/* ========================================
   CSS Variables & Reset
   ======================================== */
:root {
  /* Colors - Blue Professional Palette */
  --brand-50: #eff6ff;
  --brand-100: #dbeafe;
  --brand-200: #bfdbfe;
  --brand-300: #93c5fd;
  --brand-400: #60a5fa;
  --brand-500: #3b82f6;
  --brand-600: #2563eb;
  --brand-700: #1d4ed8;
  --brand-800: #1e40af;
  --brand-900: #1e3a8a;

  /* Semantic Colors */
  --fg: #111827;
  --fg-muted: #6b7280;
  --fg-subtle: #9ca3af;
  --fg-inverse: #ffffff;

  --bg: #ffffff;
  --bg-muted: #f9fafb;
  --bg-subtle: #f3f4f6;
  --bg-card: #ffffff;

  --border: #e5e7eb;
  --border-strong: #d1d5db;
  --border-focus: #3b82f6;

  /* Shadows */
  --shadow-sm: 0 1px 2px 0 rgba(0, 0, 0, 0.05);
  --shadow: 0 4px 6px -1px rgba(0, 0, 0, 0.1), 0 2px 4px -2px rgba(0, 0, 0, 0.1);
  --shadow-md: 0 10px 15px -3px rgba(0, 0, 0, 0.1), 0 4px 6px -4px rgba(0, 0, 0, 0.1);
  --shadow-lg: 0 20px 25px -5px rgba(0, 0, 0, 0.1), 0 8px 10px -6px rgba(0, 0, 0, 0.1);

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

  /* Spacing */
  --space-1: 0.25rem;
  --space-2: 0.5rem;
  --space-3: 0.75rem;
  --space-4: 1rem;
  --space-5: 1.25rem;
  --space-6: 1.5rem;
  --space-8: 2rem;
  --space-10: 2.5rem;
  --space-12: 3rem;
  --space-16: 4rem;

  /* Typography */
  --font-sans: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, sans-serif;
  --font-heading: 'Space Grotesk', var(--font-sans);

  --text-xs: 0.75rem;
  --text-sm: 0.875rem;
  --text-base: 1rem;
  --text-lg: 1.125rem;
  --text-xl: 1.25rem;
  --text-2xl: 1.5rem;
  --text-3xl: 1.875rem;
  --text-4xl: 2.25rem;

  --leading-tight: 1.25;
  --leading-normal: 1.5;
  --leading-relaxed: 1.75;

  /* Layout */
  --sidebar-width: 280px;
  --header-height: 72px;
  --max-width: 1200px;
  --container-padding: 1.5rem;

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

  /* Z-index */
  --z-dropdown: 100;
  --z-sticky: 200;
  --z-fixed: 300;
  --z-modal: 400;
  --z-toast: 500;
}

/* Dark Mode */
@media (prefers-color-scheme: dark) {
  :root {
    --brand-50: #1e3a8a;
    --brand-100: #1e40af;
    --brand-200: #1d4ed8;
    --brand-300: #2563eb;
    --brand-400: #3b82f6;
    --brand-500: #60a5fa;
    --brand-600: #93c5fd;
    --brand-700: #bfdbfe;
    --brand-800: #dbeafe;
    --brand-900: #eff6ff;

    --fg: #f9fafb;
    --fg-muted: #9ca3af;
    --fg-subtle: #6b7280;
    --fg-inverse: #111827;

    --bg: #0f172a;
    --bg-muted: #1e293b;
    --bg-subtle: #334155;
    --bg-card: #1e293b;

    --border: #334155;
    --border-strong: #475569;
    --border-focus: #60a5fa;

    --shadow-sm: 0 1px 2px 0 rgba(0, 0, 0, 0.3);
    --shadow: 0 4px 6px -1px rgba(0, 0, 0, 0.4), 0 2px 4px -2px rgba(0, 0, 0, 0.3);
    --shadow-md: 0 10px 15px -3px rgba(0, 0, 0, 0.4), 0 4px 6px -4px rgba(0, 0, 0, 0.3);
    --shadow-lg: 0 20px 25px -5px rgba(0, 0, 0, 0.4), 0 8px 10px -6px rgba(0, 0, 0, 0.3);
  }
}

