/* =========================================
   ATANAS ORESHKOV PORTFOLIO - STYLE
   Material 3 Compatible
   ========================================= */

:root {
  /* Let the UA theme native controls (form fields, scrollbars) to match. */
  color-scheme: light dark;

  /* Colors mapped to M3 Tokens */
  --bg-color: var(--md-sys-color-surface);
  --bg-secondary: var(--md-sys-color-surface-container-low);
  --bg-accent: var(--md-sys-color-primary-container);

  --text-primary: var(--md-sys-color-on-surface);
  --text-secondary: var(--md-sys-color-on-surface-variant);
  /* Low-emphasis TEXT uses the on-surface-variant role. The `outline` role is
     reserved for non-text boundaries/dividers and is not contrast-guaranteed. */
  --text-tertiary: var(--md-sys-color-on-surface-variant);

  --accent-color: var(--md-sys-color-primary);
  --accent-dark: var(--md-ref-palette-primary30);
  --accent-light: var(--md-sys-color-primary-container);

  --border-color: var(--md-sys-color-outline-variant);

  /* Footer Colors */
  --footer-bg: var(--md-sys-color-surface-container-high);
  --footer-text: var(--md-sys-color-on-surface);
  --footer-link: var(--md-sys-color-primary);

  /* Typography */
  --font-main: 'Roboto Flex', 'Roboto', -apple-system, BlinkMacSystemFont, 'Segoe UI', sans-serif;
  --font-mono: 'SF Mono', Monaco, 'Cascadia Code', 'Roboto Mono', monospace;

  /* Spacing System */
  --space-xs: 0.25rem;
  --space-sm: 0.5rem;
  --space-md: 1rem;
  --space-lg: 2rem;
  --space-xl: 3rem;
  --space-2xl: 4rem;

  /* Max Content Width */
  --container-width: 960px;

  /* Transitions */
  --transition-fast: 150ms ease;
  --transition-base: 200ms ease;
  --transition-slow: 300ms ease;
}

/* =========================================
   RESET & BASE
   ========================================= */
*, *::before, *::after {
  box-sizing: border-box;
  margin: 0;
  padding: 0;
}

body {
  background-color: var(--bg-color);
  color: var(--text-primary);
  font-family: var(--font-main);
  line-height: 1.6;
  -webkit-font-smoothing: antialiased;
  /* Smooth the light/dark switch (disabled under prefers-reduced-motion below). */
  transition: background-color var(--transition-slow), color var(--transition-slow);
}

/* Keep native UA controls in sync with the manually-toggled theme. */
[data-theme="light"] { color-scheme: light; }
[data-theme="dark"]  { color-scheme: dark; }

/* =========================================
   ACCESSIBILITY
   ========================================= */

/* Visible keyboard focus indicator. Components reset their borders/outlines,
   so restore a clear focus ring for keyboard/switch users (WCAG 2.4.7/2.4.11). */
:where(a, button, .btn, .icon-btn, .theme-toggle, [tabindex]):focus-visible {
  outline: 3px solid var(--md-sys-color-primary);
  outline-offset: 2px;
  border-radius: var(--md-sys-shape-corner-small);
}

/* Respect users who request reduced motion (WCAG 2.3.3 + M3 motion guidance). */
@media (prefers-reduced-motion: reduce) {
  *, *::before, *::after {
    animation-duration: 0.01ms !important;
    animation-iteration-count: 1 !important;
    transition-duration: 0.01ms !important;
    scroll-behavior: auto !important;
  }
  .btn:hover,
  .tech-card:hover {
    transform: none;
  }
}

/* =========================================
   TYPOGRAPHY
   ========================================= */
h1, h2, h3, h4 {
  margin-bottom: var(--space-md);
  color: var(--text-primary);
  font-weight: 500;
}

h1 {
  font-size: var(--md-sys-typescale-display-large-size);
  line-height: var(--md-sys-typescale-display-large-line-height);
  letter-spacing: var(--md-sys-typescale-display-large-tracking);
  margin-bottom: var(--space-lg);
}
h2 {
  font-size: var(--md-sys-typescale-headline-large-size);
  line-height: var(--md-sys-typescale-headline-large-line-height);
  letter-spacing: var(--md-sys-typescale-headline-large-tracking);
  margin-bottom: var(--space-lg);
}
h3 {
  font-size: var(--md-sys-typescale-headline-small-size);
  line-height: var(--md-sys-typescale-headline-small-line-height);
}
h4 {
  font-size: var(--md-sys-typescale-title-medium-size);
  line-height: var(--md-sys-typescale-title-medium-line-height);
  letter-spacing: var(--md-sys-typescale-title-medium-tracking);
  margin-bottom: var(--space-md);
}

