/* ===== CSS VARIABLES & RESET ===== */
:root {
  /* Professional color palette with contrast */
  --color-primary: #0f172a;
  --color-primary-dark: #020617;
  --color-secondary: #334155;
  --color-accent: #3b82f6;
  --color-accent-hover: #2563eb;
  --color-success: #10b981;
  --color-success-hover: #059669;
  --color-warning: #f59e0b;
  
  --color-text: #1e293b;
  --color-text-light: #475569;
  --color-text-muted: #64748b;
  
  --color-bg: #ffffff;
  --color-bg-alt: #f8fafc;
  --color-bg-section: #f1f5f9;
  --color-bg-code: #f1f5f9;
  
  --color-border: #e2e8f0;
  --color-border-light: #f1f5f9;
  
  /* Typography */
  --font-family: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, sans-serif;
  --font-size-base: 16px;
  --font-size-sm: 0.875rem;
  --font-size-md: 1rem;
  --font-size-lg: 1.25rem;
  --font-size-xl: 1.5rem;
  --font-size-2xl: 2rem;
  --font-size-3xl: 2.5rem;
  --line-height: 1.6;
  --line-height-tight: 1.4;
  
  /* Spacing */
  --spacing-xs: 0.25rem;
  --spacing-sm: 0.5rem;
  --spacing-md: 1rem;
  --spacing-lg: 1.5rem;
  --spacing-xl: 2rem;
  --spacing-2xl: 3rem;
  --spacing-3xl: 4rem;
  
  /* Layout */
  --max-width: 1100px;
  --border-radius: 6px;
  --border-radius-lg: 12px;
  --shadow-sm: 0 1px 2px rgba(0, 0, 0, 0.05);
  --shadow-md: 0 4px 6px rgba(0, 0, 0, 0.07);
  --shadow-lg: 0 10px 25px rgba(0, 0, 0, 0.1);
  --shadow-xl: 0 20px 40px rgba(0, 0, 0, 0.12);
  
  /* Transitions & Animation */
  --transition-fast: 150ms ease;
  --transition-normal: 250ms ease;
  --transition-slow: 400ms ease;
}

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

html { font-size: var(--font-size-base); scroll-behavior: smooth; }

body {
  font-family: var(--font-family);
  font-size: var(--font-size-md);
  line-height: var(--line-height);
  color: var(--color-text);
  background-color: var(--color-bg);
  -webkit-font-smoothing: antialiased;
}

/* ===== TYPOGRAPHY ===== */
h1, h2, h3, h4 {
  font-weight: 600;
  line-height: var(--line-height-tight);
  color: var(--color-primary);
  margin-bottom: var(--spacing-md);
}

h1 { font-size: var(--font-size-3xl); font-weight: 700; letter-spacing: -0.02em; }

h2 {
  font-size: var(--font-size-2xl);
  padding-bottom: var(--spacing-sm);
  border-bottom: 2px solid var(--color-border);
  margin-bottom: var(--spacing-lg);
  position: relative;
}

h2::after {
  content: '';
  position: absolute;
  bottom: -2px;
  left: 0;
  width: 60px;
  height: 2px;
  background: var(--color-accent);
}

h3 { font-size: var(--font-size-lg); font-weight: 600; }
h4 { font-size: var(--font-size-md); font-weight: 600; color: var(--color-text); margin-bottom: var(--spacing-sm); }

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

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

ul, ol { margin-left: var(--spacing-lg); margin-bottom: var(--spacing-md); }
li { margin-bottom: var(--spacing-xs); color: var(--color-text-light); }

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

.section {
  padding: var(--spacing-2xl) 0;
  border-bottom: 1px solid var(--color-border-light);
  opacity: 0;
  transform: translateY(20px);
  transition: opacity var(--transition-slow), transform var(--transition-slow);
}

.section.visible { opacity: 1; transform: translateY(0); }

.section:last-child { border-bottom: none; }

/* Alternating section backgrounds for contrast */
.section-alt {
  background-color: var(--color-bg-section);
}