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

* {
  margin: 0;
  padding: 0;
}

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;
    animation-iteration-count: 1 !important;
    transition-duration: 0.01ms !important;
  }
}

body {
  font-family: var(--font-sans);
  font-size: var(--text-base);
  line-height: var(--leading-normal);
  color: var(--fg);
  background: var(--bg);
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
}

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

a {
  color: inherit;
  text-decoration: none;
}

button {
  font: inherit;
  background: none;
  border: none;
  cursor: pointer;
}

ul, ol {
  list-style: none;
}

:focus-visible {
  outline: 2px solid var(--border-focus);
  outline-offset: 2px;
}

.skip-link {
  position: absolute;
  top: -100%;
  left: 50%;
  transform: translateX(-50%);
  padding: var(--space-3) var(--space-4);
  background: var(--brand-600);
  color: var(--fg-inverse);
  border-radius: var(--radius);
  z-index: var(--z-toast);
  font-weight: 500;
}
.skip-link:focus { top: var(--space-4); }

/* ========================================
   Layout
   ======================================== */
.container {
  width: 100%;
  max-width: var(--max-width);
  margin: 0 auto;
  padding: 0 var(--container-padding);
}

.site-header {
  position: sticky;
  top: 0;
  z-index: var(--z-sticky);
  background: var(--bg);
  border-bottom: 1px solid var(--border);
  backdrop-filter: blur(8px);
  background: rgba(var(--bg-rgb, 255, 255, 255), 0.9);
}

@supports not (backdrop-filter: blur(8px)) {
  .site-header { background: var(--bg); }
}

.nav {
  display: flex;
  align-items: center;
  justify-content: space-between;
  height: var(--header-height);
  gap: var(--space-4);
}

.nav-logo {
  font-family: var(--font-heading);
  font-size: var(--text-xl);
  font-weight: 700;
  color: var(--brand-600);
  flex-shrink: 0;
}

.nav-menu {
  display: flex;
  align-items: center;
  gap: var(--space-1);
}

.nav-link {
  display: block;
  padding: var(--space-2) var(--space-3);
  font-size: var(--text-sm);
  font-weight: 500;
  color: var(--fg-muted);
  border-radius: var(--radius);
  transition: color var(--transition-fast), background var(--transition-fast);
}

.nav-link:hover,
.nav-link.active {
  color: var(--brand-600);
  background: var(--brand-50);
}

.nav-toggle {
  display: none;
  width: 44px;
  height: 44px;
  align-items: center;
  justify-content: center;
  border-radius: var(--radius);
  color: var(--fg);
}

.hamburger {
  position: relative;
  width: 24px;
  height: 2px;
  background: currentColor;
  border-radius: 2px;
  transition: background var(--transition-fast);
}
.hamburger::before,
.hamburger::after {
  content: "";
  position: absolute;
  left: 0;
  width: 100%;
  height: 2px;
  background: currentColor;
  border-radius: 2px;
  transition: transform var(--transition-fast);
}
.hamburger::before { top: -7px; }
.hamburger::after { bottom: -7px; }

.nav-toggle[aria-expanded="true"] .hamburger { background: transparent; }
.nav-toggle[aria-expanded="true"] .hamburger::before { transform: rotate(45deg) translate(5px, 5px); }
.nav-toggle[aria-expanded="true"] .hamburger::after { transform: rotate(-45deg) translate(5px, -5px); }

.main-layout {
  display: grid;
  grid-template-columns: var(--sidebar-width) 1fr;
  gap: var(--space-8);
  padding: var(--space-8) 0;
}

.sidebar {
  position: sticky;
  top: calc(var(--header-height) + var(--space-6));
  max-height: calc(100vh - var(--header-height) - var(--space-6) * 2);
  overflow-y: auto;
  padding-right: var(--space-4);
}

.main-content { min-width: 0; }

/* ========================================
   Sidebar Cards
   ======================================== */
.sidebar-card {
  background: var(--bg-card);
  border: 1px solid var(--border);
  border-radius: var(--radius-lg);
  padding: var(--space-5);
  margin-bottom: var(--space-5);
  box-shadow: var(--shadow-sm);
}

.sidebar-title {
  font-family: var(--font-heading);
  font-size: var(--text-sm);
  font-weight: 600;
  text-transform: uppercase;
  letter-spacing: 0.05em;
  color: var(--fg-subtle);
  margin-bottom: var(--space-4);
}

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

.avatar-wrapper {
  position: relative;
  width: 120px;
  height: 120px;
  margin: 0 auto var(--space-4);
  border-radius: 50%;
  overflow: hidden;
  border: 4px solid var(--brand-100);
  background: var(--brand-100);
}

