/* ==========================================================================
   Base Design System & CSS Variables
   ========================================================================== */

:root {
  /* Fonts */
  --font-sans: 'Inter', system-ui, -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, Helvetica, Arial, sans-serif;
  --font-display: 'Outfit', var(--font-sans);
  --font-mono: 'Fira Code', monospace;

  /* Spacing */
  --spacing-xs: 0.25rem;
  --spacing-sm: 0.5rem;
  --spacing-md: 1rem;
  --spacing-lg: 1.5rem;
  --spacing-xl: 2.5rem;
  --spacing-xxl: 4rem;

  /* Layout */
  --container-max-width: 1200px;
  --header-height-normal: 90px;
  --header-height-shrunk: 65px;
  --border-radius-sm: 8px;
  --border-radius-md: 16px;
  --border-radius-lg: 24px;

  /* Transitions */
  --transition-fast: 0.2s cubic-bezier(0.16, 1, 0.3, 1);
  --transition-normal: 0.4s cubic-bezier(0.16, 1, 0.3, 1);
  --transition-slow: 0.8s cubic-bezier(0.16, 1, 0.3, 1);

  /* Light Theme Color Tokens */
  --bg-light: oklch(98% 0.01 240);
  --text-primary-light: oklch(25% 0.02 240);
  --text-secondary-light: oklch(45% 0.02 240);
  --accent-1-light: oklch(50% 0.24 260); /* Royal Indigo */
  --accent-2-light: oklch(58% 0.25 305); /* Magenta/Purple */
  --accent-hover-light: oklch(45% 0.24 260);
  --card-bg-light: rgba(255, 255, 255, 0.7);
  --card-border-light: rgba(0, 0, 0, 0.06);
  --card-shadow-light: 0 8px 30px rgba(0, 0, 0, 0.04);
  --glow-1-light: rgba(99, 102, 241, 0.08);
  --glow-2-light: rgba(168, 85, 247, 0.08);
  --header-bg-light: rgba(255, 255, 255, 0.75);

  /* Dark Theme Color Tokens */
  --bg-dark: oklch(14% 0.015 245); /* Rich Dark Charcoal */
  --text-primary-dark: oklch(93% 0.01 240);
  --text-secondary-dark: oklch(70% 0.02 240);
  --accent-1-dark: oklch(68% 0.2 250); /* Neon Indigo */
  --accent-2-dark: oklch(72% 0.2 295); /* Electric Violet */
  --accent-hover-dark: oklch(75% 0.18 250);
  --card-bg-dark: rgba(30, 41, 59, 0.45);
  --card-border-dark: rgba(255, 255, 255, 0.06);
  --card-shadow-dark: 0 8px 30px rgba(0, 0, 0, 0.2);
  --glow-1-dark: rgba(99, 102, 241, 0.2);
  --glow-2-dark: rgba(168, 85, 247, 0.2);
  --header-bg-dark: rgba(15, 23, 42, 0.75);

  /* Dynamic CSS Custom Properties (Modified by JavaScript attribute 'data-theme') */
  --bg: var(--bg-dark);
  --text-primary: var(--text-primary-dark);
  --text-secondary: var(--text-secondary-dark);
  --accent-1: var(--accent-1-dark);
  --accent-2: var(--accent-2-dark);
  --accent-hover: var(--accent-hover-dark);
  --card-bg: var(--card-bg-dark);
  --card-border: var(--card-border-dark);
  --card-shadow: var(--card-shadow-dark);
  --glow-1: var(--glow-1-dark);
  --glow-2: var(--glow-2-dark);
  --header-bg: var(--header-bg-dark);
  --selection-bg: oklch(65% 0.2 250 / 0.3);

  /* Set Browser Accent and Native Color Schemes */
  color-scheme: dark;
}

/* Light theme overrides */
html[data-theme="light"] {
  --bg: var(--bg-light);
  --text-primary: var(--text-primary-light);
  --text-secondary: var(--text-secondary-light);
  --accent-1: var(--accent-1-light);
  --accent-2: var(--accent-2-light);
  --accent-hover: var(--accent-hover-light);
  --card-bg: var(--card-bg-light);
  --card-border: var(--card-border-light);
  --card-shadow: var(--card-shadow-light);
  --glow-1: var(--glow-1-light);
  --glow-2: var(--glow-2-light);
  --header-bg: var(--header-bg-light);
  --selection-bg: oklch(50% 0.24 260 / 0.2);
  
