/* ===================================
   CSS Custom Properties (Design Tokens)
   =================================== */
:root {
  /* Colors - Light Theme */
  --color-bg: #fafafa;
  --color-bg-elevated: #ffffff;
  --color-bg-sidebar: #1a1a2e;
  --color-text-primary: #1a1a2e;
  --color-text-secondary: #4a4a6a;
  --color-text-muted: #6b6b8a;
  --color-text-on-dark: #f0f0f5;
  --color-text-on-dark-muted: #a0a0c0;
  --color-accent: #2563eb;
  --color-accent-hover: #1d4ed8;
  --color-accent-light: #dbeafe;
  --color-border: #e0e0ea;
  --color-border-dark: #2d2d4a;
  --color-focus: #2563eb;
  --color-shadow: rgba(26, 26, 46, 0.08);
  --color-shadow-strong: rgba(26, 26, 46, 0.15);

  /* Typography */
  --font-family: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, 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-weight-light: 300;
  --font-weight-normal: 400;
  --font-weight-medium: 500;
  --font-weight-semibold: 600;
  --font-weight-bold: 700;
  --line-height-tight: 1.2;
  --line-height-normal: 1.5;
  --line-height-relaxed: 1.75;

  /* 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;

  /* Layout */
  --sidebar-width: 280px;
  --header-height: auto;
  --border-radius: 8px;
  --border-radius-lg: 12px;
  --border-radius-full: 9999px;

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

  /* Z-index */
  --z-sticky: 10;
  --z-modal: 100;
}

/* Dark theme (optional - can be toggled) */
@media (prefers-color-scheme: dark) {
  :root {
    --color-bg: #0f0f1a;
    --color-bg-elevated: #1a1a2e;
    --color-bg-sidebar: #0a0a15;
    --color-text-primary: #f0f0f5;
    --color-text-secondary: #c0c0d0;
    --color-text-muted: #8080a0;
    --color-border: #2d2d4a;
    --color-shadow: rgba(0, 0, 0, 0.3);
    --color-shadow-strong: rgba(0, 0, 0, 0.5);
    --color-accent-light: #1e3a5f;
  }
}

/* ===================================
   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;
}

/* Focus styles for accessibility */
:focus-visible {
  outline: 2px solid var(--color-focus);
  outline-offset: 2px;
}

/* Selection */
::selection {
  background-color: var(--color-accent-light);
  color: var(--color-accent);
}

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

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

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

/* ===================================
   Layout
   =================================== */
.cv-container {
  display: grid;
  grid-template-columns: var(--sidebar-width) 1fr;
  min-height: 100vh;
  max-width: 1200px;
  margin: 0 auto;
  background-color: var(--color-bg-elevated);
  box-shadow: 0 0 0 1px var(--color-border), 0 4px 24px var(--color-shadow);
}

/* ===================================
   Sidebar
   =================================== */
.sidebar {
  background-color: var(--color-bg-sidebar);
  color: var(--color-text-on-dark);
  padding: var(--space-8) var(--space-6);
  display: flex;
  flex-direction: column;
  gap: var(--space-8);
  position: sticky;
  top: 0;
  height: 100vh;
  overflow-y: auto;
  border-right: 1px solid var(--color-border-dark);
}

.sidebar a {
  color: var(--color-text-on-dark-muted);
}

.sidebar a:hover {
  color: var(--color-text-on-dark);
}

/* Profile Section */
.profile-section {
  text-align: center;
  padding-bottom: var(--space-6);
  border-bottom: 1px solid var(--color-border-dark);
}

.avatar-wrapper {
  width: 100px;
  height: 100px;
  margin: 0 auto var(--space-4);
  border-radius: 50%;
  overflow: hidden;
  background: linear-gradient(135deg, var(--color-accent), #7c3aed);
  box-shadow: 0 4px 16px rgba(37, 99, 235, 0.3);
}

.avatar-placeholder {
  width: 100%;
  height: 100%;
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: var(--font-size-2xl);
  font-weight: var(--font-weight-bold);
  color: var(--color-text-on-dark);
}

.name {
  font-size: var(--font-size-2xl);
  font-weight: var(--font-weight-bold);
  line-height: var(--line-height-tight);
  margin-bottom: var(--space-1);
  color: var(--color-text-on-dark);
}

.title {
  font-size: var(--font-size-base);
  font-weight: var(--font-weight-medium);
  color: var(--color-accent);
  margin-bottom: var(--space-4);
}

.location {
  display: inline-flex;
  align-items: center;
  gap: var(--space-2);
  font-size: var(--font-size-sm);
  color: var(--color-text-on-dark-muted);
}

.location .icon {
  width: 16px;
  height: 16px;
  flex-shrink: 0;
}

/* Contact Info */
.contact-info {
  display: flex;
  flex-direction: column;
  gap: var(--space-3);
}

.contact-item {
  display: flex;
  align-items: center;
  gap: var(--space-3);
  padding: var(--space-2) var(--space-3);
  border-radius: var(--border-radius);
  transition: background-color var(--transition-fast);
  font-size: var(--font-size-sm);
  word-break: break-all;
}