.avatar {
  width: 100%;
  height: 100%;
  object-fit: cover;
}

.avatar-fallback {
  position: absolute;
  inset: 0;
  display: flex;
  align-items: center;
  justify-content: center;
  font-family: var(--font-heading);
  font-size: var(--text-2xl);
  font-weight: 700;
  color: var(--brand-600);
  background: var(--brand-50);
}

.profile-name {
  font-family: var(--font-heading);
  font-size: var(--text-xl);
  font-weight: 700;
  color: var(--fg);
  margin-bottom: var(--space-1);
}

.profile-title {
  font-size: var(--text-sm);
  color: var(--brand-600);
  font-weight: 500;
  margin-bottom: var(--space-1);
}

.profile-location {
  font-size: var(--text-sm);
  color: var(--fg-muted);
}

/* Contact List */
.contact-list { display: flex; flex-direction: column; gap: var(--space-3); }
.contact-link {
  display: flex;
  align-items: center;
  gap: var(--space-3);
  padding: var(--space-2) var(--space-3);
  font-size: var(--text-sm);
  color: var(--fg-muted);
  border-radius: var(--radius);
  transition: all var(--transition-fast);
}
.contact-link:hover {
  color: var(--brand-600);
  background: var(--brand-50);
}
.contact-link .icon { width: 18px; height: 18px; flex-shrink: 0; color: var(--fg-subtle); }
.contact-link:hover .icon { color: var(--brand-600); }

/* Skills Bars */
.skills-bars { display: flex; flex-direction: column; gap: var(--space-4); }
.skill-bar {
  display: grid;
  grid-template-columns: auto 1fr;
  gap: var(--space-3);
  align-items: center;
}
.skill-name {
  font-size: var(--text-sm);
  font-weight: 500;
  color: var(--fg);
  white-space: nowrap;
  min-width: 80px;
}
.skill-track {
  height: 6px;
  background: var(--bg-subtle);
  border-radius: var(--radius-full);
  overflow: hidden;
}
.skill-fill {
  height: 100%;
  background: linear-gradient(90deg, var(--brand-500), var(--brand-400));
  border-radius: var(--radius-full);
  width: 0;
  transition: width 1s ease-out 0.3s;
}
.skill-value {
  font-size: var(--text-xs);
  font-weight: 600;
  color: var(--fg-muted);
  min-width: 36px;
  text-align: right;
}

/* Languages */
.languages-list { display: flex; flex-direction: column; gap: var(--space-3); }
.lang-item {
  display: flex;
  justify-content: space-between;
  align-items: center;
  padding: var(--space-2) var(--space-3);
  background: var(--bg-muted);
  border-radius: var(--radius);
}
.lang-name { font-size: var(--text-sm); font-weight: 500; color: var(--fg); }
.lang-level { font-size: var(--text-xs); color: var(--fg-muted); background: var(--bg-subtle); padding: var(--space-1) var(--space-2); border-radius: var(--radius-full); }

/* Interests */
.interests-list { display: flex; flex-wrap: wrap; gap: var(--space-2); }
.interest-tag {
  font-size: var(--text-xs);
  font-weight: 500;
  color: var(--fg-muted);
  background: var(--bg-muted);
  padding: var(--space-1) var(--space-3);
  border-radius: var(--radius-full);
  border: 1px solid var(--border);
}

/* ========================================
   Main Content Sections
   ======================================== */
.section { margin-bottom: var(--space-10); }
.section-title {
  font-family: var(--font-heading);
  font-size: var(--text-xl);
  font-weight: 700;
  color: var(--fg);
  margin-bottom: var(--space-6);
  padding-bottom: var(--space-3);
  border-bottom: 2px solid var(--brand-100);
  position: relative;
}
.section-title::after {
  content: "";
  position: absolute;
  bottom: -2px;
  left: 0;
  width: 60px;
  height: 2px;
  background: var(--brand-600);
}

.section-content { animation: fadeInUp 0.6s ease forwards; }

/* Profile */
.profile-text { font-size: var(--text-base); line-height: var(--leading-relaxed); color: var(--fg-muted); }

/* Objective */
.objective-card {
  background: var(--brand-50);
  border: 1px solid var(--brand-100);
  border-radius: var(--radius-lg);
  padding: var(--space-6);
}
.objective-text { font-size: var(--text-base); line-height: var(--leading-relaxed); color: var(--fg); }

