/* ========================================
   CSS Custom Properties (Design Tokens)
   ======================================== */
:root {
  /* Colors - Modern Professional Palette */
  --color-primary: #2563eb;
  --color-primary-dark: #1d4ed8;
  --color-primary-light: #3b82f6;
  --color-primary-bg: #eff6ff;
  --color-secondary: #0f172a;
  --color-secondary-light: #1e293b;
  --color-accent: #06b6d4;
  --color-accent-bg: #ecfeff;

  /* Neutral Colors */
  --color-white: #ffffff;
  --color-gray-50: #f8fafc;
  --color-gray-100: #f1f5f9;
  --color-gray-200: #e2e8f0;
  --color-gray-300: #cbd5e1;
  --color-gray-400: #94a3b8;
  --color-gray-500: #64748b;
  --color-gray-600: #475569;
  --color-gray-700: #334155;
  --color-gray-800: #1e293b;
  --color-gray-900: #0f172a;

  /* Semantic Colors */
  --color-text-primary: var(--color-gray-900);
  --color-text-secondary: var(--color-gray-600);
  --color-text-muted: var(--color-gray-500);
  --color-text-inverse: var(--color-white);
  --color-border: var(--color-gray-200);
  --color-border-strong: var(--color-gray-300);
  --color-bg: var(--color-white);
  --color-bg-alt: var(--color-gray-50);
  --color-bg-sidebar: var(--color-gray-900);

  /* Sidebar Colors */
  --sidebar-text-primary: var(--color-white);
  --sidebar-text-secondary: rgba(255, 255, 255, 0.8);
  --sidebar-text-muted: rgba(255, 255, 255, 0.6);
  --sidebar-border: rgba(255, 255, 255, 0.1);
  --sidebar-accent: var(--color-accent);

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

  /* Typography */
  --font-family: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, sans-serif;
  --font-family-mono: 'JetBrains Mono', 'Fira Code', monospace;
  --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-weight-light: 300;
  --font-weight-normal: 400;
  --font-weight-medium: 500;
  --font-weight-semibold: 600;
  --font-weight-bold: 700;
  --line-height-tight: 1.1;
  --line-height-normal: 1.5;
  --line-height-relaxed: 1.6;

  /* Border Radius */
  --radius-sm: 0.375rem;
  --radius-md: 0.5rem;
  --radius-lg: 0.75rem;
  --radius-xl: 1rem;
  --radius-full: 9999px;

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

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

  /* Layout */
  --sidebar-width: 280px;
  --container-max-width: 1100px;
  --header-height: auto;
}

/* ========================================
   Reset & Base Styles
   ======================================== */
*,
*::before,
*::after {
  box-sizing: border-box;
  margin: 0;
  padding: 0;
}

html {
  font-size: 16px;
  scroll-behavior: smooth;
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
}

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

/* ========================================
   Layout
   ======================================== */
.cv-container {
  display: grid;
  grid-template-columns: var(--sidebar-width) 1fr;
  min-height: 100vh;
  max-width: var(--container-max-width);
  margin: 0 auto;
  background: var(--color-white);
  box-shadow: var(--shadow-xl);
}

/* ========================================
   Sidebar
   ======================================== */
.sidebar {
  background: var(--color-bg-sidebar);
  color: var(--sidebar-text-primary);
  padding: var(--space-2xl) var(--space-lg);
  display: flex;
  flex-direction: column;
  position: relative;
  overflow-y: auto;
}

.sidebar::before {
  content: '';
  position: absolute;
  top: 0;
  left: 0;
  right: 0;
  height: 4px;
  background: linear-gradient(90deg, var(--color-primary), var(--color-accent));
}

.profile-section {
  text-align: center;
  padding-bottom: var(--space-xl);
  margin-bottom: var(--space-xl);
  border-bottom: 1px solid var(--sidebar-border);
}

.profile-image {
  width: 120px;
  height: 120px;
  margin: 0 auto var(--space-md);
  border-radius: 50%;
  overflow: hidden;
  border: 4px solid var(--sidebar-border);
  box-shadow: var(--shadow-lg);
  transition: transform var(--transition-normal), box-shadow var(--transition-normal);
}