.grid-2 { display: grid; grid-template-columns: repeat(auto-fit, minmax(320px, 1fr)); gap: var(--spacing-lg); }
.grid-3 { display: grid; grid-template-columns: repeat(auto-fit, minmax(280px, 1fr)); gap: var(--spacing-lg); }

/* ===== HEADER & NAVIGATION ===== */
.site-header {
  position: sticky;
  top: 0;
  z-index: 100;
  background-color: rgba(255, 255, 255, 0.95);
  backdrop-filter: blur(10px);
  border-bottom: 1px solid var(--color-border);
  padding: var(--spacing-md) 0;
  transition: box-shadow var(--transition-fast);
}

.site-header.scrolled { box-shadow: var(--shadow-md); }

.header-content { display: flex; justify-content: space-between; align-items: center; }

.logo a {
  font-size: var(--font-size-lg);
  font-weight: 700;
  color: var(--color-primary);
  letter-spacing: -0.01em;
}

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

.nav-links a {
  font-size: var(--font-size-sm);
  font-weight: 500;
  color: var(--color-text);
  position: relative;
  padding: var(--spacing-xs) 0;
}

.nav-links a::after {
  content: '';
  position: absolute;
  bottom: 0;
  left: 0;
  width: 0;
  height: 2px;
  background: var(--color-accent);
  transition: width var(--transition-fast);
}

.nav-links a:hover::after { width: 100%; }

/* ===== HERO SECTION ===== */
.hero {
  background: linear-gradient(135deg, var(--color-primary) 0%, var(--color-primary-dark) 100%);
  color: var(--color-bg);
  padding: var(--spacing-3xl) 0;
  position: relative;
  overflow: hidden;
}

.hero-content {
  display: flex;
  align-items: center;
  gap: var(--spacing-2xl);
  position: relative;
  z-index: 2;
}

.hero-text { flex: 1; }
.hero-image { flex: 0 0 220px; text-align: center; }

.hero-badge {
  display: inline-block;
  background: rgba(255, 255, 255, 0.15);
  color: var(--color-bg);
  padding: var(--spacing-xs) var(--spacing-md);
  border-radius: 20px;
  font-size: var(--font-size-sm);
  font-weight: 500;
  margin-bottom: var(--spacing-md);
  border: 1px solid rgba(255, 255, 255, 0.2);
}

.hero h1 { color: var(--color-bg); margin-bottom: var(--spacing-sm); font-size: var(--font-size-3xl); }

.hero-title {
  font-size: var(--font-size-xl);
  font-weight: 500;
  margin-bottom: var(--spacing-md);
  color: rgba(255, 255, 255, 0.95);
}

.hero-subtitle {
  font-size: var(--font-size-md);
  margin-bottom: var(--spacing-lg);
  color: rgba(255, 255, 255, 0.9);
  max-width: 600px;
}

.hero-cta { display: flex; gap: var(--spacing-md); flex-wrap: wrap; }

.profile-photo {
  width: 200px;
  height: 200px;
  border-radius: 50%;
  object-fit: cover;
  border: 4px solid rgba(255, 255, 255, 0.3);
  box-shadow: var(--shadow-xl);
  transition: transform var(--transition-normal);
}

.profile-photo:hover { transform: scale(1.03); }

.hero-wave {
  position: absolute;
  bottom: 0;
  left: 0;
  right: 0;
  height: 60px;
  background: url("data:image/svg+xml,%3Csvg viewBox='0 0 1440 60' fill='none' xmlns='http://www.w3.org/2000/svg'%3E%3Cpath d='M0 60L1440 0V60H0Z' fill='%23f8fafc'/%3E%3C/svg%3E");
  background-size: cover;
}

/* ===== BUTTONS ===== */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  padding: var(--spacing-sm) var(--spacing-lg);
  border-radius: var(--border-radius);
  font-weight: 600;
  font-size: var(--font-size-sm);
  text-align: center;
  cursor: pointer;
  transition: all var(--transition-fast);
  border: 1px solid transparent;
  gap: var(--spacing-xs);
}

