/* ==========================================================================
   James Burney - Personal Website
   Main Stylesheet
   ========================================================================== */

/* ==========================================================================
   CSS Custom Properties (Design Tokens)
   ========================================================================== */

:root {
  /* Typography */
  --font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, Helvetica, Arial, sans-serif;
  --font-size-xs: 0.75rem;
  --font-size-sm: 0.875rem;
  --font-size-base: 1rem;
  --font-size-lg: 1.125rem;
  --font-size-xl: 1.25rem;
  --font-size-2xl: 1.5rem;
  --font-size-3xl: 2rem;
  --font-size-4xl: 2.5rem;
  --font-size-5xl: 3rem;

  /* Spacing */
  --spacing-xs: 0.25rem;
  --spacing-sm: 0.5rem;
  --spacing-md: 1rem;
  --spacing-lg: 1.5rem;
  --spacing-xl: 2rem;
  --spacing-2xl: 3rem;
  --spacing-3xl: 4rem;
  --spacing-4xl: 6rem;

  /* Layout */
  --max-width: 1200px;
  --content-width: 800px;
  --nav-height: 64px;

  /* Border Radius */
  --radius-sm: 4px;
  --radius-md: 8px;
  --radius-lg: 12px;
  --radius-xl: 16px;
  --radius-full: 9999px;

  /* Shadows */
  --shadow-sm: 0 1px 2px rgba(0, 0, 0, 0.1);
  --shadow-md: 0 4px 6px rgba(0, 0, 0, 0.1);
  --shadow-lg: 0 10px 15px rgba(0, 0, 0, 0.1);
  --shadow-xl: 0 20px 25px rgba(0, 0, 0, 0.15);

  /* Transitions */
  --transition-fast: 150ms ease;
  --transition-base: 250ms ease;
  --transition-slow: 350ms ease;

  /* Z-index layers */
  --z-dropdown: 100;
  --z-sticky: 200;
  --z-overlay: 300;
  --z-modal: 400;
  --z-tooltip: 500;
}

/* ==========================================================================
   Base Reset & Defaults
   ========================================================================== */

*,
*::before,
*::after {
  box-sizing: border-box;
  margin: 0;
  padding: 0;
}

html {
  font-size: 16px;
  scroll-behavior: smooth;
  -webkit-text-size-adjust: 100%;
}

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

  *,
  *::before,
  *::after {
    animation-duration: 0.01ms !important;
    animation-iteration-count: 1 !important;
    transition-duration: 0.01ms !important;
  }
}

body {
  font-family: var(--font-family);
  font-size: var(--font-size-base);
  line-height: 1.6;
  color: var(--text-primary);
  background-color: var(--bg-primary);
  min-height: 100vh;
  transition: background-color var(--transition-base), color var(--transition-base);
}

/* ==========================================================================
   Typography
   ========================================================================== */

h1, h2, h3, h4, h5, h6 {
  font-weight: 600;
  line-height: 1.3;
  color: var(--text-primary);
  margin-bottom: var(--spacing-md);
}

h1 {
  font-size: var(--font-size-4xl);
  letter-spacing: -0.02em;
}

h2 {
  font-size: var(--font-size-3xl);
  letter-spacing: -0.01em;
}

h3 {
  font-size: var(--font-size-2xl);
}

h4 {
  font-size: var(--font-size-xl);
}

h5 {
  font-size: var(--font-size-lg);
}

h6 {
  font-size: var(--font-size-base);
}

p {
  margin-bottom: var(--spacing-md);
  color: var(--text-secondary);
}

a {
  color: var(--accent-blue);
  text-decoration: none;
  transition: color var(--transition-fast);
}

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

strong {
  font-weight: 600;
  color: var(--text-primary);
}

em {
  font-style: italic;
}

small {
  font-size: var(--font-size-sm);
}

/* ==========================================================================
   Layout Components
   ========================================================================== */

.container {
  width: 100%;
  max-width: var(--max-width);
  margin: 0 auto;
  padding: 0 var(--spacing-lg);
}