  color-scheme: light;
}

/* Native System Color Match if user did not set preferences override */
@media (prefers-color-scheme: light) {
  :root:not([data-theme="dark"]) {
    --bg: var(--bg-light);
    --text-primary: var(--text-primary-light);
    --text-secondary: var(--text-secondary-light);
    --accent-1: var(--accent-1-light);
    --accent-2: var(--accent-2-light);
    --accent-hover: var(--accent-hover-light);
    --card-bg: var(--card-bg-light);
    --card-border: var(--card-border-light);
    --card-shadow: var(--card-shadow-light);
    --glow-1: var(--glow-1-light);
    --glow-2: var(--glow-2-light);
    --header-bg: var(--header-bg-light);
    --selection-bg: oklch(50% 0.24 260 / 0.2);

    color-scheme: light;
  }
}

/* Browser customizations */
::selection {
  background-color: var(--selection-bg);
}

html {
  scroll-behavior: smooth;
  accent-color: var(--accent-1);
}

body {
  margin: 0;
  padding: 0;
  background-color: var(--bg);
  color: var(--text-primary);
  font-family: var(--font-sans);
  line-height: 1.6;
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
  overflow-x: hidden;
  transition: background-color var(--transition-normal), color var(--transition-normal);
}

/* Scrollbar customizations */
:root {
  --scrollbar-thumb: light-dark(rgba(0, 0, 0, 0.15), rgba(255, 255, 255, 0.15));
  --scrollbar-track: transparent;
  scrollbar-color: var(--scrollbar-thumb) var(--scrollbar-track);
}

@supports not (scrollbar-color: auto) {
  ::-webkit-scrollbar {
    width: 10px;
    height: 10px;
  }
  ::-webkit-scrollbar-thumb {
    background: var(--scrollbar-thumb);
    border-radius: 5px;
    border: 2px solid var(--bg);
  }
  ::-webkit-scrollbar-track {
    background: var(--scrollbar-track);
  }
}

/* ==========================================================================
   Layout & Reusable Typography
   ========================================================================== */

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

section {
  padding: var(--spacing-xxl) 0;
  position: relative;
}

h1, h2, h3, h4, h5, h6 {
  font-family: var(--font-display);
  font-weight: 700;
  margin-top: 0;
  color: var(--text-primary);
}

.text-gradient {
  background: linear-gradient(135deg, var(--accent-1) 0%, var(--accent-2) 100%);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
  text-fill-color: transparent;
}

.section-title {
  font-size: clamp(2rem, 4vw, 3rem);
  text-align: center;
  margin-bottom: var(--spacing-xxl);
  position: relative;
}

.section-title::after {
  content: '';
  display: block;
  width: 60px;
  height: 4px;
  background: linear-gradient(135deg, var(--accent-1), var(--accent-2));
  margin: var(--spacing-sm) auto 0 auto;
  border-radius: 2px;
}

/* Glassmorphism utility */
.glass {
  background: var(--card-bg);
  backdrop-filter: blur(12px);
  -webkit-backdrop-filter: blur(12px);
  border: 1px solid var(--card-border);
  box-shadow: var(--card-shadow);
  border-radius: var(--border-radius-md);
  transition: transform var(--transition-normal), border-color var(--transition-normal), box-shadow var(--transition-normal);
}

.glass:hover {
  border-color: rgba(255, 255, 255, 0.15);
}

/* Buttons */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  padding: 0.8rem 1.6rem;
  border-radius: var(--border-radius-sm);
  font-family: var(--font-display);
  font-weight: 600;
  font-size: 0.95rem;
  text-decoration: none;
  cursor: pointer;
  transition: background-color var(--transition-fast), transform var(--transition-fast), border-color var(--transition-fast);
  border: none;
}

.btn-icon {
  width: 18px;
  height: 18px;
  margin-right: 0.5rem;
}

.btn-primary {
  background: linear-gradient(135deg, var(--accent-1) 0%, var(--accent-2) 100%);
  color: white;
}

.btn-primary:hover {
  transform: translateY(-2px);
  box-shadow: 0 8px 25px rgba(99, 102, 241, 0.3);
}

.btn-secondary {
  background: var(--card-bg);
  border: 1px solid var(--card-border);
  color: var(--text-primary);
  backdrop-filter: blur(8px);
}

.btn-secondary:hover {
  border-color: var(--accent-1);
  transform: translateY(-2px);
}

.btn-full {
  width: 100%;
}

.badge {
  display: inline-block;
  padding: 0.4rem 1rem;
  border-radius: 50px;
  font-size: 0.8rem;
  font-weight: 600;
  letter-spacing: 0.05em;
  text-transform: uppercase;
  background: linear-gradient(135deg, rgba(99, 102, 241, 0.1) 0%, rgba(168, 85, 247, 0.1) 100%);
  border: 1px solid rgba(99, 102, 241, 0.2);
  color: var(--accent-1);
  margin-bottom: var(--spacing-md);
}

/* Background Glow elements */
.ambient-glow {
  position: absolute;
  width: clamp(250px, 40vw, 550px);
  height: clamp(250px, 40vw, 550px);
  border-radius: 50%;
  filter: blur(100px);
  z-index: -1;
  pointer-events: none;
  opacity: 0.6;
}