.profile-image:hover {
  transform: scale(1.02);
  box-shadow: var(--shadow-xl);
}

.profile-image img {
  width: 100%;
  height: 100%;
  object-fit: cover;
}

.avatar-placeholder {
  width: 100%;
  height: 100%;
}

.name {
  font-size: var(--font-size-2xl);
  font-weight: var(--font-weight-bold);
  letter-spacing: -0.02em;
  margin-bottom: var(--space-xs);
  color: var(--sidebar-text-primary);
}

.title {
  font-size: var(--font-size-sm);
  font-weight: var(--font-weight-medium);
  color: var(--sidebar-accent);
  text-transform: uppercase;
  letter-spacing: 0.1em;
  margin-bottom: var(--space-lg);
}

.contact-info {
  display: flex;
  flex-direction: column;
  gap: var(--space-sm);
  text-align: left;
  max-width: 220px;
  margin: 0 auto;
}

.contact-item {
  display: flex;
  align-items: center;
  gap: var(--space-sm);
  color: var(--sidebar-text-secondary);
  font-size: var(--font-size-sm);
  text-decoration: none;
  padding: var(--space-xs) var(--space-sm);
  border-radius: var(--radius-md);
  transition: all var(--transition-fast);
}

.contact-item:hover {
  color: var(--sidebar-text-primary);
  background: rgba(255, 255, 255, 0.08);
  transform: translateX(4px);
}

.contact-item .icon {
  width: 18px;
  height: 18px;
  flex-shrink: 0;
  color: var(--sidebar-accent);
}

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

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

.section-title {
  font-size: var(--font-size-xs);
  font-weight: var(--font-weight-semibold);
  text-transform: uppercase;
  letter-spacing: 0.1em;
  color: var(--sidebar-accent);
  margin-bottom: var(--space-md);
  padding-bottom: var(--space-xs);
  border-bottom: 1px solid var(--sidebar-border);
  display: flex;
  align-items: center;
  gap: var(--space-sm);
}

.section-title::before {
  content: '';
  width: 8px;
  height: 8px;
  background: var(--sidebar-accent);
  border-radius: 50%;
}

/* Skills */
.skill-category {
  margin-bottom: var(--space-lg);
}

.skill-category:last-child {
  margin-bottom: 0;
}

.skill-category h3 {
  font-size: var(--font-size-sm);
  font-weight: var(--font-weight-semibold);
  color: var(--sidebar-text-primary);
  margin-bottom: var(--space-sm);
}

.skill-list {
  list-style: none;
  display: flex;
  flex-wrap: wrap;
  gap: var(--space-xs);
}

.skill-list li {
  background: rgba(255, 255, 255, 0.08);
  color: var(--sidebar-text-secondary);
  font-size: var(--font-size-xs);
  font-weight: var(--font-weight-medium);
  padding: var(--space-xs) var(--space-sm);
  border-radius: var(--radius-full);
  border: 1px solid var(--sidebar-border);
  transition: all var(--transition-fast);
}

.skill-list li:hover {
  background: var(--sidebar-accent);
  color: var(--sidebar-text-primary);
  border-color: var(--sidebar-accent);
  transform: translateY(-1px);
}

/* Languages */
.languages {
  display: flex;
  flex-direction: column;
  gap: var(--space-md);
}

.language-item {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: var(--space-md);
}

.lang-name {
  font-size: var(--font-size-sm);
  font-weight: var(--font-weight-medium);
  color: var(--sidebar-text-primary);
  flex: 1;
}

.lang-level {
  display: flex;
  align-items: center;
  gap: var(--space-xs);
  font-size: var(--font-size-xs);
  color: var(--sidebar-text-muted);
}

.lang-dot {
  width: 8px;
  height: 8px;
  border-radius: 50%;
}

.lang-dot.native { background: #22c55e; box-shadow: 0 0 8px #22c55e; }
.lang-dot.fluent { background: var(--color-primary); box-shadow: 0 0 8px var(--color-primary); }
.lang-dot.basic { background: var(--color-accent); box-shadow: 0 0 8px var(--color-accent); }