.content-container {
  max-width: var(--content-width);
  margin: 0 auto;
}

.section {
  padding: var(--spacing-4xl) 0;
}

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

/* ==========================================================================
   Header & Navigation
   ========================================================================== */

.header {
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  z-index: var(--z-sticky);
  background-color: var(--bg-primary);
  border-bottom: 1px solid var(--border-color);
  transition: background-color var(--transition-base), border-color var(--transition-base);
}

main {
  padding-top: var(--nav-height);
}

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

.header__logo {
  display: flex;
  align-items: center;
  gap: 10px;
  color: var(--text-primary);
  text-decoration: none;
  transition: opacity var(--transition-fast);
}

.header__logo:hover {
  opacity: 0.8;
  color: var(--accent-green);
}

.header__nav {
  display: flex;
  align-items: center;
  gap: var(--spacing-xl);
  height: 100%;
}

.nav__list {
  display: flex;
  list-style: none;
  gap: var(--spacing-lg);
  align-items: center;
  height: 100%;
  margin: 0;
  padding: 0;
}

.nav__list > li {
  display: flex;
  align-items: center;
  height: 100%;
}

.nav__link {
  font-size: var(--font-size-sm);
  font-weight: 500;
  color: var(--text-secondary);
  text-decoration: none;
  padding: var(--spacing-xs) var(--spacing-sm);
  position: relative;
  transition: color var(--transition-fast);
}

.nav__link::after {
  content: '';
  position: absolute;
  bottom: 0;
  left: 0;
  width: 0;
  height: 2px;
  background-color: var(--accent-green);
  transition: width var(--transition-base);
}

.nav__link:hover,
.nav__link--active {
  color: var(--text-primary);
}

.nav__link:hover::after,
.nav__link--active::after {
  width: 100%;
}

/* Dropdown Menu */
.nav__dropdown {
  position: relative;
}

.nav__dropdown-trigger {
  display: flex;
  align-items: center;
  gap: var(--spacing-xs);
  cursor: pointer;
}

.nav__dropdown-trigger::after {
  content: '';
  border: solid var(--text-secondary);
  border-width: 0 2px 2px 0;
  padding: 3px;
  transform: rotate(45deg);
  transition: transform var(--transition-fast);
}

.nav__dropdown:hover .nav__dropdown-trigger::after {
  transform: rotate(-135deg);
}

.nav__dropdown-menu {
  position: absolute;
  top: 100%;
  right: 0;
  min-width: 160px;
  background-color: var(--bg-secondary);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-md);
  padding: var(--spacing-sm) 0;
  opacity: 0;
  visibility: hidden;
  transform: translateY(-10px);
  transition: all var(--transition-fast);
  box-shadow: var(--shadow-lg);
}

.nav__dropdown:hover .nav__dropdown-menu {
  opacity: 1;
  visibility: visible;
  transform: translateY(0);
}

.nav__dropdown-item {
  display: block;
  padding: var(--spacing-sm) var(--spacing-lg);
  color: var(--text-secondary);
  transition: all var(--transition-fast);
}

.nav__dropdown-item:hover {
  background-color: var(--bg-primary);
  color: var(--text-primary);
}

/* Mobile Navigation */
.nav__toggle {
  display: none;
  flex-direction: column;
  justify-content: center;
  gap: 5px;
  width: 32px;
  height: 32px;
  background: none;
  border: none;
  cursor: pointer;
  padding: 4px;
}

.nav__toggle span {
  display: block;
  width: 100%;
  height: 2px;
  background-color: var(--text-primary);
  transition: all var(--transition-fast);
  border-radius: 1px;
}

.nav__toggle[aria-expanded="true"] span:nth-child(1) {
  transform: rotate(45deg) translate(5px, 5px);
}

.nav__toggle[aria-expanded="true"] span:nth-child(2) {
  opacity: 0;
}

.nav__toggle[aria-expanded="true"] span:nth-child(3) {
  transform: rotate(-45deg) translate(5px, -5px);
}