p {
  margin-bottom: var(--space-md);
  color: var(--text-secondary);
  line-height: var(--md-sys-typescale-body-large-line-height);
  letter-spacing: var(--md-sys-typescale-body-large-tracking);
}

ul, ol {
  margin-bottom: var(--space-md);
  margin-left: var(--space-lg);
  color: var(--text-secondary);
}

li {
  margin-bottom: var(--space-sm);
  line-height: var(--md-sys-typescale-body-large-line-height);
  letter-spacing: var(--md-sys-typescale-body-large-tracking);
}

a {
  color: var(--accent-color);
  text-decoration: none;
  transition: color var(--transition-base);
  font-weight: 500;
}

a:hover { color: var(--accent-dark); }

/* =========================================
   LAYOUT SYSTEM
   ========================================= */
.container {
  width: 90%;
  max-width: var(--container-width);
  margin: 0 auto;
}

.flex-group {
  display: flex;
  gap: var(--space-md);
  align-items: center;
  flex-wrap: wrap;
}

.section {
  padding: var(--space-2xl) 0;
}

.tech-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
  gap: var(--space-lg);
}

/* =========================================
   HEADER & NAVIGATION
   ========================================= */
.site-header {
  display: flex;
  justify-content: space-between;
  align-items: center;
  padding: var(--space-md) 0;
  border-bottom: 1px solid var(--border-color);
  position: sticky;
  top: 0;
  background-color: var(--bg-color);
  z-index: 100;
}

.logo {
  font-size: var(--md-sys-typescale-title-large-size);
  font-weight: 500;
}

.logo-link {
  color: var(--accent-color);
  text-decoration: none;
  display: flex;
  align-items: center;
  gap: var(--space-sm);
  transition: opacity var(--transition-base);
}

.logo-link:hover {
  opacity: 0.8;
  color: var(--accent-color);
}

.logo-icon {
  width: 24px;
  height: 24px;
  border-radius: var(--md-sys-shape-corner-small);
}

.theme-toggle {
  background: none;
  border: none;
  cursor: pointer;
  padding: 8px;
  display: flex;
  align-items: center;
  justify-content: center;
  color: var(--text-secondary);
  border-radius: var(--md-sys-shape-corner-full);
  transition: background-color var(--transition-base), color var(--transition-base);
}

.theme-toggle:hover {
  background-color: var(--bg-secondary);
  color: var(--accent-color);
}

.theme-toggle svg {
  width: 24px;
  height: 24px;
}

[data-theme="dark"] .sun-icon { display: block; }
[data-theme="dark"] .moon-icon { display: none; }
.sun-icon { display: none; }
.moon-icon { display: block; }

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

.nav-links a {
  color: var(--text-primary);
  font-size: var(--md-sys-typescale-label-large-size);
  letter-spacing: var(--md-sys-typescale-label-large-tracking);
}

/* =========================================
   HERO SECTION
   ========================================= */
.hero {
  padding-top: var(--space-2xl);
  padding-bottom: var(--space-2xl);
}

.hero-greeting {
  font-size: var(--md-sys-typescale-title-medium-size);
  color: var(--text-tertiary);
  margin-bottom: var(--space-sm);
}

.hero-name {
  font-size: var(--md-sys-typescale-display-large-size);
  line-height: var(--md-sys-typescale-display-large-line-height);
  letter-spacing: var(--md-sys-typescale-display-large-tracking);
  font-weight: var(--md-sys-typescale-display-large-weight);
  margin-bottom: var(--space-sm);
  color: var(--accent-color);
}

.hero-title {
  font-size: var(--md-sys-typescale-headline-medium-size);
  color: var(--text-secondary);
  font-weight: 400;
  margin-bottom: var(--space-lg);
}

.hero-description {
  font-size: var(--md-sys-typescale-body-large-size);
  max-width: 700px;
  margin-bottom: var(--space-xl);
}

