/* Header & Nav */
.site-header {
  position: sticky;
  top: 0;
  z-index: 100;
  background: var(--header-bg);
  backdrop-filter: blur(8px);
  border-bottom: 1px solid var(--border);
}

.nav {
  display: flex;
  align-items: center;
  justify-content: space-between;
  max-width: var(--max-width);
  margin: 0 auto;
  padding: 0 var(--space-lg);
  height: var(--header-height);
}

.nav-logo {
  font-weight: 600;
  font-size: 1.125rem;
  color: var(--text-primary);
  text-decoration: none;
  font-family: var(--font-mono);
}

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

.nav-links a {
  color: var(--text-secondary);
  text-decoration: none;
  font-size: 0.875rem;
  transition: color var(--transition);
}

.nav-links a:hover,
.nav-links a:focus-visible {
  color: var(--text-primary);
}

.nav-toggle {
  display: none;
  flex-direction: column;
  gap: 5px;
  background: none;
  border: none;
  cursor: pointer;
  padding: var(--space-sm);
}

.nav-toggle span {
  display: block;
  width: 22px;
  height: 2px;
  background: var(--text-primary);
  transition: transform var(--transition), opacity var(--transition);
}

/* Main layout */
main {
  max-width: var(--max-width);
  margin: 0 auto;
  padding: 0 var(--space-lg) var(--space-2xl);
}

/* Hero */
.hero {
  padding: var(--space-2xl) 0;
  min-height: calc(100vh - var(--header-height) - 4rem);
  display: flex;
  flex-direction: column;
  justify-content: center;
}

.hero-label {
  font-size: 0.875rem;
  color: var(--accent);
  font-family: var(--font-mono);
  margin: 0 0 var(--space-sm);
  text-transform: uppercase;
  letter-spacing: 0.05em;
}

.hero h1 {
  font-size: clamp(2.5rem, 6vw, 3.5rem);
  font-weight: 600;
  line-height: 1.1;
  margin: 0 0 var(--space-md);
  letter-spacing: -0.02em;
}

.hero-tagline {
  font-size: 1.125rem;
  color: var(--text-secondary);
  margin: 0 0 var(--space-lg);
  font-family: var(--font-mono);
}

.hero-desc {
  font-size: 1.125rem;
  color: var(--text-secondary);
  max-width: 36rem;
  margin: 0 0 var(--space-xl);
  line-height: 1.7;
}

.hero-actions {
  display: flex;
  flex-wrap: wrap;
  gap: var(--space-md);
}

/* Buttons */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  padding: 0.625rem 1.25rem;
  font-size: 0.875rem;
  font-weight: 500;
  text-decoration: none;
  border-radius: var(--radius);
  border: 1px solid transparent;
  cursor: pointer;
  transition: background var(--transition), border-color var(--transition), color var(--transition);
}

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

.btn-primary:hover,
.btn-primary:focus-visible {
  background: var(--accent-hover);
  border-color: var(--accent-hover);
}

.btn-secondary {
  background: transparent;
  color: var(--text-primary);
  border-color: var(--border);
}

.btn-secondary:hover,
.btn-secondary:focus-visible {
  border-color: var(--text-muted);
  background: var(--bg-secondary);
}

/* Sections */
.section {
  padding: var(--space-2xl) 0;
  border-top: 1px solid var(--border);
}

.section-title {
  font-size: 1.5rem;
  font-weight: 600;
  margin: 0 0 var(--space-xl);
  letter-spacing: -0.01em;
  scroll-margin-top: var(--scroll-offset);
}

.section-content p {
  color: var(--text-secondary);
  max-width: 42rem;
  margin: 0 0 var(--space-md);
}

.section-content p:last-child {
  margin-bottom: 0;
}

.about-layout {
  display: flex;
  align-items: flex-start;
  gap: var(--space-xl);
}

.about-photo {
  width: 10rem;
  height: 10rem;
  border-radius: 50%;
  object-fit: cover;
  object-position: top center;
  border: 2px solid var(--border);
  flex-shrink: 0;
}

/* Cards */
.card {
  background: var(--bg-secondary);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: var(--space-lg);
  transition: border-color var(--transition);
}

.card:hover {
  border-color: rgba(59, 130, 246, 0.4);
}

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

.card-title {
  font-size: 1rem;
  font-weight: 600;
  margin: 0;
}

.card-date {
  font-size: 0.8125rem;
  color: var(--text-muted);
  font-family: var(--font-mono);
}

.card-subtitle {
  font-size: 0.875rem;
  color: var(--text-secondary);
  margin: 0 0 var(--space-md);
}

.card-list {
  margin: 0;
  padding-left: 1.25rem;
  color: var(--text-secondary);
  font-size: 0.9375rem;
}

.card-list li {
  margin-bottom: var(--space-xs);
}

.card-list li:last-child {
  margin-bottom: 0;
}

.card p {
  color: var(--text-secondary);
  font-size: 0.9375rem;
  margin: var(--space-sm) 0 0;
  line-height: 1.6;
}

/* Timeline */
.timeline {
  display: flex;
  flex-direction: column;
  gap: var(--space-lg);
}

/* Skills */
.skills-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(16rem, 1fr));
  gap: var(--space-lg);
}

.skill-label {
  font-size: 0.75rem;
  font-weight: 500;
  color: var(--text-muted);
  text-transform: uppercase;
  letter-spacing: 0.05em;
  margin: 0 0 var(--space-sm);
}

.tags {
  display: flex;
  flex-wrap: wrap;
  gap: var(--space-sm);
}

.tag {
  display: inline-block;
  padding: 0.25rem 0.625rem;
  font-size: 0.8125rem;
  font-family: var(--font-mono);
  background: var(--bg-tertiary);
  color: var(--text-secondary);
  border-radius: 0.25rem;
  border: 1px solid var(--border);
}