/* Theme Toggle */
.theme-toggle {
  display: flex;
  align-items: center;
  justify-content: center;
  width: 40px;
  height: 40px;
  background: none;
  border: 1px solid var(--border-color);
  border-radius: var(--radius-full);
  cursor: pointer;
  transition: all var(--transition-fast);
}

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

.theme-toggle__icon {
  width: 20px;
  height: 20px;
  color: var(--text-secondary);
  transition: color var(--transition-fast);
}

.theme-toggle:hover .theme-toggle__icon {
  color: var(--accent-green);
}

/* nav__theme-toggle — wraps the button in the nav list */
.nav__theme-toggle {
  display: flex;
  align-items: center;
  list-style: none;
}

/* ==========================================================================
   Hero Section
   ========================================================================== */

.hero {
  padding: var(--spacing-3xl) 0 var(--spacing-4xl);
}

.hero__tagline {
  font-size: var(--font-size-lg);
  color: var(--accent-green);
  font-weight: 500;
  margin-bottom: var(--spacing-sm);
}

.hero__title {
  font-size: var(--font-size-5xl);
  margin-bottom: var(--spacing-lg);
  background: linear-gradient(135deg, var(--text-primary) 0%, var(--accent-blue) 100%);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
}

.hero__description {
  font-size: var(--font-size-lg);
  color: var(--text-secondary);
  max-width: 600px;
  margin-bottom: var(--spacing-xl);
}

/* Interior page hero — tighter padding than the homepage hero */
.hero--page {
  padding: var(--spacing-xl) 0 var(--spacing-md);
}

.hero--page .hero__title {
  font-size: var(--font-size-3xl);
  margin-bottom: var(--spacing-sm);
}

.hero--page .hero__tagline {
  font-size: var(--font-size-sm);
  margin-bottom: var(--spacing-xs);
}

.hero--page .hero__description {
  margin-bottom: 0;
}

/* Remove top padding from first content section after an interior hero */
.hero--page + .section,
.hero--page + .section--tight {
  padding-top: var(--spacing-lg);
}

@media (max-width: 768px) {
  .hero--page {
    padding: var(--spacing-lg) 0 var(--spacing-sm);
  }
}

/* ==========================================================================
   Buttons
   ========================================================================== */

.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: var(--spacing-sm);
  padding: var(--spacing-md) var(--spacing-xl);
  font-family: var(--font-family);
  font-size: var(--font-size-sm);
  font-weight: 600;
  text-decoration: none;
  border-radius: var(--radius-md);
  border: none;
  cursor: pointer;
  transition: all var(--transition-fast);
}

.btn--primary {
  background-color: var(--accent-green);
  color: var(--bg-primary);
}

.btn--primary:hover {
  background-color: var(--accent-green-hover);
  transform: translateY(-2px);
  box-shadow: var(--shadow-md);
}

.btn--secondary {
  background-color: transparent;
  color: var(--text-primary);
  border: 1px solid var(--border-color);
}

.btn--secondary:hover {
  border-color: var(--accent-green);
  color: var(--accent-green);
}

.btn--ghost {
  background-color: transparent;
  color: var(--accent-blue);
  padding: var(--spacing-sm) var(--spacing-md);
}

.btn--ghost:hover {
  background-color: var(--bg-secondary);
}

/* ==========================================================================
   Cards
   ========================================================================== */

.card {
  background-color: var(--bg-secondary);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-lg);
  padding: var(--spacing-xl);
  transition: all var(--transition-base);
}

.card:hover {
  border-color: var(--accent-green);
  transform: translateY(-4px);
  box-shadow: var(--shadow-lg);
}

.card__image {
  width: 100%;
  height: 200px;
  object-fit: cover;
  border-radius: var(--radius-md);
  margin-bottom: var(--spacing-lg);
}

.card__title {
  font-size: var(--font-size-xl);
  margin-bottom: var(--spacing-sm);
}

.card__description {
  color: var(--text-secondary);
  margin-bottom: var(--spacing-lg);
}