/* =========================================
   BUTTONS (M3 Spec)
   ========================================= */
.btn {
  display: inline-block;
  padding: 0.75rem 1.5rem;
  font-size: var(--md-sys-typescale-label-large-size);
  font-weight: 500;
  letter-spacing: var(--md-sys-typescale-label-large-tracking);
  border-radius: var(--md-sys-shape-corner-full);
  transition: all var(--transition-base);
  cursor: pointer;
  border: none;
  text-align: center;
}

.btn:hover {
  transform: translateY(-1px);
  box-shadow: var(--md-sys-elevation-level1);
}

/* M3 state layers: the role's on-color mixed over the base at fixed opacities
   (hover 8%, pressed 10%) — theme-correct in both light and dark. */
.btn-primary { background-color: var(--md-sys-color-primary); color: var(--md-sys-color-on-primary); }
.btn-primary:hover { background-color: color-mix(in srgb, var(--md-sys-color-on-primary) 8%, var(--md-sys-color-primary)); }
.btn-primary:active { background-color: color-mix(in srgb, var(--md-sys-color-on-primary) 10%, var(--md-sys-color-primary)); }

.btn-secondary { background-color: var(--md-sys-color-secondary-container); color: var(--md-sys-color-on-secondary-container); }
.btn-secondary:hover { background-color: color-mix(in srgb, var(--md-sys-color-on-secondary-container) 8%, var(--md-sys-color-secondary-container)); }
.btn-secondary:active { background-color: color-mix(in srgb, var(--md-sys-color-on-secondary-container) 10%, var(--md-sys-color-secondary-container)); }

.btn-tertiary { background-color: transparent; color: var(--md-sys-color-primary); border: 1px solid var(--md-sys-color-outline); }
.btn-tertiary:hover { background-color: color-mix(in srgb, var(--md-sys-color-primary) 8%, transparent); }
.btn-tertiary:active { background-color: color-mix(in srgb, var(--md-sys-color-primary) 10%, transparent); }

/* =========================================
   TECHNOLOGY CARDS
   ========================================= */
.tech-card {
  background-color: var(--md-sys-color-surface-container-low);
  padding: var(--space-lg);
  border-radius: var(--md-sys-shape-corner-large);
  border: 1px solid var(--border-color);
  transition: all var(--transition-base);
  display: flex;
  flex-direction: column;
}

.tech-card:hover {
  transform: translateY(-4px);
  background-color: var(--md-sys-color-surface-container);
  box-shadow: var(--md-sys-elevation-level2);
}

.tech-card h3 { color: var(--accent-color); margin-bottom: var(--space-md); }

.tech-card--interest { background-color: var(--md-sys-color-primary-container); border-color: transparent; }
.tech-card--interest h3 { color: var(--md-sys-color-on-primary-container); }
.tech-card--interest p { color: var(--md-sys-color-on-primary-container); opacity: 0.9; }

/* =========================================
   PROJECT CARDS
   ========================================= */
.projects { background-color: var(--md-sys-color-surface-container-low); }

.project-card {
  background-color: var(--md-sys-color-surface);
  padding: var(--space-xl);
  border-radius: var(--md-sys-shape-corner-large);
  border: 1px solid var(--border-color);
  margin-bottom: var(--space-lg);
}

.project-header {
  margin-bottom: var(--space-lg);
  border-bottom: 1px solid var(--border-color);
  padding-bottom: var(--space-lg);
}

.project-meta { font-size: var(--md-sys-typescale-label-medium-size); letter-spacing: var(--md-sys-typescale-label-medium-tracking); color: var(--text-tertiary); font-weight: 500; }

.tech-badge {
  display: inline-block;
  background-color: var(--md-sys-color-secondary-container);
  color: var(--md-sys-color-on-secondary-container);
  padding: 0.25rem 0.75rem;
  border-radius: var(--md-sys-shape-corner-small);
  font-size: var(--md-sys-typescale-label-small-size);
  letter-spacing: var(--md-sys-typescale-label-small-tracking);
  font-weight: 500;
}

.project-highlights {
  background-color: var(--md-sys-color-surface-container-high);
  padding: var(--space-lg);
  border-radius: var(--md-sys-shape-corner-medium);
  margin-bottom: var(--space-lg);
}