/* Timeline / Experience */
.timeline {
  position: relative;
  padding-left: var(--space-6);
}
.timeline::before {
  content: "";
  position: absolute;
  left: 0;
  top: 0;
  bottom: 0;
  width: 2px;
  background: linear-gradient(180deg, var(--brand-300), var(--brand-100));
  border-radius: 2px;
}

.timeline-item {
  position: relative;
  padding-bottom: var(--space-8);
}
.timeline-item:last-child { padding-bottom: 0; }

.timeline-marker {
  position: absolute;
  left: -6px;
  top: 0;
  width: 14px;
  height: 14px;
  background: var(--brand-600);
  border: 3px solid var(--bg);
  border-radius: 50%;
  box-shadow: 0 0 0 2px var(--brand-200);
}

.timeline-content {
  background: var(--bg-card);
  border: 1px solid var(--border);
  border-radius: var(--radius-lg);
  padding: var(--space-5);
  box-shadow: var(--shadow-sm);
  transition: box-shadow var(--transition), transform var(--transition), border-color var(--transition);
}
.timeline-content:hover {
  box-shadow: var(--shadow-md);
  transform: translateY(-2px);
  border-color: var(--brand-200);
}

.timeline-header {
  display: flex;
  flex-wrap: wrap;
  gap: var(--space-3) var(--space-4);
  margin-bottom: var(--space-3);
  align-items: baseline;
}

.timeline-role {
  font-family: var(--font-heading);
  font-size: var(--text-lg);
  font-weight: 600;
  color: var(--fg);
}

.timeline-company {
  font-size: var(--text-base);
  font-weight: 500;
  color: var(--brand-600);
}

.timeline-date {
  font-size: var(--text-sm);
  color: var(--fg-muted);
  white-space: nowrap;
  margin-left: auto;
}

.timeline-desc {
  font-size: var(--text-sm);
  color: var(--fg-muted);
  margin-bottom: var(--space-3);
  line-height: var(--leading-relaxed);
}

.timeline-tasks { display: flex; flex-direction: column; gap: var(--space-2); }
.timeline-task {
  position: relative;
  padding-left: var(--space-5);
  font-size: var(--text-sm);
  color: var(--fg-muted);
  line-height: var(--leading-relaxed);
}
.timeline-task::before {
  content: "";
  position: absolute;
  left: 0;
  top: 0.6em;
  width: 6px;
  height: 6px;
  background: var(--brand-400);
  border-radius: 50%;
  opacity: 0.6;
}

/* Education */
.education-list { display: flex; flex-direction: column; gap: var(--space-4); }
.edu-item {
  display: grid;
  grid-template-columns: auto 1fr;
  gap: var(--space-4);
  padding: var(--space-5);
  background: var(--bg-card);
  border: 1px solid var(--border);
  border-radius: var(--radius-lg);
  box-shadow: var(--shadow-sm);
  transition: box-shadow var(--transition), transform var(--transition), border-color var(--transition);
}
.edu-item:hover {
  box-shadow: var(--shadow-md);
  transform: translateY(-2px);
  border-color: var(--brand-200);
}

.edu-icon {
  width: 48px;
  height: 48px;
  display: flex;
  align-items: center;
  justify-content: center;
  background: var(--brand-100);
  border-radius: var(--radius);
  color: var(--brand-600);
  flex-shrink: 0;
}
.edu-icon .icon { width: 24px; height: 24px; }

.edu-degree { font-family: var(--font-heading); font-size: var(--text-lg); font-weight: 600; color: var(--fg); margin-bottom: var(--space-1); }
.edu-school { font-size: var(--text-base); font-weight: 500; color: var(--brand-600); margin-bottom: var(--space-1); }
.edu-date { font-size: var(--text-sm); color: var(--fg-muted); }

/* Projects Grid */
.projects-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(320px, 1fr));
  gap: var(--space-5);
}

.project-card {
  background: var(--bg-card);
  border: 1px solid var(--border);
  border-radius: var(--radius-xl);
  padding: var(--space-6);
  box-shadow: var(--shadow-sm);
  transition: all var(--transition);
  display: flex;
  flex-direction: column;
}
.project-card:hover {
  box-shadow: var(--shadow-lg);
  transform: translateY(-4px);
  border-color: var(--brand-200);
}