/* Interests */
.interests {
  list-style: none;
  display: flex;
  flex-direction: column;
  gap: var(--space-sm);
}

.interests li {
  display: flex;
  align-items: center;
  gap: var(--space-sm);
  font-size: var(--font-size-sm);
  color: var(--sidebar-text-secondary);
  padding: var(--space-sm);
  border-radius: var(--radius-md);
  background: rgba(255, 255, 255, 0.04);
  border: 1px solid var(--sidebar-border);
  transition: all var(--transition-fast);
}

.interests li:hover {
  background: rgba(255, 255, 255, 0.1);
  color: var(--sidebar-text-primary);
  border-color: var(--sidebar-accent);
  transform: translateX(4px);
}

.interests .icon {
  width: 20px;
  height: 20px;
  color: var(--sidebar-accent);
  flex-shrink: 0;
}

/* ========================================
   Main Content
   ======================================== */
.main-content {
  padding: var(--space-2xl) var(--space-xl) var(--space-3xl);
  background: var(--color-bg);
}

.section {
  margin-bottom: var(--space-2xl);
}

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

.section-heading {
  font-size: var(--font-size-xl);
  font-weight: var(--font-weight-bold);
  color: var(--color-text-primary);
  margin-bottom: var(--space-lg);
  padding-bottom: var(--space-sm);
  border-bottom: 2px solid var(--color-primary);
  display: inline-block;
  position: relative;
}

.section-heading::after {
  content: '';
  position: absolute;
  bottom: -2px;
  left: 0;
  width: 60px;
  height: 2px;
  background: var(--color-accent);
}

/* Summary */
.summary {
  font-size: var(--font-size-base);
  line-height: var(--line-height-relaxed);
  color: var(--color-text-secondary);
}

.summary strong {
  color: var(--color-text-primary);
  font-weight: var(--font-weight-semibold);
}

/* ========================================
   Experience
   ======================================== */
.experience-item {
  margin-bottom: var(--space-xl);
  padding-left: var(--space-lg);
  border-left: 2px solid var(--color-border);
  position: relative;
}

.experience-item::before {
  content: '';
  position: absolute;
  left: -6px;
  top: 4px;
  width: 10px;
  height: 10px;
  background: var(--color-primary);
  border-radius: 50%;
  border: 3px solid var(--color-white);
  box-shadow: var(--shadow-sm);
}

.experience-item:last-child {
  margin-bottom: 0;
}

.experience-header {
  display: flex;
  justify-content: space-between;
  align-items: flex-start;
  gap: var(--space-md);
  margin-bottom: var(--space-md);
  flex-wrap: wrap;
}

.job-title {
  font-size: var(--font-size-lg);
  font-weight: var(--font-weight-semibold);
  color: var(--color-text-primary);
  margin-bottom: var(--space-xs);
}

.company {
  font-size: var(--font-size-base);
  color: var(--color-primary);
  font-weight: var(--font-weight-medium);
}

.date-badge {
  background: var(--color-primary-bg);
  color: var(--color-primary);
  font-size: var(--font-size-xs);
  font-weight: var(--font-weight-semibold);
  padding: var(--space-xs) var(--space-md);
  border-radius: var(--radius-full);
  white-space: nowrap;
  flex-shrink: 0;
}

.achievements {
  list-style: none;
  margin-bottom: var(--space-md);
}

.achievements li {
  position: relative;
  padding-left: var(--space-lg);
  margin-bottom: var(--space-sm);
  font-size: var(--font-size-sm);
  line-height: var(--line-height-relaxed);
  color: var(--color-text-secondary);
}

.achievements li::before {
  content: '▹';
  position: absolute;
  left: 0;
  color: var(--color-primary);
  font-weight: bold;
}

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

.tech-stack {
  display: flex;
  flex-wrap: wrap;
  gap: var(--space-xs);
}

.tech-tag {
  background: var(--color-gray-100);
  color: var(--color-gray-700);
  font-size: var(--font-size-xs);
  font-weight: var(--font-weight-medium);
  padding: var(--space-xs) var(--space-sm);
  border-radius: var(--radius-sm);
  transition: all var(--transition-fast);
  border: 1px solid transparent;
}