.glow-1 {
  top: 5%;
  left: -5%;
  background: var(--glow-1);
  animation: float-glow-1 12s infinite alternate ease-in-out;
}

.glow-2 {
  top: 40%;
  right: -5%;
  background: var(--glow-2);
  animation: float-glow-2 15s infinite alternate ease-in-out;
}

@keyframes float-glow-1 {
  0% { transform: translate(0, 0) scale(1); }
  100% { transform: translate(50px, 30px) scale(1.1); }
}

@keyframes float-glow-2 {
  0% { transform: translate(0, 0) scale(1); }
  100% { transform: translate(-40px, -50px) scale(0.9); }
}

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

#main-header {
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  height: var(--header-height-normal);
  z-index: 1000;
  display: flex;
  align-items: center;
  transition: height var(--transition-normal), background-color var(--transition-normal), box-shadow var(--transition-normal);
  border-bottom: 1px solid transparent;
}

/* Header manual shrunk state (added by JS if CSS animations aren't supported) */
#main-header.shrunk {
  height: var(--header-height-shrunk);
  background-color: var(--header-bg);
  backdrop-filter: blur(16px);
  -webkit-backdrop-filter: blur(16px);
  border-bottom-color: var(--card-border);
  box-shadow: 0 4px 30px rgba(0, 0, 0, 0.05);
}

/* Native CSS Scroll-driven header shrink styling */
@supports ((animation-timeline: scroll()) and (animation-range: 0% 100%)) {
  @keyframes shrink-header {
    to {
      height: var(--header-height-shrunk);
      background-color: var(--header-bg);
      backdrop-filter: blur(16px);
      -webkit-backdrop-filter: blur(16px);
      border-bottom-color: var(--card-border);
      box-shadow: 0 4px 30px rgba(0, 0, 0, 0.05);
    }
  }

  #main-header {
    animation: shrink-header auto linear both;
    animation-timeline: scroll(block root);
    animation-range: 0px 100px;
  }
}

.header-container {
  display: flex;
  justify-content: space-between;
  align-items: center;
  width: 100%;
  max-width: var(--container-max-width);
  margin: 0 auto;
  padding: 0 var(--spacing-lg);
}

.logo {
  font-family: var(--font-display);
  font-weight: 800;
  font-size: 1.5rem;
  text-decoration: none;
  color: var(--text-primary);
  display: flex;
  align-items: center;
}

.logo-accent {
  color: var(--accent-1);
}

#nav-menu ul {
  display: flex;
  list-style: none;
  margin: 0;
  padding: 0;
  gap: var(--spacing-lg);
}

#nav-menu a {
  text-decoration: none;
  color: var(--text-secondary);
  font-family: var(--font-display);
  font-weight: 500;
  font-size: 0.95rem;
  transition: color var(--transition-fast);
  padding: var(--spacing-sm) 0;
  position: relative;
}

#nav-menu a:hover {
  color: var(--text-primary);
}

#nav-menu a::after {
  content: '';
  position: absolute;
  width: 0;
  height: 2px;
  bottom: 0;
  left: 0;
  background: linear-gradient(135deg, var(--accent-1), var(--accent-2));
  transition: width var(--transition-fast);
}

#nav-menu a:hover::after {
  width: 100%;
}

.header-actions {
  display: flex;
  align-items: center;
  gap: var(--spacing-md);
}

.theme-toggle-btn {
  background: var(--card-bg);
  border: 1px solid var(--card-border);
  border-radius: 50%;
  width: 42px;
  height: 42px;
  display: flex;
  align-items: center;
  justify-content: center;
  cursor: pointer;
  color: var(--text-primary);
  transition: background-color var(--transition-fast), border-color var(--transition-fast);
}

.theme-toggle-btn:hover {
  border-color: var(--accent-1);
}

.theme-toggle-btn svg {
  width: 20px;
  height: 20px;
}

/* Hide correct icon dynamically depending on the current theme */
.theme-toggle-btn .sun-icon {
  display: block;
}
.theme-toggle-btn .moon-icon {
  display: none;
}

html[data-theme="light"] .theme-toggle-btn .sun-icon {
  display: none;
}
html[data-theme="light"] .theme-toggle-btn .moon-icon {
  display: block;
}

@media (prefers-color-scheme: light) {
  :root:not([data-theme="dark"]) .theme-toggle-btn .sun-icon {
    display: none;
  }
  :root:not([data-theme="dark"]) .theme-toggle-btn .moon-icon {
    display: block;
  }
}

.menu-toggle {
  display: none;
  background: transparent;
  border: none;
  cursor: pointer;
  padding: var(--spacing-sm);
  z-index: 1100;
}