.project-header { margin-bottom: var(--space-3); }
.project-name { font-family: var(--font-heading); font-size: var(--text-xl); font-weight: 700; color: var(--fg); margin-bottom: var(--space-2); }
.project-desc { font-size: var(--text-sm); color: var(--fg-muted); line-height: var(--leading-relaxed); flex: 1; }

.project-tech { display: flex; flex-wrap: wrap; gap: var(--space-2); margin: var(--space-4) 0; }
.tech-tag {
  font-size: var(--text-xs);
  font-weight: 500;
  color: var(--brand-700);
  background: var(--brand-100);
  padding: var(--space-1) var(--space-3);
  border-radius: var(--radius-full);
}

.project-links { display: flex; gap: var(--space-3); margin-top: auto; padding-top: var(--space-4); border-top: 1px solid var(--border); }
.project-link {
  display: inline-flex;
  align-items: center;
  gap: var(--space-2);
  font-size: var(--text-sm);
  font-weight: 500;
  color: var(--brand-600);
  transition: color var(--transition-fast);
}
.project-link:hover { color: var(--brand-700); }
.project-link .icon { width: 16px; height: 16px; }

/* Skills Detail */
.skills-detail-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
  gap: var(--space-5);
}

.skill-category {
  background: var(--bg-card);
  border: 1px solid var(--border);
  border-radius: var(--radius-lg);
  padding: var(--space-5);
  transition: box-shadow var(--transition), border-color var(--transition);
}
.skill-category:hover {
  box-shadow: var(--shadow-md);
  border-color: var(--brand-200);
}

.skill-category-title {
  font-family: var(--font-heading);
  font-size: var(--text-base);
  font-weight: 600;
  color: var(--fg);
  margin-bottom: var(--space-4);
  padding-bottom: var(--space-3);
  border-bottom: 1px solid var(--border);
  display: flex;
  align-items: center;
  gap: var(--space-2);
}
.skill-category-title .icon { width: 20px; height: 20px; color: var(--brand-600); }

.skill-tags { display: flex; flex-wrap: wrap; gap: var(--space-2); }
.skill-tag {
  font-size: var(--text-sm);
  font-weight: 500;
  color: var(--fg);
  background: var(--bg-muted);
  border: 1px solid var(--border);
  padding: var(--space-1) var(--space-3);
  border-radius: var(--radius-full);
  transition: all var(--transition-fast);
}
.skill-tag:hover {
  color: var(--brand-600);
  border-color: var(--brand-300);
  background: var(--brand-50);
}

/* ========================================
   Footer
   ======================================== */
.site-footer {
  background: var(--bg-muted);
  border-top: 1px solid var(--border);
  margin-top: var(--space-16);
}

.footer-content {
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: var(--space-4);
  padding: var(--space-10) var(--container-padding);
  text-align: center;
}

.footer-copyright { font-size: var(--text-sm); color: var(--fg-muted); }
.footer-updated { font-size: var(--text-xs); color: var(--fg-subtle); }

.footer-actions { display: flex; flex-wrap: wrap; gap: var(--space-3); justify-content: center; }

.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: var(--space-2);
  padding: var(--space-3) var(--space-6);
  font-size: var(--text-sm);
  font-weight: 600;
  border-radius: var(--radius);
  transition: all var(--transition-fast);
  white-space: nowrap;
}
.btn .icon { width: 18px; height: 18px; }

.btn-primary {
  background: var(--brand-600);
  color: var(--fg-inverse);
  border: 1px solid var(--brand-600);
}
.btn-primary:hover {
  background: var(--brand-700);
  border-color: var(--brand-700);
  transform: translateY(-1px);
  box-shadow: var(--shadow-md);
}

.btn-outline {
  background: transparent;
  color: var(--fg);
  border: 1px solid var(--border);
}
.btn-outline:hover {
  background: var(--bg-subtle);
  border-color: var(--border-strong);
}

/* ========================================
   Scroll Reveal Animations
   ======================================== */
.reveal {
  opacity: 0;
  transform: translateY(30px);
  transition: opacity 0.6s ease, transform 0.6s ease;
}
.reveal.visible { opacity: 1; transform: none; }