.btn-primary { background-color: var(--color-accent); color: var(--color-bg); }
.btn-primary:hover { background-color: var(--color-accent-hover); transform: translateY(-1px); box-shadow: var(--shadow-md); }

.btn-secondary { background-color: var(--color-success); color: var(--color-bg); }
.btn-secondary:hover { background-color: var(--color-success-hover); transform: translateY(-1px); box-shadow: var(--shadow-md); }

.btn-outline { background-color: transparent; border-color: var(--color-bg); color: var(--color-bg); }
.btn-outline:hover { background-color: rgba(255, 255, 255, 0.1); transform: translateY(-1px); }

.btn-sm { padding: var(--spacing-xs) var(--spacing-md); font-size: var(--font-size-sm); }

/* ===== EXPERIENCE CARDS ===== */
.experience-card {
  background-color: var(--color-bg);
  padding: var(--spacing-lg);
  border-radius: var(--border-radius-lg);
  margin-bottom: var(--spacing-lg);
  border-left: 4px solid var(--color-accent);
  box-shadow: var(--shadow-sm);
  transition: transform var(--transition-fast), box-shadow var(--transition-fast);
}

.experience-card:hover {
  transform: translateY(-2px);
  box-shadow: var(--shadow-md);
}

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

.experience-header h3 { margin: 0; }

.company {
  font-size: var(--font-size-md);
  color: var(--color-text);
  font-weight: 500;
  margin: 0;
}

.experience-date {
  font-size: var(--font-size-sm);
  color: var(--color-text-muted);
  white-space: nowrap;
}

.experience-list { padding-left: var(--spacing-lg); margin: var(--spacing-md) 0; }
.experience-list li { margin-bottom: var(--spacing-md); line-height: var(--line-height); }
.experience-list strong { color: var(--color-text); font-weight: 600; }

/* ===== PROJECT CARDS ===== */
.project-card {
  background-color: var(--color-bg);
  padding: var(--spacing-lg);
  border-radius: var(--border-radius-lg);
  margin-bottom: var(--spacing-lg);
  box-shadow: var(--shadow-sm);
  transition: transform var(--transition-fast), box-shadow var(--transition-fast);
}

.project-card:hover {
  transform: translateY(-3px);
  box-shadow: var(--shadow-lg);
}

.project-card.featured {
  border: 1px solid var(--color-border);
  background: linear-gradient(to bottom right, var(--color-bg), var(--color-bg-alt));
}

.project-card.with-media {
  background-color: var(--color-bg-alt);
}

.project-header {
  display: flex;
  align-items: center;
  gap: var(--spacing-sm);
  margin-bottom: var(--spacing-sm);
  flex-wrap: wrap;
}

.badge {
  background-color: var(--color-primary);
  color: var(--color-bg);
  padding: var(--spacing-xs) var(--spacing-sm);
  border-radius: 20px;
  font-size: var(--font-size-sm);
  font-weight: 500;
}

.badge-success {
  background-color: var(--color-success);
  color: var(--color-bg);
  padding: var(--spacing-xs) var(--spacing-sm);
  border-radius: 20px;
  font-size: var(--font-size-sm);
  font-weight: 500;
}

.badge-secondary {
  background-color: var(--color-secondary);
  color: var(--color-bg);
  padding: var(--spacing-xs) var(--spacing-sm);
  border-radius: 20px;
  font-size: var(--font-size-sm);
  font-weight: 500;
}

.project-meta {
  font-size: var(--font-size-sm);
  color: var(--color-text-muted);
  margin-bottom: var(--spacing-md);
  font-style: italic;
}

.results-list { margin: var(--spacing-md) 0; padding-left: var(--spacing-lg); }
.results-list li { margin-bottom: var(--spacing-sm); }

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

.video-container {
  margin-top: var(--spacing-md);
  display: none;
  border-radius: var(--border-radius);
  overflow: hidden;
  box-shadow: var(--shadow-md);
}