.hamburger {
  display: block;
  width: 24px;
  height: 2px;
  background-color: var(--text-primary);
  position: relative;
  transition: background-color var(--transition-fast);
}

.hamburger::before, .hamburger::after {
  content: '';
  position: absolute;
  width: 24px;
  height: 2px;
  background-color: var(--text-primary);
  left: 0;
  transition: transform var(--transition-fast), top var(--transition-fast);
}

.hamburger::before { top: -6px; }
.hamburger::after { top: 6px; }

/* Hamburger transform when mobile menu expanded */
.menu-toggle[aria-expanded="true"] .hamburger {
  background-color: transparent;
}
.menu-toggle[aria-expanded="true"] .hamburger::before {
  top: 0;
  transform: rotate(45deg);
}
.menu-toggle[aria-expanded="true"] .hamburger::after {
  top: 0;
  transform: rotate(-45deg);
}

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

.hero-section {
  padding-top: calc(var(--header-height-normal) + var(--spacing-xl));
  min-height: 90vh;
  display: flex;
  align-items: center;
}

.hero-container {
  display: grid;
  grid-template-columns: 1.2fr 0.8fr;
  gap: var(--spacing-xxl);
  align-items: center;
}

.hero-content h1 {
  font-size: clamp(2.5rem, 6vw, 4.5rem);
  line-height: 1.1;
  margin-bottom: var(--spacing-sm);
  letter-spacing: -0.02em;
}

.hero-content h2 {
  font-size: clamp(1.5rem, 3.5vw, 2.25rem);
  font-weight: 500;
  margin-bottom: var(--spacing-lg);
  color: var(--text-secondary);
}

.role-dynamic {
  color: var(--accent-1);
}

.cursor {
  font-weight: 300;
  animation: blink 1s step-end infinite;
  color: var(--accent-1);
}

@keyframes blink {
  from, to { opacity: 0; }
  50% { opacity: 1; }
}

.hero-lead {
  font-size: clamp(1rem, 2vw, 1.2rem);
  color: var(--text-secondary);
  margin-bottom: var(--spacing-xl);
  max-width: 580px;
}

.hero-actions {
  display: flex;
  gap: var(--spacing-md);
  margin-bottom: var(--spacing-xl);
}

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

.social-links a {
  color: var(--text-secondary);
  transition: color var(--transition-fast), transform var(--transition-fast);
}

.social-links a:hover {
  color: var(--accent-1);
  transform: translateY(-2px);
}

/* Visual code card element in Hero */
.hero-visual {
  display: flex;
  justify-content: center;
  position: relative;
}

.visual-card-wrapper {
  position: relative;
  width: 100%;
  max-width: 420px;
}

.visual-card {
  width: 100%;
  font-size: 0.9rem;
  overflow: hidden;
  border-radius: var(--border-radius-md);
  box-shadow: var(--card-shadow);
  border: 1px solid var(--card-border);
}

.card-header {
  background: rgba(0, 0, 0, 0.15);
  padding: var(--spacing-sm) var(--spacing-md);
  display: flex;
  align-items: center;
  gap: 6px;
  border-bottom: 1px solid var(--card-border);
}

.dot {
  width: 11px;
  height: 11px;
  border-radius: 50%;
}
.dot.red { background-color: #ef4444; }
.dot.yellow { background-color: #f59e0b; }
.dot.green { background-color: #10b981; }

.card-title {
  font-family: var(--font-mono);
  font-size: 0.75rem;
  color: var(--text-secondary);
  margin-left: var(--spacing-sm);
}

.card-body {
  padding: var(--spacing-lg);
  font-family: var(--font-mono);
  white-space: pre;
  overflow-x: auto;
  line-height: 1.6;
}

.code-keyword { color: #f472b6; }
.code-string { color: #34d399; }
.code-number { color: #fbbf24; }

.glow-sphere {
  position: absolute;
  width: 200px;
  height: 200px;
  background: radial-gradient(circle, var(--accent-1) 0%, transparent 70%);
  opacity: 0.15;
  filter: blur(20px);
  bottom: -40px;
  right: -40px;
  z-index: -1;
}

/* ==========================================================================
   About & Skills Section
   ========================================================================== */

.about-grid {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: var(--spacing-xxl);
  align-items: start;
}

.about-text p {
  color: var(--text-secondary);
  font-size: 1.05rem;
  margin-bottom: var(--spacing-lg);
}

.core-values {
  display: grid;
  grid-template-columns: 1fr;
  gap: var(--spacing-lg);
  margin-top: var(--spacing-xl);
}

.value-item {
  display: grid;
  grid-template-columns: 40px 1fr;
  gap: var(--spacing-sm);
  align-items: start;
}