.contact-item:hover {
  background-color: var(--color-border-dark);
  color: var(--color-text-on-dark);
}

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

/* Section Title (Sidebar) */
.section-title {
  font-size: var(--font-size-xs);
  font-weight: var(--font-weight-semibold);
  text-transform: uppercase;
  letter-spacing: 0.1em;
  color: var(--color-accent);
  margin-bottom: var(--space-4);
}

/* Skills Section */
.skills-section {
  display: flex;
  flex-direction: column;
  gap: var(--space-5);
}

.skills-category h3.category-title {
  font-size: var(--font-size-sm);
  font-weight: var(--font-weight-semibold);
  color: var(--color-text-on-dark);
  margin-bottom: var(--space-3);
}

.skills-list {
  list-style: none;
  display: flex;
  flex-direction: column;
  gap: var(--space-2);
}

.skills-list li {
  font-size: var(--font-size-sm);
  color: var(--color-text-on-dark-muted);
  line-height: var(--line-height-relaxed);
  padding-left: var(--space-4);
  position: relative;
}

.skills-list li::before {
  content: '';
  position: absolute;
  left: 0;
  top: 0.6em;
  width: 6px;
  height: 6px;
  border-radius: 50%;
  background-color: var(--color-accent);
  opacity: 0.6;
}

/* Languages Section */
.languages-list {
  list-style: none;
  display: flex;
  flex-direction: column;
  gap: var(--space-3);
}

.languages-list li {
  display: flex;
  justify-content: space-between;
  align-items: center;
  padding: var(--space-2) var(--space-3);
  background-color: rgba(255, 255, 255, 0.03);
  border-radius: var(--border-radius);
  transition: background-color var(--transition-fast);
}

.languages-list li:hover {
  background-color: rgba(255, 255, 255, 0.06);
}

.lang-name {
  font-weight: var(--font-weight-medium);
  font-size: var(--font-size-sm);
}

.lang-level {
  font-size: var(--font-size-xs);
  color: var(--color-text-on-dark-muted);
}

/* ===================================
   Main Content
   =================================== */
.main-content {
  padding: var(--space-10) var(--space-12);
  overflow-y: auto;
}

.section {
  margin-bottom: var(--space-12);
}

.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-6);
  padding-bottom: var(--space-3);
  border-bottom: 2px solid var(--color-accent);
  display: inline-block;
}

/* Summary / About */
.summary {
  font-size: var(--font-size-base);
  line-height: var(--line-height-relaxed);
  color: var(--color-text-secondary);
  max-width: 800px;
}

/* ===================================
   Experience
   =================================== */
.experience-item {
  margin-bottom: var(--space-8);
  padding-bottom: var(--space-8);
  border-bottom: 1px solid var(--color-border);
}

.experience-item:last-child {
  margin-bottom: 0;
  padding-bottom: 0;
  border-bottom: none;
}

.experience-header {
  display: flex;
  justify-content: space-between;
  align-items: flex-start;
  gap: var(--space-4);
  margin-bottom: var(--space-4);
  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-1);
}

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

.date-range {
  font-size: var(--font-size-sm);
  color: var(--color-text-muted);
  white-space: nowrap;
  background-color: var(--color-accent-light);
  padding: var(--space-1) var(--space-3);
  border-radius: var(--border-radius-full);
  font-weight: var(--font-weight-medium);
}

.achievements {
  list-style: none;
  display: flex;
  flex-direction: column;
  gap: var(--space-2);
  margin-bottom: var(--space-4);
}

.achievements li {
  font-size: var(--font-size-sm);
  line-height: var(--line-height-relaxed);
  color: var(--color-text-secondary);
  padding-left: var(--space-5);
  position: relative;
}

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

.tech-stack {
  display: flex;
  flex-wrap: wrap;
  gap: var(--space-2);
}

.tech-stack span {
  font-size: var(--font-size-xs);
  font-weight: var(--font-weight-medium);
  color: var(--color-text-secondary);
  background-color: var(--color-accent-light);
  padding: var(--space-1) var(--space-2);
  border-radius: var(--border-radius-full);
  white-space: nowrap;
}

/* ===================================
   Projects
   =================================== */
.projects-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(320px, 1fr));
  gap: var(--space-6);
}

.project-card {
  background-color: var(--color-bg);
  border: 1px solid var(--color-border);
  border-radius: var(--border-radius-lg);
  padding: var(--space-6);
  transition: transform var(--transition-normal), box-shadow var(--transition-normal), border-color var(--transition-normal);
}

.project-card:hover {
  transform: translateY(-4px);
  box-shadow: 0 12px 32px var(--color-shadow-strong);
  border-color: var(--color-accent);
}

.project-content {
  display: flex;
  flex-direction: column;
  height: 100%;
}

.project-title {
  font-size: var(--font-size-lg);
  font-weight: var(--font-weight-semibold);
  color: var(--color-text-primary);
  margin-bottom: var(--space-2);
}

.project-desc {
  font-size: var(--font-size-sm);
  line-height: var(--line-height-relaxed);
  color: var(--color-text-secondary);
  margin-bottom: var(--space-4);
  flex-grow: 1;
}