/* Media Preview for GIFs */
.media-preview {
  margin: var(--spacing-md) 0;
  border-radius: var(--border-radius);
  overflow: hidden;
  background: var(--color-bg-code);
}

.project-gif {
  width: 100%;
  max-height: 300px;
  object-fit: contain;
  display: block;
  background: var(--color-bg-code);
}

.media-caption {
  display: block;
  padding: var(--spacing-sm);
  font-size: var(--font-size-sm);
  color: var(--color-text-muted);
  text-align: center;
  background: var(--color-bg-alt);
  border-top: 1px solid var(--color-border);
}

/* ===== SKILLS SECTION ===== */
.skills-categories {
  display: flex;
  flex-direction: column;
  gap: var(--spacing-lg);
  margin-top: var(--spacing-md);
}

.skill-category-block {
  background-color: var(--color-bg-alt);
  padding: var(--spacing-md) var(--spacing-lg);
  border-radius: var(--border-radius-lg);
  border-left: 3px solid var(--color-accent);
}

.skills-tag-row {
  display: flex;
  flex-wrap: wrap;
  gap: var(--spacing-sm);
  margin-top: var(--spacing-sm);
}

.skill-tag {
  background-color: var(--color-bg);
  border: 1px solid var(--color-border);
  padding: var(--spacing-xs) var(--spacing-sm);
  border-radius: var(--border-radius);
  font-size: var(--font-size-sm);
  color: var(--color-text-muted);
  transition: all var(--transition-fast);
}

.skill-tag:hover {
  border-color: var(--color-accent);
  color: var(--color-accent);
  background-color: var(--color-bg-alt);
}

/* ===== COMPETITION CARD ===== */
.competition-card {
  background-color: var(--color-bg);
  padding: var(--spacing-lg);
  border-radius: var(--border-radius-lg);
  border-left: 4px solid var(--color-success);
  box-shadow: var(--shadow-sm);
}

.competition-header {
  display: flex;
  align-items: center;
  gap: var(--spacing-sm);
  margin-bottom: var(--spacing-sm);
}

/* ===== SIDE PROJECTS - STRIPS ===== */
.project-strips {
  display: flex;
  flex-direction: column;
  gap: var(--spacing-md);
  margin-top: var(--spacing-lg);
}

.project-strip {
  display: flex;
  justify-content: space-between;
  align-items: center;
  padding: var(--spacing-md) var(--spacing-lg);
  background-color: var(--color-bg-alt);
  border-radius: var(--border-radius);
  border-left: 3px solid var(--color-secondary);
  transition: transform var(--transition-fast), box-shadow var(--transition-fast);
}

.project-strip:hover {
  transform: translateX(4px);
  box-shadow: var(--shadow-sm);
}

.strip-content { flex: 1; }

.strip-meta {
  font-size: var(--font-size-sm);
  color: var(--color-text-muted);
  margin-bottom: var(--spacing-xs);
  font-style: italic;
}

.strip-desc {
  font-size: var(--font-size-sm);
  color: var(--color-text-light);
  margin: 0;
}

.strip-link {
  font-weight: 500;
  font-size: var(--font-size-sm);
  white-space: nowrap;
  margin-left: var(--spacing-lg);
}

.strip-link::after {
  content: "→";
  margin-left: 4px;
  transition: transform var(--transition-fast);
}

.strip-link:hover::after {
  transform: translateX(3px);
}

/* ===== TUTORIAL STRIPS (COMPACT) ===== */
.compact-section { padding: var(--spacing-xl) 0; }

.tutorial-strips {
  display: flex;
  flex-direction: column;
  gap: var(--spacing-sm);
  margin-top: var(--spacing-md);
}

.tutorial-strip {
  display: flex;
  justify-content: space-between;
  align-items: center;
  padding: var(--spacing-sm) var(--spacing-md);
  background-color: var(--color-bg);
  border-radius: var(--border-radius);
  border: 1px solid var(--color-border);
  transition: all var(--transition-fast);
}

.tutorial-strip:hover {
  border-color: var(--color-accent);
  background-color: var(--color-bg-alt);
  transform: translateX(2px);
}