.value-icon {
  font-size: 1.5rem;
  grid-row: span 2;
}

.value-item h3 {
  font-size: 1.1rem;
  margin: 0 0 var(--spacing-xs) 0;
}

.value-item p {
  font-size: 0.9rem;
  margin: 0;
}

/* Technical Expertise Accordions */
.skills-wrapper h3 {
  font-size: 1.4rem;
  margin-bottom: var(--spacing-xs);
}

.skills-subtitle {
  font-size: 0.9rem;
  color: var(--text-secondary);
  margin-bottom: var(--spacing-lg);
}

.skills-accordion {
  display: flex;
  flex-direction: column;
  gap: var(--spacing-md);
}

.skills-group {
  padding: 0;
  overflow: hidden;
  border-radius: var(--border-radius-sm);
}

/* Remove default arrows */
.skills-group summary {
  list-style: none;
  cursor: pointer;
  padding: var(--spacing-md);
  font-family: var(--font-display);
  font-weight: 600;
  font-size: 1.05rem;
  display: flex;
  justify-content: space-between;
  align-items: center;
  user-select: none;
}

.skills-group summary::-webkit-details-marker {
  display: none;
}

.accordion-icon {
  transition: transform var(--transition-fast);
  font-size: 1.2rem;
  font-weight: 400;
}

.skills-group[open] .accordion-icon {
  transform: rotate(45deg);
}

.skills-group-content {
  padding: 0 var(--spacing-md) var(--spacing-md) var(--spacing-md);
  display: flex;
  flex-wrap: wrap;
  gap: var(--spacing-sm);
}

.skill-pill {
  background: var(--card-bg);
  border: 1px solid var(--card-border);
  padding: 0.4rem 0.9rem;
  border-radius: 50px;
  font-size: 0.85rem;
  font-weight: 500;
  color: var(--text-secondary);
  transition: border-color var(--transition-fast), color var(--transition-fast), background-color var(--transition-fast);
}

.skill-pill:hover {
  border-color: var(--accent-1);
  color: var(--text-primary);
  background-color: rgba(99, 102, 241, 0.05);
}

/* ==========================================================================
   Experience Section
   ========================================================================== */

.timeline {
  position: relative;
  max-width: 900px;
  margin: 0 auto;
  padding: var(--spacing-lg) 0;
}

/* Vertical center track line */
.timeline::before {
  content: '';
  position: absolute;
  width: 2px;
  background: linear-gradient(180deg, var(--accent-1) 0%, var(--accent-2) 100%);
  top: 0;
  bottom: 0;
  left: 32px;
}

.timeline-item {
  position: relative;
  margin-bottom: var(--spacing-xl);
  padding-left: 70px;
}

.timeline-dot {
  position: absolute;
  width: 14px;
  height: 14px;
  border-radius: 50%;
  background: var(--accent-1);
  left: 26px;
  top: 24px;
  box-shadow: 0 0 10px var(--accent-1);
  border: 3px solid var(--bg);
  transition: transform var(--transition-fast);
}

.timeline-item:hover .timeline-dot {
  transform: scale(1.3);
}

.timeline-date {
  font-family: var(--font-display);
  font-weight: 700;
  font-size: 1rem;
  color: var(--accent-1);
  margin-bottom: var(--spacing-xs);
}

.timeline-card {
  padding: var(--spacing-lg);
}

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

.timeline-header h3 {
  font-size: 1.25rem;
  margin: 0;
}

.timeline-location {
  font-size: 0.85rem;
  color: var(--text-secondary);
}

.role-desc {
  color: var(--text-secondary);
  font-size: 0.95rem;
  margin-top: 0;
  margin-bottom: var(--spacing-md);
}

/* Clickable details accordion in timeline card */
.timeline-details {
  border-top: 1px solid var(--card-border);
  margin-top: var(--spacing-md);
  padding-top: var(--spacing-md);
}

.timeline-details summary {
  list-style: none;
  cursor: pointer;
  outline: none;
  display: inline-flex;
  align-items: center;
  gap: 6px;
  user-select: none;
}

.timeline-details summary::-webkit-details-marker {
  display: none;
}

.btn-text {
  font-family: var(--font-display);
  font-size: 0.85rem;
  font-weight: 600;
  color: var(--accent-1);
  transition: color var(--transition-fast);
}

.btn-text:hover {
  color: var(--accent-hover);
}

.arrow-icon {
  width: 14px;
  height: 14px;
  transition: transform var(--transition-normal);
}

.timeline-details[open] .arrow-icon {
  transform: rotate(180deg);
}

.achievements-list {
  margin: var(--spacing-md) 0 0 0;
  padding-left: var(--spacing-lg);
  display: flex;
  flex-direction: column;
  gap: var(--spacing-xs);
}