.tech-tag:hover {
  background: var(--color-primary);
  color: var(--color-white);
  border-color: var(--color-primary);
  transform: translateY(-1px);
  box-shadow: var(--shadow-md);
}

/* ========================================
   Projects
   ======================================== */
.projects-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(300px, 1fr));
  gap: var(--space-lg);
}

.project-card {
  background: var(--color-white);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-lg);
  padding: var(--space-lg);
  transition: all var(--transition-normal);
  position: relative;
  overflow: hidden;
}

.project-card::before {
  content: '';
  position: absolute;
  top: 0;
  left: 0;
  right: 0;
  height: 3px;
  background: linear-gradient(90deg, var(--color-primary), var(--color-accent));
  transform: scaleX(0);
  transform-origin: left;
  transition: transform var(--transition-normal);
}

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

.project-card:hover::before {
  transform: scaleX(1);
}

.project-header {
  display: flex;
  justify-content: space-between;
  align-items: flex-start;
  margin-bottom: var(--space-md);
}

.project-name {
  font-size: var(--font-size-lg);
  font-weight: var(--font-weight-semibold);
  color: var(--color-text-primary);
}

.project-link {
  display: flex;
  align-items: center;
  justify-content: center;
  width: 36px;
  height: 36px;
  background: var(--color-gray-100);
  border-radius: var(--radius-md);
  color: var(--color-gray-500);
  text-decoration: none;
  transition: all var(--transition-fast);
  flex-shrink: 0;
}

.project-link:hover {
  background: var(--color-primary);
  color: var(--color-white);
  transform: rotate(45deg);
}

.project-link svg {
  width: 18px;
  height: 18px;
  transition: transform var(--transition-fast);
}

.project-link:hover svg {
  transform: rotate(-45deg);
}

.project-description {
  font-size: var(--font-size-sm);
  line-height: var(--line-height-relaxed);
  color: var(--color-text-secondary);
  margin-bottom: var(--space-md);
}

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

.project-tech .tech-tag {
  background: var(--color-primary-bg);
  color: var(--color-primary);
  border-color: var(--color-primary);
}

.project-tech .tech-tag:hover {
  background: var(--color-primary);
  color: var(--color-white);
}

/* ========================================
   Education
   ======================================== */
.education-list {
  display: flex;
  flex-direction: column;
  gap: var(--space-lg);
}

.education-item {
  display: flex;
  gap: var(--space-md);
  padding: var(--space-lg);
  background: var(--color-white);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-lg);
  transition: all var(--transition-normal);
}

.education-item:hover {
  border-color: var(--color-primary);
  box-shadow: var(--shadow-md);
  transform: translateX(4px);
}

.education-icon {
  width: 48px;
  height: 48px;
  display: flex;
  align-items: center;
  justify-content: center;
  background: var(--color-primary-bg);
  border-radius: var(--radius-md);
  color: var(--color-primary);
  flex-shrink: 0;
}

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

.education-content {
  flex: 1;
}

.degree {
  font-size: var(--font-size-base);
  font-weight: var(--font-weight-semibold);
  color: var(--color-text-primary);
  margin-bottom: var(--space-xs);
}

.school {
  font-size: var(--font-size-sm);
  font-weight: var(--font-weight-medium);
  color: var(--color-primary);
  margin-bottom: var(--space-xs);
}

.education-meta {
  font-size: var(--font-size-sm);
  color: var(--color-text-muted);
  margin-bottom: var(--space-xs);
}

.education-detail {
  font-size: var(--font-size-sm);
  color: var(--color-text-secondary);
  line-height: var(--line-height-relaxed);
}

/* ========================================
   Certifications
   ======================================== */
.certifications {
  display: flex;
  flex-direction: column;
  gap: var(--space-md);
}