.tutorial-title {
  font-weight: 500;
  font-size: var(--font-size-md);
  color: var(--color-text);
}

.tutorial-desc {
  font-size: var(--font-size-sm);
  color: var(--color-text-muted);
}

/* ===== CONTACT SECTION ===== */
.contact-links {
  display: flex;
  flex-wrap: wrap;
  gap: var(--spacing-md);
  margin-top: var(--spacing-md);
}

.contact-link {
  background-color: var(--color-bg-alt);
  padding: var(--spacing-sm) var(--spacing-md);
  border-radius: var(--border-radius);
  font-weight: 500;
  font-size: var(--font-size-sm);
  display: inline-flex;
  align-items: center;
  gap: var(--spacing-xs);
  transition: all var(--transition-fast);
}

.contact-link:hover {
  background-color: var(--color-primary);
  color: var(--color-bg);
  transform: translateY(-1px);
}

/* ===== FOOTER ===== */
.site-footer {
  background-color: var(--color-bg-section);
  padding: var(--spacing-xl) 0;
  text-align: center;
  color: var(--color-text-muted);
  font-size: var(--font-size-sm);
}

.footer-note { margin-top: var(--spacing-sm); opacity: 0.8; }

/* ===== LINKS & UTILS ===== */
.link-arrow {
  display: inline-flex;
  align-items: center;
  gap: var(--spacing-xs);
  font-weight: 500;
  font-size: var(--font-size-sm);
  margin-top: var(--spacing-sm);
}
.link-arrow::after { content: "→"; transition: transform var(--transition-fast); }
.link-arrow:hover::after { transform: translateX(3px); }

.section-intro {
  margin-bottom: var(--spacing-lg);
  font-style: italic;
  color: var(--color-text-muted);
}

/* ===== RESPONSIVE DESIGN ===== */
@media (max-width: 768px) {
  .header-content { flex-direction: column; gap: var(--spacing-md); }
  .nav-links { flex-wrap: wrap; justify-content: center; gap: var(--spacing-sm); }
  
  .hero-content { flex-direction: column; text-align: center; }
  .hero-cta { justify-content: center; }
  
  .hero h1 { font-size: var(--font-size-2xl); }
  
  h2 { font-size: var(--font-size-xl); }
  
  .grid-2, .grid-3 { grid-template-columns: 1fr; }
  
  .experience-header { flex-direction: column; align-items: flex-start; }
  
  .project-links { flex-direction: column; align-items: flex-start; }
  .project-links .btn { width: 100%; max-width: 280px; }
  
  .contact-links { justify-content: center; }
  
  .project-strip { flex-direction: column; align-items: flex-start; gap: var(--spacing-sm); }
  .strip-link { margin-left: 0; }
  
  .tutorial-strip { flex-direction: column; align-items: flex-start; gap: var(--spacing-xs); }
}

@media (max-width: 480px) {
  :root { --font-size-base: 15px; }
  
  .hero { padding: var(--spacing-2xl) 0; }
  .hero h1 { font-size: var(--font-size-xl); }
  
  .section { padding: var(--spacing-xl) 0; }
  
  .project-card, .experience-card { padding: var(--spacing-md); }
  
  .profile-photo { width: 160px; height: 160px; }
}

/* ===== ACCESSIBILITY ===== */
@media (prefers-reduced-motion: reduce) {
  *, *::before, *::after {
    animation-duration: 0.01ms !important;
    transition-duration: 0.01ms !important;
  }
  html { scroll-behavior: auto; }
}

:focus { outline: 2px solid var(--color-accent); outline-offset: 2px; }
:focus:not(:focus-visible) { outline: none; }
:focus-visible { outline: 2px solid var(--color-accent); outline-offset: 2px; }

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

/* ===== ANIMATIONS ===== */
.slide-up {
  opacity: 0;
  transform: translateY(30px);
  transition: opacity var(--transition-slow), transform var(--transition-slow);
}
.slide-up.visible { opacity: 1; transform: translateY(0); }