.achievements-list li {
  font-size: 0.9rem;
  color: var(--text-secondary);
}

/* ==========================================================================
   Projects Section
   ========================================================================== */

.project-filters {
  display: flex;
  justify-content: center;
  gap: var(--spacing-sm);
  margin-bottom: var(--spacing-xl);
}

.filter-tab {
  background: var(--card-bg);
  border: 1px solid var(--card-border);
  color: var(--text-secondary);
  padding: 0.5rem 1.2rem;
  border-radius: 50px;
  font-family: var(--font-display);
  font-weight: 500;
  font-size: 0.9rem;
  cursor: pointer;
  transition: background-color var(--transition-fast), color var(--transition-fast), border-color var(--transition-fast);
}

.filter-tab:hover {
  color: var(--text-primary);
  border-color: var(--accent-1);
}

.filter-tab.active {
  background: linear-gradient(135deg, var(--accent-1), var(--accent-2));
  color: white;
  border-color: transparent;
}

.projects-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(280px, 1fr));
  gap: var(--spacing-lg);
}

.project-card {
  display: flex;
  flex-direction: column;
  height: 100%;
  overflow: hidden;
}

.project-card:hover {
  transform: translateY(-4px);
  box-shadow: var(--card-shadow);
}

.project-image-placeholder {
  height: 160px;
  background: linear-gradient(135deg, rgba(99, 102, 241, 0.05) 0%, rgba(168, 85, 247, 0.05) 100%);
  display: flex;
  align-items: center;
  justify-content: center;
  position: relative;
  border-bottom: 1px solid var(--card-border);
}

.project-icon {
  font-size: 3rem;
  z-index: 2;
  transition: transform var(--transition-normal);
}

.project-card:hover .project-icon {
  transform: scale(1.15);
}

.image-overlay {
  position: absolute;
  top: 0;
  left: 0;
  width: 100%;
  height: 100%;
  background: linear-gradient(180deg, transparent 40%, rgba(0, 0, 0, 0.3) 100%);
  z-index: 1;
}

.project-info {
  padding: var(--spacing-lg);
  display: flex;
  flex-direction: column;
  flex-grow: 1;
}

.project-meta {
  font-size: 0.75rem;
  font-weight: 600;
  text-transform: uppercase;
  color: var(--accent-1);
  letter-spacing: 0.05em;
  margin-bottom: var(--spacing-xs);
}

.project-info h3 {
  font-size: 1.25rem;
  margin-bottom: var(--spacing-sm);
}

.project-info p {
  color: var(--text-secondary);
  font-size: 0.9rem;
  margin-top: 0;
  margin-bottom: var(--spacing-md);
  flex-grow: 1;
}

.project-tech {
  display: flex;
  flex-wrap: wrap;
  gap: 6px;
  margin-bottom: var(--spacing-lg);
}

.project-tech span {
  font-family: var(--font-mono);
  font-size: 0.75rem;
  padding: 0.2rem 0.6rem;
  border-radius: 4px;
  background: rgba(99, 102, 241, 0.05);
  border: 1px solid rgba(99, 102, 241, 0.1);
  color: var(--text-secondary);
}

.project-links {
  display: flex;
  gap: var(--spacing-md);
  margin-top: auto;
}

.link-btn {
  display: inline-flex;
  align-items: center;
  gap: 4px;
  font-family: var(--font-display);
  font-weight: 600;
  font-size: 0.85rem;
  color: var(--text-primary);
  text-decoration: none;
  transition: color var(--transition-fast);
}

.link-btn:hover {
  color: var(--accent-1);
}

/* ==========================================================================
   Contact Section
   ========================================================================== */

.contact-grid {
  display: grid;
  grid-template-columns: 0.9fr 1.1fr;
  gap: var(--spacing-xxl);
  align-items: start;
}

.contact-info h3 {
  font-size: 1.5rem;
  margin-bottom: var(--spacing-md);
}

.contact-info p {
  color: var(--text-secondary);
  font-size: 1.05rem;
  margin-bottom: var(--spacing-xl);
}

.contact-methods {
  display: flex;
  flex-direction: column;
  gap: var(--spacing-lg);
}

.contact-method-item {
  display: grid;
  grid-template-columns: 48px 1fr;
  gap: var(--spacing-sm);
  align-items: center;
}

.contact-icon {
  width: 40px;
  height: 40px;
  border-radius: 50%;
  background: var(--card-bg);
  border: 1px solid var(--card-border);
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 1.2rem;
}

.contact-method-item h4 {
  font-size: 0.85rem;
  margin: 0;
  text-transform: uppercase;
  letter-spacing: 0.05em;
  color: var(--text-secondary);
}

.contact-link {
  color: var(--text-primary);
  text-decoration: none;
  font-weight: 500;
  transition: color var(--transition-fast);
}