.card__tags {
  display: flex;
  flex-wrap: wrap;
  gap: var(--spacing-sm);
}

.tag {
  display: inline-block;
  padding: var(--spacing-xs) var(--spacing-sm);
  font-size: var(--font-size-xs);
  font-weight: 500;
  background-color: var(--bg-primary);
  color: var(--text-secondary);
  border-radius: var(--radius-sm);
  border: 1px solid var(--border-color);
}

/* ==========================================================================
   Grid Layouts
   ========================================================================== */

.grid {
  display: grid;
  gap: var(--spacing-xl);
}

.grid--2 {
  grid-template-columns: repeat(2, 1fr);
}

.grid--3 {
  grid-template-columns: repeat(3, 1fr);
}

.grid--auto {
  grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
}

/* ==========================================================================
   Timeline (Experience Page)
   ========================================================================== */

.timeline {
  position: relative;
  padding-left: var(--spacing-xl);
}

.timeline::before {
  content: '';
  position: absolute;
  left: 0;
  top: 0;
  bottom: 0;
  width: 2px;
  background: linear-gradient(to bottom, var(--accent-green), var(--accent-blue));
}

.timeline__item {
  position: relative;
  padding-bottom: var(--spacing-2xl);
}

.timeline__item:last-child {
  padding-bottom: 0;
}

.timeline__item::before {
  content: '';
  position: absolute;
  left: calc(-1 * var(--spacing-xl) - 5px);
  top: 6px;
  width: 12px;
  height: 12px;
  background-color: var(--accent-green);
  border-radius: var(--radius-full);
  border: 2px solid var(--bg-primary);
}

.timeline__date {
  font-size: var(--font-size-sm);
  font-weight: 600;
  color: var(--accent-green);
  margin-bottom: var(--spacing-xs);
}

.timeline__title {
  font-size: var(--font-size-xl);
  margin-bottom: var(--spacing-xs);
}

.timeline__company {
  font-size: var(--font-size-base);
  color: var(--accent-blue);
  margin-bottom: var(--spacing-sm);
}

.timeline__description {
  color: var(--text-secondary);
}

/* ==========================================================================
   Footer
   ========================================================================== */

.footer {
  padding: var(--spacing-2xl) 0;
  border-top: 1px solid var(--border-color);
  background-color: var(--bg-secondary);
}

.footer__inner {
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: var(--spacing-lg);
  text-align: center;
}

.footer__badges {
  display: flex;
  flex-wrap: wrap;
  justify-content: center;
  gap: var(--spacing-lg);
}

.footer__badge {
  display: inline-flex;
  align-items: center;
  gap: var(--spacing-sm);
  padding: var(--spacing-sm) var(--spacing-md);
  font-size: var(--font-size-sm);
  color: var(--text-secondary);
  background-color: var(--bg-primary);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-md);
  transition: all var(--transition-fast);
}

.footer__badge:hover {
  border-color: var(--accent-green);
  color: var(--accent-green);
}

.footer__links {
  display: flex;
  gap: var(--spacing-lg);
}

.footer__link {
  color: var(--text-secondary);
  transition: color var(--transition-fast);
}

.footer__link:hover {
  color: var(--accent-green);
}

.footer__copyright {
  font-size: var(--font-size-sm);
  color: var(--text-secondary);
}

.footer__page-weight {
  font-size: var(--font-size-xs);
  color: var(--text-secondary);
  padding: var(--spacing-xs) var(--spacing-sm);
  background-color: var(--bg-primary);
  border-radius: var(--radius-sm);
}

/* ==========================================================================
   Low Power Mode
   ========================================================================== */

.low-power-indicator {
  position: fixed;
  bottom: var(--spacing-lg);
  left: var(--spacing-lg);
  display: none;
  align-items: center;
  gap: var(--spacing-sm);
  padding: var(--spacing-sm) var(--spacing-md);
  font-size: var(--font-size-sm);
  color: var(--text-secondary);
  background-color: var(--bg-secondary);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-md);
  z-index: var(--z-tooltip);
}

.low-power-indicator--active {
  display: flex;
}

body.low-power-mode .card:hover {
  transform: none;
}

body.low-power-mode * {
  animation: none !important;
  transition: none !important;
}