/* Stagger delays */
.reveal:nth-child(1) { transition-delay: 0ms; }
.reveal:nth-child(2) { transition-delay: 100ms; }
.reveal:nth-child(3) { transition-delay: 200ms; }
.reveal:nth-child(4) { transition-delay: 300ms; }
.reveal:nth-child(5) { transition-delay: 400ms; }
.reveal:nth-child(6) { transition-delay: 500ms; }
.reveal:nth-child(7) { transition-delay: 600ms; }
.reveal:nth-child(8) { transition-delay: 700ms; }

/* ========================================
   Print Styles (for PDF)
   ======================================== */
@media print {
  .site-header,
  .site-footer,
  .sidebar,
  .nav-toggle { display: none !important; }

  .main-layout {
    display: block;
    padding: 0;
  }

  .main-content { max-width: none; }

  .section { break-inside: avoid; page-break-inside: avoid; margin-bottom: var(--space-6); }
  .section-title { border-bottom-color: var(--fg-muted); }
  .section-title::after { background: var(--fg); }

  .timeline::before { background: var(--fg-muted); }
  .timeline-marker { background: var(--fg); border-color: var(--bg); box-shadow: 0 0 0 2px var(--fg); }

  .timeline-content,
  .edu-item,
  .project-card,
  .skill-category,
  .objective-card {
    box-shadow: none !important;
    border: 1px solid var(--border) !important;
    break-inside: avoid;
    page-break-inside: avoid;
  }

  .project-links { display: none; }

  a { text-decoration: none; color: var(--fg); }
  a[href^="http"]::after { content: " (" attr(href) ")"; font-size: var(--text-xs); color: var(--fg-muted); }

  body { font-size: 11pt; line-height: 1.6; }
  .profile-name { font-size: 20pt; }
  .section-title { font-size: 14pt; }
}

/* ========================================
   Responsive
   ======================================== */
@media (max-width: 960px) {
  .main-layout {
    grid-template-columns: 1fr;
  }

  .sidebar {
    position: static;
    max-height: none;
    overflow: visible;
    padding-right: 0;
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
    gap: var(--space-4);
  }

  .sidebar-card { margin-bottom: 0; }

  .profile-card { grid-column: 1 / -1; text-align: left; display: flex; gap: var(--space-5); align-items: center; }
  .avatar-wrapper { width: 90px; height: 90px; margin: 0; flex-shrink: 0; }
  .profile-info { text-align: left; }
}

@media (max-width: 768px) {
  :root {
    --header-height: 64px;
    --container-padding: 1rem;
    --space-8: 1.5rem;
    --space-10: 2rem;
  }

  .nav-menu {
    position: fixed;
    top: var(--header-height);
    left: 0;
    right: 0;
    bottom: 0;
    background: var(--bg);
    flex-direction: column;
    padding: var(--space-6);
    gap: var(--space-2);
    border-top: 1px solid var(--border);
    transform: translateY(-100%);
    opacity: 0;
    visibility: hidden;
    transition: all var(--transition);
    box-shadow: var(--shadow-lg);
  }

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

  .nav-link {
    width: 100%;
    padding: var(--space-3) var(--space-4);
    font-size: var(--text-base);
  }

  .nav-toggle { display: flex; }

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

  .profile-card { flex-direction: column; text-align: center; }
  .profile-info { text-align: center; }

  .projects-grid { grid-template-columns: 1fr; }
  .skills-detail-grid { grid-template-columns: 1fr; }

  .edu-item { grid-template-columns: 1fr; text-align: center; }
  .edu-icon { margin: 0 auto; }

  .timeline { padding-left: var(--space-4); }
  .timeline-header { flex-direction: column; align-items: flex-start; gap: var(--space-2); }
  .timeline-date { margin-left: 0; }

  .footer-actions { flex-direction: column; width: 100%; }
  .btn { width: 100%; }
}

@media (max-width: 480px) {
  :root { --container-padding: 0.75rem; }

  .profile-name { font-size: var(--text-xl); }
  .section-title { font-size: var(--text-lg); }

  .timeline-content,
  .edu-item,
  .project-card,
  .skill-category { padding: var(--space-4); }
}

/* ========================================
   Utility Classes
   ======================================== */
.visually-hidden {
  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-muted { color: var(--fg-muted); }
.mt-4 { margin-top: var(--space-4); }
.mb-4 { margin-bottom: var(--space-4); }

/* Keyframes */
@keyframes fadeInUp {
  from { opacity: 0; transform: translateY(20px); }
  to { opacity: 1; transform: none; }
}

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