.contact-link:hover {
  color: var(--accent-1);
}

.contact-form-wrapper {
  padding: var(--spacing-xl);
}

.contact-form {
  display: flex;
  flex-direction: column;
  gap: var(--spacing-md);
}

.form-row {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: var(--spacing-md);
}

.form-group {
  display: flex;
  flex-direction: column;
  gap: var(--spacing-xs);
  position: relative;
}

.form-group label {
  font-family: var(--font-display);
  font-weight: 600;
  font-size: 0.85rem;
  color: var(--text-secondary);
}

.form-group input,
.form-group textarea {
  background: rgba(0, 0, 0, 0.15);
  border: 1px solid var(--card-border);
  color: var(--text-primary);
  padding: 0.8rem 1rem;
  border-radius: var(--border-radius-sm);
  font-family: var(--font-sans);
  font-size: 0.95rem;
  transition: border-color var(--transition-fast), background-color var(--transition-fast);
}

.form-group input:focus,
.form-group textarea:focus {
  outline: none;
  border-color: var(--accent-1);
  background: rgba(0, 0, 0, 0.25);
}

/* User inputs validation feedback styling */
.form-group input:user-invalid,
.form-group textarea:user-invalid {
  border-color: #ef4444;
}

.error-msg {
  display: none;
  font-size: 0.75rem;
  color: #f87171;
  margin-top: 2px;
}

.form-group input:user-invalid ~ .error-msg,
.form-group textarea:user-invalid ~ .error-msg {
  display: block;
}

/* Loading button spinner */
#submit-btn {
  position: relative;
  overflow: hidden;
}

.spinner {
  display: none;
  width: 20px;
  height: 20px;
  border: 2px solid rgba(255, 255, 255, 0.3);
  border-radius: 50%;
  border-top-color: white;
  animation: spin 0.8s linear infinite;
  position: absolute;
}

@keyframes spin {
  to { transform: rotate(360deg); }
}

#submit-btn.loading .btn-text-content {
  opacity: 0;
}
#submit-btn.loading .spinner {
  display: block;
}

.form-feedback {
  font-size: 0.9rem;
  font-weight: 500;
  text-align: center;
  padding: var(--spacing-sm);
  border-radius: var(--border-radius-sm);
  display: none;
}

.form-feedback.success {
  display: block;
  background: rgba(16, 185, 129, 0.1);
  border: 1px solid rgba(16, 185, 129, 0.2);
  color: #34d399;
}

.form-feedback.error {
  display: block;
  background: rgba(239, 68, 68, 0.1);
  border: 1px solid rgba(239, 68, 68, 0.2);
  color: #f87171;
}

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

.main-footer {
  border-top: 1px solid var(--card-border);
  padding: var(--spacing-xl) 0;
  background: rgba(0, 0, 0, 0.1);
}

.footer-container {
  display: flex;
  justify-content: space-between;
  align-items: center;
  flex-wrap: wrap;
  gap: var(--spacing-md);
}

.main-footer p {
  color: var(--text-secondary);
  font-size: 0.9rem;
  margin: 0;
}

.footer-meta {
  font-size: 0.8rem !important;
}

/* ==========================================================================
   Animations & Responsive Media Queries
   ========================================================================== */

/* Standard entry reveals (for non-CSS-scroll supported browsers) */
.scroll-reveal {
  opacity: 0;
  transform: translateY(30px);
  transition: opacity var(--transition-slow), transform var(--transition-slow);
}

.scroll-reveal.visible {
  opacity: 1;
  transform: translateY(0);
}

/* Native CSS Scroll Reveal logic - overrides manual JS class reveal */
@media (prefers-reduced-motion: no-preference) {
  @supports ((animation-timeline: view()) and (animation-range: entry)) {
    @keyframes reveal-in {
      from {
        opacity: 0;
        transform: translateY(45px) scale(0.96);
      }
      to {
        opacity: 1;
        transform: translateY(0) scale(1);
      }
    }
    
    .scroll-reveal {
      animation: reveal-in auto linear both;
      animation-timeline: view();
      animation-range: entry 5% entry 35%;
      opacity: 1;
      transform: none;
      transition: none;
    }
  }
}

/* Tablet (Portrait) Breakpoint */
@media (max-width: 900px) {
  :root {
    --spacing-xxl: 2.5rem;
  }

  .hero-container {
    grid-template-columns: 1fr;
    gap: var(--spacing-xl);
    text-align: center;
  }

  .hero-lead {
    margin-left: auto;
    margin-right: auto;
  }

  .hero-actions {
    justify-content: center;
  }

  .social-links {
    justify-content: center;
  }

  .hero-visual {
    order: -1;
  }

  .about-grid {
    grid-template-columns: 1fr;
    gap: var(--spacing-xl);
  }

  .contact-grid {
    grid-template-columns: 1fr;
    gap: var(--spacing-xl);
  }

  /* Adjust timeline track line */
  .timeline::before {
    left: 20px;
  }
  .timeline-item {
    padding-left: 45px;
  }
  .timeline-dot {
    left: 14px;
  }
  .timeline-date {
    position: static;
    margin-bottom: var(--spacing-sm);
  }
}