.cert-item {
  display: flex;
  align-items: flex-start;
  gap: var(--space-md);
  padding: var(--space-md) var(--space-lg);
  background: var(--color-white);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-lg);
  transition: all var(--transition-normal);
}

.cert-item:hover {
  border-color: var(--color-accent);
  box-shadow: var(--shadow-md);
  transform: translateX(4px);
}

.cert-icon {
  font-size: var(--font-size-xl);
  flex-shrink: 0;
}

.cert-item div {
  flex: 1;
}

.cert-item strong {
  font-size: var(--font-size-base);
  font-weight: var(--font-weight-semibold);
  color: var(--color-text-primary);
  display: block;
  margin-bottom: var(--space-xs);
}

.cert-item small {
  font-size: var(--font-size-sm);
  color: var(--color-text-muted);
}

/* ========================================
   Footer
   ======================================== */
.footer {
  grid-column: 1 / -1;
  background: var(--color-gray-900);
  color: var(--color-gray-400);
  text-align: center;
  padding: var(--space-md);
  font-size: var(--font-size-sm);
}

.footer p {
  margin: 0;
}

/* ========================================
   Print Styles
   ======================================== */
@media print {
  .cv-container {
    box-shadow: none;
    max-width: none;
  }

  .sidebar {
    background: var(--color-gray-900) !important;
    -webkit-print-color-adjust: exact;
    print-color-adjust: exact;
  }

  .main-content {
    padding: var(--space-lg);
  }

  .section {
    break-inside: avoid;
    page-break-inside: avoid;
  }

  .experience-item,
  .education-item,
  .project-card,
  .cert-item {
    break-inside: avoid;
    page-break-inside: avoid;
  }

  .footer {
    display: none;
  }

  .project-link,
  .contact-item {
    text-decoration: none;
  }

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

/* ========================================
   Responsive
   ======================================== */
@media (max-width: 900px) {
  .cv-container {
    grid-template-columns: 1fr;
  }

  .sidebar {
    padding: var(--space-xl) var(--space-lg);
  }

  .contact-info {
    max-width: none;
    flex-direction: row;
    flex-wrap: wrap;
    justify-content: center;
    gap: var(--space-md);
  }

  .contact-item {
    padding: var(--space-sm) var(--space-md);
  }

  .main-content {
    padding: var(--space-xl) var(--space-lg) var(--space-2xl);
  }

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

@media (max-width: 600px) {
  :root {
    --font-size-2xl: 1.25rem;
    --font-size-xl: 1.125rem;
    --font-size-lg: 1rem;
  }

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

  .date-badge {
    align-self: flex-start;
  }

  .education-item {
    flex-direction: column;
    text-align: center;
  }

  .education-icon {
    margin: 0 auto;
  }

  .cert-item {
    flex-direction: column;
    text-align: center;
  }

  .cert-icon {
    margin: 0 auto var(--space-sm);
  }
}

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

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

.section {
  animation: fadeInUp 0.6s ease forwards;
  opacity: 0;
}

.section:nth-child(1) { animation-delay: 0.1s; }
.section:nth-child(2) { animation-delay: 0.2s; }
.section:nth-child(3) { animation-delay: 0.3s; }
.section:nth-child(4) { animation-delay: 0.4s; }
.section:nth-child(5) { animation-delay: 0.5s; }
.section:nth-child(6) { animation-delay: 0.6s; }

.sidebar-section {
  animation: fadeInUp 0.5s ease forwards;
  opacity: 0;
}

.sidebar-section:nth-child(1) { animation-delay: 0.1s; }
.sidebar-section:nth-child(2) { animation-delay: 0.2s; }
.sidebar-section:nth-child(3) { animation-delay: 0.3s; }
.sidebar-section:nth-child(4) { animation-delay: 0.4s; }

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

@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;
  }
}

/* ========================================
   Focus Styles (Accessibility)
   ======================================== */
*:focus-visible {
  outline: 2px solid var(--color-primary);
  outline-offset: 2px;
}

.contact-item:focus-visible,
.project-link:focus-visible,
.tech-tag:focus-visible {
  outline: 2px solid var(--color-accent);
  outline-offset: 2px;
}