.project-highlights h4 { color: var(--accent-color); }

/* =========================================
   FOOTER
   ========================================= */
footer {
  background-color: var(--footer-bg);
  color: var(--footer-text);
  padding: var(--space-2xl) 0;
  margin-top: var(--space-2xl);
  border-top: 1px solid var(--border-color);
}

footer .container { padding: 0 var(--space-md); text-align: left; }

/* Pre-footer CTA */
.pre-footer {
  text-align: center;
  padding-bottom: var(--space-2xl);
  border-bottom: 1px solid var(--border-color);
  margin-bottom: var(--space-2xl);
}

.pre-footer h2 { margin-bottom: var(--space-sm); }
.pre-footer p { margin-bottom: var(--space-lg); max-width: 600px; margin-inline: auto; }

/* Footer Grid */
.footer-grid {
  display: grid;
  grid-template-columns: 2fr 1fr 1fr 1fr;
  gap: var(--space-2xl);
  margin-bottom: var(--space-2xl);
}

.footer-col h3 {
  font-size: var(--md-sys-typescale-title-medium-size);
  margin-bottom: var(--space-lg);
  color: var(--text-primary);
}

.footer-bio {
  font-size: var(--md-sys-typescale-body-medium-size);
  margin-bottom: var(--space-lg);
  max-width: 320px;
}

.footer-links {
  list-style: none;
  margin: 0;
}

.footer-links li { margin-bottom: var(--space-md); }

.footer-links a {
  color: var(--text-secondary);
  font-size: var(--md-sys-typescale-body-medium-size);
  font-weight: 400;
  transition: color var(--transition-base);
}

.footer-links a:hover { color: var(--accent-color); }

/* Social Icons (M3 IconButton Style) */
.footer-social {
  display: flex;
  gap: var(--space-sm);
}

.icon-btn {
  display: inline-flex;
  width: 48px;
  height: 48px;
  border-radius: var(--md-sys-shape-corner-full);
  align-items: center;
  justify-content: center;
  transition: background-color var(--transition-base), color var(--transition-base);
  color: var(--text-secondary);
}

.icon-btn:hover {
  background-color: var(--md-sys-color-secondary-container);
  color: var(--md-sys-color-on-secondary-container);
}

.icon-btn svg { width: 24px; height: 24px; }

/* Footer Bottom */
.footer-bottom {
  display: flex;
  justify-content: space-between;
  align-items: center;
  padding-top: var(--space-lg);
  border-top: 1px solid var(--border-color);
  flex-wrap: wrap;
  gap: var(--space-md);
}

.footer-copyright {
  font-size: var(--md-sys-typescale-body-small-size);
  color: var(--text-tertiary);
}

.footer-badge {
  font-size: var(--md-sys-typescale-label-small-size);
  letter-spacing: var(--md-sys-typescale-label-small-tracking);
  color: var(--text-tertiary);
  padding: 4px 12px;
  border-radius: var(--md-sys-shape-corner-full);
  background-color: var(--md-sys-color-surface-container);
}

/* =========================================
   HELPERS (migrated from inline styles)
   ========================================= */
.header-actions {
  display: flex;
  align-items: center;
  gap: var(--space-lg);
}

.container--flush {
  width: 100%;
  padding: 0;
}

.section--center { text-align: center; }

.mt-2xl { margin-top: var(--space-2xl); }

.project-tech {
  display: flex;
  flex-wrap: wrap;
  gap: var(--space-xs);
  margin-bottom: var(--space-lg);
}

#plugin-card-container {
  display: flex;
  justify-content: center;
  margin: var(--space-md) 0;
  min-height: 320px; /* Prevent layout shift */
}

/* =========================================
   RESPONSIVE DESIGN
   ========================================= */
/* Medium window (tablet): collapse the 4-up footer to a 2-up grid before
   it drops to a single column on compact widths. */
@media (max-width: 900px) {
  .footer-grid {
    grid-template-columns: 1fr 1fr;
    gap: var(--space-xl);
  }
}

@media (max-width: 768px) {
  .hero-name { font-size: 2.5rem; }
  .btn { width: 100%; }

  .footer-grid {
    grid-template-columns: 1fr;
    gap: var(--space-xl);
    text-align: center;
  }

  .footer-bio { margin-inline: auto; }
  .footer-social { justify-content: center; }
  .footer-bottom { justify-content: center; text-align: center; }
}