/* Mobile Breakpoint */
@media (max-width: 600px) {
  :root {
    --spacing-lg: 1rem;
    --spacing-xl: 1.5rem;
  }

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

  /* Hamburger Menu implementation */
  .menu-toggle {
    display: block;
  }

  #nav-menu {
    position: absolute;
    top: 100%;
    left: 0;
    right: 0;
    background: var(--header-bg);
    border-bottom: 1px solid var(--card-border);
    backdrop-filter: blur(20px);
    -webkit-backdrop-filter: blur(20px);
    padding: var(--spacing-lg) 0;
    opacity: 0;
    visibility: hidden;
    transform: translateY(-10px);
    transition: opacity var(--transition-normal), transform var(--transition-normal), visibility var(--transition-normal);
  }

  #nav-menu.active {
    opacity: 1;
    visibility: visible;
    transform: translateY(0);
  }

  #nav-menu ul {
    flex-direction: column;
    align-items: center;
    gap: var(--spacing-md);
  }

  .form-row {
    grid-template-columns: 1fr;
  }

  .timeline-header {
    flex-direction: column;
    align-items: flex-start;
  }

  .footer-container {
    flex-direction: column;
    text-align: center;
  }
}

/* ==========================================================================
   Print Style Optimization (CMD+P / Resume PDF generation)
   ========================================================================== */

@media print {
  body {
    background: white !important;
    color: black !important;
    font-size: 10pt;
  }

  :root {
    --text-primary: black !important;
    --text-secondary: #444 !important;
    --accent-1: #1e3a8a !important; /* Professional dark blue */
    --accent-2: #2563eb !important;
  }

  /* Hide digital-only interactive/redundant nodes */
  #main-header,
  .ambient-glow,
  .hero-actions,
  .social-links,
  .theme-toggle-btn,
  .project-filters,
  .contact-section,
  .main-footer,
  .badge,
  .glow-sphere,
  .skills-subtitle,
  .btn-text {
    display: none !important;
  }

  /* Force display of expanded elements for print documentation */
  details {
    display: block !important;
  }
  details[class*="skills-group"] {
    border: none !important;
    background: transparent !important;
    box-shadow: none !important;
    margin-bottom: var(--spacing-sm) !important;
  }
  details[class*="skills-group"] summary {
    padding: 0 !important;
    font-size: 11pt !important;
    border-bottom: 1px solid #ccc !important;
    margin-bottom: var(--spacing-xs) !important;
    cursor: default !important;
  }
  details[class*="skills-group"] summary .accordion-icon {
    display: none !important;
  }
  .skills-group-content {
    padding: 0 !important;
    gap: 4px !important;
  }
  .skill-pill {
    background: #f3f4f6 !important;
    border: 1px solid #ccc !important;
    color: black !important;
    padding: 2px 6px !important;
    font-size: 8pt !important;
  }

  /* Timeline formatting */
  .timeline::before {
    display: none !important;
  }
  .timeline-item {
    padding-left: 0 !important;
    margin-bottom: var(--spacing-lg) !important;
    page-break-inside: avoid;
  }
  .timeline-dot {
    display: none !important;
  }
  .timeline-card {
    border: none !important;
    background: transparent !important;
    box-shadow: none !important;
    padding: 0 !important;
  }
  .timeline-details {
    border-top: none !important;
    margin-top: 4px !important;
    padding-top: 0 !important;
  }
  .timeline-details[class] {
    display: block !important;
  }
  .achievements-list {
    display: flex !important;
    margin-top: 4px !important;
  }

  /* Project Grid Print formatting */
  .projects-section {
    page-break-before: always;
  }
  .projects-grid {
    grid-template-columns: 1fr 1fr !important;
    gap: var(--spacing-md) !important;
  }
  .project-card {
    border: 1px solid #ccc !important;
    background: transparent !important;
    box-shadow: none !important;
    page-break-inside: avoid;
  }
  .project-image-placeholder,
  .project-links {
    display: none !important;
  }
  .project-info {
    padding: var(--spacing-sm) !important;
  }

  section {
    padding: var(--spacing-lg) 0 !important;
  }

  .container {
    max-width: 100% !important;
    padding: 0 !important;
  }

  .hero-section {
    min-height: auto !important;
    padding-top: var(--spacing-lg) !important;
  }
  .hero-container {
    grid-template-columns: 1fr !important;
  }
  .hero-visual {
    display: none !important;
  }
}