/* ==========================================================================
   Animations
   ========================================================================== */

@keyframes fadeInUp {
  from {
    opacity: 0;
    transform: translateY(20px);
  }
  to {
    opacity: 1;
    transform: translateY(0);
  }
}

@keyframes fadeIn {
  from {
    opacity: 0;
  }
  to {
    opacity: 1;
  }
}

.animate-on-scroll {
  opacity: 0;
  transform: translateY(20px);
  transition: opacity var(--transition-slow), transform var(--transition-slow);
}

.animate-on-scroll.is-visible {
  opacity: 1;
  transform: translateY(0);
}

/* ==========================================================================
   Responsive Design
   ========================================================================== */

@media (max-width: 1024px) {
  .grid--3 {
    grid-template-columns: repeat(2, 1fr);
  }
}

@media (max-width: 768px) {
  :root {
    --nav-height: 56px;
  }

  h1 {
    font-size: var(--font-size-3xl);
  }

  h2 {
    font-size: var(--font-size-2xl);
  }

  .hero__title {
    font-size: var(--font-size-3xl);
  }

  .nav__toggle {
    display: flex;
  }

  /* Reset desktop height stretching for mobile overlay */
  .nav__list,
  .nav__list > li {
    height: auto;
  }

  /* Mobile nav overlay — hidden by default */
  .nav__list {
    display: none;
  }

  /* Mobile nav overlay — open state */
  .nav__list.is-open {
    display: flex;
    flex-direction: column;
    align-items: center;
    justify-content: flex-start;
    gap: var(--spacing-xl);

    position: fixed;
    top: var(--nav-height);
    left: 0;
    width: 100vw;
    height: calc(100vh - var(--nav-height));

    /* Solid background — hardcoded to avoid variable cascade issues */
    background-color: #0d1117;

    padding: var(--spacing-3xl) var(--spacing-md) var(--spacing-2xl);
    z-index: var(--z-overlay);
    overflow-y: auto;
  }

  [data-theme="light"] .nav__list.is-open {
    background-color: #f6f8fa;
  }

  .nav__list.is-open li {
    list-style: none;
  }

  .nav__link {
    font-size: var(--font-size-xl);
    color: var(--text-primary);
    padding: var(--spacing-sm) var(--spacing-md);
  }

  .nav__theme-toggle {
    margin-top: auto;
  }

  .nav__theme-toggle .theme-toggle {
    display: flex;
  }

  .nav__dropdown-menu {
    position: static;
    opacity: 1;
    visibility: visible;
    transform: none;
    background: transparent;
    border: none;
    box-shadow: none;
    text-align: center;
  }

  .grid--2,
  .grid--3 {
    grid-template-columns: 1fr;
  }

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

  .container {
    padding: 0 var(--spacing-md);
  }
}

@media (max-width: 480px) {
  .hero__title {
    font-size: var(--font-size-2xl);
  }

  .btn {
    width: 100%;
    justify-content: center;
  }
}

/* ==========================================================================
   Utility Classes
   ========================================================================== */

.sr-only {
  position: absolute;
  width: 1px;
  height: 1px;
  padding: 0;
  margin: -1px;
  overflow: hidden;
  clip: rect(0, 0, 0, 0);
  white-space: nowrap;
  border: 0;
}

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

.text-left {
  text-align: left;
}

.text-right {
  text-align: right;
}

.mt-0 { margin-top: 0; }
.mt-1 { margin-top: var(--spacing-sm); }
.mt-2 { margin-top: var(--spacing-md); }
.mt-3 { margin-top: var(--spacing-lg); }
.mt-4 { margin-top: var(--spacing-xl); }

.mb-0 { margin-bottom: 0; }
.mb-1 { margin-bottom: var(--spacing-sm); }
.mb-2 { margin-bottom: var(--spacing-md); }
.mb-3 { margin-bottom: var(--spacing-lg); }
.mb-4 { margin-bottom: var(--spacing-xl); }

.hidden {
  display: none !important;
}

.visible {
  display: block !important;
}