/* Work grid */
.work-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(18rem, 1fr));
  gap: var(--space-lg);
}

.card-featured {
  grid-column: 1 / -1;
}

.tags-spaced {
  margin-top: var(--space-md);
}

.card-actions {
  display: flex;
  flex-wrap: wrap;
  gap: var(--space-md);
  margin: var(--space-md) 0 0;
}

/* Thesis reader */
.thesis-toolbar {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: var(--space-md);
  flex-wrap: wrap;
  padding: var(--space-md) var(--space-lg);
  background: var(--bg-secondary);
  border-bottom: 1px solid var(--border);
}

.thesis-toolbar a {
  color: var(--text-secondary);
  text-decoration: none;
  font-size: 0.875rem;
}

.thesis-toolbar a:hover,
.thesis-toolbar a:focus-visible {
  color: var(--accent);
}

.thesis-toolbar-title {
  display: flex;
  flex-direction: column;
  gap: 0.15rem;
  min-width: 0;
}

.thesis-toolbar-title strong {
  font-size: 0.9375rem;
  color: var(--text-primary);
}

.thesis-toolbar-title span {
  font-size: 0.8125rem;
  color: var(--text-muted);
}

.thesis-toolbar-actions {
  display: flex;
  flex-wrap: wrap;
  gap: var(--space-sm);
}

.thesis-reader {
  height: calc(100vh - 4.5rem);
  min-height: 24rem;
  padding: var(--space-md);
  background: var(--bg-primary);
}

.thesis-frame {
  width: 100%;
  height: 100%;
  border: 1px solid var(--border);
  border-radius: var(--radius);
  background: #fff;
}

.thesis-fallback {
  margin: var(--space-md) 0 0;
  text-align: center;
  font-size: 0.875rem;
  color: var(--text-muted);
}

.thesis-fallback a {
  color: var(--accent);
}

/* Legal / privacy */
.legal-back {
  margin-left: auto;
  color: var(--text-secondary);
  text-decoration: none;
  font-size: 0.875rem;
}

.legal-back:hover,
.legal-back:focus-visible {
  color: var(--accent);
}

.legal-page {
  max-width: 42rem;
  margin: 0 auto;
  padding: var(--space-2xl) var(--space-lg);
}

.legal-page h1 {
  margin: 0 0 var(--space-sm);
  font-size: 2rem;
  letter-spacing: -0.02em;
}

.legal-updated {
  margin: 0 0 var(--space-xl);
  font-size: 0.875rem;
  color: var(--text-muted);
}

.legal-page section {
  margin-bottom: var(--space-xl);
}

.legal-page h2 {
  margin: 0 0 var(--space-sm);
  font-size: 1.125rem;
}

.legal-page p {
  margin: 0 0 var(--space-md);
  color: var(--text-secondary);
  line-height: 1.7;
}

.legal-page p:last-child {
  margin-bottom: 0;
}

.legal-page a {
  color: var(--accent);
}

/* Contact */
.contact-block p {
  color: var(--text-secondary);
  margin: 0 0 var(--space-lg);
}

.contact-list {
  list-style: none;
  margin: 0 0 var(--space-xl);
  padding: 0;
}

.contact-list li {
  display: flex;
  flex-wrap: wrap;
  gap: var(--space-sm);
  padding: var(--space-sm) 0;
  border-bottom: 1px solid var(--border);
}

.contact-list li:last-child {
  border-bottom: none;
}

.contact-label {
  min-width: 5rem;
  font-size: 0.875rem;
  color: var(--text-muted);
  font-family: var(--font-mono);
}

.contact-list a {
  color: var(--accent);
  text-decoration: none;
}

.contact-list a:hover,
.contact-list a:focus-visible {
  text-decoration: underline;
  color: var(--accent-hover);
}

.text-muted {
  color: var(--text-muted);
}

.cv-links {
  display: flex;
  flex-wrap: wrap;
  gap: var(--space-md);
}

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

.site-footer p {
  margin: 0;
  font-size: 0.875rem;
  color: var(--text-muted);
}

.site-footer a {
  color: var(--text-secondary);
  text-decoration: none;
}

.site-footer a:hover,
.site-footer a:focus-visible {
  color: var(--accent);
}

/* Focus styles */
a:focus-visible,
button:focus-visible {
  outline: 2px solid var(--accent);
  outline-offset: 2px;
}

/* Responsive */
@media (max-width: 768px) {
  .nav-toggle {
    display: flex;
    min-width: 2.75rem;
    min-height: 2.75rem;
    align-items: center;
    justify-content: center;
    touch-action: manipulation;
    -webkit-tap-highlight-color: transparent;
  }

  .nav-links {
    position: absolute;
    top: var(--header-height);
    left: 0;
    right: 0;
    z-index: 1;
    flex-direction: column;
    background: var(--bg-primary);
    border-bottom: 1px solid var(--border);
    padding: var(--space-md) var(--space-lg);
    gap: var(--space-md);
    display: none;
  }

  .nav-links.open {
    display: flex;
  }

  .hero {
    min-height: auto;
    padding: var(--space-xl) 0;
  }

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

  .about-layout {
    flex-direction: column;
    align-items: center;
    text-align: center;
  }

  .about-photo {
    width: 8.5rem;
    height: 8.5rem;
  }

  .thesis-toolbar {
    flex-direction: column;
    align-items: stretch;
  }

  .thesis-toolbar-actions {
    justify-content: stretch;
  }

  .thesis-toolbar-actions .btn {
    flex: 1;
  }
}

@media (prefers-reduced-motion: reduce) {
  html {
    scroll-behavior: auto;
  }

  *,
  *::before,
  *::after {
    transition-duration: 0.01ms !important;
  }
}