.project-tech {
  display: flex;
  flex-wrap: wrap;
  gap: var(--space-2);
  margin-bottom: var(--space-4);
}

.project-tech span {
  font-size: var(--font-size-xs);
  font-weight: var(--font-weight-medium);
  color: var(--color-accent);
  background-color: var(--color-accent-light);
  padding: var(--space-1) var(--space-2);
  border-radius: var(--border-radius-full);
}

.project-links {
  display: flex;
  gap: var(--space-4);
}

.project-links a {
  font-size: var(--font-size-sm);
  font-weight: var(--font-weight-medium);
  color: var(--color-accent);
  padding: var(--space-1) 0;
  border-bottom: 1px solid transparent;
  transition: border-color var(--transition-fast);
}

.project-links a:hover {
  border-bottom-color: var(--color-accent);
}

/* ===================================
   Education
   =================================== */
.education-item {
  margin-bottom: var(--space-6);
  padding-bottom: var(--space-6);
  border-bottom: 1px solid var(--color-border);
}

.education-item:last-child {
  margin-bottom: 0;
  padding-bottom: 0;
  border-bottom: none;
}

.education-header {
  display: flex;
  justify-content: space-between;
  align-items: flex-start;
  gap: var(--space-4);
  margin-bottom: var(--space-2);
  flex-wrap: wrap;
}

.degree {
  font-size: var(--font-size-lg);
  font-weight: var(--font-weight-semibold);
  color: var(--color-text-primary);
  margin-bottom: var(--space-1);
}

.school {
  font-size: var(--font-size-base);
  color: var(--color-accent);
  font-weight: var(--font-weight-medium);
}

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

/* ===================================
   Awards & Certifications
   =================================== */
.awards-list {
  list-style: none;
  display: flex;
  flex-direction: column;
  gap: var(--space-3);
}

.awards-list li {
  font-size: var(--font-size-sm);
  line-height: var(--line-height-relaxed);
  color: var(--color-text-secondary);
  padding-left: var(--space-5);
  position: relative;
}

.awards-list li::before {
  content: '★';
  position: absolute;
  left: 0;
  color: var(--color-accent);
  font-size: var(--font-size-xs);
}

/* ===================================
   Footer
   =================================== */
.footer {
  grid-column: 1 / -1;
  text-align: center;
  padding: var(--space-6);
  color: var(--color-text-muted);
  font-size: var(--font-size-sm);
  border-top: 1px solid var(--color-border);
  background-color: var(--color-bg-elevated);
}

/* ===================================
   Icons
   =================================== */
.icon {
  display: inline-block;
  vertical-align: middle;
}

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

  .sidebar {
    position: static;
    height: auto;
    page-break-after: always;
    border-right: none;
    padding: var(--space-6);
  }

  .main-content {
    padding: var(--space-6);
  }

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

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

  a {
    color: var(--color-text-primary);
    text-decoration: none;
  }

  .contact-item .icon,
  .project-links a {
    color: var(--color-text-primary);
  }

  .tech-stack span,
  .project-tech span {
    background-color: transparent;
    border: 1px solid var(--color-border);
    color: var(--color-text-secondary);
  }

  .date-range {
    background-color: transparent;
    border: 1px solid var(--color-border);
  }

  .footer {
    display: none;
  }

  body {
    background: white;
  }
}

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

  .sidebar {
    position: static;
    height: auto;
    min-height: auto;
    border-right: none;
    border-bottom: 1px solid var(--color-border-dark);
    padding: var(--space-6);
  }

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

  .avatar-wrapper {
    margin: 0 0 var(--space-4);
  }

  .contact-info {
    flex-direction: row;
    flex-wrap: wrap;
    gap: var(--space-2);
  }

  .contact-item {
    padding: var(--space-2) var(--space-3);
    white-space: nowrap;
  }

  .skills-section {
    flex-direction: row;
    flex-wrap: wrap;
  }

  .skills-category {
    flex: 1;
    min-width: 200px;
  }

  .main-content {
    padding: var(--space-6) var(--space-8);
  }
}

@media (max-width: 600px) {
  :root {
    --space-6: 1rem;
    --space-8: 1.5rem;
    --space-10: 1.5rem;
    --space-12: 2rem;
  }

  html {
    font-size: 14px;
  }

  .sidebar {
    padding: var(--space-4);
  }

  .main-content {
    padding: var(--space-4) var(--space-5);
  }

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

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

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

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

/* ===================================
   Reduced Motion
   =================================== */
@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;
  }
}

/* ===================================
   High Contrast Mode Support
   =================================== */
@media (prefers-contrast: high) {
  :root {
    --color-border: #000;
    --color-border-dark: #fff;
    --color-accent: #0000ee;
    --color-accent-hover: #0000cc;
  }

  .contact-item:hover,
  .languages-list li:hover,
  .project-card:hover {
    background-color: transparent;
    border: 2px solid currentColor;
  }

  .tech-stack span,
  .project-tech span {
    border: 1px solid currentColor;
    background: transparent;
  }
}